DE2144096A1 - Pump device - Google Patents

Description

Patent attorneys Dipl.-Ing. F. WeickMann,

Dipl.-Ing. H.Weickmann, Dipl.-Phys. Dr. K. Fincke Dipl.-Ing. F. A. WEICKMANN, Dipl.-Chem, B. Huber

₈ MUNICH 86, DEN 2144096

PO Box 860 820

MÖHLSTRASSE 22, CALL NUMBER 48 3921/22

<983921/22>

STERNWOOD MEDICAL INDUSTRIES INC.

1831 Olive Street

St. Louis, Missouri, Y.St.A.

Pu mpene device

The invention "relates to a Purapen device, particularly the usable for use in an infusion device is.

Usually used with blood transfusions and intravenous injections a hook with the infusion solution hung over a patient to allow the fluid to aground gravity through an infusion tube (venoclysis tubing), which can be thrown away after use, flow to a catheter inserted into the patient's vein is. Transporting the patient is difficult because the infusion bottle must always be above the patient, so a carer is required to hold the solution bottle. Even if the patient is in a hospital, the process must be monitored periodically, so that valuable working time is required, in spite of periodic monitoring Bestiaate functional errors can occur that go unnoticed stay because a suitable ad for the faulty

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ORIGINAL INSPECTED

Function is missing «During an injection it is possible, for example, that a needle moves out of its position in a Vein displaced and penetrates a muscle »

The invention is based on the object of creating an improved infusion device in which the sterile parts that come into contact with the pumped fluid are discarded after use and simply thrown through new sterile parts can be replaced. In addition, the above-mentioned and in the following should be explained in more detail explained shortcomings of known devices are corrected.

According to the invention there is a new portable pump device created with positive displacement, which replaces the gravity infusion system that was previously used for Transfusions and infusions is used. Therefore, the solution bottle can be placed at any reasonable height lying to the patient. A novel, battery-operated control circuit for the pump device has several safety circuits that automatically prevent unhealthy conditions ^ for example the passage of air bubbles or a displacement the intravenous needle into a muscle, so that it is no longer necessary for a nurse to periodically monitor the process. Become sterile conditions easily maintained because the pump device with positive displacement uses a disposable syringe and a two-way valve that is disposable after use, these Parts removed after use on a single patient and replaced with a new sterile syringe and valve can be replaced.

Some attempts have already been made to use disposable syringes for pumping fluid at specified locations For example, trying to use «E * was the piston to drive a Spritae by an AC motor »

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ORIGINAL INSPECTED

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which is connected to an external AC line. To control the Purap speed there is an adjustment intended for the length of the working stroke of the piston. Such an idfc device cannot be used in an infusion device, because air bubbles can get to the patient and because other serious malfunctions occur on the other hand that cannot be resolved automatically. With this device it is also not possible to use the syringe pre-fill, nor is precise control possible, as is essential for an infusion device.

The new type of control circuit to drive the new pump unit has a new type of drive for a DC motor, which is also used to precisely drive others Loads than can be used by pumps. The drive automatically compensates for fluctuations in the load and long-term aging the batteries to power the control circuit and finally senses harmful conditions on the driven Load off. The reversal of the motor movement is achieved by a simple reverse circuit, which is achieved by the Movement of the motor armature is controlled. The control circuit drives the DC motor by pulses of variable width on and monitors the back electromotive force on the motor during the time between pulses, by the pulse width to control the impulses. So far, two such circuits are necessary when a motor is in both the forward and should also be driven in the reverse direction «The control circuit according to the invention enables the same measure to control, but the circuit is considerably simplified.

An improved control circuit is therefore provided in accordance with the present invention to cycle a DC motor through one duty cycle to be driven with strokes in two directions. According to another aspect of the invention

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is an improved pump device that is provided by a DC motor is driven, and a feedback device is created to control the operation of the control circuit modified in accordance with external conditions influenced by the operation of the pump.

Embodiments of the invention will now be based on the attached drawings. Show it:

1 shows a perspective illustration of an infusion device with the pump device according to the invention;

2 shows an exploded view of the pump device, with the syringe pump on the opposite side of the pump housing for clarity, such as it is shown in Fig. 1;

Pig. 3 shows a representation, partly in plan view and partly in section, of a disposable valve with embedded electrodes;

Pig. Figure 4 is a section along line 4-4 of Pig. 3;

Pig. Figure 5 is a top plan view taken along line 5-5 of Pig. 4; and

Fi _fe "6 is a schematic representation of the control circuit for the pumping means.

A portable infusion device (Pig, 1) is provided, to pump fluid, such as blood, from a solution bottle 20 to a catheter 21 inserted into the vein of a patient is used. The fluid conveyance is carried out by a pump device 24, which is held by a holder 26, which in turn on a Rail 28 of a bed is arranged for the patient.

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The bracket 26 also releasably holds the solution bottle 2o, which is at any reasonable height relative to the Patients can be arranged.

The solution bottle 20 is constructed in a conventional manner and has a cap 30 with an air valve 31 and a discharge port 32 for fluid transfer. A Infusion tube 34, which can be thrown away after use, connects the mouth 32 to the inlet port a two-way disposable valve 40, which is part of the pump device 24.

The pump device 24 uses a conventional disposable syringe 42 with a sliding piston as the pump chamber 44, which can be reciprocated to pump fluid in the hollow syringe barrel connected to the two-way valve 40 is connected, which has an outlet 46, which through the infusion tube 50 with a conventional Y-connector 52 connected for the introduction of drugs is. The output of the Y-connector 52 is through a further infusion tube 54, which can also be thrown away after use, is coupled to the catheter 21.

