JPH0412989B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pump device. In particular, the present invention
Concerning metered-dose infusion pumps for IV (intravenous) solution delivery.

(Prior Art and its Problems) Due to health considerations, various efforts have been made regarding the supply of IV solutions.

For a long time, IV solutions were delivered solely by gravity. The feed rate is measured by counting the number of drops per minute. In many instances,
This method is unsatisfactory. Droplet size is directly proportional to surface tension and is influenced by solution type, viscosity, temperature, etc. The size of a water droplet is then influenced by the speed at which the water droplet is formed.

The velocity of water droplets (formation) is influenced by tube and needle limitations and gravity. If the tube is partially occluded, the drop rate will be reduced or the IV
As the liquid supply decreases, the liquid pressure decreases and the drip rate decreases. Therefore, in many instances, the variability of droplet size and drop rate, both of which are outside the operator's control, make this method of delivering IV fluids unsatisfactory. I have to.

Improvements have been made to use electronic drop counters in conjunction with controllers or peristaltic pumps. A combination of electronic drop counters can control the drop rate, but not the drop size.
Another drawback is that the dropping rate cannot be controlled when the back pressure increases to exceed the liquid delivery pressure.

The combination of an electronic drop counter and a peristaltic pump increases the delivery pressure, but the metering method lacks precision.

In order to improve the metering method, a displacement pump will be adopted. This allows for much more precise control of IV fluid flow rate than older IV controls that rely on gravity. In addition to metering fluid, these pumps can provide positive pressure to fluid or IV pump tubing. Displacement pumps may be peristaltic (as described in U.S. Pat. No. 3,737,251 to Berman et al.), piston-cylinder (as described in U.S. Pat. No. 3,985,133 to Zienkins et al.), or pulsed (as described in U.S. Pat.
3874826) etc.

Peristaltic pumps, which are improvements over conventional technology, have a number of disadvantages. First of all, peristalsis has friction that interferes with the blood supply, causing blood cells to break down. Second, peristalsis involves tensioning of the elastomeric material, which can entrain air into the IV fluid. Third, tensioning elastomeric materials in a peristaltic state is not an efficient use of energy.

Due to the mobility of the sick person and the potential for loss of power,
It is necessary to drive the pump with a battery,
It is therefore desirable that the pump be able to achieve maximum efficiency.

Although prior art piston-cylinder pumps provide accurate metering and positive pressure, they also have some drawbacks. First, the pump chamber is disposable and inexpensive to manufacture, as IV therapy requires the pump to remain sterile and the cost does not allow for cleaning and sterilization after each use. There must be. This is difficult to achieve with conventional piston-cylinder pumps.

To reduce manufacturing costs, some conventional pumps use only one cylinder and two valves. According to this, the feed cycle uses two parts: filling and emptying. Therefore, IV therapy is interrupted during the fill period of the delivery cycle. Second, some conventional piston-cylinder pumps require sterile seals on the sliding surfaces;
It is difficult to meet its reliability requirements. Third
Furthermore, friction in piston-cylinder pumps causes a reduction in efficiency.

Pulse pumps provide continuous pulsed flow, but they also have important disadvantages. First, the independent control valves of this type of pump are complex, making the disposable pump chamber expensive. Second, spring forces and pulsing effects on elastomeric materials are not suitable for efficient operation.

U.S. Pat. No. 3,809,507 to Bagley describes a pump that is not specifically intended for use in IV therapy, but which provides a continuous steady flow. The valves used in this pump are located either in the working part or in the fixed part and are connected by flexible tubing. This does not lend itself to economical disposable pump chambers, such as those required in IV therapy applications. Additionally, without biasing or moving the valve,
With the pump stopped, fluid supply can continue (by so-called siphon action). This is not a safe condition for IV treatment.

Another common problem with conventional IV devices is that they do not provide any means to sense and select backpressure and thereby sound an alarm. Patients undergoing dialysis are therefore subject to the maximum backpressure that the pump can provide. This sometimes exceeds safety limits for patient application.

(Means and effects for solving the problems) The present invention provides a compact,
About accurate, reliable and economical pumps.

The pump includes a disposable pump chamber and a pump housing. The disposable pump chamber has an inlet and an outlet and first and second flexible rolling diaphragm pump chambers.

The pump housing includes first and second flexible cylindrical diaphragm pump chambers containing first and second flexible cylindrical diaphragm pump chambers.
It has a second cylinder. The first and second pistons are movable within the first and second cylinders, respectively. First and second valve devices are provided to control the flow of solution between the inlet and outlet of the disposable pump chamber. The first valve controls the flow of liquid between the inlet and the first flexible cylindrical diaphragm pump chamber. A second valve controls fluid flow between the first and second flexible cylindrical diaphragm pump chambers.

The drive device changes the volumes of the first and second flexible cylindrical diaphragm pump chambers by causing relative movement of the first cylinder and the first piston, and of the second cylinder and the second piston, respectively. .

By appropriate selection of the volumes of the first and second flexible cylindrical diaphragms and the ratio of the drives for changing the volumes, pulsation-free evacuation (of the invention) is achieved.

For application to IV supply devices, it is important that siphon action does not occur when the pump stops for some reason.

In a preferred embodiment, the present invention, first and second
The valves are controlled such that at least one valve is always closed. Safe operation of this pump is thereby achieved.

The invention also includes a third flexible diaphragm chamber between the outlet of the disposable pump chamber and the second flexible cylindrical diaphragm pump chamber. Back pressure is sensed by movement of this third flexible cylindrical diaphragm pump chamber.

In the example of use in IV fluid delivery, it is important to detect the presence of air bubbles in the pumped fluid.

The invention also provides that when liquid is pumped between two different points in the disposable pump chamber,
It has an anti-bubble system by measuring the dielectric constant. As the bubble passes through the disposable pump chamber, a change in dielectric constant between two points is detected and an alarm is issued.

(Example) FIGS. 1 and 2 show an overall view of the IV pump of the present invention. As depicted in the figure, IV
The pump does not include an envelope that completely encloses the pump, as does the associated control circuitry. The outer case has been removed and the control circuitry has not been shown to simplify the drawing.

The pump shown in FIGS. 1 and 2 includes a disposable pump chamber 10 and a housing 12. The pump shown in FIGS.
An inlet tube 14 and an outlet tube 16 are connected to both ends of the disposable pump chamber 10.
Introductory tube 14 is a container for IV fluid (not shown)
A drain tube 16 supplies IV fluid from the pump to a patient (not shown).

In embodiments of the invention, the IV pump includes a first
It is better to place it vertically rather than horizontally as shown in FIGS. In a vertical arrangement, the inlet tube 14 for entering the pump is provided at the bottom and the outlet tube for leading out of the pump is provided at the top. This pump arrangement is preferred because it prevents air from building up within the fluid passageway during initial installation and cleaning of the IV system.

