JPH05111534A - Blood pump - Google Patents

Abstract

PURPOSE:To provide a small-sized, lightweight blood pump reducing the occurrence of hemolysis and capable of being safely used over a long period by providing a follower supported by a support shaft erected on a bulkhead in the point contact state and in the floated state from the bulkhead and having a blood flow passage penetrated upward from the lower face of a pedestal. CONSTITUTION:A follower 10 constituted of a pedestal 8 erected with many blades on the upper face and coupled with a lower cover on the lower side and the first magnet 11 fitted in the lower cover is arranged in the first housing 1. The bottom face of the pedestal 8 is set to the size nearly covering the upper face of a bulkhead 3, and a spherical body 12 is arranged at the center section. A support shaft 3a is erected at the center section of the bulkhead 3, the spherical body 12 is located in the recess of a top face, thus the point contact between the spherical body 12 and the support shaft 3a is realized. A blood flow passage communicated from the upper side of the pedestal 8 to a blood discharge port 6 via a through hole 13 and a fine gap between the lower cover and the bulkhead 3 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood pump, and more particularly, it is small in size and light in weight and has less hemolysis.
The present invention relates to a blood pump that can be safely used for a long period of time and is suitable for use in an extracorporeal circulation circuit such as a heart-lung machine or a cardiac assist circulation device after open heart surgery.

[0002]

2. Description of the Related Art Conventionally, as a blood pump for an extracorporeal circulation circuit such as a heart-lung machine or a heart assisting circulatory apparatus after open heart surgery, a pulsatile pump type and a smooth pump for supplying pulsatile flow are used. In addition to the roller pump type that supplies a flow, a centrifugal pump type blood pump is known. As a conventional centrifugal pump-type blood pump, those mainly shown in FIGS. 2 and 3 are known.

The blood pump shown in FIG. 2 has a conical upper end surface in the space of the housing 26 and the housing 26.
Is provided with an impeller composed of a cylindrical pedestal 21 having a bottom surface having a diameter much smaller than the diameter of and a plurality of blades 22 radially provided on the outer peripheral surface thereof, and when the shaft 24 is rotated by a motor (not shown), It has a structure in which blood flows like a blood stream 23 in the figure. However,
This blood pump has a vortex flow 25 near the outer periphery of the base 21.
Occurs, and a very large stress is applied to the blood cells, resulting in the problem that the blood cells are destroyed and hemolysis occurs.

On the other hand, in the blood pump shown in FIG. 3, the pedestal 2 having a substantially conical shape as a whole in the space of the housing 29.
7 and a plurality of plate-shaped blades 28 radially provided on the curved surface thereof at a position apart from the apex of the pedestal 27 by a certain distance. When the shaft 30 is rotated by a motor (not shown), Is a structure that flows like a blood flow 31 in the figure. In this blood pump, the bottom surface of the pedestal 27 houses the pedestal 27.
Since it has an area that covers almost the entire inner bottom surface of 2,
No eddy current is generated as in the blood pump shown in FIG.

However, even with this blood pump, there are pulsations in which the occurrence of hemolysis cannot be effectively suppressed to a satisfactory level, and the blood discharge efficiency is also insufficient. Further, since the blade 28 is a curved plate (as viewed from above), there is a problem that it is difficult to manufacture it when integrally forming with the pedestal 27.

In the blood pump shown in FIGS. 2 and 3, a ball bearing is required to fix the shafts 24 and 30. However, when a ball bearing is used, the ball bearing comes into contact with blood, which changes the lubrication environment in the bearing, which causes a problem that the lubrication performance of the ball bearing deteriorates rapidly with repeated use of the blood pump. It was In order to solve this problem, it was considered to use a sealing material such as packing instead of the ball bearing. However, it has also been found that even if the sealing material is used, a new problem arises that blood leaks from the sealing portion while the blood pump is used for a long period of time. Therefore, when using a blood pump that uses a sealant in order to solve the problems caused by the use of ball bearings, it is unavoidable to replace the blood pump that is in use at an appropriate time before the leakage of blood occurs. .. However, such frequent replacement of the blood pump is complicated and impractical.

The present invention has been made to improve the above circumstances. That is, the object of the present invention is that the occurrence of hemolysis is small, it is small and lightweight, it can be safely used for a long time, and it is suitable for an extracorporeal circulation circuit such as a heart-lung machine or a cardiac assist circulation apparatus after open-heart surgery. It is to provide a centrifugal pump-type blood pump that can be used for.

