Magnetic suspension blood pump

Abstract

The magnetic suspension blood pump is high in integration level, small in magnetic field coupling degree and high in regulation and control precision and comprises a pump shell, an impeller, a motor unit and a magnetic suspension unit, and the axial suspension state of the impeller is jointly maintained through the magnetic acting force between an electromagnet assembly and a suspension magnet assembly and the magnetic acting force between a motor stator assembly and a motor rotor magnet; the repulsive force of the static magnetic ring array and the movable magnetic ring array maintains the radial suspension state of the impeller. The magnetic suspension unit and the motor unit are arranged at the upper end and the lower end of the impeller respectively, the distance between the magnetic suspension unit and the motor unit is increased in space, the magnetic coupling effect between the magnetic suspension unit and the motor unit is greatly reduced, control difficulty is remarkably reduced through independent control of the magnetic suspension unit and the motor unit, and system stability is improved. The special structural design improves the space utilization rate, reduces the size of the pump body, disperses a heat source and reduces the heat dissipation pressure; the bias magnetic field provided by the suspension magnet provides open-loop magnetic force in the axial direction, the closed-loop control force needing to be provided by the electromagnet assembly is greatly reduced, and the purposes of saving energy and reducing consumption are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a magnetic levitation blood pump. Background Art

[0002] Heart failure, abbreviated as HF, refers to a syndrome in which the heart's systolic function and / or diastolic function are impaired, resulting in the inability to pump venous return blood out of the heart sufficiently, leading to blood stasis in the venous system and insufficient blood perfusion in the arterial system, thereby causing a cardiac circulatory disorder syndrome. As a device for compensating and replacing the pumping function of the heart, the artificial heart provides a new medical means for HF patients. As the third-generation artificial heart, the magnetic levitation blood pump is implanted at the apex of the heart. Through magnetic levitation technology, the impeller is suspended in the pump chamber to eliminate mechanical wear and effectively transport blood. Due to its excellent characteristics of small size and good blood compatibility, it has broad application prospects. Given the usage environment limitations of the magnetic levitation blood pump, how to make the blood pump have the characteristics of high integration and small magnetic field coupling degree while meeting the functional requirements is a key technical issue that has always concerned those skilled in the art. Summary of the Invention

[0003] The object of the present invention is to provide a magnetic levitation blood pump with high integration, small magnetic field coupling degree, and high regulation accuracy.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows: A magnetic levitation blood pump includes a pump housing. The impeller is magnetically levitated and dynamically positioned at the central region of the pump housing chamber and can rotate around the central axis of the pump housing to suck blood from the inlet of the pump housing and discharge it from the outlet. The motor unit is an axial permanent magnet synchronous motor structure, including a motor stator assembly and a motor rotor magnet provided on the impeller, and the two are arranged corresponding to each other in the axial direction. The motor stator assembly provides a rotating magnetic field acting on the motor rotor to generate a rotating torque and drive the impeller to rotate. The magnetic levitation unit includes an electromagnet assembly and a suspension magnet assembly provided on the impeller, and the two are arranged corresponding to each other in the axial direction, as well as a static magnetic ring array and a dynamic magnetic ring array provided in the impeller, and the two are arranged corresponding to each other in the radial direction. The magnetic force between the electromagnet assembly and the suspension magnet assembly and the magnetic force between the motor stator assembly and the rotor magnet jointly maintain the axial suspension state of the impeller, and the repulsive force between the static magnetic ring array and the dynamic magnetic ring array maintains the radial suspension state of the impeller.

[0005] The magnetic levitation unit and the motor unit are respectively disposed in the central regions of the pump housing chambers above and below the impeller. The impeller includes an upper plate, a lower plate, and blades in the middle. The suspension magnet assembly is embedded in the upper plate, and the motor rotor magnet is embedded in the lower plate.

[0006] Further, the electromagnet assembly includes a plurality of magnetic levitation iron cores arranged at equal intervals circumferentially. The magnetic levitation iron core has a U-shaped cross-section with an opening facing the impeller, and includes a bottom plate, an outer plate and an inner plate located on the inner and outer sides of the bottom plate in the radial direction. The ends of the outer plate and the inner plate are designed as trapezoids, and the magnetic levitation coil is wound around the bottom plate.