IV therapy requires that the pump be kept sterile. Therefore, the disposable pump chamber 10 is used for only one IV use and then discarded. In contrast, the pump housing 12 does not come into direct contact with the IV fluid. And used again and again.

Pump housing 12 has a top cover 18 that can be opened and closed, as shown in FIG. 2, to allow insertion and removal of disposable pump chamber 10.

When the pivoted latch 19 or side cover is in the closed position, the pump remains in operation. As shown in FIG. 2, when the side cover 19 is pulled downward, the top cover 18 is opened via the stopper member 20. As shown in FIG. 2, the stop member 20 is configured such that its hole 20A engages with the stop pin 21. As shown in FIG.

As shown in FIGS. 1 and 2, the pump housing 12 has a diaphragm housing 22 that, in conjunction with the top cover 18, serves to receive and retain a disposable pump chamber. Below the diaphragm accommodating part 22, the motor of the IV pump,
A cam housing 23 is provided which supports the camshaft, valve and piston rod.

In the embodiment of the invention, the diaphragm housing portion 22 is mounted on the cam housing via a spring. Therefore, when both the side cover 19 and the stop member 20 are opened, the diaphragm housing portion 22 is removed from the cam housing 23.
As will be described in detail below, the above configuration allows all pistons, valves, etc. to be completely removed from the top of the diaphragm housing 22. As a result, the disposable pump chamber 10 is adapted to be inserted regardless of the position of the piston and valve in the pump's delivery cycle.

As shown in FIG. 2, disposable pump chamber 10 has three diaphragm chambers 24, 26 and 28 projecting downwardly from its lower surface.
has. These chambers 24, 26 are the first and second pump chambers, while chamber 28 connects chamber 1 through exhaust tube 16.
This is a chamber for pressure detection that moves in response to back pressure when fluid flows out from zero.

In normal use, IV fluids are pumped into the first pump chamber (flexible cylindrical diaphragm chamber) 2
4 through an introduction tube 14. Then,
a second pump chamber (cylindrical diaphragm chamber) 26 (cylindrical diaphragm chamber), a sensing chamber 28 and a discharge tube 16;
from there to the patient.

In embodiments of the present invention, the first and second pump chambers 24, 26 are configured such that the flow of IV fluid exiting the outlet tube 16 is essentially non-pulsating and has a precisely controlled outflow rate. Driven under condition.

Diaphragm housing 22 includes first, second and third cylinders 32, 34 and 36 each receiving a downwardly projecting cylindrical diaphragm chamber 24, 26, 28 of disposable pump chamber 10. The first piston 38 is movable within the first cylinder 32 so that the volume of the first pump chamber 24 can be changed. Similarly, the second piston 40 can move within the second cylinder 34 so that the volume of the second pump chamber 26 can be changed. Both the first and second pistons 38, 40 are driven by motors, as described below. Unlike the first and second pistons 38, 40, the third piston 42 is
It is not driven by a motor but moves within the third cylinder 36 in response to the pressure of the liquid in the pressure sensing chamber 28.

The first and second valves 44 and 46 are similarly provided within the diaphragm housing 22 . A first valve 44 is provided between the end of the inlet tube 14 and the first pump chamber 24 . First valve 44
is driven by a motor. When it is at the top, it blocks the flexible section between the introduction tube 14 of the disposable pump chamber 10 and the first pump chamber 24 (first flexible passage section). The first valve 44 also allows fluid flow from the inlet tube 14 to the first pump chamber 24 when it is at its lowest position.

Similarly, a second valve 46 is provided between the first pump chamber 24 and the second pump chamber 26. The second valve 46 is also motor driven and, when it is in the uppermost position, the flexible portion of the disposable pump chamber 10 between the first pump chamber 24 and the second pump chamber 26 (the second (flexible passage section). Also, when it is at the lowest position, the second valve 46
is from the first pump chamber to the second pump chamber 2.
Allowing fluid flow to 6.

As also shown in FIG.
0 are each inserted into the alignment holes 52, 54 of the disposable pump chamber 10. Alignment pins 48, 50, along with alignment holes 52, 54, ensure that disposable pump chamber 10 can be inserted into pump housing 12 quickly and oriented in only one direction. The downwardly projecting cylindrical diaphragm chambers 24, 26 and 28 also have alignment portions. Therefore, the pump can be assembled without the alignment pins 48,50.

In the embodiment of FIG. 2, alignment holes 52 are essentially round holes and holes 54 are elongated holes. With this configuration, alignment pin 48 and alignment hole 52 guide the positioning of disposable pump chamber 10 such that hole 52 is positioned over alignment pin 48 prior to pin 50 being placed in hole 54.

Another important feature of the invention is the ability to detect the presence of air bubbles in IV fluids. Air bubbles are dangerous to patients receiving IV therapy, and it is necessary to have an alarm device that indicates the presence of air bubbles in the fluid.

As shown in FIG.
Contains 58. Terminals 60 and 62 are connected to electrodes 56 and 58. Connected to the diaphragm housing 22 is a common electrode 64 . bolts 66 and 66a
secures the common electrode 64 to the diaphragm housing 22 and provides electrical connection to the common electrode 64.

An electrical conductor that can detect the presence of air bubbles passing through the disposable pump chamber 10 by measuring the capacitance between the first electrode 56 and the common electrode 64 and the capacitance between the second electrode 58 and the common electrode 64. A circuit (not shown) connects common electrodes 64 to opposing sides of the disposable pump chamber 10.
and terminals 60, 62, 66 to detect the difference in dielectric constant between electrodes 56, 58. When a single bubble passes between the first electrode 56 and the common electrode 64, the electrical circuit becomes unbalanced, which causes an alarm to sound.

In a preferred embodiment of the invention, top cover 18 is made of a transparent, optical plastic material, such as Plexiglas or similar acrylic. Because the top cover 18 is transparent, the physician can see if there are air bubbles in the fluid flowing through the pump.

This ensures that all air has been purged from the system between assembly and disassembly and prior to connecting the IV device to the patient.
Because a doctor has to confirm,
It's important. The present invention allows the clinician to visualize the fluid being pumped even during initial assembly.

As best shown in FIG. 2, below the latch pin 21 is a switch 68. When top cover 18 is closed and side cover 19 is in the closed position (as shown in FIG. 1), arm 70 of switch 68 engages the inner surface of side cover 19, thereby causing switch 68 to close. Closed.

An electrical circuit (not shown) senses whether switch 68 is closed and thereby determines whether the pump is ready for operation. The pump is only ready for operation when switch 68 is closed. This prevents operation of the pump when the diaphragm housing 22 is placed in the operating position on the cam housing 23 and the top cover 18 is not securely closed.

