JPS62240048A - Artificial heart valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in an artificial heart valve made of an artificial material that does not easily induce a coagulation reaction in blood.

(Prior art) Artificial hearts are usually sac-type pumps, which are made up of a sac and its inflow and outflow valves. The characteristic of the sac-type pump is that one pump cycle is made during the systole and diastole, and the yield period is a phase in which the sac is pumped out using air pressure to eject blood, and it is possible to artificially create m nodes. On the other hand, during diastole, the flow phase into the sac, the atrial pressure is at most 5 to 10 m
Up to 1 g, the pressure gradient is extremely small, and even if pressure is applied to increase the pressure gradient, the blood vessel wall will simply collapse.
It is impossible to suction and inflow like an industrial pump. Therefore, in order to improve the pump performance of an artificial heart, the yield u
The most important thing is to be able to draw as much blood into the pump as quickly as possible at a low pressure gradient during the inflow phase (diastole), which is why a wide valve diameter and quick opening and closing are necessary. be. By the way, the present inventor previously proposed an artificial heart valve described in Japanese Patent Publication No. 54-42759, in which a valve seat was built into the wall of the conduit through which blood flows, and a valve ball was loosely fitted into the valve seat. Subsequent tests have shown that this valve has no thrombus formation within the valve, has good valve function in terms of quick opening and closing, and is capable of handling pulses of 400 to 500 times per minute. It is highly desirable to use this valve as an inflow valve for an artificial heart.

(Problem to be Solved by the Invention) However, this type of artificial heart valve has a characteristic associated with its shape that if the valve diameter is doubled, the valve orifice area will be quadrupled, but the valve itself and the valve ball will be 3 times larger. The volume of the valve ball increases by 8 times (see Figure 4).
As the valve ball becomes larger, the energy required to move and close it and the amount of blood flowing backward increase proportionally, making it difficult to open and close the valve, and the distance and time the valve ball travels also increases. , the pump efficiency will be greatly reduced, so the valve opening area must be expanded without increasing the size of the valve ball and prolonging the travel time of the valve ball.

(Means for Solving the Problems) The present invention relates to an artificial heart valve that solves the above-mentioned problems. A valve body is provided between the sack and the conduit, and a valve ball is loosely fitted into each valve chamber.

(Function) When such an artificial heart valve is used with the sac driven by pneumatic pressure, blood flows into the sac from one conduit for blood inflow, and then flows into the sac from the other conduit. The blood is ejected from the conduit for ejecting blood, but a valve body with a plurality of communication passages arranged in parallel is provided between the conduit and the sac, and the valve chamber of each communication passage is Since valve balls for opening and closing the communication passages are loosely fitted into the valve bodies, a large amount of blood intermittently flows through each communication passage of the valve body even during diastole when the pressure gradient is small. Moreover, since each communicating path does not need to have a large length or valve volume, the distance the valve ball moves is small and the valve ball can close the communicating path in a short time, reducing the amount of backflow blood required to move the valve ball. Since the increase remains linearly proportional to the number of communication passages, the artificial heart pump can be driven efficiently.

(Embodiment) Next, the present invention will be described in detail with reference to the illustrated embodiment.
The sac (2) is connected to a blood inflow conduit (3) and a blood ejection conduit (4) made of the same material. (5) is sack (2)
and the blood ejection conduit (4), and the cough valve body (5) is provided between the sac (2) and the conduit (3), (4).
) with multiple communication passages (6) in a short column made of the same material as
The valve seats (η
The valve chamber (9) is formed with a valve ball stopper (8) on the discharge side, and each valve chamber (9) of the valve body (5) is provided with the communication passage (6). A valve ball Ql that closes the valve seat (7) is loosely fitted.