[0007] Further, the levitation magnet assembly includes an outer annular magnet and an inner annular magnet arranged radially. The lower end faces of the outer plate and the inner plate are respectively arranged corresponding to the outer annular magnet and the inner annular magnet. Outer magnetic conduction rings and inner magnetic conduction rings with right trapezoidal cross-sections are respectively arranged on the upper end faces of the outer annular magnet and the inner annular magnet, and the right trapezoidal cross-sections of the two are arranged in mirror symmetry.

[0008] Further, a plurality of magnetic levitation iron cores are fixed on the magnetic levitation PCB board. A plurality of position sensors are arranged on the lower board surface of the magnetic levitation PCB board, and one position sensor is arranged between two adjacent magnetic levitation iron cores.

[0009] Further, the motor rotor magnet is embedded in the outer ring side inside the lower plate. The electromagnet assembly is located on the upper plate end side of the impeller, and the motor stator assembly is located on the lower plate end side of the impeller, and there are gaps.

[0010] Further, the inner cavity of the pump housing is separated by a partition into a first sealed chamber for installing the electromagnet assembly from top to bottom, a blood chamber for installing the impeller, and a second sealed chamber for installing the motor stator assembly. A diversion part protruding towards the inside of the blood chamber is arranged in the middle of the partition between the blood chamber and the second sealed chamber. The static magnetic ring array is embedded in the diversion part, and the dynamic magnetic ring array is embedded in the inner ring side inside the lower plate on the outer periphery of the diversion part. The dynamic magnetic ring array is located radially inside the motor rotor magnet and the two are arranged in an avoidance manner.

[0011] Further, the static magnetic ring array is composed of a plurality of magnetic rings axially stacked, and the dynamic magnetic ring array is also composed of a plurality of magnetic rings axially stacked. The static magnetic ring array and the dynamic magnetic ring array are coaxially arranged axially, and the dynamic magnetic ring array sleeves the outer periphery of the diversion part, forming a corresponding arrangement relationship between the static magnetic ring array and the dynamic magnetic ring array in the radial direction.

[0012] Further, the second sealed chamber is provided with a fixed column. The axis of the fixed column coincides with the axis of the blood pump. A main control PCB board is arranged on the fixed column, and the motor stator assembly is arranged in the second sealed chamber above the main control PCB board.

[0013] Further, the motor stator assembly includes a plurality of stator cores arranged at circumferential intervals. Each stator core includes a vertical plate, and a top plate is provided at the top of the vertical plate. The stator coil is wound around the outer periphery of the vertical plate. The top plate is embedded in the partition between the blood chamber and the second sealed chamber and forms a fixed connection. An annular stator yoke is provided at the bottom of the stator core, and the stator yoke fixes the plurality of stator cores into an integral structure.

[0014] Further, an inlet pipe is provided at the upper part of the pump housing. The inner cavity of the inlet pipe communicates with the blood chamber, and the outlet is provided on the side wall of the blood chamber.

[0015] The above solution has at least the following beneficial effects: The motor unit and the magnetic levitation unit are independently controlled. The sandwich structure design greatly reduces the magnetic coupling effect between the motor unit and the magnetic levitation unit, can significantly reduce the control difficulty, and improve the stability of the system. The special structure design improves the space utilization rate, reduces the overall volume of the pump body, and at the same time disperses the heat source, making it not easy to accumulate heat, and reducing the heat dissipation pressure. The bias magnetic field provided by the suspension magnet assembly provides an axial open-loop magnetic force, greatly reducing the closed-loop control force required by the electromagnet assembly, achieving the purpose of energy conservation and consumption reduction. The electromagnet assembly with a special structure can interact with the bias magnetic field more efficiently when generating the active suspension force, thereby improving the suspension efficiency of the entire magnetic levitation system, enabling the blood pump to achieve stable suspension of the impeller with lower energy consumption. The inner and outer annular magnets are aligned with the end face of the electromagnet assembly. When the impeller generates radial deflection and axial offset under the action of external force, by precisely adjusting the current of the electromagnet assemblies at different positions in the circumferential direction, the magnetic force between the electromagnet assembly and the suspension magnet assembly can be adjusted to meet the control requirements of different radial deflections and axial offset amounts. Since the magnetic field of the electromagnet assembly can be changed quickly, it can also quickly respond to the radial deflection and axial offset of the impeller. There is a radial repulsive force between the static magnetic ring array and the dynamic magnetic ring array, providing passive radial damping, which can effectively suppress the radial offset caused by external forces and achieve stable suspension and rotation of the impeller. The structure of multiple axially stacked magnetic rings provides greater flexibility for the structural design of the blood pump. The number, size, material, and arrangement of the magnetic rings can be flexibly adjusted according to the specific size and performance requirements of the blood pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the external shape diagram of the magnetic levitation blood pump; Figure 2 is the internal structure schematic diagram of the magnetic levitation blood pump; Figure 3 is the three-dimensional diagram of the motor unit and the magnetic levitation unit of the magnetic levitation blood pump; Figure 4 is Figure 3 a schematic cross-sectional view; Figure 5 is a schematic diagram of the force analysis of the blood pump impeller; Figure 6 is a schematic diagram of the magnetic field arrangement of the inner and outer magnetic ring arrays.

