JP5256551B2 - Cardiac function simulator - Google Patents

Description

  The present invention relates to a cardiac function simulator that can be used for an endurance test of an auxiliary circulation device.

  At present, an auxiliary circulation device (an auxiliary artificial heart) is widely used for patients with advanced heart failure. This auxiliary circulation device is required to have high reliability, and must be sufficiently tested before being put into practical use.

  Therefore, several devices that simulate the cardiac function and the circulatory system have been proposed in order to test such an auxiliary circulatory device, and some of these devices use a pulsating pump to simulate the heart. doing. When a pulsation pump is used, since the contraction / expansion cycle of the pump chamber can be adjusted, various pulsations of the heart can be simulated. However, these pulsation pumps usually cannot adjust the pulsation state such as contractile force. In this case, various hearts with different contractile forces cannot be sufficiently simulated.

  As a technique for solving this problem, a circulation simulator using a passive filling mechanism has been proposed (Non-Patent Document 1). This is a flexible sac that simulates the contraction / expansion of the left ventricle inside the housing, and the contraction force of the flexible sac is adjusted by pressing the flexible sack with a piston driven by a linear motor. To do. However, in this case, a mechanical force is directly applied to the flexible sack, and the flexible sack is likely to deteriorate. Therefore, the point that durability of a system is impaired becomes a problem.

Yokoyama Takamasa et al., "Development of left heart systolic evaluation index Emax changeable passive filling mechanism left heart simulated heart model", 2009, 48th Annual Meeting of the Japanese Society for Medical and Biological Engineering

  SUMMARY OF THE INVENTION An object of the present invention is to provide a cardiac function simulator capable of setting a pulsation state such as the contraction force of the heart and the number of pulsations, and achieving high durability.

  A cardiac function simulator according to an aspect of the present invention includes a tank that stores a fluid in which an inlet and an outlet of a fluid are formed, a unidirectional first valve that circulates the fluid from the tank, and a reciprocating motion. A pump chamber for sucking and pumping fluid by reciprocation of a member, an inlet for introducing fluid from the first valve into the pump chamber, a pumping outlet for pumping fluid from the pump chamber, and the pump chamber A pump comprising a pump head formed with a communicating opening, and a closed first type which is connected to the opening formed in the pump head of the pump and adjusts the compliance (extensibility) of the pump chamber by the amount of air inside. It is characterized by comprising a chamber, a unidirectional second valve that allows fluid from the tank to flow, and a conduit that allows fluid from the second valve to flow to the inlet of the tank.

  According to the present invention, it is possible to provide a cardiac function simulator capable of setting the pulsation state such as the contraction force of the heart and the number of pulsations and achieving high durability.

It is a block diagram of a cardiac function simulator according to an embodiment of the present invention. It is a figure explaining the correspondence of a concentric function simulator and a systemic circulation system. It is the schematic of the internal structure of the pulsation pump and closed type chamber of a concentric function simulator. It is AA 'sectional drawing shown to FIG. 3A. It is a figure explaining the relationship between operation | movement of the pulsation pump of a concentric function simulator, a systemic circulatory system, and a pulmonary circulatory system. It is a figure explaining the relationship between operation | movement of the 1st closed type chamber of a concentric function simulator, a systemic circulatory system, and a pulmonary circulatory system. It is a graph which shows the simulation result of a concentric function simulator.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[Overall system]
FIG. 1 is a block diagram of a cardiac function simulator according to an embodiment of the present invention.

  The heart function simulator includes a circulatory circuit that simulates the systemic circulatory system (or pulmonary circulatory system).

  The circulation circuit includes a reservoir 1 that simulates the left or right atrium, a pulsation pump 5 that simulates the left or right ventricle, and a closed chamber 14 that simulates the aorta or pulmonary artery, and the pulsation pump 5 and the closed chamber. 14 and the bypass flow for the auxiliary artificial heart consisting of the pipelines 35 and 36 are formed in parallel with the main flow, and the tube from the closed chamber 14 to the reservoir 1 is formed. A total flow is formed by the paths 17 and 19.

