JPH0422105B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pulsatile flow generator for testing artificial organs used for testing or researching the durability of artificial organs of the circulatory system used in the human body. Regarding.

[Conventional technology]

A fluid flow that periodically generates predetermined pressure fluctuations within a certain pressure range is called a pulsatile flow. For example, the flow in the circulatory system in which blood in the human body flows from the heart to various parts of the human body and returns to the heart is a pulsatile flow. Pulsatile flow allows better maintenance of organ circulation and peripheral circulation than non-pulsatile flow, and is therefore said to be advantageous in terms of cardiac function.

BACKGROUND ART Conventionally, in the field of medical device technology, several pulsatile flow generating devices have been proposed to replace the function of the heart for a short period of time due to the need to send blood to various parts of the human body during heart surgery.

A pulsatile flow generator using a roller pump is one such device. FIG. 5 is a schematic diagram of a roller pump, and the principle is as shown in this diagram, the roller R and pump chamber W are brought into contact with each other halfway through their rotation, and the pump chamber W is squeezed while rotating the roller 6. be. For example, medical science [VoL.56, No. 5 (1986)] connects such a roller pump to a voltage control device and an arithmetic circuit, and the pulsating flow generating device connects such a roller pump to a voltage control device and an arithmetic circuit, and operates within a certain angular range once or twice during one revolution of the roller R. This device generates pulsating flow by rapidly increasing the rotational speed.
According to the above-mentioned research group paper, it has been confirmed that this device can relatively easily generate good pulsatile flow.

[Problem that the invention seeks to solve]

Although the pulsatile flow generating device using the roller pump described above is capable of generating pulsatile flow, it is not possible to generate pulsatile flow due to actual physiological phenomena of the human body, such as blood vessels in myocardial restriction, hypertension, pulsatile flow fluctuations between high and low pressure, etc. cannot be reproduced without complex control.

Artificial organs are currently in the development stage, and the pulsatile flow generator described above is only used for a short time when the human body needs it, such as during surgery. Therefore, the durability of the artificial organ itself was not so much of an issue, but the short-term performance of static strength such as pressure resistance was the issue. However, once the performance of artificial organs has been perfected, the next issue becomes durability over long-term use.

For such durability, the materials used, strength design, etc. are important factors, but fatigue strength is the most important issue. Although various strength and fatigue tests for the materials themselves have been devised and used, no method has yet been developed for performing strength or fatigue tests on artificial organs that take into account the stress generated by internal pressure. Therefore, durability testing of artificial organs under conditions equivalent to or similar to physiological phenomena in the human body, especially conditions including pulsatile flow, will become an issue in the future.

[Purpose of the invention]

This invention was made in view of the above problems, and its purpose is to provide a testing machine that can perform fatigue tests under the same conditions as when an artificial organ is attached to a human body, especially a test machine that is the same as the human body or The object of the present invention is to provide a pulsatile flow generating device for artificial organ testing that can obtain pulsatile flow similar to actual conditions, including reproduction of pathological phenomena, assuming a similar circulatory system mechanism.

[Means for solving problems]

In order to achieve the above object, the pulsatile flow generator for testing artificial organs of the present invention uses a plunger pump to send liquid stored in a tank, and the liquid discharged from the plunger pump is passed through an accumulator to the artificial organ. The present invention is characterized in that a flow passage cross-sectional area adjusting valve is provided in the return conduit for supplying the liquid to the artificial organ and guiding the liquid exiting the artificial organ to the tank.

[Effect]

When the plunger pump is driven by the drive device, the discharged liquid is sent out to the artificial organ through the accumulator while fluctuating in a constant pressure range.
The sudden pressure rise from the pump is absorbed by the accumulator, and the range of pressure fluctuation is determined by the accumulator's spring constant. Further, the reference position of pressure fluctuation at the inlet of the artificial organ can be varied by adjusting the flow passage cross-sectional area control valve, and when the flow is throttled down, the pressure in the circulation circuit increases and is maintained by the accumulator.

Furthermore, the period of pressure fluctuation can be changed by changing the rotational speed of the motor that drives the plunger pump. If the next discharge is performed before the accumulator, which has absorbed the sudden pressure increase caused by the discharge from the plunger pump, returns to its original state, a pulsating flow can be generated in the conduit, that is, the artificial organ.

〔Example〕

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

FIG. 1 is an overall schematic diagram of the apparatus according to the present invention. 1 is a liquid tank, 3 is a plunger pump,
5 is an accumulator, 7 is an artificial organ, and 9 is a valve, which are connected by a pipe 10 to constitute one circulation circuit.

The liquid 2 in the tank 1 corresponds to blood, and this tank 1 corresponds to the atrium.

The plunger pump 3 is a mechanism for feeding the liquid 2, and has a connecting rod 1 connected to a lever 15 by a crank 13 directly connected to a motor 11.
7, the plunger pump 4 is driven in a reciprocating manner to move it up and down. This plunger pump 3 also has valves 6 at the inlet and outlet of the chamber.
and a valve 8 are provided to allow flow in only one direction as shown in the figure. That is, this plunger pump 3
is equivalent to the heart in the human body.

