JP2001245969A - Artificial heart and artificial heart driving means - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an artificial heart easily transplantable to the human body because of its small volume of a pump as a whole. SOLUTION: Inside a pump casing 1, a diaphragm 2 demarcating a pump chamber 10 connected to input and output ports Pa, Pb, a pressing plate 3 brought into plane contact with the diaphragm 2, a cam 4 pressing when the pressing plate 3 is turned, and a supporting shaft 5 rotating the cam 4 are arranged, while a motor M is arranged apart from the pump casing 1, and the supporting shaft 5 and an output shaft of the motor M are connected together via a torque transmittable control cable 6. Even when the pump casing 1 is installed to the human body separately from the motor M, the cam 4 can be rotated through a control cable 6 for driving the pump. The size of the artificial heart can be reduced because the motor M is not included in the pump casing 1, and the artificial heart can be easily transplanted into the human body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an artificial heart and artificial heart driving means. More specifically, the present invention relates to a driving mechanism of an artificial heart.

[0002]

2. Description of the Related Art As a prior art relating to a driving mechanism of an artificial heart, Japanese Patent Publication No. Hei 10-513372 and a paper "Artificial Heart and Assist Devices: New Develop"
ments at the Helmholtz Institute ". In each of these, a drive unit and a drive mechanism such as a gear and a pressing plate are incorporated in a pump unit. That is, as a representative of the latter conventional example, as shown in FIG. 3, a diaphragm 52 is disposed in a casing 51 and a pressing plate 54 is provided on the side opposite to the pump chamber 53.
And a motor / gear mechanism 55 for pressing the pressing plate 54.

[0003]

As described above, in the conventional example, the gear and the motor are housed in the same casing 51, so that the volume of the entire pump is considerably large. In addition, it is difficult to implant them in a human body.

[0004] In view of such circumstances, an object of the present invention is to provide an artificial heart in which the volume of the entire pump is small and which can be easily implanted in a human body.

[0005]

The artificial heart according to claim 1 comprises:
In the pump casing, a diaphragm that defines a pump chamber connected to the input / output port, a pressing plate that is in surface contact with the diaphragm, a cam that presses by rotating the pressing plate, and a spindle that rotates the cam are provided. A motor is provided apart from the pump casing, and the support shaft and an output shaft of the motor are connected by a control cable capable of transmitting torque. In the artificial heart according to a second aspect, in the invention according to the first aspect, the support shaft and the control cable are connected by a joint capable of one-touch connection, and the control cable and the output shaft of the motor are connected to each other so that their axes are aligned with each other. It is characterized by being connected by a flexible joint capable of transmitting torque even when crossed. According to a third aspect of the present invention, the artificial heart driving means is characterized in that a control cable capable of transmitting torque and flexibly bent and a cam for driving the artificial heart is attached to one end of the control cable.

According to the first aspect of the present invention, even if the pump casing and the motor are separated and attached to a human body, the pump can be driven by rotating the cam with the control cable. And since a motor is not put into a pump casing, it can be made small and implantation is easy. According to the second aspect of the present invention, the flexibility of the flexible joint can increase the degree of freedom of the arrangement position of the motor, and the quick joint allows the motor to be smoothly attached and detached. . According to the invention of claim 3, the arrangement of the artificial heart main body and the motor can be freely selected by the flexibility of the control cable, so that the handling becomes easy.

[0007]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of the artificial heart of the present embodiment. Although the artificial heart of this embodiment has a pair of pumps, only one side is shown in the drawings. In FIG. 1, reference numeral 1 denotes a casing of the pump of the artificial heart according to the present embodiment. This pump casing 1
Is made of a polymer material such as polyurethane or silicon. The pump casing 1 includes a pair of pumps inside, and one of the pumps is provided with an input port Pa connected to the left atrium and an output port Pb connected to the aorta. The other pump (not shown) is provided with an input port Pa connected to the right atrium and an output port Pb connected to the pulmonary artery. The input port Pa is provided with a check valve (not shown) so that blood flows only from the left atrium (right atrium) to the pump casing 1. The output port Pb is provided with a check valve (not shown) so that blood flows only from the pump casing 1 toward the aorta (pulmonary artery).

Next, the construction of the pump will be described. Since the construction of a pair of pumps is the same, only one of the pumps will be described.

A diaphragm 2 is provided inside the pump casing 1. This tire flam 2
It is a thin film made of a polymer material such as polyurethane or silicon, which can expand and contract freely. The diaphragm 2 is installed in the pump casing 1 in a stretched state.
The inside of the pump casing 1 is defined as a pump chamber 10 and an air chamber A connected to a pair of input port Pa and output port Pb.