  A reservoir 1 for storing fluid and a pulsation pump 5 include a conduit 3 for transferring fluid from the reservoir 1 to the pulsation pump 5, and conduits 11, 17, and 19 for transferring fluid from the pulsation pump 5 to the reservoir 1. Connected by. Further, the one-way valve 4 (first valve) and the one-way valve 10 (second valve) for flowing fluid in one direction are provided on the suction port side and the pulse outlet side of the pulsation pump 5, respectively. Furthermore, a closed chamber 6 (first chamber) that adjusts the internal pressure of the pump chamber of the pulsating pump 5, a closed chamber 14 (second chamber) that provides compliance (extensibility) between the pipe lines 11 and 17, And an electric proportional control valve 18 for adjusting the fluid resistance of the pipe line 17.

  Here, the pump head of the pulsation pump 5 and the pipe line 11 are provided with a first branch port 5b and a second branch port 11a, respectively. An evaluation pump 20 to be evaluated is connected to these branch ports 5b and 11a via pipes 35 and 36, respectively.

  Further, the heart function simulator includes an outlet 1 b side of the reservoir 1, a pulsation pump 5, a closed chamber 6, a closed chamber 14, a vicinity of the inlet 14 b of the closed chamber 14 of the pipe 11, and the pipe 17. Pressure sensors 21, 22, 31, 33, 23, 24, near the outlet 14c of the closed chamber 14, near the inlet of the evaluation pump 20 in the conduit 35, and near the outlet of the evaluation pump 20 in the conduit 36, respectively. 25 and 26 are provided. These pressure sensors 21 to 26, 31, and 33 can measure the pressure of each part in real time. The pipes 11, 17, and 36 are provided with flow meters 12, 34, and 37 that detect the flow rate of the fluid, respectively. The outputs of the pressure sensors 21 to 26, 31, and 33 and the flow meters 12, 34, and 37 are used for counting simulation results by the measuring device, and are fed back to the control device and used for controlling the circulation circuit. .

[Correspondence between cardiac function simulator and systemic circulation]
Next, correspondence between the cardiac function simulator and the systemic circulation system according to the present embodiment will be described.

  From here onwards, for convenience of explanation, the systemic circulation system will be described as an example. However, the left ventricle is the right ventricle, the left atrium is the right atrium, the aorta is the pulmonary artery, the peripheral vascular resistance is the pulmonary vascular resistance, and the mitral valve The same applies to the pulmonary circulatory system if the tricuspid valve is a pulmonary valve and the vena cava is a pulmonary vein.

  FIG. 2 is a diagram for explaining the heart function simulator and the systemic circulation system, and arrows A1 to A4 in the figure represent the flow of blood.

  Blood flowing from the left atrium to the left ventricle via the mitral valve in the living body (arrow A4) corresponds to the flow of fluid drawn from the reservoir 1 to the pulsation pump 5 via the one-way valve 4 in the cardiac function simulator. . Blood flowing from the left ventricle to the aorta via the aortic valve (arrow A1) is pumped from the pulsating pump 5 to the closed chamber 14 via the conduit 11 via the one-way valve 10 in the cardiac function simulator. It corresponds to. The blood (arrow A2) heading from the aorta to the peripheral vascular resistance corresponds to the fluid flowing from the closed chamber 14 to the electric proportional control valve 18 via the conduit 17. The blood (arrow A3) heading from the peripheral vascular resistance to the left atrium via the vena cava corresponds to the fluid flowing into the reservoir 1 from the electric proportional control valve 18 via the conduit 19.

[Description of each function block]
Next, each functional block of the cardiac function simulator according to the present embodiment will be described.

