JPH06218043A - Blood pump - Google Patents

Abstract

PURPOSE:To provide a blood pump which eliminates leakage of blood from a pump chamber and the like by a method where a plurality of blades are erected on the top surface of a rotary base and an impeller is arranged in the pump chamber as containing a magnet which makes the rotary base rotatable with the rotation of an external magnetic body. CONSTITUTION:An impeller 3 in a pump chamber 2 of a blood pump 1 has a rotary base 5 and an impeller 6 and a magnet plate 7 is arranged in the rotary base 5 circular centered around a rotating shaft within a plane parallel with the bottom surface of the rotary base 5. A first holding member 19 is supported on the bottom surface in the pump chamber 2 with an inclined supporting member 20 and a second holding member 21 is suspended wish a slant suspension member 22 near an opening of a blood introduction pipe 14 in a conical internal space. Then, the impeller 3 supports a lower hemispherical part 11 with the first holding member 19 in a linear contact while supporting a hemispherical top part by a second holding member 21 in a linear contact to be mounted in the pump chamber 2 free to turn. Then, the rotary base 5 is rotated at a high speed by a driver provided externally by a magnet coupling system.

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 to a blood pump which can be smoothly operated for a long period of, for example, 2 weeks or more.

[0002]

2. Description of the Related Art Conventionally, as a blood pump, a pump having a structure shown in FIGS. 2, 3 and 4, for example, is known.

In any of the blood pumps shown in FIGS. 2 to 4, a rotary pedestal having an impeller or a cone on the upper surface is provided in the pump chamber, and the rotary pedestal is rotated by a magnetic coupling system.

In particular, in the blood pump 50 shown in FIG. 2, the rotary base 51 itself is not provided with a magnet, and the rotary base 5 is
In order to rotate 1 by the magnetic coupling method,
A rotary body equipped with a magnet 54 is arranged in a rotary body chamber 53 that is a room different from the pump chamber 52 that houses the rotary base 51. The rotary shaft 55 of the rotary base 51 and the rotation of the rotary body. The shaft 56 is common. Therefore, in the blood pump 50, the rotation shaft 5 of the rotation base 51 is
5 and the rotary shaft 56 of the rotary body are one rotary shaft, and this single rotary shaft penetrates from the bottom surface of the pump chamber 52 into the rotary body chamber 53. In this blood pump, a seal member 57 is attached to the rotary shaft on the pump chamber side in order to improve the sealing property of the rotary shaft penetrating from the bottom surface of the pump chamber 52 into the rotary body chamber 53.

However, even though the sealability of the rotary shaft is improved, the seal is not perfect,
When the blood pump is continuously operated for a long period of time, blood leaks from the seal portion of the rotating shaft into the rotating body chamber. Such leakage of blood causes coagulation of blood in the bearing portion 58, which causes an overload on the rotation shaft, and eventually impedes smooth rotation of the rotation base 51. That is, the failure of the blood pump 50 is induced.

The blood pump 60 shown in FIG.
A magnet 64 for rotating in a magnet coupling system is mounted on a rotary pedestal 63 which is arranged in the first unit and has a cone 62 on the upper surface. This blood pump 60
Is rotatably supported by a rotary shaft 65 provided upright in the pump chamber 61 through a bearing 66, and the rotary pedestal 63 is rotatably supported by the bearing 66 in order to prevent blood from entering the bearing 66. A seal portion 67 is provided.

However, even in the blood pump shown in FIG. 3, the seal of the seal portion is not perfect, and if the blood pump is operated for a long time, blood leaks from the seal portion, and the leaked blood leaks to the bearing portion or the like. Solidifies, which overloads the rotating pedestal and eventually shuts down the blood pump. In addition, blood may leak from the shaft hole in which the rotary shaft 65 is inserted, which causes the same problem as described above.

The blood pump 70 shown in FIG. 4 has a rotating shaft 71.
One end of which is inserted into the pump chamber 72 and the other end of which is inserted into the rotating body chamber 73, and the impeller 74 having a plurality of blades is fixed to the tip of the rotating shaft 71 in the pump chamber 72. Rotating disk 7 in which magnet 75 is attached to the rotating shaft in chamber 73
6 are connected. A mechanical seal is formed by a combination of the seal rotor 77 fixed to the rotary shaft 71 and the seal stator 79 fixed to the pump housing 78.

