BR112017004392B1 - PERISTALTIC PUMP - Google Patents

Abstract

APPARATUS AND METHOD FOR INFUSING FLUID THROUGH A TUBE BY SUITABLE HEATING OF THE TUBE. The present invention relates to a peristaltic pump described herein that includes a conduit, a plunger, a motor, and a heater. The conduit is configured to hold a tube (e.g., an IV tube). The plunger acts on the tube placed inside the conduit. The motor engages the plunger to actuate the plunger. The heater is arranged in thermal conductive contact with the tube. That is, the heater, either through direct or indirect application, heats the tube.

Description

CROSS REFERENCE TO RELATED ORDER

[0001] The present application is a Non-Provisional Application that claims the benefit of Provisional Patent Application serial number US 62/052,008, filed on September 18, 2014 and entitled APPARATUS AND METHOD FOR INFUSING FLUID THROUGH A TUBE BY APPROPRIATELY HEATING THE TUBE (attorney document number M93), which is incorporated herein by reference in its entirety.

BACKGROUND RELEVANT FIELD

[0002] The present description refers to the infusion fluid. More particularly, the present description relates to an apparatus for infusing fluid into a patient, for example, with the use of a pump.

DESCRIPTION OF RELATED TECHNIQUE

[0003] Providing patient care in a hospital generally requires the interaction of multiple healthcare professionals and professionals (e.g., doctors, nurses, pharmacists, technicians, clinical nurses, etc.) and any number of medical devices/systems for treatment of a given patient. Despite the existence of systems intended to facilitate the process of care, such as those incorporating electronic medical records ("EMR") and computerized provider order entry ("CPOE"), the process for providing comprehensive care to patients including ordering and Delivery of medical treatments, such as medications, is associated with several non-trivial issues.

[0004] Peristaltic pumps are used in a variety of applications such as medical applications, specifically fluid transfer applications that would benefit from isolation of system fluid and other fluids. Some peristaltic pumps work by length or by squeezing a length of flexible tubing. A mechanical mechanism pinches a portion of the tubing and pushes any fluid trapped in the tubing in the direction of rotation. They are rotary peristaltic pumps and finger peristaltic pumps.

[0005] Rotary peristaltic pumps typically move liquids through flexible tubing placed in an arc-shaped raceway. Rotary peristaltic pumps are generally made of two to four rollers placed on a roller conveyor rotatably driven by a motor. A typical rotary peristaltic pump has a rotor installation with pinch rollers that apply pressure to flexible tubing at closely spaced locations to provide a squeezing action on the tubing against an occlusion bed. Pipe occlusion creates increased pressure in front of the pinched area and reduced pressure behind that area, thus forcing a liquid through the pipe as the impeller installation moves the pinch roller along the pipe. In order to operate, there must always be an occlusion zone; in other words, at least one of the rollers is always pressing on the tube.

[0006] Peristaltic finger pumps are made of a series of fingers that move in a cyclic manner to flatten a flexible tube against a countersurface. The fingers move essentially vertically, in a wave-like fashion, forming an occlusion zone that moves upstream and downstream. The last finger — the most downstream — lifts when the first finger — the most upstream — presses against the countersurface. The most commonly used finger pumps are linear, meaning the countersurface is plate and the fingers are parallel. In this case, the fingers are controlled by a series of cams arranged one behind the other, with each cam cooperating with a finger. These cams are placed helically offset on a shared shaft rotatably driven by a motor. There are also peristaltic rotary finger pumps, which attempt to combine the advantages of roller pumps with those of finger pumps. In this type of bomb, the counter surface is not flat but arc-shaped and the fingers are arranged radially within the counter surface. In this case, a shared cam with multiple handles placed in the center of the arc is used to activate the fingers.

SUMMARY

[0007] In one embodiment of the present disclosure, a pump for pumping fluid includes a tube retainer, a plunger, an operating member, internal and external valves, an actuator mechanism, a position sensor and a processor. The plunger is configured for forward and reverse actuation relative to the tube retainer when the tube retainer is opposite the plunger. The tube retainer can retain an intravenous infusion tube. The operating member is configured to drive the plunger toward the tube retainer. Optionally, the plunger can be L-shaped plunger.

[0008] The inlet valve is upstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The outlet valve is downstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The actuator mechanism controls the actuation of the plunger, the inlet valve and the outlet valve. The position sensor estimates a piston position. The actuator mechanism may be or includes a cam shaft. The processor is coupled to the position sensor to receive the estimated position of the piston from it. The processor detects an anomaly based in part on the estimated position of the plunger when the inlet valve is in the occluder position and the outlet valve is in the occluder position. Processors can be configured to detect a leak based on a rate of change of the estimated plunger position.

[0009] The pump may also include a gas-sensitive ultrasonic sensor in an infusion tube. The ultrasonic sensor may be located downstream of the plunger and communicates with the processor. The processor distinguishes between an upstream occlusion and the presence of air in the fluid using the ultrasonic sensor. The processor can determine the volume of air pumped downstream based on the position of the plunger as both the inlet and outlet valves occlude the infusion tube and based on the trapped gas that is captured by the ultrasonic sensor.

[00010] The pump may include a housing and the door pivotally coupled to the housing. The door pivots to an open position and a closed position. The pipe retainer can be arranged in the door. The tube retainer, port and plunger are configured so that the plunger is configured to actuate the forward and reverse direction of the infusion tube when the port is in a closed position.

[00011] The pump may include a lever pivotally coupled to the door and has at least first and second positions. The pump may also include a latch attached to the port. The lever hooks the door into the housing when in the first position. The first position may be a position where the lever is pivoted toward the door.

[00012] The pump may include a carrier having a first and a second part pivotally coupled together. The door and conveyor co-pivot together. The housing includes a first slot in which the first portion of the carrier is at least partially disposed when the door is in the open position and a second slot in which the second portion of the carrier is disposed when the door is in the open position. The lever is functionally coupled to the second portion of the conveyor so that when the door is in the closed position, actuation of the lever toward the first position pushes the first and second portions of the conveyor into the first slot of the housing.

[00013] The actuator mechanism may include a cam shaft, an inlet valve cam, an outlet valve cam and a plunger. The inlet valve cam is coupled to the cam shaft and actuates the inlet valve. The output valve cam is coupled to the cam shaft and actuates the output valve. The plunger cam is coupled to the cam shaft to actuate the plunger. The plunger cam is configured to lift the plunger from the tube retainer. The processor can detect the anomaly when just one force from the operating member forces the plunger toward the tube retainer. The processor may communicate data (e.g., the anomaly) to a monitoring client. That is, the data may include an indication of the anomaly.

[00014] In yet another embodiment of the present disclosure, a pump includes a tube retainer, a plunger, an operating member, inlet and outlet valves, an actuator mechanism, a pressure sensor and a processor. The plunger is configured to operate in the forward and backward direction of the infusion tube when the tube retainer is positioned opposite the plunger. The operating member drives the plunger toward the tube retainer. The inlet valve is upstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The outlet valve is downstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The actuator mechanism is configured to control the actuation of the plunger, the inlet valve and the outlet valve. The pressure sensor is disposed adjacent to at least one of the inlet valve, the outlet valve and the plunger. The processor is coupled to the pressure sensor to receive a pressure signal from the pressure sensor. The inlet valve, outlet valve and plunger are configured to pump fluid in a plurality of cycles, wherein each cycle has a plateau pressure level and a peak pressure level. The processor is configured to, using the pressure signal, determine whether a downstream occlusion exists when a difference between a peak pressure level and a plateau pressure level is greater than a predetermined threshold in one cycle of the plurality of cycles. The cycle of the plurality of cycles may be a single cycle. The pressure signal can be filtered before being received by the processor. The pump may include an analog filter configured to filter the pressure signal before it is received by the processor. Additionally or alternatively, the processor is configured to digitally filter the pressure signal before determining whether a downstream occlusion exists.

[00015] In yet another embodiment, a pump for pumping fluid includes a tube retainer, a plunger, an operating member, inlet and outlet valves, an actuator mechanism, a pressure sensor, and a processor. The plunger is configured for forward and backward actuation relative to the tube retainer when the tube retainer is disposed opposite the plunger. The operating member drives the plunger toward the tube press. The inlet valve is upstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The outlet valve is downstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The actuator mechanism controls the actuation of the plunger, the inlet valve and the outlet valve. The pressure sensor is disposed adjacent to at least one of the inlet valve, the outlet valve and the plunger. The processor is coupled to the pressure sensor to receive a pressure signal from the pressure sensor. The inlet valve, outlet valve and plunger are configured to pump fluid in a plurality of cycles, wherein each cycle has a plateau pressure level and a peak pressure level. The processor is configured to, using the pressure signal, determine whether a downstream occlusion exists when a difference between a first plateau pressure level of a first cycle and a plateau pressure level of a second cycle is greater than a predetermined threshold.

[00016] The processor may be one or more of a microprocessor, a microcontroller, a PLD, a PLA, a CPLD and/or an FPGA. The first and second cycles are cycles of the plurality of cycles. The first and second cycles can be sequential cycles.

[00017] The pressure signal can be filtered before being received by the processor. The pump may include an analog filter configured to filter the pressure signal before it is received by the processor. The processor can digitally filter the pressure signal before determining whether there is an occlusion downstream.

[00018] In yet another embodiment, a pump for pumping fluid includes a tube retainer, a plunger, an operating member, inlet and outlet valves, an actuator mechanism, a pressure sensor, and a processor. The plunger is configured for forward and backward actuation relative to the tube retainer when the tube retainer is disposed opposite the plunger. The operating member drives the plunger toward the tube retainer. The inlet valve is upstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The outlet valve is downstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The actuator mechanism controls the actuation of the plunger, the inlet valve and the outlet valve. The pressure sensor is disposed adjacent to at least one of the inlet valve, the outlet valve and the plunger. The processor is coupled to the pressure sensor to receive a pressure signal from the pressure sensor. The inlet valve, outlet valve and plunger are configured to pump fluid in a plurality of cycles, wherein each cycle has a plateau pressure level and a peak pressure level. The processor is configured to, using the pressure signal, determine whether a downstream occlusion exists when a sum of each of the plateau-to-plateau pressure values of the plurality of cycles is greater than a predetermined threshold.

[00019] The pressure signal can be filtered before being received by the processor. The pump may include an analog filter configured to filter the pressure signal before it is received by the processor and/or a digital filter within the processor that filters the pressure signal before determining whether a downstream occlusion exists.

[00020] The processor may add an adjustment value to the sum such that the sum represents a difference between a plateau level of a current cycle of the plurality of cycles relative to a lowest plateau value among all cycles of the plurality of cycles. cycles.

[00021] In yet another embodiment, a pump for pumping fluid includes a tube retainer, a plunger, an operating member, inlet and outlet valves, an actuator mechanism, a pressure sensor, and a processor. The plunger is configured for forward and backward actuation relative to the tube retainer when the tube retainer is disposed opposite the plunger. The operating member drives the plunger toward the tube retainer. The inlet valve is upstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The outlet valve is downstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The actuator mechanism controls the actuation of the plunger, the inlet valve and the outlet valve. The pressure sensor is disposed adjacent to at least one of the inlet valve, the outlet valve and the plunger. The processor is coupled to the pressure sensor to receive a pressure signal from the pressure sensor. The inlet valve, outlet valve and plunger are configured to pump fluid in a plurality of cycles, wherein each cycle has a minimum pressure level and a peak pressure level. The processor is configured, using a pressure signal, to determine whether a downstream occlusion exists when a plateau of one cycle of the plurality of cycles is greater than a lowest plateau among all cycles of the plurality of cycles by a predetermined amount.

[00022] The pressure signal can be filtered before being received by the processor. The pump may include an analog filter configured to filter the pressure signal before it is received by the processor. The processor can digitally filter the pressure signal before determining whether there is an occlusion downstream.

[00023] In yet another embodiment, a pump for pumping fluid includes a tube retainer, a plunger, an operating member, inlet and outlet valves, an actuator mechanism, a pressure sensor, and a processor. The plunger is configured for forward and backward actuation relative to the tube retainer when the tube retainer is disposed opposite the plunger. The operating member drives the plunger toward the tube retainer. The inlet valve is upstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The outlet valve is downstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The actuator mechanism controls the actuation of the plunger, the inlet valve and the outlet valve. The pressure sensor is disposed adjacent to at least one of the inlet valve, the outlet valve and the plunger. The processor is coupled to the pressure sensor to receive a pressure signal from the pressure sensor. The inlet valve, outlet valve and plunger are configured to pump fluid in a plurality of cycles, wherein each cycle has a minimum pressure level and a peak pressure level. The processor is configured to, using the pressure signal, determine whether a downstream occlusion exists when a difference is greater than a predetermined threshold where the difference is a subtraction of: (1) a filtered value from a sequential series of sequential plateau-to-plateau pressure values of the plurality of cycles from (2) a plateau-to-plateau value.

[00024] The pressure signal can be filtered before being received by the processor. The pump may include an analog filter configured to filter the pressure signal before it is received by the processor. The processor can digitally filter the pressure signal before determining whether there is an occlusion downstream.

[00025] In yet another embodiment, a pump for pumping fluid includes a tube retainer, a plunger, an operating member, inlet and outlet valves, an actuator mechanism, a pressure sensor, and a processor. The plunger is configured for forward and backward actuation relative to the tube retainer when the tube retainer is disposed opposite the plunger. The operating member drives the plunger toward the tube retainer. The inlet valve is upstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The outlet valve is downstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The actuator mechanism controls the actuation of the plunger, the inlet valve and the outlet valve. The pressure sensor is disposed adjacent to at least one of the inlet valve, the outlet valve and the plunger. The processor is coupled to the pressure sensor to receive a pressure signal from the pressure sensor. The inlet valve, outlet valve and plunger are configured to pump fluid in a plurality of cycles, wherein each cycle has a plateau pressure level and a peak pressure level. The processor is configured, using the pressure signal, to: (1) determine whether a downstream occlusion exists if a difference between a peak pressure level and a plateau pressure level is greater than a threshold in any cycle among the plurality of cycles, (2) determining whether downstream occlusion exists if a difference between a first plateau pressure level of a first cycle and a second plateau pressure level of a second cycle is greater than a second predetermined threshold , where the first and second cycles are cycles of the plurality of cycles, (3) determine whether occlusion exists downstream if a plateau of the cycle of the plurality of cycles is greater than a smaller plateau among all cycles of the plurality of cycles by a third predetermined threshold, and (4) determine whether downstream occlusion exists if a subtraction of a filtered value from a sequential series of sequential plateau-to-plateau pressure values from the plurality of cycles of a plateau-to-plateau value is greater than a fourth predetermined threshold.

[00026] The processor may perform all assessments (1) to (4) to determine whether downstream occlusion exists. The processor is configured to communicate data to a monitoring client. The pressure signal can be filtered before being received by the processor. The pump may include an analog filter configured to filter the pressure signal before it is received by the processor. The processor can digitally filter the pressure signal before determining whether there is an occlusion downstream.

[00027] The actuator mechanism may further include an inlet valve cam coupled to the cam shaft configured to actuate the inlet valve; an output valve cam coupled to the cam shaft configured to actuate the output valve; and a plunger cam coupled to the cam shaft configured to actuate the plunger. The plunger cam can be configured to lift the plunger in a reverse direction relative to the tube retainer. The plunger cam can be configured so that the plunger cam can only compress the operating member and not force the plunger toward the tube retainer.

[00028] The plunger cam can be configured to actuate only the plunger in the direction of retreat relative to the tube retainer against the operating member and the plunger cam and the operating member are configured so that only one force from the operating member can press a tube disposed within the tube retainer.

[00029] In another embodiment of the present description, a pump includes a tube retainer and a plunger. The plunger is configured to actuate toward the tube retainer. One end of the plunger has a rounded end and a bottom of the tube retainer has a generally U-shape that provides a radial gap between the plunger and the tube retainer approximately equal to two to three times the wall thickness of a tube. of infusion. A minimum distance between the plunger and the tube retainer along a path of movement of the plunger may be limited by a surface on the tube retainer that contacts a portion of the plunger.

[00030] In another embodiment, a pump includes a tube retainer and a plunger. The tube press defines a wall end and a first contact section. The plunger is configured to actuate toward the tube retainer. The plunger has a rounded tip and a second contact section. The tube press and plunger are configured so that actuation of the plunger toward the tube retainer is prevented when the first and second contact sections come into contact with each other. The first and second contact sections may be configured to contact each other to leave a predetermined gap between the wall of the tube retainer and the rounded tip of the plunger.

[00031] The predetermined gap can be configured to prevent an infusion tube disposed within the tube retainer from closing completely. The predetermined gap may be configured to cause an infusion tube disposed within the tube retainer to partially occlude the flow of fluid within the infusion tube.

[00032] In another embodiment, a pump includes a tube retainer and a plunger. The tube retainer defines a wall end and a first contact section. The plunger is configured to actuate toward the tube retainer and the plunger has a rounded tip and a second contact section. The tube retainer and plunger are configured so that actuation of the plunger toward the tube retainer is prevented when the first and second contact sections come into contact with each other. The first and second contact sections come into contact with each other so that a gap between the rounded tip and the tube retainer is approximately equal to about eight percent greater than twice a wall thickness of an infusion tube arranged inside the tube retainer. The rounded tip may have a width that is less than an uncompressed tube diameter of a tube disposed within the cavity of the tube retainer. The tube retainer may be configured to receive a predetermined range of infusion tube sizes and/or the tube retainer may be configured to receive a predetermined infusion tube size.

[00033] In yet another embodiment of the present description, a pump includes a tube retainer defining a cavity and a plunger configured to actuate toward the tube retainer. The plunger has a rounded tip. The rounded tip may have a width that is less than an uncompressed tube diameter of a tube disposed within the cavity of the tube retainer. The tube retainer can be configured to receive a predetermined infusion tube size. In another embodiment, the rounded tip may have a radius that is smaller than an uncompressed tube radius of a tube disposed within the cavity of the tube retainer.

[00034] In another embodiment, a pump includes a tube retainer defining a cavity and a first contact section and a plunger configured to actuate toward the tube retainer. The plunger has a rounded tip and a second contact section. The tube retainer and plunger are configured so that actuation of the plunger toward the tube retainer is prevented when the first and second contact sections come into contact with each other. The first and second contact sections contact each other so that a gap between the rounded tip and the tube retainer is approximately equal to slightly greater than twice a wall thickness of a tube disposed within the cavity. The tube retainer can be configured to receive a predetermined infusion tube size.

[00035] In another embodiment of the present description, the pump includes a housing, a door, a conveyor and a lever handle. The housing has a first slot. The port is pivotally coupled to the housing and has a plate configured to receive a tube. The door is configured to have a closed position and an open position. The door includes a second slot. The carrier has a pivot defining a first and a second portion pivotally coupled together. The first portion is slidably disposed within the first slot of the housing and the second portion is slidably disposed within the second slot when the door is open. The lever handle is pivotally coupled to the door and is functionally coupled to the conveyor.

[00036] The pump may also include a valve configured to occlude the tube. The carrier may be configured to retain the slide occluder. When the door is in the closed position and the lever handle is in a fully open position, the conveyor is configured to retain the slide occluder within the first and second portions so that the slide occluder occludes the tube. An initial actuation of the lever handle towards the housing actuates the valve to occlude the tube prior to actuation of the conveyor in the first port slot so that the tube is not occluded by the slide occluder.

[00037] The lever handle can be functionally coupled to the second portion of the conveyor so that actuation of the lever handle in the direction of retreat from the housing moves the first and second portions of the conveyor in the direction of retreat from the first slot to thereby move a sliding occluder disposed within the conveyor in an occluded position so that at least part of the actuation of the lever handle in the direction of retreat from the housing occurs without moving the sliding occluder.

[00038] The door may be pivotally coupled to the housing by means of a hinge, the door may contain a face of the housing when the door is in the closed position, and the hinge may be configured to allow the door to move relative to the housing. from a position perpendicular to the face of the housing when the door is in the open position to adjacent to the face of the housing when the door is in the closed position.

[00039] The second portion of the carrier can be switched to receive a slide occluder in only a predetermined orientation. The door defines a key for the second portion of the carrier such that the second portion of the carrier receives a slide occluder in only one predetermined orientation.

[00040] The pump may include a slide occluder sensor configured to detect a presence of a slide occluder when the slide occluder is properly inserted into the conveyor, the door is closed and the lever handle is actuated completely toward the door.

[00041] In some embodiments, the pump may also include a valve configured to occlude the tube. The carrier is configured to retain a slide occluder. When the door is in the closed position and the lever handle is in a fully open position, the conveyor is configured to retain the slide occluder within the first and second portions so that the slide occluder completely occludes the tube. An initial actuation of the lever handle when the lever handle is in a fully closed position toward the retreat of the housing actuates the conveyor to an occluding position before actuating the valve to a non-occlusive position.

[00042] In some embodiments, the pump may also include a valve configured to occlude the tube. The carrier is configured to retain a slide occluder. When the door is in the closed position and the lever handle is in a completely closed position, the conveyor is configured to retain the slide occluder within the first and second portions so that the slide occluder completely occludes the tube. An initial actuation of the lever handle in the housing's retreating direction actuates the conveyor to an occluding position before actuating the valve to a non-occlusive position. The door may become unhooked from the housing after a substantial amount of actuation of the lever handle in the direction of door retraction.

[00043] In yet another embodiment of the present description, a pump includes a housing, a door and a conveyor. The housing has a first slot. The port is pivotally coupled to the housing and has a plate configured to receive a tube. The door is configured to have a closed position and an open position and includes a second slot. The carrier has a pivot defining first and second portions pivotally coupled together, wherein the first portion is slidably disposed within the first slot of the housing and the second portion is slidably disposed within the second slot of the door when the door is open.

[00044] In another embodiment of the present description, a pump includes a pumping mechanism, a motor, a rotation sensor, a counter and a first and a second processor. The pumping mechanism is configured to pump fluid. The motor is coupled to the pumping mechanism to actuate the pumping mechanism. The rotation sensor is coupled to the motor and is configured to generate a plurality of pulses wherein each pulse of the plurality of pulses indicates a rotation (e.g., a full rotation or a partial rotation, such as 2 degrees) of the motor. The counter is coupled to the rotation sensor to count each pulse of the plurality of pulses. The first processor is functionally coupled to the rotation sensor to monitor the plurality of pulses. The second processor is functionally coupled to the counter to monitor the counted pulses of the plurality of pulses. The first and second processors are in operational communication with each other. The first and second processors are configured to determine whether the monitored plurality of pulses determined by the first processor correspond to the counted pulses as received by the second counter processor.

[00045] The monitored plurality of pulses determined by the first processor corresponds to the counted pulses as received by the second counter processor when the monitored plurality of pulses determined by the first processor corresponds to the pulses as received by the second counter processor by a predetermined amount. The predetermined amount may be a percentage amount, a predetermined number of pulses of the plurality of pulses, and/or a predetermined angular value. Each pulse of the plurality of pulses may correspond to a predetermined number of degrees of rotation by the motor.

[00046] The first processor may communicate a contact number of the monitored plurality of pulses to the second processor. The first processor may use the monitored plurality of pulses to determine a first estimated amount of volume delivered. The second processor may use the counted pulses of the plurality of pulses to determine a second estimated amount of volume delivered. One or both of the first and second processors may issue an alarm when the first and second estimated delivered volume quantities do not correspond to a predetermined quantity.

[00047] In another embodiment, the pump includes a pumping mechanism, a motor, a rotation sensor, a counter and a first and a second processor. The pumping mechanism is configured to pump fluid. The motor is coupled to the pumping mechanism to actuate the pumping mechanism. The sensor sensor is coupled to the motor and is configured to generate a plurality of pulses. Each pulse of the plurality of pulses may indicate a rotation of the engine. The counter is coupled to the rotation sensor and counts each pulse of the plurality of pulses. The first processor is functionally coupled to the rotation sensor to monitor the plurality of pulses to estimate a first volume of pumped fluid. The second processor is functionally coupled to the counter to monitor the counted pulses of the plurality of pulses to estimate a second volume of pumped fluid. The first and second processors are in operational communication with each other. The first and second processors are configured to determine whether the first estimated volume of pumped fluid is within a predetermined range relative to the second estimated value of pumped fluid. The first processor can control the operation of the engine. The second processor can control the operation of the engine. The second processor may be coupled to a user interface to receive user input therefrom.

[00048] The predetermined range may be a percentage amount relative to one of the first and second estimated volumes of pumped fluid, a range relative to the first estimated volume of pumped fluid, and/or a range relative to the second estimated volume of pumped fluid.

[00049] One or both of the first and second processors may issue an alarm when the first and second estimated volumes of pumped fluid are within a predetermined range. The first processor may communicate the first estimated volume of pumped fluid to the second processor so that the second processor determines whether the first estimated volume of pumped fluid is within the predetermined range relative to the second estimated volume of pumped fluid. The second processor may communicate the second estimated volume of pumped fluid to the first processor such that the first processor determines whether the first estimated volume of pumped fluid is within the predetermined range relative to the second estimated volume of pumped fluid.

[00050] In another embodiment of the present disclosure, a pump for pumping fluid includes a housing, a port, a tube retainer, a plunger, a valve, one or more hook tabs and a lever. The housing has one or more pins. The door is pivotally coupled to the housing. The tube retainer is arranged in the port. The plunger is configured to actuate toward and away from the infusion tube when the tube retainer is disposed opposite the plunger. The valve is disposed upstream or downstream of the plunger and is configured to actuate between an occluder position and an occluder position. The lever handle is functionally coupled to one or more hook tabs to actuate the one or more hook tabs to lock the one or more pins of the housing.

[00051] The pump may include a spring configured to propel the door toward the housing when the one or more hook latches are locked onto the one or more pins. The spring may be a leaf spring and may provide mechanical engagement between at least one hook latch and the door. Actuating the lever handle to hook the one or more hook tabs to the one or more pins may also actuate the valve to occlude a tube. Actuation of the lever handle to disengage the one or more hook tabs from the one or more pins may also actuate the valve to a non-occlusive position. An operating member may be configured to drive the plunger toward the tube retainer.

[00052] In another embodiment of the present description, a pump includes a housing and a port. The housing has a front and first and second sides. The door is pivotally coupled to the first side and defines a cut-out portion. The pump may include a lever handle pivotally coupled to the port. The pump may have a damper coupled to the first side of the housing and disposed within the cut-out portion of the door when the door is in a closed position. The lever handle includes a lever cutout portion positioned so that the damper is disposed within the lever cutout portion when the door is in the closed position and the lever handle is in a closed position.

[00053] In another embodiment of the present description, a pump includes a housing, a user interface and an extended light source. The housing has a front and first and second sides. The user interface is functionally coupled to the front of the housing. The elongated light source is coupled at least partially to the throne of the user interface. The elongated light source may include a plurality of LEDs and a light diffuser. The elongated light source can be arranged completely around an outer periphery of the user interface. A processor may be functionally coupled to the elongated light source. The processor can be configured to control the elongated light source. The processor may be configured to indicate a pump condition by controlling the elongated light source, for example, by changing a color of the elongated light source and/or by changing a brightness of the elongated light source.

[00054] In another embodiment of the present description, a pump includes a housing and a power supply. The power supply is coupled to the housing so that the housing is configured as a heat sink. The pump may be a peristaltic pump and/or a syringe pump. The housing may be cast and may comprise at least one metal. The accommodation can be a unitary body. The pump may include a motor such that the motor is coupled to the housing such that the housing is a heat sink for the motor.

[00055] In another embodiment of the present description, a pump includes a tube retainer, a plunger, a cam shaft, a motor, a position sensor, a rotation sensor and a processor. The plunger has a cam follower and is configured for forward and reverse actuation relative to the tube retainer when the tube retainer is disposed opposite the plunger. A camshaft has a plunger cam attached to the camshaft. The plunger cam follower is configured to engage the plunger cam so that rotation of the cam shaft actuates the plunger. The pump may include an operating member configured to drive the plunger toward the tube retainer. The motor is functionally coupled to the camshaft to rotate the camshaft. The position sensor is configured to provide a first signal corresponding to a position of the piston. The rotation sensor is configured to provide a second signal corresponding to the rotation of the camshaft. The processor is coupled to the position sensor and rotation sensor to receive the first and second signals, where the processor determines whether the first signal corresponds to the second.

[00056] The processor can be configured to continue operating the engine when one of the first and second signals is inoperative. The processor can be configured to ignore the dead signal among the first and second signals.

[00057] The pump may include an engine speed sensor configured to provide a third signal to the processor. The third signal corresponds to the engine speed. The processor can be configured to determine whether the first, second and third signals correspond to each other.

[00058] The processor can be configured to continue operating the engine when one of the first, second and third signals is inoperative. The processor can be configured to ignore the inoperative signal among the first, second and third signals.

[00059] The pump may include a redundant position sensor configured to provide a fourth signal corresponding to the position of the plunger. The processor receives the fourth signal. The processor can be configured to continue to operate the engine when one of the first, second and fourth signals is inoperative. The processor can be configured to ignore the dead signal among the first, second and fourth signals.

[00060] In another embodiment of the present description, a pump includes a tube retainer, inlet and outlet valves, a cam shaft, a motor and a processor. The plunger is configured to actuate toward and away from the tube retainer when the tube retainer is disposed opposite the plunger. The inlet valve is upstream of the plunger and is configured to actuate between an occluder position and a non-occluder position. The outlet valve is downstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The camshaft is configured to actuate the plunger, inlet valve, and outlet valve. The engine is functionally coupled to the camshaft. The processor is functionally coupled to the engine and is configured to control the engine. The processor is configured to threshold at least one of an inlet valve lift, an outlet valve lift, and a plunger lift below a predetermined speed. The predetermined speed is selected to prevent outgassing of a fluid within a tube disposed in the tube retainer. The predetermined speed is a function of a position of at least one of the inlet valve, the outlet valve and the piston. The predetermined speed may be lower than a natural expansion speed of a tube disposed in the tube retainer.

[00061] A pump includes a tube retainer, a plunger, an operating member, inlet and outlet valves, an actuator mechanism, a position sensor, an in-line air sensor, and a processor. The plunger is configured to actuate toward and away from the infusion tube when the tube retainer is disposed opposite the plunger. The operating member is configured to drive the plunger toward the tube retainer. The inlet valve is upstream of the plunger and is configured to actuate between an occluder position and a non-occluder position. The outlet valve is downstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The actuator mechanism is configured to control the actuation of the plunger, inlet valve and outlet valve. The inlet valve, outlet valve and plunger are configured to pump fluid in a plurality of cycles, wherein each cycle has a plateau pressure level and a peak pressure level. Each cycle has an initial pressurization period corresponding to a total volume measurement taken when the inlet and outlet valves are closed and only the operating member applies a force to the plunger toward the tube retainer. The position sensor is functionally coupled to the plunger and is configured to measure a position of the plunger to determine the total volume measurement. The position sensor may provide a first signal corresponding to the position of the piston. The in-line air sensor is positioned downstream of the plunger and is configured to detect air. The in-line air sensor provides a second signal corresponding to air. The processor is coupled to the position sensor to receive the first signal and to the in-line air sensor to receive the second signal. The processor is configured to determine whether an underfill condition has occurred when the position of the plunger is within a predetermined range of the tube retainer as indicated by the first signal during the initial pressurization period of a cycle of the plurality of cycles. The actuating mechanism may be a cam shaft.

[00062] The processor can determine whether the underfill condition is air within a fluid tube using the second signal when the outlet valve is open. The processor can determine whether the underfill condition is from an upstream occlusion using the second signal when the outlet valve is open. The processor can determine whether the underfill condition is from an empty upstream fluid source using the second signal when the outlet valve is open.

[00063] In another embodiment of the present description, a pump for pumping fluid includes a housing, a user interface and a gesture recognition apparatus. The user interface is coupled to the housing. The gesture recognition apparatus is configured to recognize at least one gesture performed near the user interface. The pumping mechanism is configured to pump fluid. The processor is coupled to the user interface and the gesture recognition device. The processor is configured to present a user with at least one option via the user interface and receive an option selected from the at least one option via the gesture recognition apparatus. The pumping mechanism may be a peristaltic pumping mechanism and/or a syringe pump mechanism.

[00064] In another embodiment of the present description, a pump includes a housing, a user interface, a pumping mechanism and a processor. The user interface is coupled to the housing. The pumping mechanism is configured to pump fluid. The processor coupled to the user interface is configured to provide a plurality of pump parameter inputs wherein each input of the plurality of pump parameter inputs is configured to receive a user-entered parameter. The processor is configured to determine whether all user-entered parameters of all parameters of the plurality of pump parameters meet at least one predetermined safety criterion. Each entry of the plurality of pump parameter inputs may be present without another entry of the plurality of pump parameter inputs.

[00065] In another embodiment of the present description, a pump includes a housing, a user interface, a pumping mechanism and a processor. The user interface is coupled to the housing. The pumping mechanism can be configured to pump fluid. The processor is coupled to the user interface. The processor may be configured to provide a plurality of pump parameter inputs, wherein each input of the plurality of pump parameter inputs is configured to receive a user-entered parameter, wherein the processor is configured to require that all inputs of the plurality of pump parameter inputs are entered within a predetermined period of time. The processor may be configured to receive a user-entered parameter corresponding to the plurality of pump parameter inputs in any order.

[00066] In yet another embodiment of the present disclosure, the pump for pumping fluid includes a tube retainer, a plunger, an actuator mechanism, a light source, an image sensor and a processor. The plunger is configured to actuate toward and away from the tube retainer when the tube retainer is disposed opposite the plunger. The actuator mechanism is configured to control the actuation of the plunger. The light source is configured to emit light toward or adjacent to the tube retainer. The image sensor is configured to receive light. The processor is in operative communication with the image sensor to receive image data and is configured to estimate a parameter of a tube disposed in the tube holder in accordance with the image data.

[00067] The light source can be arranged inside the plunger. The plunger may be at least one of transparent and translucent in the light of the light source.

[00068] The light source may be disposed adjacent to the piston and the piston is at least one of transparent and translucent to the light of the light source. The light source and plunger may be configured so that light from the light source travels from the light source through the plunger toward the tube retainer.

[00069] The pump may include a first polarizer positioned to polarize light from the light source before it is emitted into the tube retainer. The pump may include a second polarizer positioned to polarize light from the light source before it enters the image sensor. The first and second polarizers can be configured to polarize light in directions orthogonal to each other.

[00070] In some embodiments, the tube parameter is determined using a birefringence effect.

[00071] The tube parameter can be an identification of a particle disposed within the tube, an identification of a liquid disposed within the tube, a determined material of the tube, a volume of fluid within the tube along a predetermined portion of the tube , an identification of a bubble within a liquid disposed within the tube and/or whether the tube is present in the tube retainer. The tube parameter can be used to calibrate a pump control system.

[00072] The processor and image sensor can be configured to estimate the parameter using a color spectrum of light affected by the birefringence effect. The processor and image sensor can be configured to estimate the parameter using a moiré pattern of light affected by the birefringence effect.

[00073] In some embodiments, the pump further comprises a first pattern positioned to affect light from the light source before it is emitted into the tube retainer. The pump may also include a second pattern positioned to affect light from the cavity before it enters the image sensor. The tube parameter is determined using a moiré pattern as seen from the image sensor.

[00074] The second pattern can be arranged adjacent to the tube and is deformed by compression of the tube against the tube retainer when the plunger is actuated towards the tube retainer.

[00075] The light source can be a monochromatic light source.

[00076] In yet another embodiment of the present disclosure, the pump for pumping fluid includes a tube retainer, a plunger, an actuator mechanism, a layered structure, an image sensor and a processor. The plunger is configured for forward and backward actuation relative to the tube retainer when the tube retainer is disposed opposite the plunger. The actuator mechanism can be configured to control the actuation of the plunger. The layered structure has a waveguide layer and a diffuser layer and is configured for positioning against a tube to indicate a parameter of the tube. The image sensor is configured to receive light from the layered structure. The processor is in operative communication with the image sensor to receive image data. The processor is configured to estimate the parameter of the tube disposed in the tube retainer in accordance with the image data.

[00077] The layered structure may include a plurality of waveguide layers and a plurality of diffuser layers to determine a plurality of tube parameters. The layered structure can provide the selected tube parameter from the group of a polarization, an orientation and a color. The waveguide layer may be configured to be disposed against the tube so that light is diverged within the waveguide towards the tube.

[00078] In another embodiment of the present disclosure, the pump for pumping fluid includes a tube retainer, a plunger, an operating member, inlet and outlet valves, an actuator mechanism, a position sensor and a processor. The plunger is configured for forward and backward actuation relative to the tube retainer when the tube retainer is disposed opposite the plunger. The operating member may be configured to drive the plunger toward the tube retainer. The inlet valve is upstream of the plunger and is configured to actuate between an occluder position and a non-occluder position. The outlet valve is downstream of the plunger and is configured to actuate between an occluding position and a non-occlusive position. The actuator mechanism can be configured to control the actuation of the plunger, inlet valve, and outlet valve. The inlet valve, outlet valve, and plunger may be configured to pump fluid in a plurality of cycles wherein each cycle has an initial pressurization period corresponding to a total volume measurement taken when the inlet and outlet valves are closed. and only the operating member applies a force to the piston towards the tube retainer. The position sensor may be functionally coupled to the plunger and is configured to measure a position of the plunger to determine the total volume measurement. The position sensor may provide a first signal corresponding to the position of the piston. The processor may be coupled to the position sensor to receive the first signal and the processor is configured to determine a head height of a fluid source coupled to a fluid tube disposed within the tube retainer using the first signal corresponding to the plunger position.

[00079] In yet another embodiment of the present disclosure, a medical device includes a user interface, an antenna, and a split ring resonator. The user interface has a front side and a back side. The antenna may be disposed orthogonally to a surface defined by the rear side of the user interface. The split ring resonator may be disposed at a distance from the user interface and configured to operate with the antenna.

[00080] The user interface may include a sensor with a touch screen. A frame may surround the touch screen sensor and has a gap so that the frame defines the split ring resonator. A dielectric can be disposed within the gap.

[00081] In yet another embodiment of the present description, a pump includes a housing, a door, a lever and a lock. The housing has a pin. The door is pivotally coupled to the housing. The lever has a pawl configured to engage the lever on the housing pin and the lever is pivotally coupled to the door. The lock can be configured to lock the lever when in an open position and the door is in an open position. The pump may include a conveyor operatively coupled to the lever.

[00082] The carrier may include a first portion and a second portion pivotally coupled to the first portion. The first portion may be positioned within a slot of the housing. The second portion may be positioned within a slot of the door. The first and second portions are configured to retain a slide occluder.

[00083] In some embodiments of the present disclosure, a peristaltic pump includes a raceway, a plunger, a motor, and a heater. The track is configured to hold a tube. The plunger is configured to act on the tube arranged within the raceway. The motor is configured to engage the plunger to actuate the plunger. The heater is arranged in thermoconductive contact with the tube.

[00084] The heater may be arranged on the piston. For example, the heater may be disposed on a rear part of the piston; wherein the rear part of the piston is on an opposite side of the piston away from the race.

[00085] The pump may include a rocker arm coupled to the plunger. The heater is arranged between the rocker arm and the plunger at the rear of the plunger. A temperature sensor (e.g. a thermistor) may be disposed on the piston. The temperature sensor can be configured to measure a temperature of the tube disposed within the race, measure a heater temperature and/or a plunger temperature.

[00086] In some embodiments, the heater may be disposed within the race and is configured to heat a tube retained within the race. The heater may be part of a plurality of heaters such that each heater of the plurality of heaters is in thermoconductive contact with the tube. Each of the heater parts can be arranged at different points, for example, on the raceway, on the piston or adjacent to the tube in the pump body, for example. The clue may be laid out on the door.

[00087] The pump may further include a controller configured to control the heating of the heater, and the temperature sensor may be configured to detect the heat generated by the heater. The heater controller can be configured to control the heater to reach a target temperature when the pump is programmed to operate beyond a limit flow rate or can be configured to control the heater to reach a target temperature when the pump cannot. achieve a target flow rate without activating the heater. The pump may include a display configured to display a message to plug a power cord attached to the pump into a power source when the heater is activated.

[00088] An insulator may be disposed adjacent to the heater, and the insulator may be configured to direct heat flow from the heater to the tube. The heater may be disposed on the plunger, and the insulator may be disposed on a side of the heater opposite a side facing the tube.

[00089] The pump may include an amplifier to amplify a plurality of pulses from the amplifier n to amplify the plurality of current pulses before they are sent to the heater to heat the heater (e.g., to a predetermined temperature).

[00090] The predetermined temperature can be selected to achieve a predetermined maximum flow error rate of the controller when controlling the actuation of the plunger to move the fluid through the tube. The predetermined temperature can be selected based on a pipe material. The predetermined temperature can be selected in accordance with a plurality of tube types, for example, so that each tube type of the plurality of tube types affects an error flow rate depending on the predetermined temperature. The predetermined temperature can be selected to minimize a flow rate error across the plurality of pipe types.

[00091] The plunger may be a spring-driven plunger configured to use a spring to impel a volume of fluid to be discharged by the plunger. A delta movement of the plunger from a full fill volume to a full discharge volume is correlated to a fluid discharge volume.

[00092] The correlation between the delta movement of the plunger and the fluid discharge volume may correspond to a predetermined temperature selected to minimize the maximum error flow rate of the plurality of tube types. A tube type of the plurality of tube types is established as a function of a material of a wall of a respective tube of the plurality of tube types.

[00093] 40. The pump of claim 1, wherein the plunger is a spring-driven plunger configured to use a spring to impel a volume of fluid to be discharged by the plunger, wherein a delta movement of the plunger A full fill volume to a full flush volume correlates to an estimated fluid flush volume. Correlation can be determined using a linear equation that has at least one parameter. One parameter of the at least one parameter may be increased or decreased in accordance with an increase or decrease in the target temperature.

[00094] The target temperature can be configured to minimize a maximum error flow rate for a plurality of pipe types. The tube may be one type of tube from the plurality of tubes.

[00095] The target temperature can be selected to minimize the maximum error flow rate for a plurality of pipe types when using fixed parameters of the at least one parameter of the linear equation.

[00096] The linear equation can be ax+b=y, where x is the delta movement of the plunger, and y is the estimated fluid discharge volume, where the at least one parameter includes a and b of the linear equation.

[00097] Additionally, alternatively or optionally, the heater controller may be configured to activate the heater when a predetermined type of tube is located within the track or may be configured to establish a target temperature based on a set loaded into the track. For example, the heater can be configured to establish a target temperature based on a loaded set. The loaded set can be determined based on user input in the user interface.

[00098] The controller can be coupled to the heater to control the operation of the pump.

[00099] In one embodiment, a method for calibrating a pump uses a pump. The pump includes a plunger and spring configured to urge the plunger toward a tube, a heater configured to thermally transfer heat to the tube, an actuator configured to actuate the plunger away from the tube and against the force of the spring, and a controller. The controller can be configured to control the heating of the heater.

[000100] The method includes the actions of: sealing a volume of fluid within a segment of the tube; allow the spring to compress the tube segment; determining a first position of the plunger when the plunger spring urges the plunger against the tube, and the actuator is not engaged with the plunger; discharging the fluid volume within the tube segment using the plunger by removing the seal from the fluid volume within the tube segment; determining a second position of the plunger after the fluid has discharged the volume of fluid at which the actuator disengages from the plunger to allow the spring to discharge all fluid that can be discharged; determine a delta between the first position and the second position of the piston; correlate the delta to an estimated volume of fluid discharged; and heating a portion of the tube to a target temperature.

[000101] The target temperature of the method can be selected to minimize the difference between the estimated volume of fluid discharged and the actual volume of fluid discharged.

[000102] The method may include the action of measuring the current volume of fluid discharged.

[000103] Actions can be performed repeatedly using a plurality of tube types. Each type of the plurality of tube types can be established by a tube material. The method may include the action of determining the estimated volume of fluid discharged using a linear equation that has at least one parameter during the correlation action. One parameter of the at least one parameter may be increased or decreased in accordance with an increase or decrease in the target temperature.

[000104] The target temperature is set to minimize a maximum error flow rate for a plurality of tube types, wherein the tube is one tube type of the plurality of tubes.

[000105] The target temperature can be selected to minimize the maximum error flow rate for a plurality of pipe types when using fixed parameters at least one parameter of the linear equation. The linear equation of the method can be ax+b=y, where x is the delta movement of the plunger, and y is the estimated fluid discharge volume, where the at least one parameter includes a and b of the linear equation.

[000106] The method may include the action of selecting the target temperature to minimize a difference between the estimated volume of fluid discharge and the volume of fluid discharged during the action of discharging the fluid volume.

[000107] In another embodiment of the present description, it is a method for infusing fluid into a patient, wherein the method includes: peristaltically actuating a tube using a peristaltic pump to pump fluid; periodically press a plunger of the peristaltic pump against the tube; and heating a portion of the tube that is actuated by the plunger.

[000108] A heater may be disposed on the plunger, and the heater may be configured to heat a portion of the tube that is actuated by the plunger. The heater may be disposed on a rear portion of the piston, wherein the rear portion of the piston is on an opposite side of the piston away from the race.

[000109] The peristaltic pump may include a rocker arm coupled to the plunger. The heater may be disposed between the rocker arm and the piston at the rear of the piston.

[000110] The peristaltic pump may also include a temperature sensor (for example, a thermistor) disposed on the piston. The temperature sensor can be configured to measure a temperature of the tube disposed within a raceway, a heater temperature and/or a plunger temperature. The heater may be disposed within a race and is configured to heat the tube retained within the race. The clue may be laid out on the door.

[000111] The method may also include the actions of controlling the heater; and detect the heat generated by the heater.

[000112] The method may perform the action of controlling the heater to reach a target temperature when the pump is programmed to operate beyond a limit flow rate and/or controlling the heater to reach a target temperature when the pump cannot achieve a target flow rate without activating the heater.

[000113] The heater can be activated when a predetermined type of tube is loaded into the raceway. A target temperature can be based on a loaded set (e.g., on the track).

[000114] The loaded set can be determined using user input in a user interface.

[000115] The method may further include: displaying a message to connect a power cable coupled to the pump to a power source in response to activation of the heater; and/or control the operation of the pump by controlling the heating of the heater.

BRIEF DESCRIPTION OF THE DRAWINGS

[000116] These and other aspects will become more apparent from the following detailed description of the various embodiments of the present description with reference to the drawings in which:

[000117] Figure 1 shows a block diagram of a system for infusing liquid in accordance with an embodiment of the present description;

[000118] Figure 2 shows a block diagram of an infusion site monitor of the system of Figure 1 in accordance with an embodiment of the present description;

[000119] Figure 3 shows a block diagram of a pump for infusing the liquid of the system of Figure 1 in accordance with an embodiment of the present description;

[000120] Figure 4 shows a drip chamber retainer that receives a drip chamber and the drip chamber retainer includes a flow meter and a free flow detector in accordance with an embodiment of the present description;

[000121] Figure 5 shows the drip chamber retainer of Figure 4 with an open door in accordance with an embodiment of the present description;

[000122] Figure 6 shows a block diagram of another drip chamber retainer in accordance with another embodiment of the present description;

[000123] Figure 7 shows a ray diagram illustrating the diameter of a blurred circle to illustrate aspects of the drip chamber retainer cameras of Figures 4 and 5 in accordance with an embodiment of the present description;

[000124] Figure 8 is a graph illustrating the blurred circle as calculated for a variety of lens-to-focal plane separations and lens-to-image separations for the drip chamber retainer cameras of Figures 4 and 5 in accordance with an embodiment of the present description;

[000125] Figure 9 is a graph illustrating the blurred circle divided by pixel size when a 20 millimeter focal length lens of the drip chamber retainer cameras of Figures 4 and 5 is used in accordance with an embodiment of the present description;

[000126] Figure 10 is a graph illustrating the blurred circle divided by pixel size when a 40 millimeter focal length lens of the drip chamber retainer cameras of Figures 4 and 5 is used in accordance with an embodiment of the present description;

[000127] Figure 11 shows a table illustrating the corresponding fields of view about the optical geometric axis for the corners of the two configurations of Figures 9 and 10 in accordance with an embodiment of the present description;

[000128] Figure 12 is a block diagram of an imaging system for the drip chamber retainer cameras of Figures 4 and 5 in accordance with an embodiment of the present description;

[000129] Figure 13 is a graphic illustration of an image captured by the camera of the system of Figure 12 in accordance with an embodiment of the present description;

[000130] Figure 14 is a block diagram of an imaging system for the drip chamber retainer cameras of Figures 4 and 5 in accordance with an embodiment of the present description;

[000131] Figure 15 is a graphic illustration of an image captured by the camera of Figure 14 when a free-flow condition exists in accordance with an embodiment of the present description;

[000132] Figure 16 is a graphic illustration of an image captured by the camera of Figure 14 for use as a background image in accordance with an embodiment of the present description;

[000133] Figure 17 is a graphic illustration of an image captured by the camera when droplets are being formed within the dripping chamber of Figure 14 in accordance with an embodiment of the present description;

[000134] Figure 18 is a graphic illustration of an image captured by the camera of Figure 14 for use as a background image in accordance with an embodiment of the present description;

[000135] Figure 19 is a graphic illustration of a difference between the images of Figures 17 and 18 with additional processing in accordance with an embodiment of the present description;

[000136] Figure 20 is a graphical representation of image processing performed using Figures 17 to 19 to determine whether a free flow condition exists in accordance with an embodiment of the present description;

[000137] Figure 21 is a graphic illustration of an image captured by the camera when a free flow condition exists thereby forming a current within the drip chamber of Figure 14 in accordance with an embodiment of the present description;

[000138] Figure 22 is a graphic illustration of an image captured by the camera of Figure 14 for use as a background image in accordance with an embodiment of the present description;

[000139] Figure 23 is a graphic illustration of a difference between the images of Figures 20 and 21 with some additional processing for use in detecting a free flow condition in accordance with an embodiment of the present description;

[000140] Figure 24 is a graphical representation of image processing performed using Figures 21 to 23 to determine whether a free flow condition exists in accordance with an embodiment of the present description;

[000141] Figure 25 illustrates a model for pattern matching to determine whether a free flow condition exists using Figures 17 to 19 or Figures 21 to 23 in accordance with an embodiment of the present description;

[000142] Figure 26 is a graphic illustration of a difference between a reference image and an image containing a vapor processed with edge detection and line detection for use in detecting a free flowing condition in accordance with a embodiment of the present description;

[000143] Figure 27 is a graphic illustration of an image captured by the camera when a free flow condition exists thereby forming a current within the drip chamber of Figure 14 in accordance with an embodiment of the present description;

[000144] Figure 28 is a block diagram of an imaging system for use with the drip chamber retainer of Figures 4 to 5 or Figure 6 that has a striped back pattern and a light source that shines in the stripes. from a location adjacent to a camera in accordance with an embodiment of the present description;

[000145] Figure 29 is a block diagram of an imaging system for use with the drip chamber retainer of Figures 4 to 5 or Figure 6 that has a striped back pattern and a light source that shines in the stripes. behind the rear pattern relative to an end opposite a camera in accordance with an embodiment of the present description;

[000146] Figure 30 shows an image from the camera of Figure 29 when a droplet distorts the back pattern of Figure 26 in accordance with an embodiment of the present description;

[000147] Figure 31 is a block diagram of an imaging system for use with the drip chamber retainer of Figures 4 to 5 or Figure 6 that has a back pattern with a checkerboard pattern and a source of light shining on the stripes behind the posterior pattern relative to an end opposite a camera in accordance with an embodiment of the present description;

[000148] Figure 32 shows an image from the camera of Figure 31 when a droplet distorts the back pattern of Figure 26 in accordance with an embodiment of the present description;

[000149] Figure 33 shows a block diagram of an air detector using a camera in accordance with an embodiment of the present description;

[000150] Figure 34 shows a corresponding model for use in air detection in accordance with an embodiment of the present description;

[000151] Figure 35 illustrates an image captured by the camera of the system of Figure 33 to detect that no tube is within a cavity in accordance with an embodiment of the present description;

[000152] Figure 36 illustrates an image captured by the camera of the system of Figure 33 to detect air bubbles in accordance with an embodiment of the present description;

[000153] Figure 37 illustrates an image captured by the camera of the system of Figure 33 for detecting blood in accordance with an embodiment of the present description;

[000154] Figure 38 illustrates an image of Figure 37 that has undergone image processing to detect a threshold amount of red to detect blood in accordance with an embodiment of the present description;

[000155] Figure 39 shows an infiltration detector in accordance with an embodiment of the present description;

[000156] Figure 40 shows a graph illustrating the optical absorption of oxygenated and deoxygenated hemoglobin in accordance with an embodiment of the present description;

[000157] Figure 41 shows another infiltration detector in accordance with another embodiment of the present description;

[000158] Figure 42 shows a perspective view of an occluder in accordance with an embodiment of the present description;

[000159] Figure 43 shows a side view of the occluder of Figure 42 in accordance with an embodiment of the present description;

[000160] Figure 44 shows a side view of the occluder of Figure 42 in operation in accordance with an embodiment of the present description;

[000161] Figure 45 shows a side view of a valve for use in a cassette in accordance with an embodiment of the present description;

[000162] Figure 46 shows a top view of the valve of Figure 45 in accordance with an embodiment of the present description;

[000163] Figure 47 shows another side view of the valve of Figure 45 installed within a cassette in accordance with an embodiment of the present description;

[000164] Figure 48 shows a slide valve having an inclined plane to provide sealing in accordance with an embodiment of the present description;

[000165] Figure 49 shows a side view of the slide valve of Figure 48 in accordance with an embodiment of the present description;

[000166] Figure 50 shows the assembly of the slide valve of Figures 48 to 49 in accordance with an embodiment of the present description;

[000167] Figures 51 to 55 show a vent for a reservoir in accordance with an embodiment of the present description;

[000168] Figures 56 to 58 illustrate the stages of a flow meter in accordance with an embodiment of the present description;

[000169] Figure 59 shows a diagram of a disposable portion of a flow meter in accordance with an embodiment of the present description;

[000170] Figures 60 to 62 show several views of a disposable portion of a single side of a flow meter in accordance with an embodiment of the present description;

[000171] Figures 63 to 65 show several views of a two-sided disposable portion of a flow meter in accordance with an embodiment of the present description;

[000172] Figures 66 to 68 show several views of the disposable portion of opposite sides with three layers of a flow meter in accordance with an embodiment of the present description;

[000173] Figure 69 shows a top view of another disposable portion of a flow meter in accordance with another embodiment of the present description;

[000174] Figure 70 shows a flow rate meter that includes a complete acoustic volume sensing ("AVS") hinge valve installation and single-sided disposable portion in accordance with an embodiment of the present description;

[000175] Figure 71 shows a side view of the flow rate meter that includes a two-sided AVS installation with integral perimeter sealing valves in accordance with an embodiment of the present description;

[000176] Figure 72 shows a side view of another flow rate meter that includes a single-sided AVS installation with surrounding AVS chambers in accordance with another embodiment of the present description;

[000177] Figure 73 shows a side view of yet another flow rate meter that includes two piston valves in accordance with another embodiment of the present description;

[000178] Figure 74 shows a flow rate meter that has upper and lower AVS mounts that provide a semi-continuous flow in accordance with an embodiment of the present description;

[000179] Figure 75 shows a flow rate meter that has two in-line AVS mounts in accordance with an embodiment of the present description;

[000180] Figure 76 shows a membrane pump that has a negative pressure source in accordance with an embodiment of the present description;

[000181] Figure 77 shows a membrane pump that has negative and positive pressure sources in accordance with an embodiment of the present description;

[000182] Figure 78 shows an optical sensor-based flow rate meter that has two in-line AVS mounts in accordance with an embodiment of the present description;

[000183] Figure 79 shows a pressure-controlled membrane pump in accordance with an embodiment of the present description;

[000184] Figures 80 to 82 show a diagram of a legend for use in conjunction with Figures 79 and 83 to 98 in accordance with an embodiment of the present description;

[000185] Figure 83 shows a flow-controlled membrane pump in accordance with an embodiment of the present description;

[000186] Figure 84 shows a state diagram of the operation of the flow-controlled membrane pump of Figure 83 in accordance with an embodiment of the present description;

[000187] Figure 85 shows the flow-controlled membrane pump of Figure 83 which illustrates the operation of the valves when in the idle state of the state diagram of Figure 84 in accordance with an embodiment of the present description;

[000188] Figure 86 shows a more detailed view of the idle state of the state diagram of Figure 84 in accordance with an embodiment of the present description;

[000189] Figures 87 to 88 show the flow-controlled membrane pump of Figure 83 in use during the positive pressure valve leak test state of Figure 84 in accordance with an embodiment of the present description;

[000190] Figure 89 shows a more detailed view of the positive pressure valve leak test state of Figure 84 in accordance with an embodiment of the present description;

[000191] Figures 90 to 91 show the flow-controlled membrane pump of Figure 83 in use during the negative pressure valve leak test state of Figure 84 in accordance with an embodiment of the present description;

[000192] Figure 92 shows a more detailed view of the negative pressure valve leak test state of Figure 84 in accordance with an embodiment of the present description;

[000193] Figure 93 shows the flow-controlled membrane pump of Figure 83 in use during the filling state of Figure 84 in accordance with an embodiment of the present description;

[000194] Figure 94 shows a more detailed view of the filling state of Figure 84 in accordance with an embodiment of the present description;

[000195] Figure 95 shows the flow-controlled membrane pump of Figure 83 in use during an AVS measurement in accordance with an embodiment of the present description;

[000196] Figure 96 shows a more detailed view of the AVS measurement state of Figure 84 in accordance with an embodiment of the present description;

[000197] Figure 97 shows the flow-controlled membrane pump of Figure 83 in use during the emptying state of Figure 84 in accordance with an embodiment of the present description;

[000198] Figure 98 shows a more detailed view of the emptying state of Figure 84 in accordance with an embodiment of the present description;

[000199] Figure 99 shows a membrane pump that has an elastic membrane that is flush with a disposable portion and applies a force to a liquid in accordance with an embodiment of the present description;

[000200] Figures 100 to 101 show two modalities of lung pumps in accordance with the modalities of the present description;

[000201] Figures 102 to 104 show various gaskets for sealing a lung-type pump in accordance with additional embodiments of the present description;

[000202] Figure 105 shows another lung-type pump in accordance with another embodiment of the present description;

[000203] Figures 106 to 112 illustrate the operation of a piston pump while performing various checks in accordance with an embodiment of the present description;

[000204] Figures 113 and 114 illustrate a piston pump in accordance with another embodiment of the present description;

[000205] Figures 115 and 116 show two views of a cassette having several membrane pumps of Figures 113 and 114 in accordance with an embodiment of the present description;

[000206] Figure 117 shows a cassette having a membrane pump and volcano-type valves in accordance with an embodiment of the present description;

[000207] Figure 118 shows a roller mechanism of a cassette-based pump in accordance with an embodiment of the present description;

[000208] Figure 119 shows the fluid paths of a cassette-based pump for use with the roller mechanism of Figure 118 in accordance with an embodiment of the present description;

[000209] Figure 120 shows the fluid paths of a cassette-based pump for use with the roller mechanism of Figure 118 in accordance with an embodiment of the present description;

[000210] Figure 121 shows the stages of an infiltration test using a roller in accordance with an embodiment of the present description;

[000211] Figure 122 shows the stages of an infiltration test using a piston in accordance with an embodiment of the present description;

[000212] Figures 123 and 124 show a cell-based reservoir in accordance with an embodiment of the present description;

[000213] Figures 125 and 126 show a tube-based reservoir in accordance with an embodiment of the present description;

[000214] Figure 127 shows several stages illustrating a method for operating a plunger pump in conjunction with an AVS installation in accordance with an embodiment of the present description;

[000215] Figure 128 shows several stages illustrating a method for operating a plunger pump in conjunction with an AVS installation in accordance with another embodiment of the present description;

[000216] Figure 129 shows several stages illustrating a method for using a plunger pump having an AVS installation in accordance with an embodiment of the present description;

[000217] Figure 130 shows several stages illustrating a method for using a plunger pump having an AVS installation in accordance with an embodiment of the present description;

[000218] Figure 131 shows several stages illustrating a method for using a plunger pump having an AVS installation in accordance with an embodiment of the present description;

[000219] Figure 132 shows a plunger pump with an actuator within the variable volume for use with standard set IV tubing in accordance with an embodiment of the present description;

[000220] Figure 133 shows several views of a cam-driven linear peristaltic pump having diaphragm valves and a plunger within a variable volume in accordance with an embodiment of the present description;

[000221] Figure 134 shows a plunger pump for use with standard IV set tubing with a variable volume off actuator in accordance with an embodiment of the present description;

[000222] Figure 135 shows several views of a cam-driven linear peristaltic pump having diaphragm valves and a plunger within a variable volume with a corresponding cam mechanism outside the variable volume in accordance with an embodiment of the present description;

[000223] Figure 136 shows a plunger pump having a plunger within a variable volume with an actuator outside the variable volume in accordance with an embodiment of the present description;

[000224] Figure 137 shows a cam-driven linear peristaltic pump having a plunger within a variable volume with a corresponding cam mechanism outside the variable volume and diaphragm valves in the variable volume housing in accordance with an embodiment of the present description ;

[000225] Figure 138 shows a plunger pump having a plunger within a variable volume and diaphragm valves outside the variable volume in accordance with an embodiment of the present description;

[000226] Figure 139 shows several views of a cam-driven linear peristaltic pump having a plunger within a variable volume with a corresponding cam mechanism and diaphragm valves outside the variable volume in accordance with an embodiment of the present description;

[000227] Figure 140 illustrates occlusion detection using a plunger pump having an AVS installation and a spring-driven diaphragm mechanism within the variable volume in accordance with an embodiment of the present description;

[000228] Figure 141 shows a pump with a spring-loaded plunger within a variable volume of an AVS installation with a plunger actuated outside the variable volume in accordance with an embodiment of the present description;

[000229] Figure 142 shows a linear peristaltic pump with diaphragm valves and a cam shaft disposed within a variable volume of an AVS installation having the spring-driven diaphragm mechanism disposed therein and a plunger and a diaphragm valve outside the variable volume in accordance with an embodiment of the present description;

[000230] Figure 143 shows a linear peristaltic pump with diaphragm valves and a plunger disposed outside a variable volume of an AVS installation in accordance with an embodiment of the present description;

[000231] Figure 144 shows the stages of a plunger pump having a camera or optical sensor for measuring the volume within a tube residing within a chamber in accordance with an embodiment of the present description;

[000232] Figure 145 shows a plunger pump that has a chamber that has an optical sensor for estimating the fluid volume of a tube that has a spring-driven diaphragm mechanism around the tube and a plunger and diaphragm valves in agreement with an embodiment of the present description;

[000233] Figure 146 shows a plunger pump that has a chamber with an optical sensor for estimating fluid volume from a tube that has a spring-driven diaphragm mechanism around the tube and a plunger and diaphragm valves outside the chamber in accordance with an embodiment of the present description;

[000234] Figure 147 shows several views of a plunger pump having an AVS installation with a diaphragm valve disposed within the volume of the AVS installation and a plunger and a diaphragm valve arranged outside the variable volume in accordance with an embodiment of the present description;

[000235] Figure 148 shows two cross-sectional views of the plunger pump of Figure 147 in accordance with an embodiment of the present description;

[000236] Figure 149 shows two alternative cross-sectional views of the plunger pump of Figure 147 in accordance with an embodiment of the present description;

[000237] Figure 150 illustrates the stages during normal operation of a plunger pump having a spring-driven plunger in accordance with an embodiment of the present description;

[000238] Figure 151 illustrates the stages for detecting an occlusion for a plunger pump having a spring-driven plunger in accordance with an embodiment of the present disclosure;

[000239] Figure 152 illustrates the stages for leak detection for a plunger pump having a spring-driven plunger in accordance with an embodiment of the present description;

[000240] Figure 153 illustrates the stages for detecting a bubble and/or failed valve detection for a plunger pump having a spring-driven plunger in accordance with an embodiment of the present description;

[000241] Figure 154 illustrates the stages for empty reservoir detection and/or upstream occlusion detection for a plunger pump having a spring-driven plunger in accordance with an embodiment of the present description;

[000242] Figure 155 illustrates the stages for preventing free flow for a plunger pump having a spring-driven plunger in accordance with an embodiment of the present description;

[000243] Figure 156 illustrates the stages for checking a negative pressure valve for a plunger pump having a spring-driven plunger in accordance with an embodiment of the present description;

[000244] Figures 157 to 158 show views of a plunger pump having a cam shaft 671 traversing the variable volume of an AVS installation in accordance with an embodiment of the present description;

[000245] Figures 159 to 162 illustrate various cam profiles in accordance with various embodiments of the present description;