  The reservoir 1 includes a reservoir body 1c that stores fluid. On the side surface of the reservoir main body 1c, there are an inlet 1a for taking the fluid flowing in from the pipe 19 into the reservoir main body 1c, and an outlet 1b for letting the fluid stored in the reservoir main body 1c flow out to the pipe 3. Is formed. The reservoir 1 is provided on the downstream side of the electric proportional control valve 18 and can simulate the left atrial pressure of the living body. Further, the left atrial pressure can be adjusted by changing the level of the fluid in the reservoir 1. The left atrial pressure can be detected by a pressure sensor 21 provided on the outlet 1b side of the reservoir 1.

  Furthermore, a heater 2 as a heat source can be installed in the reservoir 1 as necessary. In this case, the temperature of the fluid circulating in the cardiac function simulator can be kept constant.

  The pulsation pump 5 includes a pump chamber that sucks and pumps fluid by a reciprocating motion of a reciprocating member, an intake port that introduces fluid into the pump chamber, and a pulsation outlet that pumps fluid from the pump chamber. An opening 5 a for connecting the closed chamber 6 is formed in the pump head of the pulsating pump 5.

  The pulsating pump 5 has a structure as shown in FIGS. 3A and 3B. Here, FIG. 3A is a schematic view of the internal structure of the pulsation pump 5 and the closed chamber 6, and FIG. 3B is a cross-sectional view taken along line AA ′ shown in FIG. 3A.

  A flexible diaphragm 104 is attached to the tip of the drive shaft 101 that is driven to reciprocate by electromagnetic force of a pump body (not shown). The diaphragm 104 forms a pump chamber 120 between itself and the pump head 110, and a peripheral portion thereof is held by the pump head 110 and the bracket 111. In the pump head 110, an intake fluid passage 121 extending from the pump chamber 120 in the left direction in FIG. 3A and a pumping fluid passage 122 extending from the pump chamber 120 in the right direction in FIG. 3A are formed.

  In the pump head 110, an opening 5a is formed at the center of the front surface. The opening 5 a is connected to an inlet 6 b at the lower part of the closed chamber 6 through a pipe 123 extending forward from the pump head 110.

  A housing 113 that constitutes a suction port is provided at the end of the suction fluid passage 121. A one-way valve 4 is connected in the housing 113. On the other hand, the housing 105 constituting the outlet is connected to the end of the outlet fluid passage 122. A one-way valve 10 is connected in the housing 105.

  Regarding the one-way valves 4 and 10, duckbill valves, ball valves, umbrella valves, two-leaf valves, one-leaf valves, biological valves, etc. can be easily replaced. Characteristics (fluid resistance, reverse flow rate, impact) can be compared.

  Moreover, hemodynamics in diseases caused by valve malfunction (valve stenosis, insufficiency, regurgitation) can be easily reproduced by changing the valve material, mechanism, and structure.

  Further, when a transparent acrylic material is used for the housings 113 and 105 and the pulsation pump 5, the behavior of the one-way valves 4 and 10 and the diaphragm 104 of the pulsation pump 5 can be visually evaluated.

  The pulsating pump 5 having the above structure can control the number of pulsations of the diaphragm by changing the reciprocating cycle of the drive shaft. As a result, the amount of fluid pumped from the pump chamber 120 can be changed.

  Further, the pulsation pump 5 can electronically control the stroke length (the operating range of the diaphragm). The stroke volume increases as the stroke length increases, and the stroke volume decreases as the stroke length decreases.

  The closed chamber 6 connected to the opening 5a of the pulsation pump 5 gives arbitrary compliance to the pulsation pump 5 by changing the amount of air in the housing. An air flow path 7 and air pressure adjusting valves 8 and 30 are installed in the air port 6a at the upper part of the closed chamber 6, and the amount of air can be controlled electronically. Note that increasing the amount of air in the closed chamber 6 increases the compliance and decreases the contraction force of the pulsating pump 5. When the amount of air decreases, the compliance decreases and the contractile force of the pulsating pump 5 increases. The closed type chamber 6 regulates the air from the air flow path 7 using the air pressure adjusting valves 8 and 30, and continuously applies pressure to the air in the closed type chamber 6 to keep the liquid level in the closed type chamber 6 constant. Can keep.