The control circuit for the pump device 24, which is shown in Fig. 3, is completely in the housing for contain the pump device and can either from the outside or from the inside, for example by a battery, with Be supplied with electricity. During the return stroke in which the syringe plunger 44 is moved away from the valve 40, can the inlet port 36 feeds fluid from the solution bottle 20 into the syringe barrel. The outlet 46 of the The valve is closed at this point. During the forward stroke, in which the piston 44 towards the valve 40 is moved, the inlet 36 is closed and the outlet

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open so that the solution is pumped through the infusion line 52 and 54 to the catheter 21.

The pump assembly 24 is shown exploded in Pig. 2 shown. A sterile positive displacement pump is economically formed by using a conventional disposable syringe 42 in conjunction with a novel disposable valve 40 to be described later it is movable in a hollow cylinder 72 having a single fluid port, which terminates in a port 74 for a needle, 'the syringe has lugs 76 on the finger grips which are held in the present invention by retaining means for the pump means 24th

The syringe 42 and valve 40 are releasable from a housing kept to be removed from each patient after use and through a new sterilized syringe and to be able to replace a sterilized valve. A cast housing base 90 has two upstanding arms 92, each having a slot-shaped channel 94 which one of the lugs 76 on the syringe. The lower part of the housing 90 also has an upstanding pin 100 with a concave surface 102 to close valve 40 hold when attached to syringe 42 and make electrical contact with those embedded in the valve Manufacture electrodes. Two electrical sockets I06 in the area 102 accept electrodes of a detector for air bubbles on. A female connector 108 (not shown in Pig * 2) arranged separately from the base 90 or on the like Way can be cast in a part of the same, takes an electrode of an overpressure detector. The connector sockets 106 and 108 are connected by wires with that shown in JKg, 3 Connected circuit, which is located in the hollow housing

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part 90 is included.

The mechanical drive for the piston 44 consists of a reversible direct current motor 120i of an armature shaft with an integral motor gear 122. The motor gear 122 meshes with an idle gear 126 which is rotatable about an idle shaft 128 which is fixed to a pinion 130 is attached. The pinion 130 meshes with a drive gear 132 which is fixed to the shaft of a screw spindle 134 is attached. A syringe cylinder carrier 140 has a gripping head 142 which has an opening to the head 45 of the Piston 44 slidably received. The carrier 140 has a Raittige bore provided with a thread on the inside, in which the threads of the screw spindle 134 engage, so that the carrier acts as a drive nut on the screw spindle. works.

When the DC motor 12ο by a voltage predetermined Polarity is excited, the two-stage reduction spur gears rotate the screw spindle 134 and drive the carrier 140 and associated piston 44 on a forward stroke. The carrier 140 has a protrusion 150 with a permanent magnet extending downward and magnetic with a sealed limit switch 152 for the forward stroke and cooperates with a sealed limit switch 154 for the Rüokhub that on a circuit board 156 are attached, which the circuit according to Pig. 3 carries. The carrier 140 is in the forward direction driven until protrusion 150 is directly over limit switch 152. At this point the circuit turns of Fig. 3, the polarity of the voltage for the DC motor 120 in order to the armature 121 in the reverse direction to turn. The carrier 140 and the piston 44 are now moved in the longitudinal direction by a return stroke until the projection 150 is directly above the limit switch 154.

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At this point the circuit of Pig returns. 3 again the polarity of the voltage of the DC motor 140 µm. While magnetically "operated proximity switches are preferred, Mechanical switch devices can also be used, which are activated by mechanical engagement with the protrusion are operable.

The power for the DC motor 120 and the control circuitry comes from a built-in DC power source, for example from two series connected DC batteries 160. Preferably The batteries 160 are rechargeable, sealed nickel-cadmium batteries that allow the pump " device can be supplied either from an external AC source or from the built-in power source can make the facility fully portable. If the device is intended as a portable device only the batteries 160 may be conventional 1.5 volts, "D" size. Me DC batteries 160 are in one Battery receiving cylinder 162 housed, which is in the lower housing part 90 is cast. The electrical connection is made by a battery contact spring 164 and a contact made on a battery retaining cap 165 which can be screwed into the wall of the battery receiving finder so that the batteries can be replaced if necessary.

A top housing 170 fits onto the bottom housing 90 to enclose the drive device and batteries 160. The top 170 has a window 172 through which markings on a thumbwheel 174 are observed can allow the operator different pumping speeds for the fluid can select. Preferably, the markings on wheel 174 point directly the pumping speed, for example 1 liter of fluid per 1, 2, 3, etc. hours. Another range of pumping speeds may be provided by replacing syringe 42 with a syringe of different capacity. That

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Wheel 174 can then also be provided with other markings. A switch 176 for actuation at the initial Filling the syringe enables the operating personnel to be informed by the ftfl. 174 override selected setting, to quickly reciprocate the plunger 44 the first time the syringe 42 is filled to remove air bubbles eliminate. While currently in which the switch I76 is operated the air bubble protection circuit is turned off.

Disposable Tentil ^ arrangement

The single-use valve assembly 40 is shown in detail in FIGS. The arrangement becomes economical formed by using two identically manufactured valve units 190, which in opposite flow directions with a flow channel unit in the middle 192 are assembled so that a valve unit 190 the inlet 36 and the other valve unit I90 the outlet 46 forms.