However, even in the seal structure of the blood pump shown in FIG. 4, since the mechanical seal is formed by the surface contact between the seal rotor 77 and the seal stator 79, the seal rotor 77 and the seal stator are accompanied by the operation of the pump. 79 wear progresses. Due to the progress of this wear, the smoothness and flatness of the surface contact portion are lost, and blood leaks from the pump chamber to the rotor chamber. As in the case of the blood pump shown in FIGS. 2 and 3, the leaked blood reaches the bearing portion and causes blood to coagulate there, which impedes smooth rotation of the rotary plate 76.

Further, the blood pumps shown in FIGS. 3 and 4 have a problem that blood easily accumulates between the bottom surface of the rotary pedestal or the bottom surface of the impeller and the bottom surface of the pump chamber, and thrombus formation easily occurs.

The present invention has been made to solve the above problems. That is, an object of the present invention is to arrange a rotary pedestal, which has a built-in magnet for driving by a magnet coupling system and has a plurality of blades, in a pump chamber without providing a seal portion, without causing hemolysis. It is to provide a blood pump that can be smoothly operated for a long period of time.

Another object of the present invention is to incorporate a magnet for driving by a magnet coupling system and to promote the flow of blood from the back surface to the surface of a rotary pedestal having a plurality of blades. It is an object of the present invention to provide a blood pump that can be smoothly operated for a long period of time while minimizing thrombus formation on the back surface of the rotary pedestal, which was a problem in the technology.

[0013]

According to a first aspect of the present invention for attaining the above object, a plurality of blades are provided upright on an upper surface of a rotary base, and the rotary base is rotated by rotation of an external magnetic body. An impeller containing a magnet that allows the pedestal to rotate is disposed in the pump chamber, and the lower part of the rotary shaft of the rotary pedestal is supported by the lower support member in a line contact state or at least three point contact states in the pump chamber. The blood pump is characterized in that the upper part of the rotary shaft is supported by an upper support member in a line contact state or a point contact state.

According to a second aspect of the present invention, the rotary shaft is
The blood pump according to claim 1, wherein the blood pump has a through hole for circulating blood on the bottom surface of the rotary pedestal to the upper surface side of the rotary pedestal.

[0015]

According to the present invention, since the rotary shaft that allows the rotary pedestal to rotate does not penetrate outside the pump chamber, the rotary shaft does not have a seal portion. Therefore, the blood pump of the present invention has no leakage of blood to the outside of the pump chamber. Also,
Since it is not necessary to ensure the smoothness of rotation of the rotating shaft with a bearing or the like with respect to the fixed part, the rotating shaft due to the infiltration of blood into the bearing and the coagulation of the blood, such as when using a bearing. There is no overload phenomenon.

In this blood pump, the lower portion of the rotary shaft of the rotary pedestal is supported by the lower support member in a line contact state or at least three point contact states, and the upper portion of the rotary shaft is in a line contact state or a point contact state. Since it is supported by the upper support, the occurrence of hemolysis due to heat generation of the seal portion during high speed rotation of the rotary pedestal, which is a problem in the conventional sealing technology, can be suppressed to a low level.

With respect to the method of supporting the upper and lower sides of the rotary shaft, it is more stable to support the rotary shaft when the contact diameter of the lower support part of the rotary shaft is larger than that of the upper support part of the rotary shaft. This is because the rotational force is transmitted by the magnetic coupling between the magnetic substance outside the pump chamber and the magnetic substance inside the pump chamber, so that the rotary pedestal is always pulled downward by the magnetic substance outside the pump chamber, Therefore, a larger contact pressure is applied to the lower part of the rotary contact part on the lower part of the rotary shaft than to the rotary contact part on the upper part of the rotary shaft. Therefore, although it is possible to support both the upper part and the lower part of the rotary shaft by point contact, it is preferable that the rotary contact part is a line contact in consideration of stability during pump operation. More specifically, it is more preferable that the diameter of the contact portion at the lower portion of the rotating shaft is 1.5 times or more the diameter of the contact portion at the upper portion of the rotating shaft.

As a method for realizing the line contact support, the end of the rotary shaft of the rotary pedestal is formed into a spherical shape or a conical shape, and this is brought into contact with a ring having a circular cross section, or the rotary shaft of the rotary shaft is similarly contacted. A suitable method is one in which the ends are spherical or conical, and these are arranged in a circular shape at equal angles, and the ends are supported by three or more pins each having a spherical shape.