[0008]

According to the present invention for solving the above-mentioned problems, a blood discharge hole having a blood introducing hole at its top and opening at a side in a direction orthogonal to the opening direction of this blood introducing hole is provided. A first housing including: a second housing provided with a partition wall between the first housing chamber and the first housing chamber;
A second driving member provided in the second housing, having a second magnet arranged at one end side facing the partition wall and having a connecting portion for connecting a drive source at the other end side; A plurality of blades are provided on the upper surface facing the blood introduction hole of the pedestal rotatably supported in a point contact state by a support shaft standing on the partition wall facing the inside of the housing and arranged in a non-contact state with the partition wall. And a follower provided with a first magnet corresponding to the second magnet and having a blood flow passage that penetrates from the lower surface to the upper surface of the pedestal so as to discharge blood around the support shaft. It is a blood pump.

[0009]

The present invention will be described in detail below. In the blood pump of the present invention, the rotation of the driven body composed of the pedestal and the vanes is between the second magnet attached to the driving body connected to the drive source outside the second housing chamber and the first magnet attached to the pedestal. Unlike the conventional case, the pedestal does not have a rotating shaft connected to an external drive source, and the first housing and the second housing are separated by a partition wall. Therefore, there is no possibility that the blood in the first housing will leak out of the first housing.

Further, the pedestal is supported by a support shaft standing upright from the partition wall in a point contact state and in a state of floating above the partition wall, and the peripheral surface of the support shaft and the pedestal from the upper surface of the pedestal. Since the blood flow passage leading to the blood discharge hole through the lower surface is formed, the retention of blood occurring between the pedestal and the upper surface of the partition wall is reduced, and the accumulation of heat in the blood due to the rotation of the blade is also reduced. As a result, the hemolysis phenomenon can be reduced. Further, since the bottom surface of the pedestal is formed so as to cover almost the entire bottom surface of the first housing chamber, the flow of blood is made smooth, and no swirl of blood is generated,
It is possible to reduce stress due to, for example, a shearing force or a vortex applied to the blood flowing in the blood pump.

[0011]

EXAMPLE As shown in FIG. 1, the blood pump of this example comprises a first housing 1 and a second housing 4 which is adjacent to the first housing 1 via a partition wall 3. The first housing 1 and the second housing 4 are detachably coupled.
The mechanism of coupling the first housing 1 and the second housing 4 is as follows.

That is, as shown in FIG. 4, one half of the peripheral side surface of the second housing 4 extends slightly further in the axial direction than the other half, and the tip end surface of the second housing 4 extends in the axial direction of the second housing 4. The connecting groove 4a is formed by bending the connecting groove 4a into a groove, and the end surface 4b of the second housing 4 facing the connecting groove 4a is
A coupling pin 4c is provided. The coupling pin 4c projects from the end surface 4b of the second housing 4 by being constantly biased by a biasing member (not shown), and the coupling pin 4c is resisted against the biasing member by operating the operation button 4d. It can be retracted into the end face 4b.

Further, the first housing 1 is provided with a fitting portion 1a which fits in the coupling groove 4a at its tip portion, and the coupling pin 4c is provided at the tip surface of the first housing 1.
Is formed by opening a coupling hole 1b into which is inserted. The first housing 1 can be integrally coupled with the second housing 4 by fitting the fitting portion 1a into the coupling groove 4a of the second housing 4 and inserting the coupling pin 4c into the coupling hole 1b. ..

The first housing 1 is sterilized before use, and the first housing 1 is discarded after being used integrally with the second housing 4. That is,
The first housing 1 may be a disposable product. Further, since the second housing 4 does not have a site that comes into contact with blood, it is not particularly sterilized before use, and even after being used in combination with the first housing 1, It can be used again and again as many times as needed. The mechanism for coupling the first housing 1 and the second housing 4 is the same as in FIG.
Not limited to the mechanism shown in (1), various mechanisms can be appropriately adopted.

By the way, the first housing 1 is provided with a blood inlet 5 at the top and a blood outlet 6 opening at a side orthogonal to the opening direction of the blood inlet 5 at the side. Inside the first housing 1, a pedestal 8 having a large number of blades 9 having a truncated cone shape and arranged in a circular shape on the upper surface, and a circular dish-shaped lower cover 8a fitted on the lower surface side, and a pedestal 8 below the pedestal 8. A driven body 10, that is, an impeller composed of a circularly arranged first magnet 11 mounted in the cover 8a is arranged.

The size of the bottom surface of the pedestal 8 is a size that covers substantially the entire bottom surface of the first housing 1, that is, the partition wall 3
The size is set to substantially cover the upper surface of the. Further, inside the center of the pedestal 8, the upper half is fitted in a hemispherical recess provided in the pedestal 8, and the lower half is directed toward the shaft support cylinder 8b provided in the central portion of the lower cover 8a. The exposed sphere 12 is arranged. And in the peripheral area of this sphere 12,
A required number of through holes 13 are provided so as to penetrate from the upper surface of the pedestal 8 to the shaft support cylinder 8b side. In addition, the shaft support cylinder 8
A cylindrical slide bearing 14 is attached to b.