The leaf spring 72 is used to apply a small pressure to the liquid passageway of the disposable pump chamber 10 to prevent negative pressure from the exhaust tube 16 side. As a result, even if negative pressure acts on the discharge portion of the disposable pump chamber 10, the first and second pump chambers 24, 26 and the pressure sensing chamber 28 will not collapse under the effect of the negative pressure. The pressure from the spring is applied to the disposable pump chamber 1.
It is sufficient to overcome the tiny compliance of the zero liquid path. The negative pressure ensures that the liquid passage is closed. Only a small amount of pressure is required to overcome the force of leaf spring 72.

Operation of the IV pump of the present invention is typically performed as follows. When the first piston 38 moves downward,
These pistons 38 and 40 are driven so that the second piston 40 moves upwardly. Similarly,
When the first piston 38 moves upward, the second piston 40 moves downward. At the same time, the first and second valves 44 and 46 are driven so that one of the two valves is always closed. When the first piston 38 moves downward, the first valve 44 goes down and the second valve 46 goes up. Conversely, when the first piston 38 moves upward, the first valve 4
4 is in its highest position, and the second valve 46 is in its lowest position.

For convenience of explanation, assume that a typical feed cycle begins with the first piston 38 and first valve 44 at the top and the second piston 40 and second valve 46 at the bottom. . First, close the second valve 46.

Next, the first valve 44 moves downward to open. The first piston 38 then moves downward, thereby increasing the volume of the first pump chamber 24. The downward movement of the first piston 38 causes fluid to be drawn from the reservoir through the inlet tube 14 and into the first pump chamber 24 through the open first valve 44 .

As the first pump chamber 24 becomes full, the second piston 40 moves upwardly, thereby decreasing the volume of the second pump chamber 26 and causing the second pump chamber 24 to fill up.
Fluid is delivered from pump chamber 26 through exhaust tube 16 to the patient.

To stop the flow of fluid from the reservoir to the first chamber 24 when the first piston 38 reaches its lowest position and the second piston 40 reaches its highest position, the first
Valve 44 is moved upwards. Second valve 46
is then moved downwardly to allow fluid to flow from the first pump chamber 24 to the second pump chamber 26. After the two valves have moved, the first
Piston 38 begins to move upwardly, thereby decreasing the volume of first pump chamber 24, while at the same time second piston 40 moves downwardly, increasing the volume of second pump chamber 26.

In a preferred embodiment, the decreasing volume of the first pump chamber 24 is greater than the increasing volume of the second pump chamber 26. As a result, a portion of the fluid delivered from the first pump chamber is delivered through the exhaust tube 16 to the patient.

In the embodiment, each pump chamber 24 and 26
The cross-sectional area of and the moving speed of each piston 38, 40 are:
The amount of fluid being pumped through the discharge tube 16 is selected to be substantially equal when fluid is being pumped from the first pump chamber 24 and when fluid is being pumped from the second pump chamber 26. As a result, substantially pulsation-free fluid flow is produced with only two feed pump chambers and two valves.

When the first piston 38 reaches the top position and the second piston 40 reaches the bottom position, the feed cycle ends and the next cycle begins.

During the feeding operation, the pressure sensing chamber, i.e.
The volume of the chamber 28 varies depending on the back pressure from the patient and the evacuation tube. A third piston 42 contacting the bottom of the third chamber moves up and down in response to changes in fluid pressure within the third chamber 28 . Electrical contacts are connected to the third piston 42 .
The state of the contact (depending on the open or closed state) then indicates whether the backpressure exceeds one or more of the setpoints. An alarm sounds when each set value is exceeded.

During pump operation, the dielectric constant between the first and second electrodes 56, 58 and the common electrode 64 is detected. If a single air bubble passes through disposable pump chamber 10, this air bubble will pass between electrodes 56 and 6.
4, and the dielectric constant difference between electrodes 58 and 64.

3A, 3B, 3C and 4-6 details of the disposable pump chamber are shown. 3rd A~
Figure 3C is a top, side and bottom view;
Figures 1 to 6 are cross-sectional views taken at different positions.

In an embodiment of the invention, the disposable pump chamber 10 consists of two members: an upper member 10a and a lower member 10b. These parts are preferably made from a flexible plastic material that can be heat-sealed. In one preferred example, both the upper member 10a and the lower member 10b are made of vinyl resin.

Both the upper member 10a and the lower member 10b are vacuum formed or blow molded to form the passageway of the disposable pump chamber 10 and each pump chamber.

The upper member 10a is made of a flat sheet except for a raised portion 80a provided in the longitudinal direction over the entire length of the upper part. Rising ivy part 8
0a forms the upper half of the main channel that carries fluid from the inlet tube 14 at one end of the disposable chamber 10 to the outlet tube 16 at the other end. Introduction tube 1
4 and the diameter of the discharge tube 16 are smaller than the diameter of the member 80a.

The introduction end of the upper member 10a is an introduction part 82a,
This inner diameter is approximately the same as the outer diameter of the introduction tube 14. The main flow path 80a connected to the introduction part 82a is
A tapered portion 84a has a gently sloping transition from the introduction portion 82a to the main channel 80a.

The other end of the upper member 10a is a discharge portion 86a and a tapered portion 88a. The discharge portion 86a has the same inner diameter as the outer diameter of the discharge tube. The tapered portion 88a extends from the main flow path 80a to the discharge portion 8.
It changes gradually towards 6a.

Lower member 10b of disposable pump chamber 10
has a similar main flow path 80b, introduction section 82b, tapered section 84b, discharge section 86b, and tapered section 88b. Also formed in the lower member 10b and projecting downwardly are flexible cylindrical first and second pump chambers 24, 26 and a pressure sensing chamber 28.

The upper member 10a needs to be flexible enough to be closed by the leaf springs 72. The lower member 10b includes first and second pump chambers 24, 2.
6, and the pressure sensing chamber 28 must be flexible enough to allow movement. In addition to this, the first
The valve 44 (shown in FIG. 2) is connected to the tapered portion 84.
b and the first pump chamber 24
b can be crushed, and the second valve 46 is
It must be flexible enough to allow the portion of the main flow path 80b between the first and second pump chambers 24, 26 to be collapsed as well.

As mentioned earlier, the upper member and the lower member 10a, 10
b is a plastic material that can be easily sealed by heat sealing. Components 10a and 10b are heat sealed during molding or in a subsequent step. The mating surfaces of parts 10a and 10b are of a low melting point material, thereby facilitating the heat sealing process. The inlet tube 14 and the outlet tube 16 are preferably made of transparent material and are connected to the upper and lower members 10a, 10b.
Made by heat sealing.

Heat sealing is performed on the upper and lower members 10a and 10.
Although one adhesive means is used to connect the inlet and outlet tubes 14 and 16, other adhesive means may include ultrasonic adhesive, radio frequency (r) welding, solvent adhesive, or other adhesive means.

