CN213527132U

CN213527132U - Artificial heart blood pump adopting Halbach magnetic steel technology

Info

Publication number: CN213527132U
Application number: CN202020714066.8U
Authority: CN
Inventors: 李欣阳
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-04-30
Filing date: 2020-04-30
Publication date: 2021-06-25
Anticipated expiration: 2030-04-30

Abstract

In order to solve the problem that the blood pump with a magnetic suspension structure in the prior art is heavier, the utility model provides an artificial heart blood pump adopting a Halbach magnetic steel technology, which comprises a pump body and a rotor component positioned in the pump body; the pump body comprises a motor shell and a sealed cavity, a blood outlet is formed in the sealed cavity, the motor shell is located above the sealed cavity, and a blood inlet is connected above the motor shell; the motor casing is hollow structure, is provided with stator module in the cavity of motor casing, the rotor subassembly includes the impeller of pivot and pivot below connection, and wherein the impeller is located the sealed cavity, still be provided with rotor magnet steel in the pivot, wherein rotor magnet steel is corresponding with stator module. When the blood pump is actually applied, the volume of the motor is reduced, so that the volume of the blood pump is reduced, and the materials of parts such as a shell are reduced, so that the weight of the blood pump is reduced; simultaneously, the structure is simple, and the processing is convenient.

Description

Artificial heart blood pump adopting Halbach magnetic steel technology

Technical Field

The utility model relates to a device for assisting the flow of blood, in particular to an artificial heart blood pump adopting Halbach magnetic steel technology.

Background

In recent years, with the aging of the population of China and the change of living habits of people, the incidence of cardiovascular diseases is increased dramatically. Heart failure is a clinical syndrome of the development of various cardiovascular diseases to the advanced stage, and is the leading killer of cardiovascular diseases. Heart transplantation is the gold standard for the treatment of heart failure, but faces the problem of donor shortages. The number of heart transplantation operations in China is only about 300 per year, so that the death rate of NYHA IV grade heart failure patients reaches 35% in 6 months of waiting for donors, and if cardiogenic shock is combined, the death rate can reach 50% -70%. In addition, according to statistics, the number of heart failure patients in China is increased at the rate of 50 ten thousand new cases each year, so that the future application prospect of the artificial heart in the field of heart failure is very wide.

The artificial heart is the highest technology of science and technology content in cardiovascular medical appliances, belongs to a typical multidisciplinary cross-infiltration high-end product, integrates the technologies in multiple fields including mechanical design, fluid mechanics optimization, microelectronic circuits, automatic control, surgery and the like, and mainly comprises three parts: artificial blood vessels, hydrodynamic devices and system control parts. Among them, the fluid power device, i.e. the blood pump, is the most important because it determines the strength of the blood pumping ability of the artificial heart. The existing blood pump can be divided into an external pump and an internal pump according to the arrangement position according to the structure. For example, the electrohydraulic heart extracorporeal circulation pulsating blood pump disclosed in CN100509066C is placed outside the body, and through electrically controlling the pulsation frequency and the blood flow rate, the blood supply balance required in the human body is ensured.

In order to reduce the burden of a patient, a blood pump can be implanted into a body, and the patent of patent number CN200810226113.8 named as an implanted micro streamline axial flow blood pump is applied in 2008 by Qinghua university, and the patent technology discloses a blood pump capable of being implanted into the body, wherein the pump can provide larger blood flow, but the rotating speed of the blood pump is as high as about 8000 rpm, the damage to red blood cells in blood is extremely large, hemolysis is easy to generate, and meanwhile, thrombus and other problems are easy to generate on a supporting plate of an axial flow impeller.

In order to reduce the rotating speed, chinese patent CN103591028B also discloses an apical implanted centrifugal pump for treating heart failure, which adopts an upper and lower stator structure with a rotor assembly in between, and has a huge overall structure, for example, when the volume of the centrifugal pump manufactured by the technology of this patent is 80ml, the centrifugal pump weighs about 220 g; the diameter of the pump is about 53mm, and the height of the pump is about 56 mm; this increases the burden on the patient; therefore, in a limited space range, how to reduce the weight and the volume of the blood pump becomes a problem to be solved urgently by the technical personnel in the field.