[0017] In the figure: 10 - pump housing, 11 - inlet, 12 - outlet, 13 - guide part, 14 - fixing column, 15 - inlet pipe, 20 - impeller, 21 - upper plate, 22 - lower plate, 23 - blade, 30 - motor unit, 31 - motor stator assembly, 311 - stator core, 311a - vertical plate, 311b - top plate, 312 - stator coil, 313 - stator yoke, 32 - motor rotor magnet, 33 - main control PCB board, 40 - magnetic levitation unit, 41 - electromagnet assembly, 411 - magnetic levitation core, 411a - bottom plate, 411b - outer side plate, 411c - inner side plate, 412 - magnetic levitation coil, 42 - suspension magnet assembly, 421 - outer ring magnet, 422 - inner ring magnet, 423 - outer magnetic conduction ring, 424 - inner magnetic conduction ring, 43 - static magnetic ring array, 44 - moving magnetic ring array, 45 - magnetic levitation PCB board, 46 - position sensor. Detailed implementation manners

[0018] For the sake of easy understanding, the terms "upper", "lower", "horizontal", "inner", "outer", etc. involved in the text indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention.

[0019] Since the magnetic levitation blood pump is implanted at the apex of the heart, the impeller is suspended in the pump chamber through magnetic levitation technology to eliminate mechanical wear and effectively transport blood. Therefore, in its design, not only biocompatibility and structural compactness need to be considered, but also its mechanical properties (efficiency of driving force, stability of levitation force and mechanical stability), electromagnetic properties (magnetic field strength, electromagnetic compatibility and power consumption) and blood compatibility (materials, structures and flow fields) need to be considered. The following combines Figures 1-5 to make a further detailed discussion on the present invention.

[0020] A magnetic levitation blood pump, comprising a pump housing 10, an impeller 20 which is magnetically levitated and dynamically positioned at the central region of the chamber of the pump housing 10 and can rotate around the central axis of the pump housing 10 to suck blood from the inlet 11 of the pump housing 10 and discharge it from the outlet 12; theoretically, the impeller 20 rotates around the central axis, but actually it is in a dynamic equilibrium state. When the impeller 20 rotates and encounters external forces resulting in radial deflection and axial offset, through the rapid response of the control system and the precise control of a plurality of circumferentially arranged electromagnets, the impeller 20 quickly resumes the equilibrium state and continues to rotate around the central axis.

[0021] The motor unit 30 is an axial permanent magnet synchronous motor structure, including a motor stator assembly 31 and a motor rotor magnet 32 provided on the impeller 20, and the two are arranged corresponding to each other in the axial direction. The motor stator assembly 31 provides a rotating magnetic field acting on the motor rotor magnet 32 to generate a rotating torque to drive the impeller 20 to rotate; this is the driving force for the rotation of the impeller 20, and the rotational speed and torque of the impeller 20 can be adjusted by controlling the current vector parameters in the motor stator assembly 31.

[0022] The magnetic levitation unit 40 includes an electromagnet assembly 41 and a suspension magnet assembly 42 provided on the impeller 20, and the two are arranged corresponding to each other in the axial direction, as well as a static magnetic ring array 43 and a dynamic magnetic ring array 44 provided in the impeller 20, and the two are arranged corresponding to each other in the radial direction; the magnetic force between the electromagnet assembly 41 and the suspension magnet assembly 42 and the magnetic force between the stator assembly 31 and the motor rotor magnet 32 jointly maintain the axial suspension state of the impeller 20, and the repulsive force between the static magnetic ring array 43 and the dynamic magnetic ring array 44 maintains the radial suspension state of the impeller 20.