Each valve unit 190 has a fluid inlet port with a tapered conical wall 194 which directs the fluid to a check valve 195, made of a flexible, resilient material such as rubber. The check valve 195 is through a hollow central portion formed with an integral tapered nose 196 which fits into a rectangular slot opening 197 ends dispensing fluid at an outlet port. The outlet mouth is through a tubular Wall 200 formed, which also serves as anchoring of the hollow central portion of the backlash valve. The check valve 195 is conventionally constructed and allows fluid in one direction from the inlet port, formed by the conical wall 194 to the outlet mouth formed by the tubular wall 200 will flow. However, the check valve falls in itself

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together and blocks the flow in the opposite Direction.

The flow channel unit 192 arranged in the middle has an inlet channel 202 into which the outlet port of the Valve unit 190 is inserted, which forms the inlet 36. An exit channel is located opposite the flow channel 202 having a conical wall that receives the conical port 94 of the syringe. There is an output channel next to channels 2o2 and 203 204 and a closed channel 2o6. The channel 2o4 terminates in a neck 208 of reduced diameter, which extends in the inlet port of the valve unit 190 fits as the outlet 46 serves to deliver the flow of fluid to the catheter.

In order to sense the presence of an air bubble in the fluid channel, two rod-shaped metal electrodes 212 extend through the wall of the valve assembly into the fluid channel 204. The electrodes 212 are approximately 6 mm apart and are arranged in front of the check valve 195 serving as the exit. When a fluid with 0.001 fi salinity or is no longer present between the electrodes 212, the fluid flows through a resistive path, the resistance is sufficiently low so that the circuit of Pig. 3 can continue to work. When an air bubble of a predetermined size passes the electrodes, the impedance increases and breaks the circuit, stopping the forward stroke of the pump.

In order to determine an overpressure, as it is built up when the catheter penetrates a muscle, the closed one forms Fluid channel 206 a pressure detector. A cap 217 closes the end of the fluid channel 2o6, so that between the cap 217 and the one entering the channel 2o6 Fluid air is trapped. A single rod-shaped metal electrode 220 is through the wall

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of the valve assembly is inserted into the fluid channel 206. When an overpressure occurs, the fluid pressure pushes in the middle channel unit 192 the included one Air further together so that the fluid can continue to enter the closed channel 206 until it comes with the electrode 220 comes into contact. This creates a circuit through the fluid to one of the electrodes 212 closed to indicate overpressure.

Preferably, electrodes 212 and 220 are integral with valve assembly 40 rather than part of syringe 42 intended. This means that a conventional, inexpensive disposable syringe can be used as a pump. The valve assembly itself can be economically injected or cast from a plastic material, with the exception of the two non-return valves 140, which can be molded from rubber. The outwardly extending ends of the metal electrodes 112 and are inserted directly into the sockets 106 and 108, as described above.

The control circuit for the Purapen device is in detail shown in fig. A DC voltage is applied between a DC voltage line 248 and a source for a Reference potential or earth 250. If an external 115 volt alternating voltage is present, a plug 256 can be plugged into the external AC power source to power the 115 volts AC to a coaster transformer 258 to pair. The transformer is connected to a line 260 through a full-wave diode rectifier, which can be connected to the line 248 by a socket. The rechargeable batteries 160 form a pIter capacity for the AC voltage rectified in the full-wave rectifier, so that the ripple of the voltage on the DC

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Voltage line 248 is reduced. If necessary, an additional filter capacitor 262 can be provided. The step-down transformer 258 and the full-wave rectifier can be arranged in the connector 256 and by a two-wire cable with the plug "socket on the Purapen device be connected. If the Purapen device is to be used independently of the external AC power source, then only the cable plug removed from the socket on the Purapeneinrichtung, so that the previously charged Batteries 160 then power the control circuit.

The DC motor 120 is a wound as a shunt, * permanent magnet motor, which rotates in the forward direction when the current flows from a terminal 260 to a terminal 262, and rotates in a reverse direction when the current from the terminal 262 to the terminal 260 flows. As will become clear, the motor is driven by pulses that have a duty cycle of less than $ 100. During the time between pulses, motor 120 acts as a generator or tachometer, and the back electromotive force at the terminals is sampled and stored to control the duty cycle of the drive pulses.

An electronic reversing switch with transistors 265, 266, 267, 268, 269 and 270 forms a reversing switch with two

Switching positions, the transistors 265 and 268 become synchronous brought into the conductive state to pass current in the forward direction through the motor 12o. On the other hand, the Transistors 266 and 267 synchronously in the conductive state to close a reverse current path for motor 120 to drive the motor through its return stroke. When transistors 265 and 268 are on, current flows from positive line 275 through the transistor 265 to terminal 26o of motor 120, through the motor 120 and through terminal 262 to transistor 268 and from

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- ORIGINAL INSPECTED

there to earth 250 · When the front limit of the stroke is reached is what is indicated by the permanent magnet on the protrusion 150 actuating the limit switch 154, switches an inverse switching driver, to be described later, the transistors 265 and 268 off and transistors 266 and 267 on. Current will now flow through the positive lead 265 Transistor 266 to terminal 262 and thence through motor 120, from terminal 260 to transistor 267, and from there to earth.

The reverse switching driver, which consists of transistors 280, 281, 282 and 283, acts as a regenerative bistable Switch with which the large drive capacity can be achieved which is necessary when a low supply voltage, for example 3 volts from two batteries 160, is used. The transistors 280 and 283 drive each other into saturation when the permanent magnet is on the protrusion 150 actuates limit switch 152 at the end of a return stroke, the base of transistor 282 being grounded. Otherwise Transistors 282 and 281 drive each other into saturation when the permanent magnet is on the protrusion 150 actuates limit switch 154, with the base of transistor 283 grounded at the limit of the forward stroke will.

