JPH11244377A - Centrifugal blood pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable decreasing the consumption of electricity. SOLUTION: The centrifugal liquid pump 1 consists of housing 20, impeller 21 that turns round inside the housing 20, rotor 31 that consists of magnet 33 to draw magnetic body 25 of the impeller 21, motor 34 that makes the rotor 31 round and an electromagnet to draw magnetic part 28 of the impeller 21. The housing 20 consists of port 22 into which bloods can be flowed and that is projected vertically from the center of the upper surface, part 52 into which bloods are flowed and of which inner diameter should be less than 9 mm while it is connected with the opening 51 for bloods that is shaped by the opening end of the port 22, blood chamber 24 and a port from which bloods are flooded. The electromagnet is cased in the housing 20 as the distance between it and the inside wall (inside wall of the pipe 20b) that exists next to the part 52 and shapes it should be less than 1.5 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal blood pump device for transporting blood, and more particularly to a centrifugal blood pump device applicable to an implantable living body.

[0002]

2. Description of the Related Art Recently, a centrifugal blood pump has been increasingly used for extracorporeal blood circulation in a heart-lung machine. As a centrifugal pump, one that completely eliminates physical communication between the outside and the blood chamber in the pump and prevents invasion of bacteria, etc., so that the drive torque from an external motor is transmitted using magnetic coupling. Is used. And
Such a centrifugal blood pump has a housing having a blood inflow port and a blood outflow port, and an impeller that rotates in the housing and feeds blood by centrifugal force during rotation. The impeller is provided with a magnetic body (permanent magnet) inside, and is rotated by a rotor having a magnet for attracting the magnetic body of the impeller and a rotation torque generating mechanism having a motor for rotating the rotor. The inside diameter of the blood inflow port of such a blood pump is 10 mm in accordance with the inside diameter of the blood removal cannula.

[0003]

The centrifugal blood pump as described above has been studied for implantation into a living body.
It is necessary to make the duration of the internal battery as long as possible, and for this purpose, it is necessary to reduce the power consumption of the blood pump device as much as possible.

[0004] In the current magnetic levitation centrifugal pump, the magnetic support of the impeller requires several times the energy of the pump work. Therefore, reduction of the energy required for the magnetic support is an important subject to be studied. As a means for reducing the energy required for magnetic support, a method of increasing the height of the electromagnet core and increasing the number of turns of the coil can be considered. However, this method has a problem that the size of the electromagnet part is increased, and the size of the blood pump is increased.

[0005] Another method of reducing the number of windings is to increase the number of windings of the electromagnet by providing a structure in which a blood inflow port penetrates the inside of the rotary drive motor. However, in this method, the bearing provided in the rotary drive motor becomes large,
There is a problem that the energy required for driving the motor increases due to the friction loss in the bearing.

SUMMARY OF THE INVENTION It is an object of the present invention to increase the outer diameter of the electromagnet portion, increase the power consumption of the rotary drive motor, and maintain the strength of the blood inflow port made of a polymer material. An object of the present invention is to provide a centrifugal blood pump device capable of reducing energy required for magnetic support and reducing power consumption as a pump device.

[0007]

An object of the present invention is to provide an impeller which includes a housing, a magnetic material and a magnetic member therein, and which rotates in the housing and feeds blood by centrifugal force during rotation. A centrifugal blood pump unit, a rotor including a magnet for attracting a magnetic material of the impeller of the centrifugal blood pump unit, an impeller rotation torque generating unit including a motor for rotating the rotor, and a magnetic member of the impeller A centrifugal blood pump device that includes an impeller position control unit including an electromagnet for sucking air, wherein the impeller rotates in a non-contact state with respect to the housing, wherein the housing is near a center of an upper surface of the housing. A blood inflow port provided so as to protrude substantially vertically, and a blood inflow port formed by an open end of the blood inflow port and continuous with a blood inflow port formed by the open end of the blood inflow port A blood inlet having an inner diameter of 9 mm or less, a blood chamber communicating with the blood inlet, and a blood outlet port communicating with the blood chamber, wherein the electromagnet is adjacent to the blood inlet and the blood The centrifugal blood pump device is housed in the housing so that the distance from the inner wall forming the inflow portion is 1.5 mm or more.