In one embodiment, disposable pump chamber 10 is made by blow molding. In that case,
The upper member 10a and the lower member 10b each have a tube 14,
16 and are heat sealed together in the molding process. The advantage of blow molding is that it avoids any problems that may occur using other methods when attempting to combine separately molded upper and lower members 10a and 10b.

Apart from this, the upper member 10a and the lower member 10b may be vacuum-formed separately. In this case, a mold with many recesses is used for the production of a molded plastic plate containing many of the same parts (such as 10a and 10b).
The inlet and outlet tubes 14 and 16 are then placed in position. A sheet with the same number of other members is then placed over the first sheet and tube, and then members 10a, 10b are heat sealed together.

Each pump chamber is then individually cut using a punch or die-cut type cutter. At the same time, the positioning holes 2 and 54 are
A hole of the desired size and shape is punched. In this way, a large number of disposable pump chambers 10 are manufactured simultaneously.

7-13 show various portions of the pump housing 12 from different angles.
FIG. 7 is a cross-sectional view of the pump housing 12 with the disposable pump chamber 10 inserted and the top cover 18 closed in an operative state.
The pump is shown at the beginning of a pumping cycle.

As shown in FIG. 7, the diaphragm housing portion 22 is placed on the cam housing 23. As shown in FIG. The components are then made of low friction materials such as Delrin, or materials such as ABS plastic with linear pairings used to reduce drag on valves and piston rods. The cam housing 23 is fixed to the mounting plate 92 at its base portion.

A motor 94 is supported by the cam housing 23 . The motor is preferably a step motor. Of course, other types of motors may be used, but step motors are particularly suited to being controlled by digital circuitry, such as a microcomputer control circuit, and are preferred due to their digital nature.

Motor 94 drives camshaft 96 . The camshaft 96 includes four cams 98, 100,
102 and 104 are provided. Cam 98 is
driving the first valve 44 via the rod 108;
Controls opening and closing of the first flexible passage section. The lower end of this rod engages over cam 98 and extends through shaft 109 of cam housing 23. First valve 44 is resiliently mounted to facilitate insertion of disposable pump chamber 10 into pump housing 12 .

The cam 100, via a rod 110 extending in a shaft 111 passing through the cam housing 23, drives the first piston 38, thereby changing the volume of the first pump chamber 24.
The lower end of the rod 110 engages over the cam 100, and its upper end is threaded to accommodate the attachment of the first piston 38. The mounting relationship between the rod 110 and the first piston 38 is as follows:
00 to the upper end of the first piston 38, thereby relaxing the requirements for tight tolerances.

The second valve 46 is connected to the cam 1 via the rod 114.
02 to control opening and closing of the second flexible passage section. The rod 114 has a rounded lower end that engages the surface of the cam 102 and passes through a shaft 115 within the cam housing 23. The second valve 46 is also resiliently mounted to facilitate mounting of the disposable pump chamber 10 into the pump housing 12.

The cam 104 is connected to the second cam via a rod 116 passing through a shaft 117 within the cam housing 23.
The piston 40 is driven, thereby changing the volume of the second pump chamber 26. Rod 116
The lower end of the rod 116 is rounded to engage the surface of the cam 104, and the upper end of the rod 116
It is adapted to be connected to a piston 40.

Therefore, the cams 98, 102 and the rod 1
08 and 114 constitute valve control means, and cams 100 and 104 and rods 110 and 116 constitute pump chamber drive means.

4 rods 108, 110, 114 and 1
Each of the 16 has a small spring 108a, 110a, 114a and 116a near the lower end of the rod. These springs are relatively weak springs, but are used to keep the rod in constant contact with each cam.

This configuration is useful when the pump is placed vertically (i.e., the rods 108,
This is particularly important when 110, 114 and 116 are normally horizontal). Springs 108a, 110a, 114a and 116a are made as weak as possible. For this reason, only a very small amount of energy is required to counteract the force of the spring when the pistons and valves are actuated.

The drive system for the first and second pistons 38, 40 and the first and second valves 44, 46 has important advantages. That is, the motor 94 is connected to the camshaft 96
Drive in one direction only. Reverse rotation of the drive motor is not required for the desired feed motion.

In addition, each pump chamber 24, 26 of the disposable pump chamber 10 is a cylindrical diaphragm-type chamber, and the first and second cylinders 3
2, 34, and their associated rods and cam riders. This makes it possible to reduce manufacturing costs and, on the one hand, achieve the required precision of the delivery rate (speed).

An encoder wheel 118 is connected to the camshaft 96 in FIG. This is a commonly used encoder wheel that has grooves at predetermined intervals near its periphery. Encoder sensor assembly 120 is provided on the back side of cam housing 23 and is positioned to sense the groove of encoder wheel 118.

Encoder assembly 120 has a light source (not shown) placed on one side of encoder wheel 118 and a light sensor (not shown) on the other side. Each time the slot in the encoder wheel 118 is crossed, light can pass from the light source to the light sensor and the encoder assembly 120
generates an electrical pulse indicating the presence of a groove in encoder wheel 118.

Figures 8 and 9 show encoder assembly 1.
20 details are shown. As shown in FIGS. 8 and 9, the encoder assembly 120 is provided on a flange 121 and screwed to the back surface of the cam housing 23.

The purpose of encoder wheel 118 and encoder assembly 120 is to directly indicate that camshaft 96 is rotating. In embodiments of the invention, a control circuit (not shown) monitors the output of encoder assembly (sensor) 120. If a change in the output of encoder assembly 120 does not occur at predetermined time intervals, an alarm will sound and pumping will cease.

This detection directly indicates whether the camshaft 96 is rotating or not, and furthermore, whether the pump is performing its function. The use of encoder wheel 118 and encoder assembly 120 is used to indicate this accident condition.

As shown in FIG. 7, the cams 98, 100,
Each of 102 and 104 has an alignment hole 98a, 1
00a, 102a and 104a.
Similarly, the encoder wheel 118 has alignment holes 118
It has a. The cam housing 23 has an alignment hole 23
A is provided. This hole 23a is an alignment hole 98
a, 100a, 102a, 104a and 118
a is used to perform the initial alignment of the cam.

Pass through the hole 23a and connect each hole with a pin (not shown).
All cams are aligned in the pump's initial assembled condition. The cam and encoder wheel are then secured in place on the camshaft 96 by a set screw (not shown). In this arrangement, the camshaft 96 is inserted,
This is completed by fixing the cam and encoder wheel.

Also shown in FIG. 7 is a back pressure sensing assembly. This consists of the third piston 42, the third cylinder 36 and the pressure sensing chamber 28 of the disposable pump chamber 10. As shown in FIGS. 7 and 10, the third piston 42 is connected to the shaft 12 in the cam housing 23.
It extends through 2.