[0023] The following combines Figure 5 to analyze the force condition of the impeller 20: On any cross-section passing through the central axis of the impeller 20, F1, F2, F3, F4 are the magnetic forces of the electromagnet assembly 41 on the suspension magnet assembly 42, F5, F6 are the magnetic forces of the motor stator assembly 31 on the motor rotor magnet 32, F7 and F ８ is the radial repulsive force of the static magnetic ring array 43 on the dynamic magnetic ring array 44. The suspension magnet assembly 42, the motor rotor magnet 32 and the dynamic magnetic ring array 44 are all built inside the impeller 20 to form a whole. Among them, the self-gravity of the impeller 20 and the buoyancy of the blood on it are both forces of a relatively small magnitude and can be ignored. In this case, the resultant force of F1 + F2 + F3 + F4 and the resultant force of F5 + F6 are balanced with each other in the axial direction, and the impeller 20 is in a stable suspension state in the axial direction. F ７ and F ８ provide damping forces for the radial direction of the impeller 20, and the impeller 20 is in a stable suspension state in the radial direction. In summary, the impeller 20 is in dynamic equilibrium in both the axial and radial directions, thus ensuring the stable suspension of the impeller 20.

[0024] The magnetic levitation unit 40 and the motor unit 30 are respectively disposed in the central region of the chamber of the pump casing 10 above and below the impeller 20. The impeller 20 includes an upper plate 21, a lower plate 22 and blades 23 in the middle. The levitation magnet assembly 42 is embedded in the upper plate 21, and the motor rotor magnet 32 is embedded in the lower plate 22.

[0025] In the present invention, the motor unit 30 and the magnetic levitation unit 40 are controlled separately. The magnetic levitation unit 40 and the motor unit 30 are respectively disposed in the central region of the chamber of the pump casing 10 above and below the impeller 20. This sandwich structure design greatly reduces the magnetic coupling effect between the motor unit 30 and the magnetic levitation unit 40, can significantly reduce the control difficulty, improve the stability of the system, can further improve the space utilization rate, reduce the overall volume of the pump body, and at the same time disperse the heat source, making it not easy to accumulate heat and reducing the heat dissipation pressure.

[0026] Meanwhile, the suspension magnet assembly 42, as a permanent magnet, can generate a bias magnetic field. The existence of the bias magnetic field has at least the following beneficial effects: (1) The impeller 20 needs to be suspended in the central area of the chamber of the pump housing 10 to achieve contactless rotation, eliminating mechanical wear, thereby greatly reducing the damage to blood. The bias magnetic field provided by the suspension magnet provides an open-loop magnetic force in the axial direction for the impeller 20, greatly reducing the closed-loop control force required for the electromagnet assembly 41 to maintain the suspension of the impeller 20. Without the bias magnetic field, the electromagnet assembly 41 needs to consume more electrical energy to generate a large enough magnetic force to overcome other forces such as the gravity of the impeller 20 and the magnetic suction force of the motor unit. With the bias magnetic field, the electromagnet assembly 41 only needs to make fine adjustments on this basis, greatly reducing the requirement for the magnetic flux of the electromagnet assembly 41, achieving the purpose of energy conservation and consumption reduction. (2) The bias magnetic field provides a stable starting point for the suspension of the impeller 20, enabling the impeller 20 to obtain an open-loop magnetic force without active control, laying a foundation for subsequent precise suspension control through the electromagnet assembly 41 to eliminate the radial deflection and axial offset of the impeller caused by external forces. (3) The bias magnetic field forms a stable magnetic flux distribution in the air gap through the high energy product of the suspension magnet assembly 42, providing a basic supporting force for the impeller 20; when the impeller 20 deviates from the equilibrium position, the superposition or cancellation effect of the bias magnetic field and the control magnetic field (such as the difference in the main air gap magnetic flux density) can quickly generate a restoring force, enhancing the load-bearing capacity and dynamic stability of the system. (4) Although the bias magnetic field is open-loop unstable, it can provide position information for the suspension of the impeller 20. When the blood pump is disturbed by factors such as external vibration and blood flow changes during operation, the magnetic flux passing through the position sensor of the bias magnetic field will change, causing the voltage signal output by the position sensor to change relative to the voltage signal output at the equilibrium position. After a series of calculations in the main control, the position change amount of the impeller 20 is obtained, and a corresponding adjustment signal is output, which is input to the electromagnet assembly 41 through a power amplifier, achieving the purpose of active control, enabling the impeller 20 to quickly return to the stable suspension state, and providing a stable passive signal for the control of the entire magnetic levitation blood pump system.