[0008] The outer diameter of the maximum outer diameter portion in the blood inflow portion forming portion and in the vicinity of the electromagnet is 15 mm.
mm or less. Further, the outer diameter of the open end of the blood inflow port is preferably 11 mm or less. Further, the blood inflow portion is formed of a cylindrical body, and the outer diameter of a maximum portion of the cylindrical body is 15 m.
m or less and an inner diameter of 6 mm to 9 mm. Further, it is preferable that the tubular body forming the blood inflow portion is formed of any of polycarbonate, polymethyl acrylate, and ultra-high-molecular-weight polyethylene. Further, the inner diameter of the blood inflow section is 6 mm to 8 mm.
It is preferred that In addition, the blood outflow port,
Preferably, it is provided so as to protrude tangentially from the side surface of the housing. Further, it is preferable that the impeller position control section includes a plurality of electromagnets radially and substantially equiangularly arranged with respect to the blood inflow section, and the electromagnet includes an iron core and a coil. Preferably, the impeller position control unit includes a position sensor for detecting a position of a magnetic member of the impeller.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A centrifugal liquid pump device according to the present invention will be described with reference to an embodiment applied to a blood pump. FIG.
1 is a front view of an embodiment of a centrifugal liquid pump device according to the present invention. FIG. 2 is a plan view of the main body of the centrifugal liquid pump device shown in FIG. FIG. 3 is a cross-sectional view of the centrifugal liquid pump device main body of FIG. 1 cut along an impeller portion. FIG. 4 is a sectional view taken along line AA of FIG. 2, and FIG.
The cut state is schematically shown by the bent broken line of FIG.

The centrifugal liquid pump device 1 of the present invention includes a housing 20, a magnetic body 25 and a magnetic member 28 therein, and rotates inside the housing 20 to feed blood by centrifugal force at the time of rotation. 31 having a centrifugal blood pump unit 2 having a magnet and a magnet 33 for attracting the magnetic body 25 of the impeller 21 of the centrifugal blood pump unit 2
And an impeller rotation torque generating unit 3 including a motor 34 for rotating the rotor 31, and a magnetic member 28 of the impeller 21.
This is a centrifugal blood pump device that includes an impeller position control unit 4 including an electromagnet 41 for sucking air, and rotates the impeller 21 in a non-contact state with respect to the housing 20.

Then, the housing 20 is connected to the housing 2
The blood inflow port 22 provided so as to protrude substantially vertically from the vicinity of the center of the upper surface of the blood inlet 0 and the blood inflow port 51 formed by the open end of the blood inflow port 22 and having an inner diameter of 9 mm or less. A blood chamber 24 communicating with the blood inlet section 52; and a blood outlet port 23 communicating with the blood chamber 24. The electromagnet 41 includes a blood inflow portion 52
Inner wall (cylindrical body 20b)
Is housed in the housing 20 so as to have a distance of 1.5 mm or more.

As shown in FIGS. 1 to 4, a centrifugal blood pump device main body 5 of this embodiment has a
Centrifugal blood pump unit 2 having a housing 20 having a housing 2 and a blood outflow port 23, and an impeller 21 which rotates in the housing 20 and sends blood by centrifugal force during rotation.
And an impeller rotational torque generator (non-control type magnetic bearing component) 3 for the impeller 21 and an impeller position controller (control type magnetic bearing component) 4 for the impeller 21.

The impeller 21 rotates while being held at a predetermined position in the housing 20 by the action of the uncontrolled magnetic bearing component and the controlled magnetic bearing component.

The housing 20 includes a housing body 20.
a, cylindrical body 20b forming blood inflow portion 52, lid member 2
0c, and all are formed of a non-magnetic material. The lower end of the cylindrical member 20b is fixed to the central opening of the housing 20a. The upper end of the cylindrical body 20b protrudes from the central opening of the lid member 20c, and forms a blood inflow port 22. For this reason, the housing 20 includes a blood inflow port 22 provided so as to protrude substantially vertically from near the center of the upper surface of the housing 20.

The cylindrical body 20b forms a blood inflow port 51 formed by the open end of the blood inflow port 22, and a blood inflow section 52 continuous with the blood inflow port and having an inner diameter of 9 mm or less. The housing 20a includes a blood chamber 24 that communicates with the blood inflow section 52 and a blood outflow port 23 that communicates with the blood chamber 24. Blood outflow port 23
Is provided so as to tangentially protrude from a side surface of the housing 20a formed in a substantially cylindrical shape.

The inner diameter of the cylindrical body 20b, in other words, the inner diameter of the blood inflow section 52 is 9 mm or less. Especially,
It is preferably from 6 to 9 mm, and more preferably from 6 to 8 mm. If it is 9 mm or less, a space where the winding of the coil of the electromagnet described later can be increased can be secured, and the pump efficiency hardly decreases. If it is 6 mm or more, a decrease in pump efficiency is small. Specifically, when a glycerin aqueous solution having a viscosity of 4 cP was used as a circulating fluid, and pump heads (pressure difference before and after the pump) were compared at several rotation speeds and flow rates, the inner diameter of the blood inflow portion was set to, for example, 6 mm. No decrease in the pump head was observed as compared with the 10 mm one. Also, the inner diameter of the blood inlet 51 is preferably 9 mm or less.