[000246] Figure 163 illustrates a peristaltic pump having a plunger and a diaphragm valve outside an AVS chamber with two diaphragm valves at the ACS chamber interface in accordance with an embodiment of the present description;

[000247] Figure 164 illustrates various stages of the operation of the peristaltic pump of Figure 163 in accordance with an embodiment of the present description;

[000248] Figure 165 illustrates a peristaltic pump that has two pistons external to an AVS chamber in accordance with an embodiment of the present description;

[000249] Figure 166 illustrates various stages of the peristaltic pump of Figure 165 in accordance with an embodiment of the present description;

[000250] Figure 167 illustrates a peristaltic pump that has a plunger with a linear sensor in accordance with an embodiment of the present description;

[000251] Figure 168 illustrates a data graph from the linear sensor of the peristaltic pump of Figure 167 in accordance with an embodiment of the present description;

[000252] Figure 169 illustrates the stages of the peristaltic pump of Figure 169 in accordance with an embodiment of the present description;

[000253] Figure 170 illustrates the detection of an occlusion condition compared to a non-occluded condition in accordance with an embodiment of the present description;

[000254] Figure 171 illustrates the detection of a valve leak compared to a complete valve seal condition in accordance with an embodiment of the present description;

[000255] Figure 172 illustrates the detection of too much air in the tube or a valve failure compared to an appropriate operation in accordance with an embodiment of the present description;

[000256] Figure 173 shows a block diagram illustrating the electronics of a peristaltic pump in accordance with another embodiment of the present description;

[000257] Figure 174 shows a block diagram illustrating the electronics of a peristaltic pump in accordance with another embodiment of the present description;

[000258] Figure 175 shows a perspective view of the peristaltic pump in accordance with an embodiment of the present description;

[000259] Figures 176 to 180 show data from the various AVS scans in accordance with an embodiment of the present description;

[000260] Figures 181 to 183 show several side views of a cam mechanism of the peristaltic pump of Figure 175 in accordance with an embodiment of the present description;

[000261] Figure 184 shows a sectional view of the diaphragm and plunger valves of the peristaltic pump of Figure 175 in accordance with an embodiment of the present description;

[000262] Figure 185 shows two views of a plunger with flexible fingers for gripping a tube in accordance with an embodiment of the present description;

[000263] Figure 186 shows an embodiment of a cam mechanism of a peristaltic pump in accordance with an embodiment of the present description;

[000264] Figure 187 shows an embodiment of a cam mechanism of a peristaltic pump in accordance with an embodiment of the present description;

[000265] Figures 188 to 190 show several views of a peristaltic pump in accordance with the present description;

[000266] Figures 191 to 195 show several views of a peristaltic pump in accordance with an additional embodiment of the present description;

[000267] Figures 196A to 196B illustrate the torque on a cam shaft of a peristaltic pump in accordance with an embodiment of the present description;

[000268] Figure 197 illustrates a cam profile for several cams for a peristaltic pump in accordance with an embodiment of the present description;

[000269] Figure 198 shows various feedback modes of a peristaltic pump in accordance with an embodiment of the present description;

[000270] Figure 199 shows a graph illustrating data from a linear sensor used to estimate fluid flow in accordance with an embodiment of the present description;

[000271] Figures 200 to 206 show several perspective views of a peristaltic pump having an angular member that interfaces with a cam in accordance with an embodiment of the present description;

[000272] Figures 207 to 221 illustrate the operation of a slide occluder of the peristaltic pump of Figures 200 to 206 in accordance with an embodiment of the present description;

[000273] Figures 222 to 223 show two views of a peristaltic pump in accordance with an embodiment of the present description;

[000274] Figures 224 to 238 show various views of the peristaltic pump of Figures 222 to 223 that illustrate the operation of the slide occluder in accordance with an embodiment of the present description;

[000275] Figures 239 to 245 show various views of the peristaltic pump of Figures 222 to 238 in accordance with an embodiment of the present description;

[000276] Figures 246 to 250 show several views of an integrated motor and cam for use in a peristaltic pump described in the present document in accordance with another embodiment of the present description;

[000277] Figures 251 to 254 illustrate a camera sensor for use in measuring the position of a plunger and diaphragm valves of a peristaltic pump in accordance with an embodiment of the present description;

[000278] Figure 255 illustrates a peristaltic pump that has L-shaped cam followers in an exploded view of the mechanical elements of the top of the pump in accordance with an embodiment of the present description;

[000279] Figure 256 illustrates the peristaltic pump having L-shaped cam followers in an exploded view of the mechanical elements of the bottom of the pump in accordance with an embodiment of the present description;

[000280] Figure 257 illustrates the peristaltic pump having L-shaped cam followers with an open door in an isometric view of the mechanical elements of the top of the pump in accordance with an embodiment of the present description;

[000281] Figure 258 illustrates the peristaltic pump having L-shaped cam followers in an exploded view showing the PCB, pump body, port and a motor with a gear head in accordance with an embodiment of the present description;

[000282] Figure 259 illustrates the slide occluder inserted into the open port of the peristaltic pump having L-shaped cam followers in accordance with an embodiment of the present description;

[000283] Figure 260 illustrates the peristaltic pump having L-shaped cam followers with the door open and some elements removed to reveal the cam shaft, pump and valves in accordance with an embodiment of the present description;

[000284] Figure 261 illustrates the insertion of the slide occluder into the open port of the peristaltic pump having L-shaped cam followers in accordance with an embodiment of the present description;

[000285] Figures 262 to 263 show an alternative door with the door half of an alternative split conveyor in accordance with an embodiment of the present description;

[000286] Figure 264 illustrates the door, a lever and a slide conveyor of the peristaltic pump having L-shaped cam followers in an exploded view in accordance with an embodiment of the present description;

[000287] Figure 265 illustrates the peristaltic pump having L-shaped cam followers with an open door in an isometric view of the mechanical elements of the bottom of the pump in accordance with an embodiment of the present description;

[000288] Figure 266 illustrates the cam shaft of the peristaltic pump having L-shaped cam followers in an isometric view in accordance with an embodiment of the present description;

[000289] Figure 267 illustrates the piston cam follower of the peristaltic pump having L-shaped cam followers in an isometric view from the front in accordance with an embodiment of the present description;

[000290] Figure 268 illustrates the peristaltic pump plunger cam follower having L-shaped cam followers in an isometric view from behind in accordance with an embodiment of the present description;

[000291] Figure 269 illustrates the piston cam follower of the peristaltic pump having L-shaped cam followers in an isometric view of a first side in accordance with an embodiment of the present description;

[000292] Figure 270 illustrates the piston cam follower of the peristaltic pump having L-shaped cam followers in an isometric view from a second side in accordance with an embodiment of the present description;

[000293] Figure 271 illustrates the peristaltic pump outlet cam having L-shaped cam followers in an orthographic view in accordance with an embodiment of the present description;

[000294] Figure 272 illustrates the pump cam of the peristaltic pump having L-shaped cam followers in an orthographic view in accordance with an embodiment of the present description;

[000295] Figure 273 illustrates the inlet cam of the peristaltic pump having L-shaped cam followers in an orthographic view in accordance with an embodiment of the present description;

[000296] Figure 274 illustrates the plunger and valve cam followers of the peristaltic pump having L-shaped cam followers in an exploded view in accordance with an embodiment of the present description;

[000297] Figure 275 illustrates the spring retainers on the cam followers of the peristaltic pump having L-shaped cam followers in an isometric view in accordance with an embodiment of the present description;

[000298] Figure 276 shows a cross-section of the pump including sections of the cam, plunger and plate in accordance with an embodiment of the present description;

[000299] Figure 277 shows a cross-sectional view of the plunger that compresses the infusion tube against the plate in accordance with an embodiment of the present description;

[000300] Figure 278 illustrates the housing, cam shaft and cam followers of the peristaltic pump having L-shaped cam followers in an exploded view in accordance with an embodiment of the present description;

[000301] Figure 279 illustrates the upper and lower housing of the peristaltic pump having L-shaped cam followers in an isometric view in accordance with an embodiment of the present description;

[000302] Figure 280 illustrates the installed upper and lower housing of the peristaltic pump having L-shaped cam followers in isometric views in accordance with an embodiment of the present description;

[000303] Figure 281 illustrates the installed upper and lower housing of the peristaltic pump having L-shaped cam followers in isometric views in accordance with an embodiment of the present description;

[000304] Figure 282 illustrates the peristaltic pump having L-shaped cam followers with PCB removed to reveal magnets on the plunger and corresponding sensors on the PCB in accordance with an embodiment of the present description;

[000305] Figure 283 illustrates the insertion of the slide occluder into the open opening of the peristaltic pump having L-shaped cam followers in accordance with an embodiment of the present description;

[000306] Figure 284 illustrates the slide occluder inserted into the open port of the peristaltic pump having L-shaped cam followers in accordance with an embodiment of the present description;

[000307] Figures 285 illustrate the broken conveyor in the open position in accordance with an embodiment of the present description;

[000308] Figures 286 illustrate the broken conveyor in the closed position in accordance with an embodiment of the present description;

[000309] Figure 287 illustrates the peristaltic pump having L-shaped cam followers with the door partially closed and some elements removed to reveal the slide occluder on the closed broken conveyor in accordance with an embodiment of the present description;

[000310] Figure 288 illustrates the multi-part connection between the broken carrier and the lever in an isometric view in accordance with an embodiment of the present description;

[000311] Figure 289 illustrates the peristaltic pump having L-shaped cam followers with the door closed and some elements removed to reveal the slide occluder on the closed split conveyor in accordance with an embodiment of the present description;

[000312] Figures 290 to 293 illustrate four steps of closing the ports of the peristaltic pump having L-shaped cam followers in accordance with an embodiment of the present description;

[000313] Figure 294 illustrates a lever in the port that engages a pin in the body of the peristaltic pump that has L-shaped cam followers in accordance with an embodiment of the present description;

[000314] Figure 295 illustrates a spring element in the port of the peristaltic pump that has L-shaped cam followers in accordance with an embodiment of the present description;

[000315] Figure 296 illustrates two lever locking hooks on the port of the peristaltic pump having L-shaped cam followers in accordance with an embodiment of the present description;

[000316] Figure 297 shows a vertical cross-sectional view of the peristaltic pump with L-shaped cam followers in accordance with an embodiment of the present description;

[000317] Figure 298 shows a horizontal cross-sectional view of the peristaltic pump with L-shaped cam followers in accordance with an embodiment of the present description;

[000318] Figure 299 illustrates a spring pin that engages a detent on the lever lock hook in the closed position within the door of the peristaltic pump having L-shaped cam followers in accordance with an embodiment of the present description;

[000319] Figure 300 illustrates a spring pin that engages a detent on the lever lock hook in the open position within the port of the peristaltic pump having L-shaped cam followers in accordance with an embodiment of the present description;

[000320] Figure 301 illustrates a sliding occluder detection lever displaced by the sliding occluder when the port is on the peristaltic pump having L-shaped cam followers in accordance with an embodiment of the present description;

[000321] Figure 302 illustrates a latch hook detection lever displaced by the latch hook when the port is on the peristaltic pump having L-shaped cam followers in accordance with an embodiment of the present description;

[000322] Figures 303 to 306 show several views of a patient bed system in accordance with an embodiment of the present description;

[000323] Figure 307 shows a close-up view of a portion of an interface of a claw that is attachable to a pump shown in Figures 303 to 306 in accordance with an embodiment of the present description;

[000324] Figure 308 shows another approximate view of another portion of the interface shown in Figure 301 in accordance with an embodiment of the present description;

[000325] Figure 309 shows a perspective view of a pump shown in Figures 303 to 306 in accordance with an embodiment of the present description;

[000326] Figure 310 shows a perspective view of a pump shown in Figures 303 to 306 in accordance with an embodiment of the present description;

[000327] Figure 311 shows a perspective view of a pump with the graphical user interface shown on the screen in accordance with an embodiment of the present description;

[000328] Figure 312 shows an exemplary infusion programming screen of the graphical user interface in accordance with an embodiment of the present description;

[000329] Figure 313 shows an exemplary infusion programming screen of the graphical user interface in accordance with an embodiment of the present description;

[000330] Figure 314 shows an exemplary infusion programming screen of the graphical user interface in accordance with an embodiment of the present description;

[000331] Figure 315 shows an exemplary infusion programming screen of the graphical user interface in accordance with an embodiment of the present description;

[000332] Figure 316 shows an exemplary infusion programming screen of the graphical user interface in accordance with an embodiment of the present description;

[000333] Figure 317 shows an infusion rate over time graphical representation of an exemplary infusion in accordance with an embodiment of the present description;

[000334] Figure 318 shows an infusion rate over time graphical representation of an exemplary infusion in accordance with an embodiment of the present description;

[000335] Figure 319 shows an infusion rate over time graphical representation of an exemplary infusion in accordance with an embodiment of the present description;

[000336] Figure 320 shows an infusion rate over time graphical representation of an exemplary infusion in accordance with an embodiment of the present description;

[000337] Figure 321 shows an infusion rate over time graphical representation of an exemplary infusion in accordance with an embodiment of the present description;

[000338] Figure 322 shows an exemplary drug administration library screen of the graphical user interface in accordance with an embodiment of the present description;

[000339] Figure 323 shows a schematic of a battery-powered suction speaker in accordance with an embodiment of the present description;

[000340] Figure 324 illustrates an electrical block diagram of the peristaltic pump in accordance with an embodiment of the present description;

[000341] Figures 325A to 325G illustrate a detailed electrical block diagram of the peristaltic pump in accordance with an embodiment of the present description;

[000342] Figure 326 shows a linear encoder signal along the cam angle graph in accordance with an embodiment of the present description;

[000343] Figure 327 illustrates a volume along the time graph in accordance with an embodiment of the present description;

[000344] Figure 328 illustrates a cam axis angle along the volume graph in accordance with an embodiment of the present description;

[000345] Figure 329 illustrates a possible measured pressure versus time tracking of a delivery line downstream of the peristaltic pump in accordance with an embodiment of the present description;

[000346] Figure 330 is a state diagram in accordance with an embodiment of the present description;

[000347] Figure 331 is a software block diagram in accordance with an embodiment of the present description;

[000348] Figure 332 is a software block diagram in accordance with an embodiment of the present description;

[000349] Figure 333 shows a feedback-based control cycle for controlling an infusion pump motor in accordance with an embodiment of the present description;

[000350] Figure 334 shows a process diagram for illustrating the software operation of an infusion pump in accordance with an embodiment of the present description;

[000351] Figures 335 to 336 show two dual-band antennas for use with an infusion pump in accordance with an embodiment of the present description.

[000352] Figure 337 shows a state diagram illustrating a method for providing a surveillance functionality in accordance with an embodiment of the present description;

[000353] Figures 338A to 338F show a circuit diagram of a surveillance system that is an embodiment that implements the surveillance functionality of the state diagram of Figure 337 in accordance with another embodiment of the present description;

[000354] Figure 339 shows another embodiment of the peristaltic pump that has an L-shaped plunger in accordance with an embodiment of the present description;

[000355] Figure 340 shows an exploded view of the peristaltic pump of Figure 339 in accordance with an embodiment of the present description;

[000356] Figure 341 shows a close-up view of the upper housing, the lower housing and the power supply of the peristaltic pump of Figure 339 in accordance with an embodiment of the present description;

[000357] Figure 342A shows a front view of the pump display of Figure 339 in accordance with an embodiment of the present description;

[000358] Figure 342B shows a rear view of the pump display of Figure 339 in accordance with an embodiment of the present description;

[000359] Figure 343 shows the rear of the touch screen sensor portion and a frame-based split ring resonator for use with a near-field antenna in accordance with an embodiment of the present description;

[000360] Figure 344 shows an approximate side view of the pump of Figure 339 which shows a rotation sensor for measuring the rotation of the cam shaft in accordance with an embodiment of the present description;

[000361] Figure 345 shows an approximate side view of the pump of Figure 339 with a cut plane in accordance with an embodiment of the present description;

[000362] Figure 346 shows a diagram illustrating the use of the pump sensors of Figure 399 when one or more of the sensors are unavailable in accordance with an embodiment of the present description;

[000363] Figures 347 to 350 show the operation of the pump door latch of Figure 399 in accordance with an embodiment of the present description;

[000364] Figure 351 shows an optical sensor for estimating parameters of a fluid line in accordance with an embodiment of the present description;

[000365] Figure 352 shows an optical sensor of Figure 351 with a fluid line in accordance with an embodiment of the present description;

[000366] Figure 353 shows an optical layer sensor for estimating parameters of a fluid line in accordance with an embodiment of the present description;

[000367] Figures 354 to 355 show the operation of a tube restoration apparatus in accordance with an embodiment of the present description;

[000368] Figures 356 to 357 show the operation of a tube restoration apparatus in accordance with an embodiment of the present description;

[000369] Figure 358 shows a circuit for storing data within an RFID tag associated with an infusion pump in accordance with an embodiment of the present description;

[000370] Figure 359 shows an equivalent circuit for impedance as seen from the RFID tag of Figure 358 in accordance with an embodiment of the present description;

[000371] Figure 360 shows another circuit for storing data within an RFID tag associated with an infusion pump in accordance with an embodiment of the present description; It is

[000372] Figure 361 shows a split ring resonator used with the circuit of Figure 360 in accordance with an embodiment of the present description;

[000373] Figure 362 shows an L-shaped cam follower having a heater for engagement with an IV tube in accordance with an embodiment of the present description; It is

[000374] Figure 363 shows a block diagram of a system for controlling a peristaltic pump having a heater in accordance with an embodiment of the present description;

[000375] Figure 364 shows a flow chart illustrating a method 4500 for infusing fluid into a patient in accordance with an embodiment of the present description; It is

[000376] Figures 365A and 365B show a flowchart of a method 4516 for calibrating a pump in accordance with an embodiment of the present description.

DETAILED DESCRIPTION

[000377] Figure 1 shows a block diagram of a system 1 for infusing fluid. System 1 includes fluid reservoirs 2, 3 and 4 for infusing the fluid contained therein to a patient 5. Fluid reservoirs 2, 3 and 4 are gravity fed into drip chambers 7, 8 and 9, respectively. Drip chambers 7, 8 and 8 are fed respectively to flow meters 10, 11 and 12. From flow meters 10, 11 and 12, fluid is fed to free flow detectors 13, 14 and 15, respectively.

[000378] System 1 also includes valves 16, 17 and 18 of a respective free flow detector of free flow detectors 13, 14 and 15. Pumps 19, 20 and 21 receive fluid from valves 16, 17 and 18 and combine the fluid using a connector 22. Valves 16, 17 and 18 may be in wireless or wired communication with a respective pump 19, 20 and 21 to control the flow rate and/or discharge profile. For example, the pump 19 may wirelessly communicate with the valve 16 to adjust the opening and closing of the valve 16 to achieve a target flow rate, for example, when the pump 19 operates at a predetermined speed; valves 16 may be downstream of pump 19 in some embodiments.

[000379] Fluid from connector 22 is fed to an occlusion detector 23 which is fed to an air detector 24. The occlusion detector 23 can detect when an occlusion exists within the system piping 1. The occlusion detector 23 can be a pressure sensor compressed against the tube so that an increase beyond a predetermined threshold is indicative of an occlusion. The air detector 24 detects whether air is present in the tubing, for example, when flowing toward the patient 5. Before entering an infusion site monitor 26, the fluid passes through a valve 25.

[000380] The monitoring client 6, in some embodiments, monitors the operation of the system 1. For example, when an occlusion is detected by the occlusion detector 23 and/or air is detected by the air detector 24, the monitoring client 6 may wirelessly communicate a signal to the valve 25 to retain the flow of fluid to the patient 5.

[000381] Monitoring client 6 can also remotely send a prescription to a pharmacy. The prescription may be a prescription to infuse a fluid with the use of a fluid pump. The pharmacy may include one or more computers connected to a network (e.g., the internet) to receive the prescription and queue the prescription within the one or more computers. The pharmacy may use the prescription to compound the drug (for example, with the use of an automatic compounding device coupled to one or more computers or manually by a pharmacist viewing the queue of the one or more computers), prefill a reservoir of fluid associated with an infusion pump and/or programming the infusion pump (e.g., a treatment regimen is programmed for the infusion pump 19) at the pharmacy in accordance with the prescription. The fluid reservoir 2 may be automatically filled by the automatic compounding device and/or the infusion pump 19 may be automatically programmed by the automatic compounding device. The automatic compounding device may generate a barcode, the RFID beacon 29 and/or data. Information within the barcode, RFID 29 beacon and/or data may include treatment regimen, prescription and/or patient information. The automatic compounding device may: attach the barcode to the fluid reservoir 2 and/or the infusion pump 19; attach the RFID beacon 29 to the fluid reservoir 2 and/or the infusion pump 19; and/or programming the RFID beacon 29 or the memory within the fluid reservoir 2 or infusion pump 19 with the information or data. The data or information may be sent to a database (e.g., electronic medical records) that associates the prescription with the fluid reservoir 2 and/or infusion pump 19, for example, using a serial number or other identifying information within the barcode, RFID 29 beacon or memory.

[000382] The infusion pump 19 may have a digitizer, for example, an RFID interrogator that interrogates the RFID beacon 29 or a barcode scanner that scans a barcode from the fluid reservoir 2, to determine which fluid is correct fluid reservoir 2 is the correct fluid reservoir 2, the treatment programmed into the infusion pump 19 corresponds to the fluid within the fluid reservoir 2 and/or the fluid reservoir 2 and the infusion pump 19 are correct for the particular patient (e.g., as determined from a patient barcode, RFID 27, or other patient identification). For example, the infusion pump 19 may scan the RFID beacon 29 of the fluid reservoir 2 and verify that the serial number or fluid type encoded within the RFID beacon 29 is the same as indicated by the treatment programmed within the infusion pump 19. Additionally or alternatively, the infusion pump 19 may interrogate the RFID beacon 29 of fluid reservoir 2 for a serial number and the RFID beacon 27 of patient 5 for a patient serial number and also interrogate electronic medical records to determine whether the serial number of the fluid reservoir 19 within the RFID beacon 29 matches the patient's serial number within the RFID beacon 27 as indicated by the electronic medical records. Additionally or alternatively, the monitoring client 6 may scan the RFID beacon 29 of the fluid reservoir 2 and an RFID beacon of the infusion pump 19 to determine which is the correct fluid within the fluid reservoir 2, is the correct fluid reservoir 2, The treatment programmed into the infusion pump 19 corresponds to the fluid within the fluid reservoir 2 and/or the fluid reservoir 2 and the infusion pump 19 are correct for the particular patient (e.g., as determined from a barcode identification, RFID 27 beacon, electronic medical records or other patient information or identification). Additionally or alternatively, the monitoring client 6 or infusion pump 19 may interrogate an electronic medical record database and/or the pharmacy to verify the prescription or download the prescription, for example, with the use of a number. bar code serial number on infusion pump 19 or fluid reservoir 2.

[000383] Additionally or alternatively, the flow of pumps 19, 20 and 21 can be monitored and/or controlled by monitoring client 6 to ensure safe drug delivery. The monitoring client 6 can scan an RFID beacon 27 on a bracelet 28 and also RFID beacons 29, 30 and 31 on fluid reservoirs 2, 3 and 4, respectively. The monitoring client 6 may download the electronic medical records ("EMR") associated with the RFID beacon 27 on the bracelet of the patient 5 and compare it to one or more prescriptions found in the EMR of the patient 5. If the EMR indicates that the fluid reservoirs 2, 3 and 4 contain the correct medication, a user can enter into the monitoring client 6 a command to start pumping fluid through pumps 19, 20 and/or 21 to patient 5.

[000384] Infusion site monitor 26 monitors the site at which fluid is fed to patient 5. Infusion site monitor 26 receives fluid through an inlet port 408 and feeds fluid to patient 5 through of an outlet port 409. As shown in Figure 2, in some embodiments, the infusion site monitor 5 optionally includes an air detector 410, an infiltration detector 32, a pressure sensor 33, a fluid temperature sensor 34 and/or a patient temperature sensor 35. In some embodiments, the infusion site monitor 26 optionally includes an ambient air temperature sensor 35 and an RFID interrogator 41A.

[000385] Infusion site monitor 26 also includes a processor 37 and memory 38. Memory 38 may include processor-executable instructions configured to execute on processor 37. Processor 37 is in functional communication with air detector 410 , the infiltration detector 32, the pressure sensor 33, the fluid temperature sensor, the patient temperature sensor 35, the ambient air temperature sensor 36, the RFID interrogator 41A, the user input 39 and the buttons 40; for example, the processor 37 may be coupled to a bus, a parallel communication link, a serial communication link, a wireless communication link, and the like. Referring to Figures 1 and 2, information from the various circuit sets 410, 32, 33, 34, 35, 36, 39, 40 and/or 41 may be communicated to the monitoring client 6 via a data link. wired or wireless communication, for example, WiFi, USB, serial, WIMAX ®, BLUETOOTH ®, ZIGBEE ® and the like.

[000386] In Figure 1, each of the pumps 19, 20 and 21 or the fluid reservoirs 2, 3 and 4 may include an upstream and/or downstream pressure generation source (for example, an occluder, high - speaker, etc.) to generate a pressure "signature" that would travel along the pipe and to the other devices, e.g. pumping, monitoring or measuring devices. These pressure signatures may indicate the pressure in each of the tubes, may be used to identify each tube and coordinate the tubes' flow rates, and/or may indicate what the tube's measured flow rate should be. The pressure signature may be an ultrasonic signal generated by a piezoelectric ceramic that is modulated to encode information such as digital data or analog signal, for example, an acoustic carrier frequency with FM modulation, AM modulation, digital modulation, analog modulation or similar.

[000387] For example, each of the pumps 19, 20 and 21 may transmit sound pressure down the IV tube to the infusion site monitor 26 (which may include a transducer for detecting these pressure waves) indicating to the infusion monitor 26 infusion site 26 the expected total flow rate through them. A flow rate meter 169 (see Figure 2) may measure the net flow rate and if the measured net flow rate deviates by a predetermined amount, the infusion site monitor 26 may issue an alarm and/or alert. for example, the alarm may signal valves 16, 17, 18 and 25 to close and/or the monitoring client 6 may use the information for logging purposes and/or to cause valves 16, 17, 18 and 25 to close. close.

[000388] Referring again to Figure 2 and as mentioned previously, the processor 37 is in functional communication with the user input 39 and one or more buttons 40. The infusion site monitor 26 can receive various user inputs 39 to signal the processor 37 to begin monitoring treatment of patient 5. Additionally or alternatively, the infusion site monitor 26 may interrogate the RFID 27 of the patient's bracelet 5 (see Figure 1) to determine whether the infusion site monitor 26 is coupled to the correct patient 5.

[000389] The air detector 410 is in functional communication with the processor 37. The air detector 410 can measure, estimate and/or determine the amount of air entering the infusion site monitor 26 through the inlet port 29 In some embodiments, when the processor 37 determines that the air within the pipe exceeds a predetermined threshold, the processor 37 communicates an alarm or alert to the monitoring client 6 (see Figure 1) which may signal the valve 25 to stop the flow. of fluid to the patient 5. Additionally or alternatively, the processor 37 may communicate an alarm or alert to valve 25 or to one or more of pumps 19, 20 and 21 to stop the flow of fluid when the air within the tube exceeds the predetermined threshold. The air detector 410 may be an ultrasonic air detector, an impedance-based air detector, and the like.

[000390] The infiltration detector 32 is in functional communication with the processor 37. The infiltration detector 32 can measure, estimate and/or determine the amount of blood entering the infusion site monitor 26 through the exit port 30 during an infiltration test. In some embodiments, when the processor 37 determines that the blood within the tube is less than a predetermined threshold during an infiltration test, the processor 37 communicates an alarm or alert to the monitoring client 6 (see Figure 1) that may signal the valve 25 to stop the flow of fluid to the patient 5. Additionally or alternatively, the processor 37 may communicate an alarm or alert to the valve 25 or to one or more of the pumps 19, 20 and 21 to stop the flow of fluid. fluid when infiltration tests determine that a infiltration has occurred. The infiltration test may include reversing one or more of the pumps 19, 20 and/or 21 to determine whether blood flows to the infusion site monitor 26. When an infiltration has occurred, blood will not flow easily to the infusion site monitor. infusion tube 26. Thus, when fluid is extracted from patient 5, blood must enter tube 41 with a predetermined minimum amount of pumping back when no infiltration has occurred. The ingress detector 32 may be CCD-based, camera-based, optical-based, and the like.

[000391] The pressure sensor 33 is in functional communication with the processor 37. The pressure sensor 33 can measure, estimate and/or determine the amount of pressure entering, leaving and/or flowing through the infusion site monitor 26 via ports 29 and 30. In some embodiments, when the processor 37 determines that the pressure in the pipe exceeds a predetermined threshold and/or is below a predetermined threshold, the processor 37 communicates an alarm or alert to the monitoring client 6 ( see Figure 1) which may signal valve 25 to stop the flow of fluid to patient 5. Pressure sensor 33 may be a resistive element that changes in resistance as a force is applied to the resistive element, the resistive element is stretched and/or the resistive element is pulled. The resistive element may be wrapped around the tube 41 so that as fluid pressure causes the tube 41 to expand, the resistance of the resistive element is measured and is associated with a pressure within the tube, e.g. can be measured and a lookup table can be used to look up an estimated pressure within the tube 41. In some embodiments, when the processor 37 determines that the pressure within the tube is greater than a predetermined maximum value or less than a predetermined value predetermined minimum, the processor 37 communicates an alarm or alert to the monitoring client 6 (see Figure 1) which may signal the valve 25 to stop the flow of fluid to the patient 5. Additionally or alternatively, the processor 37 may communicate a alarm or an alert to the valve 25 or to one or more of the pumps 19, 20 and 21 to stop the flow of fluid when the processor 37 receives from the pressure sensor 33 a measured pressure within the fluid tube 41 greater than a predetermined maximum value or less than a predetermined minimum value.

[000392] The fluid temperature sensor 34 is in functional communication with the processor 37. The fluid temperature sensor 34 can measure, estimate and/or determine the temperature of the fluid within the tube 41. In some embodiments, when the processor 37 determines that fluid temperature within tube 41 exceeds a predetermined threshold and/or is below a predetermined threshold, processor 37 communicates an alarm or alert to monitoring client 6 (see Figure 1) which may signal valve 25 to stop the flow of fluid to the patient 5. In some embodiments, a user may cancel the alarm or alert, for example, with the use of a monitoring client touch screen 6. Additionally or alternatively, the processor 37 may communicate an alarm or alert to valve 25 or to one or more of pumps 19, 20, and 21 to stop fluid flow when processor 37 receives an estimated temperature of the fluid within tube 41 indicating that the fluid is above a predetermined threshold and/or is below a predetermined threshold. The fluid temperature sensor 34 may utilize a temperature sensitive material, a positive temperature coefficient material, a negative temperature coefficient material, or other temperature sensing technology.

[000393] Patient temperature sensor 35 is in functional communication with processor 37. Patient temperature sensor 35 can measure, estimate and/or determine the temperature of patient 5 (see Figure 1). The patient's temperature 5 can be used to determine the patient's condition, compliance with a temperature affecting medication, or effect of a temperature affecting medication. The temperature of patient 5 (a patient condition parameter) may be communicated to monitoring client 6 (see Figure 1). In some embodiments, when the processor 37 determines that the patient 3's temperature exceeds a predetermined threshold or is below a predetermined threshold, the processor 37 communicates an alarm or alert to the monitoring client 6 (see Figure 1) which may signal the valve 25 to stop the flow of fluid to the patient 5, send an alert to a remote communicator, and/or notify a healthcare professional of the condition via an internal speaker 42 or vibration motor 43 within the site monitor infusion pump 26. Additionally or alternatively, the processor 37 may communicate an alarm or alert to the valve 25 or to one or more of the pumps 19, 20 and 21 to stop the flow of fluid when the processor 37 receives an estimated temperature from the patient temperature sensor 35 that exceeds a predetermined threshold or is below a predetermined threshold. The patient temperature sensor 35 may utilize a temperature sensitive material, a positive temperature coefficient material, a negative temperature coefficient material, or other temperature sensor technology.

[000394] The ambient air temperature sensor 36 is in functional communication with the processor 37. The ambient air temperature sensor 36 can measure, estimate and/or determine the temperature of the ambient air within the infusion site monitor 26 or , in other embodiments, the air temperature outside the infusion site monitor 26. An excessive ambient air temperature may be an indication of an electronic component failure, in some specific embodiments. In some embodiments, when the processor 37 determines that the temperature of the ambient air temperature sensor 36 exceeds a predetermined threshold or is below a predetermined threshold, the processor 37 communicates an alarm or alert to the monitoring client 6 (see Figure 1) which may signal valve 25 to stop the flow of fluid to patient 5. Additionally or alternatively, processor 37 may communicate an alarm or alert to valve 25 or to one or more of pumps 19, 20 and 21 to stop fluid flow when the processor 37 receives an estimated temperature from the ambient temperature sensor 36 that exceeds a predetermined threshold or is below a predetermined threshold. The ambient air temperature sensor 36 may utilize a temperature sensitive material, a positive temperature coefficient material, a negative temperature coefficient material, or other temperature sensor technology.

[000395] Referring to the drawings, Figure 3 shows a block diagram of a pump for infusing the liquid of the system of Figure 1 in accordance with an embodiment of the present description. Although pump 19 of Figure 3 is described as pump 19 of Figure 1, pump 19 of Figure 3 may be one or more of pumps 19, 20 and 21 of Figure 1 or may be included within any sufficient pump described. in this document.

[000396] Pump 19 includes a processor 37 coupled to a memory 38. The processor 37 is in functional communication with the memory 38 to receive processor-executable instructions configured for execution on the processor 37. In some embodiments, the processor 37 is , optionally, in functional communication with the user input 39, the air detector 410, the fluid temperature sensor 34, valves 47, 49, 51 and 52, a flow meter 48, an actuator 54, an air filter 50, a drain chamber 53 and/or a pressure sensor 33.

[000397] The pump includes an actuator 54 that operates on fluid contained within tubing 56 flowing through the pump. Actuator 54 may operate directly on tube 56 or may act against one or more combined membranes within actuator 54. In some embodiments, valves 47 and 49 cooperate with actuator 54 to pump fluid, e.g., liquid from the inlet port. 44 to the outlet port 45 through the tube 56. In some embodiments of the present description, the pump 19 does not contain any internal piping and interfaces with the external piping.

[000398] Air filter 50 filters air from tube 56. In alternative embodiments, air filter 50 is upstream of air detector 410. Valve 52 may activate to allow air to enter from tube 56 into a drain chamber 53 via a diversion tube 57.

[000399] Referring to the drawings, Figures 4 and 5 show a drip chamber retainer 58 that receives a drip chamber 59. As described below, the drip chamber retainer 58 includes a free flow detector accordingly. with an embodiment of the present description. Additionally, alternatively or optionally, the drip chamber retainer 58 may include a flow rate meter in accordance with some embodiments of the present disclosure. Figure 4 shows the drip chamber retainer 58 with a closed door 62 and Figure 5 shows the drip chamber retainer 58 with an open door 62. The drip chamber retainer 58 may include the drip chamber 7, the flow meter 10 and the free flow detector 13 of Figure 1 integrated together or some combination thereof. The drip chamber retainer 58 includes a start button 60 and a stop button 61. The drip chamber retainer may include a valve to prevent fluid from flowing therethrough or may signal another valve, e.g. 16 of Figure 1, to prevent the fluid from flowing.

[000400] The drip chamber retainer 58 optionally includes cameras 63 and 64 that can estimate fluid flow and/or detect free flow conditions. Although the drip chamber retainer 58 includes two cameras (e.g., 63 and 64), only one of the cameras 64 and 64 may be used in some embodiments. Cameras 63 and 64 can image a droplet as it is formed within the drip chamber 59 and estimate its size. Droplet size can be used to estimate fluid flow through drip chamber 59. For example, in some embodiments of the present disclosure, cameras 63 and 64 use an edge detection algorithm to estimate the size contour of a droplet. droplet formed within the dripping chamber 59; a processor therein (see processor 90 of Figures 12 of 14, for example) may assume that the contour is uniform from each angle of the droplet and may estimate the size of the droplet from the contour. In the exemplary embodiment shown in Figures 4 and 5, the two cameras 63 and 64 can jointly average the two contours to estimate the droplet size. Cameras 63 and 64 may use a reference background pattern to facilitate droplet size recognition as described herein.

[000401] In another embodiment of the present description, cameras 63 and 64 image the fluid to determine whether a free flow condition exists. Cameras 63 and 64 can use a background pattern to determine whether the fluid is flowing freely (i.e., droplets are not forming and the flow is flowing through the dripping chamber 59). Although the drip chamber retainer 58 includes two cameras (e.g., 63 and 64), only one of the cameras 64 and 64 can be used in some embodiments to determine whether a free flow condition exists.

[000402] Additionally or alternatively, in some embodiments of the present description, another camera 65 monitors the fluid tube 66 to detect the presence of one or more bubbles within the fluid tube. In alternative embodiments, other bubble detectors may be used in place of the camera 65. In still additional embodiments, no bubble detection is used in the drip chamber retainer 58.

[000403] Figure 6 shows a block diagram of another drip chamber retainer 67 in accordance with another embodiment of the present description. The drip chamber retainer 67 includes an optical drip counter 68 that receives fluid from an IV bag 69. In alternative embodiments, the optical drip counter 68 is a camera, is a pair of cameras, is a capacitive drip counter and similar. The drip chamber retainer 67 is coupled to a tube 70 coupled to a retainer clamp 71 that is controlled by a motor 72. The motor 72 may be coupled to a lead screw mechanism 73 to control a roller clamp 74.

[000404] The motor 72 may be a servo motor and may be used to adjust the flow rate through the tube 70. That is, the drip chamber retainer 67 may also function as a regulator and flow meter. For example, a processor 75 within drip chamber retainer 67 may adjust motor 72 such that a desired flow rate is achieved as measured by optical drip counter 68. Processor 75 may implement a control algorithm using from the optical drip counter 68 as feedback, e.g., a proportional, integral, and derivative ("PID") control loop with the output being to the motor 72 and the feedback being received from the optical drip counter 68.

[000405] In alternative embodiments, the motor 72, the lead screw mechanism 73, and the roller gripper 74 may be replaced and/or supplemented by an actuator that squeezes the tube 70 (e.g., with the use of a cam or linkage driven by a motor) or may be replaced by any sufficient roller, screw or slider driven by a motor.

[000406] The drip chamber retainer 67 may also include a display, for example, the display 76 as shown on the drip chamber retainer 58 of Figures 4 and 5. The display may be used to set the target flow rate , display the current flow rate and/or may provide a button, for example a touch screen button, to stop the flow rate (or a button 61 as shown in Figures 4 and 5 may be used to stop the fluid flow).

[000407] Referring again to Figure 4, in some specific embodiments of the present description, cameras 63 and/or 64 may be a camera cube manufactured with OmniVision of 4275 Burton Drive, Santa Clara, California 95054; for example, the camera cube could be one made for phone camera apps. In some embodiments of the present disclosure, cameras 63 and/or 64 may use a fixed focus and have a depth of field ("DOF") from 15 centimeters to infinity.

[000408] Cameras 63 and 64 may each have the blurred circle of an imaged point in the range of one of cameras 63 and/or 64 contained entirely within the area of a single pixel. In an exemplary embodiment, the focal length of the camera lenses of cameras 63 and 64 may be 1.15 millimeters, the F# may be 3.0, and the aperture of the lenses of cameras 63 and 64 may be 0.3833 millimeters. A first order approximation for the optical system of one or more of the cameras 63 and 64 can be made using matrix equations, in which each ray, r, is represented as the vector described in Equation (1) as follows :

[000409] In Equation (1) above, h is the height of the ray at the entrance to the camera system of cameras 63 and/or 64 and θ is the angle of the ray. Referring to Figure 7, when imaging a hypothetical point at distance dim from the lens of one of cameras 63 or 64 (which has focal length f) and the lens is at distance dfp from the focal plane, the corresponding matrix, Mcame that describes the camera (e.g., one or both cameras 63 and/or 64) is described by Equation (2) as follows:

[000410] To find the location in the focal plane, fp, that the ray reaches, a matrix multiplication as described in Equation (3) as follows can be used:

[000411] As illustrated in Figure 7, the diameter of the blurred circle, Dblurred, is shown as approximately the distance between the two points illustrated in Figure 7. This distance is found by tracing the rays of the dim point away from the lens on the geometric axis optics to the edges of the lens and then to the focal plane. These radii are given by the vectors shown in (4) as follows:

[000412] As shown in Figure 8, the blurred circle, Dblurred, is calculated and shown for a variety of lens-to-focal plane separations and lens-to-image separations. A contour map 77 is also shown in Figure 8. The x axis shows the distance in microns between the focal plane and a point located one focal length away from the lens of one of the cameras 63 and/or 64. The y axis shows the distance in meters between the lens and the point being imaged. The values that create the contour map 77 are the patch size divided by the pixel size; therefore anything between 1 and less is sufficient for imaging. As shown in Figure 8, the focal plane is located an additional focal length and 5 micrometers away from the lens.

[000413] Cameras 63 and/or 64 may use a second lens. For example, one or more of cameras 63 and/or 64 may utilize a second lens to create a relatively greater depth of field and a relatively greater field of view. Depth of field using two lenses can be calculated using the same analysis as above, but with the optical matrix modified to accommodate the second lens and additional distances, which is shown in Equation (5) as follows:

[000414] Figures 9 and 10 illustrate field changes with separation between the lens and camera and the corresponding change in camera focus. Figures 9 and 10 show the blurred circle divided by pixel size. Figure 9 shows the blurred circle divided by the pixel size when a 20 millimeter focal length lens is used. Figure 10 shows the blurred circle divided by the pixel size when a 40 millimeter focal length lens is used. The corresponding fields of view about the optical axis for the corners of the two configurations of Figures 9 and 10 are shown in the table in Figure 11.

[000415] As shown in Figure 11, in some embodiments, cameras 63 and 64 of Figures 4 and 5 may utilize a lens of focal length from 40 mm to 60 mm; This configuration may include placing one or more of cameras 43 and 64 within 50.8 millimeters (2 inches) of focus. In other embodiments of the present disclosure, other configurations may be used including those not shown in Figure 11.

[000416] For example, the following analysis shows how depth of field can be established for one or more of cameras 63 and 65: with the use of a lens of focal length, f, a distance, z, from the plane focal and a distance, d, from a point in space; a system matrix is shown in Equation (6) as follows:

[000417] Equation (6) reduces to Equation (7) as follows:

[000418] Equation (7) reduces to Equation (8) as follows:

[000419] Considering the points on the geometric axis, all heights will be zero. The point in the focal plane where different rays will collide is given by (9) as follows:

[000420] As shown above in (9), θ is the angle of the ray. The point in perfect focus is given by the lens marker equation given in Equation (10) as follows:

[000421] Equation (10) can be rearranged to derive Equation (11) as follows:

[000422] Inserting d from Equation (11) into (9) to show the collision point results results in Equation (12) as follows:

[000423] All rays leaving this point collide in the focal plane on the optical geometric axis. As shown in Equation (13), the situation when cameras 63 and/or 65 are offset by a distance δ from the focus is described as follows:

[000424] Equation (13) shows that by properly positioning the lens of cameras 63 and 64 in relation to the focal plane, the depth of field can be changed. Additionally, the spot size depends on the magnitude of the angle θ. This angle linearly depends on the aperture of the vision system created by cameras 63 and/or 64.

[000425] Additionally or alternatively, in accordance with some embodiments of the present description, cameras 63 and 64 can be deployed by adjusting various parameters, including: the distance to focus as it affects the compactness, alignment and sensitivity of the environmental vision system; the system's field of view; and the separation of focal plane and lens as it affects tolerances in system alignment and the sensitivity of the system to the environment.

[000426] Figure 12 is a block diagram of an imaging system 78 of the drip chamber retainer cameras of Figures 4 and 5 in accordance with an embodiment of the present description. Although the camera 63 of Figures 4 and 5 is described with reference to Figure 12, the camera 64 may also utilize the configuration described in Figure 12.

[000427] Figure 12 shows an imaging system 78 that includes a camera 63, a uniform backlight 70 to project light at least partially through the drip chamber 59, and an infrared ("IR") filter 80 that receives light from the uniform backlight 79. System 78 also includes a processor 90 that may be operatively coupled to camera 63 and/or uniform backlight 79.

[000428] The uniform backlight 79 may be an arrangement of light-emitting diodes ("LEDs") that have the same or different colors, a light bulb, a window for receiving ambient light, an incandescent light, and the like. In alternative embodiments, the uniform backlight 79 may be replaced by one or more point source lights.

[000429] The processor 90 may modulate the uniform backlight 79 with the camera 63. For example, the processor 90 may activate the uniform backlight light 79 for a predetermined amount of time and signal the camera 63 to capture at least one image and, therefore, signal the uniform backlight 79 to turn off. The one or more images from camera 63 may be processed by the microprocessor to estimate flow rate and/or detect free-flow conditions. For example, in one embodiment of the present disclosure, the system 78 monitors the size of droplets that are formed within the dripping chamber 59 and counts the number of droplets that flow through the dripping chamber 59 within a predetermined amount of time; the processor 90 may average the flow of individual droplets over a period of time to estimate the flow rate. For example, if droplets X each have a volume Y flow through the dripping chamber in time Z, the flow rate can be calculated as (X*Y)/Z.

[000430] Additionally or alternatively, system 78 may determine when IV fluid is flowing through drip chamber 59 (i.e., during a free-flow condition). The uniform backlight 79 projects through the drip chamber 59 to provide an image from the drip chamber 59 to the camera 63. The camera 59 can capture one or more images from the drip chamber 59.

[000431] Other orientations of the system 78 may be used to consider the sensitivity and/or orientation of the uniform backlight 79, the camera 63, the light characteristics of the uniform backlight 79, and the ambient light. In some embodiments of the present disclosure, processor 90 deploys an algorithm that utilizes a uniformity of images collected by camera 63 facilitated by uniform backlighting 79. For example, consistent uniform images can be captured by camera 63 when uniform backlighting 79 is utilized.

[000432] Ambient lighting can cause inconsistencies in images received from camera 63, such as that caused by direct sunlight. Therefore, in some embodiments of the present disclosure, an IR filter 80 is optionally used to filter out some effects of ambient light. For example, the IR filter 80 may be a narrowband infrared light filter placed in front of the camera 63; and the uniform backlight 79 may emit light that has approximately the same wavelength as the center frequency of the passband of the filter 80. The IR filter 80 and the uniform backlight 79 may have a center frequency of about 850 nanometers. In alternative embodiments, other optical frequencies, bandwidths, center frequencies, or filter types may be used in system 78.

[000433] Figure 13 is a graphic illustration of an image 81 captured by the camera 63 of the system of Figure 12, in accordance with an embodiment of the present description. Image 81 shows condensation 82 and a current 83 caused by a free-flow condition. Edge detection may be used to determine the position of current 83 and/or condensation 82, in some embodiments. Additionally or alternatively, a background or pattern image may be used as described below.

[000434] Figure 14 is a block diagram of an imaging system 84 of the drip chamber retainer cameras of Figures 4 and 5 in accordance with an embodiment of the present description. Although the camera 63 of Figures 4 and 5 is described with reference to Figure 14, the camera 64 may also utilize the configuration described in Figure 14.

[000435] System 84 includes an array of lines 85 that are opaque behind the drip chamber 59. The array of lines 85 can be used in detecting a free-flow condition of the system 84. The free-flow detection algorithm can use the presence or absence of droplets to determine whether a continuous flow condition (e.g., a free flow condition) exists or not. Referring now to Figure 15, a graphic illustration of an image 86 is shown as captured by the camera 63 of Figure 14 when a free-flow condition exists in the drip chamber 59 in accordance with an embodiment of the present description.

[000436] Image 86 illustrates the condition in which the drip chamber 59 experiences a free-flow condition and shows that the fluid stream 87 acts as a positive cylindrical lens. That is, as shown in Figure 15, the line array 85 as captured in an image by camera 63 shows an inverse line pattern 88 of the line array 85 compared to a non-free flow condition.

[000437] In some embodiments of the present disclosure, an illumination of about 850 nanometers optical wavelength may be used to create image 86. Some materials may be opaque in the visible spectrum and transparent in the IR near about 850 nanometers and , therefore, can be used to create the 85 line array. The 85 line array can be created using various rapid prototyping plastics. For example, line array 85 may be created using a rapid prototyping structure printed with an infrared opaque ink or coated with a metal to make line array 85. Additionally or alternatively, in some embodiments of the present disclosure , another method to create the 85 line arrangement is to create a circuit board with the lines placed in copper. In another embodiment, the line arrangement 85 is created by placing a piece of ribbon cable on the uniform backlight 79; The wires in the ribbon cable are opaque to the infrared spectrum, but the insulation is transparent and the wire spacing can be used for imaging by camera 63 (see Figure 14). In still further embodiments, an electrical discharge machined piece of thin metal. Metal is opaque and the gaps in the material can be controlled very finely during manufacturing to allow light to pass through the gaps.

[000438] Processor 90 deploys an algorithm to determine when a free flow condition exists. The processor 90 may be in functional communication with a computer-readable medium 91 (e.g., a non-transitory computer-readable medium) to receive one or more instructions for deploying the algorithm to determine whether a free-flow condition exists. The one or more instructions of the computer-readable medium 91 are configured for execution by the processor 90.

[000439] Referring again to Figure 14, blood may be used by system 84. For example, system 84 may determine when a free-flowing blood condition exists by utilizing camera 63, IV filter 80, and uniform backlighting. 79 configured, for example, for use using optical light having a wavelength of 850 nanometers or 780 nanometers, for example, when using bovine blood. Blood may appear opaque compared to images taken using water as the fluid.

[000440] The following algorithm implemented by processor 90 and received from computer-readable medium 91 can be used to determine when a free-flow condition exists: (1) establishing a background image 89 (see Figure 16); and (2) subtract the background image 89 from the current image. Additional processing can be performed on the resulting image.

[000441] In some embodiments of the present disclosure, the background image 89 of Figure 16 may be dynamically generated by the processor 90. The dynamic background image may be used to account for changing conditions, e.g., condensation or spatter 82 on the surface of the drip chamber (see Figure 13). For example, in a specific embodiment, for each new image captured by the camera (e.g., 63 in Figure 14), the background image has each pixel multiplied by 0.96 and the current image (e.g., the most recently captured image ) has a respective pixel multiplied by 0.04, after which the two values are added together to create a new value for a new background image for that respective pixel; this process can be repeated for all pixels. In yet another example, in a specific embodiment, if a pixel of the new image is in a row, x, and in a column, y, the new background image in the row, x, and column, y, is the value of the image previous background in row, x, and column, y, multiplied by 0.96, which is added to the pixel value in row, x, and column, y of the new image multiplied by 0.04.

[000442] When system 84 does not have water flowing through drip chamber 59 (see Figure 14), the resulting subtraction should be almost completely black, i.e., low pixel magnitudes, thus facilitating the algorithm to determine that the chamber drip tray 59 does not have water flowing through it.

[000443] Figure 17 shows an image 92 of the camera 63 when there is a droplet inside the drip chamber 59 (see Figure 14). Figure 18 shows a background image 93 used by system 84. When system 83 has a droplet as shown in image 92 of Figure 17, system 84 of Figure 14 has some high contrast locations in which the line array image is distorted by the lensing effect of the droplet as illustrated by an image 94 of Figure 19. Image 94 of Figure 19 is generated by taking, for each respective pixel, the absolute value of the subtraction of image 92 of Figure 92 from image 93 of Figure 18 and converting each respective pixel to a white pixel if the value is above a predetermined threshold or otherwise converting the pixel to a black pixel when the value is below the predetermined threshold. Each white pixel within image 94 of Figure 19 is a result of there being a difference for that pixel location between images 92 and 93 that is greater than a predetermined threshold.

[000444] For example, consider three respective pixels of Figures 17, 18 and 19 that have a row, x, and column, y location. To determine the pixel of row x and column y for image 94 of Figure 19, the pixel in row x and column y of image 92 of Figure 17 is subtracted from the pixel in row x and column y of image 92 of Figure 18, then the value absolute of the subtraction result is taken; and if the absolute value of the result is above a predetermined threshold (e.g., above a grayscale value of 128, for example), the pixel at the location of row x and column y of image 94 of Figure 19 is white, otherwise, the pixel at the location of row x and column y of image 94 of Figure 19 is black.

[000445] When it is determined that some high contrast locations exist within the image 94 of Figure 19, the processor 90 of the system 84 (see Figure 14) determines that droplets are being formed within the drip chamber 59 and no flow conditions free exists. Images of the droplets can be used to determine their size to estimate a flow rate as described herein.

[000446] Figure 20 is a graphical representation of some image processing that can be performed using Figures 17 to 18 to determine whether a free flow condition exists in accordance with an embodiment of the present description. Referring to Figures 20 and 19, all white pixels for each line are summed and are illustrated in Figure 20 as results 183. The y axis represents the line number and the x axis represents the number of white pixels determined for each respective line.

[000447] Referring now only to Figure 20, as previously mentioned, the number of white pixels for each line is summed and is illustrated as results 183, which are used to determine if or when a free flow condition exists. In some specific embodiments, processor 90 of system 84 (see Figure 14) determines that a free-flow condition exists when a predetermined number of contiguous values from the summed rows of results 183 exist above a threshold 184. For example, within the results 183, a plurality of lines represented generally by 185 have a total value above threshold 184. When it is determined that more than a predetermined number of contiguous summed lines exist within results 183, a free-flow condition is determined to exist by processor 90 of Figure 14. For example, as shown in Figure 20, the plurality of contiguous lines 185 is below the predetermined number of contiguous summed lines, and therefore it is determined that a free-flow condition does not exist.

[000448] Figure 21 shows an image 95 showing a current as captured by the camera 63 of Figure 14 when a free flow condition exists. Figure 22 shows a background image 96. Figure 23 shows an image 97 formed by the absolute value of the difference between image 96 of Figure 22 and image 95 of Figure 21 when the absolute value is converted or into a white pixel (when the absolute value of the difference is above a threshold) or in a black pixel (when the absolute value of the difference is below the threshold). As shown in Figure 23, locations of high contrast caused by the reverse orientation of the lines in the top-to-bottom current run are detectable by processor 90. Processor 90 of Figure 14 can use image 97 to determine whether a flow condition free exists with the use of the algorithm described above.

[000449] That is, as shown in Figure 24, results 186 are shown having a contiguous range 187 of results 186 that are above a threshold 188. Because the contiguous range 187 of summed rows is greater than a predetermined threshold number of contiguous valves above threshold 188, a free flow condition is determined to exist by processor 90 (see Figure 14). That is, the contiguous range of results 186 above threshold 188 is greater than a predetermined threshold range of contiguous valves; therefore, processor 90 determines that a free-flow condition exists when using results 186 of Figure 24.

[000450] In yet a further embodiment of the present description, the intensity, squared intensity or other function may be used to produce results 183 and/or 186. In yet a further embodiment, one or more data smoothing functions may be used to smooth 183 and/or 186 results, such as a spline function, cubic spline function, B-spline function, Bézier spline function, polynomial interpolation, moving averages, or other data smoothing functions.

[000451] For example, a camera image 63 of Figure 14, e.g., image 95 of Figure 21, can be subtracted from a background image, e.g., image 96 of Figure 22 to obtain intensity values. For example, a pixel of row x and column y of Figure 21 can be subtracted from a pixel of row x and column y of image 96 of Figure 22 to create an intensity value in row x and column y; this can be repeated for all pixel locations to obtain all intensity values. The intensity values of each row may be summed to obtain results 183 and/or 186, so that the processor 90 may determine that a free-flow condition exists when the summed rows of intensity values have a contiguous range of summed rows. above a threshold. In some embodiments, the intensity values are converted to an absolute value of the intensity values and the summed lines of the absolute values of the intensity values are used to determine whether a contiguous range of the summed lines of the absolute value is above a threshold range of contiguous values. Additionally or alternatively, the intensity may be squared and then the processor 90 may sum the squared intensity lines and determine whether a contiguous range of the summed rows of squared intensity values exists beyond a threshold range of the contiguous values to determine whether a free flow condition exists. In some embodiments, a predetermined range of contiguous values above a threshold (e.g., minimum and maximum ranges) of summed rows of intensity values or squared intensity values may be used by processor 90 to determine whether a liquid droplet is within of image. For rows of intensity values (or squared intensity values) may be summed and a range of the summed values may be above a threshold number; If the range of contiguous values is between a minimum range and a maximum range, the processor 90 may determine that the range of contiguous values above a predetermined threshold is a droplet within the field of view of the camera 63. In some embodiments hereof description, the summed rows of intensity values or squared intensity values can be normalized, for example, normalized to have a value between 0 and 1.

[000452] The following describes a cubic spline smoothing function (i.e., cubic spline type function) that can be used on the summed rows of intensity values or on the summed rows of squared intensity values prior to determination by processor 90 to determine whether a free flow condition exists. In some specific embodiments, the cubic spline-like function may be used to identify blocks, as described below, which may facilitate the processor 90's identification of free-flow conditions.

[000453] The cubic spline type function is an analogy to the cubic spline, but it smoothes the data set rather than faithfully imitating a given function. By having the data sampled in the range [0,1] (e.g., adding along a line of squared intensity or intensity that is normalized), the processor 90 can find the best fit set of cubic functions in the ranges [ x0, x1], [x1, x2], ..., [xN-1, xN] with x0 = 0 and xN = 1 where the total function is continuous with continuous derivatives and continuous curvature.

[000454] The standard cubic spline definition is illustrated in Equation (14) as follows:

[000455] with the functions Ai, Bi, Ci, Di defined as in the set of Equations (15):

[000456] Equations (14) and (15) guarantee continuity and continuity of curvature. The only values that can be freely chosen are yi, It is . Please note that Equation (16) is chosen as follows:

[000457] that is, the function is flat at 0 and 1. The remainder must satisfy the following set of Equations (17):

[000458] The set of Equations (17) can be rewritten as the set of Equations (18) follows:

[000459] In turn, this becomes Matrix Equation (19):

[000460] The set of Equations (19) can be rewritten as the set of Equations (20):

[000461] The choice of values in the y vector using a least squares criterion on the collected data is shown in Equation (21) as follows

[000462] That is, Equation (21) is the minimum deviation between the data and the spline, that is, an error function. The y values are chosen to minimize the error as defined in Equation 21; The vector of predicted values can be written as illustrated in Equation (22) as follows:

[000463] The matrix elements in parentheses of Equation (22) depend on the revaluation corresponding to each data point, but this is a fixed matrix. Thus, the final equation can be determined using the pseudoinverse. In turn, the pseudoinverse depends only on the x-locations of the data set and the locations at which the brakes on the cubic spline are defined. The implication of this is that once the spline geometry and image size are selected, the best choice for y given a set of measured values ym is illustrated in Equation (23) as follows:

[000464] The cubic spline through the square sum intensity function of the image will then be given by Equation (24):

[000465] As it is desired to find the maximum values of the cubic spline, the derivative of the spline is also necessary. The cubic spline derivative is given by Equation (25) as follows:

[000466] Equation (25) can be written as Equation (26):

[000467] Once the current values of y are found, the cubic spline yes and its derivative y'es can be calculated. Cubic spline data may include "blocks" of data that include values above a predetermined threshold. A tube block is formed by the liquid flowing out of the tube into the drip chamber 59 and a cluster block is formed as the liquid collects at the gravity end of the drip chamber 59 (see Figure 14).

[000468] The following algorithm can be applied to cubic spline data: (1) determine the local maximum of the cubic spline data using the derivative information; (2) determine the block surrounding each local maximum including all points where the cubic spline value is above a threshold value; (3) merge all intersecting blocks; (4) calculate information about the data block including the center of mass (intensity), the second moment of mass (intensity), the lower x-value of the block, the upper x-value of the block, the average value of the original sum of the squared intensity data in the block, the standard deviation of the original sum of the squared intensity data in the block, and the average intensity of a high pass filtered image defined in the block; and (5) interpret the collected data to obtain information about when droplets occur and when the system is running.

[000469] The average intensity of a high-pass filtered image defined in the block is used to determine whether the block created by each contiguous band of spline data is a result of a high-frequency artifact (e.g., a droplet) or a low frequency artifact. This will act as a second background filter that tends to remove artifacts such as condensation from the image. That is, all previous images in a temporary image memory store (e.g., 30 previous frames, for example) are used to determine whether the data is a result of high-frequency motion between frames. If the block is a result of low-frequency changes, the block is removed, or if the block is a result of high-frequency changes, the block is retained for further analysis. A finite impulse response filter or an infinite impulse response filter can be used.

[000470] Each block is plotted along its physical extent with a height equal to the average value of the data within the block. If a block has an average high-pass filter image value lower than the threshold, it is an indication that it has existed for several images and can therefore be removed.

[000471] Free-flow conditions may be determined by the processor 90 to exist using the blocks when the tube block extends nearly as far as the cluster block, the tube block and the cluster block merge, and/or the The summed range of the widths of the tube and cluster blocks (or all blocks) is greater than a predetermined threshold, for example, the total length of the blocks exceeds 380 pixels wide. The processor 90 may detect a droplet as the transition of the tube block from a larger width to a smaller width occurs as a result of droplet formation in the tube and as the droplet leaves the pipe (i.e., tube) opening of the chamber. drip 59. The processor 90 can detect this by looking at the ratio of the current tube block width to the tube block width of the previous image, e.g., an image in which the ratio is less than 0.9 while it is simultaneously a local minimum can be considered by processor 90 to be an image formed immediately after the droplet has formed.

[000472] Various filtering algorithms can be used to detect condensation or other low frequency ratification, such as: If a block has a low average value in the high pass filter image, then it may be condensation. This artifact can be removed from consideration. Additionally or alternatively, long blocks (e.g., greater than a predetermined threshold) with a low average high-pass value are possibly currents, as current images tend to remain unchanged.

[000473] Processor 90 may, in some specific embodiments, use the block data to count droplets therethrough using system 84 as a droplet counter. The processor 90 may also use width changes in the cluster block as a droplet disturbs the water to determine whether a bubble formed with the droplet reaching the tank. For example, the processor 90 may determine that a block forms below the tank block, then the processor 90 may determine that a bubble forms when a droplet hits the water. The bubble may be filtered by processor 90 to determine whether a predetermined value of the total block ranges indicates that a free flow condition exists.

[000474] In some embodiments of the present disclosure, the depth of field of the system 84 may have a narrow depth of field to make the system 84 less sensitive to condensation and droplets on the chamber walls. In some embodiments, a close focus system may be used.

[000475] Referring now to Figure 25, in another embodiment of the present description a model 189 is used to determine whether a free flow condition exists. Template 189 is used by processor 90 of Figure 14 to determine a pattern matching score 190. Image 94 of Figure 19 may be compared to pattern 189 (e.g., a difference between a background image and an image captured by the camera 63 of Figure 14 which is then converted to either a black pixel if the difference is below a threshold value or a white pixel if the difference is above a threshold value). If the pattern match score 190 is above a predetermined threshold, a free flow condition is determined to exist. Template matching may utilize a template matching algorithm as found in the Open Source Computer Vision ("OpenCV") library. For example, template 189 can be used by calling the OpenCV library's matchTemplate() function using the CV_TM_CCOEFF method or the CV_TM_CCOEFF_NORMED method. The CV_TM_CCOEFF method uses the pattern matching algorithm illustrated in Equation (27) as follows: on what:

[000476] The I denotes the image, the T denotes the model and the R denotes the results. The summation is done over the model and/or the image patch, so that: x'= 0...w-1 and y'=0...h-1.

[000477] The results R can be used to determine how much the model T is matched at a particular location within the image I as determined by the algorithm. The OpenCV template matching method of CV_TM_CCOEFF_NORMED uses the pattern matching algorithm illustrated in Equation (28) as follows:

[000478] In another embodiment of the present disclosure, the template matching algorithm uses a Fast Fourier Transform ("FFT"). In some embodiments, any of the OpenCV matchTemplate() function methods may be used, for example, CV_TM_SQDIFF, CV_TM_SQDIFF_NORMED, CV_TM_CCORR and/or CV_TM_CCORR_NORMED.

[000479] CV_TM_SQDIFF uses the pattern matching algorithm illustrated in Equation (29) as follows:

[000480] CV_TM_SQDIFF_NORMED uses the pattern matching algorithm illustrated in Equation (30) as follows:

[000481] CV_TM_CCORR uses the pattern matching algorithm illustrated in Equation (31) as follows:

[000482] CV_TM_CCORR_NORMED uses the pattern matching algorithm illustrated in Equation (32) as follows:

[000483] In yet another embodiment of the present disclosure, a model of a grayscale image of a free-flow condition is compared to an image taken by camera 63 of Figure 14 to determine whether a free-flow condition exists. In some embodiments, the template matching function within the OpenCV library may be utilized.