A spring 12 is provided at the bottom of the third piston 42.
A terminal 124 for receiving the upper end of 6 is coupled thereto. The other end of spring 126 engages the top of intermediate member 128 . As can be seen, the pressure of the liquid in the pressure sensing chamber 28 causes the spring 12 to
6, the third piston 42 is urged upwardly by
It acts to push down.

As best seen in FIG. 10, an extension of terminal 124 is contact arm 130. 1st and 2nd
Contacts 132 and 134 are connected to the cam housing 2.
3, and is placed in two positions in the vertical direction. In this arrangement, spring 126 is
Sufficient pressure is applied to the piston 42 so that the contact arm 130 makes physical and electrical contact with the underside of the upper first contact 132 . Electrical connection to the contact arm 130 is made by a wire (not shown) connected to the terminal 124, and electrical connection to the first contact 132 is made by a wire (not shown) connected to the terminal 124.
32 and the screw 136 by an electric wire (not shown). The third piston 42, spring 126, terminal 124, contact arm 130, etc. constitute a pressure sensing means for sensing the pressure within the pressure sensing chamber.

While the pressure within the pressure sensing chamber 28 is not sufficient to overcome the elastic force of the spring 126 and the contact arm 130 and first contact 132 are in contact, the back pressure is within acceptable limits. While fluid from the pressure sensing chamber 28 flows directly to the drainage tube 16 that connects to the IV needle, the pressure in the pressure sensing chamber 28 is directly related to the patient delivery pressure. If the actual pressure (which is determined by the position of the spring 126, the mounting member 128 and the first contact 132) is exceeded, this causes the third piston 42 to move downwardly, causing the contact arm 130 and the first contact 132
When released, the electrical contact is broken and the alarm sounds.

In an embodiment of the invention, the lower second contact 134 is provided below the upper first contact 132 . When the pressure becomes higher and reaches a second set pressure, the contact arm 130 engages the upper end of the second contact 134. This is detected electrically and generates a second alarm indicating a second high pressure. An electric wire (not shown) is connected between the screw 138 and the second contact 134. An electrical control circuit (not shown) allows the operator to select which pressure limit (high or low) will activate the alarm.

FIG. 11 is a plan view of the cam housing 23, and FIG. 12 is a detailed view of the first contact 132. These two figures show the back pressure sensing mechanism of the present invention. As shown in FIG. 11, cam housing 23 has a narrow slot in which contact arm 130 moves.

FIG. 12 is a front view of the first contact 132, in which a rectangular metal plate has two long holes 142 and 144. The elongated holes 142 and 144 are designed to enable adjustment of the first contact 132, which is a plate, in the vertical direction.
The pressure for releasing contact between contact 132 and contact arm 130 can be adjusted. Similarly, the lower second contact 134 has an elongated hole that allows its position to be adjusted.

The back pressure detection mechanism of the present invention is inexpensive, has a simple configuration, and is reliable. This allows adjustment of two pressure ranges within which the alarm will sound.
Therefore, the present invention allows a range of backpressures to be selected at which an alarm will sound, such that the patient receiving dialysis is not exposed to the maximum backpressure that the pump can provide.

This has been a continuing problem from older pumps because the pump's maximum backpressure sometimes exceeded safety limits for a particular patient or device.

Although pistons, springs, contact arms, and contacts were used in the illustrated implementation, other means of sensing movement of the pressure sensing chamber 28 that are dependent on backpressure may be used as well. For example, a semiconductor or wire strain gauge may be used in place of the third piston 42 to detect pressure. However, the illustrated arrangement is cheaper, simpler, more reliable, and easier to adjust.

FIG. 11 is a plan view of the cam housing 23 and also shows the grooves 150 provided around each opening of the cam housing 23. These grooves collect fluid that somehow escapes from the disposable pump chamber 10 and collect it in the housing 23.
Prevent fluid from entering the sliding parts between the shaft and each rod.

Switch 68 and switch arm 70 are shown in more detail in FIGS. 11 and 13. The switch arm 70 engages the inner surface of the side cover 19 when all parts of the pump are installed. This is activated when switch 68 is closed, indicating that the pump is in operation. Switch 68 is attached to flange 152 coupled to cam housing 23.

FIG. 14 is a plan view of the diaphragm housing portion 22. FIG. 14, in conjunction with FIG. 2, shows a bubble sensing member used to detect air bubbles within the disposable pump chamber 10. This bubble detection member consists of first and second electrodes 56 and 58 provided on the lower surface of the upper cover 18. terminal 6
0 and 62 are in electrical contact with each of the first and second electrodes 56 and 58.

The common electrode 64 is provided on the upper surface of the diaphragm housing portion 22 and is held by screws 66 and 66a. The width of the common electrode 64 is larger than the width of the first electrode 56 or the second electrode 58, and the common electrode 64 is attached so as to directly oppose the first and second electrodes 56, 58. Discharge tube 16
The first and second electrodes 56 and 58 and the common electrode 64
placed between.

An electrical circuit (not shown) connected to the terminals 60, 62 and 66 connects the first electrode 56 and the common electrode 6.
4 and a second capacitor formed by the second electrode 58 and the common electrode 64 are detected. When a bubble reaches the first capacitor, the electrical circuit becomes unbalanced, indicating the presence of a bubble. This unbalanced state is also used to trigger an alarm.

The bubble detector shown in the drawings is simple and inexpensive and can be easily integrated into a pump. Optical techniques, such as those used in traditional IV pumps, are not required to detect air bubbles. Therefore, various problems encountered in optical methods can be avoided.

The presence of air within the IV system must be avoided. The pump of the present invention is constructed to prevent air bubbles from building up within the disposable pump chamber 10. Cylindrical first and second pump chambers 24, 26 and pressure sensing chamber 28
are arranged so that air bubbles always escape upwards. Therefore, no air bubbles can accumulate in these chambers. Similarly, first valves 44 and 46 are operated in a manner that does not create air bubbles within the disposable pump chamber.

In an embodiment of the invention, all of the pump mechanisms are arranged such that the inlet is lower than the outlet. As a result, air bubbles naturally flow out through the pump without accumulating anywhere within the disposable pump chamber 10. And it is especially important during the initial purge of the system, where all air bubbles must be removed from each chamber before the IV system is connected to the patient.

14 and 15, the diaphragm receptacle 22 is shown resiliently attached to the cam housing 23. In FIGS. In normal operation, the lower surface of the diaphragm housing and the upper surface of the cam housing are spaced approximately 1.2 m/m (0.05 inch) apart.

The diaphragm housing portion 22 has three screws 156.
It is positioned and attached to the cam housing 23 by the cam housing 23. This screw is the diaphragm housing part 2.
2 downwardly and is screwed into the cam housing 23. As shown in detail in FIG. 15, a spring 158 is loaded into recesses 160 and 162 in diaphragm housing 22 and cam housing 23, surrounding the axis of each screw 156. In normal pump operation, spring 158 is mounted in a compressed state and biased to separate cam housing 23 and diaphragm housing 22 .