Further, the outer diameter of the cylindrical body (the maximum outer diameter of the blood inflow portion forming portion) is 15 mm or less, and the thickness of the cylindrical body is 1.5 to 3 mm. By setting the outer diameter of the cylindrical body to 15 mm or less in this way, it is possible to reliably secure a space in which the winding of the coil of the electromagnet described later can be increased. In addition, with such a thickness, sufficient strength is provided as an inner wall for forming the blood inflow portion 52.

The form of the housing 20, particularly the form of the cylindrical body, is not limited to that shown in FIG. 4, but may be, for example, one shown in FIG. In the embodiment shown in FIG. 5, the housing main body 2a has a central opening and a cylindrical cylindrical fixing portion 20d protruding above the opening end. For this reason, the blood inflow portion forming portion is constituted by the fixing portion 20d and the cylindrical body 20b. In this embodiment, the cylindrical body fixing portion 20d is a blood inflow portion forming portion and a maximum outer diameter portion in a portion close to the electromagnet (coil) side surface. The outer diameter of the cylindrical body fixing portion 20d is 15 mm or less, and the thickness of the fixing portion 20d is 1.5 to 3 mm. With such a thickness, sufficient strength is provided as an inner wall for forming the blood inflow portion 52. Also,
The thickness of the cylindrical body 20b can be made thinner than the embodiment shown in FIG. Specifically, the thickness of the cylindrical body 20b is
1.5 to 2 mm.

Examples of the material for forming the housing 20 include polycarbonate, acrylic resin (polyacrylate (for example, polymethyl methacrylate, polymethyl acrylate), polyacrylamide, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, etc.). Hard synthetic resins such as polyolefins (polyethylene, polypropylene, ethylene-propylene copolymer, ultra-high-molecular-weight polyethylene), styrene resins (polystyrene, MS resin (methacrylate-styrene copolymer), MBS resin (methacrylate-butylene-styrene copolymer)) In particular, polycarbonate, polymethyl acrylate, and ultra-high-molecular-weight polyethylene are preferable.

Blood chamber 24 formed in housing 20
Inside, a disk-shaped impeller 21 having a through hole in the center is housed. The impeller 21 has a donut plate-like member (lower shroud) 27 forming a lower surface, and a donut plate-like member (upper shroud) forming an upper surface and having an open center.
28 and a plurality (six) of vanes 18 formed between them.
Having. And between the lower shroud and the upper shroud, a plurality (six) of which are partitioned by adjacent vanes 18
Blood passage 26 is formed. The blood passage 26 communicates with the central opening of the impeller 21, starts at the central opening of the impeller 21, and extends curvedly to the outer peripheral edge. In other words, the vanes 18 are formed between the adjacent blood passages 26. In this embodiment, the blood passages 26 and the vanes 18 are provided at equal angular intervals and in substantially the same shape.

A plurality (specifically, six) of magnetic bodies 25 (permanent magnets and driven magnets) are embedded in the impeller 21. The embedded magnetic body 25 (permanent magnet) attracts the impeller 21 to a side opposite to the blood inflow port 22 by a permanent magnet 33 provided on a rotor 31 of the impeller rotating torque generating unit 3 described later, and also applies the rotating torque to the impeller. It is provided to enable transmission from the rotation torque generating unit. Further, by embedding a certain number of magnetic bodies 25 in this way, a magnetic coupling with the rotor 31 described later can be sufficiently ensured. The shape of the magnetic body 25 (permanent magnet) is preferably circular.

The impeller 21 has an upper shroud itself or a magnetic member 28 provided in the upper shroud. In this embodiment, the entire upper shroud is formed by the magnetic member 28. Magnetic member 28
Is provided for attracting the impeller 21 to the blood inflow port 22 side by the electromagnet 41 of the impeller position control unit described later. As the magnetic member 28, a magnetic stainless steel, nickel, soft iron member or the like is used.

A non-contact magnetic bearing is constituted by the impeller position control section 4 and the impeller rotational torque generating section 3,
When the impeller 21 is pulled from the opposite direction, the impeller 21 is stabilized at an appropriate position in the housing 20 where the impeller 21 does not contact the inner surface of the housing 20, and rotates inside the housing 20 in a non-contact state.