When transistor 281 goes into saturation, current flows from its emitter to the base and through a resistor 290 to the base of transistor 267 to achieve a level for creating the reversing switch. At the same time, the voltage at the collector of transistor 281 increases to the potential of line 275, so that the transistors 269 and 265 are biased in the reverse direction. The transistor 282 is also in saturation at this time, so that a current through the emitter-base path of transistor 266, through resistor 292 and through a Line 293 to the collector of transistor 282 and from

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there flows to earth 250. This creates a level control the other half of the reversing switch is created. Since the collector voltage of transistor 282 is approximately ground potential, no current flows through a resistor 295 to the transistor 270 or to the transistor 268. If the other stable condition of the "bistable circuit" is made by the permanent magnet is set on the approach 250, the transistors act 280 and 281 similar to the above-described mode of operation of the transistors 281 and 282, so that a control for transistors 265 and 269 and transistors 268 and 268 are provided as will be discussed with reference to the bubble detector circuit is explained.

During the gate stroke, the transistor 270 is driven into the high-speed state by pulses which have a duty cycle of approximately 25 ⁰ Jo . In an already manufactured circuit, the drive pulses for the minimum motor speed had a pulse duration of 4 milliseconds and one. Pulse gap between the pulses of 16 milliseconds, so that a frequency of 60 Hz was generated. The pulse duty factor during the forward stroke is adjustable, as will be described below, and is controlled by a control circuit for the forward stroke.

The return stroke is always carried out at maximum speed, since transistors 266 and 267 are fully saturated during the reverse motion of the motor. Because the DC voltage of the I60 batteries slowly with aging and use decreases, a lower voltage is applied to the DC motor 120 through the return stroke transistors 266 and 267 passed so that there is a slower speed the movement results. A compensation circuit for battery voltage fluctuations speaks to a reduced battery voltage on and reduces the switch-off time between the pulses controlled by the forward stroke control so that the speed in the forward stroke orhtfht

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to set the selected pump speed to the right.

The forward stroke control has transistors 300, 301, 302, 303 and 304, which are connected essentially as an asymmetrical, astable ilultivibrator. In order to be able to select different pumping speeds, the thumb wheel 174 is connected to a slider 310 of a switch 312 with several switching positions. The wiper 310 is connected to one of a number of resistors 315, each of which has a different resistance value. An "OFF ^u main switch 316, when actuated, connects the wiper 310 to the (DC voltage line 248 via a start switch 176. When the duration wheel 174 is rotated so that the wiper 310 of the switch 312 engages a certain resistor 315, a path from the DC voltage line 248 through actuated switch 316 and non-actuated switch 176 to the wiper and from there through selected resistor 315 to the emitter of the transistor

300 formed. The collector of transistor 300 is through a capacitance 317 and from there through the collector-emitter path of transistor 301 connected to ground 250. The duty cycle of the pulse coupled to transistor 270 is, by the capacitance of capacitor 317, the value of the selected Resistor 315 and the voltage at the base of transistor 300 (determined by the speed feedback circuit comes, as will be described below).

The switch-on time of the pulse cycle is determined by the time interval during which transistors 301 and 303 are saturated and transistors 302 and 304 are off. The transistor 300 acts as a controlled current source which discharges the capacitance 317 during the time during which it keeps transistor 304 off. When the transistor

301 turns on, the transistor 303 is turned on by a current flowing from its base and through a resistor

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ORIGINAL INSPECTED

stood 320 and the conductive transistor 301 to earth 350 flows. Transistor 303 drives transistor 270 of the reverse switch driver through resistor 322. On top of this Way is the holding time (pulse duration) of the pulse cycle, which controls the forward stroke of the motor, determined by the saturation of transistor 303.

The switch-off time (irapulse gap) of the pulse cycle is through the saturation of transistor 304 is controlled, at which time transistors 301 and 303 are off. The switch-off time is determined by the capacity of a capacitor 325, is the voltage to which capacitor 325 rises during the previous switch-on time, and the resistance values two resistors 327 and 328 connected in series. The allowable voltage on which the capacitor is 325 can charge, is set by the compensation circuit for battery voltage fluctuations, as will be described later.

The operation of the forward stroke control circuit is as follows. Assume that transistor 301 is just turned on where "oei the capacitance 317 is fully charged and the capacitance 325 is fully discharged. When the transistor 301 saturates is, the negative terminal of the capacitance 317 has a negative voltage equal to the supplied potential. For example, it is assumed that the previous potential from the batteries I60 is at the maximum potential, i.e. H. 3.0 volts. A current now flows from the + 3 volt source through switches 316, I76 and 310 to the selected one Resistor 315 and from there through transistor 300 to the discharge capacitance 317. If the negative connection of the capacitance 317 reaches 1.2 volts (base-emitter drop of transistors 302 and 304), transistors 302 and 304 switched on, the transistor 301 switched off and the capacitance 317 to the supply voltage via a resistor 330 being charged. The capacity 325 discharges

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through the series-connected resistors 327 328 until the base smitter voltage of transistor 301 is reached. At this point the! Transistor switches 301 a and. the cycle is repeated »

During the forward stroke, the pulse coupled to the DC motor has about 25 ^G / o turn-off time at the maximum infusion rate, which is selectable by switch 310. Due to the mechanical inertia, the Hotor continues to wire and generates a counter electromotive force that is proportional to the angular velocity of the armature. This voltage is sampled and stored by a speed feedback circuit to control transistor 300 and schedule the on-side of the pulses (pulse duration) to compensate for fluctuations in the load. In this manner, various fluids and syringes can be used without significantly affecting the calibration of thumbwheel 174.