[000484] Referring now to Figures 26 and 27; In yet a further embodiment of the present disclosure, the algorithm for determining when a free-flow condition exists that runs on processor 90 of Figure 14 may utilize an algorithm for determining whether a template pattern corresponds to an array of pixels that utilizes pattern detection. edge followed by line detection. As shown in Figure 26, an image 98 is formed from an image 99 of Figure 27, using edge detected followed by line detection. The resulting lines can be used by processor 90 to determine that a free flow condition exists. As shown in Figure 26, the feature that appears after this processing by processor 90 are lines that have a different slope than the expected 45° slope of the background reference image. Lines that have the angle of the background image can be filtered from Figure 26, in some embodiments. Lines can be detected as edges using a Canny algorithm as found in the OpenCV library with the Hough algorithm to determine the slope of lines also found in the OpenCV library.

[000485] Figures 28 to 32 illustrate various background patterns that can be used to detect a free-flow condition or estimate the size of a liquid droplet. When used with later patterns of Figures 28 to 32, the cameras 102 mentioned for use in Figures 28 to 32 may be the cameras 63 or 64 of Figures 4 or 5, the camera of Figure 6, the camera 63 of Figure 14 may be , each, coupled to a respective processor to process images from the camera, such as processor 75 of Figure 6 or processor 90 of Figure 14.

[000486] Figure 28 is a block diagram of an imaging system 100 for use with drip chamber 104 (e.g., a drip chamber as found in the drip chamber retainer of Figures 4 to 5 or Figure 6 ) having a back pattern 101 with stripes and a light source 102 that shines on the stripes from a location adjacent to a camera 103 in accordance with an embodiment of the present description. Any droplets or free-flowing streams within the drip chamber 104 distort the image taken by the camera 103. A processor coupled to the camera 103 (e.g., the processor 75 of Figure 6) may use the distortions of the subsequent pattern 101 as captured by the camera. 103 to estimate flow rate and/or detect free flow conditions.

[000487] Figure 29 is a block diagram of an imaging system 105 for use with drip chamber 104 that has a striped back pattern 101 and a light source 102 that shines on the stripes behind the back pattern 101 relative to an end opposite a camera 103 in accordance with an embodiment of the present description. Figure 30 shows an image from camera 103 of Figure 29 as a droplet distorts the back pattern 101 of Figure 26 in accordance with an embodiment of the present description. Note that, as shown in Figure 30, the streaks of the back pattern 101 are distorted by a droplet (or will be distorted by a free-flowing current) from the drip chamber 104 as imaged by the camera 103. This distortion can be used to to estimate droplet size, to calculate the flow rate through a fluid chamber retainer, or to determine whether a free flow condition exists.

[000488] Figure 31 is a block diagram of an imaging system for use with the drip chamber retainer of Figures 4 to 5 or Figure 6 that has a back pattern with a checkerboard pattern and a source of light shining on the stripes behind the posterior pattern relative to an end opposite a camera in accordance with an embodiment of the present description. Figure 32 shows an image from the camera of Figure 31 when a droplet distorts the back pattern 107 of Figure 26 in accordance with an embodiment of the present description. In yet another embodiment, the background may be formed using a plurality of random dots and/or circles.

[000489] Referring to Figures 28 to 32, the Lensing Effect of a droplet (i.e., the distortion of the posterior pattern from the view of a camera) can be used to measure the radius of the droplet. The radius of the droplet is related to the effect it has on the light that passes through it. By measuring the change to the calibration grid as seen through the droplet, the radius and therefore the volume of the droplet can be calculated. For example, the magnification of a test grating of known size as seen through the droplet could be measured optically and the radius inferred from that measurement. The relationship between the ray and the droplet can be calculated and/or can be determined using a lookup table that has been generated empirically.

[000490] Figure 33 shows a block diagram of an air detector 108 using a camera 109 in accordance with an embodiment of the present description. The air detector 108 may be the air detector 24 of Figure 1, the air detector 410 of Figure 2 or Figure 3, or the air detector 65 of Figure 5. Additionally or alternatively, in some specific embodiments, the air detector 108 may be formed within the drip chamber retainer 58 and the camera 109 may be the camera 65 of the drip chamber retainer 58 (see Figures 4 and 5).

[000491] The air detector 108 includes the camera 109, a backlight 110, a processor 584, and a memory 585. The backlight 110 projects light through the tube 111. The camera may optionally include an IR filter on its lens and/or the backlight can be turned to an infrared wavelength or bandwidth, for example, to match the IR filter.

[000492] Camera 109 may be operatively coupled to one or more processors 584 that are in functional communication with a computer-readable memory 585, e.g., RAM, ROM, disk, hard drive, memory, etc. The computer-readable memory 585 may include one or more operative instructions for execution by the one or more processors. The one or more operating instructions may implement an algorithm to detect or determine the presence of air within the tube 111; for example, determining or detecting the presence of one or more bubbles within the tube 111.

[000493] Additionally or alternatively, the system 108 can be used to detect the status of the tube 111 designed to transport fluid, for example, in this example, the IV tubing. Camera 109 may be a digital camera that captures images from tube 111 that is backlit with a diffuse light from a backlight 110. The backlight 110 may consist of a clear plastic material side-illuminated with an array of LEDs (e.g., as used). on a liquid crystal display). The camera 109 may capture one or more images so that the one or more processors may detect or determine the following: (1) whether the tube 111 has been installed in the device; (2) whether tube 111 has been charged (i.e., is filled with liquid); (3) whether there are bubbles in the tube; and/or (4) the color and opacity of the fluid in the tube.

[000494] Referring now to Figures 34, 35 and 36 for a description of an exemplary use of the system 108 of Figure 33. The detection algorithm residing within memory 585 and executed by processor 584 (see Figure 33) uses three model images: one representing no tubes installed; another representing a tube installed with clear liquid in it; and another representing a thin vertical slice of a bubble as shown in Figure 34. The algorithm quantifies how closely each section of the tube 111 corresponds to the bubble model of Figure 34, the no-tube model or the tube model with liquid in it. The matching algorithm may utilize the OpenCV pattern matching function, matchTemplate(), described in Equation (14) or Equation (15) above, or an FFT pattern matching algorithm. In a still further embodiment, any of the openCV matchTemplate() pattern matching methods can be used, such as, for example, CV_TM_SQDIFF, CV_TM_SQDIFF_NORMED, CV_TM_CCORR and/or CV_TM_CCORR_NORMED.

[000495] The pattern matching algorithm can scan from one side to the other side, for example, from left to right. As the 584 processor scans through the image, the pattern matching algorithm attempts to match each template to a scanned section. If a model matches and several scans later no model matches and finally another model matches, the processor can interpolate that the last model is the most likely model that should have been matched. For example, when scanning from left to right, in region 191, the model of a tube with liquid in it matches. When transitioning one side of the bubble 112 from the left, a region 194 on the left side of the bubble within the box 112 may not correspond to any model, and finally, within the box 112, the bubble may correspond to the air model in the region 193; the 584 processor may assume that the reason the pattern matching algorithm could not match the intermediate region of 194 with a template is because the bubble image began to alter the camera's view. Therefore, in this example, the region 194 in which no template was determined to match, the processor 584 could assume which bubble was present. Note also that interpolation can be used in region 195.

[000496] If there is a close match (including interpolation as described above), a bubble can be identified as shown in box 112. The size of the bubble in box 112 can be estimated based on the diameter of tube 111 (or known in advance or measured by camera 109 of Figure 33) and the bubble length found in the template matching algorithm, for example, as determined by box 112. Box 112 may model the bubble as a cylinder that has the diameter of tube 111. Bubble information can be compared frame by frame to track how many bubbles have moved across the field of view and their sizes (and thus the total amount of air delivered to a patient can be tracked). The processor 584 may issue an alert or alarm if any bubble exceeds a given size, if the total amount of air passing through the tube 111 exceeds a predetermined threshold, or if the total amount of air passing through the tube 111 exceeds a predetermined threshold. within a predetermined amount of time. In some embodiments, the color of the fluid can be used to estimate and/or determine the amount of air dissolved within the liquid within the tube 111.

[000497] In some embodiments, the bubble in Figure 36 can have its shape estimated. For example, edge detection can be used to identify the left and right edges of the bubble to estimate its volume, for example, Canny edge detection, a first-order edge detection algorithm, an edge detection algorithm second-order, an edge detection algorithm based on phase congruence and the like. The edge detection algorithm can utilize one found in OpenCV. Additionally or alternatively, the edge detection algorithm may calculate the average of the previous 5 pixels on one side (e.g. the left side) and compare this to an average of the next 5 pixels (e.g. the right side) and when the change exceeds a predetermined threshold, it can be determined that the bubble edge is present.

[000498] Additionally or alternatively, the camera 109 may capture an image with a threshold amount of red liquid within the tube 111 so that the one or more processors 584 determine that blood is present within the tube 111. For example, the system 108 having the camera 109 of Figure 33 can be used to form the infiltration detector 32 of Figure 2. One or more of the pumps, for example, pumps 19, 20 and 21 can be used to create a back pressure to determine whether the catheter is properly in the vein. That is, if the catheter is properly inside the vein, then a small amount of negative pressure inside the tube should draw blood into the tube. As shown in Figure 37, blood 113 can be captured within an image taken by the camera 109 of Figure 33, which is then processed to determine that a red threshold exists. Figure 38 shows a region 114 determined by the one or more processors, for example, processor 37 of Figure 2, that a red color threshold exists. White pixels depict that a threshold amount of red was detected and a black pixel depicts that a threshold amount of red was not detected for that pixel.

[000499] In another embodiment, the pixels are converted to grayscale and then a threshold amount of a dark color can be used to determine that blood exists in each individual pixel. For example, if it is determined that the pixel is below a threshold (e.g., closer to black than a threshold), it may be determined that that pixel is blood and is thus converted to white while the remaining pixels are converted to black (or other modalities, vice versa). For example, the image taken may be in RGB format which is then converted to a grayscale image using the OpenCV library's free space cvtColor() function using the color space conversion code CV_RGB2GRAY . The threshold quantity can be 50, 128 or can be dynamically adjusted.

[000500] The processor 37 can determine that infiltration has occurred when the infusion site monitor 26 of Figure 2 receives no blood or less than a predetermined amount of blood into the tube when a predetermined amount of negative pressure is present within the tube, for example, when running an infusion pump in reverse. The amount of blood may be determined by summing the white pixels within region 114. The tube may include fiducials to help locate the tube and/or the tube retainer. Additionally or alternatively, fiducials can be used to indicate distance, for example, the volume of blood in the tube can be correlated to the length of blood within the tube with the use of fiducials, for example, to prevent drawing too much blood during a test. infiltration.

[000501] Figure 39 shows an infiltration detector 115 in accordance with an embodiment of the present description. The infiltration detector 115 of Figure 39 may be the infiltration detector 32 of Figure 2. The infiltration detector 115 includes a photodiode coupled to a T-connector 117. The T-connector connects the tube 118 to the tube 119 that feeds the liquid The infiltration detector 115 also includes an LED 122 that projects light onto the skin 124. The photodiode 116 and the LED 122 may be coupled to a processor that implements an algorithm to determine when infiltration has occurred, e.g., the processor 37 of the infusion site monitor 26 of Figure 2. The algorithm may be implemented by an operative set of processor-executable instructions (e.g., as stored in a memory 38) configured to execution by the processor (e.g., processor 37).

[000502] Blood entering tube 119 and found around the catheter has significant light absorption properties at specific wavelengths that would minimize the passage of light from LED 122 through a light path passing through soft tissue, vein wall, venous blood, and fluid in the IV catheter and tubing 119. When infiltration has occurred, fluid should surround the inner portion of the catheter 121 (e.g., 18 gauge) and the amount of light from the LED 122 to the photodiode 116 is reduced from the optical absorption caused by the blood is reduced from the optical absorption caused by the blood. This is in contrast to an infiltrated state in which the IV fluid surrounding the catheter 121 minimally absorbs or attenuates the same wavelength of light absorbed by the venous blood and therefore allows a greater intensity of light to pass from the LED 122, through from the soft tissue, extravasated fluid, and then to the catheter 121 and IV tubing 119 to the light detector, e.g., the photodiode 116.

[000503] The photodiode 116 may be arranged so that it can receive any light passing through a catheter 121 and tube 119. The T-connector 117 is configured to allow fluid to simultaneously pass into the catheter 121 from of tube 118 through tube 119 and allow light from tube 119 to be diverted to photodiode 116.

[000504] LED 122 emits light at a wavelength that is attenuated by the hemoglobin in the blood and is positioned to illuminate the skin surface 124 near the open end of the catheter 121. When the catheter 121 is appropriately placed within the vein 126, attenuation of the illumination of the LED 122 by the blood reduces the amount of light reaching the photodiode 116. Additionally, when the catheter 121 is no longer positioned within the vein 126 (e.g., which occurs when an infiltration occurs), the illumination of the LED 122 passes to catheter 121 and through tube 119 to be detected by photodiode 116.

[000505] Figure 40 shows a graph 127 illustrating the optical absorption of oxygenated and deoxygenated hemoglobin in accordance with an embodiment of the present description. Graph 127 shows that both oxygenated and deoxygenated hemoglobin have strong absorption in the range of 530 to 590 nanometers and in the range of 400 to 450 nanometers. Referring again to Figure 39, in some embodiments of the present disclosure, the LED 122 and the photodiode 116 may be configured to emit and absorb, respectively, optical wavelengths of 405 nanometers, 470 nanometers, 530 nanometers, 590 nanometers, and 625 nanometers. In some embodiments, the photodiode 116 may be a silicon photodetector with a measurable response of 400 nanometers to 1,000 nanometers.

[000506] Referring now to Figure 41, another infiltration detector 128 in accordance with another embodiment of the present description is shown. The infiltration detector 128 includes a laser 129 to further illuminate the vein 126. The photodiode 116 is placed at the end of a syringe 130, which includes a copper tape wrapper to minimize stray light. The LED 122, the laser 129 (e.g., a laser pointer), or both can be used to illuminate the end of the catheter 121. The LED 122 can emit light having wavelengths of about 625 nanometers and the laser 129 can emit red wavelengths of light.

[000507] In some embodiments of the present disclosure, the catheter 121 and/or the tube 119 includes a stainless steel needle (e.g., 18 gauge) that has connectors wrapped in aluminum foil. In still further embodiments of the present disclosure, the LED 122 and/or the laser 129 may be modulated to enhance detection by the photodiode 116.

[000508] The syringe 130 can be used to apply a negative pressure to the tube 119. The processor 37 of Figure 2 can be coupled to the photodiode 116 and a syringe position sensor 130 to determine whether an infiltration has occurred. If after the syringe 130 (either manually or via an automatic actuator) is pulled back a sufficient amount of distance and no blood is detected by the photodiode 116 (e.g., from spectral absorption by the blood), the processor 37 may issue an alert and/or alarm to indicate that an infiltration has occurred.

[000509] In another embodiment, a small optical fiber disposed through the catheter 121 or needle illuminates the tip area of the catheter 121, for example, the LED 122 is coupled to the fiber optic cable to guide the light to the vein 126. Additional or alternatively, a pulse oximeter over the IV site can be used to automatically measure a baseline absorption profile to detect changes caused by an infiltration, for example, using the processor 37.

[000510] In still additional embodiments, a fluorescent coating is optionally applied to the needle tip of the catheter 121 that is excitable by light at a wavelength significantly absorbed by venous blood. For example, the colored light that is absorbed by hemoglobin would not be detectable when the catheter 121 is properly located in the vein. When the catheter 121 is located outside the vein, this light would not be absorbed and would become detectable by the photodiode 116. The fluorescent coating will emit less when the excitation light is absorbed by the hemoglobin and the emitted light may also be absorbed by the hemoglobin.

[000511] For example, the light emitted from the fluorescent coating may be different from the excitation light, for example, from the LED 122 and the photodiode 116 may include a filter to filter the excitation light from the LED 122 and receive the light that is emitted. from the excited fluorescent coating. In some embodiments, the fluorescent coating may fluoresce when black light is applied. Additionally or alternatively, LED 122 may be modulated.

[000512] Figure 42 shows a perspective view of an occluder 131 in accordance with an embodiment of the present description. Figure 43 shows a side view of the occluder 131 and Figure 44 shows a side view of the occluder 131 in operation. Referring now to all of Figures 42, 43 and 44, the occluder 131 includes occluder edges 132 and a pivot 133. The occluder 131 may include a spring (not shown) for forcing the occluder edges 132 against a tube 135. Additionally or alternatively, the occluder 131 may include an actuator 134 for actuating the occluder 131 against the tube 134.

[000513] The occluder 131 can be used within a peristaltic pump so that when a port is opened to position the tube 135, the occluder 131 is opened to place the tube 135 within the region of the occluder edges 132. When the port is open again, the occluder 131 can transmit from an open to a relaxed state by the action of the actuator 134 of occluding the tube 135.

[000514] Figure 45 shows a side view of a valve 136 for use in a cassette in accordance with an embodiment of the present description; Figure 46 shows a top view of valve 136; and Figure 47 shows another side view of valve 136 installed within a cassette in accordance with an embodiment of the present description. As is easily seen in Figure 45, a trajectory 137 illustrates fluid flow. In Figure 46, the exit hole 138 and the reentry hole 139 are visible. Figure 47 shows a membrane 140 when the valve 136 is installed in a cassette. The membrane 140 may be established to re-compress the valve 136 and may be 0.813 millimeters (0.032 inches) thick. The membrane 140 may use a UV-cured adhesive. The membrane 140 prevents the fluid from flowing in the wrong direction, for example, opposite to that of the trajectory 137 as shown in Figure 45. When the fluid tries to flow in the wrong direction, the suction force presses the membrane 140 against the exit hole 138 preventing fluid from flowing from the reentry hole 139 to the outlet hole 138. Additionally or alternatively, a plunger coupled to an actuator may be used to compress the membrane 140 to further close the valve 136. In a still further embodiment of the present description , a positive or negative pressure may be applied to the top of the membrane 140 to control the valve 136.

[000515] Figure 48 shows a slide valve 141 that has an inclined plane to provide sealing in accordance with an embodiment of the present description. The slide valve 141 includes a sealing surface 142 and a mounting surface 143. As seen from Figure 49 which shows a side view of the slide valve 141, the slide valve 141 includes spring hoops 144 and a wedge 145 to create a downward force to seal the port 146 of the assembly 147 as shown in Figure 50.

[000516] A downward force on the spring hoops 144 causes the slide valve 141 to slide away from the mounting surfaces 143 exposing the valve port 146. When released, the spring hoops 144 force the sealing arm 148 toward the mounting surfaces 143 and the downward forcing wedges 145 make contact with a counterpart molded into the mounting 147 and force the sealing surface 142 into the valve port sealing surface 146.

[000517] Figures 51 to 55 show a vent 149 for a reservoir 150 in accordance with an embodiment of the present description. Breather 149 may be used on fluid reservoirs 2, 3, or 4 in Figure 1, may be used on air filter 50, or with drain chamber 53 of pump 19 as shown in Figure 3. The breather includes a septum 151, an air permeable filter 151 and a tube 153. In some embodiments of the present disclosure, a reservoir 150 of an infusion substance is rigid, e.g., a rigid IV bag or other fluid reservoir for a fluid pumping device. Reservoir 150 may include a vent 149 to permit flow of fluid out of a rigid reservoir 150 by venting fluid reservoir 150 with an air permeable filter 152. In some embodiments, vent 152 may not be impermeable to water vapor. 'water. However, by placing an oil plug 154 in-line between the fluid reservoir 150 and the air filter 152, losses of brewing substance 155 are reduced because the oil 154 prevents the brewing substance from evaporating through the oil plug. 154.

[000518] The oil plug 154 is created by placing the septum 151 upstream of the reservoir 150 in a relatively narrow cross-section of the reservoir 150 as shown in Figures 51, 52, 53, 54 and 55. As shown in Figure 52, the oil 154 is injected through the septum 151 via a filling needle 156 before injecting the infusion substance 155 (as shown sequentially in Figures 53 and 54). A quantity of oil 154 is left between the air filter 152 and the infusion substance 155 at the end of filling. As air is drawn into the reservoir 150 through the air filter 152, as shown in Figure 55, the oil 154 advances with the infusion substance 155 preventing evaporative losses.

[000519] Additionally or alternatively, in some embodiments, the oil plug 154 is preloaded into the tube 153 between the septum 156 and the air filter 152; for example, as would be the case if the filling procedure began as shown in Figure 52.

[000520] Figures 56 to 58 illustrate the stages of a flow meter 157 in accordance with an embodiment of the present description. Figure 56 illustrates a first stage, Figure 57 illustrates a second stage, and Figure 58 illustrates a third stage. The stages of Figures 56 to 58 can be implemented as a method in accordance with an embodiment of the present description. A pump disclosed herein may be coupled upstream through the inlet port 162 and/or an infusion pump may be coupled to the downstream outlet port 163 to create fluid from the inlet port 162 through the flow meter 157 to output port 163.

[000521] The flow meter 157 includes a chamber 158 divided by a membrane 159. The membrane 159 divides the chamber 158 into a first section 160 and a second section 161. The flow meter 157 includes an inlet port 162 and a outlet 163. Flow meter 157 includes first 164, second 167, third 166, and fourth 165 valves. The inlet port 162 is in fluid communication with the first section 160 through the first valve 164 and the second section 161 through the fourth valve 165. The outlet port 163 is in fluid communication with the first section 160 through of the third valve 166 and the second section 161 through the second valve 167. The chamber 158 may be spherically shaped or cylindrically shaped. The chamber 158 may be rigid, for example, the chamber 158 may be made of a plastic, metal, or other rigid or semi-rigid material.

[000522] The flow from the inlet port 162 to the outlet port 163 can be monitored by the use of the flexible membrane 159. The passage of fluid can be controlled through the actuation of the first valve 164, the second valve 167, the third valve 166 and the fourth valve 165. To fill the second section 161 of the chamber 158 and empty the section 160 of the chamber 158, the first valve 164 and the second valve 167 are closed while the third valve 166 and the fourth valve 165 are opened. This pushes the diaphragm or membrane 159 to the upper side of the chamber 159 as shown in Figure 57. As illustrated in Figure 58, this process can be reversed to fill the first section 160 and empty the second section 161 by opening the first valve 164 and the second valve 167 while closing the third valve 166 and the fourth valve 165. Since the volume of the chamber 158 is known, the volume of fluid flowing through the inlet port 162 to the outlet port 163 can be estimated by the movement of the membrane because the membrane 159 is expected to become flush against the inner surface of the chamber 158.

[000523] To determine when the membrane 159 (i.e., diaphragm) has reached the top or bottom of the chamber 158, a pressure sensor could be added to the inlet valve 162. When the membrane 159 reaches the end of the path, the flow of the Input port 162 will be occluded and pressure will increase. At this point, the valves can be switched (as shown in Figure 58) and the process continued in the opposite chamber.

[000524] In some embodiments of the present description, valves 164, 165, 166 and 167 can be switched mechanically. The inlet pressure 162 could potentially be used to mechanically toggle a switch that alternately opens and closes the two pairs of valves in each state as illustrated by Figures 56 through 57 or Figure 58. For example, the inlet pressure could expand a spring-loaded diaphragm that pushes on a locking mechanism that controls valves 164, 165, 166, and 167.

[000525] Additionally or alternatively, in some embodiments, the chamber 158 may be made of a clear material (polycarbonate, topaz, etc.) and the diaphragm 159 of an opaque material and a camera may be used to observe the chamber 158 and detect when diaphragm 159 reached the end of its path. In yet another embodiment, a "target" image could be placed on diaphragm 159 and a pair of stereo cameras (not shown) could detect when that target has reached the edge of chamber housing 158 and is viewable. For example, there may be one camera for viewing the first section 160 from the outside and another camera for viewing the second section 161 from the outside.

[000526] Figure 59 shows a diagram of a disposable portion 168 of a flow meter in accordance with an embodiment of the present description. The disposable portion 168 may be part of the flow meter 10, 11 or 12 of Figure 1, the flow meter 169 of Figure 2 for use within the infusion site monitor 26, or it may be the flow meter 48 of Figure 3 for use with pump 19 (in some embodiments, flow meter 48 is coupled to tube 56). In still further embodiments, the disposable portion 168 is part of an integrated flow rate meter and membrane pump. The disposable portion 168 may interface with an upper hinge valve Acoustic Volume Sensing (AVS) assembly and a lower hinge valve AVS installation (e.g., the upper hinge valve AVS installation 192 and the lower hinge valve AVS installation 193 of Figure 70 as described below). Acoustic volume detection is described in greater depth in the detailed description section titled "ACOUSTIC VOLUME DETECTION"

[000527] The disposable portion 168 includes inlet tubing 170, an inlet occluder release collar 171, an inlet duckbill occlusion valve 172, a disposable body 173, fluid routes 174 and 181, a AVS 175 (described below), a spectral analysis and air purge window 176, and an outlet facility 177. The outlet facility 177 includes an occlusion valve 178, a release collar 179, and an outlet tubing 180.

[000528] Duckbill valves 172 and 178 can be actuated open by deforming the duckbill (pinching the groove) when the AVS hinge valves (see Figure 70) are closed over the AVS fluid chamber 175 and/or There may be separate components in the pipeline established to open the valves 172 and 178 manually (e.g., sliding an oval ring over the duckbill to open the same, etc.).

[000529] The AVS chamber 175 can be used to measure fluid flowing through the disposable portion 168. That is, the AVS system described below can measure the volume of fluid within the AVS chamber 175. The flow rate can be communicated by a processor to the monitoring client 6, for example, via a wired or wireless connection. The measurement taken by the AVS chamber 175 may be operatively communicated to a processor, e.g., the processor 37 of the infusion site monitor 26 of Figure 2 or the processor 38 of the pump 19 of Figure 3 to control the measurement of flowing fluid. through the AVS 175 camera.

[000530] Referring to Figures 1 and 59, the disposable portion 168 can be used (with the complete AVS hinge valve installation described below) to control the flow of pumps 19, 20, and/or 21 (directly or via of a control system within the monitoring client 6) or may be used to indicate when a predetermined amount of fluid has been fed to the patient 5, in which case a signal is sent to pumps 19, 20 and/or 21 to stop the flow of fluid (directly or through a control system within the monitoring client 6). In some embodiments, the disposable portion 168, when used as a flow meter with the complete AVS hinge valve installation, may be used to run a pump in a fixed volume mode with a variable fill and/or empty time, may be used to run at a variable volume with a fixed and/or variable filling or emptying time or can be run at a fixed measuring interval, etc. Additionally or alternatively, the disposable portion 168 may detect error conditions or leakage conditions (e.g., fluid is flowing beyond a predetermined threshold) that may be used to cause the flow rate meter using the disposable portion to 168 issues an alarm or alert, for example, directly or to the monitoring client 6. The alarm or alert can be used to cause one or more of the valves 16, 17, 18 and/or 25 to prevent the flow of fluid additional.

[000531] Referring again to Figure 59, the disposable portion 168 may be formed by two or more sheets of barrier film or layers of the barrier film and a rigid plastic sheet that are heat sealed together. The disposable portion 168 may be used with (or is part of) the disposable portion 194 of Figures 60 to 62, the disposable portion 201 of Figures 63 to 65, the disposable portion 208 of Figures 66 to 68, and the disposable portion 220 of Figure 69. Fluid pathways may be incorporated into the film and/or rigid plastic (e.g., they may be thermally formed or simply an area of the film that is not heat sealed). For example, the rigid portion may define fluid routes 174 and 181 and the AVS chamber 175; and a flexible layer may be placed on the rigid sheet so that the flexible layer is generally flat when in an unpressured state on the rigid layer.

[000532] For example, the disposable portion 168 may be formed from three layers using a rigid plastic sheet with a barrier membrane/film on both sides that contains the fluid routes routed in one of (or both) ) sides connected by through hole(s) in the rigid plastic sheet (e.g., a "via").

[000533] The AVS chamber 175 may be embedded in film and/or rigid plastic (e.g., thermally formed or simply an area of the film that is not heat sealed; i.e., the chamber expands with elastomeric potential when filled) . Fluid can be routed to the AVS 175 chamber via the fluid routes in the film/membrane, for example, when using the three-layer design. For example, the AVS chamber 175 may be fed through holes in the AVS chamber 175 with fluid routes 174 and 181 on the opposite side. In some embodiments, these holes are part of a valve system that functions in fluid routes on the opposite side. Tubes 170 and 180 may interface fluid routes 174. Tubes 170 and 180 include normally closed occlusion valves 172 and 178, respectively. Additionally or alternatively, in some embodiments of the present disclosure, the occlusion valves 172 and/or 178 may be one-way valves.

[000534] The spectral analysis and air purge window 176 may be transparent for spectral imaging and/or analysis of the composition of the fluid contained therein. For example, the spectral analysis window 176 may be used by a camera to detect blood therein or to determine the spectral absorption or reflection of material therein which is compared to a database to determine the likely composition of the fluid and/or a concentration of a material.

[000535] The air purge 176 may include a microporous hydrophobic membrane that has one side in contact with the infused fluid and the other side is exposed to atmospheric air. The microporous hydrophobic membrane may be located, in some specific embodiments, in a pressurized section of the flow path. The air purge and spectral analysis window 176 may include an integral air bubble trap to prevent free flow of bubbles and/or pressure may drive collected bubbles through the membrane as fluid passes through the trap, etc.

[000536] The disposable portion 168 may optionally include various alignment features 182, which may be ink markers, holes, indentations, or other alignment feature(s). The disposable portion 168 may be constructed using stamping, vacuum forming, and heat sealing and may use materials known to be compatible with infusion fluids, e.g., IV bag materials, polycarbonates, Topaz, etc.

[000537] Figures 60 to 62 show various views of a single-sided disposable portion 194 of a flow meter in accordance with an embodiment of the present description. Figure 60 shows a side view of the disposable portion 194 of a flow meter, Figure 61 shows a top view of the disposable portion 194 of the flow meter, and Figure 62 shows an end view of the disposable portion 194 of the flow meter.

[000538] The disposable portion 194 includes one or more layers of film 195 that define a fluid space 196 with a lower film 197 that may be rigid (in some embodiments, the lower film 197 is semi-rigid or flexible). As is readily seen in Figure 61, the film 195 also forms an AVS chamber 198. As seen in Figure 62, the AVS chamber 198 is positioned to measure fluid flowing into and out of the AVS chamber 198 through of the fluid path 199. The fluid path 199 interfaces with the AVS chamber 198 which allows it to expand as fluid enters the AVS chamber 198 from the fluid path 199. The fluid path 199 can retain a volume of, in some specific embodiments, 0.025 cm3 allowing a maximum flow rate of 300 milliliters per hour. The layers 195 are heat bonded along the length 200.

[000539] As shown in Figure 62, the fluid path 199 formed by layer 195 is visible and the AVS chamber 198 is also visible; however, layer 195, in some embodiments, passes from the fluid route 199 to the AVS chamber 199 by passing from the left side of the disposable portion 194 to the right side as shown in Figure 61. For example, in Figure 62, the layer fluid route 199 is relatively proximal (along a length 284 of Figure 61) to the AVS chamber 198 (which is along a length 285 of Figure 62), which is distal in the view shown in Figure 62.

[000540] Figures 63 to 65 show various views of a two-sided disposable portion 201 of a flow meter in accordance with an embodiment of the present description. The disposable portion 201 includes one or more upper films 202 with one or more lower films 203 that together define a fluid space 204. Any of the films 202 and/or 203 may be rigid, semi-rigid, flexible or elastic. In additional specific embodiments, a rigid, flat layer may be positioned between layers 202 and 203 (not pictured) with layers 202 and 203 being flexible.

[000541] As is easily seen in Figure 64, films 202 and 203 form an AVS chamber 205. As is easily seen in Figure 65, the AVS chamber 205 can measure fluid received from a fluid path 206. Also, fluid may exit the AVS chamber 205 via the fluid route 206. As also shown in Figure 65, the bonded and/or heat-sealed interface 207 is shown. As mentioned, in some embodiments, a rigid member (not shown) may be placed in the center of layers 202 and 203 thereby defining two AVS chambers 205 and two fluid paths 206; In this specific embodiment, a small hole may exist between the two fluid routes 206 and/or the two AVS chambers 206 to provide pressure equalization therebetween. Any common mode compliance of the fluid path 206 would be considered by one of the AVS chambers 205 thus providing a self-balancing of the AVS measurements.

[000542] Figures 66 to 68 show various views of a three-layer opposite-side disposable portion 208 of a flow meter in accordance with an embodiment of the present description. The disposable portion 208 is formed by a top layer 209 and a bottom layer 212 that have a rigid plastic layer 210 between them. The rigid plastic layer 210 has two holes 217 and 218 that allow fluid to pass between a fluid space 211 and the AVS chamber 213.

[000543] Fluid passes from fluid path 215 through holes 217 and 218 to transgress through AVS chamber 213. Also, disposable portion 208 includes a heat-bonded portion 219.

[000544] Figure 69 shows a top view of another disposable portion 220 of a flow meter in accordance with another embodiment of the present description. The disposable portion 220 includes one or more layers attached to a rigid body 259. The rigid body 259 includes an interruption portion 260. The AVS chamber 261 may project outward from both sides of the rigid body 259 allowing an AVS installation (not shown) surrounding the AVS chamber 261 estimate the volume of the AVS chamber 261. Air can completely pass through the stop portion 260 so that a varying volume can be positioned completely (or substantially) around the interruption chamber. AVS 261. The disposable portion 220 may be formed from one or more elastic layers sealed to the rigid body 259. The disposable portion 220 includes fluid routes 262 and 263 that allow fluid to transgress and exit through the AVS chamber 261.

[000545] Figure 70 shows a flow meter 221 that includes a complete AVS hinge valve installation and a single-sided disposable portion (e.g., the disposable portion 194 of Figure 62) in accordance with an embodiment of the present description. The 221 flow meter can fill 0.025 cm3 of liquid to up to 300 millimeters per hour.

[000546] AVS hinge valve installation includes installation of upper AVS hinge valve 192 and installation of lower AVS hinge valve 193. Installation of lower AVS hinge valve 192 can be slightly oriented for proper seating on lower support 233 and/or or may include a rigid plastic sheet or reinforcement to supplement the vents 224. The upper and lower AVS hinge valve installations 192 and 193 may circumferentially surround the AVS fluid volume 224, e.g., just the outside of the heat seal. with the use of a through/protrusion "clamp"; and an O-ring may also be optionally used to seal the fluid volume AVS 224. The flow meter 221 may optionally include an air sensor as described herein, e.g., camera-based air sensor and/or or ultrasonic, to determine whether air beyond a threshold is being delivered to a patient; an alarm or alert may be issued in response to air exceeding the threshold. Additionally or alternatively, air may be subtracted from the volume of liquid estimated to flow through the flow meter 221.

[000547] The flow meter 221 includes an AVS reference chamber 222, a reference microphone 223, a resonance port 224, an integral perimeter valve or seal 225 (shown in the open state), another integral perimeter valve or seal 230 (shown in the sealed state), a variable volume microphone 226, a speaker 227, and a variable volume 228. The flow meter 221 also includes a spring disk 229. The spring disk 229 may include a small hole for pressure equalization. The spring disc 229 may be formed, in some embodiments, of an elastomeric layer or film. In some embodiments, the spring disk 229 is used to introduce fluid into the AVS fluid volume 224. The spring disk 229 may provide a spring through preforming and/or the variable volume 228 may have a negative pressure or positive relative to either the ambient air and/or the fluid flowing through the AVS 224 fluid volume.

[000548] Valves 225 and 230 slide along the body of the upper AVS hinge valve installation 192 to allow or occlude fluid from entering or leaving the AVS fluid volume 224. Valves 225 and 230 are coupled to an actuator (e.g. example, linear stepper motor, linear servo, a cam follower coupled to a rotating cam, etc.) to control the valve states of valves 225 and 230. Valves 225 and/or 230 may: be normally closed; actuated open (for example, using a solenoid and/or Nitinol); include a position sensor; cone-shaped (e.g., a cone-shaped plunger on the fluid route side pushes through the elastomer into AVS chamber inlet/outlet holes to form a seal); and may include an opposing pressure seal to determine whether the valve is applying sufficient pressure. The actuators may be coupled to a processor disclosed herein (e.g., the processor 37 of Figures 2 or 3). Valves 225 and/or 230 may both close on an error condition to prevent fluid from being sent to a patient, for example, when the processor 37 of Figures 2 or 3 and/or the monitoring client 6 determines that a condition error exists that requires stopping the flow of fluid to the patient. The processor may coordinate the operation of valve 225 and 230 so that the volume AVS 226 is filled when, for example, a pulsation pump pumps liquid downstream. The flow rate meter 221 may coordinate its operation with a pump, for example, via wireless information received from the pump, such as a flow rate, pulse times, pulse durations, pulse volumes, pulse frequency. , etc.

[000549] Speaker 227 emits one or more acoustic frequencies that are received by reference microphone 223 and variable volume microphone 226. The acoustic gain between microphones 223 and 226 can be correlated to the volume of variable volume 228 to determine the volume through the flow rate meter 221. Additionally or alternatively, the phase shift between microphones 223 and 226 may be correlated to the volume of the variable volume 228. The speaker 227 and microphones 223 and 226 may be in communication functional with one or more processors to implement an algorithm for determining volume using the AVS, e.g., processor 37 of Figures 2 or 3. Additional details relating to the operation of the AVS are described below in the section entitled "DETECTION OF ACOUSTIC VOLUME".

[000550] Films 231 and 233 define a fluid space 232. As the fluid varies within the AVS fluid volume 224 entering and exiting through the fluid space 232, the difference in volume is calculated to determine the flow rate per flow meter 221. That is, the variable volume 228 has an acoustic response that can be used to determine the volume of fluid AVS 224. The flow meter 221 also includes ventilation paths 225 to prevent air from building up under the film 233 which defines the fluid volume AVS 224.

[000551] In yet a further embodiment of the present description, the flow rate meter 221 can be used as part of a membrane pump. For example, an actuator (not shown) may interface with the spring disk 229 (or film 231) to provide a pumping action with the fluid volume AVS 224; the actuator may exist within the variable volume or may interface with the spring disc 229 via a shaft that transgresses through the upper hinge valve installation 192 (with an appropriate acoustic seal). Shaft volume can be considered in the AVS measurement and/or the entire actuator can be at variable volume.

[000552] Figure 71 shows a side view of a flow rate meter 234 that includes an upper AVS installation 236 and a lower AVS installation 238 with integral perimeter seal valves 239 and 340 in accordance with an embodiment of the present description . The flow rate meter 234 may include the disposable portion 201 of Figures 63 through 65. The flow rate meter 234 may allow flows of up to 0.25 cm per fill for up to 300 millimeters per hour, in some specific embodiments, for example. example, 0.125 cm3 for each side for 150 millimeters per hour on each side.

[000553] The upper AVS installation 236 measures the acoustic response of the upper variable volume 241 and the lower AVS installation 238 measures the acoustic response of the lower variable volume 242. Measurements of the acoustic response of the upper and lower variable volumes 241 and 242 can be correlated to the upper and lower variable volumes 241 and 242. The volume of the AVS fluid chamber 243 can be estimated by subtracting a predetermined total volume from the volumes of the AVS chambers 241 and 242. A processor disclosed herein (e.g., processor 37 of the Figures 2 or 3) can estimate the volume of the AVS 243 fluid chamber.

[000554] In yet a further embodiment of the present description, the flow rate meter 234 can be used as part of a membrane pump. For example, one or more actuators (not shown) may interface with the spring disks 235 and/or 237 (or the AVS fluid chamber 243) to provide a pumping action with the AVS fluid volume 243; the actuator may exist within the variable volumes 243 and/or 242 or may interface with the spring discs 235 and/or 237 via a shaft that transgresses through the AVS installations 236 and/or 238 (with an appropriate acoustic seal). . Shaft volume can be considered in the AVS measurement and/or the entire actuator can be at variable volume.

[000555] Figure 72 shows a side view of another flow rate meter 244 that includes a single-sided AVS assembly 245 with variable surrounding volumes 246 and 2 in accordance with another embodiment of the present description; The flow rate meter 244 may use the disposable portion 220 of Figure 69. The variable volumes 246 and 247 may be in fluid communication with each other around the edges of the AVS fluid chamber 248. The AVS facility 245 measures acoustic response of chambers 246 and 247 to correlate the volume of AVS chambers 246 and 247. The total volume of AVS chambers 246 and 247 is subtracted from the predetermined total volume to estimate the volume of fluid within the fluid volume of AVS 248.

[000556] In yet another embodiment of the present description, the flow rate meter 244 can be used as part of a membrane pump. For example, one or more actuators (not shown) may interface with the spring disks 286 and/or 287 (or the AVS fluid chamber 248) to provide a pumping action with the AVS fluid volume 248; the actuator may exist within the variable volumes 246 and/or 247 or may interface with the spring discs 286 and/or 287 via a shaft passing through the AVS installation 245 (with an appropriate acoustic seal). Shaft volume can be considered in the AVS measurement and/or the entire actuator can be at variable volume.

[000557] Figure 73 shows a side view of yet another flow rate meter 249 that includes two piston valves 250 and 251 in accordance with another embodiment of the present description. Piston valves 250 and 251 may be coupled to actuators which are in turn coupled to a processor, e.g., processor 37 of Figures 2 or 3. Flow rate meter 249 includes an AVS hinge valve installation. upper 252 and a lower AVS hinge valve installation 253. Fluid flows from the fluid route 254, through a hole 255 and into the AVS fluid chamber 256. Therefore, fluid can flow through the hole 257 (when the valve 251 is in the open state, through the fluid route 258) and finally out of the flow rate meter 249. The piston valves 250 and/or 251 may alternately close and open such that one of the piston valves is open while that the other is closed. The spring disc 229 can assist in ingress of fluid into or expulsion of fluid out of the AVS 256 fluid chamber.

[000558] In yet a further embodiment of the present description, the flow rate meter 249 can be used as part of a membrane pump. For example, one or more actuators (not shown) may interface with the spring disk 288 (or the AVS fluid chamber 257) to provide a pumping action with the AVS fluid volume 257; the actuator may exist within the variable volume 289 or may interface with the spring disc 289 via a shaft that transgresses through the AVS installation 252 (with an appropriate acoustic seal). Shaft volume can be considered in the AVS measurement and/or the entire actuator can be at variable volume.

[000559] Figure 74 shows a flow rate meter 259 that has upper and lower AVS facilities (262 and 263, respectively) that provide a semi-continuous flow in accordance with an embodiment of the present description. The flow rate meter 259 includes valves 260, 261, 264, and 265. The valves 260, 261, 264, and 265 may operate together to fill a volume of AVS fluid 266 and 267 in a sequential but opposite manner. For example, valves 260, 261, 264, and 265 may operate to fill fluid volume AVS 266 while discharging the other fluid volume AVS 267 and vice versa. That is, when one volume of AVS fluid is being filled, the other volume of AVS fluid may have an AVS measurement taken by the respective AVS installation.

[000560] The flow rate meter 259 also includes a small reservoir 268 for storing fluid flowing from a pump and a variable occluder 269 that can be coupled to a processor. The variable occluder 269 can be varied so that the discharge of the AVS fluid volumes 266 and 267 is "smoothed" to produce a semi-continuous flow to the patient (e.g., the AVS fluid volumes 266 and 267 can be spring loaded, such as a disc spring, to force the fluid out). The processor may use feedback from the AVS facilities 262 and 263 to adjust the variable occluder 269 to achieve a target flow rate for a patient.

[000561] In a specific embodiment, the flow rate meter 259: measures flow over a range of 0.1 to 300 ml/h; allows unmetered flow rates of more than 300 ml/h to 2,000 ml/h; flow resistance does not exceed 6.89 kPa (1 PSI) over a flow range of 0.1 to 2,000 ml/h; active volume accumulation does not exceed 2 millimeters; has a retention volume of less than 0.5 ml; has a size of less than 25.4 centimeters (1 inch), by 76.2 centimeters (3 inches), by 25.4 centimeters (1 inch) for disposable; can be powered by battery or wire and can run at a rate of 100 ml/h for 8 hours on battery power; and may include a user interface that communicates with all valves, sensors and components wirelessly.

[000562] Figure 75 shows a flow rate meter 276 having two in-line AVS installations 270 and 271 with a plurality of valves 272, 273, 274, 275 and 277 for controlling the fluid flowing therethrough in accordance with an embodiment of this description. Valve 275 allows the least amount of fluid flow to AVS volume 279 from AVS volume 278, valve 274 allows the most fluid to flow to AVS volume 279 from AVS volume 278, and valve 273 allows the greatest amount of fluid to flow to AVS volume 279 from AVS volume 278. Valves 273, 274 and 275 can be controlled to control flow from the pump to the patient.

[000563] The two installations AVS 270 and 271 can each take measurements of the fluid volumes AVS 278 and 279, respectively. AVS 278 and 279 fluid volumes may be different because of a pressure difference caused by valves 273, 274 and 275 as fluid flow from the pump to the patient. Continuous fluid flow causes a difference in pressure based on Bernoulli's principle.

[000564] A continuous flow sensor can use the Bernoulli principle. For example, a fixed orifice or other restriction in a fluid flow path (e.g., one caused by an orifice plate) can be used to measure a pressure drop across the orifice to determine the flow rate based on the Bernoulli principle illustrated in Equation (33) as follows: where Q is the volumetric flow rate, Cd is the discharge coefficient which refers to the turbulence of the flow, p is the density of the fluid, A1 is the cross-sectional area just in front of the restriction, A2 is the cross-sectional area cross section of the restriction and Δp is the pressure drop across the restriction. Equation (33) can be simplified to Equation (34) as follows:

[000565] Ao is the orifice area and Cf is a constant related to turbulence and geometry specific to the restrictor design (Cf typically has a value between 0.6 and 0.9 that is empirically derived). Therefore, the estimated flow rate is related to the orifice area and the square root of the measured pressure drop. The estimated flow rate is also related to the density of the fluid being measured and the orifice geometry.

[000566] Therefore, valves 273, 274, and 275 of flow meter 276 can be considered a restrictor (e.g., serving as an orifice plate in a continuous flow rate meter) to produce a measurable pressure difference between the AVS volumes 278 and 279. AVS volumes 278 and 279 can be correlated with respective pressures because the respective membranes that form AVS chambers 278 and 279 will stretch based on the pressure therein.

[000567] For example, valves 272 and 277 can be opened thereby allowing fluid to flow continuously from the pump to the patient. AVS volumes 278 and 279 will have a difference in pressure caused by the total restriction of one or more of valves 273, 274 and 275 (which may, in some embodiments, be modeled as an orifice).

[000568] Differential AVS volume measurements between AVS chambers 278 and 279 are proportional to the flow rate (the pressure difference can be correlated to the flow rate empirically). Any common mode downstream pressure change would result in a volume increase in both AVS chambers 278 and 279 thus subtracting the increase in AVS chambers 278 and 279. Additionally, a predetermined positive change in AVS volume measurements may be considered. an indication of an occlusion and a predetermined change in flow rate can trigger an alarm and/or alert.

[000569] Valves 273, 274, and 275 allow a range of flow rates from the pump to the patient to be used and also change the measurement range of the flow rate meter 276. A processor may actuate one or more valves 273, 274 and 275 and can determine the total restriction of occlusion caused by valves 273, 274 and 275. That is, the configuration of valves 273, 274 and 275 can be correlated to a model, e.g., a cross-sectional area of a restriction using Equation (33) or (34) to determine the flow rate. The processor may vary valves 273, 274, and 275 to determine the flow rate within a desired measurement flow rate range.

[000570] The AVS 270 and 271 installations perform a measurement within a predetermined amount of time by sweeping the acoustic frequencies (as described herein), for example, for half a second or 1/20 of a second. In some embodiments, the AVS installations 270 and 271 may perform two types of frequency sweeps, e.g., a shorter frequency sweep (e.g., performed in less time) and/or a full frequency sweep, e.g., to perform another error check such as, for example, to check for acoustic leak(s). The flow rate meter 276 may, in some embodiments, coordinate with a pump to introduce a periodic disturbance to calibrate the flow meter 276 and/or for error checking. Additionally or alternatively, small reservoirs 400 and 401 may provide fluid damping to "smooth" the flow in some embodiments. Fluid reservoirs 400 and 401 may be formed from an elastic material that defines a flexible bubble-type bladder.

[000571] Valves 272 and 277 can have their operation coordinated to check for error conditions. For example, valve 272 may be closed while valve 277 remains open to determine whether fluid is being discharged to the patient for error checking (e.g., to check for occlusions, etc.).

[000572] In some embodiments, valves 272, 273, 274, 275 and 277 are used so that AVS volumes 278 and 279 are operated such that one of the AVS volumes is filled with a liquid while the other AVS volume discharges the liquid thereby providing continuous piecewise flow measurements using AVS volumes 278 and 270. Additionally or alternatively, valves 272, 273, 274, 275 and 277 can also be used to do a "flow to zero" test to make a "zero flow" correction (e.g., correct for volume drift from AVS volume measurements).

[000573] In a specific embodiment, the flow rate meter 276: can measure continuous flow over a range of 0.1 to 300 ml/h (in some embodiments, up to 2,000 ml/h); has a measurement accuracy of +/- 0.02 ml/h 0.1 to 2.5 ml/h or 5% otherwise; measures fast enough to be insensitive to flow disturbances from a 10% change in flow in 1 second; measures with head height pressure changes of +/- 13.79 kPa (2 PSI); does not add flow resistance that exceeds 6.89 kPa (1 PSI) over a flow range of 0.1 to 2,000 ml/h; has a size of less than 25.4 centimeters (1 inch), by 76.2 centimeters (3 inches), by 25.4 centimeters (1 inch) for disposable; can be battery powered or corded and can run at a rate of 100 ml/h for 8 hours on battery power; and may include a user interface that communicates with all valves, sensors and components wirelessly.

[000574] Figure 76 shows a membrane pump 280 that has a negative pressure source 281 in accordance with an embodiment of the present description. The membrane pump 280 includes valves 282 and 283 that can alternate between applying a negative pressure to the variable volume 290 and applying atmospheric pressure to the variable volume 290. The valves 282 and 283 are fluidly connected to the reference volume AVS 402 through of a port 403 that is of a sufficiently small size that does not introduce acoustic artifacts, e.g., 0.508 millimeters (0.020 inches) in some specific embodiments. A processor, e.g., processor 37 of Figure 3, may control valves 282 and/or 283 to achieve a target pressure within reference volume 402 as measured by a pressure sensor 404. The processor, e.g., the processor 37 of Figure 37 of Figure 3, may be in functional communication with valves 282 and 283 and with pressure sensor 404.

[000575] Valve 282 may be closed and valve 283 may be opened thereby placing the variable volume 290 in fluid communication with the negative pressure source 281. Therefore, valve 283 may be closed and valves 282 opened to place the variable volume 2190 in fluid communication with atmospheric air. This may be repeated continuously to repeatedly oscillate the pressure within the variable volume 290. In some specific embodiments, AVS measurements are made when the variable volume 402 is placed in a state of static pressure (e.g., set at ambient pressure, negative pressure static pressure or closing valves 282 and 283) and the fluid volume AVS 293 is placed in a state of static pressure (e.g., piston valves 291 and 292 are closed).

[000576] As mentioned previously, a negative source 281 can be applied to the variable volume 290 by opening the valve 283 and closing the valve 282. When negative pressure is applied to the variable volume 290, the piston valve 291 can be opened and the piston valve 292 closed to draw fluid into the fluid volume AVS 293. Therefore, the valve 283 and the piston valve 291 are closed so that an AVS measurement can be taken by the AVS installation 249 (the AVS installation 294 includes a lower AVS hinge valve installation 296). Optionally, piston valves 291 and 292 can be closed before or during the AVS measurement. Therefore, valve 282 and piston valve 292 are opened to allow fluid to flow into fluid channel 295 from AVS chamber 293. Next, piston valve 292 and valve 282 are closed and another measurement AVS is taken from AVS chamber 293. The difference in these AVS measurements can be correlated to the amount of fluid pumped for each respective pumping cycle. That is, each pulse for the patient can be estimated by subtracting one AVS measurement from another AVS measurement. In some specific embodiments, the AVS measurements are each taken at the same pressures as the AVS volume 290 (e.g., at atmospheric pressure or at a static negative pressure, as may be determined by the pressure sensor 404) to account for the effects of positive and negative pressures on the air bubble volume thereby mitigating the effect that an air bubble has on fluid volume flow measurements.

[000577] Figure 77 shows a membrane pump 300 that has a negative pressure source 296 and a positive pressure source 297 coupled to valves 298 and 299, respectively, in accordance with an embodiment of the present description. The negative pressure source 296 may be in fluid communication with the variable volume 301 when drawing fluid into the AVS chamber 302. Likewise, the positive pressure source 297 may be in fluid communication with the variable volume 301 when discharging the fluid out of the AVS chamber 302. The variable volume may be coupled to atmospheric pressure 303 via a valve 304 when an AVS measurement is taken.

[000578] It should be noted that no disc spring is used in the embodiment shown in Figure 77. The fluid volume AVS 302 is formed from a flaccid material that generates little or no pressure within the variable volume 301. In some embodiments of the present description, pump 300 takes AVS measurements all at the same pressure to account for pressure effects on bubble size; for example: AVS volume measurement can be taken as follows: (1) close piston valve 405, open piston valve 406, open valve 298, close valve 299 and close valve 304 thereby causing the fluid is drawn into the AVS chamber 302 with negative pressure from the negative pressure source 296; (2) close piston valve 406 and close valve 298; (3) opening valve 304, thereby causing the pressure of the variable volume 301 to reach atmospheric pressure 303; (4) close valve 304; (5) take an AVS measurement; (6) opening valve 299 and opening piston valve 405 thereby discharging fluid out of AVS volume 302; (7) close piston valve 405 and close valve 299; (8) opening valve 304 to equalize the variable volume pressure to atmosphere 303; (9) close valve 304; (10) take an AVS measurement; (11) and compare AVS volume measurements to determine volume discharged, e.g., to estimate flow rate. The previous example can be modified to take one or more AVS measurements at positive pressure, negative pressure, atmospheric pressure, or some combination thereof.

[000579] In a still further embodiment, the positive pressure source 297 is used to take AVS measurements when the variable volume 301 is under a positive pressure. For example, in some embodiments of the present disclosure, pump 300 takes AVS measurements all at positive pressure to account for pressure effects on bubble size; for example: the AVS volume measurement can be taken as follows: (1) close piston valve 405, open piston valve 406, open valve 298, close valve 299 and close valve 304 thereby causing the fluid is drawn into the AVS chamber 302 with negative pressure from the negative pressure source 296; (2) close piston valve 406 and close valve 298; (3) opening the valve 299 thereby causing the pressure of the variable volume 301 to reach a predetermined positive pressure as indicated by the pressure sensor 407; (4) close valve 299; (5) take an AVS measurement; (6) opening the valve 304 and opening the piston valve 405 thereby discharging the fluid out of the AVS volume 302; (7) close piston valve 405 and close valve 304; (8) opening the valve 299 thereby causing the pressure of the variable volume 301 to reach a predetermined positive pressure as indicated by the pressure sensor 407; (9) close valve 299; (10) take an AVS measurement; (11) and compare AVS volume measurements to determine volume discharged, e.g., to estimate flow rate. The previous example can be modified to take one or more AVS measurements at positive pressure, negative pressure, atmospheric pressure, or some combination thereof.

[000580] Pump 300 can also, in some embodiments, determine whether there is compliance in the system, such as compliance caused by air, by taking AVS volume measurements at two different pressures. For example, two AVS measurements may be taken during the fill phase at two different pressures (e.g., negative pressure and ambient pressure or some other combination) and/or during the discharge phase at two different pressures (e.g., negative pressure and ambient pressure or some other combination). The change in volume at the two pressures can be correlated with AVS 302 volume compliance, such as if there is an air bubble in the fluid. If a predetermined amount of AVS 302 volume variation is determined to exist, a processor may determine that an error condition exists and issue an alarm or alert. In yet another embodiment, the flow rate measurement may be corrected for the taken air volume measurement; For example, a processor may determine the volume of air that was delivered to the patient instead of a drug such as insulin and compensate for insulin delivery to ensure that the prescribed dose of insulin is delivered. For example, consider the following additional modalities.

[000581] In some embodiments of the present disclosure, compliance can be estimated in pump 300 by taking at least two AVS measurements at different pressures to account for air bubbles; for example: AVS volume measurements can be taken as follows: (1) close piston valve 405, open piston valve 406, open valve 298, close valve 299, and close valve 304 thereby causing the fluid is drawn into the AVS chamber 302 with negative pressure from the negative pressure source 296; (2) close piston valve 406 and close valve 298; (3) taking an AVS measurement while reference volume 301 remains under negative pressure; (3) opening valve 304, thereby causing the pressure of the variable volume 301 to reach atmospheric pressure 303; (4) close valve 304; (5) taking an AVS measurement while reference volume 301 remains at atmospheric pressure; (6) compare the two AVS measurements from (3) and (5) to determine AVS 302 volume compliance; (7) opening the valve 299 and opening the piston valve 405 thereby discharging the fluid out of the AVS volume 302; (8) close piston valve 405 and close valve 299; (9) taking an AVS measurement while variable volume 301 remains under positive pressure; (10) opening valve 304 to equalize the variable volume pressure to atmosphere 303; (11) close valve 304; (12) taking an AVS measurement while the variable volume 302 remains under atmospheric pressure; (13) compare the two AVS measurements of (9) and (12) to determine AVS 302 volume compliance; (14) and compare at least two AVS volume measurements to determine the volume discharged, for example, to estimate the flow rate. The above example can be modified in several ways so that the two AVS measurements that have two different pressures and can occur during the fill stage, discharge stage, any other stage of pumping, with the use of one or more of a measurement positive pressure measurement, a negative pressure measurement, an atmospheric pressure measurement, or some combination thereof.

[000582] Another modality must be considered: the AVS measuring volume and the pumping action can occur as follows: (1) close the piston valve 405, open the piston valve 406, open the valve 298, close the valve 299 and close valve 304 thereby causing fluid to be drawn into the AVS chamber 302 with negative pressure from the negative pressure source 296; (2) close piston valve 406 and close valve 299; (3) taking an AVS measurement when variable volume 301 remains at negative pressure; (4) opening the valve 299 thereby causing the pressure of the variable volume 301 to reach a predetermined positive pressure as indicated by the pressure sensor 407; (5) close valve 299; (6) taking an AVS measurement when variable volume 301 is at positive pressure; (7) compare the two AVS measurements from (3) and (6) to determine AVS 302 volume compliance; (8) opening the valve 304 and opening the piston valve 405 thereby discharging the fluid out of the AVS volume 302; (9) close piston valve 405 and close valve 304; (10) taking an AVS measurement while the variable volume 301 is at atmospheric pressure (in another embodiment, the AVS measurement volume is taken at negative pressure); (11) opening the valve 299 thereby causing the pressure of the variable volume 301 to reach a predetermined positive pressure as indicated by the pressure sensor 407; (12) close valve 299; (13) take an AVS measurement; (14) and compare across two AVS volume measurements to determine volume discharged and/or variable volume compliance, e.g., to estimate flow rate. The example above can be modified in several ways so that two AVS measurements that have two different pressures can occur during the filling stage, discharge stage, any other stage of pumping, with the use of one or more of a positive pressure, a negative pressure measurement, an atmospheric pressure measurement, or some combination thereof.

[000583] In a specific embodiment, the membrane pump 300: has a target flow rate of 0.1 to 2,000 ml/h; can generate at least a maximum of 20.68 kPa (3 PSI) and up to 68.95 kPa (10 PSI); can pull fluid from a reservoir to a maximum negative pressure of at least -13.79 kPa (-2 PSI); can be battery powered; can be powered by a cable; and may have a user interface that communicates wirelessly with a processor coupled to all actuators, valves, pressure sensors, and other devices.

[000584] Figure 78 shows an optical sensor-based flow rate meter 305 in accordance with an embodiment of the present description. The flow rate meter 305 includes an IR source 306 that reflects light away from a flexible membrane 307. The reflected IR light is received by a sensor 308. The sensor formed by the IR source 306 and the IR sensor 308 may be a sensor with part number: GP2S60 manufactured by Sharp Corporation. Light reflected off the membrane 307 can be correlated to a volume 309. With an upstream or downstream pump (not shown) used in conjunction with inlet and outlet valves (not shown), the flow rate can be calculated measuring light as it reflects off the membrane 307. Since a change in fluid pressure in the tube results in a displacement of the elastomer membrane 309, the distance between the sensor 308 varies as a function of the pressure in the tube. fluid; therefore, the sensor output is proportional to the pressure in the fluid tube and can be correlated to pressure and/or volume.

[000585] The flow rate meter 305 can be used by a membrane pump disclosed herein to facilitate positive and/or negative pressure measurements. The pressure sensitivity can be adjusted by selecting the elastomeric properties of the membrane and the fluid contact area with the membrane forming the AVS 309 volume. The reflective property of the elastomeric membrane can be enhanced with metal, plastic, film or other material reflective. A temperature sensor may be added to account for the thermal effects of the material forming the AVS volume 309. A heat sink and/or thermal controller surrounding the elastomeric AVS chamber 309 may be used to mitigate the thermal effects, in some embodiments. specific.

[000586] The IR source 306 can be pulsed and/or multiplexing can be used with multiple IR sources 306 and multiple sensors 307 to inhibit interference error. An initial reading can be used as a zero offset and the change in sensor output can be correlated to changes in pressure in the AVS 308 volume. The focusing optics can be used with the disposable portion, e.g., the membranes, to facilitate variation and alignment of the IR source 306 and the IR sensor 308. In alternative embodiments, an ultrasonic proximity sensor is used instead of the IR source 306 and the IR sensor 308.

[000587] In a specific embodiment, the flow rate meter 305 may: have a sensitivity to pipe pressure over a range of 13.79 to +68.95 kPa (-2 to +10 PSI); can measure pipe pressure within +/-20% over a range of 6.89 to 68.95 kPa (1 to 10 PSI); have a resolution of at least 10 bits; and may be low power.

[000588] Figure 79 shows a pressure-controlled membrane pump 322 in accordance with an embodiment of the present description. Figures 80 to 82 show captions for reference in this document; that is, refer to Figures 80 to 82 for the symbol legend for Figures 83, 85, 87, 88, 90, 91, 93, 95 and 97. Referring again to Figure 79, the membrane pump 322 includes an AVS installation 323 that has a reference volume 324 and a variable volume 325. A reference volume 324 includes a speaker 326 for generating an acoustic signal in the reference chamber 324 that travels through a port 357 to the volume variable volume microphone 325. The acoustic signal is received by a reference microphone 327 and a variable volume microphone 328. The signals from the microphones 327 and 328 are compared to determine an acoustic response for measuring the volume of the AVS chamber 335. An optional optical sensor 329 can be used to reflect light off a membrane forming the AVS chamber 335. The optical sensor 329 can be used to facilitate estimation of the volume of the AVS chamber 335. In some embodiments, multiple optical sensors 329 can be used .

[000589] Pump 353 may be a diaphragm pump, such as one having part number: T3CP-1HE-06-1SNB, manufactured by Parker Hannifin Corporation located at 6035 Parkland Boulevard, Cleveland, Ohio 44124-4141; Additionally or alternatively, other pump types and/or pumps manufactured by any other manufacturer may be used.

[000590] A variable voltage applied to pump 353 (see Figure 79) can be adjusted in real time to achieve a desired pressure as measured by pressure sensor 340. Pump 353 can have a flow rate of several liters per minute. The variable volume 325 may have an air volume of 0.5 cm3 and may be pressure limited between 6.89 to 68.95 kPa (1 to 10 PSI). In some embodiments, pump 353 has a 1 Hz fill and empty cycle time and a 0.5 cm3 fluid chamber resulting in a maximum flow rate of 1,800 cm3/h, for example. In additional embodiments, the variable pressure can be controlled in bursts lasting tens of milliseconds and six aliquots can be delivered over a one-hour interval to achieve a flow rate of 0.1 cm3/h. In additional embodiments, an alternative pneumatic flow path (not shown) that has a pneumatic flow restriction can be used to reduce the working pressure in variable volume 324 thereby facilitating low and high volumetric flow ranges.

[000591] A fluid reservoir 331 is coupled via a fluid path to a one-way valve 332. The valve 332 may be a diaphragm valve. An optical sensor 333 measures when the valve is closed, for example, an optical beam may be broken when the diaphragm valve 332 is open or the optical beam is broken when the diaphragm valve 332 is closed.

[000592] Fluid moves into the AVS volume 335 through a fluid tube 334. The fluid can be discharged through a fluid path to a one-way valve 336 which is also measured using an optical sensor 337 Finally, the fluid enters a 338 patient.