The impeller rotating torque generating section 3 includes a rotor 31 housed in the housing 20 and a motor 34 for rotating the rotor 31 (the internal structure is omitted). The rotor 31 includes a rotating plate 32 and a plurality of permanent magnets 33 provided on one surface (the surface on the blood pump side) of the rotating plate 32.
Consists of The center of the rotor 31 is fixed to the rotation shaft of the motor 34. The plurality of permanent magnets 33 are provided at equal angles so as to correspond to the arrangement form (number and arrangement position) of the permanent magnets 25 of the impeller 21.

The impeller rotating torque generating section 3 is not limited to the one having the rotor and the motor described above. For example, the impeller rotating torque generating section 3 may include a plurality of stator coils for attracting and rotating the permanent magnet 25 of the impeller 21. Good. Further, the impeller rotation torque generating section 3 is provided with a sensor 35 for detecting the number of rotations of the motor 34 or the rotor 31. Optical sensors,
Magnetic sensors can be used. Also, the rotation speed of the motor is
It may be detected from the back electromotive force between the motor coils.

The impeller position controller 4 includes a plurality of fixed electromagnets 41 for attracting the magnetic member 28 of the impeller.
And a position sensor 42 for detecting the position of the magnetic member 28 of the impeller. Specifically, the electromagnet 41 of the impeller position control unit 4 is arranged such that the distance between the electromagnet 41 and the inner wall (the inner wall of the cylindrical body 20b) that is adjacent to the blood inflow unit 52 and forms the blood inflow unit 52 is 5 mm or less. 20
(Internal space formed by the housing body 20a, the cylindrical body 20b, and the lid member 20c).

Also, in the blood pump device of this embodiment,
In the housing 20, a plurality (specifically, three) of electromagnets 41a, 41b, and 41c are provided radially and equiangularly (about 120 degrees) around the blood inflow portion 52. Also, a plurality of position sensors 42 are provided, and the position sensors 42a, 42b, and 42c are also at equal angles (about 120 °) such that the position sensors are located in the middle of the electromagnets with the blood inflow portion 52 as the center. ) Provided at intervals. Therefore, the electromagnet and the position sensor are arranged at intervals of 60 degrees. A potting agent is filled between the electromagnet and the sensor and the inner surface of the housing, and the electromagnet and the sensor are fixed.

In this embodiment, three electromagnets 41 are provided. The number of the electromagnets 41 may be three or more, for example, four. Three or more are provided, and these electromagnetic forces are
2 using the detection result of impeller 2
The force in the central axis (z-axis) direction can be balanced, and the moments about the x-axis and the y-axis orthogonal to the central axis (z-axis) can be made the same.

The electromagnet 41 includes an iron core 54 and a coil 55. Specifically, coils 55a and 55b each having a wire diameter of 0.5 mm are wound around bent portions at both ends of the U-shaped iron core 54, respectively. Then, the plurality of electromagnets 41a, 41
The coils b and 41c are arranged such that their coils 55a and 55b are located concentrically with respect to the blood inflow section 52. For this reason, the inner coil 55 b (on the blood inflow portion 52 side) of the electromagnet 41 approaches the blood inflow portion 52. The electromagnet is connected to the side surface of the inner coil 55b and the blood inflow portion 5.
The distance from the inner surface of the cylindrical body 20b forming the second member 2 is 5 mm or less. More preferably, it is 1.5 to 5 mm. If it is 5 mm or less, a sufficient storage space for the electromagnet can be secured. The distance between the side surface of the inner coil 55b of the electromagnet and the outer surface of the cylindrical body 20b is 1.5 mm or less.

As described above, the inner diameter of the blood inflow section 52 (the inner diameter of the cylindrical body 20b) is 9 mm or less, preferably 8 m
m or less, a coil (especially, the inner coil 55b) whose winding is further increased compared to the case of an inner diameter of 10mm can be accommodated, and the side surface of the inner coil 55b and the blood inflow can be accommodated. By setting the distance from the inner wall surface forming the portion 52 (the inner surface of the cylindrical body or the inner surface of the cylindrical body fixing portion) to 5 mm or less, there is no change in the outer diameter of the centrifugal pump. The attractive force of the electromagnet is proportional to the square of the number of turns of the coil and the square of the current. In this blood pump, a further increase in coils would be about a 10% increase in turns. When the number of turns increases by 10%, the current required to generate the same suction force is
1/1. Therefore, the input power to the coil can be reduced by about 10%.