The side cover 19 is opened and swung downward,
When the stop member 20 is disengaged from the pin 21 and pulled upwardly, the spring 158 causes the diaphragm receptacle 22 to move upwardly from the cam housing 23 until the top 156a of the screw 156 engages the bottom of the hole in the diaphragm receptacle 22. energize it so that it increases.

Cam housing 23 of diaphragm housing portion 22
A suitable arrangement for the diaphragm housing portion 22
alignment pin 48, as well as the positioning of disposable pump chamber 10 relative to both cam housing 23 and
Made by 50. As shown in FIG. 16, the pins 48 and 50
The shaft 166,1 provided in the cam housing 23 passes through the member 22 from the surface of the shaft 166,1.
It is penetrated into 67.

As described above, the diaphragm housing portion 22 is elastically supported with respect to the cam housing. Therefore, when inserting or removing the disposable pump chamber 10, all pistons and valves are
It is stored at a predetermined location on the upper surface of the diaphragm housing portion 22 .

Thus, the disposable pump chamber 10 remains in place, independent of the pistons and valves, no matter where the pump is stopped in its operating cycle. As shown in FIG. 15, the upper cover 18 has a diaphragm housing section 22.
It is attached to by a pin 21 and a stopper member 20.

The upper cover 18 and the diaphragm housing part 22 are
It is attached to the cam housing 23 via a side cover 19. The side cover 19 is attached to the cam housing 23 at one end by a hinge. The side cover 19 has a bent portion 19a and a handle portion 19b. The bends 19a are hooked onto the upper surface of the stop member 20 to hold the various parts of the pump in their respective desired operating states.

When the side cover 19 is separated from the top cover 18 and rotated downward, the top cover 18 and the diaphragm accommodating portion 22 do not immediately spring upward. Rather, these members only move slightly away from the cam housing 23 after the top cover 18 is slightly opened.

Figures 17, 18 and 19 illustrate the unique stop and hinge portion of the present invention. 17 is a bottom view of the pump housing 12, FIG. 18 is a plan view, and FIG. 19 is a front view. Figures 17 and 18
10 and 15, on the rear side of the cam housing 23, there are plate spring-like stop members and rear plate members 170, 172 that perform a cam action at the rear of the upper cover 18. is provided.

The back plate member 170 has a stop member 170a and a camming member 170b. Similarly, the metal back plate member 172 includes a stop member 172a and a cam action member 17.
It has 2b. The back plate member 70 is the cam housing 2
The rear plate member 172 is also attached to the rear side of the cam housing 23 with screws 176.

When the side cover 19 is closed and in operation, the stop members 170a and 172a are attached to the top cover 1.
8 engages the bottoms of recesses 178 and 180 at both ends of the rear. The stop members 170a and 172a are
Together with the side cover 19, the spring 158 holds the diaphragm accommodating portion 22 and the cam housing 23 apart from each other by a predetermined distance of about 1.2 m/m (0.05 inch).

As shown in FIG.
82 and are mutually pivotally supported. When the top cover 18 begins to open, the top cover 18 is supported by the hinge 182. The cam members 170b and 172b face the rear side surface of the upper cover 18 and act to push the upper ends of the back plate members 170 and 172 away from the rear side surface of the upper cover 18 and the diaphragm housing portion 22.

When top cover 18 is fully opened, the camming action by cam members 170b and 172b ultimately moves stop members 170a and 172a out of engagement with recessed portions 178 and 180 of top cover 18. . When the side cover 19 is placed in the open position, the movement of the stop members 170a and 172a disengaged from the recessed portions 178 and 180 is caused by the force of the spring 158 causing the diaphragm receiving portion 22 and the top cover 18 to move. Allows to be moved upwards.

Once the diaphragm accommodating portion 22 and the cam housing 23 are separated, the upper cover 18 is
It is further opened to allow removal and replacement of the disposable pump chamber 10. Inclined notch 1
84 and 186 further open the upper cover 18 without interference from the cam members 170b and 172b of the back plate members 170 and 172.

As shown in FIGS. 15, 18 and 19, side cover 19 is connected to cam housing 23 by front mounting blocks 188 and 190. The lower portions of hinges 192 and 194 are attached to the lower ends of front mounting blocks 188 and 190 by screws 196. The upper portions of hinges 192 and 194 are attached to the lower bottom of side cover 19 by bolts 198. Screws 200 connect front mounting blocks 188 and 190 to the front of the cam housing.

An embodiment of cams 98, 100, 102 and 104 is shown in FIG. These cams are shown from the perspective of motor 94. The first to fourth cams 98, 100, 102 and 104 rotate clockwise.

At the 0° reference point (eg, the start of a feed cycle), the first cam 98 is at its maximum radius, so the first valve 44 is closed. The second cam 100 is located at the beginning of the steady maximum diameter portion, so that the first piston 38 is stationary at the highest position. The third cam 102 is at its minimum radius, thereby closing the second valve 46. The fourth cam 04 increases in radius at a rate of 0.666 mils (1 mil = 1/1000 inch) for each degree of rotation, such that the second piston 40 increases by 0.666 mils for each degree of rotation of the cam. move upward step by step.

At this stage of operation, the amount of liquid delivered for each degree of rotation is 0.666 mil x [cross-sectional area of second pump chamber 26 (and second cylinder 34)] +
Equal to 0.666 mils x 1/2 x (the cross-sectional area between the pump chamber and each inner wall of the piston).

When rotated through 20 degrees, the first valve 44 remains closed, the first piston 38 is stationary, and the second valve 46 remains closed because the third cam 102 is at its maximum radius. The second piston 40 continues to move upwardly at a rate of 0.666 mils per degree of rotation.

At a rotation of 40 degrees, the first valve 44 is opened so that the first cam 98 is in the minimum radius position. At this point, the first piston 38 is still stationary and the fourth cam 104 is moving the second piston 40 at a rate of 0.666 mils per degree of rotation.

From 40° to 180° of rotation, the first valve 44 remains open and the radius of the second cam 100 decreases at a rate of 1.714 mils per 1° of rotation. As a result, the first pump chamber 24 has an angle of rotation of
Every 1°, the IV fluid is filled at a rate (V) calculated by the following formula:

V = 1.714 mil x (cross-sectional area of first pump chamber 24) + 1.714 x 1/2 x (cross-sectional area between each inner wall of the first pump chamber and first piston) At this time, the second valve 46 is also closed. , the second piston 40 rotates 0.666 degrees per 1 degree of rotation angle.
Rise at the rate of mill.

At a rotation of 180 degrees, the first valve 44 is still open and the second cam 100 covers a 40 degree section (180 degrees to 220 degrees) with a minimum radius area. Therefore, the first piston 38 is at the lowest position and remains stationary. The second valve 46 is still closed while the fourth cam 104 increases the radius at a rate of 0.666 mils for each degree of rotation.