[000593] The reference chamber 324 and the variable volume chamber 325 are in fluid communication with a tube 339. A pressure sensor 340 measures the pressure of the tube and therefore the chambers 324 and 325. Additionally or alternatively, the pump 322 includes a temperature sensor 330. Pressure from pressure sensor 340 and/or temperature from temperature sensor 330 can be used to increase the accuracy of AVS measurements.

[000594] Valve 341 connects tube 339 to ambient pressure 342. A pressure sensor 343 measures ambient pressure. Valve 341 is also coupled to a valve 344 which, in turn, is connected to a negative pressure source 347 and a positive pressure source 345. The positive pressure source 345 is coupled to a pressure sensor 346 and the source negative pressure sensor 347 is coupled to another pressure sensor 348. In some specific embodiments, the positive pressure source 345 and the negative pressure source 347 may be accumulators in which predetermined pressures are established therein and vented to the reference volume 324 (through valves 344, 341, 350 and 349) to develop specific pressures.

[000595] A variable flow/pressure pump 353 is coupled to both valves 349 and 350 to maintain the positive pressure reservoir 345 at a positive pressure and the negative pressure reservoir 347 at a sufficiently lower pressure. Valves 350 and 349 are coupled to atmospheric vents 354 and 351, respectively. Variable flow/pressure pump 353 is fed a signal at 356, which may be fed back to an output pin for verification by a processor, e.g., processor 37 of Figure 2. Also, a switch 355 may enable and/or disable bomb 353.

[000596] In some embodiments, the one or more optical sensors 329 may be used as part of an internal portion of a control cycle that has a target aliquot volume to deliver. For example, the one or more optical sensors 320 may provide a controller within the processor 37 of Figure 2 (e.g., a PID controller) with an estimate to fill or discharge volume based on the deflection of the membrane of the AVS chamber 335 as measured by the one or more optical sensors 329. Feedback from the one or more optical sensors 329 can be used to control pressure flow or tire timing in the AVS pump chamber, e.g., valves 231, 344, 349 and 350 .

[000597] Multiple optical sensors 329 can be used to triangulate the membrane position of the AVS chamber 335; Additionally or alternatively, the membrane may have reflective features disposed on the membrane surface of the AVS chamber 335 to provide a reflective surface for the optical sensors 329. In some specific embodiments, an external portion of the control loop may direct the delivery volume of trajectory delivered to the patient to adjust the individual aliquot volume. For example, the optical volume sensing functionality performed by the one or more optical sensors 329 may provide an independent volume measurement that is used as a check on AVS-based volume measurements and/or to calculate errors in volume estimation. In additional embodiments, only optical volume measurements are performed, that is, in this specific exemplary embodiment, no AVS is used.

[000598] Figure 83 shows a flow-controlled membrane pump 358 in accordance with an embodiment of the present description. The flow-controlled membrane pump 358 is similar to the pressure-controlled pump 322 of Figure 79; however, the flow-controlled membrane pump 358 does not have reservoirs 345 and 347 as shown in Figure 79.

[000599] Figure 84 shows state diagram 359 of the operation of the flow-controlled membrane pump 358 of Figure 83 in accordance with an embodiment of the present description. State diagram 359 includes states 360 to 368. States 360 to 368 are illustrated by Figures 85 to 98.

[000600] Referring now to Figures 84, 85 and 86, an idle state 360 is depicted in Figures 84 and 86 with Figure 86 showing further details. Idle state 360 includes substates 370 to 371. In substate 370, several variables are established. After a predetermined amount of time after substate 370 establishes the variables, substate 371 measures various values that are checked against predetermined ranges.

[000601] Figure 85 shows the flow-controlled membrane pump 358 of Figure 79 which illustrates the operation of the valves when in the idle state 360 of the state diagram of Figure 84 in accordance with an embodiment of the present description. In the idle state 360, the valve 341 couples the reference volume 324 to the atmospheric pressure source 342. Note that, as shown in Figure 85 which illustrates the idle state 360, the membrane forming the AVS volume 335 is deflated.

[000602] As shown in Figure 86, substate 370 establishes the variables PCadj, PCenbl, PCenb2, PCvl, PCv2, PCv3, HCvl and HCv2; for example, by applying an input voltage to an appropriate input (see Figure 83). Referring to Figures 85 and 86, the variable PCadj establishes the pump 353, the variable PCenbl allows input to the pump 353, the variable PCenb2 allows the switch 355, the variable PCvl controls the valve 350, the variable PCv2 controls the valve 349 , the variable PCv3 controls valve 341, the variable HCvl controls valve 332 and the variable HCv2 controls valve 336.

[000603] Also as shown in Figure 86, after the parameters are established in substate 370, substate 371 takes several measurements. In substate 371, the values of PSavs, PSatm, PCmon, OPTvar, OPThvl, OPThc2, and Tavs are taken and compared to predetermined ranges. If any of the measured values are outside a predetermined range, for example, as shown in expected column 373 in Figure 86, an error condition 372 is determined to exist; in response to error condition 372, an alert or alarm may be issued.

[000604] PSavs is a value determined from pressure sensor 340, PSatm is a value determined from pressure sensor 343, PCmon is a value determined from sensor 369 to determine if the pump is receiving the correct voltage of input voltage 356, OPTvar is a measurement from the optical sensor 329, OPThvl is the measurement from the optical sensor 333 to determine whether the valve 332 is closed or open, OPThc2 is the measurement from the optical sensor 337 to determine whether the valve 336 is closed or open and Tavs is the temperature measurement from the temperature sensor 330.

[000605] Referring again to Figure 84, after the idle state 360, the state diagram 359 continues to the positive valve leak test state 361. Figures 87 to 88 show the flow-controlled membrane pump 358 of Figure 83 in use during the positive pressure valve leak test state of Figure 84 in accordance with an embodiment of the present description. Note that there is a change in valve 349 to allow pumping of pressure to reference volume 324 from as shown in Figure 87. Figure 88 shows where valve 349 is switched again and reference volume 324 is isolated from the fluid sources.

[000606] Figure 89 shows a more detailed view of the leak test state of positive pressure valve 361 of Figure 84 in accordance with an embodiment of the present description. Figure 89 may also represent state 364 of Figure 84. Positive pressure valve leak test state 361 includes substates 374 to 380.

[000607] Substate 374 activates pump 353 and sets valves 350, 249 and 341 so that positive pressure is applied to reference volume 324. Valves 222 and 337 remain closed. In substate 374, measurements are taken. If the measured values are outside predetermined acceptable ranges, a substate 379 determines that an error condition occurs. If the Pmax mean pressure target is not reached, state 361 continues to substate 378 to wait a predetermined amount of time. This process is depicted in Figure 87. Substates 374, 375, and 378 may be repeated until a predetermined number of substates 378 occur or a predetermined amount of time is reached at which time an error substate 379 determines that an error condition exists. .

[000608] State 361 may optionally wait a predetermined amount of time when transitioning from substate 375 to 376. In substate 376, pump 353 is deactivated and valves 350 and 349 disconnect variable volume 324 from pump 353 (as depicted in Figure 88). State 361 may optionally wait a predetermined amount of time when moving from substate 376 to 377. In substate 377, various measurements are taken, such as an AVS measurement using, for example, the AVS system having speaker 326 and microphones 327 and 328 that measure the volume of the variable volume 325 (using an acoustic response) to determine whether the AVS volume 335 is changing thereby indicating a leak condition. Additionally or alternatively, the optical sensor 330 may detect whether a predetermined movement of the membrane 335 occurs to determine whether a leak condition exists. If these measurements are outside a predetermined range and/or beyond a predetermined threshold, then an error condition is determined to exist in substate 280.

[000609] Referring again to Figure 84, after the positive leak valve test state 361 occurs, a negative leak valve test state 362 occurs. Refer to Figures 90, 91, and 92 for a description of the positive leak valve 362 test state. Figures 90 through 91 show the flow-controlled membrane pump 358 of Figure 83 in use during the leak test state. of negative pressure valve 362 of Figure 84 and Figure 92 shows a more detailed view of the leak test state of negative pressure valve 362 of Figure 84 in accordance with an embodiment of the present description. As shown in Figure 92, state 362 includes substates 381 to 387. Figure 92 can also be used to illustrate state 365 of Figure 84.

[000610] Substate 381 activates pump 353 and sets valves 350, 249 and 341 so that negative pressure is applied to reference volume 324. Valves 222 and 337 remain closed. In substate 382, measurements are taken. If the measured values are outside the predetermined acceptable ranges, a substate 382 determines that an error condition occurs and continues to state 385. If the Mean Pressure Target Pmin is not reached, state 382 continues to substate 386 to wait for a predetermined amount of time. This process is depicted in Figure 90. Substates 381, 382 and 386 may be repeated until a predetermined number of substate 378 occurs or a predetermined amount of time is reached at which time error substate 385 determines that an error condition exists. .

[000611] State 362 may optionally wait a predetermined amount of time when transitioning from substate 382 to 383. In substate 383, pump 353 is deactivated and valves 350 and 349 disconnect variable volume 324 from pump 353 (as depicted in FIG. 91). State 362 may optionally wait a predetermined amount of time when moving from substate 383 to 384. In substate 383, various measurements are taken. For example, the AVS system that uses the speaker 326 and microphones 327 and 328 to measure the volume of the variable volume 325 (using an acoustic response) to determine whether the AVS volume 335 is changing, thereby indicating a condition of leak. Additionally or alternatively, the optical sensor 330 may detect whether a predetermined movement of the membrane 335 occurs to determine whether a leak condition exists. If these measurements are outside a predetermined range and/or beyond a predetermined threshold, then an error condition is determined to exist in substate 387.

[000612] Figure 93 shows the flow-controlled membrane pump 358 of Figure 83 in use during the filling state 363 of Figure 84 in accordance with an embodiment of the present description. Figure 94 shows a more detailed view of the filling state 363 of Figure 84 in accordance with an embodiment of the present description.

[000613] State 363 includes substates 388 to 391. Substate 288 establishes valves 350 and 351 and pump 353 to apply a negative pressure to variable volume 324. Valve 332 is also opened and volume AVS 335 fills with a fluid from fluid reservoir 331. State 389 takes several measurements, including an optical measurement from optical sensor 330, to determine whether the membrane defining volume AVS 335 is filling. If not populated, substate 391 waits a predetermined amount of time. Thereafter, substates 288, 289 and 391 may be repeated for at least a predetermined number of cycles and/or until a predetermined amount of time has passed, after which substate 390 determines that an error condition exists, for example because the reservoir 331 is empty and/or a valve is stuck, e.g. valve 332 may be stuck closed, etc. Additionally or alternatively, if the measurement taken during substate 389 is outside a predetermined range and/or is beyond a predetermined threshold, substate 390 may determine that an error condition exists.

[000614] Referring again to Figure 84, after state 363 is performed, another positive valve leak test is performed during state 364 and another negative valve leak test is performed in state 365.

[000615] State 366 takes an AVS measurement to determine the volume of the AVS chamber 355 (see Figure 95). Referring now to Figures 95 and 96: Figure 95 shows the flow-controlled membrane pump 358 of Figure 83 in use during an AVS 366 measurement state and Figure 96 shows a more detailed view of the AVS 366 measurement state of the Figure 84.

[000616] State 366 includes substates 392 and 395. Substate 392 causes speaker 329 to emit one or more acoustic frequencies and substate 393 takes measurements from microphones 327 and 328 to determine an acoustic response. The acoustic response is correlated to a volume of the AVS chamber 335 and is thus also correlated to the fluid in the AVS chamber 335. The acoustic response and other measurements are taken during substate 393. Substates 392 and 393 may optionally be repeated , for example, shown as substate 395. If one or more measurements of substate 392 are outside a predetermined range and/or are beyond a predetermined threshold, substate 394 may determine that an error state exists.

[000617] Referring again to Figure 84, after AVS measurements are taken in state 366, emptying state 367 empties the AVS volume 335. Figure 97 shows the flow-controlled membrane pump 358 of Figure 83 in use during the emptying state 367 of Figure 84 and Figure 98 shows a more detailed view of the emptying state of Figure 84.

[000618] As shown in Figure 98, emptying state 367 includes substates 396 to 399. Substate 396 establishes valves 350 and 349 and pump 353 to apply a positive pressure to reference volume 324. Substate 396 also opens valve 336 to allow fluid to flow to patient 338. During substate 387, various measurements are taken and substate 397 continues to substate 399 to wait a predetermined amount of time. Substates 396, 397, and 399 repeat until the optical sensor 329 determines that the AVS volume is below a predetermined amount. If measurements taken during substate 397 are outside a predetermined range and/or a measurement exceeds a predetermined threshold (i.e., above or below the threshold) substate 398 determines that an error condition exists. If substate 399 repeats a predetermined number of times and/or operates for a predetermined amount of time, substate 398 may determine that an error condition exists, e.g., a stuck valve such as valve 336 and/or an occlusion to downstream may be preventing the AVS volume from discharging liquid to patient 338, for example.

[000619] Referring again to Figure 84, after state 367, state 368 takes an AVS measurement. The AVS measurement 368 can be compared to the AVS measurement 366 to determine an amount of fluid delivered to a patient 338. For example, in the emptying state 367, some of the fluid may remain in the AVS volume 335. Comparing the difference between the AVS measurements, the amount of fluid discharged down the tube for patient 338 can be estimated.

[000620] Figure 99 shows a membrane pump 411 that has an elastic membrane 412 that is flush with a disposable portion 413 and applies a force to a liquid in accordance with an embodiment of the present description. That is, the action of the membrane 412 provides an actuation to move fluid through the membrane pump 411. The membrane pump 411 includes an AVS installation 417 that couples to a disposable portion 418. The AVS installation 417 can be quickly fitted, may screw onto or may include latches for attaching to the disposable portion 418. The membrane pump 411 includes a pneumatic fill port 414. The pneumatic fill port 414 may be connected to any air pump as described herein. In still further embodiments, the pneumatic fill port 414 may be connected to a liquid pump, e.g., a syringe pump or other liquid pump. In some embodiments, positive and negative pressures are applied to the pneumatic fill port 414, which is used in conjunction with valves 415 and 416 to pump fluid. In some embodiments, a negative pressure is applied to the pneumatic fill port 414 and the elastic property of the membrane 412 is used to suck liquid through the valve 416. In some embodiments, a positive pressure is applied to the pneumatic fill port 414 and the elastic property of membrane 412 is used to expel liquid through valve 415.

[000621] Figures 100 and 101 show two embodiments of lung-type pumps in accordance with the embodiments of the present description. Figure 100 shows a lung-type pump 419 and Figure 101 shows a lung-type pump 420.

[000622] The lung-type pump 419 of Figure 100 includes a rigid body 421 that has an AVS or FMS port 425 for measuring the volume of a reservoir 425 that is flexible. FMS is described in US Patent No. 4,808,161; 4,826,482; 4,976,162; 5,088,515; 5,193,990; and 5,350,357. In some embodiments, positive and/or negative pressure is applied to port 425 to facilitate the pumping action of lung-type pump 419. Reservoir 424 is in fluid communication with valves 422 and 423. Reservoir 424 may be molded or connected to the tube 431 or is formed under vacuum from the tube 431, for example, a dome. The rigid body 421 can seal completely around the tube 431 as it passes through the rigid body and connects to the reservoir 424. By applying positive or negative pressure to port 425, fluid can be drawn into and out of the tube 425. outside reservoir 424. This positive and negative pressure may be supplied by a manifold that also contains a reference chamber that allows FMS measurements through port 425. Additionally or alternatively, rigid body 421 may include hardware, such as, for example, example, a processor to control valves 422 and 425, an AVS installation coupled to port 425, etc. Liquid is drawn from valve 422 and exits through valve 423. Valves 422 and 423 may be diaphragm valves. Valves 422 and 423 may be alternately closed and opened relative to each other and synchronized with any positive and/or negative pressure applied through port 425. For example, a pumping sequence may occur as follows: (1) close valve 413 and open valve 422; (2) apply negative pressure to port 425; (3) close valve 422; (4) estimating the volume of fluid in reservoir 425 (e.g., using AVS or FMS); (5) repeat steps (1) to (4) until a predetermined volume is within the reservoir; (6) open valve 425; (7) apply positive pressure to valve 425; (8) close valve 423; (9) estimate the volume of fluid in the reservoir; (10) comparing the volumes measured during steps (9) and (4) to determine a quantity of liquid discharged; (11) and repeat (1) to (10) until a predetermined amount of liquid has been pumped.

[000623] The lung-type pump 420 of Figure 101 includes a rigid body 426 that has an AVS or FMS port 430 for measuring the volume of a reservoir 429 that is flexible. In some embodiments, positive and/or negative pressure is applied to port 430 to facilitate the pumping action of the lung-type pump 420. The reservoir 429 is in fluid communication with valves 427 and 428. The lung-type pump 420 can be similar to the lung-type pump 419 of Figure 99; however, valve 427 is opened and valve 428 is closed to pump fluid into the reservoir; and valve 428 is opened and valve 427 is closed to pump fluid out of the reservoir.

[000624] Figures 102 to 104 show various gaskets for sealing a lung-type pump in accordance with additional embodiments of the present description. Figure 102 shows a tube 432 that can be sealed by the rigid body 433 and 434 of the lung-type pump (e.g., the rigid body 421 of Figure 99 or the rigid body 426 of Figure 100). In other embodiments, 422 and 424 may be part of a housing, locking, or door mechanisms. Figure 103 shows a pipe 425 that includes a gasket seal 426. The gasket seal 426 can push left and right causing a better seal where the two sides of the sealing surfaces meet (i.e., 422 and/or 424). Figure 104 shows another way of sealing a pipe 432 including a gasket 427 that seals by being compressed between a valley structure 427 and a compression plate 429.

[000625] Figure 105 shows another lung pump 430 in accordance with another embodiment of the present description. The lung-type pump 430 includes a rigid part 431 attached around a tube 432 that creates a face seal gasket that seals against a ring structure 433 when pressure is applied to the rigid part 431. The rigid part 431 can be a circular structure, for example a ring structure similar to a washer.

[000626] Figures 106 to 112 illustrate the operation of a piston pump while performing various checks in accordance with an embodiment of the present description. The checks described in conjunction with the piston pump of Figures 106 to 112 can also be used with a peristaltic pump having a spring-driven plunger as described herein. Figure 106 shows a pump 434 that includes a piston 435, a diaphragm 436, an inlet valve 437, an outlet valve 438, and a chamber pump 439. The piston 435 may be coupled to a linear actuator 54 (not shown in Figures 106 to 112) which is coupled to a processor 37 for control (see Figure 3).

[000627] The opening of valves 437 and 438 can be timed with the movement of piston 435 to allow the integrity of the valves to be checked periodically during pump operation. Piston 435 applies a pressure or vacuum to check valves 437 and 438 to confirm that one or both are not leaking before opening the other valve. This process can be used to protect against free-flow conditions; if one valve is not sealing properly, the other valve will not open. The same setup can be used to check air in the pumping chamber, upstream occlusions, and downstream occlusions.

[000628] In some embodiments, the piston 435 and valves 437 and 438 may be driven by a set of cams driven by a single engine. Additionally, in some embodiments, the piston 435 is spring loaded so that the cam lifts the piston 435 and the spring returns the piston 435 to the down position; this specific modality may have a relatively constant delivery pressure.

[000629] In some embodiments of the present description, the position of the piston 435 and/or the position of the diaphragm 436 can be determined using a sensor. In some embodiments, the position of the piston 435 may be determined using an encoder, a magnetic sensor, a potentiometer, or rotary sensors on a cam shaft, etc. In additional embodiments, the position of the piston 435 is measured directly using an optical sensor, an LVDT (linear variable differential transformer) sensor, a hall effect sensor, or another linear sensor. The position of the diaphragm 436 can be determined using an AVS installation as described elsewhere herein (e.g., the AVS installation 417 of Figure 98 can be used to determine the position of the diaphragm 436). In some additional embodiments, no piston is used and the diaphragm is moved using pneumatic pressure as described herein.

[000630] Figures 107 to 112 illustrate various stages of the piston pump of Figure 106. Figure 107 illustrates an air check and leak check of inlet valve 437. Piston 435 applies a downward force while valves 437 and 438 are closed. If the piston 435 moves a predetermined distance and/or beyond a predetermined speed, the processor 37 may determine that excessive air exists within the pump chamber 439. If the piston 435 compresses an amount and continues to slowly move toward the bottom of pump chamber 439, the processor may determine that one of valves 437 and/or 438 is leaking. For example, if a valve 437 and/or 438 is leaking, the volume with the pump chamber 439 will continually decrease. The movement (or speed) caused by excessive air in the pump chamber 439 may be at a different speed than the movement caused by a leak; and, in some specific embodiments, the processor 37 can distinguish between excessive air in the pump chamber 439 and/or a leak in one of the valves 437 and 438. For example, the piston 435 can move downward at a first speed and if quickly approaches a very slow speed; if the slow speed continues, then it can be determined that the continued slow motion after the abrupt negative acceleration is an indication of a leak in one of the valves 437 and 438.

[000631] Figure 108 shows a stage in which a downstream occlusion check is performed. The outlet valve 438 is opened and the fluid in the pump chamber 439 is delivered to the patient. If the volume does not change, there may be an occlusion downstream. Additionally or alternatively, if the piston 435 moves slower than a threshold and/or moves slower than a previous fluid discharge by a predetermined amount, the processor 37 (see Figure 3) may determine that an occlusion to downstream occurred. Additionally or alternatively, if the piston 435 stops moving less than a predetermined amount of movement (e.g., with a predetermined force applied to the piston 435), then the processor 37 may determine that a downstream occlusion has occurred.

[000632] Figure 109 illustrates the stages in which the outlet valve 438 is closed. Figure 110 illustrates the stage at which the piston 435 is lifted. Outlet valve 438 remains closed. Stretching the diaphragm 436 results in a vacuum in the pump chamber 439. If either valve 437 and 438 is leaking, the fluid in the pump chamber 439 will increase. If the diaphragm 436 moves by a predetermined amount, the processor 37 may determine that a valve is leaking and issue an alert and/or alarm.

[000633] Figure 111 illustrates a stage in which the pump chamber 438 is filled and an upstream occlusion check is performed. The inlet valve 437 is opened and the pump chamber fills 438 with liquid. If the pump chamber fails to fill by a predetermined amount, then the processor may determine that an upstream occlusion exists or the IV bag is empty. Additionally or alternatively, if the chamber fills 438 very slowly or slower than a previous fill by a predetermined amount, the processor 37 may determine that an upstream occlusion exists. Figure 112 illustrates the stage at which the inlet valve 437 is closed. The stages illustrated in Figures 107 to 112 may be repeated until a predetermined amount of fluid is delivered to a patient.

[000634] Figures 113 and 114 illustrate a piston pump 441 in accordance with another embodiment of the present description. As shown in Figure 113, the piston pump 441 includes a disposable cassette 442 including a preformed membrane 440 and a cassette body 445. The preformed membrane 440 will be one or more of an elastomeric PVC such as Sarlink, Pebax, Kraton, a Santoprene, etc. The preformed membrane 440 may be attached to the cassette body 445 using any method, including heat bonding, laser welding, using an adhesive or solvent bond, ultrasonic clamping or welding, RF welding, or overmolding. When the preformed membrane 440 is compressed as shown in Figure 114, the membrane will return to its original shape as shown in Figure 113 after the piston 443 is withdrawn. Figures 115 and 116 show two views of a cassette 444 having several membrane pumps 441. The cassette 444 may be formed by a rigid body defining the cassette body with two elastic layers disposed around the rigid body. The rigid body can form the reservoir so that the elastic layer forms the preformed membrane as illustrated in Figures 113 and 114.

[000635] Figure 117 shows an installation 446 that has a cassette 447 that includes a membrane pump 451 and volcano-type valves 449 and 450 in accordance with an embodiment of the present description. The membrane pump 451 includes a pump plunger 452 that interfaces with a membrane 451. As the plunger 451 cycles, fluid is drawn from the fluid path 454 and out of the fluid path 456. The volcano-type valve 449 is a one-way valve that allows fluid to fluid volume 455 from the volcano-type valve 449, but not in reverse. An actuator may press against membrane 456 in some embodiments to assist the action of a volcano-type valve 449.

[000636] The volcano-type valve 450 is a one-way valve that allows fluid out of the fluid valve 455 through the fluid path 455 and the volcano-type valve 450 (but not in reverse). An actuator may press against membrane 457 in some embodiments to assist the action of a volcano-type valve 450.

[000637] Installation 446 also includes an AVS installation 448. The AVS installation includes a reference volume 458 that has a speaker 459 and a microphone 460. The variable volume 461 includes a microphone 462. The speaker 459 and the Microphones 460 and 462 are coupled to a processor 37 to measure the volume of fluid volume 455 and coordinate the operation of plunger 452 as described herein.

[000638] The plunger 452 may interface with one or more acoustic seals coupled to the AVS installation 448. The processor 37 may be in functional communication with a position sensor (e.g., one coupled to a linear plunger actuator) to determine the position of the plunger 452. The processor 37 may consider the amount of volume that the plunger 37 displaces as it switches in and out of the variable volume 461; This volume correction can be made by directly measuring the displacement of the piston (452) or by measuring an angle of the drive shaft coupled to a cam that moves the piston 452.

[000639] Figure 118 shows a roller mechanism 463 of a cassette-based pump in accordance with an embodiment of the present description. The roller mechanism 463 includes rollers 464, 465 and 466. The rollers 464, 465 and 466 move in a circular direction and apply downward pressure again to a cassette 467 having a cassette body 468 and a membrane 469. rollers 464, 465 and 466 may be on a track and may be spaced so that at least one roller engages the cassette 467. The roller mechanism 463 may be controlled by a stepper motor. The roller mechanism 463 can assist pump liquid at a rate of, for example, 0.1 ml/h.

[000640] The roller mechanism 463 can be used to estimate fluid flow based on the speed of its movement, for example. Rollers 464, 465, and 466 may be disengaged from cassette 467 to facilitate unoccluded flow and/or create a desired free-flow condition.

[000641] Figure 119 shows fluid paths 470 of a cassette-based pump for use with the roller mechanism of Figure 118 in accordance with an embodiment of the present description. The fluid paths 470 include a roller interaction area 471 that has a path 472 and a deflection path 473. The fluid paths 470 may include a vacuum formed film attached to a grooved backing to form raised flexible features. Path 470 includes occluders 474 and 475. Occluders 474 and 475 can be independently occluded. Paths 472 and 473 may have the same or different cross-sectional areas. The roller mechanism 463 may interact with the roller interaction area 472 to create different flow rates based on the rate of movement of the roller mechanism 463 and the total cross-sectional area of all channels that are unoccluded (e.g. , which of the occluded features 474 and 475 are engaged). Occluder features 474 and 475 may be volcano-type valves with a plunger that may be applied to the volcano-type valve membrane to prevent fluid from flowing in any direction. In other embodiments, occluders 474 and 475 may be diaphragm valves coupled to an actuator, such as a solenoid.

[000642] The fluid paths 470 may include a fluid capacitor 476 to store the liquid flow (e.g., smooth the liquid). Additionally or alternatively, an AVS installation can be coupled to the fluid capacitor 476 to measure the fluid flowing therebetween.

[000643] In another embodiment, one or more of the fluid paths 472 or 473 include a flat flexible film attached to a grooved support with the features molded into the rigid support (cassette body). In this embodiment, roller 463 has a feature that forms recesses in channel 478 in order to pinch channel 478. This embodiment may also have molded features that allow a ball-head piston to variably restrict flow through channel 478 (e.g., occluded features 474 and 475). The geometry of the features that form recesses in the channel and the piston head can be adjusted to allow for different flow profiles based on linear piston engagement. In one embodiment, the disposable has a channel 472 for the roller mechanism 463 and a second channel 473 that acts as a bypass of the roller area. The two channels 472 and 473 in conjunction with the occluders 474 and 475 allow the cassette (which may be disposable) to be used in a bypass mode or a pump mode. In some embodiments, the roller mechanism 463 of Figure 119 is always engaged above the channel 478, but not over the bypass channel 473.

[000644] In one embodiment, the roller mechanism 463 can be used for high flow rates and the bypass 474 can be used for low flow rates. For example, in some specific embodiments, when fluid paths 472 and 473 have a cross-sectional area of 0.4 cm, flow rates can be from 100 ml/h to 1,000 ml/h with the use of a motor. step to actuate the linear path of the rollers from 250 cm/h to 2,500 cm/h; 473 bypass is used to achieve flow rates under 100 cm/hour.

[000645] Figure 120 shows fluid paths 478 of a cassette-based pump for use with the roller mechanism of Figure 118 in accordance with an embodiment of the present description. Fluid paths 478 include two paths 479 and 480 and a bypass path 481. The roller mechanism 470 of Figure 118 interfaces with fluid paths 470 and 480. Fluid paths 478 are also coupled to occluders 482, 483 and 484.

[000646] Figure 121 shows stages 310, 311 and 312 of an infiltration test in accordance with an embodiment of the present description. The infiltration test illustrated by Figure 121 includes an occluder roller 313 that is pressed against a tube 314 (as shown in stage 311) which is then pulled through a rolling motion (shown in stage 314). The occluder roller 313 may be on pumps 19, 20 and/or 21 (See Figure 1) or on the infusion site monitor 26 (See Figure 2). The monitoring client 6 may instruct the occluder roller 313 to perform an infiltration test. For example, monitoring client 6 may instruct a stepper motor coupled to roller occluder 313 to pull liquid out of patient 5 (See Figure 1). The monitoring client 6 may then receive an estimate of the amount of blood entering the infusion site monitor 26 (see Figure 1) from the infiltration detector 32 (see Figure 2). The infiltration detector 32 determines whether the appropriate amount of blood is drawn into the infusion site monitor 26 during the infiltration test stages or, alternatively, the monitoring client 6 may receive raw data from the infiltration detector 32 to determine whether the appropriate amount of blood is drawn into the infusion site monitor 26 (See Figures 1 and 2).

[000647] As previously mentioned, the infiltration detector 32 of Figure 2 may be a camera-based infiltration detector 32 as described above in relation to the system 108 of Figure 33 when used to capture the images illustrated by Figures 37 and 38. Figures 37 and 38 illustrate images taken by camera 109 of system 108 of Figure 33 to estimate blood entering infusion site monitor 26 of Figure 2 during an infiltration test. That is, the system 108 of Figure 33 may be within the infiltration detector 32 of the infusion site monitor 26 (see Figure 2) to detect blood when the roller occluder 313 of Figure 121 acts to draw blood into the infusion site monitor 26 in Figure 2.

[000648] During stage 312, a withdrawal volume 315 is thus drawn from a patient 5. A camera 109 of Figure 33 on an infusion site monitor 26 (e.g., within the infiltration detector 32) can determine whether the blood is drawn from the patient as shown in Figures 37 and 38. If no blood is drawn into the tubing within the infusion site monitor 26 (see Figure 2), it may be an indication that an infiltration has occurred. Additionally or alternatively, the camera 109 of Figure 33, in conjunction with a pressure sensor 33 and/or volume sensor 169, can be used to determine what amount of pressure causes blood to be drawn back into the tube 41.

[000649] In some embodiments, fluid is returned to the patient 5 by actuating the rolling occluder 313 in the opposite direction or by lifting the occluder 313 from the tube 314. In an additional embodiment, a compatible upstream reservoir may be included that retains the fluid withdrawal (valves can direct fluid back to compatible upstream reservoir). The upstream reservoir may be coupled to an AVS chamber as described herein or is a separate chamber. The AVS chamber may have fluid withdrawal volume measured by a processor coupled thereto and/or communicated to the monitoring customer 6. Additionally or alternatively, pumps 19, 20 and 21 are stopped during an infiltration test or may assist in removing the fluid, in conjunction with the bearing occluder 313 or instead of the bearing occluder 313.

[000650] In additional embodiments, a compatible chamber is used between the roller occluder 313 and the patient 5. The volume of displacement of the membrane chamber during withdrawal is monitored using, for example, AVS or an optical sensor. The deflection of the membrane chamber is proportional to the pressure in the fluid tube 314, the amount of membrane deflection is proportional to the effort to draw blood into the tubing. A threshold amount of withdrawal pressure necessary to pull blood out of the patient 5 is used to determine whether an infiltration exists. Additionally, if a threshold amount of time is required for withdrawal, this can be used as an indication that a downstream occlusion exists or an infiltration exists. Therefore, the membrane chamber could be monitored over time and detect a rate in pressure change that is an indication of withdrawal effort (as determined by processor 37 of Figure 2).

[000651] Figure 122 shows the stages of an infiltration test 316 and 318 in accordance with an embodiment of the present description. A piston 319 may be disposed anywhere along the fluid tube or in a pump 19, 20 or 21 of Figure 2 or the piston 319 may be disposed in the infusion site monitor 26 of Figure 2. At stage 316, a Valve 318 remains open and piston 319 is pressed against a membrane 320, but fluid continues to flow to the patient. In stage 317, the valve 318 is closed and the piston 319 is raised, after which the resilience of the membrane 320 recoils and draws the fluid back. The withdrawal fluid returns to the patient when the piston actuates back to the resting state as shown in stage 316. A camera 109 of Figure 33 on an infusion site monitor 26 on the infiltration detector 32 (see Figure 2) can determine whether blood is taken from patient 5 as described above. If no blood is drawn into the tubing within the Infusion Site Monitor 26 (see Figure 2), this may be an indication that an infiltration has occurred.

[000652] In some embodiments, the elastomer surface area and elastomer properties are selected in combination with the chamber volume so that there is a maximum determined fluid pressure that is applied during withdrawal, e.g., the properties may be chosen so that there is sufficient withdrawal pressure to withdraw blood to the monitoring area, however, there would be insufficient pressure to withdraw blood for monitoring when an infiltration has occurred. Additionally or alternatively, blood must be withdrawn within a predetermined amount of time; otherwise, it may be determined that an infiltration condition exists. The amount of time allowed for withdrawal can be used with predetermined criteria to determine whether an infiltration has occurred (i.e., allowing the withdrawal chamber to persist with withdrawal for a predetermined amount of time while looking for the indication of blood with the use of the camera 109 and determine that an infiltration has occurred if no blood is detected by the infiltration sensor 32 (see Figures 2 and 33), e.g., camera 109, before the predetermined amount of time has passed).

[000653] Figures 123 and 124 show a cell-based reservoir 485 in accordance with an embodiment of the present description. The cell-based reservoir 485 may be reservoirs 2, 3, or 4 of Figure 1. The cell-based reservoir 485 includes cell foam 486 that can absorb liquid constructed of a compatible material to dampen the movement of a substance. of infusion. The cell foam 486 may include a membrane 487. The reservoir base 488 may be constructed using a rigid, semi-rigid, or non-rigid fluid reservoir to increase infusion substance stability in the presence of fluid shear.

[000654] For example, when using a semi-rigid base 488, the cell foam 486 may include an open-cell silicone foam to fill the normally empty reservoir cavity. The 486 cell foam can help prevent spillage of reservoir contents to help preserve the stability of the infusion substance in some embodiments. By choosing a foam with a high degree of compressibility in relation to both the pumping mechanism and the spring rate of the foldable membrane 487, the residual volume of the cell foam 486 can be minimal in some embodiments.

[000655] Figures 125 and 126 show a tube-based reservoir 489 in accordance with an embodiment of the present description. The cell-based reservoir 489 may be reservoirs 2, 3, or 4 of Figure 1. The tube-based reservoir 489 includes a tubing reservoir 490 that can house a liquid. The tube-based reservoir 489 may be vented through a filter 491. The filter 491 may be part of the vent of Figures 51 to 55. For example, a pumping mechanism (e.g., a pump as described herein, but 125 and 126) can draw fluid from the tubing reservoir 490 stored in a rigid reservoir cavity 492 (the base 492 may be flexible, rigid, semi-rigid and/or part of a cassette in some embodiments). The tubing reservoir 490 can help prevent spillage of reservoir contents thereby helping to preserve stability in some embodiments.

[000656] Figure 127 shows stages 1 to 8 that illustrate a method for operating a plunger pump 493 in conjunction with an AVS installation 494 in accordance with an embodiment of the present description. A fluid path 495 includes valves 496, 497 and 498.

[000657] Stage 1 shows valve 498 closed with valves 496 and 497 open. Valve 497 can be closed while plunger 499 is withdrawn to check whether valves 498 and 497 are leaking. For example, a constant force can be applied to the plunger 499 by pulling the plunger upward (e.g., from a spring) and both valves 496 and/or 497 can be closed. If the plunger 499 moves upward beyond a predetermined amount or faster than a predetermined speed, the processor 37 (see Figure 2) may determine that a leak has occurred. Additionally or alternatively, valve 496 may be closed and plunger 499 applies an upward force for a predetermined amount of time and then applies a downward force. The AVS 494 installation can then perform an AVS scan. If the fluid within the AVS installation (e.g., measured by volume of fluid volume) is beyond a predetermined amount, then the processor may determine that one of the valves 496 and 498 may be leaking.

[000658] Stage 2 shows fluid being drawn into plunger pump 493. Stage 3 performs an AVS scan. Between stages 3 and 4, a leak check can be performed, for example, valves 497 and 498 can remain closed while plunger 493 applies a downward force. If there is movement beyond a predetermined amount, it may be determined by the processor that one or both valves 497 and 498 are leaking. In stage 4, the volume of fluid from the plunger pump 493 is transferred to the membrane of the AVS installation 494. In stage 5, there is an AVS scan to determine the fluid in the AVS installation 494. In stage 6, the valve 497 is opened and the fluid volume is transferred from the AVS installation 494 to the plunger pump 493. Between stages 5 and 6, the valve 497 may be temporarily left closed to perform another valve leak check.

[000659] In stage 7, valve 497 is closed. In stage 8, the fluid in plunger pump 493 is discharged. Between stages 7 and 8, valve 498 may initially remain closed to determine whether one or both valves 497 and 498 are leaking.

[000660] Figure 128 shows several stages illustrating a method for operating a plunger pump in conjunction with an AVS installation in accordance with another embodiment of the present description. Between stages 1 and 2, a leak test may be performed by holding valve 500 temporarily closed while an upward force is applied to plunger 499. In stage 2, fluid is drawn into plunger pump 493. Also during During stage 2, an AVS scan can be performed by the AVS installation 494. In stage 3, the fluid is transferred to the AVS installation 494. Also during stage 2, an AVS scan can be performed by the AVS installation 494. A leak test may be performed between stages 2 and 3 (e.g., keeping valve 501 closed while applying a downward force to plunger 499). In stage 4, fluid is drawn from the AVS installation 494 to the plunger 493. Also during stage 2, an AVS scan can be performed by the AVS installation 494. Between stages 3 and 4, a leak test can be performed by holding it if valve 501 is temporarily closed while an upward force is applied to plunger 499. In stage 5, fluid is discharged from plunger 493 to the patient (i.e., beyond the AVS installation 494). A leak test can be performed between stages 4 and 5 by keeping valve 501 temporarily closed and/or to check for backflow. A leak test may also be performed during stage 5 to check for backflow.

[000661] Figure 129 shows several stages illustrating a method for using a plunger pump 503 having an AVS installation 504 in accordance with an embodiment of the present description. In stage 1, an AVS scan is performed. In stage 2, fluid is pulled into variable volume 506. In stage 2, after fluid is pulled into variable volume 453, another AVS scan is performed. In stage 3, the fluid is discharged. In stage 3, after the fluid is flushed, an AVS scan can be performed. Note that actuator 507 is within variable volume 506. Therefore, movement of actuator 507 does not affect the volume of variable volume 506.

[000662] Figure 130 shows several stages illustrating a method for using a plunger pump 508 having an AVS installation 509 in accordance with an embodiment of the present description. The actuator 507 is located outside the variable volume 509. The plunger pump 508 uses a standard IV assembly 510 so that the compliance of the tubing 510 draws the liquid in during stage 4. Stage 2 discharges the liquid. Stages 1 to 4 may be repeated.

[000663] Stage 1, an AVS sweep is performed by the AVS installation 509 and a downstream force can be applied to the plunger 512 with both diaphragm valves 513 and 514. In stage 2, the fluid volume is discharged. In stage 3, plunger 512 is retracted, after which an AVS scan can be performed to determine whether valves 513 and 514 are leaking (e.g., compliance of piping 455 may provide a negative pressure within piping 510).

[000664] Figure 131 shows several stages 1 to 5 that illustrate a method for using a plunger pump 515 having an AVS installation 516 in accordance with an embodiment of the present description. The plunger pump 515 draws fluid into and out of the variable volume 517 via a pneumatic actuator 518. During stage 1, a positive and/or negative pressure can be applied to the variable volume 518 with both valves 519 and 520 closed. During stage one, one or more AVS scans may be performed by the AVS facility 516. If the volume estimated by the AVS facility 516 changes when both valves 519 and/or 520, then the processor 37 may determine that a leak in one or more both valves 519 and/or 520 exist.

[000665] During stage 3, a positive and/or negative pressure can be applied to the variable volume 518 with both valves 519 and 520 closed. During stage one, one or more AVS scans may be performed by the AVS facility 516. If the volume estimated by the AVS facility 516 changes when both valves 519 and/or 520, then the processor 37 may determine that a leak in one or more both valves 519 and/or 520 exist.

[000666] Figure 132 shows a plunger pump 521 with an actuator 522 within the variable volume 523 for use with a standard IV set tubing 524 in accordance with an embodiment of the present description.

[000667] Figure 133 shows several views of a cam-driven linear peristaltic pump 522 having diaphragm valves 523 and 524 and a plunger 525 within a variable volume 536 in accordance with an embodiment of the present description. Cross-sectional views 527 and 528 show two different standard IV set tubing configurations 529 below plunger 525.

[000668] Figure 134 shows a plunger pump 530 for use with a standard IV set tubing 531 with an actuator 532 outside the variable volume 533 in accordance with an embodiment of the present description. Figure 135 shows various views of a cam-driven linear peristaltic pump 534 having diaphragm valves 535 and 536, a plunger 537 within a variable volume 538 with a corresponding cam mechanism 539 outside the variable volume 538 in accordance with an embodiment of the this description. As the cam followers 540, 541 and 542 move in and out of the variable volume 535, the processor 37 of Figure 2 can adjust the measured volume to account for changes in the volume the cam followers 540, 541 and 542 affect. the variable volume. Cross-sectional views 543 and 544 show two different configurations of standard IV set tubing 545 for plunger 537 to interface.

[000669] Figure 136 shows a plunger pump 546 having a plunger 547 within a variable volume 548 with an actuator 549 outside the variable volume 548 in accordance with an embodiment of the present description. The processor 37 is coupled to a position sensor of Figure 2 to consider the volume of the plunger shaft 547 as it moves in and out of the variable volume 548.

[000670] Figure 137 shows a cam-driven linear peristaltic pump 550 having a plunger 551 within a variable volume 552 with a corresponding cam mechanism 553 outside the variable volume 552 and diaphragm valves 554 and 555 in the variable volume housing. 552 in accordance with an embodiment of the present description. Diaphragm valves 554 and 555 may also form the acoustic seal for the interface of the variable volume 552 and the standard IV set tubing 556. Cross-sectional views 557 and 558 are shown to illustrate the interface configuration of the plunger 551 with the standard 556 IV set tubing.

[000671] Figure 138 shows a plunger pump 559 having a plunger 560 within a variable volume 561 and diaphragm valves 562 and 563 outside the variable volume 561 in accordance with an embodiment of the present description. The actuator 564 (e.g., a cam mechanism, linear motor, linear actuator, etc.) is located outside the variable volume 561. The processor 37 of Figure 2 can compensate the piston shaft 560 as it moves in and out of the volume. variable 561.

[000672] Figure 139 shows various views of a cam-driven linear peristaltic pump 562 having a plunger 563 within a variable volume 564 with a corresponding cam mechanism 565 and diaphragm valves 566 and 567 outside the variable volume 564 accordingly. with an embodiment of the present description. Views 569 and 570 show two different configurations of standard IV pool tubing 568. Standard IV pool tubing 568 may be positioned by a track (e.g., defined below, above, and/or around tubing 568).

[000673] Figure 140 illustrates stages 1 to 5 of occlusion detection using a plunger pump 571 having an AVS installation 572 and a spring-driven diaphragm mechanism 573 within the variable volume 574 in accordance with an embodiment of this description. The 571 plunger pump includes the 575, 576, and 577 diaphragm valves.

[000674] In stage 1, diaphragm valves 575, 576 and 577 are closed. The variable volume 574 can be measured as the spring-driven diaphragm mechanism 573 compresses the tube 578. If the volume of the variable volume increases (e.g., the tube diameter within the variable volume 574 decreases), then the variable volume processor 37 Figure 2 may determine that one or both valves 576 and 577 are leaking. Additionally or alternatively, the spring-driven diaphragm mechanism 573 may include a sensor for estimating the volume of liquid within the tube 573 within the variable volume 574. The sensor may be, for example, a linear hall effect sensor. If the sensor indicates that the clamping mechanism 573 is closing slowly even though the diaphragm valves 575, 576, and 577 are closed, the processor 37 may determine that an error condition exists (see Figure 2).

[000675] In stage 2, valve 576 is open and actuator 579 compresses tube 573 thus filling the tube within the variable volume with a liquid. In stage 3, valve 576 is closed. In stage 4, valve 577 is open. If there is no occlusion, the liquid inside the spring-driven diaphragm mechanism 573 will discharge the liquid. In Figure 137, stage 4 shows a view 580 in which there is no occlusion and the spring-driven diaphragm mechanism 573 discharges liquid, and stage 4 also shows a view 581 in which the spring-driven diaphragm mechanism 573 does not discharge ( or does not completely discharge) the liquid. In some embodiments of the present disclosure, the position of then spring-driven diaphragm mechanism 573 during stage 4 is used to determine whether a downstream occlusion condition exists (e.g., processor 37 may determine that an occlusion exists). . Stage 5 shows two views 582 and 583. Stage 5 view 582 shows when no downstream occlusion exists and view 583 shows stage 5 when a downstream occlusion exists (note the difference volumes of the spring-driven diaphragm mechanism 573 in both views 582 and 583). An AVS scan and/or the position sensor of the spring-driven diaphragm mechanism 573 may be used in stage 5 to determine whether the volume of liquid within the variable volume 573 exceeds a predetermined threshold such that the processor 37 of Figure 2 determines that downstream occlusion exists.

[000676] Figure 141 shows a pump 600 with a spring-loaded plunger 604 within a variable volume 605 of an AVS installation 606 with an actuated plunger 604 outside the variable volume 605 in accordance with an embodiment of the present description. Valve 602 may be closed and valve 601 opened with plunger 604 retracted to allow tube 607 to push fluid beneath plunger 604.

[000677] Valves 601 and 603 are closed and valve 602 is open while the plunger 604 presses against the tube 607 to force fluid into the tube region 607 disposed within the variable volume 605; this causes the spring-loaded (or spring-driven) plunger 604 to act to increase the amount of energy stored in its spring. Valve 602 is closed and an AVS measurement is taken. Therefore, the diaphragm valve 603 is opened which forces the fluid within the variable volume 605 out of the tube 607 and toward the patient. Therefore, valve 602 is closed and another AVS scan is performed. The AVS volume measurements are compared to determine the amount of fluid discharged through the pump 600. The spring-driven plunger 604 may be a single plunger with a spring attached to a shaft to apply a downward force to the tube 607.

[000678] Figure 142 shows a linear peristaltic pump 608 with diaphragm valves 609 and 610 and a cam shaft 611 disposed within a variable volume 612 of an AVS installation 613 having the spring-driven diaphragm mechanism 614 (see view 615) disposed therein and a plunger 616 and a diaphragm valve 617 outside the variable volume 612 in accordance with an embodiment of the present description. The manner of operation may be the same as the pump 600 of Figure 141 (e.g., the plunger 616 forces fluid to expand the clamping mechanism 614 and load the associated springs).

[000679] Figure 143 shows a linear peristaltic pump 618 with diaphragm valves 619, 620 and 621 and a plunger 622 disposed outside a variable volume 623 of an AVS installation 624 in accordance with an embodiment of the present description. The manner of operation may be the same as in pump 600 of Figure 141.

[000680] Figure 144 shows stages 1 to 5 of a plunger pump 625 having a camera or optical sensor 626 for measuring the volume within a tube 627 residing within a chamber 628 in accordance with an embodiment of the present description . The plunger pump 625 includes a spring-driven diaphragm mechanism 629. An actuator 634 applies a pumping force to force fluid into the tube region 627 within the chamber 628 in a manner similar to the pump 600 of Figure 141.

[000681] In stage 1, valves 630, 631 and 632 are closed. The optical sensor or camera 626 estimates the volume within the region of the tube 627 disposed within the chamber 628. The plunger 633 may compress the tube 627 to determine whether the plunger 633 moves beyond a predetermined amount to perform a check of the valves 630 and 631. That is, if the plunger 633 is moved beyond a threshold amount, a processor 37 may determine that one of the valves 630 and 631 is leaking.

[000682] In stage 2, valve 631 is opened and fluid is forced into chamber 628 by actuation of plunger 633. In stage 3, another optical volume estimate is made after both valves 631 and 632 are closed. In stage 4, valve 632 is open. If an occlusion exists, the spring-driven clamping mechanism 629 cannot discharge all of the fluid out of the tube 627 into the chamber 628. If no occlusion exists, then the spring-driven diaphragm mechanism 629 can discharge the fluid. During stage 5, a volume measurement is made to determine if fluid has discharged beyond a threshold. If fluid has not been discharged beyond a threshold, processor 37 of Figure 3 determines that an occlusion exists.

[000683] Figure 145 shows a plunger pump 635 that has a chamber 636 that has an optical sensor 637 for estimating the fluid volume of a tube 638 that has a spring-driven diaphragm mechanism 639 surrounding the tube 638 and a plunger 640 and diaphragm valves 641, 642 and 643 in accordance with an embodiment of the present description. The optical sensor 637 may be an LED time-of-flight device or a camera. The manner of operation of the plunger pump 635 may be the same as the plunger pump 625 of Figure 144.

[000684] Figure 146 shows a plunger pump 644 having a chamber 645 having an optical sensor 646 for estimating fluid volume from a tube 647 having a spring-driven diaphragm mechanism 648 surrounding the tube 647 and a plunger 649 and diaphragm valves 650, 651 and 652 outside the chamber 645 in accordance with an embodiment of the present description. The plunger pump 644 may operate in the same manner as the plunger pump 625 of Figure 144.

[000685] Figure 147 shows several views of a plunger pump 653 having an AVS installation 655 with a diaphragm valve 656 and 657 disposed within the variable volume 658 of the AVS installation 659 and a plunger 660 and a diaphragm valve 661 arranged outside variable volume 658 in accordance with an embodiment of the present description. Note that diaphragm valves 656 and 657 completely traverse the variable volume 658. Figure 148 shows two cross-sectional views of the plunger pump of Figure 147 in accordance with an embodiment of the present description. Figure 149 shows two alternative cross-sectional views of the plunger pump of Figure 147 in accordance with an embodiment of the present disclosure. Note in the two views of Figure 148, the diaphragm valve is arranged around the tube and in Figure 149, the diaphragm valve is arranged on one side of the tube.

[000686] Figure 150 illustrates stages 1 to 4 during normal operation of a plunger pump 662 having a spring-driven plunger 663 in accordance with an embodiment of the present description. In stage 1, the plunger 663 is pulled back from the tube 664 and the diaphragm valve 665 is opened. An AVS measurement is taken. In stage 2, diaphragm valve 665 is closed and plunger 663 compresses tube 664. Another AVS measurement is taken. In stage 3, diaphragm valve 666 is opened and plunger 663 pushes fluid out of tube 664. An AVS scan is performed to estimate the volume of fluid delivered. In some embodiments, the plunger 663 includes a linear hall effect sensor that correlates the movement of the plunger between stages 2 and 3 to estimate the amount of fluid discharged.

[000687] Figure 151 illustrates the stages for detecting an occlusion for the plunger pump 622 of Figure 150 in accordance with an embodiment of the present description. Stage 3 compares AVS measurements when an occlusion occurs versus normal fluid delivery. The processor 37 of Figure 3 can detect when not enough liquid is delivered thereby indicating to the processor that an occlusion has occurred.

[000688] Figure 152 illustrates stages 1 to 2 for leak detection for the plunger pump 622 of Figure 150 in accordance with an embodiment of the present description. In stage 1, diaphragm valve 665 is opened and plunger 663 is opened thereby drawing fluid into tube 664. In stage 2, after diaphragm valve 665 is compressed against tube 664, the plunger applies a force against the tube 664. If either valve 665 and 666 were leaking, in stage 2, the AVS measurement would indicate a fluid leak (i.e., the variable volume would increase).

[000689] Figure 153 illustrates stages 1 to 2 for detecting a bubble and/or failed valve detection for the plunger pump 602 in accordance with an embodiment of the present description. As shown in stage 2, if the variable volume increases beyond a predetermined threshold and does not continue to increase, processor 37 of Figure 3 may determine that the bubble exists in tube 664.

[000690] Figure 154 illustrates the stages for empty reservoir detection and/or upstream occlusion detection for a plunger pump 662 in accordance with an embodiment of the present description. As shown in stage 2, if the AVS scans indicate that fluid is not being drawn into the tube 664, then the processor 37 of Figure 3 may determine that the upstream reservoir is empty.

[000691] Figure 155 illustrates the stage for preventing free flow for a plunger pump 662 in accordance with an embodiment of the present description. That is, when a free flow condition is detected, the plunger 663 may compress against the tube 664 to stop the free flow.

[000692] Figure 156 illustrates the stages for a negative pressure valve check for plunger pump 662 in accordance with an embodiment of the present description. Stage 1, plunger 663 is compressed against tube 664 and both valves 665 and 665 are closed. In stage 2, plunger 663 is lifted from tube 665. If there is a leak, compliance of tube 664 will pull in fluid that is detected by AVS scans. As shown in Stage 3, valves 665 and 665 are opened.

[000693] Figures 157 to 158 show views of a plunger pump 670 having a cam shaft 671 passing through the variable volume 672 of an AVS installation 673 in accordance with an embodiment of the present description;

[000694] Figures 159 to 162 illustrate various cam profiles in accordance with various embodiments of the present description. The cam profiles of Figures 159 to 162 can be used with the peristaltic pump 662 of Figures 150 to 158 or any sufficient pump disclosed herein.

[000695] Figure 159 shows a cam profile that uses the integrity check described in Figures 150 to 158 except for a negative pressure valve check and can be used for forward pumping and reverse pumping. Backward pumping may be used during an infiltration test as described herein. Figure 160 shows a cam profile that uses the integrity checks described in Figures 150 to 158 without the negative pressure check. Rotating the cam in a back and forth manner causes fluid flow in the cam profile of Figure 160 when the cam is rocked from 0 to 155 degrees. Further pumping is performed on the cam profile of Figure 160 by rotating the cam shaft back and forth from 315 degrees to 160 degrees. In Figure 161, a cam profile is shown that uses the integrity check described in Figures 150 through 158 except for a negative pressure valve check. The cam profile in Figure 161 can be used to provide fluid flow to the front of the pump. Figure 161 shows a cam profile that pulsates fluid when rotated continuously in one direction with zero total fluid flow. The graph in the lower right corner of Figure 162 shows the movement to achieve the back and forth movement of rinse fluid.

[000696] Figure 163 illustrates a peristaltic pump 675 having a plunger 676 and a diaphragm valve 677 outside a variable volume AVS 678 with two diaphragm valves 679 and 680 in the interface of the variable volume AVS 678 in accordance with a embodiment of the present description. Figure 164 illustrates stages 1 to 5 of operation of the peristaltic pump of Figure 163 (in simplified version) according to an embodiment of the present description.

[000697] Figure 165 illustrates a peristaltic pump 681 that has two pistons 682 and 683 external to a variable volume of AVS 684 according to an embodiment of the present description. Figure 166 illustrates various stages 1 to 6 of the peristaltic pump 681 of Figure 165 in accordance with an embodiment of the present description;

[000698] Figure 167 illustrates a peristaltic pump 685 that has a plunger 686 with a linear sensor 687 in accordance with an embodiment of the present description. Figure 168 illustrates a graph of data from the linear sensor 687 of the peristaltic pump 685 of Figure 167 in accordance with an embodiment of the present description. As shown in Figure 168, the amount of movement of the plunger 686 between the pressurized stage (e.g., both closed diaphragm valves 688 and 689 and the plunger spring 686 applying a force again to the tube 690) and the delivery stage ( e.g., outlet diaphragm valve 689 is opened) is correlated to the amount of fluid discharged. The correlation between the amounts of fluid discharged with the delta output from sensor 687 can be determined empirically. The plunger 686 may be spring loaded against the tube 690 so that the cam only contacts a cam follower coupled to the plunger 686 in order to lift the plunger 686 in the direction of retreat from the tube 690.

[000699] Figure 169 illustrates the stages of the peristaltic pump of Figure 167 according to an embodiment of the present description. Figure 170 illustrates the detection of an occlusion condition relative to a non-occluded condition in accordance with an embodiment of the present disclosure. That is, plunger position data is shown for normal versus occluded conditions. Note that when there is an occlusion, fluid is not discharged and therefore the plunger position does not move as much. This can be detected by processor 37 of Figure 3. Figure 171 illustrates the detection of a valve leak in relation to a complete valve seal condition. Figure 172 illustrates the detection of too much air in the pipe or a valve failure for proper operation.

[000700] Figure 173 shows a block diagram illustrating the electronics of a peristaltic pump according to another embodiment of the present description. That is, Figure 173 shows the electronics of one of the pumps 16, 17 and 18 of Figure 1 in a specific embodiment. Figure 174 shows a block diagram illustrating the electronics of another embodiment of the peristaltic pump of one of the pumps 16, 17 and 18 in Figure 1.

[000701] Figure 175 shows a perspective view of the peristaltic pump 700 in accordance with an embodiment of the present description. The peristaltic pump includes an AVS chamber (see AVS chamber 714 in Figure 184). Peristaltic pump 700 includes cams 701, 702, and 703 that rotate together with a cam shaft 704 coupled to a motor via a gear 705. Cam 702 controls an inlet diaphragm valve, cam 702 controls a plunger and cam 703 controls an outlet diaphragm valve.

[000702] Cams 701 to 703 may be shaped to provide a peristaltic pumping action along the tube 707. Cams 701 to 703 may be shaped to provide a three-stage pumping action or a four-stage pumping action.

[000703] The three-stage pumping action includes stages 1, 2, and 3. In stage 1, the outlet valve is closed, the inlet valve is open, and the plunger is lifted from the tube. In one embodiment, the outlet valve is substantially closed before the inlet valve is substantially opened. In stage 2, the inlet valve is closed, and the spring-driven plunger is permitted by the cam to apply a compressive force against tube 707. In stage 3, the outlet valve is open so that the compressive force of the Spring plunger compresses the fluid toward the patient. A linear sensor (e.g. optical or Hall effect) measures the position of the piston. A processor coupled to a motor to control the camshaft 704 and coupled to the linear sensor can compare the difference in the position of the plunger at stage 2 when the plunger stops moving and compresses completely against the tube 707 and at the end of stage 3 (all fluid has been forced toward the patient and the plunger stops movement due to the fact that no additional fluid can be compressed out of the tube). In another embodiment, the processor, coupled to the processor coupled to a motor for controlling the cam shaft 704 and coupled to the linear sensor, can compare the difference in the position of the plunger in stage 2 when the rate of plunger movement falls below a threshold. set and during stage 3 when the rate of plunger movement falls below a given threshold or the plunger position falls below a set value. The limits for the rate of movement and position of the plunger are determined by calibration experiments. The processor uses the measured differences between the displacements between these two positions to correlate the difference to a volume of fluid pumped (for example, by comparing the delta value (the difference between the two measurements) to values in a lookup table). Optionally, in stage 3, the opening of the outlet valve is controlled by rotation of the cam 704 to achieve a target fluid discharge rate profile, for example, the delta is used between the stage 2 measurement and in real time as per the output valve is open in stage 3 (e.g. the delta is continuously calculated).

[000704] During stage 2, if the plunger moves beyond a predetermined limit and/or beyond a predetermined slope, one of the inlet valve and the outlet valve may be leaking. For example, if the plunger moves quickly to compress the pipe and continues to move (e.g., beyond a predetermined slope), the processor may determine that one of the inlet and outlet valves is leaking. The processor (processor 37 in Figure 3) coupled to the linear sensor can issue an alarm and/or alert.

[000705] During stage 2, whether the plunger moves beyond a predetermined limit when the cams allow spring compression to compress the tube or the movement slows as the plunger reaches the tube and then moves further beyond a predetermined limit (as the bubble is compressed), this may indicate that a bubble exists inside the tube. For example, if the plunger moves as the cam follower moves the spring-driven plunger toward the tube, then stops momentarily and then moves again, the processor can determine that the air inside the tube has been compressed. In some embodiments, movement beyond a predetermined limit may suggest that air exists within the tube. The processor coupled to the linear sensor can issue an alarm and/or alert. In some embodiments, to distinguish between a leaking valve and a bubble, a downstream bubble sensor (not shown) may be used by the processor to distinguish between two error conditions.

[000706] In some embodiments, if the spring-driven plunger in stage 2 moves toward the tube and does not engage the tube until a predetermined threshold has been crossed, the processor may determine that an upstream occlusion exists and the tube does not filled with fluid during stage 1.

[000707] In some embodiments, if the spring-driven plunger in stage 3 does not move beyond a predetermined limit, the processor may determine that a downstream occlusion exists (e.g., the tube cannot discharge fluid downstream). Additionally or alternatively, the processor may determine that a downstream occlusion exists when each cycle of stages 1 through 3, less and less fluid is discharged to a patient (i.e., compatibility is increasing by receiving downstream fluid).

[000708] In some embodiments of the present description, cams 701, 702, and 703 can be shaped to have a four-stage pumping action.

[000709] In stage 1, the outlet valve is closed, the inlet valve is open, and the plunger is lifted from the tube. In stage 2, the inlet valve is closed, and the spring-driven plunger is permitted by the cam to apply a compressive force against tube 707. In stage 3, the plunger is lifted from the tube and the outlet valve is open. In stage 4, cam 702 allows the plunger to apply the compression force of the spring plunger to compress the fluid toward the patient. A linear sensor (e.g. optical or Hall effect) measures the position of the piston. A processor coupled to a motor to control the camshaft 704 and coupled to the linear sensor can compare the difference in the position of the plunger at stage 2 when the plunger stops moving and compresses completely against the tube 707 and at the end of stage 4 (all fluid has been forced toward the patient and the plunger stops movement due to the fact that no additional fluid can be compressed out of the tube). The processor uses the measured differences between the displacements between these two positions to correlate the difference to a volume of fluid pumped (for example, by comparing the delta value (the difference between the two measurements) to values in a lookup table). Optionally, in stage 4, the movement of the plunger to compress the tube using the compression force of the plunger (as permitted by cam 702) is controlled by rotation of cam 704 to achieve a target fluid discharge rate profile, e.g. For example, the delta is used between the stage 2 measurement when the plunger completely compresses the tube and the real-time plunger movement as the plunger is allowed to compress the tube 707 (e.g., the delta is continuously calculated).

[000710] In some embodiments, a downstream occluder can be adjusted to smooth the flow of fluid to the patient.

[000711] In some embodiments, AVS can be used instead of the linear position sensor. In some embodiments, only the linear position sensor is used. In still additional embodiments, both the AVS and the linear position sensor are used.

[000712] Figures 176 to 180 show data from several AVS scans in accordance with an embodiment of the present description. The AVS scans of Figures 176 to 180 are for the peristaltic pump 700 of Figure 175.

[000713] Figure 176 shows data, including a phase and magnitude response, of a variable volume around the tube 707 of the peristaltic pump 700 of Figure 175 relative to a reference volume. That is, the data as shown in Figure 176 is correlated to the volume of air surrounding the tube 707 (see Figures 175) in an acoustically sealed region as shown in Figure 184 (i.e., a variable volume chamber).

[000714] Figure 177 illustrates several AVS sweeps performed using the peristaltic pump 700 of Figure 175. Note that although the plunger is spring loaded against the tube 707 in Sweep 3 and the outlet valve is opened by the cam 703 , fluid is not discharged downstream toward the patient. Processor 37 of Figure 3 may determine that a downstream occlusion exists in this circumstance.

[000715] Figure 178 shows several AVS sweeps that utilize pump 700 of Figure 175. In sweeps 2 and 3 of Figures 178, cam 702 allows the plunger spring to compress against tube 707, but cams 701 and 703 force the diaphragm valves to close. In sweep 3, the inlet and outlet valves remained closed; however, the variable volume is increasing, which indicates that fluid is being discharged out of one of the inlet and outlet valves. Processor 37 of Figure 3 may determine that one of the input and output valves is leaking when scan data appears in sweeps 2 and 3 despite the input and output valves remaining closed.