During the forward stroke, transistor 265 is on, where he connects the terminal 270 to the supply voltage on the Line 275 connects. During the switch-off of the forward stroke pulse transistor 270 is off, transistor 268 is off and ground 250 is off the Hotor connection 262 is separated. The counter-electromotive force A resistor 335 and two series-connected diodes 336 and 337 are then connected to the Hotor connection, one Capacitance 340 coupled to ground 250. The capacity 340 charges to a potential that is the sum of the supply voltage and the voltage generated by the motor.

During the on-time of the forward stroke control, the transistor 270 is controlled in the conductive state so that the transistor 268 is controlled in the conductive state, and thereby the motor connection 262 approximately at ground potential.

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closes and diodes 356 and 337 reverse vo ^ annt. The charge above the capacity 340 now becomes this is used to control the base drive of the transistor 300 so that a turn-on time is proportional to the voltage above the capacity is set. A resistor 342 enables that the voltage across capacitance 340 drops slowly. Because the emitter of transistor 300. with its voltage is related to the food gliding, the current is hanging back electromotive through transistor 300 alone Power on the DC motor, so that the effect of supply voltage fluctuations is eliminated.

The control circuit further includes melxrera special circuits, which are described below,

Bubble detector

The bubble detector circuit includes bubble detector electrodes 212 and transistors 350 and 351. If a fluid with a conductivity equivalent to a salinity of 0.001 fo or more is present between electrodes 212 that are 6.3 mm apart, the resistance between them is on the order of 200 kOhms or less. This causes a current to flow from the Feed line 275 through the emitter base path of the Trara gate 350, through a V / resistor 352, for example with 10 kOhm, to an electrode 212 and from there through the fluid to the other electrode 212 in order to charge a capacitor 353, for example with 1 microfarad} the capacitor 353 is discharged through a diode 355 through the forward stroke control loop. The time constants are chosen so that capacitor 353 will never charge to more than 0.1 volts unless the drive stroke control circuit fails. If the forward stroke control circuit fails such that the full supply voltage would be applied to the motor 12o on the forward stroke, the capacitor 353 charges to the supply voltage and

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blocks transistor 350. This terminates operation. In this way, the patient is protected from excessive infusion rates that could otherwise be caused by a failure of critical parts in the circuit. The current flowing through the fluid is on the order of 10 Ilikroampdre oda? less, so he's no Risk of electrolysis or other dangers for the patient uit itself.

The current charging capacitor 353 causes a at least 200 times as large a current from the voltage source through the emitter-collector path of transistor 350 through a resistor 357 and into the base of transistor 351 flows. This will forward bias transistor 351 so that a current path to ground through the transistor 351 and a resistor 358 is created which is connected to the base of the transistor 269, so that a Control signal for transistors 269 and 265 flow can when transistors 269 and 265 through the reversing switch driver circuit s are switched on. If an air bubble or inclusion is present between the electrodes 212 is, the Stro:, vg is interrupted and the transistor 351 haunted. Therefore, the motor 120 stops on the forward stroke. The start switch 176 in the forward stroke control circuit is used to initiate this shutdown during the initial Override filling of the syringe.

By combining the base detector circuit and the placement of electrodes 212 and 220 in the two-way valve assembly 40, a fail-safe device is created which detects air leaks caused by a defect are caused in the purapen facility itself. The electrodes 212 (Pig. 4) are on the pressure side of the fluid channel between the two check valves 195. If the hollow electrodes 212 are not completely through the Plastic material that forms the wall of the valve duct,

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should be surrounded, as it can happen, for example, if the valve assembly falls down, air will pass through Opening generated, the air from the atmosphere in the flow channel 204 can enter. When the electrodes 212 into inlet 36 upstream of the check valve would be arranged, the furthest downstream could Electrode admit air leakage during a return stroke. When the air bubble passes your check valve 195 should it escape detection by the bubble detector circuit.

To connect such an occurrence are the electrodes arranged in an area which causes high pressure during a forward stroke. During the forward stroke is the Pressure in the channel 204 greater than the ataospheric pressure, so that an air passage opening next to one of the electrodes 212 only causes fluid to leak out of channel 204, but not an air bubble in the channel is produced. A low-pressure area is created during the return stroke is generated in the fluid passage 204 so that air enters the passage 204 from the atmosphere can. Regardless of the air leaking electrode 212, the bladder will move toward the pump continuation 203 upstream so that the j-'lase turns on the electrodes 212 must pass during the forward stroke. As a result, the air bubble is captured in the same way be like when the bubble is out of the fluid source would have been drawn in.

The bubble detector control circuit therefore serves the dual purpose Purpose of providing a safety device to prevent accidental passage of an air bubble, and further as a device to turn the pump unit automatically turn off when-dos go s aiii te fluid in the Solutionfioache is used up. At the end of the StröraungsKittel-SUfuhr vrii'd namely introduced air into the solution bottle

2 0 a 8 Ί 77 1 2 5 0

and pumped out through the valve device 40. When the air reaches the point where the two sensor electrodes 212 are located, the strobe path is interrupted and the operation of the motor ended, so that the pump device is switched off.

This circuit, which consists of transistors 370 and, responds to a drop in battery voltage, the switch-off time (pulse gap) of the pulses in the pre ~ to reduce downward stroke control. As already described, the return stroke is not controlled, whereby its speed changes with the voltage fluctuations. The time, which is lost on the return stroke is caught up again by accelerating the motor on the forward stroke.