[0027] As a preferred embodiment of the present invention, the electromagnet assembly 41 includes a plurality of magnetic suspension cores 411 evenly spaced along the circumferential direction, the magnetic suspension core 411 is a structure with a U-shaped cross section and an opening facing the impeller, including a bottom plate 411a, and an outer plate 411b and an inner plate 411c located on both radial inner and outer sides of the bottom plate 411a, and the ends of the outer plate 411b and the inner plate 411c are designed to be trapezoidal to reduce the area of the end face. Under the condition that the magnetic flux of the entire magnetic flux path remains unchanged, and under the premise of not triggering the magnetic saturation effect of the magnetic suspension core 411, the area of the end face can be appropriately reduced, and the magnetic induction intensity passing through the end face can be increased, thereby appropriately increasing the magnetic force at the corresponding position. The magnetic levitation coil 412 is wound on the base plate 411a. At the same time, multiple magnetic levitation cores 411 are arranged at intervals along the circumferential direction, and the arrangement direction of each magnetic levitation core 411 extends radially. The magnetic levitation coil 412 is wound on the base plate 411a, that is, the direction of the magnetic levitation coil 412 is wound radially. This winding method helps to make full use of the space and avoid mutual interference between adjacent coils. When the upper limit of the closed-loop control force meets the actual application, there is enough space to select thicker enameled copper wire for winding, thereby reducing resistance and thus reducing heat and unnecessary energy loss.

[0028] The suspension magnet assembly 42 includes an outer ring magnet 421 and an inner ring magnet 422 arranged radially, the lower end faces of the outer plate 411b and the inner plate 411c are arranged corresponding to the outer ring magnet 421 and the inner ring magnet 422 respectively, and the upper end faces of the outer ring magnet 421 and the inner ring magnet 422 are also provided with an outer magnetic conductive ring 423 and an inner magnetic conductive ring 424 with a right-angled trapezoidal cross section, and the right-angled trapezoidal cross sections of the two are arranged in mirror symmetry. This design has two purposes, one is that the right-angled trapezoidal design has the same purpose as the trapezoidal design of the ends of the outer plate 411b and the inner plate 411c, in order to increase the magnetic induction intensity through the end faces of the outer magnetic conductive ring 423 and the inner magnetic conductive ring 424, thereby increasing the magnetic force; the second is that the purpose of the symmetrical design is to widen the distance between the upper end faces of the two trapezoids as much as possible, thereby reducing the degree of bias magnetic field coupling as much as possible. In summary, when the outer magnetic ring 423 and the inner magnetic ring 424 cooperate with the permanent magnet to form a bias magnetic field system, the design of the right-angle trapezoidal cross section can optimize the properties of the magnetic suspension system. The outer magnetic ring 423 and the inner magnetic ring 424 can guide the magnetic field lines and can better cooperate with the end of the magnetic suspension core 411, so that the magnetic field distribution of the gap space corresponding to the end face of the magnetic suspension core 411 and the end face of the outer magnetic ring 423 and the inner magnetic ring 424 is more concentrated, and the magnetic force is increased and the leakage magnetic phenomenon is reduced under the condition of unchanged magnetic flux, thereby improving the utilization rate of the magnetic field. In this way, the electromagnet assembly 41 can interact with the bias magnetic field more efficiently when generating a closed-loop control force, thereby improving the suspension efficiency of the entire magnetic suspension system, so that the blood pump can achieve stable suspension of the impeller 20 with lower energy consumption.