  The pulsating pump 5 can be provided with a safety valve 9 through an opening 5c formed in the pump head 110 from the viewpoint of safety. In this case, even if excessive pressure is applied to the pulsation pump 5, the fluid can be released to the safety valve 9.

  Next, the relationship between the systole and diastole of the pulsating pump 5 and the systemic circulation system will be described with reference to FIG.

  (1) in FIG. 4 is a diagram for explaining the relationship between the systole of the pump chamber of the pulsating pump 5 and the systemic circulation system. When the pump chamber of the pulsating pump 5 contracts, fluid in the pump chamber is pumped out toward the closed chamber 14 and the electric proportional control valve 18 through the one-way valve 10. This corresponds to the operation of the systemic circulation system during the systole of the living heart as indicated by (1) in FIG. That is, the contraction of the pump chamber of the pulsating pump 5 corresponds to the contraction operation of the left ventricle indicated by the arrow B in (1) in FIG. As a result, the blood in the left ventricle becomes peripheral blood vessel resistance corresponding to the electric proportional control valve 18 via the aortic valve corresponding to the one-way valve 10 and the closed chamber 14 corresponding to the aorta as shown by arrows A1 and A2. Be beaten by.

  (2) in FIG. 4 is a diagram for explaining the relationship between the expansion period of the pump chamber of the pulsating pump 5 and the systemic circulation system. When the pump chamber of the pulsation pump 5 is expanded, the fluid stored in the reservoir 1 is sucked into the pump chamber of the pulsation pump 5 through the conduit 3 and the one-way valve 4. This corresponds to the operation of the systemic circulation system in the diastole of the living heart, as shown in (2) in FIG. That is, the expansion of the pump chamber of the pulsating pump 5 corresponds to the expansion operation of the left ventricle indicated by the arrow C in FIG. As a result, the blood that has returned to the left atrium corresponding to the reservoir 1 by the vena cava corresponding to the duct 19 as shown by the arrow A3 has the mitral valve corresponding to the one-way valve 4 as shown by the arrow A4. Via the pulsation pump 5.

  Next, the relationship between the operation of the closed chamber 6 and the body circulation system will be described.

  FIG. 5 is a view for explaining the relationship between the closed chamber 6 and the body circulation system. In FIG. 5, (1) indicates that the closed chamber 6 does not contain air, and (2) indicates the closed chamber 6. It is a figure when air is contained.

  As shown in FIG. 5 (1), when air is not contained in the closed chamber 6, the contraction force B of the pump chamber of the pulsating pump 5 is not reduced as indicated by the dotted line D in the figure. Thereby, the pulsation pump 5 can pump a lot of fluid toward the pipe line 11 (dotted line arrows A1 and A2 in the figure). On the other hand, as shown in (2) in FIG. 5, when air is contained in the closed chamber 6, the contraction force B of the pump chamber of the pulsating pump 5 is reduced to B ′ as indicated by the dotted line D ′ in the figure. Resulting in. In this case, the pulsation pump 5 cannot sufficiently contract the pump chamber, and the stroke volume is reduced (dotted arrows A1 ′ and A2 ′ in the figure).

  Thus, the amount of stroke of the pulsating pump 5 changes by changing the air pressure in the closed chamber 6. This corresponds to a change in the left ventricular stroke volume in the systemic circulation. As a result, in the case of the true heart function simulator, not only the normal heart function with sufficient left ventricular stroke volume but also the heart function of the failing heart with weak contraction force of the left ventricle can be simulated. be able to.