At 200 degrees of rotation, the first cam 98 is at its maximum radius so that the first valve 44 is in its uppermost position, blocking the flow of liquid from the inlet tube 14.

The second cam 100 is in the steady minimum radius section and the first piston 38 remains in the lowest position.
A second valve 46 is located at the uppermost position and prevents the flow of liquid from the first pump chamber 24 to the second pump chamber 26. The radius of the fourth cam 104 continues to increase at a rate of 0.666 mils per degree of rotation, and the second piston 40 continues to move upward at that rate.

At a rotation of 220 degrees, the first valve 44 remains in its upper closed position and the first piston 38 remains in its lowermost position. The third cam 102 has then reached its minimum radius position so that the second valve 46 is in its lowest open position. The fourth cam 104
The maximum radius is reached at a position rotated to 220°.

From 220° to 360° of rotation, the first valve 44 is in the uppermost (closed) position. The second cam 100 increases in radius at a rate of 1.714 mils for every degree of rotation, and therefore the first piston 38 moves upward at that rate. The second valve 46 is in its lowest (open) position, thereby allowing liquid to flow from the first pump chamber 24 to the second pump chamber 26. The fourth cam 104 rotates every 1° of its rotation angle.
The radius increases at a rate of 1.048 mils and therefore the second piston 40 moves downward at that rate.

The amount of liquid discharged through the discharge tube 16 for each degree of rotation is equal to the difference in volume change between the first pump chamber 24 and the second pump chamber 26. In one embodiment, the first and second pump chambers 24 and 26 have the same cross-sectional area, and the difference in volume is such that the volume of the first pump chamber 24 decreases by 1.714 mils for every degree of rotation. ,
On the other hand, the second
The point is that the volume of the pump chamber 26 increases. Therefore, the volume of liquid delivered per 1° of its rotation angle is expressed as:

(1.714 mils - 1.048 mils) x (cross-sectional area of piston 38 or 40) + (1.714 mils - 1.048 mils) x 1/2 x (cross-sectional area between the corresponding pump chamber and each inner wall of the piston) is rewritten as follows.

0.666 mil x (cross-sectional area of second pump chamber 26) + 0.666 x 1/2 x cross-sectional area between each inner wall of the corresponding pump chamber and the piston) As a result, the amount pumped is less than the amount that the second piston 40 moves downward. It stays constant even when you're down. This is because the amount pumped from the first pump chamber 24 exceeds the amount received by the second pump chamber 26, and this excess amount is the same amount as the constant flow rate required.

Each cam 98, 100, 102 and 104
After rotating to 360° (or 0°), the next cycle begins. From the above it can be seen that a constant flow rate is provided by simply two valves and two cylinders. To perform the pumping action,
No reversing operation is required of motor 94.

In the particular embodiment described above, the cross-sectional areas of the first and second pump chambers 24, 26 are the same. This has various advantages during manufacturing. In particular, if the first piston 38 and the second piston 40 are the same size, they are interchangeable. However, it is also possible to use chambers with different cross-sectional areas. In order for the rate (flow rate) flowing out from the discharge tube 16 to be constant regardless of the direction of movement of the pistons, the first and second pistons 3
The particular ratio of actuation of 8, 40 is, of course, related to the cross-sectional area of the first and second pump chambers 24, 26.

In the pump of the present invention, the amount of liquid discharged is almost completely absorbed by the second and fourth cams 100, 10.
4 and the dimensions of the first and second pistons 38, 40. The amount of fluid is largely independent of the thickness of the first and second pump chambers 24,26. In many applications, the pump chamber 2
The effect of wall thickness at 4 and 26 is completely negligible.

The point at which the first and second valves 44 and 46 change their positions is immaterial, so long as one is set to close before the other opens, and that all valve position changes are independent of the second valve's position. It will also be appreciated that this is done while the cam 100 assumes a constant radial position.

Advantages An important advantage of the present invention is that all valve and piston movement is performed by a single camshaft 96. The valves are operated continuously by the configuration of the first and third cams 98, 102 without being biased by electrical sensing devices or springs.

The pump of the present invention is fail safe.
Has a function. As shown in FIG. 20, at least one valve is always closed throughout the feed stroke. This eliminates the risk of siphoning when the pump stops due to power source failure, inadvertent blockage, or other causes.

The pump of the present invention has the following important advantages over conventional IV pumps.

1 The IV pump of the present invention is small, accurate,
It is reliable and economical to manufacture and use.

2. The disposable pump chamber 10 is a very low cost component. As will be discussed in more detail below, disposable pump chamber 10 is made of plastic. The disposable pump chamber 10 does not have a valve or the like inside, so its cost is low.

3. The disposable pump chamber 10 uses cylindrical diaphragm pump chambers 24, 26 and end valves that simply sandwich the flow of liquid within the disposable pump chamber, thereby providing a seal between its moving parts. does not have. Since no seals are required between moving parts, the pump does not destroy blood cells and is used to process whole blood.

4. Disposable pump chambers provide an effective germ barrier. That is, the pump chamber 10 of the present invention is disposable and can be used only once.
Used only for IV therapy. Because of the low cost of disposable pump chamber 10, the cost of IV therapy is not limited by the cost of the device (mechanism).

5. The tolerances of the pump housing 12 and the disposable pump chamber 10 have little effect on the accuracy of the pump. As a result, a low cost disposable pump chamber can be manufactured.

6. The terminal valve function provided by the first and second valves 44, 46 does not require critical timing on the pump mechanism. The operation of these valves 44 and 46 occurs at relatively low speeds;
These valves 44 and 46 work in harmony with the operations of the first and second pistons 38 and 40 so that they have sufficient time to open and close.

7 The IV pump of the present invention can provide substantially constant flow using only two valves. Therefore, in the present invention, the cost of hardware (equipment) can be reduced and the efficiency of the pump can be increased.

8. One drive mechanism drives the first and second pistons 38 and 40 and the first and second valves 44 and 46. In addition to this, the drive mechanism does not require counter-rotation to obtain the desired operation of the two pistons and the two valves. This significantly reduces the complexity of the pump and increases its reliability of operation.

9. The pump does not require stretching of an elastic body, as is the case with peristaltic and pulsating pumps. The possibility of air incorporation into the injection volume as a result of stretching of the elastic body is therefore ignored.

10 The IV pump of the present invention does not contain elastic bodies, spring bias (excluding those for overcoming friction),
There is no pumping action against the friction seal. Therefore, the energy required for pumping can be used effectively.

11 The pump of the present invention reduces power or battery consumption,
If the pump stops due to inadvertent closure or other reasons, it may automatically bias off. This is because no matter where the pump is in the pump cycle, one of the two valves 44, 46 is always closed.