The transistor 371 acts as an ideal diode and sets a reference voltage of about 0.7 YoIt at its collector, which is in series through a resistor 376 and a resistor 377 is coupled to a line, which in turn is connected to the positive potential via a switch 316 lying line 248 is coupled. Shunted with resistors 376 and 377 and transistor 371 a resistor 380 in series with the emitter of the transistor 370 and a resistor 382 in series with the collector of transistor 370 and ground 250. The collector of the Transistor 370 is directly coupled to the node between transistor 304 and capacitor 325. if As the battery supply voltage becomes lower, the current through resistor 380 changes linearly. This increases the collector voltage of transistor 370 is linear with a speed determined by the ratio of the resistor 380 to a resistor 382 and a Resistance 384 is determined which is in series between the

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Collectors of transistors 303 and 304 is connected. The voltage at the base of transistor 370 changes also, but with a reduced ratio.

I ¹ Ur the particular driven by the motor device, which was built, the circuit constants were selected so that the voltage at the collector of transistor 370 and therefore also to the transistor 304 with a drop of the battery voltage in a ratio of 1.5 became less, that is, a 0.1 volt change in battery voltage produced a 0.15 volt lower charge on capacitance 325. While this ratio provided the correct compensation, other ratios may be used for other loads driven by the motor. The range of the battery voltage compensation circuit is dimensioned so that the battery voltages can be tolerated, down to about 2 volts, a voltage drop of 33 i »altspricht of the full battery voltage of 3 volts.

For the circuit constants given above, a battery supply voltage of less than 2 volts means that the batteries must be replaced or recharged in order to maintain the precisely calibrated operation of the pump device. A low battery indicator circuit appears through the integrated NOT gates 390 and 391 for excitation an indicator lamp 293 for the low battery voltage is formed. When the supply voltage is above 2 volts, a is generated Voltage divider drawn by resistors 395 and 396 in Series connected between ground 250 and the feed line via switches 316 and line 348, one Voltage above 0.8 volts at the junction between resistors 395 and 396, causing HICHT gate 390 to saturate and the NOT gate 391 is disabled so that the Lamp 393 remains off. When the supply voltage drops below 2 volts, gate 390 is turned off, so that the gate 391 is turned on and thereby the indicator lamp 393 is energized. The indicator lamp 393 is on

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preferably under a window in the upper housing part the pump device so that it is available for the operating personnel is siciatable.

about the p rinse kd etector

.This circle v. ^It is formed by gates 400, 401 and a transistor 372, which are designed as integrated circuits. The iore 400 and 401 are connected in such a way that they form a bistable multivibrator. During liorraalbetrieb (no overpressure) the gate 401 is open and the transistor 372 is blocked. To ensure this condition is a capacitor 40? five times as large as a capacitor 306. When the control circuit is energized the first I-Ial, the capacitor 405 holds an input of the gate 400 at a low potential long enough that the bistable iultivibrator is set so that the gate 401 is saturated and the gate 400 is locked.

'.iev.n the. -jtrönunrsmittel reaches the electrode 22o, whereby an overpressure is announced, a current path is created from an input of the gate 400 ζυ of the supply voltage line 275 via a transistor 350 and the electrode 212, which is connected to the latter via the resistor 352 Base is connected, v / o when gate 400 is opened and gate 401 is locked. This turns on transistor "72, blocking transistor 551, which in turn opens the feed-in path for transistors 269 and 265. This stops the device on the forward stroke. The overpressure detector circuit can be reset by turning off the control circuit and is switched on again, whereby the capacitor 405 in turn opens the gate 401

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BATH

Bladder _una_Ü]) pressure indicator

This circuit consists of transistors 310 and 411, which control the excitation of a visual display device such as a light emitting diode 413. A light emitting diode is preferably used instead of an incandescent lamp because it consumes less power Has. When an air bubble or overpressure is sensed by the circuits described above, the transistor 351 is blocked. This in turn 'the transistor 410 is blocked, so that the node of the earth, which is between a resistor 415 and a diode 416 which is in series between the anode the light emitting diode 413 and the base of the transistor 411 is connected. The transistor 411 turns on this Way forward biased so that a current path for the light emitting diode 413 is through a resistor 420 and the collector-emitter junction of the conductive Transistor 412 is created to earth. The light-emitting diode 413 is located next to a precious stone lens which is in the Housing 170 is arranged to give a visual indication that the circuit is due to the sensing of a Has switched off air bubble or overpressure.

For some applications it may be desirable not to include all of the individual circuits described above, or to use various combinations of these circuits.

209817/1250

Claims (27)