[000716] Figure 179 shows several AVS sweeps utilizing pump 700 of Figure 175. In sweep 1, cams 701 and 703 close the valves, and cam 702 allows the plunger spring to compress against tube 707. In sweep 2, cams 701 and 703 kept the valves closed; however, the plunger spring moved the plunger beyond a predetermined amount. The processor 37 can determine that the movement of the plunger is due to the fact that air is inside the tube under the plunger. A downstream air detector 24 (see Figure 1) can be used to distinguish between movements caused by air compressibility when air is within the tube 707 below the plunger versus a leaking inlet or outlet diaphragm valve.

[000717] Figure 180 illustrates the AVS scan performed during multiple (complete cycles) of fluid discharge towards the patient using the pump 700 of Figure 175 when there is a downstream occlusion. That is, each scan can be performed after the plunger is expected to discharge fluid toward the patient. As shown in scan 4, pump 700 is not discharging fluid. For example, the pump 700 may slowly fill the downstream compatibility of the tube 707 until the tube can no longer expand, in which case the pump 700 has difficulty pumping additional liquid downstream due to the fact that the plunger spring does not can apply enough force to pump additional liquid downstream. Processor 37 (see Figure 3) may determine that decreased liquid delivery during each cycle of pump 700 indicates that a downstream occlusion exists.

[000718] Figures 181 to 183 show various side views of a cam mechanism of the peristaltic pump of Figure 175 in accordance with an embodiment of the present description. Figure 181 shows a side sectional view of the plunger 706. The movement of the plunger 706 and the cam follower 709 is monitored by an optical cam follower position sensor 711.

[000719] There are various devices that can be used to detect the position of the pump plunger 706 and the pump diaphragm valves of Figure 175. These include, but are not limited to, one or more of the following: ultrasonic, optical (reflective, laser interferometer, camera, etc.), linear caliper, magnetic, mechanical contact switching, infrared light measurement, etc. In one embodiment, a small reflective optical sensor installation (hereinafter "optical sensor") that fits into exemplary embodiments of the peristaltic pump 175, as shown and described, for example, herein, may be used. The optical sensor in the various embodiments has a detection range that accommodates the components which the optical sensor may be detecting, for example, in some embodiments, the plunger 706. In the exemplary embodiment any optical sensor may be used, including, but not limited to, , a Sharp GP2S60, manufactured by Sharp Electronics Corporation, which is a US subsidiary of Sharp Corporation of Osaka, Japan.

[000720] In various embodiments, the pumping apparatus may be based on the principle of indirect compression of a flexible pipe segment through the application of a restoring force against the pipe segment by a spring-based apparatus. As shown in Figure 181, a cam element or lobe 702 may be eccentrically disposed on an axis 705 to cause the cam follower 709 to move in a reciprocal manner as the cam element 702 rotates. The plunger spring 710 in this illustration is oriented to drive a plunger 706 to compress the flexible tube segment 707 located within the peristaltic pump 700. Thus, in this arrangement, a spring constant can be selected for spring 710 to cause the plunger compresses the flexible tube segment 707 to the point necessary to deform the wall of the tube segment when liquid with a preselected range of viscosities is present within it, and to a predetermined flow resistance from the column of fluid to the end of a catheter or cannula fixed to the terminal end of the flexible tube. In this way, the distance and speed with which plunger 706 moves to compress tube segment 707 can provide information about the status of the tubing distal to tube segment 707, such as whether it is a complete or partial occlusion involving the tube or a fixed catheter, or if the catheter has been dislodged from a blood vessel or body cavity and into an extravascular tissue space. The movement of the spring or attached elements (such as the plunger) may be monitored by one or more sensors, where data is transmitted to a controller (e.g., processor 37 of Figure 3) for analysis of the rate and pattern of movement as the pipe segment is compressed. Examples of sensors suitable for this purpose may include, for example, Hall Effect sensors, potentiometers, or optical sensors that include LED, laser, or camera-based detection systems that have the ability to transmit data to a controller employing various forms of pattern recognition software.

[000721] The action of the peristaltic pump 700 of Figure 175 is illustrated in Figure 182. Figure 182a shows the cam element or lobe 704 in contact with the cam follower 709, compressing the spring 710 and moving the plunger 706 in the direction of of the tube segment 707. Figure 182b shows the cam lobe 704 rotated about the cam shaft 705 in the direction of retreat of the cam follower 709, allowing the spring 710 to extend and the plunger 706 to begin compressing the tube segment 707. In Figure 182c, cam lobe 704 has rotated sufficiently to completely release cam follower 709 to allow spring 710 to extend sufficiently to allow plunger 706 to completely compress tube segment 707. Assuming a an inlet valve acting on the pipe segment 707 entering the pump 700 is closed and an outlet valve acting on the pipe segment 707 releasing the pump 700 is open a volume of liquid in the pipe segment 707 will be driven distally out of pipe segment 707. Although the side view shown in Figure 182 is of a plunger, the operation of the inlet and outlet valve may be similar and/or the same.

[000722] Figure 183 illustrates a situation in which the resistance to flow of the liquid column within the pipe segment 707 is increased beyond the predetermined functional range of the spring selected for the pump 700. As the cam lobe 704 moves from from a spring compression position in Figure 183a to a spring decompression position in Figure 183b, the spring force is insufficient to compress the tube segment 707 rapidly and may only be able to compress the tube segment 707 partially, as shown. shown in Figure 183c. The rate of movement and final position of a component of the piston spring-cam follower installation may be detected by one or more sensors appropriate for that task (e.g. camera-based sensor), which may, for example, be mounted near or adjacent to plunger 706. This information can be transmitted to a controller, which can be programmed to interpret the signal pattern in light of stored data that has previously been determined empirically. The pattern of change in volume versus time of a compressed pipe segment such as that shown in Figure 180 may, in some cases, mirror the pattern to be expected of movement versus time when the relative position of a component of the plunger-follower installation cam is tracked.

[000723] Figure 184 shows a sectional view of the diaphragm valves 715 and 716 and the plunger 718 of the peristaltic pump of Figure 175 in accordance with an embodiment of the present description. In various embodiments, the pipe segment within the pumping apparatus is retained against an anvil plate during compression by a plunger. The pipe segment can be held in position by being clamped in a follower raceway so that there is sufficient space to allow lateral displacement of the pipe segment walls as it is being compressed. However, this may allow some lateral movement of the pipe segment in an uncompressed state. Figure 185 shows an alternative arrangement in which the tube segment can be held in position by fingers or flexible side arms that can separately and elastically expand to accommodate the expanding sides of the tube segment as it is compressed. Figure 185 shows a plunger comprising flexible side fingers or arms for holding a pipe segment to keep it relatively immobilized in both an uncompressed state and a compressed state. In an uncompressed or "unclamped" state, the flexible fingers fit snugly against the sides of the pipe segment, preventing lateral movement of the pipe within the pumping apparatus. In a compressed or "pinched" state, the flexible fingers expand separately and elastically to accommodate lateral displacement of the pipe segment walls as it is compressed, maintaining the general position of the pipe segment within the pumping apparatus.

[000724] Figure 186 shows an embodiment of a cam mechanism of a peristaltic pump 719 in accordance with an embodiment of the present description. A cam 720 controls a diaphragm valve 721. A cam 722 controls pistons 723, 724 and 725. A cam 726 controls another diaphragm valve 727. A latch mechanism (e.g., a magnetic latch) may prevent pistons 723 and 725 from moving to compress tube 728 as shown in Figure 187.

[000725] Figures 188, 189 and 190A show various views of a peristaltic pump 729 in accordance with the present description. Peristaltic pump 729 includes a cam shaft 730 coupled to cams 731, 732, 733, and 734 that engage cam followers 735, 736, 737, and 738, respectively. Cam follower 735 is coupled to a first diaphragm valve 739, cam followers 736 and 737 are coupled to a plunger 740, and cam follower 738 is coupled to another diaphragm valve 741. As shown in Figures 190B to 190C , plunger 740 includes a clamp 744 that engages fingers 743, forming a raceway.

[000726] Figures 191 to 195 show various views of a peristaltic pump 745 in accordance with a further embodiment of the present description. The peristaltic pump 745 of Figures 190 to 195 is similar to the peristaltic pump 729 of Figures 188 to 190C, with the exception that the peristaltic pump 745 of Figures 190 to 195 includes a torque balancing cam 746 coupled to a cam follower 747 which operates together to smooth out the rotational torque of the 748 camshaft.

[000727] Figure 196A illustrates the torque profile of a rotational cam shaft of the peristaltic pump of Figures 188 to 190C and Figures 191 to 195 according to an embodiment of the present description. Torque profile 749 shows the peristaltic pump torque of Figures 188 to 190C. Torque 750 shows the torque produced by the torque balancing cam 746 of the peristaltic pump of Figures 191 to 195. Torque profile 751 shows the net torque on cam shaft 748 caused by the smoothing operation of the torque balancing cam 746 (see also Figure 196B).

[000728] Figure 197 illustrates a cam profile for several cams for a peristaltic pump in accordance with an embodiment of the present description. The cam profile describes the four-stage pumping action described above. Solid lines describe the linear position of the cams. The dotted lines indicate the position of the piston and valves. The pump cam and piston position during the stroke are marked at 1300. The inlet valve cam and inlet valve position are marked at 1302. The output valve cam and outlet valve position are marked at 1304. In stage 1, the outlet valve closes at 1306. The inlet valve opens at 1308. The plunger is lifted from the tube at 1310, which allows fluid to enter the tube under the plunger. In stage 2, the inlet valve closes at 1312, while the plunger remains lifted from the tube. In stage 3, the plunger is allowed to compress the tube. The 1314 plunger position separates from the cam position due to the presence of fluid in the tube. The controller can perform numerous diagnostic tests including, but not limited to, leak tests, air in line, occlusions based on measured position and plunger movement during stage 3. In stage 4, the outlet valve is open at 1316 first. After the outlet valve is opened, the plunger is allowed to compress the tube, forcing liquid out of the pump. Plunger force is supplied by springs acting on the plunger or springs acting on the plunger cam followers. The cam may be formed to limit plunger descent during stage 4. The actual position of the plunger may be further limited by fluid flow out of the tube. The processor in the pump can actively control plunger position by controlling cam rotation based on the measured location of the plunger. This closed-loop motor control can provide flow rates (Figure 198). In other embodiments at higher flows, the cam and/or motor will be controlled in an open loop.

[000729] Figure 198 shows various feedback modes of a peristaltic pump according to an embodiment of the present description. In a closed loop mode, feedback from AVS and/or linear sensor measurements is used to control camshaft speed. In open loop mode, the rotational speed is selected with reference to a look-up table in response to a target fluid flow rate.

[000730] Figure 199 shows a graph illustrating data from a linear sensor used to estimate fluid flow in accordance with an embodiment of the present description; The delta value of the 752 plateau caused by the fact that both the inlet and outlet valves are closed in a peristaltic pump with the plunger compressing completely against a fluid-filled tube and the 753 plateau after the outlet valve is opened and all the fluid be expelled from the peristaltic pump and the plunger is compressing completely against the tube through the force of its spring.

[000731] Figures 200 to 206 show an alternative embodiment of a peristaltic pump 1200 in which a motor 1204 can drive a cam shaft 1206 through a gear assembly 1208. The cams can drive one or more valves 1226, 1228 and a plunger 1222 by means of levers that rotate around a common geometric axis. The tube 1202 is held in place by a port 1212. The peristaltic pump 1200 may include a receptacle for a slide occluder 1200 and mechanisms that prevent a free-flow condition in the tube during installation of the tube into the peristaltic pump 1200.

[000732] Cam shaft 1206 may include a plurality of cams 1232A to E. Cams 1232A to E may control the position of various items which may include, but are not limited to, the following: inlet diaphragm valve 1224, plunger 1222, valve 1226 output diaphragm and a torque balancer. Cams 1232A to E may contact wheels 1214A to E on cam followers 1216A to E. Cam followers 1214A to E may include magnets 1218A to E. The position of each magnet may be detected by a sensor array 1220 The pump controller may calculate the position of a pump plunger 1222 and valves 1226, 1228 from sensor signals generated by magnets 1218A to E. The peristaltic pump 1200 may include an ultrasonic sensor 1228 to detect the presence of air bubbles. air in the fluid leaving the pump. The 1228 ultrasonic sensor can communicate with the pump controller.

[000733] Cam followers 1214A to E may be L-shaped and may pivot around a central geometric axis at 1230. The cam followers are retained against the cams 1232A to E by springs 1234A to E. Spring 1234C can provide a torque balancing load. Springs 1234B and 1234D can provide the force to drive the plunger toward the anvil plate 1236. Springs 1234A and 1234E can provide the force to close the diaphragm valves 1226, 1228 against the anvil plate 1236.

[000734] Figure 207 illustrates the installation of the tube with the slide occluder in the peristaltic pump 1200. In step 1, the port 1212 is open. In step 2, the tube 1202 and slide occluder 1210 are placed into position on the peristaltic pump 1200. In step 3, the slide occluder 1210 is slid onto the peristaltic pump 1200 and moves the slide 1242 and lever 1240 in the reverse direction door and move button 1248 forward. The tube 1202 is retained near the front peristaltic pump 1200 as the slide occluder 1210 so that the tube 1202 is in the narrow part of the slit and clamped closed. In step 4, the door is closed. In step 5, the slide occluder 1210 is propelled outward by the movement of the button 1248 toward the rear of the peristaltic pump 1200. The button 1248 moves lever 1240, which moves the slide 1242 forward. Moving the slide occluder 1210 forward releases the pinch on the tube 1202 by the slide occluder 1202.

[000735] Figures 210 to 212 illustrate features to prevent the user from installing a tube without the correct slide occluder. A flap 1250 prevents a slide occluder 1210 from being installed that does not have a corresponding slot 1252. An occluder 1254 prevents the door 1212 from closing. The occluder 1254 is displaced by the slide occluder 1210 in step 3 of Figure 207.

[000736] Figures 213 to 220 illustrate how the peristaltic pump 1200 prevents a free-flow condition when the tube 1202 is loaded and/or removed. The port 1212 easily opens to a 90° angular position from the front of the peristaltic pump 1200. A small force can be applied to further rotate the port 1212, which forces the plunger 1222 and diaphragm valves 1224, 1226 to the open position. The movement of the port 1212 pulls the L-shaped cam followers 1218A to E toward the front and thereby lifts the plunger 1222 and the diaphragm valves 1224, 1226 of the tube 1202.

[000737] Figure 221 illustrates the ultrasonic air sensor 1228 that can detect air bubbles of a certain size in the fluid downstream of the diaphragm valve pump 1266. The pressure sensor 1260 can measure the static pressure in the fluid downstream of the pump . The pressure sensor 1260 and the air sensor 1228 can communicate with the pump controller.

[000738] Figure 222 to 223 shows two views of a peristaltic pump 754 according to an embodiment of the present description. The peristaltic pump 754 includes a port lever 755 and a port 756. Figure 224 shows the slide occluder 757 in an open position against the tube 758. The slide occluder 754 is loaded onto the slide occluder carrier 1312. The carrier of slide occluder 760 engages a pin 761 that is in mechanical communication with the plunger lift lever 759 in Figure 225. Figure 225 illustrates that because the door lever 755 is open (see Figure 244), a lift lever 759 plunger is not lifting the 1310 plunger and diaphragm valves. Figure 226 shows how the door lever 755 is open, how the conveyor 760 moves forward toward the door and moves the slide occluder 757 past the tube 758 so that the tube 758 is closed as it passes through the narrow section. of the slide occluder 757. At approximately the same time as the tube 758 is pinched closed by the slide occluder 757, the moving forward of the conveyor 760 rotates the pin 761 which moves the piston lift level 759 to lift the pistons 1310 and the pipe diaphragm valve 758 as shown in Figure 227. In Figure 228, the gate lever 755 is completely open and the conveyor 760 stops movement. As shown in Figure 229, the plunger lift lever 759 is in a stable central position that will keep the plunger 1310 out of the tube 758 when the gate lever 755 is completely opened.

[000739] Figures 230 to 233 illustrate a lock that can prevent the slide occluder carrier 760 from moving and closing the plungers 1310 and valves 1312 without the door 756 being closed first. Figure 230 shows door 756 open and released flap 1316 exposed. The locking pin 1318 is shown in the locked position which prevents the slide occluder carrier 760 from moving. A spring 1320 urges the locking pin 1318 toward the slide occluder carrier 760 and engages the locking pin in a corresponding hole when the slide occluder carrier 760 is in position.

[000740] Figures 231 to 233 show the sequence of door 756 opening and releasing the locking pin 1316 by removing the release tab 1316. As the tab is removed, the locking pin 1318 is propelled toward the occluder carrier of slide 760.

[000741] Figure 234 shows the door 756 open and the slide occluder 757 being lifted from the slide occluder carrier 760. The tube 758 is in the narrow section of the slide occluder 757 that clamps the tube 758 closed. Figure 235 illustrates the placement of tube 758 in the pump between the anvil plate 1324 and the plunger 1310 and valves 1312. Figure 236 shows the slide occluder 757 and the tube 758 completely installed in the pump 754, where the slide occluder 757 is closing tube 758 by clamping. Figure 237 shows door 756 and door lever 755 being closed, which slides slide occluder conveyor 760 toward the rear of pump 754. Movement of slide occluder conveyor 760 drives slide occluder 757 beyond tube 758 so that the tube is open and rotated pin 761 which in turn rotated plunger lift lever 759 which released plungers 1310 and valves 1312 to descend and close tube 7558. Figure 238 shows a front view of port 756 being closed.

[000742] Figures 239 to 245 show various views of the peristaltic pump of Figures 222 to 238 according to an embodiment of the present description. A 2001 engine rotates gears that, in turn, rotate a 772 cam shaft. As the 772 cam shaft rotates, the 2003, 2004, 2005, 2006, and 2007 cams rotate with the 772 cam shaft. cam follower 769, which pivots along a pivot 763 to move a diaphragm valve 770. The 2004 and 2006 cams engage cam followers 766 and 765, which pivot along pivot 763 to move a plunger 767. The 2007 cam engages cam follower 762 to move diaphragm valve 764. Additionally, cam 2005 engages cam follower 768. Cam 2005 is shaped so that engagement with cam follower 768 at least partially balances the torque ( for example, to reduce peak ringing). In some embodiments, cam 2005 and cam follower 768 are optional. The inlet valve 770 (which is a diaphragm valve), the plunger 767 and the outlet valve 764 (which is a diaphragm valve) can engage the tube 771 using the three or four stages of pumping action as described above . A bubble sensor 2008 can be used to distinguish between a bubble and a leaking valve 764 or 770 (e.g., diaphragm valves) as described above.

[000743] The rotation of the cam shaft 772 can be controlled by the engine 2001 so that at the same time as the fluid is compressed by the plunger 767, the output valve 764 is opened by a PID control loop to achieve a profile -Target discharge rate (e.g., smoothed discharge rate) as measured by the plunger position sensor. In some embodiments, a range of angles moves only the outlet valve (e.g., outlet diaphragm valve). In still further embodiments, in the four-stage pumping action described above, the movement of the plunger 767 is closed after the outlet valve 764 opens to achieve a target discharge rate profile (e.g., smoothed discharge rate) as measured. by the piston position sensor 767.

[000744] As is readily seen in Figure 241, cams 2002, 2003, 2004, 2005 and 2006 are shown as engaging cam followers 769, 766, 768, 765 and 762, respectively. Figure 242 shows a front view of the peristaltic pump including plunger 767 and diaphragm valves 764 and 770 positioned to engage tube 771.

[000745] A standard pipeline pump 1000 with an optical monitoring system is shown in Figure 251 and 252. The optical monitoring system comprises a camera 1010 with a field of view that may include part or all of the plunger 1004, a valve diaphragm 1002, a portion of the tube 1006, fiducial marks on the diaphragm valve 1014, fiducial marks on the plunger 1016, fiducial marks on the stop 1018, a light source (not shown) and a light guide 1012 for illuminating the surfaces facing camera 1010. The optical monitoring system may further comprise additional cameras 1010 with fields of view that include part or all of the plunger 1004, additional diaphragm valves 1002, a portion of the tube 1006, fiducial marks on the diaphragm valve 1014, fiducial marks on plunger 1016, fiducial marks on stop 1018, a light source (not shown) and a light guide 1012 for illuminating surfaces facing camera 1010. The optical monitoring system may additionally comprise one or more rear light sources 1102, rear light guides 1104, and a transparent plunger 1006 for illuminating the rear side of the tube 1006 relative to the camera 1010. The camera 1010 and lights can operate in a spectrum range from ultraviolet to infrared.

[000746] The optical system may further comprise a processor, memory and software that may allow images to be interpreted to provide a range of information about the status of the pump, piping and flow that includes, but is not limited to, the position of the plunger relative to the stop 1005, the position of the diaphragm valve relative to the stop 1005, the speed and direction of the plunger 1004 and the diaphragm valve 1002, the presence of the tube 1006, the presence of liquid or gas in the tube 1006, the presence of gas bubbles in tube 1006, the presence of deformations in tube 1006. The processor may additionally interpret plunger and valve position information to determine fluid flow rate, presence of an occlusion in the tube, presence of a leak in the piping.

[000747] The optical monitoring system recognizes and measures the positions of the plunger 1004 and valves 1002 relative to the anvil plate 1005. The anvil plate 1005 is the stationary part of the pump and elsewhere may be referred to as the opposing surface or occlusion bed. The pump controller can command the optical monitoring system to take an image using the camera 1010 and front or rear light sources. A processor located in the camera or elsewhere may process the image using software to identify the relative distance and orientation of the plunger 1004 and valves 1002 relative to the anvil plate 1005. In one embodiment, the machine vision software may identify elements 1002, 1004 and 1005 and their location in its field of view through an edge detection algorithm as described above. The detected edges can be assigned to each element 1002, 1004, and 1005 based on the edge location within the field of view. By way of example, an edge detected in the upper third of the field of view may be assigned as the anvil plate 1005, while an edge detected in the lower left quadrant may be assigned as the diaphragm valve 1002 if the camera 1010 is on the left side. as shown in Figure 251.

[000748] In another embodiment, the machine vision software can identify the diaphragm valve 1002, the plunger 1004 and the anvil plate 1005 and their location in its field of view with fiducial marks located on each of the elements 1002, 1004 and 1005. Each element may include one or more fiducial marks that are located within the field of view of the camera 1010. The fiducial marks will be assigned to each element 1002, 1004, 1005 based on the region in the field of view in which it is detected. . Considering the left camera 1010 in Figure 251, by way of example, fiducial marks in the lower left region can be assigned as the diaphragm valve 1002, while fiducial marks in the lower right region can be assigned as the plunger 1004 and fiducial marks in the upper region can be assigned as the anvil plate 1005. A single fiducial mark may allow the optical monitoring system to measure the relative movement of the diaphragm valve 1002 and the plunger 1004 to the anvil plate 1006. More than one fiducial mark on a single element may allow the optical monitoring system to identify elements that have rotated in their plane of motion. The processor may signal a warning or an alarm if one or more of the elements 1002, 1004 and/or 1005 have rotated beyond a permitted amount. Significant rotation may indicate a mechanical break in the diaphragm valve 1002 or plunger 1004 or that the camera has rotated in its mounting in the camera port 1020.

[000749] Machine vision software can identify fiducial elements by corresponding a stored model to the image. Vision software may be an off-the-shelf product such as Open Source Computer Vision referred to as OpenCV and available for download from the internet. Vision software can use the TemplateMatching function or module to identify fiducial marks from a stored template.

[000750] The machine vision software can then calculate the relative position and orientation of the orientation elements 1002, 1004 and 1005 from the observed location within the camera's field of view and the stored geometric data of the diaphragm valve 1002, plunger 1004, and anvil plate 1005. The locations and orientations determined by the machine vision software can then be passed to algorithms to identify specific conditions that include, but are not limited to, the following: diaphragm valve opening , diaphragm valve closing, plunger at a maximum stroke, plunger at a minimum stroke. Other algorithms may process the location and orientation data determined by machine vision to determine parameters including, but not limited to, the following, plunger speed, fluid flow rate, occlusion in the tube, air in the tube, external leaks. These conditions and parameters are determined in the same manner as they are determined from Hall effect sensors that measure the location of the plunger 1004 and the diaphragm valves 1002, which is described above.

[000751] In other embodiments, the machine vision software can identify the conditions and determine the parameters described above. In other embodiments, the relative position and orientation of the diaphragm valve 1002, the plunger 1004, and the anvil plate 1006 30 may be calculated by algorithms outside of the machine vision software.

[000752] Machine vision software or algorithms that process output from machine vision software may recognize numerous conditions including, but not limited to, the following: tubing is not present, tubing is not placed correctly, tubing is empty of fluid, the tubing is full of fluid, the tubing is deformed and a gas bubble is present in the liquid.

[000753] The optical monitoring system can calculate the tube volume with fewer assumptions with data from an additional camera 1011 mounted at a substantial angle to the camera 1010 as shown in Figure 252. The backlight 1102, the light guide 1104 may supply infrared illumination to the back of the plunger 1004. The plunger 1004 may be nylon or similar material that is transparent to infrared radiation. The plunger is uncoated in the field of view of the camera 1011 to provide a clear view of the tube through the plunger 1004 in the infrared spectrum. A machine vision software package may determine tube profiles 1006 from camera 1010 and profile from camera 1011. An algorithm may calculate a first tube thickness as seen by camera 1010 and a second distance as seen by camera 1011. The volume of the tube can then be calculated from the two distances and the known circumference of the tube. A comparison of the two distances and the circumference of the tube can identify buckling in the tube shape that would significantly change the volume of liquid in the tube.

[000754] The volume of fluid in tube 1006 may depend on the shape assumed by the filled tube when the diaphragm valves 1002 are closed. The shape of the pipe 1006 near the diaphragm valves 1002 may change after the pump is calibrated due to a number of factors including, but not limited to, changes in piping materials, changes in manufacturing, changes in humidity and temperature. The camera 1010 can observe the shape of the tube 1006 near the diaphragm valve 1002. The tube can be illuminated with visible or infrared light from the front or back. In a preferred embodiment, the tube may be backlit with infrared light. Backlighting here refers to placing the source of lighting on the opposite side of the tube 1006 from the camera 1010.

[000755] In one embodiment, machine vision software can detect the shape of the tube using edge detection. An algorithm can compare the observed tube shape with a shape stored in memory. In one embodiment, the algorithm may correct the volume of fluid per cycle to account for the changed tube shape. In another embodiment, the algorithm that evaluates the tube shape may signal a warning or alarm to a higher level algorithm. In another embodiment, the machine vision software may confirm an acceptable tube shape by attempting to match a model of the accepted tube shape to the image. Machine vision software or the next higher level of software control can signal a warning or alarm if an acceptable tube shape is not identified.

[000756] Cameras 1010, 1011 may include either CCD (charge-coupled device) or CMOS (Complementary Metal-Oxide Semiconductor) chips to convert light into electrical signals that can be processes to generate an image. An example of a camera is HM0357ATC00MA31 from Himax Imaging, Inc. of Irvine, California, USA. Cameras 1010, 1011 and lights 1012 can be turned on only while taking measurements in order to reduce power consumption.

[000757] The diaphragm valve 1002, the plunger 1004, the tube 1006 and the anvil plate 1005 can be illuminated from the front. Front lighting refers to a light source that is on the same side of the object of interest as the camera 1010 and supplies illumination to the camera 1010 by reflection from the object of interest. An embodiment for providing front illumination comprises a light bar 1012 that transmits light from LEDs mounted in the camera port 1020. An embodiment of the light bar 1012 is shown in Figure 253. Light is supplied to the end surfaces 1032 of the light bar from LEDs or other light sources mounted in the camera port 1020. The front surface 1030 and the back surface (not shown) are covered with a material that reflects the supplied light. In one embodiment, the front and back surfaces are covered with an aluminized tape. The holes 1036 provide a clear field of view for the cameras 1010. The light bar may include a surface around each hole 1036 that is roughened to provide a diffused light that illuminates the front of the diaphragm valve 1002, the plunger 1004, the tube 1006 and the anvil plate 1005. The area around the holes 1036 can be re-entered and then roughened to provide more diffused light.

[000758] It may be advantageous to provide backlighting or illumination from the opposite side of the tube 1006 in relation to the camera 1010. The backlighting may allow clearer visualization of the tube shape and/or the shape of the volume within the tube 1006. One embodiment places the rear light source on the back of the pump 1000. The rear light source 1102 may be an LED or other lighting that provides light in the ultraviolet, visible, and infrared range. A light guide 1104 may direct light to the rear of the plunger 1004. The plunger may be made of a material that is transparent to the spectrum of light emitted by the light source 1102. In one embodiment, the plunger is made of nylon and the light source 1102 provides infrared illumination, which the camera 1010 can detect. In some embodiments, the backlight may be a plurality of light sources. The plurality of light sources can be controlled and/or modulated so that only specific lights are turned on that are necessary to illuminate a pixel being exposed. For example, the camera may have a region of interest and only the lights necessary to illuminate the region of interest are turned on during the exposure time of pixels within the region of interest. In some embodiments, the lights may be rows and/or columns of lights and/or pixels of lights (e.g., an array of LED lights).

[000759] The spectrum of the rear light source 1102 and the camera 1010 can be selected to maximize the visibility of the fluid in the tube. In one embodiment, the spectrum may be broad to provide maximum light for viewing the tube. In another embodiment, a set of filters on the front of the rear light source 1102 emits a narrow band of the infrared spectrum that passes through the light guide 1104, the plunger 1004 and the tube 1006, but is absorbed by the liquid in the tube. The light source 1102 may also emit a narrow band of the infrared spectrum that passes through the light guide 1104. In another embodiment, filters to allow only the desired infrared band are on the front of the camera 1010.

ACOUSTIC VOLUME DETECTION

[000760] The following discussion describes acoustic volume detection that can be performed by a processor disclosed herein with a speaker and two microphones (e.g., a reference microphone and a variable volume microphone) of a peristaltic pump, for example, a peristaltic pump disclosed herein; AVS may be used to estimate liquid within a reservoir disclosed herein, to estimate an amount of liquid discharged from a reservoir disclosed herein, and/or to estimate a discharge rate of liquid from a reservoir disclosed herein. this document. Table 1 shows the definition of various terms as follows: TABLE 1.

[000761] The acoustic volume sensor ("AVS") measures the volume of fluid displaced by the non-liquid side of a reservoir in the AVS chamber, e.g., an acoustic housing or the interior of a reservoir, etc. The sensor does not directly measure the volume of fluid, however, it measures the variable volume of air, V2, inside the AVS chamber; If the total AVS chamber volume remains constant, the change in V2 will be the direct opposite of the change in fluid volume. The AVS chamber is the volume of air in fluid communication with a variable volume microphone beyond the acoustic port.

[000762] The air volume, V2, is measured using an acoustic resonance. A time-varying pressure is established at the fixed volume of the reference chamber, V1, using a loudspeaker. This pressure disturbance causes cyclical airflow in the acoustic port connecting the two volumes, which in turn causes a pressure disturbance in the variable volume. The system dynamics are similar to those of a Helmholtz oscillator; the two volumes act together as a "spring" and the air in the door connects the volumes as a resonant mass. The natural frequency of this resonance is a function of port geometry, sound speed, and varying volume. The gate geometry is fixed and the speed of sound can be found by measuring the temperature; therefore, given these two parameters, the variable volume can be found at the natural frequency. In some embodiments of the present disclosure, a temperature sensor is used inside the acoustic housing and/or inside the non-liquid side of a reservoir. In some embodiments, the temperature is assumed to be a predetermined fixed value, e.g., it is assumed to be room temperature, etc.

[000763] The natural frequency of the system is estimated by measuring the relative response of the pressures at the two volumes to different frequency perturbations created by the speaker. A typical AVS measurement will consist of taking an initial measurement. Liquid is then released from the liquid side of one or more reservoirs and delivered to the patient (after which a second volume measurement is made). The difference between these measurements will be the volume of liquid delivered to the patient. In some embodiments, a measurement will be made before filling the liquid side of the one or more reservoirs and/or before discharging the liquid, for example, when the syringe pump is pre-charged, to detect any failure of the fluid system.

[000764] An AVS measurement may occur according to the following actions: (1) the processor will power the AVS electronics, enable the processor ADC, and initialize an AVS algorithm; (2) an AVS measurement consists of collecting data from numerous different frequencies; (3) optionally measure temperature; and (4) then perform an estimation routine based on the collected data to estimate the volume of liquid on the liquid side of a reservoir.

[000765] To collect data at each frequency, the speaker is driven sinusoidally at the target frequency and measurements are made at the two microphones at an integer number of wavelengths, e.g., the reference microphone and the reference microphone. variable volume (as described above). Once the data has been collected, the processor disclosed herein performs a discrete Fourier transform algorithm on the data to transform the time series data from the microphones into a single complex amplitude. Integrity checks are performed on the data from the microphones to determine if the data is valid, for example, the response is in a predetermined phase and/or amplitude range of the acoustic frequency.

[000766] Frequency measurements are made at numerous different frequencies. The sine sweep is then used by the estimation routine to estimate the variable volume. After the estimation is completed, further integrity checks may be performed on the entire sine scan, including a secondary check by a processor disclosed herein.

[000767] In some embodiments, after a processor disclosed herein verifies measurement integrity, volume estimates are finalized and the sensor is turned off.

AVS RESONANCE MODEL

[000768] The governing equations for the AVS system can be found from first principles given a few simplifying assumptions. The system is modeled as two linearized acoustic volumes connected by an idealized acoustic door.

MODELING ACOUSTIC VOLUMES

[000769] The pressure and volume of an ideal adiabatic gas can be related by Equation (35) as follows:

[000770] where K is a constant defined by the initial conditions of the system. Equation 1 can be written in terms of an average pressure, P, and volume, V, and a small time-dependent perturbation on top of these pressures, p(t), v(t) as illustrated in Equation (36) 20 as follows:

[000771] The Differentiation Equation (36) results in Equation (37) as follows:

[000772] Equation (37) is simplified to Equation (38) as follows:

[000773] If acoustic pressure levels are much lower than ambient pressure, Equation (38) can be further simplified to Equation (39) as follows:

[000774] Using the adiabatic relationship, Equation (40) can be shown as follows:

[000775] Thus, the error assumption is shown in Equation 41 as follows:

[000776] A very high acoustic signal (for example, 120 dB) would correspond to a pressure sine wave with an amplitude of approximately 20 Pascals. Assuming that air under atmospheric conditions has the parameters of Y = 1.4 and P = 101325 Pa, the resulting error follows: on what

[000777] Applying the ideal gas law, P = ρRT and substituting pressure generates the result as shown in Equation (43) as follows:

[000778] This can be written in terms of the speed of sound in Equation (44) as follows:

[000779] And substituting Equation (44) into Equation (43) results in Equation (45) as follows:

[000780] The acoustic impedance for a volume is defined in Equation 46 as follows:

ACOUSTIC DOOR MODELING

[000781] The acoustic port is modeled assuming that all fluid in the port moves essentially as a rigid cylinder reciprocating in the axial direction. All fluid in the channel is assumed to progress at the same speed, the channel is assumed to be of constant cross-section, and the end effects that result from fluid entering and leaving the channel are neglected.

[000782] If it is assumed that laminar flow friction of the form , the friction force acting on the mass of fluid in the channel can be written: . A second order differential equation can then be written for the fluid dynamics in the channel as shown in Equation (47) as follows:

[000783] or in terms of volume flow rate as shown in Equation (48) as follows:

[000784] The acoustic impedance of the channel can then be written as shown in Equation (49):

SYSTEM TRANSFER FUNCTIONS

[000785] Using the port and volume dynamics defined above, the AVS system can be described by the following system of Equations 50 to 53:

[000786] An equation can be eliminated if p0 is treated as the input it replaces in as shown in Equations 54 to 56:

[000787] The relationship between the two volumes on each side of the acoustic door is referred to as the Transverse Door transfer function. This relationship is illustrated in Equation 5 (57) as follows: on what

[000788] This relationship has the advantage that the poles are dependent only on the variable volume and not on the reference volume. Note that the resonant peak is actually due to the zero inversion in the reference volume pressure response. This means that the pressure measurement in the reference chamber will have a low amplitude in the vicinity of the resonance, which can influence the noise in the measurement.

RESONANCE Q FACTOR AND PEAK RESPONSE

[000789] Resonance quality is the ratio of stored power to power loss multiplied by the resonant frequency. For a pure second-order system, the quality factor can be expressed as a function of the damping ratio illustrated in Equation (58):

[000790] The ratio of the peak response to the low frequency response can also be written as a function of the damping ratio shown in Equation (59):

[000791] This will occur at the damped natural frequency

ELECTRICAL AND MECHANICAL ANALOGIES

[000792] The acoustic resonator is analogous to either a spring mass damper system or an LRC circuit, for example, a resistor, inductor and capacitor coupled together in series, for example.

COMPUTATION OF THE COMPLEX RESPONSE

[000793] To implement AVS, the system needs to receive the relative response of the two microphones to the acoustic waveform adjusted by the speaker. This is accomplished by driving the speaker with a sinusoidal output at a known frequency; The complex response of each microphone is then found at the drive frequency. Finally, the relative responses of the two microphones are found and corrected to change the sampling of the analog-to-digital converter coupled to a processor disclosed herein.

[000794] Additionally, the total signal variance is computed and compared to the variance of the pure tone extracted using the discrete Fourier transform ("DFT"). This generates a measurement of how much of the signal power comes from noise or distortion sources. In some embodiments of the present disclosure, this value can be used to reject and repeat bad measurements.

COMPUTING THE DISCRETE FOURIER TRANSFORM

[000795] The signal from each microphone is sampled synchronously with the speaker output so that a fixed number of points, N, are taken per wavelength. The signal measured at each point n wavelength is summed to an integer number of wavelengths, M, and stored in an array x by an interrupt service routine ("ISR") on a processor disclosed herein after all data for that frequency have been collected.

[000796] A discrete Fourier transform is done on the data at the integer value corresponding to the driven frequency of the speaker. The general expression for the first harmonic of a DFT is as follows in Equation (61):

[000797] The product MN is the total number of points and the factor of 2 is added so that the resulting real and imaginary portions of the response correspond to the amplitude of the sine wave illustrated in Equation (62):

[000798] This real part of this expression is illustrated in Equation (63):

[000799] One can take advantage of the symmetry of the cosine function to reduce the number of computations required to compute the DFT. The above expression is equivalent to Equation (64) as follows:

[000800] Similarly, the imaginary portion of the Equation is illustrated in Equation (65) as follows:

[000801] which can be expressed as Equation (66):

[000802] The variance of the signal at that driven frequency is illustrated in Equation (67) as follows:

[000803] The tone variance is proportional to the acoustic power at the driven frequency. The maximum possible value of the real and imaginary portions of x is 211; This corresponds to half of an A/D range. The maximum value of pitch variance is 221; half the square of the AD range.

COMPUTATION OF TOTAL SIGNAL VARIANCE

[000804] A good measure of the integrity of a measurement is the ratio of the acoustic power at the driven frequency to the total acoustic power at all frequencies. The total signal variance is generated by the expression in Equation (68):

[000805] However, in some specific embodiments, the sums are performed in the A/D/interrupt service routine (ISR) where there are time constraints and/or all microphone data needs to be stored for later processing. In some embodiments, to increase efficiency, a pseudovariance is calculated based on a single average wavelength. The pseudovariance of the signal is calculated using the following relationship illustrated in Equation (69) as follows:

[000806] The result is in the units of square AD counts. The sum will be in the order of for a 12-bit ADC. If N < 27 =128 and M < 26 = 64, then the sum will be less than 243 and can be stored in a 64-bit integer. The maximum possible value of variance would result if the ADC oscillated between a value of 0 and 212 in each consecutive sample. This would result in a peak variance of so that the result can be stored at a maximum of Q9 resolution in a signed 32-bit integer.

COMPUTATION OF RELATIVE MICROPHONE RESPONSE

[000807] The relative response of the two microphones, G, is then computed from the complex response of the individual microphones illustrated in Equations 70 to 72:

[000808] The denominator of either expression can be expressed in terms of the reference tone variance computed in the previous section, illustrated as follows in Equation 73:

FIX FOR A/D DISTORTION

[000809] The speaker output can be updated at a fixed 32 times per sample. For example, as the drive frequency is changed, the speaker output frequency is also updated to maintain the fixed 32 cycles. The two microphones are sampled synchronously with the speaker output so that the sampling frequency remains within a fixed range of the drive frequency. Microphone A/D measurements, however, are not sampled simultaneously; The A/D ISR switches between the two microphones, taking a total of N samples per wavelength for each microphone. The result will be a phase shift between the two microphones. . To correct for this phase shift, a complex rotation is applied to the relative frequency response computed in the previous section.

[000810] To rotate a complex number one angle , the same is multiplied by . The result is illustrated in Equation (74) as follows:

TIME DELAYS

[000811] In some embodiments, one of the assumptions when deriving the AVS equations is that pressure is uniform across acoustic volumes. This assumption is true if the acoustic wavelength is large compared to the dimensions of the AVS chamber. The wavelength of a sound wave at a given frequency can be computed with the following Equation (75):

[000812] For example, the wavelength at 1 kHz is approximately 246 mm and at 5 kHz it is approximately 49.2 mm. The AVS chamber can be of a diameter such that the time delay associated with acoustic waves progressing through the volumes has a small but measurable effect. The effect can be modeled as a time delay (or time advance, depending on microphone orientation). The Laplace transform of a pure time delay, d, is illustrated in Equation (76) as follows:

[000813] The phase is influenced by the time delay, but not the magnitude of the system response. To correct for time delays, frequency response data can be corrected in advance by applying a model fitting algorithm. The complex amplitude can be rotated as a function of frequency according to the time delay equation above. The time delay can be assumed to be fixed, so that the rotation is only a function of frequency.

[000814] The time delay can be determined by running an optimization routine to find the time delay to minimize model fit error. Additionally or alternatively, there may be a "time advance" apparent in the data. For example, the reference microphone may experience a pressure disturbance slightly in advance of the acoustic port and the variable microphone may experience a pressure disturbance slightly behind the acoustic port. These "advances" and "delays" can be the effects of the propagation of pressure waves and are, in addition, "resonant" dynamics of the system, for example, these effects can be accounted for.

AMPLITUDE LEVELING

[000815] The amplitude of pressure measurements for a given speaker drive signal may vary from device to device and also as a function of the driven frequency. Device-to-device variations result from party-to-party differences in microphone and speaker sensitivities (e.g., approximately on the order of +/3 dB). Frequency-based dependencies result from variations in speaker sensitivity over frequency as well as from the expected dynamics of acoustic resonance.

[000816] To compensate, in some embodiments, speaker gain is automatically adjusted during AVS measurement. The speaker gains are stored in an array with an input for each of the sine sweep frequencies, for example, in memory 22 of Figure 2. The amplitude of the microphone signal (either the variable microphone or the reference microphone ) can be checked against the target amplitude. If it is either too large or too small a binary search routine can be employed to update the speaker gain at that frequency.

INDIVIDUAL MEASUREMENT INTEGRITY CHECK

[000817] It is possible for errors, component failures or external disturbances to result in an erroneous measurement. Component failures may include a distorted speaker output or faulty microphone. External disturbances may include mechanical shock to the pump housing or extremely loud external noise. These types of faults can be detected using two different health checks: microphone saturation and out-of-band variance.

[000818] The microphone saturation check observes the maximum and minimum values of the average wavelength signal for each microphone. If these values are close to the A/D limits, then a flag within a processor disclosed herein is set indicating that the measurement amplitude was out of range.

[000819] The out-of-band variance check compares the tone variance to the total signal variance for each microphone. In the ideal case, the ratio of these will be 1 — all the acoustic power will be at the activated frequency. In the event of shock or an extremely loud external acoustic noise, more power will be present at other frequencies and this value will be less than unity. In some embodiments, normal operation may be considered to have a ratio greater than 0.99.

[000820] In some embodiments, if an individual data point fails any of these integrity checks, it can be repeated or deleted without having to repeat the entire sine sweep to help facilitate AVS robustness. Other integrity checks can be done based on the full sine scan and are described later.

VOLUME ESTIMATION USING GENERALIZED SOLUTION WITH SCAN SINE

[000821] The resonant frequency of the system can be estimated using sweep sine system identification. In this method, the system's response to a sinusoidal pressure variation can be found at numerous different frequencies. This frequency response data can then be used to estimate the system transfer function using linear regression.

[000822] The transfer function for the system can be expressed as a rational function of s. The general case is expressed below for a transfer function with a nth-order numerator and a nth-order denominator. N and D are the coefficients for the numerator and denominator respectively. The equation was normalized so that the main coefficient of the denominator is 1, as illustrated in Equations (77) and (78): or

[000823] This equation can be rewritten in the form of Equation 79 as follows:

[000824] Equation (80) shows this sum in matrix notation:

[000825] Where k is the number of data points collected in the sweep sine. To simplify notation, this equation can be summarized using the vectors y illustrated in Equation (81). y = Xc (81).

[000826] Where y is k by 1, x is k by (m+n1) and c is (m+n1) by 1. The coefficients can be found using a least squares approach. The error function can be written as shown in Equation (82): e = y-Xc (82).

[000827] The function to be minimized is the weighted square of the error function; W is a kxk diagonal matrix, as illustrated in Equations 83 to 84.

[000828] The two central terms are scalars so that transposition can be neglected, as illustrated in Equations 85 to 87:

[000829] In some embodiments, complex transposition in all these cases is used. This approach can result in complex coefficients, but the process can be modified to ensure that all coefficients are real. Least square minimization can be modified to generate only real coefficients if the error function is changed to Equation (88).

[000830] Then the coefficients can be found with Equation (89):

VOLUME ESTIMATION USING SCAN SINE SOLUTION FOR A 2ND ORDER SYSTEM

[000831] For a system with a 0th order numerator and a second order denominator as shown in the transfer function illustrated in Equation (90).

[000832] The coefficients in this transfer function can be found based on the expression found in the previous section as follows Equation (92):

[000833] Where Equation (93) is as follows:

[000834] To simplify the algorithm, some of the terms can be combined as illustrated in Equations 94 to 96 on what

[000835] To find an expression for D in terms of the complex response vector G and the natural frequency , first divide X into its real and imaginary parts as illustrated in Equations (97) and (98), respectively, as follows:

[000836] The real and imaginary portions of the expression for D above then become Equations (99) and (100), respectively:

[000837] The combination of these terms generates the final expression for the matrix D. This matrix will contain only real values, as shown in Equation (101) as follows:

[000838] The same approach can be taken to find an expression for vector b in terms of G and ω. The real and imaginary parts of y are illustrated in Equation 102 to 103.

[000839] The combination of these two generates the expression for vector b illustrated in Equation 104 as follows:

[000840] The next step is to invert the matrix D. The matrix is symmetric and positive definite so that the number of computations required to find the inverse is reduced from the general 3x3 case. The general expression for a matrix inverse is shown in Equation (105) as:

[000841] If D is expressed as in Equation (106):

[000842] then the adjugated matrix can be written as in Equation (107) as follows:

[000843] Due to symmetry, only the upper diagonal matrix needs to be calculated. The Determinant can then be computed in terms of the adjugated matrix values, taking advantage of the zero elements in the original array as illustrated in Equation (108) as follows:

[000844] Finally, the inverse of D can be written in the form shown in Equation (109):

[000845] In some embodiments, the value in Equation (110) can be solved:

[000846] So that Equation (111) is used:

[000847] To obtain a quantitative assessment of how well the data fits the model the original expression for the error as shown in Equation (112) is used:

[000848] This can be expressed in terms of the matrix D and the vectors b and c illustrated in Equation (113): on what:

[000849] In some embodiments, comparing the errors of different sine sweeps, the fitting error is normalized by the square of the weighting by the matrix as follows in Equation (116), where h is a scalar:

VOLUME ESTIMATION USING ESTIMATE VOLUME WITH SCAN SINE

[000850] Model tuning can be used so that the resonant frequency of the gate can be extracted from the sine sweep data. The volume delivered can be related to this value. The ideal relationship between the two can be expressed by the relationship illustrated in Equation (117):

[000851] The speed of sound will vary with temperature, so it is useful to divide the temperature effects as shown in Equation (118):

[000852] The volume can then be expressed as a function of the measured resonant frequency and temperature, illustrated in Equation (119) as follows:

[000853] Where C is the calibration constant illustrated in Equation (120) as follows:

VOLUME ESTIMATION USING SCAN VOLUME ESTIMATION INTEGRITY CHECKS

[000854] In some embodiments, a second set of integrity checks may be performed from the output of the mode adjustment and volume estimation routines (the first set of checks are done at the FFT level). Checks can be made either through redundancy or through range checking for various values, such as: (1) model fit error, (2) estimated damping ratio, (3) estimated transfer function gain, ( 4) estimated natural frequency, (5) estimated variable volume, and (6) AVS sensor temperature.

[000855] Additionally, portions of the AVS calculations may be done redundantly on a processor disclosed herein using an independent temperature sensor and an independent copy of the calibration parameters to protect against RAM failures, in some cases. specific modalities.

VOLUME ESTIMATION USING DISPOSABLE DETECTION WITH SCAN SINE

[000856] The presence of disposables, for example, cartridges or reservoirs that are attachable, can be detected using a magnetic switch and mechanical locking, in some specific embodiments. However, a second detection method can be used to 1) differentiate between the bomb being attached to a disposable and a charger, and 2) provide a recovery to the primary detection methods.

[000857] If the disposable is not present, the variable volume, V2, is effectively too large. As a result, there will be a normal signal from the reference microphone, but there will be little signal from the variable microphones. If the average amplitude of the reference microphone during a sine sweep is normal (this verifies that the speaker is working) and the average amplitude of the variable microphone is small, a flag is set in a processor disclosed herein that indicates that the disposable is not present.

IMPLEMENTATION DETAILS - SIZING V1 IN RELATION TO V2

[000858] Sizing V1 may include exchanging acoustic volume with the relative position of the poles and zeros in the transfer function. The transfer function for both V1 and V2 is shown in relation to the speaker volume offset as illustrated in Equations 121 to 124, as follows: on what

[000859] As V1 is increased, the gain decreases and the speaker needs to be driven at a higher amplitude to obtain the same sound pressure level. However, increasing V1 has the benefit of moving the complex zeros in the p1 transfer function toward the complex poles. In the limiting case where then and you get polzero cancellation and a flat response. Increasing V1 therefore reduces both the resonance and the notch in the p1 transfer function and moves the p2 poles in the direction of íiJ ; the result is a lower sensitivity to the measurement error during the calculation of the p1/p2 transfer function.

DEPLOYMENT DETAILS SERVING

[000860] Higher frequencies may alias to the frequency of interest. The jagged frequency can be expressed in Equation (125) as follows:

[000861] Where is the sampling frequency, is the frequency of the noise source, is a positive integer and is the jagged frequency of the noise source.

[000862] The demodulation routine can filter noise except at the specific demodulation frequency. If the sample frequency is dynamically adjusted to be a fixed multiple of the demodulation frequency, then the noise frequency that can alias to the demodulation frequency will be a fixed set of harmonics of that fundamental frequency.

[000863] For example, if the sampling frequency is 8 times the demodulation frequency, then the noise frequencies that can alias for that frequency are

[000864] where For , if you could have the series

SOURCES OF AVS MEASUREMENT ERROR - AVS CAMERA MOVEMENT

[000865] In some embodiments, one of the assumptions of AVS measurement is that the total AVS volume (V2 plus the volume occupied by the other components) is constant. However, if the AVS housing flexes, the total volume of the AVS chamber may change slightly and affect the differential volume measurement. In some embodiments, maintaining the volume contribution, error is kept less than 1.0% of the fluid delivery.

SOURCES OF AVS MEASUREMENT ERROR - EXTERNAL NOISE

[000866] In some embodiments, external noise sources can be filtered.

SOURCES OF AVS MEASUREMENT ERROR - MECHANICAL SHOCK

[000867] Mechanical shock to the pump housing during an AVS measurement will affect microphone measurements and may result in an error in the frequency response data. This error, however, is detectable using the out-of-band variance check in the demodulation routine by a processor disclosed in this document. If such an error is detected, the data point may be repeated (e.g., another sample is taken) resulting in little or no effect on the resulting AVS measurement.

SOURCES OF AVS MEASUREMENT ERROR - AIR IN AVS CHAMBER

[000868] One mechanism for an air bubble to affect the AVS measurement is through a secondary resonance. This secondary resonance is the 4th order of the system and, depending on the frequency and magnitude of the secondary resonance, it may cause some error if the estimate is using a 2nd order model.

SOURCES OF AVS MEASUREMENT ERROR - ELECTRICAL COMPONENT FAILURE

[000869] In general, failure of an electrical component will result in increased signal or harmonic distortion. In either case, the failure would be detected by AVS integrity checks and the measurement invalidated.

[000870] One exception that has been identified is a failure of the oscillator used to control the DAC and ADC. If this oscillator were to move away from tolerance, it would introduce a measurement error that may not be detected by the low-level integrity check (it would be detected in an extreme case by the volume integrity checks described above). To protect against these failures, in some embodiments, the oscillator is checked against an independent clock whenever an AVS measurement is indicated.

L-SHAPED CAM FOLLOWER PERISTALTIC PUMP

[000871] Figures 255 to 302 show another embodiment of a peristaltic pump 2990.

[000872] Figure 255 illustrates a peristaltic pump 2990 comprising a pumping mechanism 3000, display 2994, buttons 2996, chassis 2992 and claw 2998. The chassis 2992 includes an extension 2992A above the pumping mechanism 3000 that diverts liquid towards recoil from the inside of the mechanism.

[000873] Figures 256A to B illustrate a peristaltic pumping mechanism 3000 that has L-shaped cam followers 3090, 3100, 3110 (see Figure 274) in an enlarged view. A housing, optionally composed of two halves, 3005, 3010 provides attachment points for a cam shaft 3080, a main PCB 3002, a cam follower shaft 3120, a gear head installation 3070, and pivot points 3010A for mounting a port 3020. The two halves 3005, 3010 may be an upper half 3010 and a lower half 3005. The sensor housing 3015 may be mounted to the housing halves 3005, 3010 and provide an attachment point for a sensor mount 3060 and a 3130 rotation sensor board (Figure 257). A 3066 in-line air detector (see Figure 257) and a 3068 pressure sensor (Figure 257) can be attached to the 3060 sensor assembly.

[000874] Figure 257 illustrates the pumping mechanism 3000 having L-shaped cam followers 3090, 3100, 3110 (see Figure 274) with the port installation 3021 fully open and the infusion tube 3210 and the occluder. slide 3200 mounted to door 3020. Door installation 3021 is mounted to housing halves 3010, 3005 (Figure 256A) via two hinges 3010A and a pivot pin 3012 (Figure 258). In the open position, the port installation 3021 may provide convenient receiving elements, which may serve to locate an infusion tube 3210 in the port installation 3021. The receiving elements may locate the infusion tube 3210 so that it interfaces appropriately. or align with the sensors and active elements of the peristaltic pump 2990. The sensors may, for example, include a pressure sensor 3068 (Figure 257) and/or an in-line air sensor 3066 (Figure 257). Active elements may include, for example, plunger 3091, inlet valve 3101, and outlet valve 3111 (Figure 260). Plunger 3091, inlet valve 3101, and outlet valve 3111 may be referred to herein simply collectively as active elements 3091, 3101, 3111. Inlet valve 3101 and outlet valve 3111 may be referred to herein. collectively as valves 3101, 3111. Active elements 3091, 3101, 3111 may be included respectively in a portion of the L-shaped cam followers 3090, 3100, 3110. Receiving elements in port 3020 may include a or more of the following: 3020K door slots (see Figure 259), 3062A clips (Figure 257), 3024 clip inserts (Figure 257), 3022 plate (Figure 257). The press 3022 may be a tube retainer (i.e., a press 3022 configured to receive a tube, such as an intravenous infusion tube). In some embodiments, the press 3022 is an infusion tube retainer (i.e., a press 3022 configured to receive an infusion tube). The press 3022 may define a deep cavity or groove to receive an infusion tube 3210. The clamps 3062A (Figure 257) and 3024 (Figure 257) may be manufactured from any suitable non-deformable, minimally or non-compliant material. The 3062A clips are preferably molded from plastic such as nylon, but many other materials including ABS plastic, aluminum, steel and ceramic can be used.

[000875] The door installation 3021 (Figure 257) may include a receiving element for the slide occluder 3200. The slide occluder receiving elements 3200 in the door installation 3021 may retain the slide occluder 3200 in a position so that the slide occluder 3200 enters a receiving opening in the pump body 3001 (Figure 265). Some of the 3200 slide occluder receiving elements may include features that prevent the infusion set from being loaded incorrectly. In some embodiments, a split port conveyor 3040 includes a slot for receiving the slide occluder 3200 and retaining it perpendicular to the infusion tube 3210 as the port assembly 3021 is closed against the pump body 3001. The split conveyor port 3040 may include tabs 3040C (Figure 259) that allow the slide occluder 3200 to be inserted only so that interruptions 3200A (Figure 261) align with the tabs 3040C (as seen in Figure 259). In another embodiment, the port 3020 may include tabs 3020F (Figure 262, 263) that allow the slide occluder 3200 to be inserted only so that the stops 3200A (Figure 261) align with the tabs 3020F (Figure 262). The port 3020 (Figure 259) may include tabs 3020D (Figure 259) that prevent the slide occluder 3200 (Figure 259) from being inserted with the tab 3200B (Figure 259) in a desired orientation. The combination of the tab 3020D and any of the tabs 3020F (Figure 262) located on the port 3020 and/or the tabs 3040C on the port split conveyor 3040 (Figure 259) may allow the slide occluder 3200 (Figure 261) to be inserted only in one orientation and thereby force the correct orientation between the infusion set and the pumping mechanism 3000. The plate 3022 (Figure 257) can receive the infusion tube 3210 and provides an overall "U" shape to restrict the infusion tube 3210 according to a plunger 3091 deforms the infusion tube 3210 during pumping.

[000876] Figure 264 illustrates, in an enlarged view, the door installation 3021 including a lever 3025 (i.e., a lever handle 305) and a split conveyor 3041 (i.e., a conveyor) comprised of two parts, a door split conveyor 3040 and a body split conveyor 3045. The receiving elements 3062, 3022 of the infusion tube 3210 (Figure 260), 3024 (Figure 257) can be mounted respectively in the recesses 3020A, 3020B, 3020E (Figure 264) of door 3020. Door installation 3021 may include a door split conveyor 3040 that is connected to lever 3025 via a link 3035 (Figure 292). The door installation 3021 may also include a door spring 3032 (Figure 264). Door spring 3032 may be a substantially flat sheet of resilient material such as spring steel. The door spring 3032 may be pressed against the door 3020 by a latch pin 3034 as the lever 3025 engages the body pins 3011 (Figure 297) in the pump body 3001 and drives the latch pin 3034 toward the pump body. 3001. Referring to Figure 297, latch pin 3034 may move along a slot 3020C in door 3020 as latch hooks 3025C engage body pins 3011.

[000877] In Figure 265, door installation 3021 is opened and lever 3025 is retracted. The main PCB 3002, which includes the control processors and some sensors, is shown attached to the top of the upper housing 3010. A motor 3072 and a gear head 3070 are shown in position at one end of the upper housing 3010. The sensor installation rotation mechanism 3130 may be mounted in the lower housing half 3005. The pump body 3001 may comprise housing halves 3005, 3010, the rotational and reciprocating mechanisms within housing halves 3005, 3010, the motor 3072 and gearbox 3070, the sensors and the structure on which the above components are mounted.

[000878] Figure 260 illustrates a portion of the peristaltic pump 2990 (Figure 255) having L-shaped cam followers 3090, 3100, 3110 (see Figure 274) with the port 3020 open and with some elements removed to reveal the cam shaft 3080, the plunger 3091 and the valves 3101, 3111. The engine 3072 may drive the cam shaft 3080 through the gearbox 3070. The engine 3072 may have a drive shaft. In such embodiments, the speed and/or position of the drive shaft can be controlled. In some embodiments, the motor 3072 is a brushless DC servo motor 3072, controlled by a motor controller 3430 (see Figure 325B) that may be mounted on the main PCB 3002. In alternative embodiments, the motor 3072 may be a motor 3072 stepper, a 3072 DC brushed motor, or a 3072 AC motor with the appropriate controller.

[000879] The motor 3072 can be fixedly coupled to the gearbox 3070 allowing the motor/gearbox unit to be fixed as a unit to the camshaft 3080 and the upper housing 3010. The gear reduction of the gearbox gears 3070 can increase torque, while also increasing the number of engine revolutions 3072 per rotation of cam shaft 3080 (Figure 260). In one embodiment, the 3070 gearbox has a reduction ratio of 19:1. Gear reduction allows reasonable resolution in camshaft position 3080 (Figure 260) with a relatively small number of Hall sensors in engine 3072. In some embodiments, three Hall sensors and eight coils produce twenty-four crossovers per revolution. The twenty-four crossovers combined with a 19:1 gear ratio provides an angular resolution of better than 0.8° in the 3080 cam axis orientation (Figure 260).

[000880] The orientation of the cam shaft 3080 (Figure 260) can be directly measured with a rotation sensor 3130 (Figure 257) that detects the position of the magnet 3125 (Figure 260) at the end of the cam shaft 3080 (Figure 260) . In one embodiment, sensor 3130 is a single-chip magnetic rotary encoder IC that employs 4 integrated Hall elements that sense the position of magnet 3125 (Figure 260), a high-resolution analog-to-digital converter, and a power management controller. smart power. Magnetic field, alarm bits, and angular position information can be transmitted over a standard 3-wire or 4-wire SPI interface to a host controller. An example of a rotary encoder is model AS5055 manufactured by Austriamicrosystems of Austria which provides 4096 increments per rotation.

[000881] The movements of the valves 3101, 3111 and the piston 3091 are controlled by the cam shaft 3080. As best seen in Figure 266, the rotation of the cam shaft 3080 causes the rotation of individual cams 3083, 3084, 3082, which , in turn, deflects a roller end 3092, 3102, 3112 (Figure 274) of the L-shaped followers 3090, 3100, 3110 (Figure 274) downward.

[000882] The plunger 3091 is spring loaded so that the cam 3083 lifts the plunger 3091 in the direction of retreat relative to the tube 3210 (when the door 3020 is closed). Springs 3091 drive plunger 3091 toward tube 3210 and cam 3083 leaves the cam follower of 3091 to set a period of pressurization. The position of plunger 3091 during the pressurization period is used as a baseline to estimate how much fluid is in tube 3210 so that the process can estimate how much fluid is discharged when outlet valve 3111 is open. This process is shown in Figure 197.

[000883] Figure 266 shows an actuator mechanism 3081 that includes a cam shaft 3080, an outlet valve cam 3084, a plunger cam 3083, and an inlet valve cam 3082. The outlet valve cam 3084, the Plunger cam 3083 and inlet valve cam 3082 may be collectively referred to herein as simply cams 3084, 3083, 3082. Figure 271 shows a profile of outlet valve cam 3084, Figure 272 shows a profile of the cam 3083 and Figure 273 shows a profile of the 3082 output valve cam.

[000884] Referring now to Figure 274, the L-shaped cam followers 3090, 3100, 3110 rotate about a cam follower axis 3120, so that the downward movement of the roller end 3092, 3102 , 3112 may cause active elements 3091, 3101, 3111 to pull in the direction of retreat from an infusion tube 3210 (Figure 276). The tilt members 3094, 3104, 3114 in each of their respective L-shaped cam followers 3090, 3100, 3110 can drive the rollers 3092, 3102, 3112 in each of their respective L-shaped cam followers 3090 , 3100, 3110 upward against cams 3083, 3082, 3084 for each of their respective L-shaped cam followers 3090, 3100, 3110 (Figure 260). Tilt members 3094, 3104, and 3114 may also drive active ends 3091, 3101, 3111 toward an infusion tube 3210 (Figure 276). Tilt members 3094, 3104, 3114 may be torsion springs.

[000885] Figure 276 shows a cross-sectional view in which the operating member 3094 for the L-shaped cam follower of the plunger 3090 is a torsion spring and is driving the roller 3092 of the L-shaped cam follower of the plunger 3090 against the cam 3083. The operating member 3094 is also pushing the plunger 3091 of the L-shaped cam follower of the plunger 3090 towards the infusion tube 3210.

