JP3305397B2 - Blood pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood pump for use in an artificial heart, a heart-lung machine, and the like, and more particularly to a positive displacement blood pump that pumps blood by changing the volume in a housing.

[0002]

2. Description of the Related Art As a blood pump, a positive displacement blood pump which performs a pumping action by moving a volume, such as a roller pump or a pump having an artificial valve such as a sack type, a diaphragm type, or a pusher plate type,
Non-displacement type blood pumps such as a centrifugal blood pump that performs a pumping operation by centrifugal force by rotating blood are known. The latter centrifugal blood pump is disclosed in, for example,
As described in JP-A-73163, there has been proposed an apparatus in which a disc is precessed.

[0003]

However, the roller pump is not suitable for long-term use due to the durability of the tube, since the blood is pumped out of the elastic tube by the roller in order to squeeze the blood. The blood flow obtained by this pump is a continuous steady flow. On the other hand, although a pulsatile flow can be obtained with a positive displacement blood pump provided with an artificial valve, the energy conversion efficiency is low and a thrombus is easily formed around the valve. Also, since the price of the valve is high, the price of the pump alone increases. On the other hand, centrifugal pumps are designed to give a centrifugal force to blood by rotating a rotor in a housing in contact with the blood and to rotate the blood. Therefore, the centrifugal pump is small and relatively inexpensive, but is easily affected by post-load pressure. In addition, thrombus is easily generated at a seal portion around the rotation axis. Also, it is difficult to detect the blood flow rate. The blood pump described in Japanese Patent Application Laid-Open No. 3-73163 is also a centrifugal blood pump for applying a centrifugal force to blood and sending out the blood. It is difficult to detect blood flow. Moreover, the blood flow obtained by this pump is also a steady flow, and a pulsatile flow cannot be obtained.

Accordingly, an object of the present invention is to provide a small and inexpensive positive displacement blood pump having excellent energy conversion efficiency, high antithrombotic properties, and low cost.

[0005]

In order to achieve the above object, a blood pump according to the present invention comprises a drive shaft having a rotating shaft portion and a symmetrical shaft portion inclined at a constant angle with respect to the rotating shaft portion. A disk-shaped movable member rotatably supported on a symmetric shaft portion of the drive shaft and performing precession about the rotation shaft portion of the drive shaft; and a rotatable support of the rotation shaft portion of the drive shaft. A housing having a pump chamber surrounding a precession movement range of the movable member around the drive shaft, and having an inlet and an outlet opened to communicate with the pump chamber; and the housing and the movable member. And a partitioning means for partitioning the inflow port and the outflow port from the inner surface of the housing toward the drive shaft.

The gear mechanism includes a first bevel gear fixed around the drive shaft of the housing, and a second bevel gear meshed with the first bevel gear and fixed around the drive shaft of the movable member. Can be configured by

The partitioning means is constituted by a partition extending from the inner surface of the housing toward the drive shaft, and is fitted to the partition from the outer peripheral side of the movable member toward the drive shaft. It is preferable that a notch is formed in a radial direction of the movable member, the inflow port is formed on a side surface of the housing on one side via the partition wall, and the outflow port is formed on a side surface of the housing on the other side.

[0008]

In the blood pump having the above structure, the drive shaft has a rotating shaft and a symmetrical shaft forming a fixed inclination with respect to the rotating shaft, and the movable member is rotatable about the symmetrical shaft. When the drive shaft rotates, the movable member in the pump chamber undergoes precession about the rotary shaft portion when the drive shaft rotates. In this case, the movable member is rotatably supported by the symmetric shaft portion, but since the movable member is connected to the housing via the gear mechanism, it only rotates relatively to the drive shaft, It does not rotate with respect to the housing, but comes close to the inside of the pump chamber with a small linear gap, and swings smoothly while moving this linear proximity portion in the rotation direction of the drive shaft. On the other hand, for example, a notch is formed in the movable member, and a partitioning means in which a partition fitting into the notch is formed in the housing is configured. Therefore, the inflow port and the outflow port are partitioned by the partitioning means. A space between the movable member and the inner surface of the pump chamber is defined by the linear proximity portion. Thus, the blood flows into this space via the inflow port, and is reliably sent out from the outflow port by the movement of the linear proximity portion due to the precession of the movable member.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the housing of the blood pump 1 includes a case 2 and a lid 3, and a pump chamber 4 is defined by the two. Bottom surface 2a of case 2
Is formed in a truncated cone shape so as to surround a movement range of a movable member 8 described later, and the inner surface 2d is formed as a concave curved surface. A concave portion 2b is formed at the center of the bottom surface 2a, and a hole 2c is formed at the center of the concave portion 2b. A partition wall 2e is formed to extend from the inner side surface 2d of the case 2 toward the center of the pump chamber 4 and rise from the bottom surface 2a. Further, an inflow port 5 and an outflow port 6 are formed on both sides of the partition wall 2e and open to the inner side surface 2d.