SUMMERY OF THE UTILITY MODEL

In order to solve the heavier problem of magnetic suspension structure blood pump among the prior art, the utility model provides an adopt artificial heart blood pump of halbach magnet steel technique, its aim at alleviates the weight of blood pump, reduces the volume of pump, under the same rotational speed, the utility model discloses a blood pump has bigger flow, the lighter pump body.

The utility model provides a technical scheme that its technical problem adopted is: an artificial heart blood pump adopting Halbach magnetic steel technology comprises a pump body and a rotor assembly positioned in the pump body; the pump body comprises a motor shell and a sealed cavity, a blood outlet is formed in the sealed cavity, the motor shell is located above the sealed cavity, and a blood inlet is connected above the motor shell; the motor casing is hollow structure, is provided with stator module in the cavity of motor casing, the rotor subassembly includes the impeller of pivot and pivot below connection, and wherein the impeller is located the sealed cavity, still be provided with rotor magnet steel in the pivot, wherein rotor magnet steel is corresponding with stator module.

When the pump body is applied specifically, the pump body is of a shell structure, the upper part of the pump body is a blood inlet channel, the middle part of the pump body is a motor shell, and the lower part of the pump body is a sealed cavity, so that the pump body, the motor shell and the sealed cavity can be combined together by welding or other modes in the prior art, and the pump body is convenient to manufacture and assemble; the motor shell is of a hollow structure, and can contain a stator assembly, wherein the motor shell can also be formed by welding an upper shell and a lower shell; in the application, after the stator coil is electrified, the rotor is driven to rotate, blood enters through the blood inlet, the axial flow blades on the blood inlet channel pressurize the blood for the first time, then the blood flows to the seal cavity through the blood inlet channel, and the blood is pumped out from the blood outlet on the seal cavity after being pressurized for the second time through the rotation of the impeller in the seal cavity; the rotor is provided with rotor magnetic steel which is of a permanent magnet structure and is arranged on the surface layer of the rotor in the circumferential direction and corresponds to the stator assembly in the motor shell to form a magnetic suspension structure.

When the blood pump is actually applied, the volume of the motor is reduced, so that the volume of the blood pump is reduced, and the materials of parts such as a shell are reduced, so that the weight of the blood pump is reduced; simultaneously, the structure is simple, and the processing is convenient. Simultaneously, for the centrifugal pump among the prior art, this application structure advances blood mouth and goes out blood mouth distance far away relatively, can improve the stationarity that blood flows.

Drawings

Fig. 1 is a first perspective cross-sectional view of a blood pump of the present invention;

fig. 2 is a first perspective cross-sectional view of the pump body of the present invention;

fig. 3 is a schematic cross-sectional view of a second perspective of the blood pump of the present invention;

fig. 4a, 4b, and 4c are schematic diagrams illustrating the movement of the rotating shaft according to the present invention;

FIG. 5 is a schematic view of the rounding of the magnetic steel of the blood pump rotor according to the present invention;

in the figure: 1 blood inlet, 2 axial flow blades, 3 radial hydrodynamic bearings, 4 rotor magnetic steels, 401 rounding, 402 covering layers, 5 stator coils, 6 impellers, 7 upper and lower hydrodynamic bearing liquid levels, 8 motor back yokes, 9 magnetic shoes, 10 hydrodynamic bearing grooves, 11 magnetic cores, 12 bulges, 13 pump bodies, 14 rotating shafts and 15 blood inlet channels.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

An artificial heart blood pump adopting Halbach magnetic steel technology comprises a pump body 13 and a rotor assembly positioned in the pump body 13; the pump body 13 comprises a motor shell and a sealed cavity, a blood outlet is arranged on the sealed cavity, the motor shell is positioned above the sealed cavity, and a blood inlet 1 is connected above the motor shell; the motor casing is hollow structure, is provided with stator module in the cavity of motor casing, the rotor module includes impeller 6 that pivot 14 and pivot 14 below are connected, and wherein impeller 6 is located the sealed cavity, still be provided with rotor magnet steel 4 on the pivot 14.