[000886] As mentioned above, the profiles of the output valve cam 3084, the plunger cam 3083 and the inlet valve cam 3082 are depicted in Figures 271 to 273. These profiles produce a valve sequence similar to that represented graphically in Figure 197. Cams 3084, 3083, 3082 can be connected to the 3080 cam shaft in any of the standard methods, including adhesive, press fit, keyed shaft. In some embodiments, cams 3084, 3083, 3082 may be physically integrated with cam shaft 3080 as a single piece. In some embodiments, cams 3084, 3083, 3082 have a key slot 3082A, 3083A, 3084A and are pressed onto cam shaft 3080 against a shoulder (not shown) with a key (not shown) to securely lock the cams. 3084, 3083, 3082 of rotation about the cam shaft surface 3080. A circle clamp 3085 for retaining the cams 3084, 3083, 3082 in position along the geometric axis of the cam shaft 3080 may also be included. Cam shaft 3080 may be mounted in upper and lower housings 3005, 3010 by bearings 3086 (Figure 278). In one embodiment, the bearings 3086 are sealed roller bearings.

[000887] Figure 274 illustrates the plunger L-shaped cam followers 3090, the valve L-shaped cam followers 3100, 3110 and the cam follower shaft 3120 in an enlarged view. The L-shaped cam follower of the 3090 plunger and the L-shaped cam follower of the 3110 outlet valve are shown respectively in Figures 267 to 268 and Figures 269 to 270. The L-shaped cam followers 3090, 3100, 3110 are mounted on the cam follower shaft 3120 and can rotate freely on the cam follower shaft 3120. Rotation of the L-shaped cam followers 3090, 3100, 3110 on the cam follower shaft 3120 can be facilitated by bearings. In some embodiments, the bearings may be solid flanged bushings 3095, 3105, 3115 pressed into the L-shaped frames 3093, 3103, 3113 of the L-shaped cam followers 3090, 3100, 3110. The bearings may be any bushing. low friction materials including, but not limited to, bronze, brass, plastic, nylon, polyacetal, polytetrafluoroethylene (PTFE), ultra high molecular weight polyethylene (UHMWPE), rulon, PEEK, urethane and vespel. The flanges on bushings 3095, 3105, 3115 can serve as axial bearing surfaces between adjacent L-shaped cam followers 3090, 3100, 3110 and between valve L-shaped cam followers 3100, 3110 and the housing halves 3005, 3010 (Figure 278). The flanges on bushings 3095, 3105, 3115 (Figure 274) can also serve to properly separate the live ends 3091, 3100, 3111 (Figure 274) from the L-shaped cam followers 3090, 3100, 3110 (Figure 274). relative to board 3022 (Figure 257) in port installation 3021 (Figure 257).

[000888] The cam follower shaft 3120 (Figure 274) may include end sections 3120A (Figure 274) that are eccentric with respect to the center section 3120B (Figure 274) of the cam follower shaft 3120 (Figure 274). The position of the cam follower shaft 3120 (Figure 274) relative to the cam shaft 3080 (Figure 260) and/or the plate 3022 (Figure 260) can be finely adjusted by rotating the eccentric end 3120A (Figure 274). Rotating the eccentric end 3120A (Figure 274) may allow adjustment of the clearance between the rollers 3092, 3102, 3112 (Figure 274) and the cams 3084, 3083, 3082 (Figures 271 through 273) on the cam shaft 3080 (Figure 260). .

[000889] The end section 3120A of the cam follower shaft 3120 (Figure 274) may include a feature 3120C for receiving a tool such as a screwdriver, hex wrench or other tool with the ability to apply a torque to the follower shaft cam 3120 (Figure 274). In some embodiments, feature 3120C may be a slot sized to accept a flat head screwdriver. Eccentric ends 3120A fit into holes formed by interruptions 3005D, 3010D (see Figure 278) in housing halves 3005, 3010 respectively. In one embodiment, the holes formed by interruptions 3005D, 3010D (Figure 278) do not connect the cam follower shaft 3120 (Figure 274) in order to allow adjustment. A claw element may be added to secure the rotary position of the 3120 cam follower shaft (Figure 274). In some embodiments, the gripper element is a fastener screw threaded into a threaded hole in the end section 3120A.

[000890] The L-shaped cam followers 3090, 3100, 3110 (Figure 274) or actuators may each comprise contact elements which in the example embodiment are rollers 3092, 3102, 3112 touching cams 3084, 3083 , 3082 (Figures 271 to 273). The L-shaped cam followers 3090, 3100, 3110 may also each comprise an operating member 3094, 3104, 3114 that drives the contact element toward the surface of the cams 3084, 3083, 3082. L-shaped cams may also each comprise an L-shaped frame 3093, 3103, 3113 that includes a bore, which is mounted on a cam follower shaft 3120. Frames 3093, 3103, 3113 may connect the rollers 3092, 3102, 3112 to the active elements 3091, 3101, 3111. The active elements 3091, 3101, 3111 may, in turn, touch the infusion tube 3210 (Figure 276). L-shaped cam followers 3090, 3100, 3110 (Figure 274) may additionally include flanged bushings 3095, 3105, 3115 mounted in the bore of respective frames 3093, 3103, 3113 (Figure 274).

[000891] In some embodiments, and referring now to Figure 274, the rollers 3092, 3102, 3112 may rotate around an axis 3096, 3106, 3116 that is mounted on structures 3093, 3103, 3113. In other embodiments, any different type of suitable contact element may be used.

[000892] In some embodiments, active elements 3091, 3101, 3111, or the inlet valve 3101, the plunger 3091, an outlet valve 3111, may be formed as part of the L-shaped cam followers 3090, 3100, 3110 (Figure 274). In some embodiments, the active elements 3091, 3101, 3111 may be removably attached to structures 3093, 3103, 3113 of each L-shaped cam follower 3090, 3100, 3110 (Figure 274). In some embodiments, active elements 3091, 3101, 3111 (Figure 274) may be mechanically affixed with screws or any other suitable fastener. In other embodiments, the active elements 3091, 3101, 3111 (Figure 274) may include studs that pass through holes in structures 3093, 3103, 3113 (Figure 274) and are held in place with nuts, or the active elements 3091, 3101 , 3111 (Figure 274) may include plastic studs that fit into receiving elements in structures 3093, 3103, 3113 (Figure 274). In some embodiments, the active elements 3091, 3101, 3111 may be fixedly coupled to the structures 3093, 3103, 3113 by another suitable or obvious coupling method.

[000893] Induction members 3094, 3104, 3114 (Figure 274) can drive the L-shaped cam followers 3090, 3100, 3110 (Figure 274) against the cam surface of the cams 3084, 3083, 3082 (Figures 271 to 273) and in the direction of the plate 3022 (Figure 260) and the infusion tube 3210 (Figure 276). In some embodiments, the induction members 3094, 3104, 3114 (Figure 274) are coiled torsion springs that surround the section of structures 3093, 3103, 3113 (Figure 274) that includes the perforation. In such embodiments, a portion of the torsion springs may press against the portion of the frames 3093, 3103, 3113 of the L-shaped cam followers 3090, 3100, 3110 (Figure 274) between the bore and the rollers 3092, 3102, and 3112 The other portion of each torsion spring may contact the fixed frame of the peristaltic pump 2990 (Figure 255). In some such embodiments, the attached structure may be a spring retainer or operating member 3140 (Figures 275, 276) which may include a slot 3140A for capturing the torsion spring portion. A retainer screw fastener 3142 (Figure 275) may be rotated to move the spring retainer or operating member 3140 within the upper housing 3010 and apply a load against the induction members 3094, 3104, 3114. In some rotating positions of cams 3084, 3083, 3082 (Figures 271 to 273), the load applied to the operating member 3094, 3104, 3224 may, in turn, be applied by the active ends 3091, 3101, 3111 to the infusion tube 3210. The load Compressive pressure of each of the active ends 3091, 3101, 3111 (Figure 274) on the infusion tube 3210 can be adjusted by turning the corresponding retainer screw fastener 3142.

[000894] In other embodiments, the induction members 3094, 3104, 3114 (Figure 274) may be coil springs that are located between the L-shaped cam followers 3090, 3100, 3110 (Figure 274) and the body frame of pump 3001. The coil springs may be located so that they drive one end of the L-shaped cam followers 3090, 3100, 3110 (Figure 274) toward the cams 3082, 3083, 3084 (Figure 271 to 273) . The coil springs can also drive the active elements 3091, 3101, 3111 of the L-shaped cam followers 3090, 3100, 3110 (Figure 274) toward the plate 3022 (Figure 260). An arrangement of coil springs and L-shaped cam followers 3090, 3100, 3110 is shown in Figures 205, 206, 219, 220.

[000895] Figure 276 shows a cross-section of the pump mechanism 3000 including cuts of the plunger cam 3083, the plunger 3091 and the plate 3022. The cam shaft 3080 rotates the plunger cam 3083 which is keyed to the shaft at 3084A. Cam 3083 displaces cam contact element or cam roller 3092, which is part of the L-shaped cam follower 3090 of the plunger. The L-shaped cam follower 3090 of the plunger rotates about the cam follower axis 3120. The L-shaped cam follower 3090 of the plunger 3091 is retained against the plunger cam 3083 by the operating member 3094. A portion end 3094A of operating member 3094 contacts frame 3093, while the free end of operating member 3094B contacts spring retainer or operating member 3140. As shown in Figure 276, plunger 3091 can compress the infusion tube 3210 against plate 3022. Plunger 3091 may retract from plate 3022 when plunger cam 3083 depresses cam roller 3092.

[000896] Figure 277 shows a cross-section of the plunger 3091, the plate 3022 and the infusion tube 3210 at the bottom of the plunger stroke 3091. At the top of the plunger stroke 3091, the infusion tube 3210 may be substantially uncompressed and may have a nominally round cross-section that contains a maximum volume. Referring now also to Figure 276, the pumping mechanism 3000 maximizes the pumping per stroke by allowing the infusion tube 3210 to be substantially completely filled at the top of the plunger 3091 stroke and minimizing the volume within the infusion tube. 3210 at the bottom of the plunger stroke 3091. The amount of volume pumped may be impacted by the shape of the plunger 3091, the stroke length of the plunger 3091, and the shape of the plate 3022. The design of the plunger 3091 and the plate 3022 may be selected to balance the increased volume against greater loads on plunger 3091. In some embodiments, plunger 3091 and plate 3022 are designed to prevent crushing of the walls of infusion tube 3210 by providing a gap between plunger 3091 and plate 3022 that is slightly greater than twice the wall thickness of the 3210 infusion tube.

[000897] In some embodiments, the plunger cam 3083 and the plunger L-shaped cam follower 3090 may be designed to provide a minimum clearance 3022G between the plunger tip 3091B (e.g., a rounded tip) and the 3022D plate background. In one example, the free space 3022G is 2 to 3 times the wall thickness of the infusion tube 3210 and sufficient so that the walls of the infusion tube 3210 do not touch between the plunger tip 3091B and plate bottom 3022D. In one example, the free space 3022G between the plunger tip 3091B and the bottom of the plate 3022D is approximately 0.12 cm (0.048 inch), which is 9% greater than twice the wall thickness of an exemplary infusion tube 3210 In another example, the free space 3022G may be as small as 2% greater than twice the wall thickness of an exemplary infusion line 3210. In another example the free space 3022G may be as large as 50% greater than twice the wall thickness of a 3210 infusion tube.

[000898] In some embodiments, the dimensions of the plate 3022 and the plunger tip 3091B are selected to provide a free space 3022G that is 2 to 3 times the wall thickness of a single wall of the infusion tube 3210. In one example, the free space 3022G between the plunger tip 3091B and the plate 3022 is 8% to 35% greater than twice the wall thickness of an exemplary infusion tube 3210. The free space 3022G can allow the sides of the infusion tube 3210 fold without pinching and closing the fold. In some embodiments, the plunger tip 3091B has a radius of 0.13 cm (0.05 inch) and sides 3091C that diverge from each other at an angle of 35'. The sides 3091C may satisfy the radius of the plunger tip 3091B at a tangent. The length of the 3091B plunger tip can be 0.29 cm (0.116 inch). The plate bottom 3022D may be flat and have a curved portion 3022C on each side. The bottom of the plate 3022D forms a cavity so that it is a tube retainer 3022. The length of the bottom of the plate 3022D and the radii of the curved portions 3022C are selected to maintain a free space 3022G between the plunger tip 3091B and the plate 3022 which is more than twice the wall thickness of the infusion tube 3210. In one example, the plate bottom 3022D is 13 cm (0.05 inch) long and each radius of the curved portions 3022C is 15 cm (0.06 inch). Side 3022B is angled to the receding direction of plunger 3091. The shorter side 3022E is nearly vertical. The side 3022F is at a less pronounced angle than the plunger walls 3091C to allow the plunger tip 3091B to enter the plate 3022 since the port installation 3021 is closed.

[000899] The plunger 3091 and the plate 3022 may include two substantially flat sections 3091A and 3022A that provide a mechanical stop (i.e., 3091A and 3022A may be contact sections). Flat sections 3091A and 3022A may also be referred to herein as stops 3091A and 3022A. Mechanical stops 3091A, 3022A ensure that tube 3210 is deformed by about the same amount with each actuation of plunger 3091. As described elsewhere, the volume is determined from the change in position of plunger 3091 at the beginning of the travel stroke at the end of the course. The plunger cam profile 3083 may be designed to lift the roller 3092 when the flat section 3091A contacts the plate 3022 to 3022A when discharging fluid.

[000900] The plunger 3091 and plate 3022 may be formed from or with a surface that slides easily into an infusion tube 3210 of PVC or non-DEHP material. In some embodiments, plunger 3091 and plate 3022 may be formed from nylon. In another embodiment, the plunger 3091 and the plate 3022 may be metal (e.g., aluminum) that is coated with PTFE. In other embodiments, another plastic may be used or other coatings may be applied to a metal plunger 3091 and/or plate 3022 that provide a low coefficient of friction with a PVC or non-DEHP infusion tube 3210.

[000901] Cam shaft 3080 (Figure 276) and cam follower shaft 3120 (Figure 276) are mounted on stops 3005C, 3005D, 3010C in the lower and upper housing 3005, 3010 as shown in Figures 278. The accuracy of the Movements of the valves 3101, 3111 and the plunger 3091 as well as the use life of the roller elements 3092, 3102, 3112 and the cams 3082, 3083, 3084 are improved through better parallel alignment and correct separation of the two rods 3080, 3120 ( Figure 276). The parallel alignment and separation of the two rods 3080, 3120 (Figure 276) is controlled in part by the parallel alignment and separation of the interruptions 3005C, 3005D, 3010C. In some embodiments, the two housing parts 3005, 3010 are initially formed without interruptions 3005C, 3005D, 3010C. The two parts of the housing 3005, 3010 are then mechanically united as shown in the progression from Figure 279 to Figure 280. The holes 3006, 3007 can then be drilled or drilled by the same machine in the same setting at the same time. The two housing parts 3005, 3010 are shown in Figure 281 after the two holes 3006, 3007 have been created by such a process. In some embodiments, the two housing parts 3005, 3010 include that retain them in a fixed alignment with each other when installed. In an exemplary embodiment, alignment features of the housing parts 3005, 3010 are pressed pins in one of the housing parts 3005, 3010 and corresponding holes in the other. In another example, features in one part extend along separation line 3008 to engage features in the other part. The operation of precisely drilling holes is sometimes line drilling. Line drilling can improve parallel alignment of 3005C, 3005D, 3010C interruptions. Line drilling of interruptions 3005C, 3005D, 3010C into the joined housing parts 3005, 3010 economically creates interruptions 3005C, 3005D, 3010C that combine to form more precisely circular holes 3006, 3007 that are more parallel to each other.

[000902] Pumped volume measurement is based on the measured position of the plunger 3091. In an embodiment as shown in Figure 282, the position of the plunger 3091 is measured remotely without contacting the L-shaped cam follower 3090 of the plunger. In some embodiments, the position of the plunger 3091 is measured with a linear Hall effect encoder IC 6001 (and/or 6002) and a single two-pole magnet 3196 (or 3197). The linear encoder 6001 (Figure 282) is located on the main PCB 3002 (shown in Figure 282 as transparent) and reports the position of the magnet 3196 located on the L-shaped cam follower 3090 of the plunger to the controller. The IC 6001 linear encoder is advantageously mechanically disconnected from moving components, so that the sensor does not wear out, degrade or break with use. In some embodiments, the linear encoder IC 6001 may be AS5410 in part manufactured by Austriamicrosystems of Austria. The AS5410 allows the conversion of a wide range of geometries including curved motion, non-linear scaling and tilted chip/magnet geometries to a linear output signal. The flexibility of the linear encoder IC 6001 allows for greater tolerances in the placement of the main PCB 3002 relative to the plunger magnet 3196. Alternatively, the position of the plunger 3091 can be measured with a vision system that utilizes edges or datum located on the cam follower. L-shape 3090 of the plunger. Alternatively, the position of plunger 3091 may be measured with any of a number of other sensors well known in the art, including one or more of the following: a linear potentiometer, a rotary potentiometer, rotary encoder, linear encoder, or LVDT. Methods for mechanically connecting one of these sensors to the plunger L-shaped cam follower 3090 may be those apparent to a person skilled in the art. Additionally or alternatively, the linear encoder 6002 can be used to measure the position of the plunger 3091 with the use of the magnet 3197. The results of the two linear encoders 6001, 6002 can be used by averaging their results together and/or one can be a backup copy for the other, in some specific modalities. For example, the redundancy of the two linear encoders 6001, 6002 may allow operation in a fault operating mode in the event that one of the two linear encoders 6001, 6002 fails or is otherwise compromised. This redundancy can also be used to cross check results from one of the two linear encoders 6001, 6002 with the other of the two linear encoders 6001, 6002 to ensure that both linear encoders 6001, 6002 are functioning properly. Upon identification of an inoperative encoder, one of the two linear encoders 6001, 6002, the RTP 3500 (see Figure 324), may disregard the inoperative encoder. The two linear encoders 6001, 6002 can be compared to the motor hall sensors 5043 and/or the rotary position sensor 5042 to determine the inoperative (reference to Figure 346).

[000903] The slide occluder 3200 can be seen in Figure 261. The slide occluder 3200 serves to clamp the infusion tube 3210 closed, blocking the flow, when the infusion tube 3210 is in the narrow part of the opening 3200D. Flow is permitted through the infusion tube 3210 when it is located at the wide end of the opening 3200C on the front of the slide occluder 3200. The open position on the slide occluder 3200 refers to the infusion tube 3210 which is located at the end 3200C wide aperture. The closed position of the slide occluder 3200 refers to the infusion tube 3210 which is located in the narrow part of the opening 3200D. The slide occluder 3200 includes at least one opening 3200A at the front end of the slide occluder 3200 in a raised wall 3200E that extends along the perimeter of the slide occluder 3200. A flap 3200B is located at the rear end of the slide occluder 3200 .

[000904] The process of closing the door 3020 and inserting the slide carrier 3041 to release the slide occluder 3200 is described with reference to Figures 283 to 293. Figure 283 illustrates the slide occluder 3200 completely inserted into the door split carrier 3040 and the infusion tube 3210 secured in the clamps 3062A, 3024 (Figure 257). Door installation 3021 can close by rotating around hinges 3010A. The initial position of the split-body conveyor 3045 in the pump body 3001 can be seen in Figure 284. The slot 3045E in the split-body conveyor 3045 receives the slide occluder 3200 when the port installation 3021 is closed against the pump body 3001 The opening 3045B in the split body conveyor 3045 accommodates the flap 3200B of the slide occluder 3200 allowing the rear end of the slide occluder 3200 to enter the split body conveyor 3045 and allowing the door installation 3021 to close. Broken body conveyor 3045 and/or upper housing 3010 may prevent door installation 3021 from closing when slide occluder 3200 has been incorrectly oriented. The side of the split body carrier 3045 opposite the opening 3045B does not provide an opening or slot that can accommodate the flap 3200B in the slide occluder 3200. In some embodiments, the upper housing 3010 includes a rail 3010E (Figure 287) that blocks the flap. 3200B.

[000905] Figure 285 illustrates an example two-part split conveyor installation 3041 in the open position. Such a position can be reached when the door installation 3021 is open. Figure 286 illustrates the installation of two-part conveyor 3041 in the closed position. Such a position can be achieved when the door installation 3021 is closed against the pump body 3001. The geometric axis of the linkage 3040B is approximately aligned with the geometric axis of the linkage 3010A of the upper housing 3010 when the door installation 3021 is open. A hinge pin 30410 extending along the axis of the hinge 3040B may be included to hingely couple the body split carrier 3045 and the door split carrier 3040 together. The two-part split conveyor installation 3041 (a conveyor) includes a first portion 3045 (e.g., a body split conveyor 3045), a second portion 3040 (a door split conveyor 3040). The door split conveyor 3040 includes at least one slot 3040D that allows it to accommodate at least one tab 3020D in the door 3020 and the rail 3010E (Figure 287) in the upper housing 3010. In an alternative embodiment shown in Figures 262 to 263, the slot 3040D can accommodate or be guided in the tabs 3020D, 3020F (as is easily seen in Figure 285). The split body carrier 3045 includes at least one slot 3045D to accommodate the rail 3010E (Figure 287) in the upper housing 3010 and/or the rail 3015E (Figure 256A) in the sensor housing 3015. The slots 3040D and 3045D allow the carrier 3041 slide inside the pump body 3001 and the door 3020 when the door 3020 is closed against the body 3001.

[000906] Figure 287 illustrates part of the pump body 3001 with the door 3020 partially closed and some elements removed to reveal the slide occluder 3200 in the closed broken conveyor 3041. The door installation 3021 is closed and the lever 3025 has not started to engage the body pins 3011. The position of the split conveyor 3041 comprising parts 3045 and 3040 is controlled by the position of the lever 3025. The split conveyor 3041 is impelled towards the pump body 3001 by a rib 3025F as the lever 3025 is closed or rotated toward pump casing 3001. Broken carrier 3041 is pulled partially out of pump casing 3001 by lever linkage 3035 (best seen in Figures 290 to 293) as lever 3025 is opened or rotated in the reverse direction of the pump casing 3001. The port split conveyor 3040 is connected to the lever 3025 by means of the closed end of the lever link 3035C (Figure 264) which fits over the conveyor pin 3040A and the open end 3035B (Figure 264) retains a pin 3026 that slides in a slotted rib 3025A (Figure 264) in the lever 3025. The travel of the broken carrier 3041 may be limited to accommodate the slide occluder openings 3200C, 3200D (as best seen in Figure 261). . In such embodiments, the limited travel of the slide conveyor 3041 may not create an optimal amount of mechanical advantage during rotation of the lever 3025 to allow the lever 3025 to engage the body pins 3011 and compress the infusion tube 3210 against the valves. inlet and/or outlet 3101, 3111. One solution is to allow the lever 3025 to rotate through some portion of its full motion without moving the split conveyor 3041. In one embodiment, the lever 3025 may be rotatably mounted to the installation of door 3021. Upon closing of the door installation 3021, the door installation 3021 contacts the split conveyor 3041 to push the split conveyor 3041 into a recess included in the pump body 3001. The gate installation 3021 can be connected to the party transporter 3041 by a member. The member may be configured to remove the broken carrier 3041 from the recess when the lever 3025 is open. Upon opening the lever 3025, at least a portion of the connecting member may be caused to move a predetermined amount or distance before the connecting member removes the broken carrier 3041 from the recess. In this embodiment, the connecting member can have several forms that are discussed in detail in the following paragraphs. In Figure 287, the connecting member is a link 3035 that is mounted on a column of the gated conveyor 3040 and is connected to the lever 3025 through a slot 3025A. In Figure 288, the connecting member comprises two hinged connections 3036, 3037, which connect to the column 3040A on the door split conveyor 3040 and are pivotably pinned to the lever 3025 at 3025G. Alternatively, the two hinged connections 3036, 3037 could be replaced with a flexible cable or stretch member that attaches to the door split conveyor or lever 3025.

[000907] The lever 3025, the split conveyor 3041 and the port installation 3021 are designed to maintain occlusion of the infusion tube 3210 at all times during the opening and closing processes of the door 3020. The infusion tube 3210 is occluded pressing the door 3020 against the body 3001, before the slide occluder 3200 is moved by the broken conveyor 3041 during closing. In the opening process, the slide occluder 3200 is first moved to occlude the infusion tube 3210 before the port 3020 is disengaged from the body 3001, thereby maintaining the occlusion of the infusion tube 3210 as mentioned above.

[000908] Referring now specifically to Figure 287, the slotted rib 3025A and the lever linkage 3035 allow the lever 3025 to rotate several degrees and begin to engage the body pins 3011 with the latch hooks 3025C without moving the broken carrier. 3041 during closing of the lever 3025. Upon opening, the slotted rib 3025A and lever linkage 3035 allow the lever 3025 to retract the broken carrier 3041 and occlude the infusion tube 3201 before disengaging the body pins 3011 and releasing the infusion tube 3210 from valves 3101, 3111. The lever link 3035 can mechanically connect the lever 3025 to the door split conveyor 3041 so that the lever 3025 only applies a tension force to the lever link 3035. Limit the force on the link 3035 lever linkage to tension strength removes the need to ensure the 3035 lever linkage is resistant to buckling, allowing the 3035 lever linkage to be lighter and smaller.

[000909] Rotation of the lever 3025 in the direction of the port 3020 and the body 3001 compresses the infusion tube 3210 between the plate 3022 and the valves 3101, 3111 and the plunger 3091, locks the port 3020 and moves the slide occluder 3200 to an open position. The lever connection 3035, the split rib 3025A and the latch hook geometry 3025C ensure that the infusion tube 3210 is occluded by at least one of the valves 3101, 3111 before the slide occluder 3200 is moved to the open position when lever 3025 is closed. The lever connection 3035, the split rib 3025A and the latch hook geometry 3025C also ensure that the slide occluder 3200 is moved to the occluding position before the infusion tube 3210 is occluded by valves 3101, 3111 when the lever 3025 is open. This sequence of occluding flow through the infusion tube 3210 with one element before releasing the second element ensures that the infusion tube 3210 is never in a free-flowing state during loading of the infusion tube 3210 into the peristaltic pump 2990.

[000910] Alternatively, the gated conveyor 3040 can be pulled out of the pump body 3001 by the lever 3025 which is connected to the gated conveyor 3040 by two links 3036, 3037 as shown in Figure 288. The first link 3036 is fits over broken carrier pin 3040A and connects to second link 3037 on linkage 3036A. The second link connects the first link 3036 to the lever 3025 at a pivot point 3025G. The two bonds 3036, 3037 each have a flat surface 3036B, 3037B that limits the relative rotation of the bonds 3036, 3037 so that they never cross a center point and always bend toward each other in the same direction. In the depicted embodiment, the links 3036, 3037 may bend only so that their mutual pivot point 3036A moves in the direction of retreat from the lever pivot 3025B as the lever 3025 closes. The two connections 3036, 3037 allow the lever 3025 to rotate several degrees and begin to engage the body pins 3011 with the latch hooks 3025C and occlude the infusion tube 3210 against at least one of the valves 3101, 3111 without moving the broken carrier 3041. Once two links 3036, 3037 have bent and closed, the rib 3025F comes into contact with the gate split conveyor 3040. The rib 3025F impels the split conveyor 3041 into the pump body 3001 as the lever 3025 completes its rotation in the direction of installing port 3021.

[000911] Upon opening the lever 3025 or rotating the lever 3025 in the direction of retreat of the door installation 3021, the two links 3036, 3037 unfold and only begin to retract the broken conveyor 3041 after an initial amount of rotation of the lever 3025 During the second part of the rotation of the lever 3025, the broken carrier 3041 withdraws from the pump body 3001 and moves the slide occluder 3200, which occludes the infusion tube 3210 before disengaging the body pins 3011 and releasing the delivery line. infusion 3210 from valves 3101, 3111. Infusion tube 3210 is occluded by valves 3101, 3111, but is occluded by slide occluder 3200 during the third portion of rotation of lever 3025.

[000912] Alternatively, the two connections 3036, 3037 could be reattached with a flexible cable or wire, which pulls the broken conveyor 3041 away from the pump body 3001. The flexible cable can be attached to the broken door conveyor 3040 and to a fixed point on lever 3025. Broken conveyor 3041 is impelled toward pump casing 3001 by rib 3025F as lever 3025 rotates toward pump casing 3001.

[000913] In Figure 293, door 3020 is closed and lever 3025 is locked accordingly. The broken conveyor 3041 was slid through the port 3020 and into the body 3001. Movement of the broken conveyor 3041 moves the slide occluder 3200 into the pump body 3001, while the infusion tube 3210 is held in position. Movement of the slide occluder 3200 relative to the infusion line 3210 moves the infusion tube 3210 to the wide end 3200C of the slide occluder 3200 allowing flow through the infusion tube 3210.

[000914] Figures 290 to 293 illustrate four steps of closing the port 3020. In Figure 290, the port installation 3021 is open and the infusion tube 3210 and the slide occluder 3200 are installed. In Figure 291, the port installation 3021 is closed, the lever 3025 is open, and the split conveyor 3041 is completely retracted, then the infusion tube 3210 is occluded by the slide occluder 3200. In Figure 292, the lever 3025 is partially rotated towards the body 3001 to a point where the broken carrier 3041 has not moved and the slide occluder 3200 still occludes the infusion tube 3210, but the latch hooks 3025C have engaged the body pins 3011 and also occluded the infusion tube 3210 between the port installation 3021 and at least one of the valves 3101, 3111. In Figure 293, the lever 3025 is completely rotated toward the pump body 3001 or closed. In Figure 293, the slide carrier 3041 is completely inserted into the pump body 3001 such that the infusion tube 3210 is no longer occluded by the slide occluder 3200 and the port 3021 is completely preloaded against the pump body 3001 which includes at least one of the valves 3101, 3111 is still occluding the infusion tube 3210 as shown in Figure 292. In some embodiments, actuation of the lever handle 3025 to hook the port installation 3021 to the pump body 3001 may also actuate the valve valve 3101 or outlet valve 3111 (see Figure 274) to occlude infusion tubing 3210 (e.g., by pushing port installation 3021 closer to the pump body and/or controlling by RTP 3500 (see Figure 324) the motor 3072 (see Figure 324) to rotate the camshaft 3080 (see Figure 266) so that one or both the inlet valve 3101 and the outlet valve 3111 are occluding the infusion tube 3210).

[000915] Figures 294 to 298 illustrate elements of the door installation 3021, the pump body 3001 and the lever 3025 that lock together the door 3020 and position the door installation 3021 parallel to the face of the upper housing 3010 and occlude the tube of infusion 3210 between the plate 3022 and at least one of the valves 3101, 3111 and/or the plunger 3091. The port installation 3021 is positioned and pressed against the upper housing 3010 without placing a load on the pivot pin 3012 or requiring close tolerance in pivot pin 3012 and pivot holes 3020J, 3010F (Figure 258).

[000916] As described above and depicted in Figure 287, the two latch hooks 3025C engage the body pins 3011, which are mounted on the tabs 3010B of the upper housing 3010, when the door installation 3021 has been rotated to contact the upper housing 3010 and lever 3025 is rotated toward door 3020. Latch hooks 3025C have tapered openings to ensure engagement for a wider range of home positions between door installation 3021 (Figure 257) and upper housing 3010 (Figure 258). The opening in latch hook 3025C is shaped to bring latch pin 3034 (Figure 295) closer to body pin 3011 as lever 3025 (Figure 296) is rotated. The latch pin 3034 (Figure 295) is free to move into the door 3020 along the slots 3020C as the latch pin 3034 moves toward the body pin 3011 (Figure 294). The slot structure 3020C at the top of the door 3020 in Figure 294 is repeated toward the bottom of the door 3020 in Figure 295, where the second latch 3025C engages the pin (e.g., a latch pin 3034).

[000917] In Figure 298, movement of the latch pin 3034 toward the upper housing 3010 deflects the door spring 3032 that is supported by the door 3020 at each end 3032a of the door spring 3032. Deflection of the door spring 3032 generates a force that is applied to the port 3020 and directed to the upper housing 3010 and the pump body 3001. As shown in Figure 296, the port 3020 may include protrusions or offsets 3020H that contact the face of the upper housing 3010 in three or more places distributed around valves 3101, 3111 and plunger 3091 (Figure 260). In some embodiments, the offsets 3020H are configured so that the spring force is equally distributed to each offset 3020H. In some embodiments, as shown, for example, in Figure 296, four offsets 3020H are located around the plate 3022, near where the valves 3101, 3111 (Figure 260) contact the infusion tube 3210. The pivot pin 3020J in door 3020 are slightly oversized for pivot pin 3012 (Figure 295), which allows door 3020 to rest on offsets 3025H without being restricted by pivot pin 3012.

[000918] Figure 297 shows a cross-section through latch pin 3034 and includes latches 3025C fully engaging body pins 3011. In some embodiments, body pins 3011 include a plain bearing 3011A to reduce wear and friction. Plain bearing 3011A can be hard material tube that can rotate on body pin 3011 to reduce wear on latch hooks 3025C. Latch pin 3034 passes through lever pivot holes 3025B and is free to move in slots 3020C and deflect port spring 3032. In Figure 297, plunger 3091 is in a position to compress infusion tube 3210 against the plate. 3022. The force of the deflected port spring 3032 supplies the force to compress the infusion tube 3210 from the plate side 3022, while the plunger operating member 3094 (Figure 267) supplies the force on the plunger side 3091.

[000919] Figure 298 shows a cross-section along the midline of door spring 3032 and perpendicular to latch pin 3034. Deflection of door spring 3032 is evident between latch pin 3034 and an edge 3020F at each end of door spring 3032 and spring stop 3020G. Figure 296 shows an embodiment in which the offsets 3020H are located between and equally distant at the locations where the door spring 3032 contacts the door 3020.

[000920] As shown in the embodiment in Figures 299 to 300, one of the latch hooks 3025C may comprise detents 3025G, 3025J and a spring pin 3027 or ball for engaging the detents 3025G, 3025J. Figures 299 illustrates the lever 3025 completely closed against the door 3020. The latch hook 3025C includes a first detent 3025G that is engaged by a spring pin 3027. The spring pin 3027 is mounted on the door 3020 in such a position that it engages the first detent 3025G when lever 3025 is closed.

[000921] Figure 300 illustrates the lever 3025 completely opened in relation to the door 3020 and the door split conveyor 3040 retracted. Spring pin 3027 engages a second detent 3025J when door 3020 is in the fully open position. In some embodiments, detents 3025G, 3025J on latch hooks 3025C may allow lever 3025 to retain one or more positions relative to door 3020.

[000922] Figure 301 illustrates a detection lever 3150 displaced by the slide occluder 3200, when the port installation 3021 and the lever 3025 (Figure 265) are completely closed. The detection lever 3150 rotates on a pin 3151 that is secured to the upper housing 3010 and swings through a slot 3045F in the body split carrier 3045. If a slide occluder 3200 is present in the split carrier 3041 when the door 3020 is closed, The slide occluder 3200 will deflect the sensing lever 3150 upward toward the main PCB 3002. A sensor 3152 on the main PCB 3002 will detect the proximity of a magnet 3150A on the sensing lever 3150. The sensing lever 3150, the magnet 3150A and sensor 3152 may be designed to detect only a specific geometry of slide occluder 3200. Other slide occluders 3200 or slide occluder shapes 3200 may not deflect detection lever 3150 enough for sensor 3152 to detect magnet 3150A or cause the sensing lever 3150 to contact the main PCB 3002 and prevent complete insertion of the broken carrier 3041 and closing of the lever 3025. A controller may only allow operation when the sensor 3152 detects the sensing lever 3150 displaced, which indicates that the appropriate slide occluder 3200 is present.

[000923] Figure 302 illustrates a latch hook detection slide 3160 displaced by the latch hook 3025C, when the door installation 3021 and the lever 3025 are completely closed. The latch hook detection slide 3160 may include one or more slots 3160A that guide it by screws or posts mounted in the upper housing 3010. A spring 3164 returns the latch hook detection slide 3160 to a non-displaced position when the latch hook 3025C is not engaging the body pin 3011. The latch hook detection slide 3160 may include at least one magnet 3161 that is located so that a sensor 3163 mounted on the main PCB 3001 can detect its presence only when the detection slide 3160 is completely moved. In some embodiments, the latch hook detection slide 3160 may include a second at least one magnet 3162 that is detected by the sensor 3163 only when the latch hook detection slide 3160 is completely retracted. A controller may only allow operation when the sensor 3163 detects the latch hook detection slide 3160 displaced, which indicates that the lever 3025 is completely closed.

[000924] Figures 303 to 310 show various views relating to a system 3200. Figure 303 shows a system 3200 that includes several pumps 3201, 3202, and 3203. The pumps 3208. The system 3200 includes two syringe pumps 3201, 3202 and a 3203 peristaltic pump; however, other combinations of various medical devices may be employed.

[000925] Each of the pumps 3201, 3202, 3203 includes a touch screen 3204 that can be used to control the pumps 3201, 3202, 3203. One of the pumps' touch screens 3204 (e.g., 3201, 3202, 3203) can also be used to coordinate the operation of all pumps 3201, 3202, 3203 and/or to control one or more of the other pumps 3201, 3202, 3203.

[000926] Pumps 3201, 3202 and 3203 are daisy-chained together so that they are in electrical communication with each other. Additionally or alternatively, pumps 3201, 3202, and/or 3203 may share power with each other or with each other. For example, one of the pumps 3201, 3202 and/or 3203 may include an AC/DC converter that converts AC electrical power to suitable DC power to power the other pumps 3201, 3202, 3203.

[000927] Within system 3200, pumps 3201, 3202 and 3203 are stacked together using Z-frames 3207. Each of the Z-frames 3207 includes a lower portion 3206 and an upper portion 3205. A lower portion 3206 of a Z-frame 3207 (e.g., the lower portion 3206 of pump 3201) may engage an upper portion 3205 of another Z-frame 3207 (e.g., the upper portion 3205 of Z-frame 3207 of pump 3202).

[000928] A claw 3209 can be coupled to one of the pumps 3201, 3202, 3203 (e.g., the pump 3202 as shown in Figure 304). In other words, the claw 3209 can be attached to any of the pumps 3201, 3202 and/or 3203. The claw 3209 is attachable to the back of any of the pumps 3201, 3202, and/or 3203. As is easily seen in Figure 306, each of the pumps 3201, 3202, 3203 includes an upper clamping member 3210 and a lower clamping member 3211. A claw adapter 3212 facilitates attachment of the claw 3209 to the pump 3202 by means of an upper clamping member 3210 and a lower securing member 3211 respective of a pump (e.g., 3201, 3202, or 3203). In some embodiments, the claw adapter 3212 may be integral with the claw 3209.

[000929] Figure 307 shows a close-up view of a portion of a clamp interface (i.e., clamp adapter 3212) that is attachable to pump 3202 (or pumps 3201 or 3203) shown in Figures 304-306 of according to an embodiment of the present description. The gripper adapter 3212 includes a hole 3213 into which a lower clamping member 3211 (see Figure 306) can be attached. That is, the lower fixing member 3211, a hook-like curved protrusion, can be inserted into the hole 3213 and then rotated to secure the lower fixing member 3211 therein.

[000930] As can be easily seen in Figure 308, the claw adapter 3212 also includes a latch 3214. The latch 3214 is pivotally mounted to the claw adapter 3212 by means of pivots 3216. The latch 3214 can be oriented by means of springs 3218 which are coupled to hooks 3220. Stopping members 3219 prevent pivoting of latch 3214 beyond a predetermined amount. After the hole 3213 is positioned in the lower fixing member 3211, the claw adapter 3212 can be rotated to bring the latch 3214 toward the upper fixing member 3210 so that the latch 3214 is compressed downward by the upper fixing member 3210 until the protrusion 3215 fits into a space complementary to the upper fastening member 3210. The hooks 3220 help secure the claw adapter 3212 to the pump 3202.

[000931] Each of these Z-frames 3207 for each of the pumps 3201, 3202, 3203 includes a re-entry portion 3223 in its upper portion 3205 (see Figure 306) and each pump 3201, 3202, 3203 includes a protrusion 3224 (see Figure 309). A protrusion 3224 of one of the pumps (e.g., pumps 3201, 3202, or 3203) may engage a re-entry portion 3223 of another Z-frame to enable the pumps 3201, 3202, 3203 to be stacked on top of each other. Each of the pumps 3201, 3202, 3203 includes a latch engagement member 3221 that allows another of the pumps 3201, 3202, 3203 to be secured thereto by means of a latch 3222 (see Figure 309). The latch 3222 may include a small spring-loaded flange that may "snap" into the space formed beneath the latch engagement member 3221. The latch 3222 may be pivotally coupled to the lower portion 3206 of the Z-frame 3207.

[000932] As seen in Figure 304, the latch 3222 of the Z-frame of the pump 3201 can be pulled to remove a portion of the latch 3222 out of the space under the latch engagement member 3221 of the pump 3202. Thereafter, the pump 3201 can be rotated to pull the protrusion 3224 of the pump 3201 out of the re-entry portion 3223 of the Z-frame of the pump 3202 so that the pump 3201 can be removed from the pump stack 3202, 3203 (see Figure 305).

[000933] Each of pumps 3201, 3202, 3203 includes a top connector 3225 (see Figure 310) and a bottom connector 3226 (see Figure 309). Connectors 3225 and 3226 allow stacked pumps 3201, 3202 and 3203 to communicate with each other and/or provide power to each other. For example, if the battery of the middle pump 3202 (see Figure 303) fails, then the top pump 3201 and/or the bottom pump 3203 can provide power to the middle pump 3202 as a backup while one or more of the pumps 3201, 3202, 3203 are emitting an audible alarm.

[000934] An exemplary embodiment of the graphical user interface (hereinafter GUI) 3300 is shown in Figure 311. The GUI 3300 enables a user to modify the way in which an agent can be introduced by customizing various programming options. For the purpose of illustration, the GUI 3300 detailed as follows utilizes a screen 3204 which is a touch screen as a means for interacting with a user. In other embodiments, the means of interacting with a user may be different. For example, alternative embodiments may comprise user pressable buttons or rotary dials, audible commands, etc. In other embodiments, screen 3204 may be any electronic visual display such as a liquid crystal display, L.E.D. display, plasma display.

[000935] As detailed in the preceding paragraph, GUI 3300 is displayed on the screen of pumps 3203. All pumps 3201, 3202, 3203 may have their own individual screen 3204 as shown in Figures 303 to 305. In arrangements where one of the pumps 3201, 3202, 3203 is being used to control all pumps 3201, 3202, 3203, only the main pump may require a screen 3204. As shown, the pump is resting on a Z-frame 3207. As shown, the GUI 3300 may display numerous 3250 interface fields. The 3250 interface fields can display various information about the pump or infusion status, medication, etc. In some embodiments, interface fields 3250 in GUI 3300 may be tapped, tapped, etc. to navigate different menus, expand a 3250 interface field, enter data, and the like. The 3250 interface fields displayed in the 3300 GUI may change from menu to menu.

[000936] The GUI 3300 can also have numerous virtual buttons. In the non-limiting exemplary embodiment in Figure 311, the display has a virtual power button 3260, a virtual start button 3262, and a virtual stop button 3264. The virtual power button 3260 can turn on or off the pump 3201, 3202, 3203 The virtual start button 3262 can start an infusion. The virtual stop button 3264 can pause or stop an infusion. Virtual buttons can be activated by a user's touch, tap, double tap or similar. Different GUI 3300 menus may comprise other virtual buttons. Virtual buttons can be skeuomorphic to make their functions more immediately understandable or recognizable. For example, the virtual stop button 3264 may resemble a stop sign as shown in Figure 305. In alternative embodiments, the names, formats, functions, number, etc. of the virtual buttons may differ.

[000937] As shown in the exemplary embodiment in Figure 312, the interface fields 3250 of the GUI 3300 (see Figure 311) can display a number of different programming parameter input fields. For the 3300 GUI to display parameter input fields, a user may be required to navigate through one or numerous menus. Additionally, the user may be required to enter a password before the user can manipulate any of the parameter input fields.

[000938] In Figure 312, a medication parameter input field 3302, drug quantity in container parameter input field 3304, total volume in container parameter input field 3306, concentration parameter input field 3308 , dose parameter input field 3310, volume flow rate (hereinafter abbreviated as rate) parameter input field 3312, volume to be input (hereinafter VTBI) parameter input field 3314 and time 3316 are displayed. The parameters, number of parameters, parameter names, etc. may differ in alternative modalities. In the exemplary embodiment, the parameter input fields are graphically displayed boxes that are substantially rectangular with rounded corners. In other embodiments, the format and size of the parameter input fields may differ.

[000939] In the exemplary embodiment, the GUI 3300 is designed to be intuitive and flexible. A user can choose to fill in a combination of parameter input fields that are the simplest or most convenient for the user. In some embodiments, parameter input fields left empty by the user may be automatically calculated and displayed by the GUI 3300 as long as the empty fields do not operate independently of populated parameter input fields and sufficient information can be gleaned from the populated fields to calculate the field or empty fields. Throughout Figures 312 to 316, the fields dependent on each other are joined by curved double-headed arrows.

[000940] Medication parameter input field 3302 may be the parameter input field in which a user adjusts the type of infusion agent to be input. In the exemplary embodiment, the medication parameter input field 3302 was filled in and the infusion substance was defined as "0.9% NORMAL PHYSIOLOGICAL SERUM". As shown, after the specific infusion substance has been adjusted, the GUI 3300 can populate the medication parameter input field 3302 by displaying the name of the specific infusion substance in the medication parameter input field 3302.

[000941] To adjust the specific infusion agent to be introduced, a user can tap the medication parameter input field 3302 on the GUI 3300. In some embodiments, it can select a list of possible infusion substances. The user can search through the list until the desired infusion substance is located. In other embodiments, touching the medication parameter input field 3302 may select a virtual keyboard. The user can then type the infusion substance on the virtual keyboard. In some embodiments, the user may need to type only a few letters of the infusion substance on the virtual keyboard before the GUI 3300 displays numerous suggestions. For example, after typing "NORE" the 3300 GUI may suggest "NOREPINEPHRINE". After locating the correct infusion substance, the user may be required to perform an action such as, but not limited to, tapping, double tapping, or touching or dragging the infusion substance. After the required action has been completed by the user, the infusion substance may be displayed by the GUI 3300 in the medication parameter input field 3302. For another detailed description of another exemplary means of infusion substance selection see Figure 322.

[000942] In the exemplary embodiment in Figure 312, parameter input fields were arranged by a user to perform an infusion based on volume (e.g., ml, ml/hour, etc.). Consequently, the drug quantity in container parameter input field 3304 and the total volume in container parameter input field 3306 were left unpopulated. The concentration parameter input field 3308 and the dose parameter input field 3310 were also left unpopulated. In some embodiments, the drug quantity in container parameter input field 3304, the total volume in container parameter input field 3306, the concentration parameter input field 3308, and the dose parameter input field 3310 may be blocked, dimmed, or not displayed in the 3300 GUI when such an infusion has been selected. The drug quantity in container parameter input field 3304, the total volume in container parameter input field 3306, the concentration parameter input field 3308 and the dose parameter input field 3310 will be further elaborated in the subsequent paragraphs.

[000943] When the GUI 3300 is being used to program a volume-based infusion, the rate parameter input field 3312, the VTBI parameter input field 3314, and the time parameter input field 3316 do not operate independently of each other. A user may be required to only define any two fields of the rate parameter input field 3312, the VTBI parameter input field 3314 and the time parameter input field 3316. The two parameters defined by a user may be be the most convenient parameters for a user to adjust. The parameter left empty by the user can be automatically calculated and displayed by the GUI 3300. For example, if a user fills the rate parameter input field 3312 with a value of 125 ml/hour (as shown) and fills the input field of VTBI 3314 parameter with a value of 1000 ml (as shown) the time parameter input field 3316 value can be calculated by dividing the value in the VTBI 3314 parameter input field by the value in the parameter input field rate 3312. In the exemplary embodiment shown in Figure 312, the quotient from the above calculation, 8 hours and 0 minutes, is correctly filled in by the GUI 3300 in the time parameter input field 3316.

[000944] For a user to fill in the rate parameter input field 3312, the VTBI parameter input field 3314 and the time parameter input field 3316, the user can tap or tap the parameter input field desired in GUI 3300. In some embodiments, this may select the numeric keypad with a range or number, such as 0 to 9 displayed as individual selectable virtual buttons. A user may be required to enter the parameter by tapping, tapping twice, tapping and dragging individually, etc. the desired numbers. Once the desired value has been entered by a user, a user may be required to tap, tap twice, etc. a virtual "confirm", "enter", etc. button. to fill in the field. For another detailed description of another exemplary way of defining numerical values see Figure 322.

[000945] Figure 313 shows a situation in which the infusion parameters that are programmed are not those of a volume-based infusion. In Figure 313, the infusion profile is that of a continuous volume/time dose rate. In the exemplary embodiment shown in Figure 313, all parameter input fields have been filled. As shown, the 3302 medication parameter input field in the 3300 GUI has been populated with "HEPARIN" as the defined infusion substance. As shown, the drug quantity in container parameter input field 3304, the total volume in container input field 3306, and the concentration parameter input field 3308 are populated in Figure 313. Additionally, since an infusion of volume/time is being programmed, the dose parameter input field 3310 shown in Figure 312 has been replaced with a dose rate parameter input field 3318.

[000946] The drug quantity parameter input field in container 3304 is a two-part field in the exemplary embodiment shown in Figure 313. In the exemplary embodiment in Figure 313, the left field of the drug quantity parameter input field in container 3304 is a field that can be filled with a numeric value. The numeric value can be defined by the user in the same way that a user can define the values in the rate parameter input field 3312, the VTBI parameter input field 3314, and the time parameter input field 3316. In embodiment In the example shown in Figure 313, the numerical value displayed by GUI 3300 in the left field of the drug quantity parameter input field in container 3304 is "25,000".

[000947] The parameter defined by the right field of the drug quantity parameter input field in container 3304 is the unit of measurement. To set the right of the drug quantity parameter input field in container 3304, a user can tap the drug quantity parameter input field in container 3304 on the GUI 3300. In some embodiments, this may select a list of units possible acceptable measurements. In such embodiments, the desired unit of measurement can be defined by a user in the same way that a user can define the correct infusion substance. In other embodiments, touching the drug quantity parameter input field in container 3304 may select a virtual keyboard. The user can then type the correct unit of measurement on the virtual keyboard. In some embodiments, the user may be required to tap, tap twice, etc. a virtual "confirm", "enter" button to fill the left field of the drug quantity parameter input field in the container 3304.

[000948] In some embodiments, including the embodiment shown in Figure 313, the right field of the drug quantity parameter input field in container 3304 may have one or more acceptable values that may be dependent on the parameter input in one or more other parameter input fields. In the exemplary embodiment, the meaning of the measurement unit "UNITS" may differ depending on the infusion substance set in the medication parameter input field. GUI 3300 may also automatically convert the value and unit of measurement, respectively, in the left field and right field of the drug quantity parameter input field in container 3304 to an equivalent measurement if a user enters a unit of measurement. non-metric measurement in the right field of the drug quantity parameter input field in container 3304.

[000949] The total volume in the container parameter input field 3306 can be populated by a numeric value that defines the total volume of a container. In some embodiments, the GUI 3300 may automatically populate the total volume in the container parameter input field 3306 based on data generated by one or more sensors. In other embodiments, the total volume in the container parameter input field 3306 may be manually entered by a user. The numeric value may be defined by the user in the same manner that a user may define values in the rate parameter input field 3312, the VTBI parameter input field 3314, and the time parameter input field 3316. In exemplary embodiment shown in Figure 313, the total volume in the container parameter input field 3306 has been filled with the value "250" ml. The total volume in the container parameter input field 3306 can be restricted to a unit of measure such as ml as shown.

[000950] The concentration parameter input field 3308 is a two-part field similar to the drug quantity parameter input field in the container 3304. In the exemplary embodiment in Figure 313 the left field of the concentration parameter input field 3308 is a field that can be filled with a numeric value. The numeric value may be defined by the user in the same manner that a user may define values in the rate parameter input field 3312, the VTBI parameter input field 3314, and the time parameter input field 3316. In exemplary embodiment shown in Figure 313, the numerical value displayed by the GUI 3300 in the left field of the concentration parameter input field 3308 is "100".

[000951] The parameter defined by the right field of the concentration parameter input field 3308 is a unit of measure/volume. To set the right field of the concentration parameter input field 3308, a user may touch the concentration parameter input field 3308 in the GUI 3300. In some embodiments, this may select a list of possible acceptable units of measurement. In such embodiments, the desired unit of measurement can be defined by a user in the same way that a user can define the correct infusion substance. In other embodiments, touching the concentration parameter input field 3308 may select a virtual keyboard. The user can then type the correct unit of measurement on the virtual keyboard. In some embodiments the user may be required to tap lightly, tap twice, etc. a virtual "confirm", "enter" button to store the selection and move to a list of acceptable volume measurements. The desired volume measurement can be set by a user in the same way that a user can set the correct infusion substance. In the exemplary embodiment shown in Figure 313, the right field of the concentration parameter input field 3308 is populated with the measurement/volume unit "UNITS/ml".

[000952] The drug quantity parameter input field in the container 3304, the total volume in the container input field 3306 and the concentration parameter input field 3308 are not independent of each other. As such, a user may only be required to define any two fields among the drug quantity in container parameter input field 3304, the total volume in container input field 3306 and the concentration parameter input field 3308. For example, if a user filled in the concentration parameter input field 3308 and the total volume in the container parameter input field 3306, the drug quantity in container parameter input field could be automatically calculated and populated in the GUI 3300.

[000953] Since the GUI 3300 in Figure 313 is being programmed for a continuous volume/time dose, the dose rate parameter input field 3318 has been populated. The user can define the rate at which the infusion substance is introduced by filling in the dose rate parameter input field 3318. In the exemplary embodiment in Figure 313, the dose rate parameter input field 3318 is a field similar to the drug in container quantity parameter input field 3304 and the concentration parameter input field 3308 described above. A numeric value may be set in the left field of the dose rate parameter input field 3318 by the user in the same manner that a user may set values in the rate parameter input field 3312. In the exemplary embodiment in Figure 313, the field left side of dose rate parameter input field 3318 has been filled with the value "1,000".

[000954] The right field of the dose rate parameter input field 3318 can define a unit of measure/time. To set the right field of the dose rate parameter input field 3318, a user may tap the dose rate parameter input field 3318 in the GUI 3300. In some embodiments, this may select a list of possible units of measure. acceptable. In such embodiments, the desired unit of measurement can be defined by a user in the same way that a user can define the correct infusion substance. In other embodiments, touching the dose rate parameter input field 3304 may select a virtual keyboard. The user can then type the correct unit of measurement on the virtual keyboard. In some embodiments, the user may be required to tap, tap twice, etc. a virtual "confirm", "enter" button to store the selection move to a list of acceptable time measurements. The desired time measurement can be set by a user in the same way that a user can set the correct infusion substance. In the exemplary embodiment shown in Figure 313, the right field of the dose rate parameter input field 3318 is populated with the measurement/time unit "UNITS/hour".

[000955] In the exemplary embodiment, the dose rate parameter input field 3318 and the rate parameter input field 3312 are not independent of each other. After a user fills in the dose rate parameter input field 3318 or the rate parameter input field 3312, the parameter input field left empty by the user can be automatically calculated and displayed by the GUI 3300 as long as the concentration parameter input 3308 has been set. In the exemplary embodiment shown in Figure 313, the rate parameter input field 3312 has been populated with an infusion substance flow rate of "10 ml/hour". Dose rate parameter input field 3318 has been populated with "1,000" "UNITS/hour".

[000956] In the exemplary embodiment shown in Figure 313, the VTBI parameter input field 3314 and the time parameter input field 3316 have also been populated. The VTBI parameter input field 3314 and the time parameter input field 3316 may be populated by a user in the same manner as described in relation to Figure 306. When the GUI 3300 is being programmed for a continuous dose rate infusion of volume/time, the VTBI parameter input field 3314 and the time parameter input field 3316 are dependent on each other. A user may need to fill in only one of the VTBI parameter input field 3314 or the time parameter input field 3316. The field left empty by the user can be automatically calculated and displayed in the GUI 3300.

[000957] Figure 314 shows a situation in which the infusion parameters being programmed are those of a dose-amount-based infusion herein referred to as an intermittent infusion. In the exemplary embodiment shown in Figure 314, all parameter input fields have been filled. As shown, the medication parameter input field 3302 in the GUI 3300 has been populated with the antibiotic "VANCOMICIN" as the defined infusion substance.

[000958] As shown, the drug quantity parameter input field in the container 3304, the total volume input field in the container 3306 and the concentration parameter input field 3308 are presented in the same way as in Figure 314. In the exemplary embodiment in Figure 308, the left field of the drug quantity parameter input field in container 3304 was filled with "1". The right field of the drug quantity parameter input field in container 3304 has been filled with "g". Therefore the total amount of Vancomycin in the container was defined as one gram. The total volume in the container parameter input field 3306 has been filled with "250" ml. The left field of the concentration parameter input field 3308 has been filled with "4.0". The right field of the concentration parameter input field has been filled with “mg/ml”.

[000959] As mentioned in connection with other possible types of infusions that a user may be able to program through the GUI 3300, the drug quantity parameter input field in the container 3304, the total volume in the container input field 3306 and the concentration parameter input field 3308 are dependent on each other. As above, this is indicated by the curved double arrows connecting the parameter input field names. By filling in any two of these parameters, the third parameter can be automatically calculated and displayed in the correct parameter entry field in the 3300 GUI.

[000960] In the exemplary embodiment in Figure 314, dose parameter input field 3310 has been filled. As shown, the dose parameter input field 3310 comprises a left and right field. A numeric value may be defined in the right field of dose parameter input field 3310 by the user in the same manner that a user may define values for other parameter input fields that define numeric values. In the exemplary embodiment in Figure 314, the left field of the dose parameter input field 3310 has been filled with the value "1,000".

[000961] The right field of dose parameter input field 3310 can define a mass unit measurement. To set the right field of the dose parameter input field 3310, a user may touch the dose parameter input field 3310 in the GUI 3300. In some embodiments, this may select a list of acceptable possible units of measurement. In such embodiments, the desired unit of measurement can be defined by a user in the same way that a user can define the correct infusion substance. In other embodiments, touching the dose parameter input field 3310 may select a virtual keyboard. The user can then type the correct unit of measurement on the virtual keyboard. In some embodiments, the user may be required to tap, tap twice, slide, etc. a virtual "confirm", "enter", etc. button. to store the selection and move to a list of acceptable mass measurements. The desired mass measurement can be set by a user in the same way that a user can set the correct infusion substance. In the exemplary embodiment shown in Figure 314, the right field of the dose parameter input field 3310 is populated with the measurement unit "mg".

[000962] As shown, the rate parameter input field 3312, the VTBI parameter input field 3314 and the time parameter input field 3316 have been populated. As shown, rate parameter input field 3312 has been populated with "125" ml/hour. The parameter input field of VTBI 3314 has been set to "250" ml. The time parameter input field 3316 has been set to "2" hours "00" minutes.

[000963] The user may not need to individually define each of the dose parameter input field 3310, the rate parameter input field 3312, the VTBI parameter input field 3314, and the VTBI parameter input field 3314. time 3316. As indicated by the curved double arrows, the dose parameter input field 3310 and the VTBI parameter input field 3314 are dependent on each other. Entering one value may allow the other value to be automatically calculated and displayed by the GUI 3300. The rate parameter input field 3312 and the time parameter input field 3316 are also dependent on each other. The user may need to identify only one value and then allow the undefined value to be automatically calculated and displayed in GUI 3300. In some embodiments, the rate parameter input field 3312, the VTBI parameter input field 3314, and the time parameter input field 3316 can be locked in GUI 3300 until the drug quantity in container parameter input field 3304, the total volume in container parameter input field 3306, and the drug in container parameter input field 3306 concentration 3308 have been defined. These fields may be blocked due to the fact that the calculation of the rate parameter input field 3312, the VTBI parameter input field 3314 and the time parameter input field 3316 depends on the values in the parameter input field amount of drug in container 3304, total volume in container parameter input field 3306 and concentration parameter input field 3308.

[000964] In situations where an infusion substance may require dosing based on body weight, a weight parameter input field 3320 may also be displayed on GUI 3300. The exemplary GUI 3300 shown in Figure 315 has been arranged so that a user can program a dosage based on body weight. Parameter input fields can be defined by a user as detailed in the discussion above. In the exemplary embodiment, the infusion substance in medication parameter input field 3302 was set to "DOPAMINE". The left field of the drug quantity parameter input field in container 3304 was set to "400". The right field of the drug quantity parameter input field in container 3304 was set to "mg". The total volume in the container parameter input field 3306 has been set to "250" ml. The left field of the concentration parameter input field 3308 was set to "1.6". The right field of the concentration parameter input field 3308 was set to "mg/ml". Weight parameter input field 3320 has been set to "90" kg. The left field of the 3318 dose evaluator parameter input field has been set to "5.0". The right field of the 3318 dose rate parameter input field was set to "mcg/kg/minute". Rate parameter input field 3312 was set to "16.9" ml/hour. The parameter input field of VTBI 3314 has been set to "250" ml. Time parameter input field 3316 was set to "14" hours "48" minutes.

[000965] To set the weight parameter input field 3320, a user may tap or tap the weight parameter input field 3320 in the GUI 3300. In some embodiments, this may select a numeric keypad with a range of numbers , such as 0 to 9, displayed as individual selectable virtual buttons. A user may be required to enter the parameter by tapping, tapping twice, tapping and dragging individually, etc. the desired numbers. Once the desired value has been entered by a user, a user may be required to tap, tap twice, etc. a virtual "confirm", "enter" button to fill in the field.

[000966] As indicated by the curved double arrows, some parameter input fields displayed in GUI 3300 may be dependent on each other. As in previous examples, the drug quantity in container parameter input field 3304, the total volume in container parameter input field 3306, and the concentration parameter input field 3308 may be dependent on each other. In Figure 315, the weight parameter input field 3320, the dose estimator parameter input field 3318, the rate parameter input field 3312, the VTBI parameter input field 3314, and the of time parameter 3316 are all dependent on each other. When sufficient information has been user-defined in these parameter input fields, parameter input fields not populated by the user can be automatically calculated and displayed in the GUI 3300.

[000967] In some embodiments, a user may be required to define a specific parameter input field even if sufficient information has been defined to automatically calculate the field. This can improve usage safety by presenting more opportunities for user errors to be caught. If a value entered by a user is not compatible with values already defined, the 3300 GUI may display an alert or alarm message prompting the user to double-check values that the user has entered.

[000968] In some situations, delivery of the infusion substance may be informed by a patient's body surface area (BSA). In Figure 316, the GUI 3300 has been adjusted for an infusion based on body surface area. As shown, a BSA 3322 parameter input field can be displayed in the GUI 3300. Parameter input fields can be defined by a user as detailed in the discussion above. In the exemplary embodiment, the infusion substance in medication parameter input field 3302 was defined as "FLUOROURACYL". The left field of the drug quantity parameter input field in container 3304 was set to "1,700". The right field of the drug quantity parameter input field in container 3304 was set to "mg". The total volume in the container parameter input field 3306 has been set to "500" ml. The left field of the concentration parameter input field 3308 was set to "3.4". The right field of the concentration parameter input field 3308 was set to "mg/ml". The parameter input field of BSA 3320 has been set to "1.7" m2. The left field of the dose rate parameter input field 3318 was set to "1000". The right field of the 3318 dose rate parameter input field was set to "mg/m2/day". Rate parameter input field 3312 was set to "20.8" ml/hour. The parameter input field of VTBI 3314 has been set to "500" ml. Time parameter input field 3316 has been set to "24" hours "00" minutes. The dependent parameter input fields are the same as in Figure 309 with the exception that the BSA parameter input field 3322 has taken the place of the weight parameter input field 3320.

[000969] To populate the BSA 3322 parameter input field, the user may tap or tap the BSA 3322 parameter input field on the GUI 3300. In some embodiments, this may select a numeric keypad with a range of numbers , such as 0 to 9, displayed as individual selectable virtual buttons. In some embodiments, the numeric keypad and any of the numeric keypads detailed above may feature symbols such as a decimal point. A user may be required to enter the parameter by tapping, tapping twice, tapping and dragging individually, etc. the desired numbers. Once the desired value has been entered by a user, a user may be required to tap, tap twice, etc. a virtual "confirm", "enter" button to fill in the field.

[000970] In some embodiments, a patient BSA may be automatically calculated and displayed in the GUI 3300. In such embodiments, the GUI 3300 may query the user for information about the patient when a user taps, taps, etc. the parameter input field of BSA 3322. For example, the user may be asked to define a patient's height and body weight. After the user defines these values, they can be used in a suitable formula to find the patient's BSA. The calculated BSA can then be used to populate the BSA parameter input field 3322 in the GUI 3300.