The inner surface 3a of the lid 3 forming the pump chamber 4
Is formed in substantially the same shape as the bottom surface 2 a of the case 2. That is, the inner surface 3a is formed in the shape of a truncated cone, a concave portion 3b is formed at the center, and a hole 3c is formed at the center. The top surface of the partition wall 2e of the case 2 is formed to be in close contact with the inner surface 3a of the lid 3, and when the lid 3 is joined to the open end of the case 2, the pump chamber 4 is formed.

The holes 2c and 3c of the case 2 and the lid 3
Bearings 12 and 13 are fitted to the bearings, respectively.
The drive shaft 7 is rotatably supported via the second and the second 13. The drive shaft 7 has a rotating shaft portion 7a connected to the motor M, and a symmetric shaft portion 7b formed in the middle of the rotating shaft portion 7a so as to form a predetermined inclination angle α with respect to the rotating shaft portion 7a. The movable member 8 is supported on the symmetric shaft portion 7b via a bearing 11 and a bevel gear 22. The movable member 8 has a disk shape, and has a notch 8a fitted to the partition wall 2e from the outer periphery toward the center.
Is formed, and the plate surface is supported so as to be orthogonal to the axis of the symmetric axis portion 7b. Therefore, the plate surface of the movable member 8 forms an inclination α with respect to the axis of the rotating shaft portion 7a. The bevel gear 22 is annular, and its inner surface is fitted to the outer ring of the bearing 11, and its outer surface is joined to the movable member 8.
Note that the movable member 8 may be directly fitted to the outer ring of the bearing 11, and the bevel gear 22 may be joined to the plate surface of the movable member 8.

On the other hand, the crown gear 21 is accommodated in the concave portion 2b of the case 2, and is disposed so that its teeth face the direction of the lid 3, and is fixed to the bottom surface of the concave portion 2b. As is well known, the crown gear is a gear having a bevel gear with a pitch cone angle of 90 °, and is also called a crown gear. In this embodiment, the crown gear 21
An opening through which the drive shaft 7 is inserted is formed at the center of the bevel gear 2.
2 are arranged so as to mesh with each other. Thus, the gear mechanism 20 is constituted by the crown gear 21 and the bevel gear 22, and the case 2 serving as a housing is formed via the gear mechanism 20.
And the center of the movable member 8 are connected.

The gear mechanism 20 may be replaced by a gear mechanism composed of two crown gears 21 and 23 as shown in FIG. That is, the gear provided on the movable member 8 is also the crown gear 23. In FIG. 3 as well, the rotating shaft portion 7a and the symmetrical shaft portion 7b have a constant inclination angle α (the chain line in FIG. 3 indicates the central axis of both), and the crown gear 23 is crowned with the rotation of the drive shaft 7. It is configured to sequentially mesh with the gear 21.

Further, one end of the cylindrical sealing film 9a is joined to the periphery of the bevel gear 22 at the center of the movable member 8, and the other end is joined to the periphery of the concave portion 2b of the case 2. The drive shaft 7 and the gear mechanism 20 are surrounded and shielded from the pump chamber 4. Similarly, a cylindrical seal film 9b is joined between the peripheral edge of the bevel gear 22 and the peripheral edge of the concave portion 3b of the lid 3, and the drive shaft 7 and the bearings 11 and 13 are also connected to the pump chamber 4.
Shielded from

Thus, the movable member 8 always has a portion in the radial direction on both surfaces thereof, the inner surface of the pump chamber 4, that is, the bottom surface 2a of the case 2.
And a linear minute gap (hereinafter, referred to as a linear proximity portion CP) close to the generatrix of the inner surface 3a of the lid 3 as is apparent in FIG.
Is only left. For this reason, both the space above and below the movable member 8 is partitioned by the partition wall 2e and partitioned by the above-described linear proximity portion CP, and the partitioned spaces are respectively connected to the inlet 5 and the outlet 6 respectively. It will communicate.
Note that the movable member 8 may be configured to be in sliding contact with the bottom surface 2a and the inner surface 3a. Further, a bellows (not shown) may be provided between the movable member 8 and the case 2 instead of the partition wall 2e as a partitioning means without providing the notch 8a in the movable member 8.