  Further, in a conventional cardiac function simulator, a flexible diaphragm or sack such as a polyurethane thin film is used to reproduce the flexibility of a living heart. However, in this case, it has been difficult to quantitatively control the compliance component of the heart. The pulsation pump 5 of the heart function simulator can quantitatively change the compliance component of the pulsation pump 5 by adjusting the amount of air in the closed chamber 6 attached to the metering pump. Thereby, it is possible to reproduce the decrease in the contractile ability in the failing heart.

  Furthermore, it is possible to change the stroke volume by continuously adjusting the pump stroke of the pulsating pump 5 with the control device, and quantitatively reproduce the decrease in the cardiac output in the failing heart. be able to. Similarly, since the number of pulsations of the pulsation pump 5 can be continuously changed by the control device, the volume of the living heart and the rise of the internal pressure of the pump can be changed together with the air amount of the closed chamber 6 and the pump stroke. it can. The adjustment range can be reproduced from the heart failure state to the healthy heart and beyond, so the long-term endurance test in the heart failure state according to the purpose of use of the test device including the evaluation pump and the more severe in the accelerated test The user can arbitrarily set the test conditions such as a test under various conditions.

  The closed chamber 14 is provided on the downstream side of the flow meter 12 and applies a blood vessel compliance component to the pressure waveform pumped out from the pulsation pump 5. An air flow path 15 and an air pressure adjusting valve 16 and 32 are installed in the air port 14a at the upper part of the housing of the closed chamber 14, and the amount of air can be controlled electronically. By adjusting the amount of air inside the closed chamber 14, the pulse pressure of the arterial waveform (pressure of the fluid flowing in the duct 11) can be changed to an arbitrary value. Note that increasing the amount of air in the closed chamber 14 increases vascular compliance and decreases the pulse pressure of the pressure waveform.

  Similarly to the closed chamber 6, the closed chamber 14 also adjusts the air from the air flow path 15 using the air pressure adjusting valves 16 and 32 to continuously apply pressure to the air in the closed chamber 14, thereby closing the closed chamber 14. The liquid level in the chamber 14 can be kept constant. In this way, by keeping the air pressure and capacity of the closed chamber 14 constant, it is possible to prevent changes in compliance due to air leakage during long-term operation in the durability test.

  Furthermore, time-varying characteristics can be imparted to compliance through continuous control.

  In the conventional cardiac function simulator, a flexible tube or the like is used for the conduit to reproduce the compliance component of the aorta. On the other hand, in the heart function simulator, most of the pipelines can be made of metal piping, and in this case, most of the compliance components of the aorta are determined by the amount of air in the closed chamber 14. That is, it becomes possible to quantitatively control the compliance component, which was difficult with a conventional cardiac function simulator.

  The electric proportional control valve 18 is provided on the downstream side of the closed chamber 14. The resistance of the circuit can be adjusted by adjusting the opening degree of the electric proportional control valve 18. Thereby, the fluid can be adjusted to an arbitrary pressure and flow rate. Further, the back load can be kept constant in the durability test by feeding back the output of the pressure sensor to the control device.

  Ferrule piping can be used for the pipe lines 11, 17, and 19. In this case, physiological saline or glycerin aqueous solution can be used for the fluid depending on the corrosion resistance of the ferrule pipe. This enables a test using a fluid adjusted to a viscosity equivalent to that of blood. The flow rate of the fluid in the pipes 11 and 17 is measured by the flow meters 12 and 34, respectively.

  The evaluation pump 20 is connected so as to bypass the branch port 5 b of the pulsation pump 5 and the branch port 11 a upstream of the closed chamber 14 via pipe lines 35 and 36. At this time, the generated pressures of the pulsating pump 5 and the closed chamber 14 respectively become a preload and a postload on the evaluation pump 20.

  As described above, the auxiliary circulation device as a sample is connected to the pulsation pump 5 corresponding to the left ventricle on the blood removal (inhalation) side and to the vicinity of the closed chamber 14 corresponding to the aorta on the blood supply (pumping) side. By doing so, it is possible to test under the same load condition (test device front-rear pressure, flow rate) as when it is mounted on a living body.