[000971] During operation, the values displayed in the parameter input fields may change during the course of a programmed infusion to reflect the current state of the infusion. For example, as infusion substance is introduced into a patient, the values displayed by GUI 3300 in the drug quantity in container parameter input field 3304 and the total volume in container parameter input field 3306 may drop to reflect the volume of the remaining contents of the container. Additionally, the values in the VTBI parameter input field 3314 and the time parameter input field 3316 may also drop as the infusion substance is introduced into the patient.

[000972] Figure 317 is an exemplary rate over time graph detailing the behavioral configuration of a pump 3201, 3202, 3203 (see Figure 303) during the course of an infusion. The graph in Figure 317 details an exemplary behavioral configuration of a pump 3201, 3202, 3203 in which the infusion is a continuous infusion (an infusion with a dose rate). As shown, the graph in Figure 317 starts at the beginning of the infusion. As shown, the infusion is administered at a constant rate over a period of time. As the infusion progresses, the amount of infusion substance remaining is depleted. When the amount of infusion substance reaches a predetermined threshold, an "INFUSION NEAR END ALERT" may be triggered. The "INFUSION NEAR END ALERT" may be in the form of a message on the 3300 GUI and may be accompanied by flashing lights, and audible noises such as a series of beeps. The "INFUSION NEAR END ALERT" gives time for the nursing and pharmacy assistant to prepare the materials to continue the infusion if necessary. As shown, the infusion rate may change with the "INFUSION ALERT TIME NEAR END".

[000973] When pump 3201, 3202, 3203 (see Figure 303) has introduced VTBI into a patient a "ZERO VTBI ALERT" may be triggered. The "ZERO VTBI ALERT" may be in the form of a message on the GUI 3300 and may be accompanied by flashing lights and audible noises such as beeps. As shown, "ZERO VTBI ALERT" causes the pump to switch to a keep-vein-open rate (hereinafter KVO) until a new container of infusion substance can be placed in place. The KVO rate is a low infusion rate (e.g., 5 to 25 ml/hour). The rate is adjusted to keep the infusion site unobstructed until a new infusion can be started. The KVO rate is configurable by group (will be elaborated later) or medication and can be modified on the pump 3201, 3202, 3203. The KVO rate is not allowed to exceed the continuous infusion rate. When the KVO rate can no longer be sustained and air reaches the pump channel an "INLINE AIR ALERT" may be triggered. When the "LINE AIR ALERT" is triggered, the entire infusion may stop. The "LINE AIR ALERT" may be in the form of a message on the 3300 GUI and may be accompanied by flashing lights and audible noises such as beeps.

[000974] Figure 318 shows another exemplary rate-over-time graph that details a behavioral configuration of a pump 3201, 3202, 3203 (see Figure 303) during the course of an infusion. The graph in Figure 318 details an exemplary behavioral configuration of a pump 3201, 3202, 3203 in which the infusion is a continuous infusion (an infusion with a dose rate). The alerts in the graph shown in Figure 318 are identical to the alerts shown in the graph in Figure 317. The conditions that propagate the alerts are also identical. The rate, however, remains constant throughout the graph until the "LINE AIR ALERT" is triggered and the infusion stops. Setting the pump to continue the infusion at a constant rate may be desirable in situations where the infusion substance is a drug with a short half-life. By continuing the infusion at a constant rate, it is ensured that the blood plasma concentration of the drugs remains at therapeutically effective levels.

[000975] Pump 3201, 3202, 3203 (see Figure 303) can also be used to deliver a primary or secondary intermittent infusion. During an intermittent infusion, a quantity of a drug (dose) is administered to a patient as opposed to a continuous infusion where the drug is given at a specified dose rate (amount/time). An intermittent infusion is also delivered over a set period of time; however, the time period and dose are independent of each other. The previously described Figure 313 shows an adjustment of the GUI 3300 for a continuous infusion. The previously described Figure 314 shows an adjustment of the GUI 3300 for an intermittent infusion.

[000976] Figure 319 is an exemplary rate-over-time graph detailing a behavioral configuration of a pump 3201, 3202, 3203 (see Figure 303) during the course of an intermittent infusion. As shown, the intermittent infusion is given at a constant rate until all of the infusion substance scheduled for the intermittent infusion has been used up. In the exemplary behavioral configuration, the pump 3201, 3202, 3203 was programmed to issue a "ZERO VTBI ALERT" and stop the infusion when all of the infusion substance has been dispensed. In this configuration, the user may be required to manually clear the alert before another infusion can be started or resumed.

[000977] Other configurations may cause a pump 3201, 3202, 3203 (see Figure 303) to behave differently. For example, in situations where the intermittent infusion is a secondary infusion, the pump 3201, 3202, 3203 can be configured to communicate with its companion pumps 3201, 3202, 3203 and automatically switch back to the primary infusion after issuing a notification. that the secondary intermittent infusion has been completed. In alternative configurations, the pump can be configured to issue a "ZERO VTBI ALERT" and reduce the infusion rate to a KVO rate after completing the intermittent infusion. In such configurations, the user may be required to manually clear the alert before a primary infusion is resumed.

[000978] A bolus can also be delivered as an intermittent primary infusion when it may be necessary or desirable to achieve a higher drug concentration in blood plasma or to manifest a more immediate therapeutic effect. In such cases, the bolus may be delivered by the pump 3201, 3202, 3203 (see Figure 303) which performs the primary infusion. The bolus can be delivered from the same container from which the primary infusion is being delivered. A bolus can be delivered at any point during an infusion as long as there is sufficient infusion substance to deliver the bolus. Any volume derived via a bolus to a patient is included in the value displayed by the primary infusion VTBI 3314 parameter input field.

[000979] Depending on the infusion substance, a user may be prohibited from performing a bolus. The dosage of a bolus can be adjusted in advance depending on the specific infusion substance that will be used. Additionally, the period of time in which the bolus occurs can be predefined depending on the infusion substance that will be used. In some embodiments, a user may be able to adjust these presets by adjusting various settings on the GUI 3300. In some situations, such as those in which the drug being introduced has a long half-life (vancomycin, teicoplanin, etc.) ), a bolus can be given as a loading dose to more quickly achieve a therapeutically effective blood plasma drug concentration.

[000980] Figure 320 shows another rate graph over the time in which the flow rate of the infusion substance was titrated to "step up" the infusion substance to the patient. Titration is often used with drugs that have a rapid therapeutic effect but have a short half-life (such as norepinephrine). During titration, the user can adjust the delivery rate of the infusion substance until the desired therapeutic effect is manifested. Each adjustment can be checked against a series of limits defined for the specific infusion substance being administered to the patient. If an infusion is changed by more than a preset percentage, an alert may be issued. In the example graph shown in Figure 320, the rate had the titration increased once. If necessary, the title fee may be increased more than once. Additionally, in cases where titration is being used to "taper" a drug in a patient, the rate can be titrated down any appropriate number of times.

[000981] Figure 321 is another rate over time graph where the infusion was configured as a multi-step infusion. A multi-stage infusion can be programmed in numerous stages. Each step can be defined by a VTBI, time and a dose rate. Multi-step infusions may be useful for certain types of infusion substances such as those used for parenteral nutrition applications. In the example graph shown in Figure 321, the infusion was configured as a five-step infusion. The first step introduces a "VTBI 1" for a length of time, "Time 1", at a constant rate, "Rate 1". When the time interval for the first step has elapsed, the pump moves to the second step of the multi-step infusion. The second step introduces a "VTBI 2" for an extension of time, "Time 2", at a constant rate, "Rate 2". As shown, "Rate 2" is greater than "Rate 1". When the time interval for the second step has elapsed, the pump moves to the third step of the multi-step infusion. The third step introduces a "VTBI 3" for an extension of time, "Time 3", at a constant rate, "Rate 3". As shown "Rate 3" is the highest rate of any of the steps in the multi-step infusion. "Time 3" is also the longest duration of any of the steps in the multi-step infusion. When the time interval for the third step has elapsed, the pump moves to the fourth step of the multi-step infusion. The fourth step introduces a "VTBI 4" for an extension of time, "Time 4", at a constant rate, "Rate 4". As shown, "Rate 4" had a reduction in title from "Rate 3". "Rate 4" is approximately the same as "Rate 2". When the time interval for the fourth step of the multi-step infusion has elapsed, the pump moves to the fifth step. The fifth step introduces a "VTBI 5" for an extension of time, "Time 5", at a constant rate, "Rate 5". As shown, "Rate 5" has been de-titled from "Rate 4" and is approximately the same as "Rate 1".

[000982] The "INFUSION NEAR END ALERT" is triggered during the fourth stage of the exemplary infusion shown in Figure 321. At the end of the fifth stage and in the final stage of the multi-stage infusion, the "ZERO VTBI ALERT" is triggered . In the exemplary configuration in the graph in Figure 321, the rate drops to a KVO rate after the multi-step infusion has been completed and the "ZERO VTBI ALERT" has been issued. Other settings may differ.

[000983] Each rate change in a multi-step infusion can be administered in a variety of different ways. In some configurations, the pump 3201, 3202, 3203 (see Figure 303) may display a notification and automatically adjust the rate to move to the next step. In other configurations, the pump 3201, 3202, 3203 may issue an alert before changing the rate and wait for user confirmation before adjusting the rate and moving to the next step. In such configurations, the pump 3201, 3202, 3203 may stop infusing or drop to a KVO rate until user confirmation has been received.

[000984] In some embodiments, the user may be able to pre-program infusions. The user can pre-program an infusion to begin automatically after a fixed time interval has elapsed (e.g. 2 hours). The infusion can also be programmed to start automatically at a specific time of the day (for example, 12:30 p.m.). In some embodiments, the user may be able to program the pump 3201, 3202, 3203 (see Figure 303) to alert the user with a callback function when it is the previously programmed infusion time. The user may need to confirm the start of the previously programmed infusion. The callback function may be a series of audible beeps, flashing lights, or the like.

[000985] In arrangements where there is more than one pump 3201, 3202, 3203 (see Figure 303), the user may be able to program a relay infusion. The relay infusion can be programmed so that after a first pump 3201, 3202, 3203 has completed its infusion, a second pump 3201, 3202, 3203 can automatically begin a second infusion, and so on. The user can also program a relay infusion so that the user is alerted via the callback function before the relay occurs. In such a scheduled arrangement, relay infusion may not begin until a user's confirmation has been received. A pump 3201, 3202, 3203 may start at a KVO rate until user confirmation has been received.

[000986] Figure 322 shows an example of the block diagram of a "Drug Administration Library". In the upper right corner, there is a box that is substantially rectangular, although its edges are rounded. The box is associated with the name "General Settings". "General Settings" may include settings that would be common to all devices in a facility such as location name (e.g. Hospital XZY), language, common passwords and the like.

[000987] In Figure 322, the "Drug Administration Library" has two boxes that are associated with the names "Group Settings (ICU)" and "Group Settings". These boxes were the headers for their own columns. These boxes can be used to define a group within a facility (e.g., pediatric intensive care unit, emergency room, subacute care, etc.) in which the device is placed. Groups can also be areas outside a main facility, for example, a patient home or inter-hospital transport such as an ambulance. Each group can be used to adjust specific settings for multiple groups in an installation (weight, titer, limits, etc.). These groups can alternatively be defined in other ways. For example, groups can be defined by user training level. The group may be defined by a previously designated individual or any of a number of previously designated individuals and changed if the patient or associated device is moved from one specific group in a facility to another.

[000988] In the exemplary embodiment, the left column is "Group Settings (ICU)" which indicates that the peristaltic pump 2990 is placed in the intensive care unit of the facility. The right column is "Group Settings" and has not been further defined. In some embodiments, this column may be used to designate a subgroup, e.g., operator training level. As indicated by lines extending to the box on the left of the block diagram from the "Group Settings (ICU)" and "Group Settings" columns, the settings for these groups may include a preset number of default settings.

[000989] Group settings may include patient weight limits, patient BSA limits, air alarm sensitivity, occlusion sensitivity, default KVO rates, VTBI limits, etc. group settings may also include parameters such as whether a review of a scheduled infusion is required for high-risk infusion substances, whether the user needs to identify themselves before starting an infusion, whether the user needs to enter a text comment after a limit has been overridden, etc. A user can also set default values for various attributes such as screen brightness or speaker volume. In some embodiments, a user may be able to program the screen to automatically adjust screen brightness relative to one or more conditions such as, but not limited to, time of day.

[000990] Also shown to the left of the block diagram in Figure 322, each facility may have a "Master Medication List" that defines all infusion substances that may be used in the facility. The "Master Medication List" may comprise a number of medications that a qualified individual may upgrade or maintain. In the exemplary modality, the "Main Medication List" only has three medications: Heparin, 0.9% Normal Saline and Alteplase. Each group in a facility may have its own list of medications used within the group. In the exemplary embodiment, the "Group Medication List (ICU)" includes only a single medication, Heparin.

[000991] As shown, each medication can be associated with one or numerous clinical uses. In Figure 322 the "Clinical Use Records" are defined for each medication in a group medication list and appear as an expanded subheading for each infusion substance. Clinical uses can be used to adapt limits and previously define adjustments for each clinical use of the infusion substance. For Heparin, weight-based dosing and non-weight-based dosing are shown in Figure 322 as possible clinical uses. In some embodiments, there may be a "Clinical Use Record" setting that requires the user to review or re-enter a patient weight (or BSA) before beginning an infusion.

[000992] Clinical uses can also be defined for different medical uses of each infusion substance (e.g., stroke, heart attack, etc.) instead of or in addition to the infusion substance dose mode. Clinical use can also be used to define whether the infusion substance is given as a continuous primary infusion, intermittent primary infusion, secondary infusion, etc. They can also be used to provide appropriate limits for dose, rate, VTBI, time duration, etc. Clinical uses may also provide titration change limits, bolus availability, loading dose availability, and many other infusion-specific parameters. In some embodiments, it may be necessary to provide at least one clinical use for each infusion substance in the group medication list.

[000993] Each clinical use may additionally comprise another subheading in which the concentration may also be defined. In some cases, there may be more than one possible concentration of an infusion substance. In the exemplary embodiment in Figure 322, the clinical use of weight-based dosing has a concentration of 400 mg/250 ml and a concentration of 800 mg/250 ml. Clinical use of non-weight-based dosing has only one concentration, 400 mg/ml. Concentrations can also be used to define an acceptable range for instances in which the user can standardize the concentration of the infusion substance. The concentration adjustment may include information about the drug concentration (as shown), the volume of diluents, or other related information.

[000994] In some embodiments, the user can navigate to the "Drug Administration Library" to fill in some of the parameter input fields shown in Figures 312 to 316. The user can also navigate to the "Drug Administration Library" Drug” to choose from clinical uses for each infusion substance which type of infusion the 2990 peristaltic pump will administer. For example, if a user were to select the weight-based Heparin dosage in Figure 322, the GUI 3300 could display the infusion programming screen shown in Figure 315 with "Heparin" populated in the medication parameter input field 3302. Selecting a clinical use of a drug may prompt a user to select a drug concentration. This concentration can then be used to populate the concentration parameter input field 3308 (see Figures 312316). In some embodiments, the "Drug Delivery Library" may be updated and maintained external to the peristaltic pump 2990 and communicated to the peristaltic pump 2990 through suitable means. In such embodiments, the "Drug Delivery Library" may not be changeable on the peristaltic pump 2990, but may only place limits and/or restrictions on programming options for a user who completes the parameter input fields shown in Figures 312 through 316.

[000995] As mentioned above, by choosing a medication and clinical use from the list of group medications, a user may also be adjusting limits on other parameter input fields for infusion programming screens. For example, by defining a medication in the "Drug Administration Library", a user can also define limits for the dose parameter input field 3310, the dose rate parameter input field 3318, the rate parameter input field 3312, VTBI parameter input field 3314, time parameter input field 3316, etc. These limits can be defined in advance for each clinical use of an infusion substance prior to a user scheduling an infusion. In some embodiments, the limits may have both a soft limit and a hard limit where the hard limit is the ceiling for the soft limit. In some embodiments, group adjustments may include limits on all medications available to the group. In such cases, clinical use limits can be defined to further tailor group limits for each clinical use of a particular medication.

EXAMPLE BATTERY AND SPEAKER TEST

[000996] Figure 323 shows a circuit diagram 13420 that has a speaker 3615 and a battery 3420 in accordance with an embodiment of the present description. The battery 3420 may be a backup battery 3450 (Figure 325A) and/or the speaker 3615 may be a backup alarm speaker 3468 (Figure 325B). That is, circuit 13420 may be a backup alarm circuit, for example, a backup alarm circuit in a medical device such as a peristaltic pump 2900.

[000997] In some embodiments of the present disclosure, the battery 3420 can be tested simultaneously with the speaker 3615. When a switch 13422 is in an open position, a voltmeter 13425 can be used to measure the open circuit voltage of the battery 3420 After this, switch 13422 can be closed and the closed circuit voltage from battery 3420 can be measured. The internal resistance of the battery 3420 can be estimated using the known impedance, Z, of the speaker 3615. A processor can be used to estimate the internal resistance of the battery 3420 (e.g., a processor of a peristaltic pump 2900). The processor may correlate the internal resistance of the battery 3420 to the health of the battery 3420. In some embodiments of the present disclosure, if the closed-circuit voltage of the battery 3420 is not in a predetermined range (the range may be a function of the open-circuit voltage of battery 3420), speaker 3615 may be determined to have failed.

[000998] In some additional embodiments of the present disclosure, switch 13422 may be modulated so that speaker 3615 is tested simultaneously with battery 3420. A microphone 3617 may be used to determine whether speaker 3615 is transmitting audibly a signal within predetermined operating parameters (e.g., volume, frequency, spectral compositions, etc.) and/or the internal impedance of battery 3420 may be estimated to determine whether it is within predetermined operating parameters (e.g., the impedance complex, for example). The 3617 microphone (Figure 325C) can be coupled to the processor. Additionally or alternatively, a test signal may be applied to speaker 3615 (e.g., by modulating switch 13422) and the current waveform of speaker 3615 may be monitored by a current sensor 13426 to determine the total harmonic distortion of the 3615 speaker and/or the magnitude of the current; a processor may monitor these values using current sensor 13426 to determine whether a fault condition exists in speaker 3615 (e.g., total harmonic distortion or current magnitude is not within predetermined ranges).

[000999] Various sine waves, periodic waveforms and/or signals perhaps applied to the speaker 3615 to measure its impedance and/or to measure the impedance of the battery 3420. For example, a peristaltic pump processor 2900 disclosed in herein can modulate switch 13422 and measure voltage across battery 3420 to determine whether battery 3420 and speaker 3615 have an impedance in predetermined ranges; If the estimated impedance of the battery 3420 is outside a first range, the processor may determine that the battery 3420 is in a fault condition, and/or if the estimated impedance of the speaker 3615 is outside a second range, the processor may determine that the 3615 speaker is in a fault condition. Additionally or alternatively, if the processor cannot determine whether battery 3420 or speaker 3615 has a fault condition, but has determined that at least one exists in a fault condition, the processor may issue an alert or alarm that circuit 13420 is in a fault condition. The processor may issue an alarm or alert to a user or a remote server of the fault condition. In some embodiments of the present disclosure, the peristaltic pump 2990 will not operate until the fault has been addressed, mitigated and/or corrected.

ELECTRICAL SYSTEM

[0001000] The electrical system 4000 of the peristaltic pump 2990 is described in a block diagram in Figures 324, 325A to 325G. The electrical system 4000 controls the operation of the peristaltic pump 2990 based on inputs from the user interface 3700 and sensors 3501. The electrical system 4000 may be a power system comprising the main chargeable battery 3420 and the charging battery 3422 that connects to the AC network. The electrical system 4000 may be architected to provide safe operation with redundant safety checks and allow the peristaltic pump 2990 to operate in fail-safe operating modes for some errors and fail-safe for the rest.

[0001001] The high-level architecture of an electrical system 4000 is shown in Figure 324. The electrical system 4000 can be used to control, operate, monitor, or be used with the pump 2990 shown in Figure 255 (or any other pump described in this document). In one example, the electrical system 4000 comprises two main processors, a real-time processor 3500 and a User Interface and Security processor 3600. The electrical system may also comprise a supervisory circuit 3460, motor control elements 3431, 3501 sensors and input and output elements. A main processor, referred to as the Real-Time Processor (RTP) 3500, can control the speed and position of the motor 3072 that drives the plunger 3091 and the valves 3101, 3111. The RTP 3500 controls the engine 3072 based on input from the sensors 3501 and commands from the user interface & security processor (UIP) 3600. The UIP 3600 can manage telecommunications, manage the user interface 3701, and provide security checks on the RTP 3500. The UIP 3600 estimates the pumped volume based on the output of a motor decoder 3438 and may signal an alarm or alert when the estimated volume differs more than a specified amount from a desired volume or the volume reported by the RTP 3500. The 3460 supervision circuit monitors the operation of the RTP 3500. If the RTP 3500 fails to perform the 3460 supervision on time, the 3460 supervision may disable the motor controller, sound an alarm, and turn on fault lights on the 3701 user interface. sensor 3130 can measure the rotational position of camshaft 3080 and plunger 3901. The RTP 3500 can use the sensor inputs to control the position and speed of engine 3072 in a closed-loop controller as described below. Telecommunications may include a WIFI antenna and unit to communicate with a host computer or accessories, a BLUETOOTH ® antenna and unit to communicate with accessories, cell phones, etc. and an antenna and Near Field Communication (NFC) unit for RFID tasks and a BLUETOOTH ®. In Figure 324, these components are collectively referred to with reference number 3721. User interface 3701 may include a display, a touch screen, and one or more buttons for communicating with the user.

[0001002] The detailed components and electrical connections of the electrical system 4000 are shown in Figure 325A to 325G. Sensors 3130, 3530, 3525, 3520 and part of the RTP 3500 are shown in Figure 325A. Sensors monitoring the peristaltic pump 2990 that are connected to the RTP 3500 may comprise the rotary position sensor 3130 that monitors the cam shaft position and two linear encoders 3520, 3525 that measure the position of the plunger 3091 as shown. One linear encoder 6001 measures the position of the magnet (3196 in Figures 268 and 282) on the upstream side of the plunger 3091. The other linear encoder 6002 measures the position of a second magnet 3197 (see Figures 268 and 282) on the downstream side of plunger 3091. In another embodiment, the position of the plunger can be measured with a single magnet and linear encoder. Alternatively, the RTP 3500 can use the output of only one linear encoder if the other fails. A thermistor 3540 provides a signal to the RTP 3500 indicative of the temperature of infusion tube 3210. Alternatively the thermistor 3540 can measure a temperature in the peristaltic pump 2990.

[0001003] As shown, any suitable component part numbers of the electrical system 4000 may be used. For example, thermistor 3540 could be a "THERMISTOR 2X SEMITEC 103JT050 ADMIN Set". However, the electrical system 4000 is not limited to any particular set of part numbers and the present description should not be construed as limiting the components of the electrical system 4000 to a particular part number. In various embodiments, suitable replacement components may be used in place of a component of the electrical system shown in Figures 325A to 325G. In some embodiments, the electrical system 4000 may comprise additional components. In some embodiments, the electrical system 4000 may comprise fewer components than the number of components shown in Figures 325A to 325G.

[0001004] The two infusion tube sensors located downstream of the peristaltic pump 2990, an in-line air sensor 3545 and an occlusion sensor 3535 can be connected to the RTP 3500. An in-line air sensor 3545 detects the presence of air in the infusion tube section 3210 proximate the in-line air sensor 3545. In one example, the in-line air sensor 3545 may comprise an ultrasonic sensor 3545B, a logic unit 3545A, and a signal conditioning unit 3545C.

[0001005] The occlusion sensor 3535 measures the internal pressure of the fluid in the infusion tube 3535. In an exemplary embodiment, the occlusion sensor 3535 may comprise a force sensor 3535B, a current excitation IC 3535A, a signal amplifier 3535C and a 3535D temporary data store. The 3535D temporary data storage chip can protect the RTP 3500 from excess voltages due to high pressure forces applied to the 3535B force sensor.

[0001006] The 3460 supervision circuit is shown in Figures 325A to 325C. The supervision circuit is enabled by a 12C command from the RTP 3500. The supervision circuit 3460 can signal an error and disable the 3430 motor control if it does not receive a signal from the RTP 3500 at a specified frequency. The 3460 supervisory circuit can signal the user by means of an audible alarm. The audible alarm may be output through an amplifier 3464 and/or backup speaker 3468. The supervisory circuit 3460 may signal the user with visual alarm LEDs 3750 (shown in Figure 325D). In one embodiment, the RTP 3500 must "release" the supervisory circuit 3460 between 10 ms and 200 ms after the last release of the supervisory circuit. In one embodiment, the supervisory circuit 3460 comprises a window supervision 3450A, a logic circuit 3460B including one or more flip-flop switches, and an expander 3460C that communicates with the RTP 3500 on a bus 12C. A backup battery 3450 provides power to the supervisory circuit 3460 and the backup speaker system (which may comprise an audio amplifier 3464, and a backup speaker 3468) in the event that the main battery 3420 fails. The 3450 backup battery provides power to the RTP 3500 and UIP 3600 to maintain internal time measurement, which may be especially desirable when the 3420 main battery is changed. The RTP 3500 can also monitor the voltage of the backup battery 3450 with a switch such as "FAIRCHILD LOAD SWITCH FPF1005 LOAD SWITCH" 3452 shown in Figure 325A.

[0001007] The RTP 3500 directly controls the speed and position of the 3072 engine, which controls the position and speed of the piston and valves. The 3072 motor can be one of a number of motor types that include a brushed DC motor, a stepper motor, or a brushless DC motor. In the embodiment illustrated in Figures 325 to 325G, the peristaltic pump 2990 is driven by a brushless direct current (BLDC) servomotor 3072 in which the rotary position sensor 3130 measures the position of the cam shaft. In an exemplary embodiment, the RTP 3500 receives signals from Hall effect sensors 3436 of a brushless DC motor 3072 and makes calculations to switch power to the coils of the motor 3072 to achieve a desired speed or position. The switching signals are sent to the motor driver 3430 which selectively connects the coils to the motor power supply 3434. The motor 3072 is monitored for damaging or hazardous operation by means of current sensors 3432 and a temperature sensor 3072a.

[0001008] Signals from Hall effect sensors 3436 can be supplied to either the RTP 3500 or an encoder 3438. In one embodiment, three Hall effect sensor signals are generated. Any two of the three signals are sent to the encoder 3438. The encoder 3438 may use these signals to provide a signal position to the UIP 3600. The UIP 3600 estimates the total volume of fluid delivered by the peristaltic pump 2990 by interpreting the signal position of the encoder 3438. The UIP 3600 estimates total volume by multiplying the number of complete cam revolutions times a given stroke volume. The UIP 3600 total volume estimate assumes that each plunger stroke supplies the given amount of fluid. The amount of fluid supplied per stroke is determined empirically during development and stored in memory. Alternatively, each 2990 peristaltic pump can be calibrated during assembly to establish the nominal volume/stroke that can be stored in memory. The volume estimated by UIP 3600 can then be compared at regular intervals to the expected volume of the commanded therapy. In some embodiments, the interval between comparisons may be shorter for specific infusion substances, e.g., short half-life infusion substances. The therapy can specify, among other parameters, a flow rate, a duration or a total volume to be introduced (VTBI). In any case, the expected volume for a scheduled therapy at a given time during that therapy can be calculated and compared to the volume estimated by the UIP 3600. The UIP 3600 can signal an alert if the difference between the volume estimated by the UIP 3600 and the volume Expected therapy is outside the predefined threshold. The UIP 3600 may signal an alarm if the difference between the volume estimated by the UIP 3600 and the expected therapy volume is outside another predefined threshold.

[0001009] The UIP 3600 can also compare the estimated volume with the volume reported by the RTP 3500. The UIP 3600 can signal an alert if the difference between the volume estimated by the UIP 3600 and the volume reported by the RTP 3500 is outside a predefined threshold . The UIP 3600 may signal an alarm if the difference between volume estimated by UIP 3600 and the volume reported by RTP 3500 is outside a second threshold.

[0001010] The UIP 3600 may also understand the estimated rotation angles or number of rotation pulses reported by the RTP 3500. The UIP 3600 may signal an alert if the difference between the rotation angles or number of rotation pulses estimated by the UIP 3600 and the value reported by RTP 3500 is outside a predefined threshold. The UIP 3600 may signal an alert if the difference between the UIP 3600 and the RTP 3500 value is outside a third threshold.

[0001011] In some embodiments, the UIP 3600 may compare the volume reported by RTP 3500 with the expected therapy volume and signal an alert if the two values differ by more than a predefined threshold. The UIP 3600 may signal an alarm if the difference between the volume reported by RTP 3500 and the expected therapy volume differs by more than a predefined threshold. Alert and alarm threshold values may be different for comparisons between different sets of volumes that include the volume estimated by UIP 3600, the volume calculated by RTP 3500, and the expected therapy volume. Thresholds can be stored in memory. Thresholds may vary depending on a number of other parameters, such as, but not limited to, medication, medication concentration, type of therapy, clinical use, patient or location. Thresholds can be added to the DERS database and downloaded from the device gateway server.

[0001012] The slide claw sensor or slide occluder 3152 and the door sensor 3162 communicate with both the RTP 3500 and the UIP 3600 as shown in Figures 325B, 325F. In one embodiment, the sensors are magnetically null sensors that change state when, for example, the slide occluder 3200 is detected or the latch hook door 3025C engages the pump body. The RTP 3500 or the UIP 3600 can enable the motor power supply 3434 only while the processors receive signals indicating that the slide occluder 3200 is in place and the port installation 3021 is properly closed.

[0001013] An RFID beacon 3670 (Figure 325C) can be connected via a 12C bus to the UIP 3600 and a nearby field antenna 3955. The RFID beacon 3670 can be used by medical technicians or other users or personnel to acquire or store information when the 2990 peristaltic pump is in an unpowered state. The UIP 3600 can store service records or error codes on the RFID Beacon 3670 that can be accessed by an RFID reader. A medical technician, for example, could inspect non-powered peristaltic pumps 2990 in storage or evaluate non-functioning peristaltic pumps 2990 using an RFID reader to interrogate the RFID beacon 3670. In another example, a medical technician might perform service in the peristaltic pump 2990 and store the related service information in the RFID beacon 3670. The UIP 3600 can pull the latest service information from the RFID beacon 3670 and store the same in memory 3605.

[0001014] The main battery 3420 can feed all power to the peristaltic pump 2990. The main battery 3420 is connected via a system power transmission element 3424 to the motor power supply 3434. All sensors and processors can be powered by one of several voltage regulators 3428. The main battery 3420 is charged from AC power via a battery charger 3422 and an AC/DC converter 3426. The UIP 3600 can be connected to one or more 3605 memory chips.

[0001015] The UIP 3600 controls the main audio system comprising a main speaker 3615 and audio chips 3610, 3612. The main audio system may have the ability to produce a range of sounds that indicate, for example, alerts and alarms. The audio system may also provide confirmation sounds to facilitate and enhance user interaction with the touch screen 3755 and display 3725. The main audio system may include a microphone 3617 that may be used to confirm the operation of the speaker. -main speaker 3615 as well as backup speaker 3468. The main audio system may produce one or more tones, patterns and/or sound modulation sequences and the audio codec chip 3610 may compare the signal received from microphone 3617 with the signal sent to main speaker 3615. Using one or more tones and comparing signals may allow the system to confirm main speaker function 3615 regardless of ambient noise. Alternatively, the UIP 3600 or the audio codec 3610 may confirm that the microphone 3617 produced a signal at the same time that a signal was sent to the amplifier speaker 3612.

[0001016] The UIP 3600 can provide a range of different wireless signals for different uses. The UIP 3600 can communicate with the hospital wireless network via a dual-band WIFI using chips 3621, 3620 and 3622 and antennas 3720, 3722. The spatially diverse dual antenna may be desirable due to the fact that it can having the ability to overcome dead spots in a room due to multiple trajectories and cancellations. A device communication port can communicate DERS (Drug Error Reduction System), CQI (Continuous Quality Improvement), prescriptions, etc. to the 2990 peristaltic pump via the wifi system.

[0001017] The BLUETOOTH® system, which utilizes the same chips 3621, 3620 and 3622 and antennas 3720, 3722, provides a convenient method for connecting aids to the peristaltic pump 2990 that may include pulse oximeters, blood pressure readers, barcode devices, tablet computers, telephones, etc. BLUETOOTH ® may include version 4.0 to enable low power aids that may communicate with the 2990 peristaltic pump periodically such as, for example, a continuous glucose meter that sends an update once per minute.

[0001018] The NFC system comprises an NFC controller 3624 and an antenna 3724. The controller 3624 can also be referred to as an RFID reader. The NFC system can be used to read RFID chips that identify pharmaceuticals or other inventory information. RFID beacons can also be used to identify patients and nursing assistants. The NFC controller 3624 can also interact with a similar RFID reader on, for example, a phone or tablet computer to enter information including prescriptions, bar code information, patient, nursing assistant identities, etc. . The NFC controller 3624 can also provide information to the telephone or tablet computers such as peristaltic pump 2990 history or service conditions. The RFID antennas 3720 and 3722 or the NFC antenna 3724 may be preferably located around or near the display screen so that all interaction with the pump occurs at or near the display face whether reading an RFID beacon or interacting with the display touch screen 3725, 3735.

[0001019] The UIP 3600 may include a medical grade connector 3665 so that other medical devices can be connected to the peristaltic pump 2990 and provide additional capabilities. The 3665 connector can implement a USB interface.

[0001020] Display 3700 includes antennas 3720, 3722, 3725, touch screen 3735, LED indicator lights 3747, and three buttons 3760, 3765, 3767. Display 3700 may include a backlight 3727 and an ambient light sensor 3740 to allow screen brightness to automatically respond to ambient light. The first button 3760 may be the "On" button, while the other button 3765 may be an infusion stop button. These buttons 3760, 3765, 3767 may not provide direct control of the peristaltic pump 2990, but provide a signal to the UIP 3600 to either start or end the infusion. The third button 3767 will silence the alarm on both the main speaker and secondary speaker. Silencing the alarm will not clear the fault, but will eliminate the audible alarm. The electrical system 4000 described above, or an alternative embodiment of the electrical system 4000 described above, can be used with any of the peristaltic pumps with linear position sensors.

CONTROLS

[0001021] The pumping algorithms provide substantially uniform flow by varying the rotational speed of the 3072 engine by one full revolution. At low flows, the motor 3072 rotates at a relatively high rate of speed during portions of the revolution when the plunger 3091 is not moving fluid toward the patient. At higher flow rates, the 3072 motor rotates at a nearly constant speed throughout the entire revolution to minimize power consumption. At high flow rates, the 3072 motor rotation rate is proportional to the desired flow rate. The pump algorithm utilizes linear encoders 3520, 3525 (Figure 325A) above plunger 3091 to measure the volume of fluid pumped toward the patient. The pump algorithm uses linear encoders 3520, 3525 (Figure 325A) above the plunger 3091, the rotation encoder 3130 (Figure 325A) near the cam shaft 3080, and the in-line air sensor 3545 downstream of the plunger 3091 to detect a or more of the following conditions: downstream occlusions, upstream occlusions/empty bag, leaks, and the amount of air directed to the patient.

[0001022] An embodiment of the position of valve openings 3101, 3111 and plunger 3091 is represented graphically in Figure 326. Three time periods are identified in Figure 326 including a refueling 826, a pressurization 835 and a delivery period 840. In addition Furthermore, a period "A" occurs between the pressurization period 835 and the delivery period 840 and period "B" occurs between the delivery period 840 and the refueling period 830. The inlet valve position 820, the position output valve position 825 and plunger position 815 are graphed in a sensor signal on the cam angle graph in a complete cam shaft rotation 3080.

[0001023] The refill period 830 occurs while the inlet valve 820 is retained from the infusion tube 3210 and the plunger 3091 is lifted from the infusion tube 3210 by the plunger cam 3083. The refill period 830 ends and the pressurization period 835 starts as inlet valve 3101 is closing. The plunger cam 3083 is completely retracted during the pressurization period 835 to allow the plunger 3091 to rest in the filled infusion tube 3210. The pressurization period 835 ends several degrees of cam angle beyond the point at which the plunger cam 3083 reaches its minimum value. After a waiting period "A", the piston cam 3083 lifts until it reaches the height at which the piston 3091 is expected to be. The delivery period 840 begins when the outlet valve 3111 begins to open and lasts until the outlet valve 3111 closes again. The plunger cam 3083 rotates, causing the plunger 3091 to descend during the delivery period 840 pushing the fluid toward the patient.

[0001024] In some embodiments, if the plunger 3091 moves toward the press 3022 (see Figures 257 and 259) at a predetermined rate (i.e., a speed of the plunger 3091) during the pressurization period 837, the RTP 3500 may determine that at least one of the inlet valve 3101 and the outlet valve 3111 is leaking. Additionally, alternatively or optionally, an underfill condition (a type of anomaly) may be considered by the RTP 3500 to have occurred if the static position of the plunger 3091 is beyond a threshold in the direction of a press 3022 (see Figure 296). during the pressurization period 837. The static position of the plunger 3091 during the pressurization period 837 is related to the amount of fluid within the tube. Therefore, if the tube is not filled with an expected amount of fluid, the position of the plunger 3091 during the pressurization period 837 will be closer to the press 3022 (see Figures 257 and 259). The underfill condition may be due to air in the tube, an upstream occlusion, or an empty fluid source attached to the tube. Air is easily compressed within the tube by plunger 3091. The in-line air detector 3066 (see Figure 257) can be used by the processor to distinguish an underfill caused by air within the tube under plunger 3091 from an underfill caused by by an upstream occlusion or an empty fluid source (such as an IV bag). The RTP 3500 can be coupled with the in-line air detector 3066 to determine a cause of underfill by examining how much air is within the discharged fluid when the fluid is discharged downstream by the plunger 3091 when the outlet valve 3111 (see Figures 257 and 260) is open. If the underfill was caused by air, the RTP 3500 should detect an amount of air that corresponds to the amount of movement of the 3091 plunger beyond the threshold. The RTP 3500 may use a lookup table to determine whether the amount of piston movement 3091 beyond the threshold corresponds to a range within the lookup table. If so, the RTP 3500 can determine which air caused the underfill. If not, the RTP 3500 may determine that an upstream occlusion and/or an empty fluid source caused the underfill. The cause of underfilling can be shown on display 2994 of pump 2990 (see Figure 255).

[0001025] The RTP 3500 can determine the volume of fluid delivered towards the patient for each stroke based on signals from the rotary encoder 3130 that measures the angle of the cam shaft 3080 and the position of the plunger 3091 from measurements of the linear encoder 3525, 3520. The volume of each stroke can be measured by subtracting the height of the piston 3091 at the end of the delivery period 840 from the height of the piston 3091 at the end of the pressurization period 835. The height of the piston 3091 can be determined from signals from a or both linear encoders 3020, 3025, wherein the height approximates the distance of the plunger tip 3091B from the plate 3022. The end of the delivery period 840 and the end of the pressurization period 835 can be determined from the rotary encoder 3130 which measures the angle of the crankshaft. The measured height difference 845 can be empirically associated with pumped volumes and the result stored in a lookup table or in memory in the controller. The volume versus stroke table can be determined during development and programmed into each 2990 peristaltic pump during manufacturing. Alternatively, the measured change in height of plunger 3091 can be calibrated to the volume pumped for each peristaltic pump 2990 or pumping mechanism 3000 during the manufacturing process.

[0001026] In one embodiment, the volume pumped is the plunger positions 3091 calibrated as: Vi = A + B * (hp - hD)

[0001027] where Vi is the pumped volume, A and B are fitting coefficients, hp is the position of the plunger 3091 30 at the end of the pressurization period 835 and hD is the position of the plunger 3091 at the end of the delivery period 840.

[0001028] The speed of the 3072 motor varies with flow rate and varies by a single revolution for lower flow rates. In one example, engine speed 3072 is relatively constant for flow rates commanded above approximately 750 ml/hour. The 3072 engine speed is controlled to relatively reduce speeds during intake and delivery flow rates for commanded flow rates below approximately 750 ml/hour.

[0001029] Engine 3072 moves at a constant speed during the pressurization period 835 for pumping rates. In one example, the 3072 motor rotates at the speed required to deliver fluid at the highest flow rate. In one example, the motor 3072 rotates at 800°/second during the pressurization period 835, which corresponds to the peristaltic pump 2990 to deliver 1200 ml/Hour. Running the engine 3072 at a fixed high speed during the pressurization period 835 can advantageously minimize periods of no flow which improves fluid flow uniformity. Running the motor 3072 at a fixed high speed during the pressurization period 835 can advantageously create a consistent measurement of the height of the infusion tube 3210 filled by compressing the plastic walls of the infusion tube 3210 at the same rate each time. Not limited to a single theory, one theory states that the plastic infusion tube 3210 continues to yield after being compressed, which would produce a lower height for the filled infusion tube 3210 the longer the time between compression and measurement. . The plastic can exhibit viscoelastic properties such that the amount of stress on the plastic changes with the compression ratio, which in turn would change the measured height of the plastic infusion tube 3210.

LOW FLOW MODE

[0001030] The pumping algorithm to produce a desired flow rate may control the speed of the engine 3072 differently during the refueling and delivery periods 830,840 for relatively lower flow rates compared to higher flow.

[0001031] In low flow mode, motor 3072 is controlled during delivery period 840 to control the position of cam shaft 3080 to produce a predetermined volume trajectory. The volume trajectory is the volume of fluid delivered to the patient versus time. The predefined volume trajectory generally occurs at many camshaft rotations 3080 such that the delivery period 840 needs to deliver fluid of one full revolution at the trajectory speed in the shortest delivery period 840 .

[0001032] Motor speed 3072 during refueling period 830 is adjusted to produce a complete infusion tube 3210 as measured at plunger position 3091 at the end of pressurization period 835. The controller will reduce motor speed 3072 if the 3210 infusion tube is not complete in the previous pump cycle. The refill period 830 is selected so that the plunger 3091 lifts from the hard stop 3022A (Figure 277) slowly (at lower flow rates) in order to minimize cavitation and air bubble generation.

[0001033] At all other times, the 3072 engine rotates at the Delivery Stroke Speed. Briefly, this is the speed at which the 3080 cam shaft needs to complete one revolution in order to keep up with the trajectory volume, limited to values greater than 500° per second.

HIGH FLOW MODE

[0001034] In high flow mode, refill and delivery periods 830, 840 occur at the Delivery Stroke Speed. The pressurization period 835 continues to occur at 800° per second. Delivery Stroke Speed is continually updated based on previous volume measurement.

DELIVERY SPEED

[0001035] Delivery Stroke Speed is the speed at which camshaft 3080 needs to rotate in order for the controller to maintain the requested flow rate. This value is limited to speeds greater than 500° per second (approximately 700 ml per hour). This value is also limited to less than the requested speed to maintain the requested flow rate in the case where the 2990 peristaltic pump is only delivering 80 uls per stroke. This would be an underfill and likely the result of some problem upstream of the 2990 peristaltic pump. Velocity is calculated using current volume delivered, requested volume delivered, previous stroke volume, and requested flow rate as depicted in Figure 327. A = Stroke Volume at the end of the previous stroke B = Measured Delivered Volume from the previous stroke D = Expected Stroke Volume C = B + D - AT = Requested Trajectory Flow Rate C = T(t)

[0001036] In order to achieve a consistent flow rate, particularly during low flow rate deliveries, the rate at which plunger 3091 descends needs to be controlled. The goal is to keep the flow as continuous and as close to the trajectory volume as possible. This is complicated by periods when the 2990 peristaltic pump does not deliver (refills, pressurizes, etc.).

[0001037] To achieve continuous flow, at the beginning of the delivery stroke the volume delivered as part of the previous stroke should be equal to the trajectory volume. This ensures a smooth initial delivery (preventing an initial "acceleration" from reaching). In order to accomplish this, at the end of the previous stroke the peristaltic pump 2990 must have delivered in excess of the volume that is accumulated during the Refill and Pressurization phases 830, 835. This Surplus Delivery volume is applied throughout the stroke. delivery, so that at the beginning none of it is applied, but at the end the complete volume is added.

[0001038] An additional consideration is fill volume. Shown in Figure 328 is a graph of volume delivered versus cam angle at various fill volumes for various cycles. In the case of a completely filled pumping chamber (approximately 150 uls), there is a gush of fluid as outlet valve 3111 opens for the first time. Alternatively, in the case of fill volumes of less than about 130 uls, there is a tendency to draw fluid. Both of these occurrences negatively affect flow continuity. In order to mitigate this, in some embodiments a target fill volume is adjusted to minimize these effects.

[0001039] The graph in Figure 328 shows multiple delivery strokes, with the delivered volume normalized to 135 uls, most of the stroke is repeatable, adjusting once for the fill volume. The result of all this is a third order function that calculates a desirable cam axis angle 3080 given a requested volume. See below for pertinent equations. VARIABLES n = Current Delivery Stroke i = Current Motor Control ISR Cycle f(x) = 3rd Order Polynomial Fitting En = Expected Pulse Volume given a Fill Volume per current delivery stroke Pn = Pulse Volume per f (x) per delivery stroke (this is a constant) Sn = Lack of Expected Volume of current stroke Ti= Current Target Volume via Trajectory Vn-1 = Delivered Volume Measured completion of previous delivery stroke Qi = Volume- target to be Delivered at time i Fi: = Fraction of Stroke completed at time i On = High Volume (Trajectory volume increase during non-delivery portions of cycle) θi = Requested Cam Axis Angle θo = Cam Axis Angle initial at the beginning of the delivery course EQUATIONS Sn = Pn - En Qi = Ti — Vn-1

[0001040] In some embodiments, the speed of the engine 3072 during the delivery stroke is limited to no more than the Delivery Stroke Speed. The result of this is that at high speeds, the requested position is always ahead of the speed-limited position. At lower flow rates, the 3080 camshaft position quickly reaches the calculated position and subsequently follows the above algorithm.

DOWNSTREAM OCCLUSION DETECTION

[0001041] The controller can determine whether a downstream occlusion exists by comparing the pressures or forces measured at the occlusion detector 3535 (3068 in Figure 257) during the delivery period 840, during the previous refueling period 830, and data from pressure filtered from previous pump cycles. Here, a pump cycle is a complete revolution of the 3080 camshaft that produces a refueling, a pressurization, and a delivery period (830, 835, 840). A downstream occlusion will be determined to exist by the processor if an occlusion condition occurs. In some embodiments, the occlusion condition can be determined to exist using the equations described in the following paragraphs. The variables of the occlusion equations are as follows: f = low-pass filter constant, IPMIN = sum of changes in PMIN since therapy began, PMINi = minimum pressure while the outlet valve is closed during pump cycle i, PMAXi = maximum pressure while the outlet valve is open during cycle of pump i, ΔFPMINi = change in minimum pressure in cycle i less than the low-pass filtered change in minimum pressure, ΔPL = the minimum pressure of the first pump cycle minus the lowest pressure recorded during therapy, ΔPMINi = change in minimum pressure equal to the difference between the minimum pressure of pump cycle i (PMINi) and the minimum pressure of the previous pump cycle PMINi1, ΔP*MINi = step-filtered value -below the change in minimum pressure, ΔPPi = maximum change in pressure during a cycle, and ∑ΔPMIN = sum of the change in minimum pressure (ΔPMIN) from the start of therapy during the current cycle i.

[0001042] The pressures or forces measured by the 3545B sensor can be filtered with a low-pass filter to reject false noise. In one embodiment, the low-pass filter may reject noise above 1000 Hz. A graph of hypothetical filtered pressures over time is represented graphically in Figure 329, wherein the pressure oscillates between lower pressures 850 when the outlet valve 3111 (Figure 259) is closed and high pressures 851 when the outlet valve 3111 is open and flow is being forced through the infusion tube 3210 which is pressed against the pressure sensor 3535B. A downstream occlusion can create greater resistance to flow as fluid is pushed toward the patient, resulting in higher peak pressures and/or higher pressures when the 3111 outlet valve is closed as restricted fluid flows through a partial occlusion. .

[0001043] An exemplary embodiment of a downstream occlusion test compares ΔPMINi to a constant value, where ΔPMINi is the change in minimum pressure of sequential cycles that is equal to the difference between: (1) the minimum pressure of a pump cycle i (PMINi) and (2) the minimum pressure from the previous pump cycle PMINi-1. If ΔPMINi is greater than a predefined value, the processor may declare an occlusion. That is, the processor (e.g., the RTP 3500 of Figure 324) is configured to, using the pressure signal from pressure sensor 368 (see Figure 357), determine whether a downstream occlusion exists when a difference between a first plateau pressure level of a first cycle and a plateau pressure level of a second cycle is greater than a predetermined threshold. The pressure signal from the pressure sensor 368 can be filtered (analog or digital filtering) or unfiltered. The first and second cycles can be cycles sequential to each other. The terms "first" and "second" are not intended to indicate an order or precedence of the cycles, but these terms are used to indicate that there are two cycles used for determination. The pressure or volume data for each cycle can be indicated by a counter that increments with each pump cycle from 0 to n cycles. The current pump cycle is referred to as cycle i. In this document, the pressure, volume or other data value for a given cycle will be identified with a subscript so that PMINi is the minimum during cycle i. ΔPMINi is the difference between the current pump cycle minimum pressure (PMINi) and the previous pump cycle minimum pressure PMINi-1.

[0001044] Alternatively, the processor may declare a downstream occlusion for cycle i, if the step-down filtered value of the change in minimum pressure (ΔP*MINi) exceeds a given first threshold. The asterisk indicates that the series pressure data is low-pass filtered in the time domain. The low-pass filtered value of change in minimum pressure (plateau-to-plateau pressure) is calculated by adding a weighted value of the new change in minimum pressure (ΔP*MINi) to a weighted value of the previous filtered value of the change in pressure minimum ΔP*MINi-1):

[0001045] where f is the weighting value for the newest data. In one example, the weighting value for f is 0.05. The first sample of filtered pressure data ΔP*MINi can be set to ΔPMINi (where i = 1, 2, 3, etc.). In another embodiment, the following equation is used to perform low-pass filtering:

[0001046] In another embodiment, the processor may declare an occlusion downstream for cycle i, if the difference between the current change in minimum pressure (ΔPMINi) and the low-pass filtered change in minimum pressure (Δ*PMINi) is greater than a given second threshold. The difference between the current change in minimum pressure and the low-pass filtered change in minimum pressure is calculated as: ΔFPMINi = ΔPMINi - Δ*PMINi: That is, the processor (for example, the RTP 3500 in Figure 324) is configured to, using the pressure signal from pressure sensor 368 (see Figure 357), determine whether a downstream occlusion exists when a difference is greater than a predetermined threshold, wherein the difference is a subtraction of: (1) a filtered value of a sequential series of sequential plateau-to-plateau pressure values of the plurality of cycles from (2) a plateau-to-plateau value. The pressure signal from the pressure sensor 368 can be filtered (analog or digital filtering) or unfiltered.

[0001047] In another embodiment, a downstream occlusion is declared when the sum of changes in minimum pressure (change from cycle to cycle) exceeds a given third threshold, wherein the sum of changes in PMIN (IPMIN) is calculated by the sum of all changes in the minimum pressures at the start of therapy, the addition of the difference between the minimum pressure of the first pump cycle (PMIN0) and the minimum pressure recorded during current therapy:

[0001048] where ΔPL is the initial pressure minus the lowest recorded pressure. If IPMIN exceeds a third given value, then the controller may declare an occlusion. That is, the processor (e.g., the RTP 3500 of Figure 324) is configured to, using the pressure signal from pressure sensor 368 (see Figure 357), determine whether a downstream occlusion exists when a sum of each sequential plateau-to-plateau pressure value of the plurality of cycles is greater than a predetermined threshold. The processor (e.g., the RTP 3500 of Figure 324) may perform this test, in some specific embodiments, by comparing the current minimum pressure of the current cycle to the lowest monitored minimum pressure of all previous cycles. For example, the processor (e.g., the RTP 3500 of Figure 324) may be configured to, using the pressure signal from pressure sensor 368 (see Figure 357), determine whether a downstream occlusion exists when a plateau of a cycle of the plurality of cycles is greater than a lowest plateau among all cycles of the plurality of cycles by a predetermined amount. The pressure signal from the pressure sensor 368 can be filtered (analog or digital filtering) or unfiltered.

[0001049] A fourth example of a downstream occlusion test evaluates the maximum change in pressure during a cycle (ΔPPi) by subtracting the minimum pressure of the current cycle (PMINi) from the maximum pressure of the same cycle (PMINi): ΔPP i = PMAX i - PMIN i-1

[0001050] where PMAXi is the maximum pressure during delivery period 840. The controller may declare a downstream occlusion if the maximum change in pressure during a cycle (ΔPPi) exceeds a fourth given threshold. That is, the processor (e.g., the RTP 3500 of Figure 324) is configured to, using the pressure signal from pressure sensor 368 (see Figure 357), determine whether a downstream occlusion exists when a difference between a peak pressure level and a plateau pressure level is greater than a predetermined threshold in one cycle of the plurality of cycles. The pressure signal from the pressure sensor 368 can be filtered (analog or digital filtering) or unfiltered. In the event of a downstream occlusion, the controller can command the pump to reverse flow fluid through the peristaltic pump 2990 to relieve pressure on the occlusion. It may be beneficial to relieve pressure on the occlusion to prevent a bolus of fluid from being directed toward the patient when the occlusion is relieved. In one example, the occlusion can be released by unclamping or kinking the infusion tube 3210 between the peristaltic pump 2990 and the patient.

UPWARD OCCLUSION/INLINE AIR MEASUREMENT

[0001051] The controller can detect an upstream occlusion or determine the volume of air pumped towards the patient based on the measured volume per stroke and historical volume per stroke average. The controller calculates an insufficient delivery volume for each VUD stroke i as:

[0001052] Where fv is a weighting factor for the volume and Vi is the volume of fluid pumped during cycle i. In other additional embodiments, the controller calculates Vavgi as follows:

[0001053] The controller maintains a temporary store of multiple VUDs, discarding the oldest as the newest VUD is added. If the 3545 in-line air detector (3066 in Figure 257) detects a bubble, the controller will assume that the VUD i represents an air bubble. If the 3545 in-line air detector does not detect air, then VUD i is assumed to be insufficiently delivered volume. The controller may declare an upstream occlusion, if the VUD i is greater than a given value, the 3545 in-line air detector does not detect air. The controller may determine the volume of air pumped toward the patient and may signal an alert if the volume of air exceeds a first value in a first period of time and issue an alarm if the volume of air exceeds a second value in a second period of time. time. In one example, the controller calculates the air bubble volume (VBUBBLE) by summing the insufficiently delivered volumes (VUD i) for each stroke when the in-line air detector 3545 signals the presence of air and some number of VUD i before of the first air detection: VBUBBLE = ∑VUD i.

[0001054] In one example, VBUBBLE is calculated for each course when the in-line air detector 3545 signals the presence of air and the three VUD i before the first air detection.

[0001055] In an alternative embodiment, the controller calculates an insufficiently delivered volume for each course VUD i as: VUD i = VT - Vi

[0001056] where VT is the nominal volume of a pump cycle that is stored in the controller. In this alternative modality, the controller calculates the total volume of the air bubble (VBUBBLE) by adding the insufficiently delivered volumes (VUD i) for each stroke when the in-line air detector 3545 signals the presence of air and some number of VUD i before the first air detection: VBUBBLE = ∑(VUD i — V*UD i) V*UD i = fv * V*UD i + (1-fv) * V*UDi-1

[0001057] where V*UDi is the filtered value of VUD and fv is the weighting average. In another embodiment, V*UDi is calculated as follows:

[0001058] In one example, the VBUBBLE is calculated for each stroke when the in-line air detector 3545 signals the presence of air and the three VUDi before the first air detection. In one embodiment, each VBUBBLE blob volume is added to a temporary storage of blob volumes that covers an adjusted period of time, and the sum of the blob volumes in the temporary storage are evaluated against a standard. If the sum of the bubble volumes exceeds a given threshold, then the controller issues an alarm for air in line (i.e., air in the pipe). The controller can reverse the 2990 peristaltic pump to draw air back into the patient. In one example, temporary storage captures the most recent 15 minutes of operation and the air volume threshold is set to a value between 50 and 1,000 microliters. In one example, bubble volumes smaller than a given value can be counted in the bubble volume sum. In one example, bubble volumes less than 10 microliters can be ignored. The air volume threshold may be adjustable per user or may be part of the DERS data that is downloaded from the device server communications port. The DERS and device server communication port are described in detail in the non-provisional cross-reference application for SYSTEM, METHOD, AND APPARATUS FOR ELECTRONIC PATIENT CARE (Legal Registration No. J85).

LEAK TEST

[0001059] A leak is determined at the end of the pressurization period 835 by monitoring the position of the plunger 3091 while the L-shaped plunger cam follower 3090 is not resting on the plunger cam 3083 and the plunger tip 3091B is resting in the infusion tube 3210. If the plunger 3091 moves more than a given amount in a given time, indicating that it has leaked past the valves 3101, 3111. In one embodiment, the peristaltic pump 2990 is stopped for half a second every six seconds in the end of pressurization period 835 to monitor the position of plunger 3091 to determine whether a leak exists between valves 3101, 3111.

STATE DIAGRAM FOR FLUID DELIVERY BY THE PERISTALTIC PUMP

[0001060] The state diagram for the software that controls fluid delivery is depicted in Figure 330. The Maximum Delivery State (capitalized phrases herein may refer to variables, processes or data structures, etc. depending on the context ) is the Super State for the entire 3430 pump controller and comprises the Idle State and the Running State. The Idle State is entered upon initiation of the 3430 pump controller, completing a delivery, or stopping/aborting a delivery. The Running State is the Super State for all states involving the 3072 engine or making a delivery. The Running State also administers Freeze commands.

[0001061] The Delivery State is the Super-State for all states that involve making a delivery. This state manages Stop commands, which had two behaviors that depend on the current state. If commanded during an active delivery, the 2990 peristaltic pump will terminate delivery after the current stroke is completed. If the 2990 peristaltic pump is currently in the frozen state, it will immediately terminate delivery.

[0001062] Delivery Start State means the beginning of a delivery cycle or a rotation of the camshaft 3080. The peristaltic pump 2990 will transition to one of three states depending on current conditions. If enough time has elapsed since the last leak check, the Moving to Leak Check Position State is called. If the previous delivery was frozen and aborted mid-stroke, enter the Moving to Plunger Down State to resume delivery where the previous delivery ended. Otherwise, the 3430 motor controller transitions to the Moving to Pressurized Position State.

[0001063] The Moving to Leak Check Position State commands the 3430 motor controller to move to and hold the Closed Valves Plunger Down Position position. The speed of the 3072 motor is commanded to move at 800° per second. Upon receipt of notification that the 3080 camshaft has reached the desired position, the Pressurized Position Measurement is taken for volume calculations and the Leak Check Hold State is called.

[0001064] The Leak Check Wait State is inactive until a set amount of time has elapsed, allowing the infusion tube 3210 to settle and, in the event of a leak, fluid to escape the pumping chamber. Once the time has elapsed, the position of the 3091 plunger is measured again and compared to the Pressurized Position in order to determine the presence of a leak condition. The Fault Detector is told that the delivery stroke is beginning in order to monitor air and occlusions and the Plunger Down Position Movement State is called.

[0001065] The Moving to Pressurized Position State commands the 3430 motor controller to move in direction and send a notification upon reaching the Closed Valves Plunger Down Position. It will continue to move upon reaching this position until a new command is issued. The speed of the 3072 motor is commanded to move at 800° per second.

[0001066] Upon receiving notification that the cam shaft 3080 has reached the desired position, the Pressurized Position Measurement is taken for volume calculations and the Plunger Down Position Movement State is called. The Fault Detector is said to be on delivery in order to monitor air and occlusions.

[0001067] The Plunger Down Position Movement State controls the position of cam shaft 3080 throughout the entire portion of the rotation of cam shaft 3080 that the output valve 3111 is open. The 3080 camshaft position is controlled in a way to try to keep the flow as consistent as possible. During this state, the speed of the 3072 engine is again limited to no more than the calculated Delivery Stroke Speed. There are two paths by which the 3430 motor controller can exit this state. In the first case, the State is notified once the camshaft 3080 reaches the Output Open Plunger Down Position. Alternatively, if the total delivery volume reaches the commanded volume during the stroke, the camshaft position 3080 is frozen and the State is notified that the course is complete.

[0001068] Upon notification that cam shaft 3080 has reached the Output Open Plunger Down Position, the position of the plunger 3091 is stored as the Post Delivery Position Measurement and the Fault Detector is told that the delivery stroke is complete. Using this measurement, the volume delivered is calculated (using the calibration in Section 3). If the 2990 peristaltic pump has been stopped mid-stroke, the delivered volume is estimated using the current position and fill volume. Using the updated delivery volume information, the updated Delivery Stroke Speed is calculated. Finally, in the event that the delivery volume has been reached, the peristaltic pump 2990 calls the End of Delivery State. Otherwise, you enter the Moving to Fill Position State.

[0001069] The Moving to Fill Position State commands the 3430 motor controller to move in direction and send a notification upon reaching the Inlet Valve Open Plunger Up Position (minus Prefill Window). It will continue to move upon reaching this position until a new command is issued. The speed of the 3072 engine is commanded to move at the calculated Delivery Stroke Speed. Once the desired position is reached, the Moving State by Fill Position is called.

[0001070] The Moving to Fill Position State commands the 3430 motor controller to move in direction and send a notification upon reaching the Inlet Valve Open Plunger Up Position (plus the Back Fill Window). It will continue to move upon reaching this position until a new command is issued. The 3072 motor speed is commanded to move at the calculated Fill Stroke Speed (see Section 8.3). The Fill Stroke Speed is calculated upon entering this state before issuing a new 3072 motor command. Once the desired position is reached, the End of Delivery State is called.

[0001071] The End of Delivery Status checks whether the delivery volume has been achieved or a stop has been requested. If this is the case, the 3430 engine controller enters the Idle State and the 3080 camshaft position is commanded to go to the Inlet Valve Open Plunger Up Position. Otherwise, the Delivery Start State is called and a new delivery cycle begins.

[0001072] The Freeze State is called when the Executing State processes a freeze command. The 3080 camshaft position is frozen at its current position and the Fault Detector and Volume Estimator are notified that the delivery is frozen.

[0001073] If a Resume Delivery command is received while in the Freeze State, the State machine is returned to the State it was in before entering the Freeze State. The Failure Detector and Volume Estimator are both informed that delivery is resuming. If a Stop Delivery Command is received, the Idle State is called.

[0001074] The Calibration State is the Super-State for the states involved in calibrating the positions of the cam shaft 3080 and the piston 3091.

[0001075] The Start Search State performs the 3080 cam axis calibration. Entering this state, the IO Access class is notified that a calibration is beginning, so certain sensor protections can be turned off. The State receives notification once the process is complete. Upon receiving this notification, the calibration values are sent to non-volatile memory. Finally, the Moving to Home State is called.

[0001076] The Moving Home State simply commands the 2990 peristaltic pump to move to the Inlet Valve Open Plunger Up Position. Upon reaching this position, the 2990 peristaltic pump returns to the Inactive State.

[0001077] Figure 331 illustrates a possible state chart of the code for detecting a failure of the peristaltic pump 2990 and Figure 332 illustrates an occlusion detection state chart for detecting an occlusion of the peristaltic pump 2990 in accordance with an embodiment of the present description. Figure 33 shows a feedback control loop for speed controlling the motor 3072 of peristaltic pump 2990 in a peristaltic pump 2990 in accordance with an embodiment of the present disclosure.

SOFTWARE ARCHITECTURE

[0001078] The software architecture of the peristaltic pump 2990 is shown schematically in Figure 334. The software architecture divides the software into cooperating subsystems that interact to perform the requested pumping action. The software may be equally applicable to all embodiments described herein. The software can also be used for other pump types that may not be described in this document. Each subsystem can be composed of one or more execution streams controlled by the underlying operating system. Useful terms used in the art include operating system, subsystem, process, thread, and task.

[0001079] Asynchronous messages 4130 are used to "push" information to the target task or process. The sender process or task does not receive message delivery confirmation. Data delivered in this manner is typically repetitive in nature. If messages are expected on a consistent schedule, the receiving process or task can detect a failure if a message does not arrive on time.

[0001080] Synchronous messages 4120 can be used to send a command to a task or process or to request (pull) information from a process or task. After sending the command (or request), the originating process or task suspends execution while waiting for a response. The response may contain the requested information or may simply confirm receipt of the message sent. If a response is not received in a timely manner, the sending process or task may time out. In such an event, the sending process or task may resume execution and/or may signal an error condition.

[0001081] An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system acts as an intermediary between programs and computer hardware. Although some application code is executed directly by hardware, application code can often make a system call to or be interrupted by an OS function.