The blood pump 1 configured as a positive displacement blood pump as described above is used for an artificial heart-lung machine, for example, as shown in FIG. That is, the drive shaft 7 of the blood pump 1 is rotated by the motor M under the control of the controller C, and blood is introduced from the vena cava of the living body H into the inflow port 5 and the pump chamber 4 through the artificial lung L, This is a system in which the fluid is sent from the outlet 6 to the aorta of the living body H.
In the blood pump 1, a pumping operation is performed as shown in FIGS.

The operation of the blood pump 1 will now be described with reference to FIGS.
Description will be made with reference to FIGS. First, when the drive shaft 7 is driven to rotate by the motor M, the rotation shaft portion 7a
1 is supported by the bearings 12 and 13 in the vertical direction in FIG. 1, and rotates about the vertical axis, but the symmetrical shaft portion 7b that forms an inclination angle α with respect to the vertical axis oscillates. On the other hand, the movable member 8 is rotatably supported by the symmetric shaft portion 7b, and the bevel gear 22 fixed to the movable member 8 is meshed with the crown gear 21. Since it is fixed, the rotational movement of the movable member 8 with respect to the case 2 is prevented. Therefore, the movable member 8 swings up and down in FIG. 1 in accordance with the swinging motion of the symmetric shaft portion 7b. Thus, the movable member 8 that relatively rotates around the symmetric shaft portion 7b
Will precess about the vertical axis (the axis of the rotating shaft portion 7a).

With the precession of the movable member 8, the linear proximity portion CP between the movable member 8 and the inner surface of the pump chamber 4 moves in the rotation direction of the drive shaft 7. Therefore, blood flows into the space between the movable member 8 defined by the partition wall 2 e and the linear proximity portion CP and the inner surface of the pump chamber 4 via the inflow port 5, and according to the rotation of the drive shaft 7. As the linear proximity CP moves, the blood in the pump chamber 4 moves toward the outlet 6. FIG. 5 shows the state of FIG. 1 and FIG. 2, wherein the end of the movable member 8 is located below the inflow port 5 and the linear proximity CP
Are located in the vicinity of the partition 2e (in FIG. 5, the partition 2e
In the figure, blood B shown by stippling
Flows into the pump chamber 4. When the drive shaft 7 rotates 90 ° counterclockwise from the position shown in FIG. 5, the left end of the movable member 8 shown in FIG. 1 moves to the center in front of FIG.
P moves downward in FIG. 5, and blood B moves to the right of the pump chamber 4 as shown in FIG. When the drive shaft 7 makes one rotation in this way, the space above the movable member 8 in the pump chamber 4 is filled with blood B as shown in FIG. When the drive shaft 7 is further rotated in the counterclockwise direction, the blood B is moved to the position shown in FIG.
As shown in FIGS.
Return to the position.

Although the above description relates to the space above the movable member 8 in the pump chamber 4, the same applies to the space below the movable member 8. That is, when the movable member 8 is at the position shown in FIG. 9, the inflow of the blood B starts from the inflow port 5, and at the position shown in FIG. 1, the blood B is filled in the lower space, and is sent out in FIGS. . In this way, the blood sent out from the upper and lower spaces joins at the outlet 6, and becomes a continuous steady flow, so that good energy conversion efficiency can be obtained. At this time, the flow rate of blood sent from the blood pump 1 has a high correlation with the rotation speed of the drive shaft 7, and the blood flow rate can be detected from the rotation speed of the drive shaft 7.
Therefore, it is not necessary to provide a flow meter separately provided in a centrifugal blood pump or the like. By driving the drive shaft 7 intermittently, a pulsating flow can be easily obtained.

As described above, the movable member 8 is
The movable member 8 does not rotate around the drive shaft 7, and a smooth precession motion is performed. That is, even if a rotational force is applied to the movable member 8 in association with the relative rotation of the drive shaft 7 with respect to the symmetrical shaft portion 7b, the rotational force is absorbed by the case 2 via the gear mechanism 20.
The end face of the notch 8a of the movable member 8 does not contact the partition 2e. In addition, the rotating portion of the drive shaft 7 includes the seal film 9a,
Since the sealing film 9a is shielded from the pump chamber 4 and only the bending in the vertical direction in FIG. 1 occurs to these sealing films 9a and 9b, a stable sealing function can be secured.