Regarding the clearance between the upper and lower contact parts of the rotary shaft, when the blood pump is vibrated in the vertical direction of the rotary shaft of the impeller, the backlash of the impeller does not occur, and the blood pump casing is Most suitably, it is adjusted so that the impeller smoothly rotates when held by hand and rotated in a plane perpendicular to the rotation axis of the impeller. As described above, when the pump is stopped and at a relatively low speed of 1,000 rpm or less, the impeller is pulled to the lower part of the rotating shaft by the magnetic coupling force with the magnetic substance outside the pump chamber. As the rotation speed increases, the pressure on the lower part (back surface) of the impeller decreases and the pressure difference with the upper part (front surface) of the impeller increases, so the axial pressure applied to the lower contact part of the rotating shaft is reduced. Axial pressure is also applied to the contact portion above the rotary shaft. In order to maintain stable rotational movement of the pump in response to changes in pressure applied to the support contact portions at the upper and lower portions of the rotary shaft due to changes in the rotational speed during such pump operation, the above-mentioned clearance is required. Adjustment is most suitable.

As for the materials of the supporting contact portions above and below the rotary shaft, various materials can be combined,
Surface-hardened materials such as stainless steel, ceramic or ceramic coating, hard chrome plating, nickel plating, graphite moldings, moldings made by mixing graphite and various resins, fluorinated ethylene, polyimide,
Combinations with polyetherketone (PEEK), polyethersulfone (PES), etc. are preferably used.

If a through hole is provided in the rotary shaft of the impeller for allowing blood on the lower surface of the rotary pedestal to flow back to the upper surface of the rotary pedestal, blood stays on the lower surface of the rotary pedestal during operation of the blood pump. Can be prevented. That is, during operation of the blood pump, the blood on the lower surface side of the rotary pedestal escapes from the lower surface side of the rotary pedestal to the upper surface side through the through hole, and there is no blood retention on the lower surface side of the rotary pedestal.

With this configuration, this blood pump has
Hemolysis during the operation of the blood pump can be suppressed to a low level, and since no seal portion is provided, smooth operation for a long period of time can be realized. By providing a through hole in the rotary shaft, blood retention is prevented and thrombus growth is eliminated, which also realizes smooth operation for a longer period of time.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. It is needless to say that the present invention is not limited to this embodiment, and design changes can be appropriately made within the scope of the gist of the present invention.

(Embodiment 1) FIG. 1 is a sectional view showing a blood pump according to an embodiment of the present invention.

As shown in FIG. 1, the blood pump 1 is
An impeller 3 is provided in the pump chamber 2.

The impeller 3 has a rotary pedestal 5 having an upper surface 4 which is a conical surface which is a gently inclined surface, and a plurality of impellers 6 which are erected radially on the upper surface of the rotary pedestal 5. A magnet plate 7 is annularly arranged in the rotary base 5 in a plane parallel to the bottom surface of the rotary base 5 about the rotation axis. The central portion of the upper surface of the rotary pedestal 5 has a gentle curved surface that projects upward from the conical surface, and its top is formed in a hemispherical shape. This hemispherical top is the hemisphere top 8
Called. Further, on the bottom surface of the rotary pedestal 5, an annular flat surface portion 9 and a recessed portion 10 which is surrounded by the flat surface portion 9 and is recessed in an inverted truncated cone shape, and a lower portion which protrudes in a hemispherical shape at the center portion of the recessed portion 10. A hemispherical portion 11 is formed. From the lower hemisphere portion 11 to the hemisphere top portion 8, openings 13a, 13b of through holes 12 penetrating from the bottom surface side of the rotary pedestal 5 to the upper surface side of the rotary pedestal 5.
Are open.

As shown in FIG. 1, the blood pump 1 is provided with a blood introducing tube 14 communicating with the inside of the pump chamber 2 on the upper surface side thereof, and on the peripheral side surface of the pump chamber 2, from the inside of the pump chamber 2 to the outside. A blood discharge pipe 15 for discharging blood is provided.

The inside of the pump chamber 2 has a circumferential inner surface 16, a bottom surface 17, and a conical inner surface 18 formed continuously from the circumferential inner surface 16 to form a cylindrical inner space having a low height as a whole. The inner space has a shape in which a conical inner space formed on the cylindrical inner space is combined. The blood introducing tube 14 is provided so as to open at the top of the conical internal space, and the blood discharging tube 15 is provided so as to open at the peripheral side surface of the cylindrical internal space.