[0029] If the impeller 20 undergoes radial deflection and axial offset, the magnetic flux of the bias magnetic field generated by the outer ring magnet 421 and the inner ring magnet 422 in the iron core of the electromagnet assembly 41 will change, resulting in the bias magnetic field force being larger or smaller than the relative equilibrium position. Since the magnetic force generated by the bias magnetic field is in an open-loop state and cannot be feedback-regulated, at this time, it is necessary to actively adjust the current in the magnetic suspension coil 412 of each electromagnet assembly 41 to compensate for the bias magnetic field, and actively pull the impeller 20 back to the original equilibrium position. By precisely adjusting the magnitude and direction of the current in the electromagnet assembly 41, the magnetic force of the bias magnetic field is accurately compensated to adapt to different radial deflections, axial offsets, and control requirements.

[0030] Multiple magnetic suspension iron cores 411 are fixed on the magnetic suspension PCB board 45. On the one hand, the magnetic suspension PCB board 45 fixes the multiple magnetic suspension iron cores 411 together to ensure that each magnetic suspension iron core 411 is on the same circumference. The magnetic suspension iron core 411 is provided with a plurality of position sensors 46 on the lower plate surface of the magnetic suspension PCB board 45, and one position sensor 46 is arranged between two adjacent magnetic suspension iron cores 411. The position sensor 46 collects the real-time position of the impeller 20, and the control unit quickly adjusts the current of the corresponding magnetic suspension coil 412 according to the position signal to realize the stable control of the closed-loop control force on the axial direction of the impeller 20.

[0031] Furthermore, the motor rotor magnet 32 is embedded in the outer ring side inside the lower plate 22. The electromagnet assembly 41 is located on the end side of the upper plate 21 of the impeller 20, and the motor stator assembly 31 is located on the end side of the lower plate 22 of the impeller 20, and there are gaps. The motor unit 30 and the magnetic suspension unit 40 are respectively arranged at the lower and upper parts of the impeller. This sandwich structure design maximally separates the motor unit 30 and the magnetic suspension unit 40 within a limited space, greatly reducing the magnetic coupling effect between the motor unit 30 and the magnetic suspension unit 40, significantly reducing the control difficulty, improving the stability of the system, further improving the space utilization rate, reducing the overall volume of the pump body, and at the same time dispersing the heat source, making it not easy to accumulate heat and reducing the heat dissipation pressure.

[0032] The inner cavity of the pump housing 10 is partitioned by a partition into a first sealed chamber A for installing the electromagnet assembly 41 from top to bottom, a blood chamber B for installing the impeller 20, and a second sealed chamber C for installing the motor stator assembly 31. In the middle of the partition between the blood chamber B and the second sealed chamber C, a guiding portion 13 protruding inward into the blood chamber C is provided. The static magnetic ring array 43 is embedded in the guiding portion 13, and the dynamic magnetic ring array 44 is embedded in the inner ring side of the lower plate 22 outside the guiding portion 13. The guiding portion 13 is used for installing the static magnetic ring array 43 on the one hand and guiding the blood flow to increase the lift on the other hand. Using a partition to divide the pump chamber into the first sealed chamber A, the blood chamber B, and the second sealed chamber C makes the overall structure compact, fully utilizes the space, and further reduces the volume of the entire blood pump. The first sealed chamber A, the second sealed chamber C, and the blood chamber B are isolated from each other, and no blood, impurities, etc. will enter the sealed chamber, and only the magnetic field is allowed to pass through, thus ensuring the stability of the performance of the motor stator assembly 31 and the electromagnet assembly 41. The motor rotor magnet 32, the suspension magnet assembly 42, and the dynamic magnetic ring array 44 in the impeller 20 are all embedded inside the impeller 20 and will not directly contact the blood in the blood chamber B, avoiding the corrosion of the magnet by the blood. The dynamic magnetic ring array 44 is located radially inside the motor rotor magnet 32 and the two are arranged in an avoidance manner, reasonably utilizing the space of the lower plate 22 to further reduce the volume and weight of the entire blood pump.

[0033] Preferably, the static magnetic ring array 43 is composed of a plurality of magnetic rings axially stacked, and the dynamic magnetic ring array 44 is also composed of a plurality of magnetic rings axially stacked. The static magnetic ring array 43 and the dynamic magnetic ring array 44 are coaxially arranged axially, and the dynamic magnetic ring array 44 sleeves the outside of the guiding portion 13, forming a relationship in which the static magnetic ring array 43 and the dynamic magnetic ring array 44 are arranged corresponding to each other radially. Combining Figure 6 with the magnetic field arrangement situation, the static magnetic ring array 43 and the dynamic magnetic ring array 44 can provide a radial damping force to keep the position of the impeller 20 relatively balanced in the radial direction. The structure of a plurality of axially stacked magnetic rings provides greater flexibility for the structural design of the blood pump, and the number, size, and arrangement of the magnetic rings can be flexibly adjusted according to the specific size and performance requirements of the blood pump.