Claims (1 .y device for pumping fluid, marked by positive displacement pump means (42,120) for displacing fluid "at a Movement of a piston (44), a reversible direct current motor (120) with an armature (121), which is in Vorwärtsnnd Reverse direction depending on the direction of the current flow through the motor (120) is movable, a gear, (122,126,130,132,134) which connects the armature (121) with the piston (44) to the piston by a forward stroke and to move a backward stroke to and fro during a forward movement or backward movement of the armature (121), and by a circuit device (FIG. 3) for supplying power to the motor (12o), the reversing devices (152,154; 265-270) to indicate the direction of the current flow periodically reverse by the motor (12O). 2. Device according to claim 1, characterized by a battery device (16o) for generating a DC voltage, whose amplitude decreases with aging and use of the battery, whereby the circuit device (FLg.3) is powered by the battery device (160), and by a compensation device (370,371), to maintain a fixed speed of rotation of the armature (121) while the amplitude of the DC voltage falls off. 3. Device according to claim 2, characterized in that the reversing device control devices (265,268), 209817/1250 which can be operated as gate circuits to generate electricity in one direction to the motor (120), and second control devices (266,267), which act as gate circuits are operable to lead the current in an opposite direction to the motor (12o) and that the compensation device (370,371) the duration of the actuation of the first control devices (265,268) in Increase depending on a drop in the amplitude of the DC voltage. 4. Device according to claim 1, characterized in that the circuit means includes a generator (300-304) for varying the pulse width of the coupled to the motor Having drive pulses and selection means (174,312) to different pulse widths for changing the movement speed of the anchor (221). 5. Device according to claim 1, characterized in that the reversing device has two switching elements (152,154) which are arranged at such points that correspond to the desired forward stroke and return stroke of the movement of the piston (44), a device (150) which can be moved by the transmission (122,126,130,132,134) around the switching elements (152,154) to be actuated during the movement of the piston, and control devices (265-270) which act on the actuation a switching element (152,154) respond to the current Reverse the direction of current to the motor (120). 6. Device according to claim 1, characterized in that the circuit means selecting means (174,312) for selecting the various pumping speeds, forward stroke means, responsive to the various speeds selected by the selection means (174,312), to change the amount of current delivered to the motor that flows in the forward direction, to change the armature (121) 209817/1250 move in forward direction au, and return lifting devices has to the amount of the reverse direction to the motor (12o) flowing current independently of the selection devices (174,312) to be set. 7. Device for pumping fluid with positive displacements for a system for transferring fluid from a fluid source to an outlet, in particular according to claim 1, characterized by a Purapen device (40,42,120) with an inlet port for receiving fluid from the fluid source (20), an outlet port corresponding to the outlet, and with fluid channel means connecting the inlet port and the outlet port, and a pump chamber in which a piston (44) is slidably disposed and having valve means to regulate the flow of fluid from the inlet mouth to the outlet mouth see below, when the slidable piston (44) is moved Mn- and fro, electrode means (212 x 22θ), the extend into the fluid duct assemblies (204) and connected to a Schaltui.a, and through a motor (120) for reciprocating the piston (44) through a cycle of movement, with safety devices (550,351; 400,401,372) are provided that are set to a predetermined Change in the circuit to change the movement response cycle. 8. Device according to claim 7, characterized in that the electrode means comprise two electrode elements (212) which are in contact with the fluid, wherein the circuit is completed by the fluid, and that the safety devices (350, 351) to the interruption of the circle by the presence of an air bubble between the electrode elements (212) respond in order to start the movement of the piston (44) 209817/1250 hold so that the passage of an air bubble to the Outlet is prevented. 9 «device according to claim 8, characterized in that the motor means for propelling the piston (44) to move the fluid in the pump chamber (72) to compress, and Rückhubeinriehtungen for driving the piston (44) to the volume of the Expand fluid in the pump chamber (72), and that the safety devices (350,351) switches off the forward stroke devices to prevent the movement of the piston (44) to end. 10. Device according to claim 9 »characterized in that the valve device acts in one direction Inlet valve element (36,195) between the inlet port and the pump chamber (72) and a unidirectional outlet valve element (46,195) between the outlet port and the pump chamber (72), and that the two electrode elements (212) in the fluid channel means (192) between the inlet valve element (36,195) and the outlet valve element (46,195). 11. The device according to claim 7, characterized in that to eliminate an overpressure condition, the Flussraittelkanäeinrichtung (192) has a fluid channel (204) with a fluid port opening to the fluid channel means is adjacent to fluid admit into the channel at a distance determined by the pressure of the flow device in the fluid channel arrangement is determined, and that the electrode device comprises an electrode element (220) which is shown in the channel (204) is arranged at such a distance that corresponds to an overpressure condition, wherein the Safety devices (400,401 ^ 372) respond to the fact that fluid with the electrode element (22o) to 209817/1250 2U4096 2U4096 Closing the circuit comes into contact to thereby to modify the cycle. 12. Device according to claim 11, characterized in that the fluid channel (204) has a closed end (217) opposite the fluid opening has to be a compressible Entrap gas between the closed end and the fluid admitted through the fluid port, that the electrode element (22o) from the compressible gas during the reciprocating movement of the piston (44) urag & en through the cycle of motion, where a Overpressure causes the fluid to compress the gas until the fluid contacts the electrode element (220) comes into contact. 13. A device for pumping positive displacement fluid having disposable parts after use; and in a portable infusion device for transferring fluid from a source of fluid to a Catheter is arranged, in particular according to claim 1, characterized by a self-contained direct current source (160), a disposable syringe (42) with a plunger (44), which is movable over a distance in order to circulate fluid in a cylinder (72) with a single fluid passage opening to displace a disposable valve assembly (40) with a pump mouth (203) which is detachable with the single opening is composed of an inlet port (36) connected to the fluid source for transfer of fluid is connected to the cylinder (72) and having an outlet port (46) connected to the catheter (21) is connected to the transfer of fluid to the catheter, a holder (90) that holds the syringe (42) and releasably holding the valve assembly (40) to be disposable after use with a patient; and by a motor device (120) which is supplied by the direct current source and a holding part (140) 209817/1250 reciprocated over the distance, the piston (44) being releasable from. the holding part (140) is held. 14. Set up after. Claim 13, characterized in that that the motor device is a direct current motor (120) for turning a gear, which the holding part (140) reciprocated, dialing devices (174,312) to select one of a variety of pump speeds, from a generator (300-304) for generating DC voltage pulses with different duty cycles, to select different pump speeds, and circuit means for coupling the DC voltage pulses to the DC voltage motor (120). 