On the bottom surface of the pump chamber 2, an annular first holding member having a diameter smaller than that of the lower hemispherical portion 11 is arranged so that its center is located on the center line thereof. 19 is supported by, for example, four inclined support members 20, and the diameter of the hemisphere is set so that the center is located on the center line of the pump chamber 2 near the opening of the blood introducing tube 14 in the conical inner space. An annular second holding member 21 having a circular cross section, which is designed to be smaller than the diameter of the top portion 8, is suspended by, for example, four inclined suspension members 22.

In the impeller 3 having the above structure, the lower hemisphere portion 11 is supported by the first holding member 19 in a line contact state, and the hemisphere top portion 8 is brought into a line contact state by the second holding member 21. And is supported in the pump chamber 2 so as to be freely rotatable.

In the blood pump shown in FIG. 1, the first holding member 19 corresponds to the lower support member of the present invention, the lower hemisphere portion corresponds to the lower part of the rotating shaft, and the second holding member 21 is the same. Corresponds to the upper support member in the invention,
The hemisphere top portion 8 corresponds to the upper part of the rotation axis.

The line contact radius between the lower hemisphere portion 11 and the first holding member 19 is set to 1.7 times the line contact radius between the hemisphere upper portion 8 and the second holding member 21.

In the blood pump 1 having the above construction, a pipe for sending blood from the human body is connected to the blood introduction pipe 14, and a pipe for returning blood to the human body is connected to the blood discharge pipe 15 through, for example, an artificial lung. Is connected, and the rotary pedestal 5 is rotated at a high speed by a magnetic coupling system by a driving device provided outside the blood pump 1, and the impeller 6
The blood is introduced into the pump chamber 2 from the blood introducing pipe 14 by the action of the centrifugal force due to the rotation of the blood, and the blood is discharged from the pump chamber 2 to the outside through the blood discharging pipe 15.

In this case, the rotary pedestal 5 rotates at a high speed with the vertical portion extending from the hemispherical top 8 to the lower hemisphere 11 as the axis of rotation. The blood introduced into the pump chamber 2 also flows between the bottom surface of the rotary pedestal 5 and the bottom surface of the pump chamber 2, but since the lower hemisphere portion 11 has the opening 13b of the through hole 12, Blood below the bottom surface of the rotary pedestal 5 flows into the through hole 12 through the opening 13b and flows out to the upper surface side of the rotary pedestal 5 through the opening 13a provided at the hemispherical top 8. That is, by providing the through hole 12, the blood in the pump chamber 2 circulates in the pump chamber 2 by flowing from the bottom surface side to the upper surface side of the rotary pedestal 5. Therefore, as is often seen in the conventional blood pump 1, blood does not stay between the bottom surface of the rotary pedestal 5 and the bottom surface inside the pump chamber 2. Since there is no blood retention, the blood pump 1 does not cause thrombus.

The lower hemisphere portion 11 is in line contact with the annular first holding member 19, and the hemisphere top portion 8 is in the annular second holding member 2.
Since it is in line contact with 1, even if the rotation axis from the lower hemisphere portion 11 to the hemisphere top portion 8 rotates at high speed, the generation of frictional heat due to the rotation is suppressed and the occurrence of the hemolysis phenomenon is suppressed. It

In this blood pump 1, since there is no rotary shaft penetrating from the inside of the pump chamber 2 to the outside unlike the conventional device, it is not necessary to provide a seal portion, and blood leaks from the pump chamber 2 to the outside. It doesn't exist at all.

Therefore, as described above, thrombus and hemolysis are suppressed, and there is no leakage of blood.
The blood pump 1 can be smoothly operated for a long period of time without being overloaded.

Animal experiments were carried out in order to confirm that the blood pump shown in FIG. 1 can be safely operated for a long period of time.

<Animal experiment> In order to bypass the left and right ventricles of a calf weighing 80 kg, the blood pump 2 shown in FIG.
By connecting the two, the bypass flow rate is 3 liters /
Maintained in minutes. Two weeks after the start of bypass, the centrifugal pumps on the left and right were replaced with two new centrifugal pumps, and continuous operation was performed for another two weeks.

Through this animal experiment, it was possible to confirm the durability for 2 weeks and the presence or absence of hemolysis and thrombus during the centrifugation for 4 centrifugal pumps, 2 on each of the left and right sides.