[0034] To fix the motor stator assembly 31, the second sealed chamber C is provided with a fixing column 14. The axis of the fixing column 14 coincides with the axis of the blood pump. A main control PCB board 33 is provided on the fixing column 14. The motor stator assembly 31 is arranged in the second sealed chamber C above the main control PCB board 33. The motor stator assembly 31 is fixed to the fixing column 14 through the main control PCB board 33 to ensure the stability of the position of the motor stator assembly 31.

[0035] Specifically, the motor stator assembly 31 includes a plurality of stator cores 311 circumferentially spaced apart. The stator core 311 includes a vertical plate 311a, and a top plate 311b is provided at the top of the vertical plate 311a. The stator coil 312 is wound around the outer periphery of the vertical plate 311a. The top plate 311b is embedded in the partition between the blood chamber B and the second sealing chamber C and forms a fixed connection. A ring-shaped stator yoke 313 is provided at the bottom of the stator core 311, and the stator yoke 313 fixes the plurality of stator cores 311 into an integral structure. The lower part of the stator core 311 is fixed to the main control PCB board 33, and the upper part is fixed to the partition, which can be regarded as being fixed to the pump housing 10 at both ends, with a stable and firm position.

[0036] Furthermore, an inlet pipe 15 is provided at the upper part of the pump housing 10. The inner cavity of the inlet pipe 15 communicates with the blood chamber B. The outlet 12 is provided on the side wall of the blood chamber B. The inlet pipe 15 is a slender tube and is used to be implanted into the ventricle from the apex of the heart. A connecting pipe is connected to the outlet 12. When the blood pump operates, the blood in the ventricle enters the blood chamber B through the inlet pipe 15 and is pumped to the target position from the outlet 12, thereby achieving the purpose of assisting the heart in pumping blood.

[0037] It should be noted that some embodiments of the present application are described above. Other embodiments are within the scope of the appended claims. In some cases, the solutions or steps recited in the claims can be executed in a different order from that in the above embodiments and still achieve the desired results. Additionally, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A magnetic levitation blood pump, characterized in that: It includes a pump housing (10), an impeller (20) which is magnetically levitated and dynamically positioned at the central area of the chamber of the pump housing (10) and can rotate around the central axis of the pump housing (10) to suck blood from the inlet (11) of the pump housing (10) and discharge it from the outlet (12); The motor unit (30) is an axial permanent magnet synchronous motor structure, including a motor stator assembly (31) and a motor rotor magnet (32) arranged in the impeller (20), and the two are arranged axially corresponding to each other. The motor stator assembly (31) provides a rotating magnetic field acting on the motor rotor magnet (32) to generate a rotating torque to drive the impeller (20) to rotate; The magnetic levitation unit (40) includes an electromagnet assembly (41) and a suspension magnet assembly (42) arranged in the impeller (20), and the two are arranged axially corresponding to each other, as well as a static magnetic ring array (43) and a moving magnetic ring array (44) arranged in the impeller (20), and the two are arranged radially corresponding to each other. The magnetic force between the electromagnet assembly (41) and the suspension magnet assembly (42) and the magnetic force between the motor stator assembly (31) and the motor rotor magnet (32) jointly maintain the axial suspension state of the impeller (20), and the repulsive force between the static magnetic ring array (43) and the moving magnetic ring array (44) maintains the radial suspension state of the impeller (20); The magnetic levitation unit (40) and the motor unit (30) are respectively arranged in the central area of the chamber of the pump housing (10) above and below the impeller (20). The impeller (20) includes an upper plate (21), a lower plate (22) and blades (23) in the middle. The suspension magnet assembly (42) is embedded in the upper plate (21), and the motor rotor magnet (32) is embedded in the lower plate (22).