[0001082] The RTP 3500 operates on a Real-Time Operating System (RTOS) that has been certified to a level of security for medical devices. An RTOS is a multitasking operating system that aims to run applications in real time. Real-time operating systems often utilize specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The UIP 3600 runs on a Linux operating system. The Linux operating system is a Unix-like computer operating system.

[0001083] A subsystem is a collection of software (and perhaps hardware) assigned to a specific set of (related) system functionality. A subsystem has clearly defined responsibilities and a clearly defined interface to other subsystems. A subsystem is an architectural division of software that uses one or more processes, threads, or tasks.

[0001084] A process is an independent executable that runs on a Linux operating system that runs in its own virtual address space. Memory management hardware in the CPU can be used to enforce the integrity of memory isolation by writing space protection code and disabling access to data outside the process memory region. Processes can only pass data to other processes using interprocess communication facilities.

[0001085] In Linux, a thread is a separately scheduled concurrent path of program execution. In Linux, a thread is always associated with a process (which must have at least one thread and can have multiple threads). Threads share the same memory space as their "parent" process. Data can be directly shared among all threads belonging to a process, but needs to be removed to properly synchronize access to shared items. Each thread has an assigned execution priority.

[0001086] A task in an RTOS (Real-Time Operating System) is a separately scheduled concurrent path of program execution, analogous to a Linux "thread". All tasks share the same memory address space which consists of the entire CPU memory map. When using an RTOS that provides memory protection, each task's effective memory map is restricted by the Memory Protection Unit (MPU) hardware to the common code space and the task's private stack and data space.

[0001087] Processes in the UIP 3600 communicate via IPC calls as shown by the one-way arrows in Figure 334. Each solid line arrow represents a synchronous message call and response 4120 and the dotted line arrows are asynchronous messages 4130. Tasks in RTP 3500 communicate in a similar way with each other. The RTP 3500 and the UIP 3600 are linked by an asynchronous serial line 3601, with one of an InterComm Process 4110 or InterComm Task 4210 on each side. The InterComm 4110 Process features the same communication API (Application Programming Interface) on both sides of the connection, so all processes and tasks can use the same method calls to interact.

[0001088] Referring now also to Figure 324, the RTP 3500 receives data from the Hall sensors 3436 (i.e., rotation sensors) and the UI 3600 receives data from the encoder 3438 (i.e., a counter). The RTP 3500 and the UI 3600 are in operative communication with each other and are configured to determine whether the monitored plurality of pulses determined by the RTP 3500 correspond to the counted pulses as received by the UI processor 3600 from the encoder 3438. This can be done by determining whether they correspond to a predetermined quantity, such as a percentage quantity, a predetermined number of pulses, a predetermined angular value and/or a predetermined number of degrees of rotation by the motor.

[0001089] In another embodiment, the RTP 3500 and the UI 3600 each estimate a quantity of pumped fluid and determine whether the estimated volumes of pumped fluid are within a predetermined range relative to each other. This can be done by determining whether they correspond to a predetermined range, such as a percentage amount.

[0001090] Executive Process 4320 can be invoked by Linux system startup scripts after all operating system services have started. The Executive Process 4320 can then start the various executable files that comprise the software on the UIP 3600. If any of the software components exit or fail unexpectedly, the Executive Process 4320 can be notified and can generate the appropriate alarm.

[0001091] While the system is running, Executive Process 4320 can act as a software "supervision" for various system components. After registering with the Executive process 4320, a process may be requested to "check" or send a signal periodically to the executive process 4320. Failure to "check" at the requested interval may be detected by the Executive Process 4320. Upon detection of a subsystem with failure, Executive Process 4320 can take corrective action by: either doing nothing, or declaring an alarm, or restarting the failed process. The corrective action taken may be predetermined by a table entry compiled in Executive Process 4320. The "check" interval may vary from process to process based in part on the importance of the process. The check interval may also vary during operation of the 2990 peristaltic pump to optimize the response of the 4256 pump controller while minimizing computer processes. In an exemplary embodiment, during pipe loading, the pump controller 4256 may check less frequently than during active pumping.

[0001092] In response to the requested verification message, Executive Process 4320 may return various system status items to processes that have been verified. System status items can be the status of one or more components in the pump and/or errors. System status items may include: battery status, WiFi connection status, device communication port connection status, device status (Idle, Infusion in Progress, Diagnostic Mode, Error, etc.), technical error and engineering log levels.

[0001093] A thread running in Executive Process 4320 can be used to read the State of battery 3420 from an internal monitor chip on battery 3420. This can be done at a relatively infrequent interval such as every 10 seconds.

[0001094] UI View 4330 may implement graphical user interface (GUI), rendering display graphics on display screen 3725 and responding to inputs on touch screen 3735 or other data input means. The 4330 UI Vista project can be stateless. The screen being displayed can be driven by the UI Template 4340 process, along with any variable data to be displayed. The controlled display is updated periodically regardless of data changes.

[0001095] The style and appearance of user input dialogs (Virtual Keyboard, drop-down selection list, check box, etc.) can be specified by screen design and fully implemented by UI View 4330. User input can be collected by UI View 4330 and sent by UI Template 4340 for interpretation. The UI Vista 4330 can provide multi-region, multi-language support with facilities for the following list which includes, but is not limited to: virtual keyboards, unicode strings, loadable fonts, left-to-right input, translation facilities loadable translation) and loadable number and date formats.

[0001096] UI Model 4340 can implement screen flows and thus control the user experience. The US Model 4340 can interact with the UI View 4330, specifying the screen to display and supplying any transient values to be displayed on the screen. Here, the screen refers to the image displayed on the physical display screen 3725 and the interactive areas or user dialogs, i.e., buttons, sliders, numeric keypads, etc., on the touch screen 3735. The UI Model 4340 can interpret any user input sent from the UI View 4330 and can either update the values on the current screen, command a new screen, or pass the request to the appropriate system service (i.e. "start pumping" is passed to the RTP 3500).

[0001097] During selection of a medication for infusion from the Drug Delivery Library, the UI Model 4340 may interact with the Drug Delivery Library stored in the local database that may be part of the Database System 4350. User selections can adjust run time settings to program and administer the desired medication.

[0001098] Although the operator may be inputting an infusion program, the UI Template 4340 relays user input values to the Infusion Manager 4360 for validation and interpretation. Therapeutic decisions may not be made by UI Template 4340. Treatment values may be passed from Infusion Manager 4360 to UI Template 4340 to UI View 4330 for display to the user.

[0001099] The UI Model 4340 can continuously monitor device status collected from the Infusion Manager 4360 (current infusion progress, alerts, port sensor 3163 and slide clamp sensor 3152, etc.) for possible display by View of UI 4330. Alerts/Alarms and other changes in system state may cause a screen change by UI Model 4340.

ADDITIONAL DOSING SAFETY SOFTWARE ALGORITHM(S)

[0001100] The 4360 Infusion Manager (IM) Process can validate and control the infusion delivered by the 2990 peristaltic pump. To start an infusion, the user can interact with the 4330/4340 View/UI Template to select a medication and usage specific clinic. This specification can select a specific Drug Administration Library (DAL) entry for use. The IM 4360 can load this DAL entry from the 4350 database for use in validation and infusion operation.

[0001101] Once a Drug Administration Library entry is selected, the IM 4340 can pass the dose mode, limits for all parameters that can be entered per user, and default values (if set) for the UI Template 4340. Using this data, UI Template 4340 can guide the user when entering the infusion program.

[0001102] As each parameter is entered by the user, the value can be sent from the UI View/Model 4330/4340 to the IM 4360 for verification. The IM 4360 can echo parameters back to the 4330/4340 View/UI Model, along with an indication of the parameter's compliance with the DAL limits. This may allow the Vista/UI Template 4330/4340 to notify the user of any value that is out of bounds.

[0001103] When a full set of valid parameters have been entered, the IM 4360 can also return a valid infusion indicator, allowing the 4330/4340 UI View/Template to present a "home" control to the user.

[0001104] The IM 4360 can simultaneously make the infusion/pump status available to the Vista/UI Model 4330/4340 upon request. If the View/UI Model 4330/4340 is displaying a "situation" screen, it may request this data to complete the screen. The data can be a composite of the infusion state and the pump state.

[0001105] When asked to put a (valid) infusion into operation, the IM 4360 can pass the "Infusion Spreadsheet" which contains user-specified data and the "Infusion Template" which contains the read-only limits of the DAL as a CRC binary block for the 4220 Infusion Control Task running on the RTP 3500. The 4220 Infusion Control Task on the RTP 3500 can receive the same user inputs, conversions, and DERS inputs and recalculate the Infusion Spreadsheet. Results calculated by the Infusion Control Task 4220 can be stored in a second CRC binary block and compared to the first binary block of the UIP 3600. Infusion calculations performed on the UIP 3600 can be recalculated and double-checked on the RTP 3500 before the infusion is running.

[0001106] Coefficients for converting input values (i.e. 1, grams, %) to a standard unit such as ml can be stored in the memory of the UIP 3600 or in the database system 4350. The coefficients can be stored in a lookup table or in specific memory locations. The lookup table can contain dozens of conversion values. In order to reduce the chance that flipping a single bit will result in the wrong conversion factor being used, the addresses for the conversion values can be distributed among the values zero through 4294967296 or 232. The addresses can be selected so that the binary form of one of the addresses is never just one bit different from a second address.

[0001107] While an infusion is running, the IM 4360 can monitor its progress, sequences, pauses, restarts, secondary infusions, bolus and KVO (keep vein open) situations as needed. Any user alert requested during infusion (Infusion almost complete, KVO callback, secondary complete callback, etc.) can be tracked and triggered by the IM 4360.

[0001108] Processes on the UIP 3600 can communicate with each other through a proprietary messaging scheme based on a message queue library that is available with Linux. The system can provide both acknowledgment (synchronous message 4120) and non-acknowledgment (asynchronous message 4130) message passing.

[0001109] Messages destined for the Real-Time Processor (RTP) 3500 may be passed to the InterComm Process 4310 which may forward the messages to the RTP 3500 on a serial link 3601. A similar InterComm Task 4210 on the RTP 3500 may relay message 15 to its intended destination via the RTP 3500 messaging system.

[0001110] The messaging scheme used in this serial link 3601 can provide error detection and retransmission of failed messages. This may be necessary to allow the system to be less susceptible to electrical disturbances that can occasionally "garble" communications between processors.

[0001111] To maintain a consistent interface throughout all tasks, the message contents used with the messaging system may be data classes derived from a base class (Message Base). This class adds data identity (message type) and data integrity (CRC) to messages.

[0001112] The Audio Server Process 4370 can be used to render sounds on the system. All user feedback sounds (key press beeps) and alarm or alert tones can be produced by playing back previously recorded sound files. The sound system can also be used to play music or speech if desired.

[0001113] Sound requests can be symbolic (such as "Play High Priority Alarm Sound"), with actual sound file selection built into the 4370 Audio Server Process. The ability to switch to an alternate sound environment can be provided. This ability can be used to standardize sounds for regional or linguistic differences.

[0001114] The Device Communication Port Manager Process (DGCM) 4380 can manage communications with the Device Communication Port Server on a WiFi network 3620, 3622, 3720. The DGCM 4380 can be started and monitored by the Executive Process 4320. If the DGCM 4380 exits unexpectedly, it can be restarted by the Executive Process 4320, however if the failures are persistent, the system can continue to operate without the communication port being in operation.

[0001115] It may be the function of the DGCM 4380 to establish and maintain the WiFi connection and then establish a connection to the Device Communication Port. All interactions between the DGCM 4380 and the Device Communication Port may be a system such as the system described in the non-provisional cross-reference application for System, Method, and Apparatus for Electronic Patient Care (Legal Registration Number J85).

[0001116] If the connection to the communication port is unavailable or becomes unavailable, the DGCM 4380 may discontinue any transfer in progress and attempt to reconnect the link. Transfers can be resumed when the link is reestablished. Network and Port operational states may be periodically reported to Executive Process 4320. Executive Process 4320 may distribute this information to display to the user.

[0001117] The DGCM 4380 can function as a stand-alone subsystem, polling the Device Communications Port Server for updates and downloading newer items when available. Additionally, the DGCM 4380 can monitor log tables in the database, updating new log events as they become available. Events that are successfully uploaded can be flagged as such in the database. After a reconnection to the Device Communication Port Server, the DGCM 4380 can "catch up" with log upload transfers, sending all items that were inserted during the communication interruption. Firmware and Drug Delivery Library updates received from the Communication Port can be staged in the UIP 3600 file system for subsequent installation. Infusion programs, clinical recommendations, patient identification and other data items intended for the device can be prepared in the database.

[0001118] The DGCM 4380 can report connection status and date/time updates to the Executive Process 4320. There can be no other direct connections between the DGCM 4380 and any of the other optional software. Such a design decouples the operational software from the potentially transient availability of the Device Communication Port and the WiFi network.

[0001119] Motor Verification software 4383 reads a hardware encoder or counter 3438 (Figure 325) that reports the rotation of the motor 3072. The software in this module independently estimates the movements of the motor 3072 and compares them to the expected movement based on in the user inputs for the infusion rate. This is an independent check for proper engine control. However, prime mover control software can run on the RTP 3500.

[0001120] Event information may be written to a register via Registration Process 4386 during normal operation. These events can consist of internal machine measurements and status, as well as therapy history events. Due to the volume and frequency of event logging data, these logging operations may be temporarily stored in a FIFO queue while waiting to be written to the database.

[0001121] An SQL database (PostgreSQL) can be used to store record data from the Drug Administration Library, Local Machine Settings, Infusion History and Machine. Stored procedures executed by the database server can be used to isolate the application from internal database structures.

[0001122] The 4350 database system can be used as a temporary storage for log data destined for the Device Communications Port Server, as well as a staging area for infusion adjustments and warnings sent to the pump from of the Communication Port.

[0001123] Upon request to start an infusion, the DAL input and all user-selected parameters can be sent to the Infusion Control Task 4220. All DAL validations and a recalculation of the infusion rate and volume with based on the requested dose can be performed. The result can be checked against the results calculated by the IM 4360 on the UIP 3600. These results can be required to match to continue.

[0001124] During the operation of an infusion, the Infusion Control Task 4220 may control the delivery of each infusion "segment"; that is, where a part of an infusion consists of a volume and a rate. Examples of segments are: a primary infusion, KVO, bolus, remainder of primary infusion after bolus, primary infusion after titration, etc. Infusion segments are sequenced by IM Process 4360 on the UIP 3600.

[0001125] The Pump Control Task 4250 may incorporate controllers that drive the pumping mechanism. The desired pumping rate and quantity (VTBI) can be specified in commands sent by the 4220 Infusion Control Task.

[0001126] Pump Control 4250 may receive periodic sensor readings from Sensor Task 4264. The new sensor readings may be used to determine the speed and position of motor 3072 and to calculate the desired command to send to Motor Control Brushless IRQ 4262. Receiving the sensor message may trigger a recalculation of the controller output.

[0001127] While pumping fluid, the 4250 Pump Control Task may perform at least one of the following tasks: control pumping speed, measure volume delivered, measure detected air (in an ongoing time window), measure fluid pressure or other indications of occlusions and detect occlusions upstream.

[0001128] Relevant measurements may be reported to RTP Status Task 4230 periodically. The 4250 Pump Control can run one infusion segment at a time, stopping when the commanded delivery volume has been reached. Sensor Task 4264 can read and aggregate sensor data used for dynamic control of the pumping system. The sensor data may include the rotary encoder 3130 measuring the cam shaft, the linear encoders 3520, 3525 measuring the position of the plunger 3091.

[0001129] Sensor task 4264 can be scheduled to go live at a consistent rate of 1 kHz (every 1.0 ms) via a dedicated counter/timer. After all relevant sensors have been read, the data can be passed to the Pump Control Task 4250 via an asynchronous message 4120. Periodic receipt of this message can be used as the primary time base for synchronizing the control loops. of the 2990 peristaltic pump.

[0001130] The RTP Status Task 4230 may be the central repository for both the State and status of the various tasks running on the RTP 3500. The RTP Status Task 4230 may distribute this information to both the running IM 4360 on the UIP 3600, as well as for tasks on the RTP 3500 itself.

[0001131] The RTP Status Task 4230 can also be loaded with fluid from the infusion in progress. Pump starts and stops, as well as pumping progress, may be reported to the RTP Status 4230 by the Pump Control Task 4256. The RTP Status Task 4230 may account for at least one of the following: total volume introduced, primary volume delivered, primary VTBI (counted), volume delivered and VTBI of a bolus while the bolus is in progress, and volume delivered and VTBI of a secondary infusion while the secondary infusion is in progress.

[0001132] All alerts or alarms that originate in the RTP 3500 can be funneled through the RTP Situation Task 4230 and subsequently passed to the UIP 3600.

[0001133] While the unit is in operation, program flash memory and RAM memory can be continuously tested by the Memory Check Task 4240. This non-destructive testing can be scheduled so that the entire memory space on the RTP 3500 is tested accordingly. a few hours in a few hours. Additional periodic checks can be scheduled in this task if necessary.

[0001134] Tasks running on the RTP 3500 may be required to communicate with each other as well as with tasks running on the UIP 3600.

[0001135] The RTP messaging system can utilize a global addressing scheme to allow messages to be passed to any task in the system. Local messages may be passed in memory using the RTOS message passing facilities, with off-chip messages routed on the communications link (asynchronous serial 3601) by the InterComm Task 4210.

[0001136] The InterComm Task 4210 may manage the RTP 3500 side of the serial link 3601 between the two processors. It is the equivalent of the RTP 3500 of the InterComm Process 4310 on the UIP 3600. Messages received from the UIP 3600 can be relayed to their destination on the RTP 3500. Out-of-bounds messages can be forwarded to the InterComm Process 4310 on the UIP 3600.

[0001137] All messages between the RTP 3500 and the UIP 3600 can be checked for data corruption using an error detection code (32-bit CRC). Messages sent over the 3601 serial link can be resent if corruption is detected. This provides a communication system that can be reasonably ESD tolerant. Corrupt messages within the processor between processes can be managed as a hard system failure. All message content used with the messaging system can be data classes delivered from a common base class (Message Base) to ensure consistency across all possible message destinations.

[0001138] 4262 Brushless Motor Control may not function as a task; can be deployed as a process and strict foreground (context). Interrupts can be generated from the 3436 Hall effect switch or sensors and the switching algorithm can be put into operation entirely in the service interrupt routine.

[0001139] Figures 335 and 336 illustrate the geometry of two dual-band antennas that can be used with the peristaltic pump 2990 according to an embodiment of the present description. Figures 335 show a top and bottom view of the antenna, which can be manufactured using metallic layers on a substrate, as is typically done during the manufacture of a printed circuit board. Figure 336 can also be manufactured using a printed circuit board manufacturing method.

[0001140] Figure 337 shows a state diagram illustrating a method 5065 for providing surveillance functionality in accordance with an embodiment of the present description. Method 5065 is shown as a state diagram and includes states 5067, 5069, 5099, 5072, 5075, 5077, and 5079, and transition conditions 5066, 5068, 5070, 5071, 5073, 5074, 5076, 5078, 5080 and 5081.

[0001141] Method 5065 may be implemented by software, hardware, running software, or some combination thereof (e.g., as a hardware surveillance system). Method 5065 may be deployed by surveillance 3460 of Figure 324 so that it provides a motor activation signal to motor controller 3431. Figures 338A to 338F show a specific embodiment of a system that implements method 5065 of Figure 337.

[0001142] Refer now to Figures 337 and 338A to 338F. When power is supplied to the surveillance system (e.g., system 5003), method 5065 transitions 5066 to the off state of the surveillance system 5067 in which the engine enable signal is off (e.g., line 5015), the alarm is turned off (e.g. line 5016), and the timer is in an unknown state. The timer may be part of the surveillance IC 5012. The surveillance IC 5012 is a window surveillance. The 5003 system also includes I2C control lines 5013 (however, other control lines may be used) that interface with an I/O expander 5004 (or other hardware tongues). The I2C control lines 5013 may be part of the connections from the RTP 3500 to the surveillance 3460 of Figure 324. Additionally, a clean surveillance signal (line 5014 of Figure 338) may also be received from the RTP 3500 to the surveillance 3460. That is, the clean surveillance signal 5014 "strokes" the surveillance IC 5012.

[0001143] In transition 5068, the RTP 3500 (see Figure 324) clears the timer of the surveillance IC 5012 via the clear surveillance signal 5014 and the RTP 3500 enables the output of surveillance IC 5012 via the control lines I2C 5013 per instruction from I/O expander 5004 to enable a watchdog enable line 5018. This causes method 5065 to enter state 5069. In state 5069, the timer is initialized (set to zero), the enable line engine line 5015 is set to off and alarm line 5016 is set to off.

[0001144] The RTP 3500 enables motor power via the 5013 I2C control lines by setting the D flip-flop to true (using the preset pin of a 5005 D flip-flop) and pausing for 1 ms on the 5070 transition Method 5065 transitions to state 5099 in which the timer of the surveillance IC 5012 is running, the motor activation line 5015 is enabled, and the timer is less than 200 milliseconds. If the RTP 3500 sets the watch clear line 5014 when the watch is greater than 10 milliseconds and less than 200 milliseconds, the transition 5071 transitions the method 5065 to the state 5072 where the timer is reset. Method 5065 will transition back to state 5099.

[0001145] If the timer reaches 200 milliseconds or the timer is less than or equal to 10 milliseconds and the RTP 3500 sets the watch clear line 5014, transition 5074 transitions the method to state 5075. In state 5075, the watch IC 5012 sends a fault signal which is stored by a buffer 5009 which clears the D flip-flop 5005, thereby turning off the motor line 5015. In state 5075, the surveillance IC 5012 also sends the fault signal which is received by a NAND hold 5008 via an inverted input, which outputs a signal that is amplified by a buffer 5009 which clears a D flip-flop 5007 and thus turns on the alarm line 5016. The output of the D-dlip-flop 5007 is amplified by a load switch 5006.

[0001146] When the motor enable signal line 5015 is set to turn off the motor, the shutdown signal propagates through the non-inverting input of the NAND gate 5008 after about 1 millisecond, which causes transaction 5076 to stop. transaction to state 5077, thus allowing the alarm to be disabled. An I2C command may cause transaction 5080 to reset system 5003 back to state 5067.

[0001147] Otherwise, the alarm line 5016 will continue to alarm until a silence button 5017 is pressed, which is coupled to the preset of the D flip-flop 5007 to set the alarm line 5016 to off. That is, the button will cause transition 5078 to transition method 5065 to state 5079. An I2C signal via I2C control lines 5014 to IO expander 5004 may cause method 5065 to transition to state 5067.

[0001148] Figure 339 shows another embodiment of a peristaltic pump 5020 that has an L-shaped plunger in accordance with an embodiment of the present description. Pump 5020 may couple to a bar via clamp 5028. Pump 5020 includes a lever 5022 and a door 5100 that includes a cutout portion 5023. The cutout portion 5023 accommodates a shock absorber 5021.

[0001149] The pump 5020 also includes a touch screen 5024 coupled to the pump 5020 via an external periphery 5025. The external periphery 5025 includes an indicator light 5026. The indicator light 5026 may wrap completely around the touch screen touchscreen 5024. Indicator light 5026 may include a diffuser wrapped around touchscreen 5024 with a plurality of LED lights embedded therein (or optically coupled thereto). The 5026 indicator light may flash when the 5020 pump is running and/or may be a specific color when the pump is running (e.g., red, blue, green, yellow, etc.). The 5026 indicator light may be on continuously when the pump is not running or is in a standby state. Additionally, alternatively, or optionally, indicator light 5026 may be a specific color when the pump is not running or is in a standby state (e.g., red, blue, green, yellow, etc.).

[0001150] The pump 5020 may also include a gesture recognition device 5094, which may be a camera. A pump processor 5020 may be coupled to gesture recognition apparatus 5094 to receive user input from a gesture by a user. That is, the processor may be configured to present a user with at least one option via user interface 5024 and receive an option selected from the at least one option via gesture recognition apparatus 5094. The processor coupled to the interface user interface 5024 may be configured to provide a plurality of pump parameter inputs wherein each input of the plurality of pump parameter inputs is configured to receive a user-entered parameter. The processor may be configured to determine whether all user-entered parameters of all parameters of the plurality of pump parameters meet at least one predetermined safety criterion. Each entry of the plurality of pump parameter inputs may be present without another entry of the plurality of pump parameter inputs.

[0001151] The processor may be configured to provide a plurality of pump parameter inputs wherein each input of the plurality of pump parameter inputs is configured to receive a user-entered parameter. The processor may be configured to require that all inputs of the plurality of pump parameter inputs are entered within a predetermined amount of time. The processor may be configured to receive a user-entered parameter corresponding to the plurality of pump parameter inputs in any order.

[0001152] Figure 340 shows an exploded view of the peristaltic pump 5020 of Figure 339 in accordance with an embodiment of the present description. The pump 5020 includes an upper housing portion 5029 and a lower housing portion 5030. Additionally or alternatively, the upper portion 5029 and the lower portion 5030 of the housing 5029, 5030 may be formed unitarily in some specific embodiments. A pumping mechanism of module 5103 may be coupled to housing 5029, 5030. A motor 5101 drives the pumping mechanism of module 5103. The motor may be controlled via a circuit board 5102 that is coupled to the motor and various sensors , actuators, the 5024 touch screen, etc. Pump 5020 also includes cabling 5031 and a battery 5027 disposed behind touch screen 5024 (when mounted). Figure 341 shows a close-up view of the upper housing 5029, the lower housing 5030, and the power supply 5032. It is seen how the power supply is thermally coupled to the lower housing portion 5060 via the conductive path 5033.

[0001153] Pump 5020 includes power supply 5032. Power supply 5032 is coupled to a conductive path 5033 for housing 5030, 5029 (when assembled). The conductive path 5033 may be a piece of metal and may be formed unitarily with the housing 5030 (or 5029). The 5032 power supply can use the 5029, 5030 housing as a heat sink. The power supply 5032 may use any surface of the housing 5029, 5030 so that it is thermally coupled thereto and/or may be thermally coupled to the housing 5029, 5030 via the conductive path 5033.

[0001154] Figure 342A shows a front view of the pump display 5020 and Figure 342B shows a rear view of the pump display 5020 in accordance with an embodiment of the present description; On the back of the touch screen 5024 (see easily in Figure 342B) a near-field antenna 5034 is arranged. Figure 343 shows the sensor portion 5105 of the touch screen with the near-field antenna 5034 disposed adjacent to the rear side of the sensor portion 5105 of the touch screen 5024 (see Figures 342A to 342B). Shown is a frame 5035 that forms a metal loop with a gap 5104 that has a dielectric 5036 disposed within the gap 5104. The frame 5035 may be a sensor frame 5105 and/or the touch screen 5024. The antenna 5034 may be operate at 13.56 Megahertz and/or may be an NFC antenna. The metal frame 5035 together with the gap 5104 and the dielectric 5026 disposed within the gap can form a split ring resonator. The metal frame 5035 forms an inductor element of the split ring resonator and the gap 5014 with the dielectric 5036 disposed therein forms a capacitor element of the split ring resonator.

[0001155] Figure 344 shows an approximate side view of the pump 5020 which shows a rotation sensor 5037 for measuring the rotation of the cam shaft 5106 (which can be seen in Figure 345) in accordance with an embodiment of the present description. A magnet may be coupled to the cam shaft 345 so that the rotation sensor 5037 can measure the rotation of the cam shaft 5106. The rotation sensor 5037 may be a hall effect sensor. The rotation sensor 5037 can be coupled to the processor 3500 of Figure 324.

[0001156] Figure 345 shows an approximate side view of the pump 5020 with a plan cut in accordance with an embodiment of the present description. As the cam shaft 5106 rotates, the rotation sensor 5037 of Figure 344 senses the rotation of the cam shaft 5106. Rotation of the cam shaft 5106 causes the piston 5039 to act forward and backward relative to the cam shaft. cam 5106. As the plunger 5039 acts, the magnets 5041, 5107 move with it. A hall effect sensor 5040 detects the movement of the magnet 5041 and another hall effect sensor (which cannot be seen in Figure 345) detects the movement of the magnets 5107.

[0001157] Figure 346 shows a diagram illustrating the use of the pump sensors of Figure 399 when one or more of the sensors are unavailable in accordance with an embodiment of the present description. Figure 345 shows sensors 5042, 5043, 5044, 5045. Rotary position sensor 5042 may be rotation sensor 5037 of Figure 355. Motor hall sensors 5043 may be sensors in motor 5101. Plunger position sensors 5044 and 5045 may be Hall Effect sensors that measure the position of magnets 5040 and 5107 (e.g., Hall Effect sensor 5040 of Figure 345 may be plunger position sensor 5044).

[0001158] Figure 346 can be implemented as a method for using the feedback sensors of a peristaltic pump 5020. The RTP 3500 of Figure 324 can receive sensors 5042, 5043, 5044, 5045. That is, sensors 5042, 5043 , 5044, 5045 may be pump sensors 3501.

[0001159] The RTP 3500 can cross-check the position of the plunger 5039 as indicated by the sensors 5044, 5045 relative to each other. If they do not agree by a predetermined amount, the processor will compare them to one or both of the rotary position sensors 5042 and the Hall Effect sensors 5043 to determine the opening of one of the plunger position sensors 5044, 5045. The RTP 3500 will then use the operative sensor among the plunger position sensors 5044, 5045. If both plunger position sensors 5044, 5045 are unavailable (e.g. not in operation), then the RTP 3500 will use the rotation position sensor 5042 or the motor hall sensor 5043 to estimate the flow rate of the pump 5020. In this case, the RTP 3500 will correlate an RPM of the rotation position sensor 5042 to estimate a flow rate or will correlate the RPM of the motor based on 5043 motor hall sensor to estimate flow rate.

[0001160] The RTP 3500 also cross-checks the 5042 rotary position sensor with the 5043 motor hall sensors. If the 5042 rotary position sensor is inoperative, the RTP 3500 uses the 5043 motor hall sensor.

[0001161] Figures 347 to 350 show the operation of the pump door latch of Figure 399 in accordance with an embodiment of the present description. Shown in Figures 347 to 350 are cross-sectional views to illustrate an operation of hooking the port 5108 that is hooked to the housing 5109 of the pump 5020. Figures 347 to 350 show a sequential progression of using the lever 5046 to hook the port 5108 to the accommodation 5109.

[0001162] Lever 5046 is pivotally coupled to door 5108 via a pin 5058. When lever 5046 is in the fully open position (as shown in Figure 347), a latch 5047 has an angle of rotation about a pivot 5095 so that a pointed end 5048 engages with a detent 5052 of the lever so that the lever 5046 cannot rotate about its axis of rotation via the pivot 5058 towards the housing 5009. That is, when the top 5048 of the interlock 5047 is positioned within the detent 5052 of the lever 5046, the lever 5046 cannot be closed unless the interlock 5047 is disengaged.

[0001163] As door 5108 is closed toward housing 5109, one end 5110 contacts housing 5109, thereby disengaging the pointed portion 5048 of detent 5052, as shown in Figure 348. A spring 5096 drives the interlock 5047 to rotate end 5110 toward housing 5109 (counterclockwise in Figures 347 to 350).

[0001164] As lever 5046 is actuated toward door 5108 (and housing 5109), conveyor 5055 (i.e. conveyor) is actuated toward a slot in housing 5109. Lever 5046 is pivotally coupled to a first link 5056 , which is pivotally coupled to a second link 5057, which is pivotally coupled to carrier 5055. As lever 5046 is actuated toward door 5108, carrier 5055 is pushed into a slot of housing 5109 as shown in Figures 348 and 349.

[0001165] As the lever 5046 is rotated towards the door 5108 and the housing 5109, a hook 5053 hooks onto a pin 5054 to secure the door 5108 to the housing 5109. Figure 350 shows the lever 5046 in a fully closed position. It is also appreciated that a sensor 5050 pivots along a pivot 5111 such that the hook 5053 engages an end 5051 of the sensor 5050 to rotate the sensor 5050 along the pivot 5111 to allow a magnet 5112 to move. The movement of magnet 5112 can be detected by a Hall Effect sensor to determine whether or not lever 5046 is in the fully closed position.

[0001166] In some embodiments, an initial actuation of the lever handle 5046 towards the housing 5108 actuates a valve (e.g., the working ends 3100 or 3111 of Figure 274) to occlude the tube before actuation of the conveyor 5055 in the first 5109 port slot so that the tube is not occluded by the slide occluder.

[0001167] In some embodiments, the lever handle 5046 is functionally coupled to the carrier 5055 so that actuation of the lever handle in the direction of retreat with respect to the housing moves the carrier 5055 in the direction of retreat with respect to the first slot so as to moving a slide occluder disposed within the carrier 5055 to an occluded position so that at least part of the actuation of the lever handle 5046 in the direction of retreat relative to the housing occurs without moving the slide occluder.

[0001168] In another embodiment, an initial actuation of the lever handle 5046 when the lever handle 5046 is in a completely closed position in the direction of retreat from the housing 5109 actuates the conveyor 5055 to an occluding position before actuating the valve to a position non-occlusive.

[0001169] In another embodiment, an initial actuation of the lever handle 5046 in the direction of retreat from the housing 5109 actuates the conveyor to an occluding position before actuating the valve to a non-occlusive position.

[0001170] Figure 351 shows an optical sensor 5113 for estimating parameters of a fluid line in accordance with an embodiment of the present description. Figure 352 shows the optical sensor 5113 of Figure 351 with a fluid line 5063. Light is emitted into a waveguide 5059. The position of the tube 5063 affects the light that travels within the waveguide 5059. A diffuser 5061 does with which part of the light leaves the 5059 waveguide. That is, total internal reflection prevents light from leaving the bottom surface of the 5059 waveguide into the air. As shown in Figure 352, tube 5063 greatly increases the amount of light leaving waveguide 5059, which affects the amount of light leaving diffuser 5060 at various positions. The outside light 5061 is monitored by an image sensor 5062 to determine where and how much of the light leaves the diffuser 5060, which is used to measure the contact of the tube 5063 with the diffuser 506. As shown in Figure 352, there will be less outside light as tube 5063 attracts light, which results in reduced light on the right side (of Figure 352) of diffuser 5060. Image sensor 5062 can use this data to determine the shape of tube 5063 and to estimate its volume. The image sensor 5062 may be coupled to the RTP 3500 of Figure 324. In some embodiments, a plunger (e.g., plunger 3091 of Figure 297) includes the waveguide 5059, the diffuser 5060, and/or the image sensor 5062 to measure a tube parameter 5063. The plunger can be cleaned. In other additional embodiments, the waveguide 5059, the diffuser 5060, and/or the image sensor 5062 may be positioned in a press (e.g., the press 3022 of Figure 297). The press can be cleaned.

[0001171] Image data from image sensor 5062 can be used to measure delivered volume, the extent of change in a pipe 5063 being crushed as part of the pumping mechanism, and/or the extent of water contours in a contained portion of tube 5063 (e.g., between the inlet and outlet valves). A polarizer can be used in front of the 5062 image sensor to intensify the image.

[0001172] In some embodiments, two polarizers are used on both sides of tube 5063 to determine the edges of tube 5063 (e.g., using a birefringence effect) as determined by analysis of image data from the image sensor 5062. Polarizers can polarize light orthogonally to each other. Voltage birefringence creates a colored interference pattern with a light source, e.g. white light source. The varying indices of refraction through the 5063 tube material cause different patterns of constructive and destructive interference. In some embodiments, monochromatic light may be used. In another further embodiment, image data from image sensor 5062 is used to estimate the width of tube 5063 using its voltage profile. In other additional embodiments, two patterns (e.g., grid pattern) are used on both sides of tube 5063 to determine the edges of tube 5063 (e.g., using Moiré patterns) as determined by analysis of the image data. of the image sensor 5062. In other additional embodiments, the image sensor 5062 detects particles within the tube 5063.

[0001173] As shown in Figure 353, the light guides can be layers 5064 to provide a variety of information to the image sensor 5062. Each layer can use different polarizations, orientations, colors, etc. to provide a group of spatially distinct information to the camera 5062.

[0001174] Figures 354 to 355 show the operation of a tube restoration apparatus 5088 in accordance with an embodiment of the present description. Apparatus 5088 includes a first end 5083 and a second end 5082 that compress a tube 5082 to ensure its round shape. The ends 5082, 5083 may be coupled to a support 5088. As a plunger 5085 compresses the tube 5082 (see Figure 355), the plunger 5085 pushes the ends 5082, 5083 in the direction of retreat from the tube 5082. When the plunger 5085 is retracted, a spring action causes the ends 5082, 5083 to restore the shape of the tube 5082.

[0001175] Figures 356 to 357 show the operation of a tube restoration apparatus 5114 in accordance with an embodiment of the present description. Apparatus 5114 includes a first end 5091 and a second end 5092 that compress a tube 5090 to help the tube 5090 maintain a round shape. Ends 5091, 5092 may be coupled to a common point 5089. As a plunger 5093 compresses tube 5090 (see Figure 357), plunger 5093 pushes ends 5091, 5092 in the direction of retreat from tube 5091. When the When the plunger 5093 is retracted, a spring action causes the ends 5091, 5092 to restore the shape of the tube 5090, as shown in Figure 356.

[0001176] Figure 358 shows a circuit 7000 for storing data within an RFID tag 7008 associated with an infusion pump (e.g., the infusion pump 2990 of Figure 255) in accordance with an embodiment of the present description. The RFID tag 7009 of Figure 358 may be the RFID tag 3670 of Figure 325C. The antenna 7001 of Figure 358 may be the antenna 3955 of Figure 325C.

[0001177] The antenna 7001 is coupled to an RFID tag 7008 so that an RFID reader (i.e., RFID interrogator) can communicate with the RFID tag 7008. The circuit 7000 can be placed on a 1x1 inch PCB board with a solid metal ground plane on the back side.

[0001178] An internal loop 7002 with a capacitor 7003 may form a split ring resonator to enhance the read range capability of the circuit 7000. The RFID tag 7008 may be coupled to the antenna 7001 via an impedance matching network 7004 , 7005, 7006, 7007. Circuit 7000 can be configured for use with a 900 Megahertz RFID reader.

[0001179] A reader chip 7009 may interface with the RFID tag 7008 to write data (e.g., logging data) thereto. The 7009 reader chip may communicate with the 7008 RFID tag using I2C, a CAN bus, or other communications link. Alternatively, 7009 may be an electrical connector, in some embodiments.

[0001180] Figure 359 shows an equivalent circuit 7010 for impedance as seen from the RFID tag 7008 of Figure 358 in accordance with an embodiment of the present description. A loop 7011 shows the antenna 7001 of Figure 358. The inductor 7012 shows the inductor 7004 of Figure 358. Resistors 7013 and 7014 are schematic representations of resistors 7006 and 7005, respectively. Capacitor 7015 shows the capacitor 7007 of Figure 359. Circuit elements 7012 to 7015 are used for impedance matching so that the RFID tag 7008 is effectively coupled to the loop antenna 7001 such as in circuit 7000 of Figure 358.

[0001181] Figure 360 shows another circuit 7016 for storing data within an RFID tag 7022 associated with an infusion pump (e.g., the infusion pump 2990 of Figure 255) in accordance with an embodiment of the present description. The 7017 antenna is shown. The RFID tag 7022 of Figure 360 may be the RFID tag 3670 of Figure 325C. The antenna 7017 of Figure 360 may be the antenna 3955 of Figure 325C.

[0001182] Antenna 7017 may have capacitors coupled to gaps in antenna 7017, in some embodiments. An impedance matching network 7018, 7020, 7021 may be used to effectively couple the RFID tag 7022 to the antenna 7017. An interface 7023 may be used to communicate with the RFID tag 7022 (e.g., an I2C interface, an CAN, etc.). Figure 361 shows a split ring resonator 7026 used with the circuit of Figure 360 in accordance with an embodiment of the present disclosure. The split ring resonator 7026 may be printed on a PCB board with an inner loop 7025 and an outer loop 7024. The split ring resonator 7026 may be placed adjacent to the circuit 7016 of Figure 260 to enhance its read range (e.g., the two planes defined by the two PCB boards of the circuit can be parallel to each other).

[0001183] Figure 362 shows an L-shaped cam follower 3800 that has a heated plunger 3820 for engagement with an IV tube in accordance with an embodiment of the present description. The cam follower 3800 includes an L-shaped frame 3802, a plate receiving frame 3818, and a plate 3804.

[0001184] The board 3804 includes a heater 3806 coupled to wires 3810, 3812. The wires 3810, 3812 can be used to apply a voltage difference across the heater 3806 to thereby induce a current to flow through the heater 3806 which heats the heater 3806. A temperature sensor 3808 is disposed within the plate 3804 and is configured to measure a temperature of the plunger 3820. Two wires 3812, 3814 are used to perform a temperature measurement using the temperature sensor 3808. The sensor temperature sensor 3808 may be a thermistor, a Positive Temperature Coefficient resistor, a Negative Temperature Coefficient resistor, a digital temperature sensor, or any other temperature sensor known to one skilled in the relevant art. In some embodiments, two temperature sensors may be used for redundancy, e.g., two temperature sensors may be incorporated into heater 3806, etc.

[0001185] Heater 3806 can apply heat to a tube to which plunger 3820 engages. Because different materials exhibit different characteristics, in some embodiments, heating the tube increases the rate of fluid flow through the tube for each stroke of plunger 3802. Heater 3806 also allows the peristaltic pump to increase the maximum flow rate. in which a pump can pump through the pipe due to the fact that the pipe is more flexible.

[0001186] Figure 363 shows a block diagram of a system 3822 for controlling a peristaltic pump having a heater 3828 in accordance with an embodiment of the present description. System 3822 includes a controller 3824, a motor 3834, one or more sensors 3836, a cam follower 3800, a heater 3828, a temperature sensor 3826, and a tube identifier 3840.

[0001187] Controller 3823 controls the operation of the motor 3834 and the heater 3828. The controller 3823 controls the operation of the motor 3834 to achieve a target flow rate through a tube 3823 (e.g., an IV tube). The controller 3842 sends a signal to an amplifier 3830 which then drives the heater 3828. A temperature sensor 3826 provides feedback to the controller 3824 with respect to the heater 3828. The temperature sensor 3826 may be coupled (e.g., directly or indirectly thermally coupled thereto) to heater 38238, to cam follower 3800, to a cam follower plunger 3800 (see plunger 3820 of Figure 362), or to a race retaining tube 3832. Temperature sensor 3826 may be a thermistor, an NTC device, a PTC device or any other temperature sensor known in the relevant art.

[0001188] As the cam follower 3800 engages the tube 3832, the flow rate of the fluid flowing through the tube 3832 will be monitored by the controller 3824. The controller 3824 uses one or more sensors 3836 to estimate the flow rate. The controller 3824 controls the motor 3834 in response to the estimated flow rate that has been estimated by the controller 3824 using feedback from the sensors 3836.

[0001189] Sensors 3836 may be connected directly to the engine 3834, the drive train 3838 from the engine to the cam follower 3800 (e.g., various cams, shafts, lead screws), and/or to the cam follower 3800 itself (e.g., e.g. cam follower position sensors, actuation sensors, etc.). Sensors 3836 are used by controller 3824 to estimate the volume of fluid discharged through tube 3832 to the patient. Optionally, in some specific embodiments, the volume can be estimated using a spring-driven plunger as described herein.

[0001190] The 3824 controller may use a linear equation to estimate the fluid discharged. For example, the controller may compare the position of the plunger (e.g., plunger 3820 of Figure 362) of the cam follower 3800 when both the inlet and outlet valves are closed when the spring of the cam follower 3800 is pressed against the tube 3832 to determine a full fill volume. Then, after the outlet valve is opened, the plunger can discharge a volume of fluid through tube 3832 to the patient. After the 3800 Cam Follower has discharged as much fluid as possible, another position measurement can be taken to determine the complete discharge volume. That is, the 3800 cam follower plunger is a spring-driven plunger configured to use a spring to impel a volume of fluid to be discharged by the plunger, and a delta movement of the plunger from a full fill volume to a discharge volume. complete may be correlated to a fluid discharge volume by the 3824 controller.

[0001191] The delta movement of the plunger from a full fill volume to a full discharge volume is correlated to an estimated fluid discharge. The correlation between the delta movement of the plunger to the fluid discharge volume may correspond to a predetermined temperature selected to minimize the maximum error flow rate of all of the plurality of tube types.

[0001192] The tube type of the plurality of tube types can be defined as a function of a material of a wall of a respective tube of the plurality of tube types.

[0001193] Correlation can be determined by the 3824 controller using a linear equation that has one or more parameters. One or more parameters can be increased or decreased in accordance with an increase or decrease in the target temperature. The target temperature is set to minimize a maximum error flow rate for a plurality of tube types, wherein the tube is one tube type of the plurality of tubes. The target temperature can be selected to minimize the maximum error flow rate for a plurality of pipe types when using fixed parameters at least one parameter of the linear equation.

[0001194] Correlation can use the equation of ax+b=y. x is the delta movement, and y is the estimated volume of fluid discharged. Parameters a and b are empirically determined coefficients. That is, x is the delta movement of the plunger, and y is the estimated fluid discharge volume while a and b of the linear equation are the parameters of the equation.

[0001195] Controller 3824 can activate heater 3828 in accordance with various embodiments. Heating the 3832 tube makes the material more flexible, thereby facilitating higher flow rates from the 3822 system (or enabling the use of a smaller motor, less stiff spring (or springs) for the 3800 cam follower, or improved power management , etc.).

[0001196] In some embodiments, the controller 3824 may send a plurality of current pulses (e.g., PWM pulses) to the amplifier 3830. The amplifier 3830 may amplify the pulses and send the amplified pulses to the heater 3828 to drive the heater 3828.

[0001197] Heater 3828 may, in some embodiments, be a plurality of heaters. The heater 3828 may be disposed in the cam follower 3800 (e.g., the cam follower plunger). In some embodiments, a plurality of heaters may be disposed in multiple locations, e.g., one or more on the plunger and one or more in the race adjacent to the tube in the pump body, etc.

[0001198] In some embodiments, an insulator may be disposed adjacent to the heater 3828 for direct heat flow from the heater 3828 to the tube 3832. For example, referring back to Figure 362, an insulator may cover the surface of the heater 3806 shown in Figure 362. That is, an insulator can be configured to prevent heat flow to 3818 and 3802 from heater 3828.

[0001199] In one embodiment, controller 3824 activates heater 3828 to reach a target temperature when the pump is programmed to operate beyond a threshold flow rate. For example, if the flow rate is above 700 milliliters per hour (for example), the controller 3824 could, in this specific exemplary embodiment, control the heater 3828 to achieve a target temperature as measured by the temperature sensor 3826.

[0001200] In yet another specific embodiment, the controller 3824 activates the heater 3828 when the system 3822 is unable to achieve a target flow rate. For example, if the target flow rate is 900 milliliters per hour (for example), and the 3834 pump motor at full power cannot achieve a flow rate higher than, for example, 740 milliliters per hour, the controller 3824 activates heater 3828. Heating tube 3832 allows engine 3834 to pump more fluid per cycle. The controller 3824 may control the heater 3828 to enable the system 3822 to achieve a target flow rate. The 3824 controller may initially set the target flow rate at a first value and subsequently increase the target temperature until the target flow rate is reached. In other embodiments, the target temperature may be fixed.

[0001201] In still other additional embodiments, the controller 3824 is coupled to an optional tube identifier 3840. The tube identifier 3840, in some embodiments, may be an RFID interrogator that interrogates an embedded RFID tag attached to or associated with the tube 3832. The controller 3824 can activate the heater 3828 based on which the tube 3832 is loaded into the system 3822. In some embodiments, the target temperature of the controller 3824 is a function of the tube 3832 loaded into the system 3822. The controller 3824 can activate the heater 3828 for 3832 tubes that are produced from a more rigid material, for example.

[0001202] In other additional embodiments, optionally, and in addition or alternatively to tube identifier 3840, a user may enter the tube type on a touch screen or other user interface. The target temperature and/or whether the 3828 heater will activate may be a function of user input. In this specific embodiment, when the heater 3828 is activated, the controller 3824 may cause the display to display a message to plug a power cord coupled to the pump into a power source when the heater 3828 is activated.

[0001203] The predetermined temperature may be predefined and/or may be a function of one or more variables. The predetermined temperature may be selected to achieve a predetermined maximum flow error rate of the controller 3824 when controlling actuation of the plunger to move fluid through the tube 3832.

[0001204] The predetermined temperature can be selected based on a pipe material. The predetermined temperature can be selected to suit a plurality of pipe types. For example, each tube type of the plurality of tube types affects an error flow rate depending on the predetermined temperature. The predetermined temperature can be selected to minimize a maximum error flow rate across the plurality of pipe types. For example, in some embodiments, there is no tube identifier and the predetermined temperature is fixed and is selected to minimize a maximum error flow rate from a set of tube types.

[0001205] Figure 364 shows a flow chart illustrating a method 4500 for infusing fluid into a patient. The method includes actions 4502 to 4514.

[0001206] Action 4502 peristaltically actuates a tube using a peristaltic pump to pump fluid. Act 4504 periodically presses a plunger, of the peristaltic pump, against the tube. Action 4506 controls the heater (for example, to reach a target temperature). The heater may be disposed on the piston (e.g., on a rear portion of the piston on an opposite side of the piston away from the race) or in the race. For example, the peristaltic pump may include a rocker arm coupled to the plunger, and the heater is disposed between the rocker arm and the plunger at the rear of the plunger. The heater can heat a portion of the tube that is actuated by the plunger.

[0001207] Action 4508 controls the heater to reach a target temperature when the pump is programmed to operate beyond a threshold flow rate or when the pump cannot reach a target flow rate without activating the heater. Action 4510 displays a message to plug a power cord attached to the pump into a power source in response to heater activation. Action 4512 heats a portion of the tube that is actuated by the plunger. Action 4514 detects the heat generated by the heater. The peristaltic pump may include a temperature sensor disposed in the piston. The temperature sensor (e.g., a thermistor) may be used as feedback to enable actions 4506 or 4508 to achieve the target temperature. The temperature sensor may be configured to measure a temperature of the tube disposed within a raceway, the temperature of the heater and/or the temperature of the plunger. The clue may be arranged inside the door.

[0001208] The operation of the pump can be controlled by controlling the heating of the heater. For example, the heater can be used to increase the maximum flow rate of the peristaltic pump by softening the tube. In some embodiments, the heater is activated when a predetermined type of tube is loaded into the raceway. The target temperature may be based on the set (e.g., IV set or IV tube) loaded (e.g., loaded into the lane). The set can be determined based on user input in a user interface.

[0001209] Figures 365A and 365B show a flowchart of a method 4516 for calibrating a pump in accordance with an embodiment of the present description. The pump may be a peristaltic pump. For example, the pump may include: (1) a plunger and spring configured to urge the plunger toward a tube, (2) a heater configured to thermally transfer heat to the tube, (3) an actuator configured to actuate the plunger in the opposite direction to the tube and against the spring force, and (4) a controller. The controller can control the heating of the heater.

[0001210] Method 4516 may include actions 4518 to 4540. Action 4518 seals a volume of fluid within a segment of the tube. The 4520 action allows the spring to compress the tube segment. Action 4522 determines a first plunger position when the plunger spring urges the plunger against the tube, and the actuator is not engaged with the plunger. Action 4524 discharges the fluid volume within the tube segment using the plunger by removing the fluid volume seal within the tube segment. Action 4526 determines a second position of the plunger after the fluid has discharged the volume of fluid, wherein the actuator disengages from the plunger to allow the spring to discharge all fluid that can be discharged. Action 4528 determines a delta between the first position and the second position of the plunger.

[0001211] Action 4530 correlates the delta to an estimated volume of fluid discharged. Action 4532 heats a portion of the tube to a target temperature. Action 4534 measures the actual volume of fluid discharged. Action 4536 repeatedly performs actions 4518 to 4534 using a plurality of tube types. Each type of the plurality of tube types is defined by a material.

[0001212] Action 4538 selects a target temperature to minimize a difference between the estimated volume of fluid discharged and the actual measured volume of fluid discharged for all of the plurality of tubes.

[0001213] Action 4540 selects the parameters of the correlation function of action 4530 to minimize a difference between the estimated value of fluid discharged and the actual measured volume of fluid discharged for the entire plurality of pipes for the selected target temperature.

[0001214] The estimated volume of discharged fluid can be estimated using a linear equation that has one or more parameters during the correlation action. Parameters can be increased or decreased in accordance with an increase or decrease in the target temperature. In some embodiments, the target temperature may be selected to minimize the maximum error flow rate for a plurality of pipe types when using the fixed parameters of the linear equation. The linear equation can be ax+b=y, where x is the delta movement of the plunger, and y is the estimated fluid discharge volume. At least one parameter of the linear equation may include a and b of the linear equation, in this specific embodiment.

[0001215] Various alternatives and modifications can be devised by those skilled in the art without departing from the description. Accordingly, the present description is intended to encompass all such alternatives, modifications and variances. Additionally, although various embodiments of the present description have been shown in the drawings and/or discussed herein, the description is not intended to be limited thereto, as the description is intended to be as broad in scope as the art permits and that the descriptive report is read in the same way. Therefore, the above description should not be interpreted as limiting, but merely as exemplifications of particular modalities. And, those skilled in the art will appreciate other modifications to the scope and spirit of the claims appended thereto. Other elements, steps, methods and sets of techniques that are insubstantially different from those described above and/or in the appended claims are also intended to be within the scope of the description.

[0001216] The embodiments shown in the drawings are presented only to demonstrate certain examples of the description. The drawings described are for illustrative purposes only and are not limiting. In the drawings, for illustrative purposes, the size of some of the elements may be exaggerated and not drawn to a particular scale. Additionally, elements shown in the drawings that have the same numbers may be identical elements or may be similar elements, depending on the context.

[0001217] When the term "comprising" is used in the present description and claims, it does not exclude other elements or steps. When an indefinite or definite article is used when referring to a singular noun, for example, "a" or "the" it includes a plural of the noun unless something is specifically stated otherwise. Therefore, the time "comprising" should not be interpreted as being restricted to the items listed below; does not exclude other elements or steps, and so the scope of the expression "a device comprising items A and B" should not be limited to devices consisting only of components A and B. This expression means that, in relation to the present description, the only relevant components of the device are A and B.

[0001218] Additionally, the terms "first", "second", "third" and the like, whether used in the description or in the claims, are provided to distinguish between similar elements and not necessarily to describe a sequential or chronological order. It should be understood that terms used in this manner are interchangeable in appropriate circumstances (unless clearly disclosed otherwise) and that embodiments of the description described herein have the capability of operation in other sequences and/or attachments that are described or illustrated in this document.

Claims (41)

1. Peristaltic pump, comprising: a conduit configured to retain a tube (3832); a plunger (3820) configured to act on the tube (3832) disposed within the conduit; and a motor (3834) configured to couple the plunger to actuate the plunger (3820); characterized by the fact that it comprises: a heater (3806, 3828) arranged in thermal conductive contact with the tube (3832); and a rocker arm coupled to the plunger (3820), wherein the heater (3806, 3828) is disposed between the rocker arm and the plunger (3820) at the rear of the plunger, the rear of the plunger being on an opposite side of the plunger (3820 ) away from the conduit. 2. Peristaltic pump, according to claim 1, characterized by the fact that it further comprises a temperature sensor disposed on the plunger (3820). 3. Peristaltic pump according to claim 2, characterized in that the temperature sensor is a thermistor. 4. Peristaltic pump according to claim 2 or 3, characterized in that the temperature sensor is configured to measure a temperature of the tube (3832) disposed within the conduit. 5. Peristaltic pump according to any one of claims 2 to 4, characterized in that the temperature sensor is configured to measure a temperature of the heater (3806, 3828). 6. Peristaltic pump according to any one of claims 5 to 8, characterized in that the temperature sensor is configured to measure a temperature of the plunger (3820). 7. Peristaltic pump according to any one of claims 1 to 6, characterized in that the heater (3806, 3828) is disposed within the conduit and is configured to heat the tube (3832) retained within the conduit. 8. Peristaltic pump according to any one of claims 1 to 7, characterized in that the conduit is arranged in a port. 9. Peristaltic pump according to any one of claims 1 to 8, characterized in that it further comprises: a heater controller (3823, 3824) configured to control the heating of the heater (3806, 3828); and a temperature sensor configured to detect heat generated by the heater (3806, 3828). 10. The peristaltic pump of claim 9, wherein the heater controller is configured to control the heater (3806, 3828) to reach a target temperature when the peristaltic pump is programmed to operate beyond a rate limit flow. 11. The peristaltic pump of claim 9 or 10, wherein the heater controller (3823, 3824) is configured to activate the heater (3806, 3828) when a predetermined type of tube (3832) is loaded. inside the conduit. 12. Peristaltic pump according to any one of claims 9 to 11, characterized in that the heater controller (3823, 3824) is configured to establish a target temperature based on a load established in the conduit. 13. Peristaltic pump according to any one of claims 9 to 11, characterized in that the heater controller (3823, 3824) is configured to adjust a target temperature based on a loaded set. 14. Peristaltic pump according to claim 13, characterized by the fact that it further comprises a user interface, wherein the loaded set is determined based on user input in the user interface. 15. Peristaltic pump according to any one of claims 1 to 14, characterized in that a controller is coupled to the heater (3806, 3828) to control the operation of the peristaltic pump. 16. Peristaltic pump according to any one of claims 1 to 15, characterized in that it further comprises a plurality of heaters including the heater, wherein each of the plurality of heaters is in thermal conductive contact with the tube (3832 ). 17. Peristaltic pump according to claim 16, characterized in that the heater of the plurality of heaters is disposed on the piston (3820) of the peristaltic pump. 18. Peristaltic pump according to any one of claims 1 to 17, characterized in that it further comprises an insulator disposed adjacent the heater (3806, 3828), the insulator being configured to direct thermal flow from the heater (3806, 3828 ) towards the tube (3832). 19. Peristaltic pump according to claim 18, characterized in that the heater (3806, 3828) is disposed on the plunger (3820) and the insulator is disposed on at least one side of the heater (3806, 3828) opposite to one side that faces the tube (3832). 20. Peristaltic pump according to any one of claims 1 to 19, characterized in that it further comprises a controller operatively coupled to the heater (3806, 3828), wherein the controller operatively sends a plurality of current pulses to the heater (3806, 3828) to heat the heater (3806, 3828). 21. Peristaltic pump according to any one of claims 1 to 20, characterized in that it further comprises a controller configured to heat the heater (3806, 3828) to a predetermined temperature. 22. Peristaltic pump according to claim 21, characterized in that the predetermined temperature is selected according to a plurality of tube types. 23. The peristaltic pump of claim 22, wherein a tube type of the plurality of tube types is defined as a function of a material of a wall of a respective tube of the plurality of tube types. 24. The peristaltic pump of any one of claims 1 to 23, wherein the plunger (3820) is a spring-loaded plunger configured to use a spring to force a volume of fluid to be discharged by the plunger (3820 ), wherein a delta movement of the plunger (3820) from a fill volume to a discharge volume is correlated with a fluid discharge volume. 25. A peristaltic pump comprising: a conduit configured to retain a tube (3832); a plunger (3820) configured to act on the tube (3832) disposed within the conduit; a motor (3834) configured to engage the plunger (3820) to drive the plunger (3820); characterized by the fact that it further comprises: a heater (3806, 3828) disposed in thermal conductive contact with the tube (3832); a heater controller (3823, 3824) configured to control heating of the heater (3806, 3828); and a temperature sensor configured to sense heat generated by the heater (3806, 3828), wherein the heater controller (3823, 3824) is configured to control the heater (3806, 3828) to reach a target temperature when the peristaltic pump cannot achieve a target flow rate without activating the heater (3806, 3828). 26. Peristaltic pump comprising: a conduit configured to retain a tube (3832); a plunger (3820) configured to act on the tube (3832) disposed within the conduit; a motor (3834) configured to engage the plunger (3820) to drive the plunger (3820); characterized by the fact that it further comprises: a heater (3806, 3828) disposed in thermal conductive contact with the tube (3832); and a display configured to display a message to plug a power cable coupled to the peristaltic pump into the power source when the heater (3806, 3828) is activated. 27. A peristaltic pump comprising: a conduit configured to retain a tube (3832); a plunger (3820) configured to act on the tube (3832) disposed within the conduit; a motor (3834) configured to engage the plunger (3820) to drive the plunger (3820); characterized by the fact that it further comprises: a heater (3806, 3828) disposed in thermal conductive contact with the tube (3832); a plurality of heaters including the heater (3806, 3828), wherein each heater of the plurality of heaters is in thermal conductive contact with the tube (3832), wherein the heater of the plurality of heaters is disposed on the plunger (3820) of the pump peristaltic; another heater of the plurality of heaters is disposed on the piston (3820), and the other heater is not disposed on the piston (3820). 28. Peristaltic pump according to claim 27, characterized by the fact that the other heater is disposed in the conduit. 29. The peristaltic pump of claim 27, wherein the other heater is disposed adjacent to the tube (3832) in a pump body of the peristaltic pump. 30. A peristaltic pump comprising: a conduit configured to retain a tube (3832); a plunger (3820) configured to act on the tube (3832) disposed within the conduit; a motor (3834) configured to engage the plunger (3820) to drive the plunger (3820); characterized by the fact that it further comprises: a heater (3806, 3828) disposed in thermal conductive contact with the tube (3832); a controller operatively coupled to the heater (3806, 3828), wherein the controller operatively sends a plurality of current pulses to the heater (3806, 3828) to heat the heater (3806, 3828); and an amplifier for amplifying the plurality of current pulses before they are sent to the heater (3806, 3828). 31. A peristaltic pump comprising: a conduit configured to retain a tube (3832); a plunger (3820) configured to act on the tube (3832) disposed within the conduit; a motor (3834) configured to engage the plunger (3820) to drive the plunger (3820); characterized by the fact that it further comprises: a heater (3806, 3828) disposed in thermal conductive contact with the tube (3832); and a controller configured to heat the heater (3806, 3828) to a predetermined temperature, wherein the predetermined temperature is selected to achieve a predetermined maximum flow error rate of the controller when controlling the plunger driver (3820) to move the fluid through the tube (3832). 32. Peristaltic pump according to claim 31, characterized in that the predetermined temperature is selected based on a tube material (3832). 33. A peristaltic pump comprising: a conduit configured to retain a tube (3832); a plunger (3820) configured to act on the tube (3832) disposed within the conduit; a motor (3834) configured to engage the plunger (3820) to drive the plunger (3820); characterized by the fact that it further comprises: a heater (3806, 3828) disposed in thermal conductive contact with the tube (3832); and a controller configured to heat the heater (3806, 3828) to a predetermined temperature, wherein the predetermined temperature is selected according to a plurality of tube types, and wherein each tube type of the plurality of tube types affects a flow rate error depending on the predetermined temperature. 34. The peristaltic pump of claim 33, wherein the predetermined temperature is selected to minimize a maximum error flow rate of all pluralities of tube types. 35. The peristaltic pump of claim 34, wherein the plunger (3820) is a spring-loaded plunger configured to utilize a spring to force a volume of fluid to be discharged by the plunger (3820), wherein a delta movement of the plunger (3820) from a full fill volume to a full discharge volume is correlated with a fluid discharge volume. 36. The peristaltic pump of claim 35, wherein the correlation between the delta movement of the plunger (3820) to the fluid discharge volume corresponds to a predetermined temperature selected to minimize the maximum error flow rate of all the plurality of tube types. 37. A peristaltic pump comprising: a conduit configured to retain a tube (3832); a plunger (3820) configured to act on the tube (3832) disposed within the conduit; a motor (3834) configured to engage the plunger (3820) to drive the plunger (3820); characterized by the fact that it further comprises: a heater (3806, 3828) disposed in thermal conductive contact with the tube (3832); wherein the plunger (3820) is a spring-loaded plunger configured to utilize a spring to force a volume of fluid to be discharged by the plunger (3820), wherein the delta movement of the plunger (3820) from a full fill volume to a total discharge volume is correlated with an estimated fluid discharge volume, and wherein the correlation is determined using a linear equation having at least one parameter. 38. Peristaltic pump according to claim 37, characterized by the fact that a parameter of the at least one parameter is increased or decreased according to an increase or decrease of a target temperature. 39. The peristaltic pump of claim 37 or 38, wherein the target temperature is set to minimize a maximum error flow rate for a plurality of tube types, the tube being a tube type of the plurality of tubes. 40. The peristaltic pump of claim 39, wherein the target temperature is selected to minimize the maximum error flow rate for a plurality of tube types (3832) when using fixed parameters of the at least one parameter of the linear equation. 41. Peristaltic pump according to any one of claims 37 to 40, characterized by the fact that the linear equation is ax+b=y, where x is the delta movement of the plunger (3820) and y is the fluid discharge volume estimated, where the at least one parameter includes the a and b of the linear equation.