One valve is adapted to open only after the other valve has closed. This allows failsafe and prevents siphoning when the pump is stopped.

12 The pump is of low cost and simple construction and has a detection and alarm device in case of an increase in back pressure of a preset value. Pressure sensing chamber 28
and the third piston 42 trigger the alarm.
for selecting one or more backpressure limit values;
To provide a simple and efficient method.

Therefore, the limit value of the back pressure in the pump of the invention is chosen to be smaller than the maximum back pressure that the pump can supply. This improves safety for patients on dialysis and other disorders.

13 The present invention provides a simple and effective anti-bubble system. The change in dielectric constant between air and fluid is a low-cost,
It is a simple and effective method. The warning is
This alerts the doctor to the presence of air in the pump.

Although the invention has been shown in conjunction with preferred embodiments, it will be recognized that changes may be made in portions or forms without departing from the spirit of the invention or the scope of the claims. for example,
Although IV therapy applications are the most important application of the present invention, other pump requirements may also be met by the pump of the present invention.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the IV pump and disposable pump chamber of the present invention. Figure 2 shows
FIG. 2 is a perspective view of the IV pump and disposable pump chamber with the pump housing open and the disposable pump chamber moved. Figures 3A, 3B and 3C are top, side and bottom views of the disposable pump chamber. Figure 4 is 4 in Figure 3A.
FIG. 4 is a sectional view of the pump chamber taken along line -4. FIG. 5 is a cross-sectional view of the pump chamber taken along line 5--5 of FIG. 3A. Figure 6 is 6-6 in Figure 3A.
FIG. 3 is a cross-sectional view of the pump chamber along lines; FIG. 7 is a cross-sectional view of the IV pump taken along line 7-7 in FIG. 8 and 9 are detailed views of the encoder device of the IV pump. Figure 10 shows
8 is a cross-sectional view of the IV pump taken along line 10-10 in FIG. 7. FIG. FIG. 11 is a plan view of the cam housing of the IV pump. FIG. 12 is a detailed view showing the backpressure contact. Figure 13 is 13 in Figure 7.
It is a sectional view taken along the line -13. Figure 14 shows IV
It is a top view of the diaphragm accommodating part of a pump. 15 is a sectional view taken along line 15-15 in FIG. 14. FIG. 16 is a sectional view taken along line 16-16 in FIG. 14. FIG. 17 is a bottom view of the IV pump. FIG. 18 is a plan view of the IV pump. FIG. 19 is a partially cutaway front view of the IV pump. Fig. 20 shows the four-wheel drive system used to drive the first and second pistons and the first and second valves of the pump.
Showing two cams. 10...disposable pump chamber, 12...pump housing, 14...introduction tube, 16...
...Discharge tube, 22...Diaphragm housing section,
23...cam housing, 24, 26...first,
2nd, pump chamber, 28... pressure detection chamber, 32, 34, 36... 1st to 3rd cylinders,
38, 40, 42...first to third piston, 4
4, 46...first and second valves, 94...motor, 98,100,102,104...first to fourth cams.

Claims (1)

[Scope of Claims] 1. A pump used in combination with a disposable pump chamber having, from an inlet to an outlet, a first flexible passage section, a first pump chamber, a second flexible passage section, and a second pump chamber. The pump includes: a pump housing housing a disposable pump chamber; a first cylinder disposed within the pump housing housing a first pump chamber; and a first cylinder housing a second pump chamber. , a second cylinder disposed within the pump housing, a first piston that reciprocates within the first cylinder, a second piston that reciprocates within the second cylinder, and the first piston that reciprocates within the second cylinder. a first valve controllably compressing a flexible passageway portion and controlling fluid flow between the introduction portion and the first pump chamber; , a second valve controlling fluid flow between the first and second pump chambers; and a first piston relative to the first cylinder and a second piston relative to the second cylinder. pump chamber drive means for causing a change in the volume of said first and second pump chambers; A non-operating IV pump comprising: valve control means for controlling a valve. 2. The driving means includes a motor and a camshaft driven by the motor and having a cam for driving the first and second pistons, and the valve control means is attached to the camshaft and includes a camshaft that is driven by the motor and has a cam for driving the first and second pistons. A non-swivel IV pump according to claim 1, including a cam for driving the first and second valves. 3. The driving means is such that when the volume of the first pump chamber increases, the volume of the second pump chamber decreases;
Also, the first pump chamber is configured such that when the volume of the first pump chamber decreases, the volume of the second pump chamber increases.
the piston and the second piston are actuated, and the valve control means is configured to allow fluid to flow into the first pump chamber through the first flexible passageway portion when the volume of the first pump chamber increases. actuating the first valve to move the second flexible passageway portion from the first pump chamber to the second pump chamber when the volume of the first pump chamber decreases and the volume of the second pump chamber increases; The non-operating valve according to claim 1 or 2, which enables inflow of fluid through the valve and drives the second valve.
IV pump. 4. A pump used in combination with a disposable pump chamber having, from the inlet to the outlet, a first flexible passageway section, a first pump chamber, a second flexible passageway section, a second pump chamber, and a pressure sensing chamber; the pump includes: a pump housing housing a disposable pump chamber; a first cylinder disposed within the pump housing housing a first pump chamber; a second cylinder disposed within the pump housing; a first piston that reciprocates within the first cylinder; a second piston that reciprocates within the second cylinder; and the first flexible cylinder. a first valve controllably compressing the flexible passageway portion and controlling fluid flow between the introduction portion and the first pump chamber; a second valve controlling fluid flow between the first and second pump chambers; and causing relative movement of the first piston with respect to the first cylinder and relative movement of the second piston with respect to the second cylinder. pump chamber drive means for changing the volumes of the first and second pump chambers; and the first and second valves such that one of the first and second flexible passage portions is always compressed. and pressure sensing means for sensing the pressure within the pressure sensing chamber.
IV pump. 5. The driving means includes a motor and a camshaft driven by the motor and having a cam for driving the first and second pistons, and the valve control means is attached to the camshaft and includes a camshaft that is driven by the motor and has a cam for driving the first and second pistons. 5. A non-operating IV pump according to claim 4, including a cam for driving the first and second valve means. 6. The driving means is such that when the volume of the first pump chamber increases, the volume of the second pump chamber decreases;
Also, the first pump chamber is configured such that when the volume of the first pump chamber decreases, the volume of the second pump chamber increases.
the piston and the second piston are actuated, and the valve control means is configured to allow fluid to flow into the first pump chamber through the first flexible passageway portion when the volume of the first pump chamber increases. actuating the first valve to move the second flexible passageway portion from the first pump chamber to the second pump chamber when the volume of the first pump chamber decreases and the volume of the second pump chamber increases; 6. A non-operating valve as claimed in claim 4 or claim 5 for actuating the second valve to allow inflow of fluid through the valve.
IV pump.