  In addition, since the number of pulsations and stroke length of the pulsation pump 5, the electric proportional control valve 18, and the amount of air in the closed chambers 6 and 14 can be adjusted by the control device, physiological conditions (the number of pulsations) can be adjusted to various test conditions. , Heart rate, flow rate) and lifestyle patterns (day / night, rest / exercise, etc.).

  Various pumps can be applied as the evaluation pump 20.

[simulation result]
FIG. 6 shows a simulation result by the true heart function simulator. In FIG. 6, (1) is the flow rate of the fluid in the pipe line 11 and corresponds to the aortic flow rate. In FIG. 6, (2) is the internal pressure of the pump chamber of the pulsating pump 5 and corresponds to the left ventricular pressure. (3) in FIG. 6 is the fluid pressure before and after the closed chamber 14 and corresponds to the aortic pressure. In this simulation, duckbill valves are used for the one-way valves 4 and 10.

  In the period I to II in the figure, the pump chamber expands and in the period II to III the pump chamber contracts. The period of the pump that combines these expansion and contraction periods is about 0.85 s, which corresponds to a heart rate of 70 bpm. Moreover, the solid line in the figure indicates a healthy heart, and the broken line indicates a failure heart simulation result.

  First, expansion of the pump chamber of the pulsating pump 5 (left ventricle) starts at time I, the one-way valve 4 (mitral valve) is opened at time b, and fluid (blood) is discharged from the reservoir 1 (left atrium). Inhaled by the pulsation pump 5. Further, since the one-way valve 10 (aortic valve) is closed from time a to time d, almost no fluid (blood) flows through the conduit 11 (aorta).

  Subsequently, at time II, the contraction of the pump chamber of the pulsating pump 5 starts, and at time d, the internal pressure (left ventricular pressure) of the pulsating pump 5 substantially matches the fluid pressure (aortic pressure) in the conduit 11. Thereafter, when the internal pressure of the pulsating pump 5 exceeds the fluid pressure in the pipe 11, the one-way valve 10 is opened, and the flow rate in the pipe 11 increases.

  Subsequently, at time III, expansion of the pump chamber of the pulsation pump 5 starts, and the rate of increase in the flow rate gradually decreases. Thereafter, when the internal pressure of the pulsating pump 5 becomes equal to or lower than the fluid pressure in the pipe line 11, the one-way valve 10 is closed at time e and no new fluid is pumped out of the pipe line 11.

  Subsequently, at time f, when the internal pressure of the pulsating pump 5 decreases and becomes equal to or lower than the internal pressure of the reservoir 1 (not shown), the one-way valve 4 is opened and fluid is sucked into the pump chamber. Thereafter, the fluid in the conduit 19 (vena cava) returns to the reservoir 1. Thereafter, the above cycle is repeated after time f.

  As described above, a phase relationship similar to a biological waveform can be obtained by using the true heart function simulator. Moreover, the characteristics of the pressure waveform can be sufficiently reproduced. In particular, as can be seen from (3) in FIG. 6, by using a duckbill valve for the one-way valves 4 and 10, the disc caused by the closure of the aortic valve during the transition from the systole to the diastole of the living heart Rotic notch is also reproduced. In addition, the steep rise and the gradual fall that are characteristic of the flow rate waveform are also reproduced.

  In the heart function simulator, the flow rate of the circulation circuit can be controlled by changing the parameters of the electric proportional control valve 18, the pulsation pump 5, the closed chamber 6, and the closed chamber 14. In particular, the contraction force of the pulsating pump 5 can be varied by adjusting the water level of the closed chamber 6 connected to the pulsating pump 5. Therefore, for example, when the water level of the closed chamber 6 is lowered, the flow rate and pressure are also lowered accordingly, so that the failure heart shown by the broken line in FIG. 6 can be simulated. Further, in the case of an experimental system targeting the evaluation pump 20, the ratio between the flow rate of the entire system including the fluid flowing through the evaluation pump 20 and the bypass flow flowing through the evaluation pump 20 can be arbitrarily changed. As a result, for example, if there is no blood flow from the left ventricle to the aorta due to a large auxiliary flow rate, the aortic valve will not open and close, resulting in problems such as a thrombus. Can be reproduced.