With this configuration, when the sac (2) of the pulsating artificial heart pump (1) is pressurized by a drive device (not shown) during the systole, blood flows into the sac through the inflow conduit (31). (2) The blood that was filled in the valve ball stopper (8) is removed from each valve ball (II) placed in the valve body (5) with the valve ball (II) in contact with the valve seat (7). Since the communication path (6) is blocked, the blood in the sac (2) will flow out to the blood ejection conduit (4), and
During diastole, blood with a small pressure gradient flows from the atrium into the sac (2) via the blood inflow conduit (3).

However, the valve body (5) has a plurality of communication passages (
6), as shown in Figure 5, if the total cross-sectional area of the communication port (6) is large, a large amount of blood will flow through the sac (venous pressure) even though the pressure gradient (venous pressure) is small. 2) It will flow into the area in a short period of time. By enlarging the inner diameter of one communication passage (6), the inflow amount equivalent to this can be increased by enlarging the inner diameter of one communication passage (6).
If you want to increase the cross-sectional area of 6), for example, by doubling the inner diameter, the valve ball (II
The diameter of the valve body (5) also doubles, and the length of the valve body (5) also doubles.

As a result, the stroke of the valve ball α within the valve body (5) is also doubled, increasing the opening and closing time of the valve. However, in the present invention, which attempts to increase the cross-sectional area of the communication passages (6) by increasing the number of communication passages (6) without changing the inner diameter, if each communication passage (6) has the same inner diameter, aisle(
6) The increase in the number of valves does not increase the opening/closing time of the valves, and therefore, the pulsation rate does not decrease and the efficiency of the artificial heart pump (1) becomes high. In addition, in the present invention, the amount of blood backflow required for the valve closing operation is slightly increased compared to the previously proposed method, but in basic fishing, the amount of blood backflow in this type of valve is extremely small. By enlarging the diameter of the valve and increasing the valve opening area, there is no problem in practical use since the amount is much smaller than when using a large valve ball.In addition, in the example, the valve ball stop +
In 81, semicircular stoppers are formed on the left and right sides at the bottom of the valve body (5), and a single-character-shaped passage is provided in the center, but the shape of the passage may be cross-shaped or Y-shaped, and the valve ball Of course, any material may be used as long as it stops the movement of the alpha wound and does not impede blood flow, and the number of communicating holes (6) is also limited to seven as shown in the examples. There may be at least two or more, but any number may be used as long as it can be implemented, and the arrangement pattern is also free.

(Effects of the Invention) As is clear from the above description, the present invention provides a means for increasing the amount of blood ejected without increasing the inner diameter of the communication passage.
Since the number of communication passages is increased, the length of the valve chamber corresponding to the amount of movement of the valve ball does not increase, and therefore the opening and closing time of the valve changes.Moreover, the speed required to move the valve ball does not increase. The increase in blood flow volume is one-dimensional and does not increase two-dimensionally or three-dimensionally like when the inner diameter of the communication passage is increased, and there is almost no deterioration in valve function. In addition, since multiple valve chambers are formed in the valve body, the outer wall of the valve chamber is shared by each valve chamber, making the valve smaller and eliminating the problems of conventional artificial heart valves. The benefits it brings to medicine are enormous.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view showing an embodiment of the present invention, Fig. 2 is a partially cutaway front view, and Fig. 3 is the same (partially cutaway plan view). Graph showing increase rate of ball volume, cross-sectional area of communication path, and valve ball diameter, 5th
The figure is a graph showing the relationship between venous pressure and blood volume with respect to the total cross-sectional area of the communication passage. (2): Sac, (3): Conduit for blood inflow, (4):
Conduit for blood ejection, (5): Valve body, (6): Communication path, α
l: Valve ball. FA1 Figure 2 Figure 2 Figure 3 Figure 4 Figure 8 10 12 14 16 (Ugly) A8 raw of communication path

Claims (1)

[Claims] For an artificial heart, characterized in that a valve body comprising a plurality of communicating passages each having a valve chamber arranged in parallel is provided between a sac and a conduit, and a valve ball is loosely fitted into each valve chamber. valve.