The accumulator 5 has a spring 19 connected to one end of a load adjusting screw 20 which is screwed into and supported by a bracket 21. That is, this accumulator 5 corresponds to the elasticity of blood vessels in the human body. 7 is an artificial organ for durability testing, and a pressure gauge 30 is installed at the liquid inlet to measure the liquid P.

The valve 9 serves as an orifice provided in the conduit to expand, reduce, or adjust the cross-sectional area of the flow path through which the liquid 2 flows, and has the effect of imparting resistance to the conduit. That is, this valve 9 is for reproducing the high and low blood pressure states in the peripheral blood vessels of the human body.

In the circulation circuit configured as above, the motor 11 is driven to move up and down the plunger rod 4 of the plunger pump 3, which is rotatably pivotally connected to the end of the lever 15 via the crank 13, connecting rod 17, lever 15, etc. Discharge liquid 2. As described above, the plunger pump 3 discharges the liquid 2 from the tank 1 only in one direction of the accumulator 5, and does not allow it to flow backward. Further, by moving the fulcrum 16, the discharge amount can be changed.
The liquid 2 enters an accumulator 5 provided in the middle of the pipe line 10. This accumulator 5 has the role of absorbing a sudden pressure rise from the plunger pump 3, and the role of maintaining the pressure in the pipeline at a certain level when the liquid flow cross section of the orifice is expanded or contracted by the valve 9. do. The liquid 2 enters the artificial organ 7 and leaves this artificial organ 7 through the valve 9 into the tank 1 . When the valve 9 is throttled to reduce the cross-sectional area of the flow path, the pressure in the pipe line 10 increases, and the accumulator 5 maintains a high standard of pressure fluctuation in the pipe line.

Next, changes in the pressure P of the conduit displayed on the pressure gauge at the entrance of the artificial organ will be explained.

FIG. 2 shows changes in the pressure P of the pressure gauge 30 installed in the artificial organ 7. The amplitude L of this pressure P is determined by the spring load of the spring 19 of the accumulator 5. The load applied to this spring 19 is the screw 20
It can be changed by The period of pressure fluctuation is determined by the rotation speed of the motor.

FIG. 3 shows the state of pressure fluctuation when the rotational speed of the motor 11 is increased or decreased in the state shown in FIG. 2. By changing the rotation speed of the motor 11 in this way, the period H of pressure fluctuation can be changed.

FIG. 4 shows the movement of the reference position for pressure fluctuations. That is, when the cross-sectional area of the flow path is narrowed by the valve 9, the reference position is located upward by Z, and when expanded, it is located at the bottom.

Basically, the pressure in the flow path fluctuates as described above, but the pressure in the accumulator 5 that absorbed the sudden pressure increase due to the discharge from the plunger pump returns to its original level before the next discharge is performed. This results in a pulsatile flow. Further, the above-mentioned device is convenient because it can create pulsatile flow according to various circulatory system symptoms such as hypertension. Incidentally, in FIG. 1, the accumulator 5 may be placed between the artificial organ 7 and the valve 9.

〔Effect of the invention〕

As described in detail above, the pulsatile flow generator for artificial organ testing of the present invention uses a plunger pump to feed the liquid contained in the tank, and the liquid sent by the plunger pump is passed through the accumulator. The artificial organ is supplied, and a flow passage cross-sectional area adjustment valve is disposed in the return line that returns the liquid that has exited the artificial organ to the tank, so that the tank is connected to the atrium, the plunger pump is connected to the heart, and Since the accumulator corresponds to the elasticity of blood vessels and the flow path cross-sectional area adjustment valve corresponds to blood pressure, a pulsatile flow can be obtained with a system similar in structure and function to the human body. Furthermore, the structure is relatively simple and can be manufactured at low cost. Furthermore, with the above configuration, the characteristics of the pump and the accumulator can be changed, and a pulsatile flow that matches the current state of the human body can be obtained.

[Brief explanation of drawings]

FIG. 1 is an overall schematic diagram showing the configuration of the present invention, and FIG. 2 shows basic pressure fluctuations in a conduit, and L indicates amplitude. FIG. 3 shows changes in the period of basic pressure fluctuations in the pipeline when the rotational speed of the drive motor is changed. FIG. 4 shows changes in the reference position of basic pressure fluctuations in the pipeline when the valve opening degree is changed.
FIG. 5 is a diagram showing the principle of a roller pump. DESCRIPTION OF SYMBOLS 1...Liquid tank, 3...Plunger pump, 4...Plunger rod, 5...Accumulator, 6, 8...Valve, 9...Valve, 10...Pipe line, 11...Motor, 13...Crank, 15...
Lever for driving plunger pump, 16... Drive lever rotation fulcrum for plunger pump, 19... Spring for accumulator, 20... Adjustment screw, 21...
Adjustment screw mounting bracket, 30...pressure gauge.

Claims (1)

[Claims] 1. A circulation pipe is formed from a tank containing liquid to the tank via the artificial organ, and a plunger pump and an accumulator for liquid feeding driven by a drive device are provided in the pipe from the tank to the artificial organ. A pulsatile flow generator for testing an artificial organ, characterized in that a flow passage cross-sectional area adjusting valve is arranged in sequence and is arranged in a pipe line leading from the artificial organ to the tank.