  In addition, since parameters such as cardiac function, peripheral vascular resistance, and vascular compliance can be set quantitatively, a simulator for medical education such as quantitative evaluation of changes in pressure waveform and flow rate waveform when these parameters are changed can be used. Can be applied. For example, a disease state such as arteriosclerosis in which a decrease in compliance is recognized can be reproduced by reducing the amount of air in the closed chamber 14.

  Furthermore, according to the core function simulator, the day mode (the state of the human body's day beats, blood pressure, etc.), the night mode (also the bedtime state), the exercise mode (also the state of active exercise), the beat It is also possible to simulate according to a human life pattern such as repeating the motion stop mode in a predetermined cycle (for example, one day).

[Summary]
As described above, according to the present embodiment, the left ventricular pressure, aortic pressure, and aortic flow similar to those of a living body can be generated in a phase relationship that matches the living body. From these characteristics, this apparatus can be used as a simulator for cardiac function / circulatory system of a living body.

  DESCRIPTION OF SYMBOLS 1 ... Reservoir, 1a ... Inlet, 1b ... Outlet, 2 ... Heater, 3 ... Pipe line, 4 ... One-way valve, 5 ... Pulsating pump, 5a 5c ... Open, 5b ... Branch port, 6 ... Closed chamber, 6a ... Air port, 6b ... Inlet, 7 ... Air flow path, 8, 30 ... Air pressure regulating valve, 9 ... Safety valve, 10 ... One-way valve, 11 ... Pipe line, 11a ... Branch port, 12 ... Flow meter, 14 ... Closed chamber, 14a ... -Air port, 14b ... Inlet, 14c ... Outlet, 15 ... Air flow path, 16, 32 ... Air regulating valve, 17 ... Pipe line, 18 ... Electric proportional control Valve, 19 ... Pipe line, 20 ... Evaluation pump, 21-26, 31, 33 ... Pressure sensor, 34, 37 ... Flow meter, 35, 36 ... The conduit.

Claims (7)

A tank for storing the fluid in which the fluid inlet and outlet are formed;
A unidirectional first valve for circulating fluid from the tank;
A pump chamber for sucking and pumping fluid by reciprocating movement of a reciprocating member, an inlet for introducing fluid from the first valve into the pump chamber, an outlet for pumping fluid from the pump chamber, the pump A pump comprising a pump head formed with an opening leading to the chamber;
A closed first chamber connected to an opening formed in the pump head of the pump and adjusting the compliance of the pump chamber according to the amount of air inside;
A unidirectional second valve for circulating fluid from the tank;
A cardiac function simulator comprising: a conduit for allowing fluid from the second valve to flow to the inlet of the tank. The pump head of the pump is formed with a first branch port for flowing the fluid in the pump chamber to an external evaluation pump,
The cardiac function simulator according to claim 1, wherein a second branch port through which fluid pumped out from the evaluation pump flows is formed in the conduit. The cardiac function simulator according to claim 1 or 2, further comprising a closed second chamber that is inserted into the pipe and adjusts the compliance of the pipe according to the amount of air inside the housing. The cardiac function simulator according to any one of claims 1 to 3, further comprising an electric proportional control valve that is inserted into the pipe and adjusts a diameter of the pipe. The cardiac function simulator according to any one of claims 1 to 4, further comprising a heater for heating the fluid in the tank. The cardiac function simulator according to any one of claims 1 to 5, wherein the first and second valves are duckbill valves. The pump head of the said pump is formed with the safety valve which flows out the fluid in the said pump chamber outside when the internal pressure in the said pump chamber becomes more than predetermined pressure. The cardiac function simulator according to any one of claims.

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