As shown in fig. 1, 2 and 3, when the stator coil 5 is energized, the rotor is driven to rotate, blood enters through the blood inlet 1, the axial flow blades 2 on the blood inlet channel 15 pressurize the blood for the first time, then the blood flows to the sealed cavity through the blood inlet channel 15, and the blood is pumped out from the blood outlet on the sealed cavity after rotating and pressurizing for the second time through the impeller 6 in the sealed cavity; the rotor is provided with rotor magnetic steel 4, the rotor magnetic steel 4 is of a permanent magnet structure, is arranged on the surface layer of the rotor and is arranged in the circumferential direction, and corresponds to a stator component in a motor shell to form a magnetic suspension structure; in the radial direction, the tension between the stator and the rotor of the motor keeps the rotor magnetic steel 4 on the rotating shaft 14 and the stator assembly on the same plane. If the rotating shaft 14 deviates upwards, as shown in fig. 4b, the impeller 6 will be subjected to a downward force to restore and maintain the rotor magnetic steel 4 on the impeller 6 and the stator assembly on a plane, and if the rotating shaft 14 deviates downwards, as shown in fig. 4c, the impeller 6 will be subjected to an upward force to restore and maintain the rotor magnetic steel 4 on the impeller 6 and the stator assembly on a plane; in the radial direction, a radial hydrodynamic bearing 3 is formed on the surfaces of the motor shell and the rotating shaft 14 to keep the impeller 6 at the central position; compared with the upper and lower stator structures adopted in the prior art, the magnetic suspension structure is formed in the axial direction,

the volume of the motor is reduced, so that the volume of the blood pump is reduced, and the materials of parts such as a shell are reduced, so that the weight of the blood pump is reduced; simultaneously, the structure is simple, and the processing is convenient.

In the present embodiment, also taking a blood pump with a volume of about 80ml as an example, the structural arrangement of the present application is adopted, the weight is only 140g, the diameter of the pump is about 44mm, and the height of the pump is about 25 mm; compared with the prior art, the structure greatly reduces the weight of the blood pump and lightens the burden of a patient; under the condition that the flow is the same, the structure of the device also reduces the rotating speed of the pump and improves the stability of blood flow.

Simultaneously this application selection sets up the permanent magnet on stator module, sets up the impeller for permanent magnet structure among the prior art, has not only reduced the cost to reduce the influence of magnetic suspension structure to blood output, ensured the stability of blood output.

In the application, the rotor magnetic steel 4 comprises two or more groups of permanent magnet structures, each permanent magnet structure comprises four or more permanent magnets which form even number pieces, each permanent magnet is arranged in sequence, the arrangement directions of the two permanent magnets at intervals are consistent, the magnetic field directions are opposite, and the arrangement directions of the two adjacent permanent magnets are vertical. In the implementation, four groups of permanent magnet structures can be selected to be sequentially arranged on the surface layer of the rotating shaft 14, and each group of permanent magnet structures contains sheet permanent magnets, as shown in the figure, the arrangement sequence of the permanent magnets of each group of permanent magnet structures is ↓, ←, →; the magnetic field sine distribution degree is high, the harmonic magnetic field influence is small, and the torque ripple of the pump can be reduced, so that the volume of the blood pump can be further reduced, and the weight of the impeller 6 is reduced; the axial flow blades 2 are arranged in the blood inlet channel 15, so that the lift of the outlet of the blood pump can be ensured, and the blood pump is maintained in a low rotating speed to provide large flow; can improve the smoothness of blood flow.

Further, as shown in fig. 1, in the present application, a blood inlet passage 15 is provided in the rotary shaft 14, and the axial flow blade 2 is provided in the blood inlet passage 15. The blood inlet channel 15 is communicated with the blood inlet and the blood outlet, and the axial flow blades 2 arranged on the blood inlet channel 15 in the application means that the axial flow blades 2 are arranged on the inner wall of the rotating shaft 14 in the blood inlet channel 15, so that the lift of the outlet of the blood pump can be ensured, and the blood pump is maintained in a low rotating speed to provide large flow; can improve the smoothness of blood flow. Compared with the existing single centrifugal pump, the rotating speed of the impeller is reduced under the condition of obtaining the same flow; specifically, in order to maintain good heart operation, the performance of the blood pump not only has the requirements of flow rate, rotation speed, but also lift, the pump in the prior art can only increase the rotation speed of the impeller in order to achieve higher lift in the working process, the higher the rotation speed is, the greater the damage to red blood cells in blood is, and the damage to the red blood cells caused by high shear force mainly due to high rotation speed is quite large; therefore, in order to ensure the quality of pumped blood and reduce the damage to red blood cells, the axial flow blades are arranged in the blood inlet channel, so that the lift of the outlet of the blood pump can be ensured, and the blood pump is maintained in a low rotating speed.