In the air chamber A, the diaphragm 2 is provided.
A pressing plate 3 is provided so as to make surface contact with the pressing plate 3. The pressing plate 3 is made of, for example, an alloy or a ceramic containing oil, has elasticity, and has a regular circular shape.

A support shaft 5 is provided in the air chamber A. The support shaft 5 is rotatably supported by the pump casing 1. A base end of the cam 4 is attached to one end of the support shaft 5 so as to be orthogonal to the support shaft 5. The cam 4 is an elliptical member whose material is, for example, ceramic or a composite material of ceramic and alloy.
The length of the cam 4 from the base end to the tip is longer than the distance between the support shaft 5 and the pressing plate 3. For this reason,
When the cam 4 is rotated together with the support shaft 5, the tip of the cam 4 is rotated while contacting the pressing plate 3, and the pressing plate 3 can be pressed by the cam 4.

Outside the pump casing 1, a cylindrical portion (not shown) having an external thread formed on the outer periphery is formed. In this cylindrical portion, a through-hole penetrating the inner surface and the outer surface of the pump casing 1 is formed. The other end of the support shaft 5 protrudes outside the pump casing 1 through the through hole. At the other end of the support shaft 5, for example, a hexagonal hole is formed.

One end of a control cable 6 is attached to the other end of the support shaft 5. The control cable 6 is made by inserting a flexible wire cable into a flexible synthetic resin outer tube and rotatably supporting the cable. At one end of the control cable 6, for example, a hexagonal projection is formed. Also, at one end of the outer tube of the control cable 6,
A well-known nut is attached. The cylindrical portion on the outer surface of the pump casing 1, the nut of the control cable 6, the hexagonal hole at the other end of the support shaft 5, and the hexagonal projection at one end of the control cable 6 are defined in the claims. The joint 7 is constituted. For this reason, the hexagonal protrusion at one end of the control cable 6 is fitted into the hexagonal hole at the other end of the support shaft 5, and the nut of the control cable 6 is screwed into a male screw on the outer periphery of the cylindrical portion. With only this, the support shaft 5 and the control cable 6 can be connected. Furthermore, when the nut of the control cable 6 and the external thread on the outer periphery of the cylindrical portion on the outer surface of the pump casing 1 are screwed together, the connecting portion is configured to be liquid-tight.
The joint 7 does not need to have the above-described configuration, and may be any as long as it can connect the support shaft 5 and the control cable 6 in a liquid-tight manner.

A main shaft of the motor M is attached to the other end of the control cable 6 via a flexible joint 8. The flexible joint 8 is, for example, an Oldham joint. Therefore, torque can be transmitted even if the axis centers of the control cable 6 and the main shaft of the motor M are shifted or cross each other, and the joint can be shortened. Therefore, the degree of freedom of the arrangement position of the motor M can be increased. As the flexible joint 8, any joint that can transmit torque even when the center of the axis of the control cable 6 and the axis of the main shaft of the motor M are shifted or cross each other can be adopted.

A control box CB containing a power supply is connected to the motor M. The control box CB supplies a current to the motor M and adjusts the frequency and the like of the current to control the rotation speed of the motor M. Furthermore, the amount of blood flowing into the pump can be predicted from the change in the load current to the motor M, and the number of rotations can be controlled. Further, the motor M and the control box CB are housed in an integral case, forming one control unit CU.

Next, the operation and effect of the artificial heart of the present embodiment will be described. First, one input port Pa is connected to the left atrium, and one output port Pb is connected to the aorta. Next, the other input port Pa is connected to the right atrium, and the other output port Pb is connected to the pulmonary artery. Then, the pump casing 1 is implanted in the chest of the human body.

Next, the control unit CU is implanted in the abdomen, one end of the control cable 6 is penetrated through the diaphragm, and one end of the control cable 6 is brought close to the pump casing 1. Axis 5
When it is attached to the other end of the artificial heart, the implantation of the artificial heart is completed.

FIG. 2 is an explanatory diagram of the pump operation of the artificial heart according to the present embodiment. Although the pumps are provided on the left and right with the support shaft 5 interposed therebetween, FIG. 1 shows only the movement of one of the pumps. The cam 4 is shown in a simplified form to make its operation easier to understand. When the control box CB is turned on and the motor M is operated, the rotational torque of the motor M is transmitted to the support shaft 5 by the control cable 6, and the cam 4 rotates.