All four pumps showed stable discharge performance for 2 weeks. During the period of this experiment, the amount of free hemoglobin in the blood of calves was always normal (20 mg / dl or less).
Maintained in. In addition, after the experiment was completed, the four centrifugal pumps were disassembled, and the liquid in contact with the pump was visually observed.
No significant thrombus formation was observed, which is considered to be a problem in clinical use.

(Embodiment 2) FIG. 5 is a sectional view showing a blood pump according to another embodiment of the present invention.

The structure of the blood pump shown in FIG. 5 is basically the same as the structure of the blood pump shown in FIG. 1, but the blood pump 1A shown in FIG. 5 is different from the blood pump 1 shown in FIG. Is as follows:

That is, the difference between the blood pump 1A shown in FIG. 5 and the blood pump 1 shown in FIG.
An inverted frustoconical shaft base 11A protruding from the bottom is provided at the center of the recess 10 on the bottom of A.
The shaft base 11A is supported by the first holding member 19 so that the conical peripheral surface in 1A makes line contact with the first holding member 19,
The portion corresponding to the hemisphere top portion 8 of the blood pump 1 in FIG. 1 is not a complete hemisphere but a sphere top portion 8A forming a part of a spherical surface having a small radius, and the second holding member 21A has an annular shape as shown in FIG. It has a lower surface 21a which is not present and is a concave spherical surface having a radius larger than the radius of the ball top portion 8A, and is suspended by an inclined suspension member 22. The ball top portion 8A of the rotary pedestal 5A is suspended on the lower surface of the second holding member 21A. Is in point contact with each other, and a through hole 12A that opens at a plurality of points is provided on the peripheral surface of the spherical base 8A that is slightly lower than the top of the truncated cone and that is open to the truncated cone surface of the shaft base 11A. That is.

In the blood pump 1A shown in FIG. 5, the same parts as those in the blood pump 1 shown in FIG. 1 are denoted by the same reference numerals as in FIG.

The rotary base 5A has its shaft base 11A mounted on the first holding member 19 in line contact therewith, and also has a second base.
The holding member 21A is arranged in the pump chamber 2 so as to hold the ball crest 8A in a point contact state.

In the blood pump shown in FIG. 5, the first holding member 19 corresponds to the lower support member of the present invention, the shaft base 11A corresponds to the lower part of the rotary shaft, and the second holding member 21A corresponds to the present invention. And the ball crest portion 8A corresponds to the upper portion of the rotating shaft.

The blood pump 1A shown in FIG. 5 also exhibits basically the same operational effects as the blood pump 1 shown in FIG. However, the blood existing between the bottom surface 9 of the rotary pedestal 5A and the bottom surface 17 of the pump chamber 2 flows through the through hole 12A and is opened from a plurality of openings slightly lower than the ball crest 8A to the upper surface of the rotary pedestal 5A. Flow to. Therefore, the blood retention phenomenon disappears and the occurrence of the thrombosis phenomenon is suppressed. Even if the rotary pedestal 5A rotates at high speed, the ball crest 8A does not have the second holding member
Since the shaft base portion 11A is in point contact with 1A and the shaft base portion 11A is in line contact with the first holding member 19, since shear force is not applied to blood and frictional heat is not generated, the hemolysis phenomenon is suppressed. It In the blood pump 1A shown in FIG. 5, the rotary shaft of the rotary base 5A is not penetrated to the outside of the pump chamber 2,
Since there is no seal portion, the hemolysis phenomenon is suppressed also in this respect.

Therefore, the blood pump 1A shown in FIG. 5 can also be smoothly operated for a long period of time.

(Embodiment 3) FIG. 6 is a sectional view showing a blood pump according to another embodiment of the present invention.

The structure of the blood pump shown in FIG. 6 is basically the same as the structure of the blood pump shown in FIG. 1, but the blood pump 1B shown in FIG. 6 is different from the blood pump 1 shown in FIG. Is as follows:

That is, the blood pump 1B shown in FIG. 6 differs from the blood pump shown in FIG. 1 in that there is no first holding member 19 and first support member 20 in the blood pump shown in FIG. Centering on the center of the bottom surface 17,
Also, four of which the upper part is formed in a spherical shape are erected at four imaginary intersections where a circle having a diameter smaller than the diameter of the lower hemisphere portion 11 and an imaginary cross character passing through the center intersect. The column 23 is erected on the bottom surface 17 of the pump chamber 2, and the lower hemisphere portion 11 of the rotary pedestal 5 is supported by the upper portions of the four columns 23.