In addition, because the application structure advances blood mouth and goes out the blood mouth distance relatively far away, because the rotation of impeller, can lead to advancing the suction of blood mouth department big, produce the negative pressure easily, and then the hematocyte can cause the hemolysis, through increasing axial compressor blade in advancing the blood passageway, can eliminate negative pressure zone, avoid the hemolysis, let internal blood flow more steady.

Compared with a multistage pump in other structures, the structure has the advantages that the problems of hemolysis and pump body volume are solved if the multistage pump is applied to the structure, the complexity of a complex system is greatly improved if one set of axial flow system is added, and the possibility and cost of failure are increased.

In this embodiment, also taking a blood pump with a volume of about 80ml as an example, if the pump head pressure is 120mmHg and the flow rate reaches 10L/min, the rotation speed in the prior art is about 3600 rpm, while the rotation speed measured by the structure of the present application is only about 2600 rpm; the rotating speed of the pump is greatly reduced, and the stability of blood flow is improved; the blood pump has the advantages of small volume, light weight, low rotating speed, large flow and the like.

Furthermore, in order to make the blood flow more stable, the axial flow blades 2 can be set to be 2 or more than 2, and are symmetrically arranged inside the blood inlet channel 15 and can form an integrated or split type with the blood inlet channel 15, and the axial flow blades 2 are symmetrically arranged, so that the blood flow is stable, the stress of the rotating shaft 14 is uniform, the rotation is more stable, and the service life of the rotating shaft is prolonged; in other embodiments of the present application, a plurality of axial flow blades 2 may be overlapped, that is, a plurality of layers of axial flow blades 2 are provided, wherein the axial flow blades 2 are in a laminated structure on the inner wall of the rotating shaft 14, each layer may be provided with a plurality of blades, and the inner walls of the rotating shafts 14 of the layers may be overlapped or staggered, so as to increase the blood flow; in the actual application, can select axial flow blade 2's the position of arranging according to the dynamic balance test result of pivot 14 and impeller, axial flow blade 2 not only reaches the effect that increases blood flow in this application structure promptly, can also improve the dynamic balance nature of rotor subassembly, improves overall structure's stability. In this application structure, axial flow blade 2 mounted position preferred choice is installed in the region that 14 inner walls of pivot and rotor magnet steel 4 correspond, through setting up in this region, can improve rotor subassembly overall structure intensity to and can also reduce the impact force of blood to axial flow blade 2.

Further, as shown in fig. 3 and 5, in order to improve the sinusoidal distribution of the magnetic field and facilitate the installation and removal of the permanent magnet, in the present application, the permanent magnet is provided with a chamfer or radius 401, and the corner between the adjacent rotor magnetic steel 4 facing the stator assembly side can be selected to be a chamfer, a chamfered external corner, or a chamfered internal corner along the axial direction; particularly, when the chamfer angle distance is 1/5-1/4 of the length distance of the rotor magnetic steel 4, the magnetic field waveform of the rotor magnetic steel 4 can be closer to a standard sine waveform, so that harmonic waves can be eliminated or weakened, and the motor efficiency is improved.

Further, as shown in fig. 3 and 5, in order to ensure the sealing performance of the rotor assembly and ensure the stability of the magnetic levitation structure, a covering layer 402 is provided outside the rotor magnetic steel 4 in the present application, so as to form the radial hydrodynamic bearing 3 between the rotating shaft 14 and the motor casing.

Further, in order to ensure the blood inflow amount, the mouth part of the blood inlet 1 is provided with a taper in the present application; in addition, the inner bottom surface of the sealed cavity is provided with a conical bulge 12 which can keep a rotating shaft 14 at a central position; wherein the conical projection 12 may be provided with a platform or not, and the conical projection 12 in the present application adopts a "pointed top" structure, as shown in fig. 1 and 2, so as to split blood and reduce the impact of blood on the pump body 13.