At the center of the partition wall 3, a support shaft 3a extending to substantially the upper end of the cylindrical slide bearing 14 is erected with a minute gap between the support shaft 3a and the inner peripheral surface of the slide bearing 14. There is. The top surface of the support shaft 3a is slightly concave, and the spherical body 12 is located in the concave surface so that point contact between the spherical body 12 and the support shaft 3a is achieved and the driven body is driven. The sphere 12 does not deviate from the top surface of the support shaft 3a during rotation.

The sliding bearing 14 is made of ceramics, preferably Si ₃ N ₄ . With such a structure, the pedestal 8 is rotatably supported by the support shaft 3a in a point contact manner and in a state of being separated from the partition wall 3, and the pedestal 8 has an upper surface through the through hole 13 A blood flow passage, which is shown by a dotted line in FIG. 1, is formed so as to communicate with the blood discharge port 6 through the minute gap, the space between the lower cover 8a and the partition wall 3.

On the other hand, the second housing 4 has a rotary shaft 15
A ring-shaped second member is provided on the upper end of the disk through a disk-shaped support member 15a.
A prime mover 18 is integrally mounted so that the magnet 16 and the back yoke 17 face the first magnet 11. The rotating shaft 15 is rotatably supported inside the second housing 4 by a lower bearing 19, and its rear end is exposed to the lower end side of the second housing 4 and a driving source such as a motor via a flexible shaft (not shown). (Not shown).

In the above structure, when the drive source is started, the rotary shaft 15 rotates, and the second magnet 16 attached thereto also rotates. Then, the second magnet 16 and the first
A magnetic force (attracting force) acts between the first magnet 1 and the magnet 11 as the second magnet 16 rotates.
1 also rotates. That is, the driven body 10 also rotates together with the first magnet 11, whereby the blood introducing port 5
Is introduced into the first housing 1, and is discharged to the blood discharge port 6 by the blades 9 of the driven body 10.

As is apparent from the above structure, in this embodiment, unlike the conventional example, the driven body 10 is completely separated from the driving body 18 by the partition wall 3, so that the rotary shaft as in the conventional example. The hemolysis phenomenon caused by the rotation of the is eliminated or significantly reduced. Further, since the pedestal 8 is provided with the above-described blood flow passage, it is possible to prevent blood from staying between the lower surface of the pedestal 8 and the upper surface of the partition wall 3 and to smoothly discharge blood. Further, since the slide bearing 14 is made of ceramics, it is possible to realize excellent rotation resistance and smooth rotation of the driven body without requiring lubricating oil.

The present invention is not limited to the above embodiment,
It is possible to carry out various modifications without departing from the scope of the invention. For example, the first magnet is
Besides the arrangement shown in FIG. 1, it is also possible to fix it to the lower surface of the pedestal 8. As the structure of the blade, a conventionally known structure can be applied to the present invention, and a cone other than the truncated cone can be used as the shape of the pedestal. An inverted conical body may be used instead of the spherical body 12.

[0023]

According to the blood pump of the present invention, the follower is completely separated from the prime mover, and since the blood flow passage is formed in the pedestal of the follower, hemolysis can be significantly reduced. .. Further, since it is small and lightweight and has a structure that does not easily break down, it can be used safely for a long period of time.

Therefore, it is very suitable for use in an extracorporeal circulation circuit such as a heart-lung machine or a heart assist circulation device after open heart surgery.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view showing an embodiment of a blood pump of the present invention.

FIG. 2 is a sectional view showing a main part of a conventional blood pump.

FIG. 3 is a cross-sectional view showing a main part of another conventional blood pump.

FIG. 4 is a perspective view showing a mechanism of coupling the first housing and the second housing.

[Explanation of sign]

 DESCRIPTION OF SYMBOLS 1 1st housing chamber 3 Partition wall 4 2nd housing chamber 8 Base 9 Blade 10 Follower 11 First magnet 13 Blood circulation hole 14 Rotating shaft 16 Second magnet 18 Primer

Claims (3)

[Claims] 1. A first housing having a blood introducing hole at the top and a blood discharging hole opening at a side in a direction orthogonal to the opening direction of the blood introducing hole, and to the first housing chamber. A second housing provided with a partition wall between them, and a second magnet provided inside the second housing, the second magnet being arranged to face the partition wall at one end side, and the drive source being connected to the other end side. And a pedestal that is rotatably supported in a point contact state by a supporting shaft that is erected on the partition wall facing the first housing and that is arranged in a non-contact state with respect to the partition wall. A plurality of blades are provided on the upper surface facing the blood introducing hole, and a first magnet corresponding to the second magnet is provided, and a blood flow passage that penetrates from the lower surface of the pedestal to the upper surface to discharge blood around the support shaft is provided. Prepare And a follower. 2. The blood pump of claim 1, wherein the pedestal is frustoconical with a bottom surface that substantially covers the entire bottom surface of the first housing chamber. 3. The blood pump according to claim 1, wherein the first housing and the second housing are detachably assembled.