The impeller 3 having the above structure has a lower hemispherical portion 11 thereof.
Is supported in the point contact state on the upper portions of the four columns 23, and the hemispherical top portion 8 is supported in the line contact state by the second holding member 21, so that the hemispherical top portion 8 is rotatably mounted in the pump chamber 2. It

In the blood pump 1B shown in FIG. 6, the column 23 corresponds to the lower support member of the present invention,
The lower hemisphere portion 11 corresponds to the lower portion of the rotation shaft, the second holding member 21 corresponds to the upper support member in the present invention, and the hemisphere top portion 8 corresponds to the upper portion of the rotation shaft.

In the blood pump 1B shown in FIG. 6, the same parts as those in the blood pump 1 shown in FIG. 1 are denoted by the same reference numerals as in FIG.

The blood pump 1B shown in FIG. 6 also has basically the same operational effects as the blood pump 1 shown in FIG.

However, the bottom surface 9 of the rotary base 5 and the pump chamber 2
The blood existing between the bottom surface 17 and the bottom surface 17 flows through the through hole 12 and flows to the upper surface 4 of the rotary pedestal 5 through the opening 13a provided in the hemispherical top 8. Therefore, the blood retention phenomenon disappears and the occurrence of the thrombosis phenomenon is suppressed. Rotating base 5
Does not give a shearing force to the blood even when the hemisphere top portion 8 makes point contact with the second holding member 21 and the lower hemisphere portion 11 makes point contact with the support column 23 even when the object rotates at high speed. Since no heat is generated, the hemolysis phenomenon is suppressed. The blood pump 1B shown in FIG. 6 does not have the rotary shaft of the rotary pedestal 5 penetrating to the outside of the pump chamber 2, so there is no seal portion and the hemolysis phenomenon is suppressed also in this respect.

Therefore, blood pump 1B shown in FIG. 6 can also perform smooth operation for a long period of time.

(Embodiment 4) FIG. 7 is a sectional view showing a blood pump according to another embodiment of the present invention.

The structure of the blood pump shown in FIG. 7 is basically the same as the structure of the blood pump shown in FIG. 1, but the blood pump 1C shown in FIG. 7 is different from the blood pump 1 shown in FIG. Is as follows:

That is, the difference between the blood pump 1C shown in FIG. 7 and the blood pump 1 shown in FIG.
Instead of forming the center of the upper surface of the hemispherical top 8, the center of the upper surface of the rotating pedestal 5 is formed in a recessed portion 24 that is recessed in an inverted frustoconical shape. From the second holding member 21B and the second support member 22 shown in FIG. 7, instead of the second holding member 21 and the second support member 22 shown in FIG. Member 22B is used.

The second support member 22B shown in FIG. 7 is a tubular body supported by the inner wall of the opening of the blood introducing tube 14 in the pump chamber 2 and arranged with the axis of the blood introducing tube 14 as the center line. Is. The second holding member 21B is a hemisphere having a diameter larger than the diameter of the recessed portion 24 formed at the lower end portion of the tubular body that is the second support member 22B. An opening 21b continuous with the inner tube of the tubular body is opened at the lowermost part of the hemisphere, and a plurality of long holes 22b continuous with the inner tube are opened on the peripheral side surface of the tubular body. ing.

In the blood pump 1C shown in FIG. 7, in the impeller 3, the lower hemisphere portion 11 of the impeller 3 is the first holding member 1.
9 is supported in a point contact state, and the hemisphere is inserted into the concave portion 24 in a line contact state, so that the hemisphere is rotatably mounted in the pump chamber 2.

In the blood pump 1C shown in FIG. 7, the first holding member 19 corresponds to the lower support member of the present invention, the lower hemispherical portion 11 corresponds to the lower portion of the rotary shaft, and the lower end portion of the tubular body. The formed hemisphere corresponds to the upper support member in this invention, and the recessed portion 24 corresponds to the upper part of the rotation shaft.

In blood pump 1C shown in FIG. 7, the same parts as those in blood pump 1 shown in FIG. 1 are denoted by the same reference numerals as in FIG.

The blood pump 1C shown in FIG. 7 also has basically the same effect as the blood pump 1 shown in FIG.