2. The magnetic levitation blood pump according to claim 1, characterized in that: The electromagnet assembly (41) includes a plurality of magnetic levitation iron cores (411) arranged at equal intervals along the circumference. The magnetic levitation iron core (411) has a U-shaped cross-section with an opening facing the impeller, including a bottom plate (411a), and outer plates (411b) and inner plates (411c) located on the radial outer side and inner side of the bottom plate (411a). The ends of the outer plate (411b) and the inner plate (411c) are designed as trapezoids, and the magnetic levitation coil (412) is wound on the bottom plate (411a).

3. The magnetic levitation blood pump according to claim 2, wherein: The suspension magnet assembly (42) includes a radially arranged outer ring magnet (421) and an inner ring magnet (422). The lower end faces of the outer plate (411b) and the inner plate (411c) are respectively arranged corresponding to the outer ring magnet (421) and the inner ring magnet (422). The upper end faces of the outer ring magnet (421) and the inner ring magnet (422) are respectively provided with an outer magnetic conduction ring (423) and an inner magnetic conduction ring (424) with a right trapezoidal cross-section, and the right trapezoidal cross-sections of the two are arranged in mirror symmetry.

4. The magnetic levitation blood pump according to claim 2, wherein: A plurality of magnetic levitation iron cores (411) are fixed on the magnetic levitation PCB board (45). A plurality of position sensors (46) are arranged on the lower board surface of the magnetic levitation PCB board (45), and one position sensor (46) is arranged between two adjacent magnetic levitation iron cores (411).

5. The magnetic levitation blood pump according to claim 2, wherein: The motor rotor magnet (32) is embedded in the outer ring side within the lower plate (22). The electromagnet assembly (41) is located on the end side of the upper plate (21) of the impeller (20), and the motor stator assembly (31) is located on the end side of the lower plate (22) of the impeller (20), with gaps therebetween.

6. The magnetic levitation blood pump according to claim 5, wherein: The inner cavity of the pump housing (10) is partitioned by a partition into a first sealed chamber (A) for installing the electromagnet assembly (41) from top to bottom, a blood chamber (B) for installing the impeller (20), and a second sealed chamber (C) for installing the motor stator assembly (31). In the middle of the partition between the blood chamber (B) and the second sealed chamber (C), a diversion portion (13) protruding towards the inside of the blood chamber (B) is provided. The static magnetic ring array (43) is embedded in the diversion portion (13), and the dynamic magnetic ring array (44) is embedded in the inner ring side within the lower plate (22) on the outer periphery of the diversion portion (13). The dynamic magnetic ring array (44) is located radially inside the motor rotor magnet (32), and the two are arranged in an avoiding manner.

7. The magnetic levitation blood pump according to claim 6, characterized in that: The static magnetic ring array (43) is composed of a plurality of magnetic rings axially stacked. The dynamic magnetic ring array (44) is also composed of a plurality of magnetic rings axially stacked. The static magnetic ring array (43) and the dynamic magnetic ring array (44) are coaxially arranged axially, and the dynamic magnetic ring array (44) sleeved around the outer periphery of the diversion portion (13), forming a relationship in which the static magnetic ring array (43) and the dynamic magnetic ring array (44) are arranged corresponding to each other radially.

8. The magnetic levitation blood pump according to claim 6, wherein: A fixing column (14) is provided in the second sealed chamber (C). The axis of the fixing column (14) coincides with the axis of the blood pump. A main control PCB board (33) is provided on the fixing column (14), and the motor stator assembly (31) is arranged in the second sealed chamber (C) above the main control PCB board (33).

9. The magnetic levitation blood pump according to claim 6, wherein: The motor stator assembly (31) includes a plurality of stator cores (311) circumferentially spaced apart. Each stator core (311) includes a vertical plate (311a). A top plate (311b) is provided at the top of the vertical plate (311a). The stator coil (312) is wound around the outer periphery of the vertical plate (311a). The top plate (311b) is embedded in the partition between the blood chamber (B) and the second sealed chamber (C) and forms a fixed connection. A ring-shaped stator yoke (313) is provided at the bottom of the stator core (311), and the stator yoke (313) fixes the plurality of stator cores (311) into an integral structure.

10. The magnetic levitation blood pump according to claim 6, wherein: An inlet pipe (15) is provided at the upper part of the pump housing (10). The inner cavity of the inlet pipe (15) communicates with the blood chamber (B). The outlet (12) is provided on the side wall of the blood chamber (B).

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