15. Device according to claim 14, characterized in that a Kompensationseinriclrfeung (370,371) for voltage fluctuations is provided which is responsive to a falling voltage at the DC voltage source (160) to the duty cycle of at least some of the DC voltage pulses to increase. 16. Apparatus according to claim 13, characterized _s that said motor means comprises a reversible DC motor (120) for starting, an armature shaft (121) in opposite directions, when a current of opposite polarity is coupled to the DC motor, a transmission (122,126,130,132,134) for converting the Rotary movement of the armature shaft (121) into a translational movement, which drives the holding part (140), and a circuit device (152,154,265-270) for periodically reversing the polarity of the current flowing from the DC voltage source (160) to the DC motor (120). 17. Device according to claim 13, characterized in that 209817/1250 the valve arrangement (40) a sensor device (212) for sensing the occurrence of an air bubble, and a safety device (350,351) responsive to the sensing an air bubble is responsive to the operation of the engine device to end. 18. Device according to claim 13, characterized in that overpressure devices (400,401,372) are provided to to be sensed when the pressure of the catheter (21) sensed * * given fluid a predetermined maximum value and that a display device (413) is actuated when the predetermined maximum is exceeded to provide an alarm indication. 19. Control circuit for supplying power to a DC motor from a DC voltage source with a DC supply voltage, the amplitude of which is subject to fluctuations, in particular for use in a device according to claim 1, characterized by gate steps (265-268) between the DC motor (12o) and de-- DC voltage source (160) are coupled and a drive pulse when actuated pass on to the power supply of the DC motor (12O), a generator (3OOt3O4) for periodic Actuation of the gate steps (265-268), whereupon these pass on drive pulses with a variable duty cycle, by a feedback device (340), which is based on a Change in the load of the DC motor (120) responds and then changes the duty cycle of the drive pulses, to maintain a desired constant speed, being the desired constant speed changes with the amplitude of the DC supply voltage, and by a compensation device (370,371) »um the duty cycle of the drive pulses in the opposite direction as a function of the amplitude fluctuations to change in the DC supply voltage. 209817/1250 20. Control circuit according to claim 19 »characterized in that the feedback device is a memory device (340) to store the counter electromotive force on the electric motor when the door steps are not "are actuated and that the generator (300) responds to the stored counter electromotive force at the time the periodic actuation of the door steps. 21. Control circuit according to claim 20, characterized in that the memory device has a capacitor (340) and Having diodes (336,337) connected between the capacitor (340) and the gate stages (365,368), wherein the diodes (336, 337) are polarized in such a way that they block the flow of current to the capacitor (340) when the "gate stages" are actuated are. 22. Control circuit according to claim 20, characterized in that the memory device has a first device for Storage of the sum of the electromotive force with the DC supply voltage and a subtraction device having that with the first device and the DC voltage source is coupled to generate a feedback signal that is only equal to the back electromotive Force is, and that the generator (300) on the feedback signal responds to change the time of the periodic actuation of the gate circuits (265,268). 23. Control circuit according to claim 19, characterized in that that the generator is a multivibrator (300-304) with a first stage, which is used to control the time of the periodic Actuation of the gate steps can be reset, and has a second step that controls the time of the periodic shutdown of the gate stages can be reset, and that the feedback device resets a of the stages and the compensation device controls the resetting of the other stage. 209817/1250 24. Ventilation arrangement that guides a fluid flow, in which the fluid is electrically conductive and the sum monitoring of a property of the fluid serves, in particular for use in a device according to claim 1, characterized by a Fluid channel means (192) that facilitate the flow of fluid contains, a unidirectional valve device (36,195; 46,195) in the channel device lies and. movement of the flow means is only allowed in one direction, and by two electrode devices (212,220), which are arranged in the channel device (192), and have lugs that are connected to a external circuit are connectable, with the presence or absence of flow medium / between the Electrode pair (212) indicates the property. 25. Valve arrangement nacii claim 24, characterized in that that the fluid channel means (192) is a fluid channel (204) having a fluid opening adjacent the fluid channel means to Admitting fluid into the channel (204) at a distance; which is determined by the pressure of the fluid in the Ströaungsraittelkanaleinrichtung that at least one electrode (220) of the pair of electrodes in the channel (204) at a predetermined distance from the Ströramittelöffmmg is arranged, so cfeß the presence of the fluid at the latter electrode (220) indicates a predetermined pressure condition. 26. Valve arrangement according to claim 25, characterized in that the fluid channel (204) has a closed end (217) opposite the fluid opening (2o2) to a compressible gas between the closed end and that admitted through the fluid opening (202) To enclose fluid and that the latter electrode (220) is surrounded by the compressible gas, 209817/1250 > AQ9_6 - 34 - when the pressure of the fluid in the air duct device (192) is less than the predetermined printing condition. 27. Valve arrangement according to claim 24, characterized in that the fluid channel device (192) has an inlet channel with an inlet opening (36) and an opening next to an outlet channel with an outlet opening (46) and a pump opening (203), dai3 the in one Direction-acting valve device has an inlet valve (36) (195) in the inlet channel in order to allow only a movement of the outlet channel directed towards the outlet channel, and an outlet valve (46 _and 195) in the outlet channel in order to only permit a movement of the flow channel to the outlet port (46) and that the pair of electrodes (212) lies between the inlet valve (36,195) and the outlet valve (46; 195), v / o "indicates an air bubble in the absence of fluid between the pair of electrodes (212). 2098T7 / 1250