However, the bottom surface 9 of the rotary base 5 and the pump chamber 2
Existing between the bottom surface 17 and the bottom surface 17 of the lower hemisphere 11 flows into the through hole 12 from the opening 13b, and the blood flowing into the through hole 12 opens from the opening 13a of the recess 24 into the opening of the hemisphere. 21b, opening 2 in the hemisphere
The blood flowing into 1b flows out to the upper surface of the rotary pedestal 5 through the long holes 22b provided on the peripheral side surface of the tubular body. Therefore, the blood retention phenomenon existing between the bottom surface 9 of the rotary pedestal 5 and the bottom surface 17 of the pump chamber 2 is eliminated, and the occurrence of the thrombosis phenomenon is suppressed. Even if the rotary pedestal 5 rotates at a high speed, since the concave portion 24 and the hemisphere are in line contact with each other and the lower hemisphere and the first holding member are in line contact with each other, the shearing force is not applied to blood. Moreover, since the frictional heat is not generated, the hemolysis phenomenon is suppressed. In the blood pump 1C shown in FIG. 7, since the rotary shaft of the rotary pedestal 5 is not penetrated to the outside of the pump chamber 2,
Since there is no seal portion, the hemolysis phenomenon is suppressed also in this respect.

Therefore, the blood pump 1C shown in FIG. 7 can also be smoothly operated for a long period of time.

(Embodiment 5) FIG. 8 is a sectional view showing a blood pump according to another embodiment of the present invention.

The structure of the blood pump shown in FIG. 8 is basically the same as the structure of the blood pump shown in FIG. 7, but the blood pump 1D shown in FIG. 8 is different from the blood pump 1 shown in FIG. Is as follows:

That is, the blood pump 1D shown in FIG. 8 is different from the blood pump 1 shown in FIG.
Instead of forming the center of the upper surface of the hemispherical top 8, the center of the upper surface of the rotating pedestal 5 is formed in a recessed portion 24 that is recessed in an inverted frustoconical shape. From the second holding member 21 and the second support member 22 shown in FIG. 1, a second holding member 21C and a second support member 21C shown in FIG. 8 are formed instead of the second holding member 21 and the second support member 22 shown in FIG. Member 22C is used.

The second support member 22C shown in FIG. 8 is supported by the inner wall of the opening in the pump chamber 2 of the blood introducing tube 14 and is arranged so as to be aligned with the axis X of the blood introducing tube 14. It is the body 22d. 2nd holding member 21C
Is a spherical body 21c having a diameter larger than the diameter of the concave portion 24, which is formed at the lower end of the rod-shaped body 22d that is the second support member 22C. At the lowermost part of the spherical body 21c, an opening 21d having the same size as the opening 13a of the concave portion 24 is opened, and the opening 21d is a plurality of openings that are opened horizontally in the spherical body 21c. Communicating with the opening 21e.

In the blood pump 1D shown in FIG. 8, the lower hemisphere portion 11 of the impeller 3 is the first holding member 1.
9 is supported in a point contact state, and the spherical body 21c is inserted into the concave portion 24 in a line contact state,
It is mounted rotatably in the pump chamber 2.

In the blood pump 1D shown in FIG. 8, the first holding member 19 corresponds to the lower support member of the present invention, the lower hemispherical portion 11 corresponds to the lower portion of the rotating shaft, and the lower end portion of the rod-shaped body 22d. The spherical body 21c formed in the above corresponds to the upper support member in the present invention, and the recessed portion 24 corresponds to the upper portion of the rotating shaft.

In blood pump 1D shown in FIG. 8, the same parts as those in blood pump 1 shown in FIG. 1 are denoted by the same reference numerals as in FIG.

The blood pump 1D shown in FIG. 8 also has basically the same operational effects as the blood pump 1 shown in FIG.

However, the bottom surface 9 of the rotary base 5 and the pump chamber 2
Existing between the bottom surface 17 and the bottom surface 17 of the lower hemisphere portion 11 flows into the through hole 12 through the opening portion 13b, and the blood that flows into the through hole 12 extends through the opening portion 13a of the recessed portion 24 into the sphere 21c.
The blood that has flowed into the opening 21d of the sphere 21c and has flowed into the opening 21d of the sphere 21c passes through the inside of the sphere 21c and flows out from the opening 21e to the upper surface of the rotary pedestal 5. Therefore, the bottom surface 9 of the rotary pedestal 5 and the bottom surface 17 of the pump chamber 2 are
The retention phenomenon of blood existing between and is eliminated, and the occurrence of thrombosis is suppressed. Even if the rotation base 5 rotates at high speed,
Since the concave portion 24 and the sphere 21c are in line contact with each other and the lower hemisphere portion 11 and the first holding member 19 are in line contact with each other, it is possible to generate frictional heat without applying shearing force to blood. Since it does not exist, the hemolysis phenomenon is suppressed. In the blood pump 1D shown in FIG. 8, the rotary shaft of the rotary base 5 is not penetrated to the outside of the pump chamber 2, so there is no seal portion and the hemolysis phenomenon is suppressed also in this respect.