In this embodiment, since the inflow port 5 and the outflow port 6 do not directly communicate with each other, the output does not fluctuate due to the post-load pressure, and no artificial valve is required.
An inexpensive positive displacement blood pump can be configured. In addition to the fact that an artificial valve, which is one of the factors forming a thrombus, is not required, the movable member 8 does not rotate in the pump chamber 4 and the drive shaft 7 is moved by the seal membranes 9a and 9b. 4 can be completely shielded, so that it has excellent antithrombotic properties. Further, the support structure of the movable member 8 for the drive shaft 7 and the support structure for the case 2 and the lid 3 are configured as described above, and the precession movement of the movable member 8 by rotating the drive shaft 7. Thus, the blood pump can be formed in a small size.

[0022]

Since the present invention is configured as described above, the following effects can be obtained. That is, in the present invention, a positive displacement blood pump is configured with a simple structure, and a movable member is rotatably supported on a symmetric shaft portion that forms a fixed inclination with respect to a rotation shaft portion of a drive shaft. The housing and the movable member are connected via a gear mechanism, and the movable member performs a smooth precession about the rotating shaft in the pump chamber without rotating, so that the energy conversion efficiency is excellent and the anti-thrombosis is excellent. It can be formed with high efficiency, small size and low cost. Then, not only a steady flow but also a pulsating flow can be easily obtained.

In addition to forming a notch in the movable member,
In the case where the partitioning means is constituted by the partition wall fitted into the notch, the durability is excellent and the good assembling property is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of a blood pump of the present invention.

FIG. 2 is a plan view showing a state in which a lid is removed in one embodiment of the blood pump of the present invention.

FIG. 3 is a perspective view showing another embodiment of the gear mechanism of the blood pump of the present invention.

FIG. 4 is a configuration diagram showing an embodiment in which the blood pump of the present invention is applied to a heart-lung machine.

FIG. 5 is a plan view schematically showing a pump action in one embodiment of the present invention.

FIG. 6 is a plan view schematically showing a pump action in one embodiment of the present invention.

FIG. 7 is a plan view schematically showing a pump action in one embodiment of the present invention.

FIG. 8 is a plan view schematically showing a pump action in one embodiment of the present invention.

FIG. 9 is a plan view schematically showing a pump action in one embodiment of the present invention.

FIG. 10 is a plan view schematically showing a pump action in one embodiment of the present invention.

FIG. 11 is a plan view schematically showing a pump action in one embodiment of the present invention.

FIG. 12 is a plan view schematically showing a pump action in one embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 blood pump 2 case (housing), 2e partition (partition means) 3 lid (housing), 4 pump chamber 5 inflow port, 6 outflow port 7 drive shaft, 7a rotating shaft section, 7b symmetric shaft section 8 movable member, 9a , 9b Seal film 11-13 Bearing 20 Gear mechanism 21 Crown gear (first bevel gear) 22 Bevel gear (second bevel gear)

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Yusuke Abe 1-23-7 Mejirodai, Bunkyo-ku, Tokyo (56) References JP-A-4-2311065 (JP, A) JP-A-59-28967 (JP) JP-A-58-35288 (JP, A) JP-A-53-139391 (JP, A) JP-A-56-173338 (JP, U) JP-T-58-501264 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) A61M 1/10

Claims (3)

(57) [Claims] 1. A drive shaft having a rotating shaft portion and a symmetrical shaft portion having a constant inclination angle with respect to the rotating shaft portion, and a rotation shaft of the drive shaft rotatably supported by the symmetrical shaft portion of the drive shaft. A disk-shaped movable member that performs a precession movement about a portion, and a pump chamber that rotatably supports a rotation shaft portion of the drive shaft and surrounds a precession range of the movable member around the drive shaft. And a housing having an inflow port and an outflow port communicating with the pump chamber, a gear mechanism connecting the housing and the movable member, and an inner surface of the housing facing the drive shaft. A blood pump, comprising: a partition unit that partitions the inflow port and the outflow port. 2. A first bevel gear fixed around the drive shaft of the housing, and a second bevel gear meshed with the first bevel gear and fixed around the drive shaft of the movable member.
2. The blood pump according to claim 1, comprising a bevel gear. 3. The partitioning means comprises a partition extending from the inner surface of the housing toward the drive shaft, and from the outer peripheral side of the movable member toward the drive shaft so as to be fitted to the partition. A cutout is formed in the radial direction of the movable member, the inflow port is formed on a side surface of the housing on one side via the partition wall, and the outflow port is formed on a side surface of the housing on the other side. The blood pump according to claim 1, wherein