When the cam 4 rotates, the tip of the cam 4 comes into contact with the pressing plate 3 of one of the pumps (see FIGS. 2 (I) and (II)). When the cam 4 further rotates, the cam 4 pushes one pressing plate 3 outward. Then, the diaphragm 2 is pushed and extended by the one pressing plate 3, and the one pump chamber 10 becomes smaller, so that the blood filled in the pump chamber 10 is pushed out from the output port Pb (FIG. 2 (III)). reference). At this time, the inside of the air chamber A has a negative pressure because the air chamber A is expanded by reducing the size of one of the pump chambers 10.

When the cam 4 further rotates, the tip of the cam 4 moves along one pressing plate 3 and separates from the pressing plate 3 (see FIGS. 2 (IV) and 2 (V)). Then, the one diaphragm 2 returns to the original state due to the negative pressure inside the air chamber A or the contraction force of itself, so that the one pump chamber 10 expands and the one pump port 10 Blood flows into 10. In addition, the one pump chamber 10 is expanded by the venous pressure of the inflowing blood, so that the one pump chamber 10 is filled with sufficient blood.

When the cam 4 further rotates from the state shown in FIG. 2 (V), the tip of the cam 4 comes into contact with the pressing plate 3 of the other pump (not shown), and the other pressing plate 3 In the pump chamber 10 is pushed out from the other output port Pb.

When the cam 4 further rotates, the other diaphragm 2 returns to its original state due to the negative pressure inside the air chamber A or the contracting force of the other diaphragm.
0 spreads, and blood flows into the other pump chamber 10 from the other input port Pa.

When the cam 4 further rotates, the state returns to the state shown in FIG. 2 (I), and the other diaphragm 2 is pushed again by the cam 4.

Therefore, the above operation is repeated by the continuous rotation of the cam 4, and the pump chambers 10 of the pair of pumps alternately expand and contract alternately.
The blood flowing from a can be sent out from the output port Pb into the body.

The artificial heart needs to be replanted, for example, every 5 to 6 years. At this time, the spindle 5 and the control cable 6 can be detached by the quick coupling 7, and the pump casing 1 and the control unit CU can be separately taken out. Then, the pump casing 1 and the control unit CU are separately implanted in the human body,
The artificial heart can be replaced simply by attaching one end of the control cable 6 to the support shaft 5 by the quick coupling 7.

Therefore, according to the artificial heart of this embodiment,
The pump casing 1 is separated from the motor M, and the pump casing 1 is implanted in the chest.
Even if U is implanted in the abdomen, the cam 4 can be rotated by the control cable 6 to drive the pump. Since the motor M is not inserted into the pump casing 1, the pump casing 1 can be reduced in size, and can be easily implanted. In addition, the flexibility of the flexible joint 8 can increase the degree of freedom of the arrangement position of the motor M and the control unit CU, and the quick joint 7 allows the attachment and detachment to be performed smoothly, so that the operation of replacing the artificial heart is easy and quick. I can do it.

[0027]

According to the artificial heart of the first aspect, the pump can be driven by rotating the cam with the control cable even if the pump casing and the motor are separated and attached to the human body.
And since a motor is not put into a pump casing, it can be made small and implantation is easy. According to the artificial heart according to the second aspect, the flexibility of the flexible joint can increase the degree of freedom of the arrangement position of the motor, and the quick joint allows the attachment and detachment to be performed smoothly. Can be done. According to the artificial heart driving means of claim 3, the arrangement of the artificial heart main body and the motor can be freely selected by the flexibility of the control cable, so that the handling becomes easy.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an artificial heart according to an embodiment.

FIG. 2 is an explanatory diagram of a pump operation of the artificial heart according to the present embodiment.

FIG. 3 is a schematic explanatory view of an artificial heart having a similar structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump casing 2 Diaphragm 3 Press plate 4 Cam 5 Support shaft 6 Control cable 7 Joint 8 Flexible joint M Motor Pa Input port Pb output port

Claims (3)

[Claims] 1. A diaphragm defining a pump chamber connected to an input / output port in a pump casing, a pressing plate in surface contact with the diaphragm, a cam pressing by rotating the pressing plate, and rotating the cam. An artificial heart, wherein a support shaft is provided, and a motor is provided apart from the pump casing, and the support shaft and an output shaft of the motor are connected by a control cable capable of transmitting torque. 2. The method according to claim 1, wherein the support shaft and the control cable are
The control cable and the output shaft of the motor are connected by a one-touch connectable joint, and the control cable and the output shaft of the motor are connected by a flexible joint capable of transmitting torque even when their axes cross each other. Artificial heart. 3. An artificial heart driving means comprising a control cable capable of transmitting torque and flexibly bent, and a cam for driving an artificial heart attached to one end of the control cable.