Therefore, the blood pump 1D shown in FIG. 8 can also be smoothly operated for a long period of time.

(Modifications) Some embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and the design may be appropriately changed within the scope of the gist of the present invention. be able to.

In the present invention, the lower part of the rotary shaft of the rotary pedestal is supported by the lower support member in the line contact state or the point contact state of at least three points, and the upper part of the rotary shaft is in the line contact state or the point contact state. As long as it can be supported by the upper support member, the shape of the upper and lower portions of the rotary shaft may be any shape, and the shape of the lower support member and the upper support member may be any shape. good.

In the present invention, it is sufficient that the bottom surface of the rotary pedestal has a through hole for circulating blood to the upper surface side of the rotary pedestal. Therefore, the through hole needs to be provided in the rotary shaft of the rotary pedestal. Alternatively, for example, at least one through hole may be formed between the impellers of the rotary pedestal so as to penetrate from the bottom surface to the upper surface of the rotary pedestal.

[0082]

In the blood pump of the present invention described in detail above, since the rotary shaft of the rotary pedestal is not penetrated to the outside of the pump chamber, the rotary shaft and the pump chamber penetrated to the outside of the pump chamber as in the conventional device. Since the seal part for improving the sealability of the device is not necessary and the seal part does not exist, there is no leakage of blood to the outside of the pump chamber at the seal part as in the conventional device, and the leaked blood coagulates. It does not hinder the rotation of the rotary shaft.

In the blood pump of the present invention, since the upper and lower parts of the rotary shaft in the rotary base are held by line contact or point contact with the holding members holding the respective parts, the shearing caused by the high speed rotation of the rotary shaft is suppressed. Hemolysis due to force and hemolysis due to frictional heat due to high speed rotation are suppressed.

Therefore, since the blood pump of the present invention does not leak blood and the hemolysis phenomenon is suppressed, it can withstand long-term operation. Moreover, by further providing the through hole for circulating the blood on the bottom surface of the rotary pedestal to the upper surface side of the rotary pedestal, the blood can be prevented from staying and the pump can have a longer life.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an example of a conventional blood pump.

FIG. 3 is a cross-sectional view showing an example of a conventional blood pump.

FIG. 4 is a cross-sectional view showing an example of a conventional blood pump.

FIG. 5 is a sectional view showing another embodiment of the present invention.

FIG. 6 is a sectional view showing another embodiment of the present invention.

FIG. 7 is a sectional view showing another embodiment of the present invention.

FIG. 8 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1, 1A, 1B, 1C, 1D Blood pump 2 Pump chamber 3 Impeller 4 Upper surface 5, 5A Rotating pedestal 6 Impeller 7 Magnet plate 8 Hemisphere top 8A Ball top 9 Flat surface 10 Recess 11 Lower hemisphere 11A Shaft base 12, 12A Through holes 13a, 13b Openings 14 Blood introduction tube 15 Blood discharge tube 16 Circumferential inner surface 17 Bottom surface 18 Conical inner surface 19 First holding member 20 First support members 21, 21A, 21B, 21C Second holding member 21b Opening 21c Sphere 21d, 21e Opening part 22 Inclined suspension member 22B, 22C 2nd support member 22b Long hole 22d Rod-like body 23 Strut 24 Recessed part

Claims (2)

[Claims] 1. An impeller in which a plurality of blades are provided upright on the upper surface of a rotary pedestal, and a magnet which allows the rotary pedestal to rotate by the rotation of an external magnetic body is arranged in the pump chamber. The lower part of the rotary shaft of the rotary pedestal is supported by the lower support member in the line contact state or at least three point contact states, and the upper part of the rotary shaft is supported by the upper support member in the line contact state or the point contact state. A blood pump characterized by being supported. 2. The blood pump according to claim 1, wherein the rotary shaft has a through hole that allows blood on the bottom surface of the rotary pedestal to flow back to the upper surface side of the rotary pedestal.