The position sensor 42 detects the gap between the electromagnet 41 and the magnetic member 28, and this detection output is fed back to a control unit (not shown) for controlling the current or voltage applied to the coil of the electromagnet 41. Is done. Also, even if a radial force due to gravity or the like acts on the impeller 21,
Permanent magnet 25 of impeller 21 and permanent magnet 3 of rotor 31
3 and the shear force of the magnetic flux between the electromagnet 41 and the magnetic member 2
8, a shear force of magnetic flux acts between the impeller 21 and the impeller 21.
Is held in the center of the housing 20.

[0032]

The centrifugal blood pump device according to the present invention has a housing, a magnetic body and a magnetic member therein, and a centrifugal blood pump having an impeller that rotates in the housing and feeds blood by centrifugal force during rotation. A blood pump unit, a rotor having a magnet for attracting a magnetic body of the impeller of the centrifugal blood pump unit, an impeller rotating torque generating unit having a motor for rotating the rotor, and a magnetic member of the impeller being attracted. A centrifugal blood pump device that includes an impeller position control unit including an electromagnet for rotating the impeller in a non-contact state with respect to the housing,
The housing is continuous with a blood inflow port provided to protrude substantially vertically from the vicinity of the center of the upper surface of the housing, and a blood inflow port formed by an open end of the blood inflow port, and has an inner diameter of 9 mm or less. Blood inflow section,
A blood chamber communicating with the blood inlet; and a blood outlet port communicating with the blood chamber, wherein the electromagnet has a distance of 1.1 from an inner wall adjacent to the blood inlet and forming the blood inlet. It is housed in the housing so as to be 5 mm or more.

For this reason, without increasing the outer diameter of the electromagnet portion and without increasing the power consumption of the rotary drive motor,
In addition, reducing the energy required for magnetic support while maintaining the strength of the blood inflow port made of a polymer material,
The power consumption of the pump device can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of a centrifugal liquid pump device according to the present invention.

FIG. 2 is a plan view of a main body of the centrifugal liquid pump device shown in FIG. 1;

FIG. 3 is a sectional view of the centrifugal liquid pump device main body of FIG. 1 cut along an impeller part.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a sectional view of another embodiment of the centrifugal liquid pump device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Centrifugal blood pump device 2 Centrifugal blood pump unit 3 Impeller rotation torque generation unit 4 Impeller position control unit 5 Centrifugal blood pump device main unit 20 Housing 21 Impeller 22 Blood inflow port 23 Blood outflow port 24 Blood chamber 25 Magnetic material 28 Magnetic member 31 Rotor 34 Motor 41 Electromagnet 52 Blood inlet

Claims (8)

[Claims] 1. A centrifugal blood pump unit having a housing, a magnetic body and a magnetic member therein, and an impeller that rotates in the housing and feeds blood by centrifugal force during rotation. A rotor having a magnet for attracting a magnetic material of the impeller of a pump unit, an impeller rotation torque generating unit having a motor for rotating the rotor, and an impeller position control unit having an electromagnet for attracting a magnetic member of the impeller A centrifugal blood pump apparatus in which the impeller rotates in a non-contact state with respect to the housing, wherein the housing is provided so as to protrude substantially vertically from near the center of the upper surface of the housing. An inflow port, a blood inflow portion continuous with the blood inflow port formed by the open end of the blood inflow port, and having an inner diameter of 9 mm or less;
A blood chamber communicating with the blood inlet; and a blood outlet port communicating with the blood chamber, wherein the electromagnet has a distance of 1.1 from an inner wall adjacent to the blood inlet and forming the blood inlet. A centrifugal blood pump device which is housed in the housing so as to be 5 mm or more. 2. The centrifugal blood pump device according to claim 1, wherein an outer diameter of a maximum outer diameter portion in a portion which is a blood inflow portion forming portion and is close to the electromagnet is 15 mm or less. 3. The blood inflow section is formed of a cylindrical body, and the outer diameter of a maximum portion of the cylindrical body or the cylindrical body fixing portion is 15 mm or less, and the inner diameter is 6 mm or more. Or the centrifugal blood pump device according to 2. 4. The centrifugal blood pump device according to claim 3, wherein the tubular body forming the blood inflow portion is formed of a hard synthetic resin. 5. An inner diameter of the blood inflow section is 6 mm to 8 m.
The centrifugal blood pump device according to any one of claims 1 to 4, wherein m is m. 6. The centrifugal blood pump device according to claim 1, wherein the blood outflow port is provided so as to project tangentially from a side surface of the housing. 7. The impeller position control section includes a plurality of electromagnets radially and substantially equiangularly arranged with respect to the blood inflow section, and the electromagnet includes an iron core and a coil. 4. The centrifugal blood pump device according to 1. 8. The centrifugal blood pump device according to claim 1, wherein the impeller position control unit includes a position sensor for detecting a position of a magnetic member of the impeller.