Further, in the present application, a hydrodynamic bearing groove 10 is provided at the bottom and/or the top within the sealed cavity. Under the condition of meeting impact force, the hydrodynamic bearing grooves 10 arranged at the bottom and the top of the sealing shell form hydrodynamic suspension, so that the impeller 6 is prevented from touching the sealing shell; in the embodiment, the suspension mode combining magnetic suspension and hydrodynamic suspension is adopted, so that the shock resistance is strong and the reliability is high. Wherein the hydrodynamic bearing groove 10 can be selected to be spiral, or conical, or spherical, or inclined, specifically selected according to the hydrodynamic bearing design.

It should be understood that the examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of the present invention, those skilled in the art may make any number of changes and modifications to the present invention, and such equivalents are intended to be encompassed by the claims appended hereto.

Claims

1. An artificial heart blood pump adopting Halbach magnetic steel technology is characterized by comprising a pump body (13) and a rotor assembly positioned in the pump body (13); the pump body (13) comprises a motor shell and a sealed cavity, a bleeding hole is formed in the sealed cavity, the motor shell is located above the sealed cavity, and a blood inlet (1) is connected above the motor shell; the motor casing is hollow structure, is provided with stator module in the cavity of motor casing, the impeller (6) of rotor subassembly including pivot (14) and pivot (14) below connection, wherein impeller (6) are located the seal chamber, still be provided with rotor magnet steel (4) on pivot (14).

2. The artificial heart blood pump adopting halbach magnetic steel technology as claimed in claim 1, wherein the rotor magnetic steel (4) comprises two or more groups of permanent magnet structures, the permanent magnet structures comprise four or more permanent magnets which form even number pieces, the permanent magnets are arranged in sequence, and the two permanent magnets of one interval piece are arranged in the same direction, but the magnetic field directions are opposite, and the arrangement directions of the two adjacent permanent magnets are perpendicular.

3. The artificial heart blood pump adopting Halbach magnetic steel technology as claimed in claim 1 or 2, wherein a blood inlet channel (15) is arranged in the rotating shaft (14), and an axial flow blade (2) is arranged on the blood inlet channel (15); the axial flow blades (2) are provided with 2 or more than 2 blades.

4. The artificial heart blood pump using halbach magnet steel technology according to claim 1 or 2, characterized in that the rotor magnet steel (4) is provided with a chamfer or radius (401).

5. An artificial heart blood pump using halbach magnet steel technology according to claim 3, characterised in that the rotor magnet steel (4) is provided with a chamfer or radius (401).

6. The artificial heart blood pump adopting Halbach magnet steel technology as claimed in claim 1, 2 or 5, further comprising a covering layer (402) arranged outside the rotor magnet steel (4).

7. The artificial heart blood pump adopting Halbach magnetic steel technology as claimed in claim 3, further comprising a covering layer (402) arranged outside the rotor magnetic steel (4).

8. The artificial heart blood pump adopting Halbach magnetic steel technology as claimed in claim 4, further comprising a covering layer (402) arranged outside the rotor magnetic steel (4).

9. The artificial heart blood pump adopting Halbach magnet steel technology as claimed in claim 1, 2, 5, 7 or 8, wherein the mouth of the blood inlet (1) is tapered.

10. The artificial heart blood pump adopting Halbach magnetic steel technology as claimed in claim 3, wherein the mouth of the blood inlet (1) is tapered.

11. The artificial heart blood pump adopting Halbach magnetic steel technology as claimed in claim 4, wherein the mouth of the blood inlet (1) is tapered.

12. The artificial heart blood pump adopting Halbach magnetic steel technology as claimed in claim 6, wherein the mouth of the blood inlet (1) is tapered.

13. The artificial heart blood pump adopting Halbach magnet steel technology as claimed in claim 1, 2, 5, 7, 8, 10, 11 or 12, wherein the inner bottom surface of the sealed cavity is provided with a conical projection (12).

14. The artificial heart blood pump adopting Halbach magnetic steel technology as claimed in claim 3, wherein the inner bottom surface of the sealed cavity is provided with a conical bulge (12).

15. The artificial heart blood pump adopting Halbach magnetic steel technology as claimed in claim 4, wherein the inner bottom surface of the sealed cavity is provided with a conical bulge (12).

16. The artificial heart blood pump adopting Halbach magnetic steel technology as claimed in claim 6, wherein the inner bottom surface of the sealed cavity is provided with a conical bulge (12).

17. The artificial heart blood pump adopting halbach magnetic steel technology as claimed in claim 9, wherein the inner bottom surface of the sealed cavity is provided with a conical protrusion (12).