Magnetic levitation blood pump structure

Abstract

The application is a magnetic suspension blood pump structure with high integration and high system stability, comprising a pump shell, an impeller, a magnetic suspension unit and a motor unit, the magnetic force between the electromagnet assembly and the suspension magnet assembly and the magnetic force between the static magnet ring and the dynamic magnet ring jointly maintain the suspension state of the impeller. When the impeller is radially offset, the direction of the magnetic force of the two is no longer parallel to the axial direction, and a component force opposite to the radial displacement direction is generated in the radial direction, thereby inhibiting the radial offset of the impeller. The motor unit and the magnetic suspension unit are separately controlled, the sandwich structure design enlarges the spacing between the motor unit and the magnetic suspension unit, greatly reduces the magnetic coupling effect, significantly reduces the control difficulty, improves the stability of the system, disperses the heat source, is not easy to accumulate heat, and reduces the heat dissipation pressure. The special motor unit structure design improves the space utilization rate, reduces the pump body volume, the bias magnetic field provided by the suspension magnet assembly provides an open-loop magnetic force, and the purpose of energy saving and consumption reduction is achieved.

Description

Technical Field

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

[0002] Heart failure, also known as HF, is a condition characterized by impaired systolic and / or diastolic function, which prevents adequate venous return from the heart. This leads to venous congestion and insufficient arterial perfusion, resulting in a complex syndrome of cardiac circulatory disorders. Artificial hearts, designed to supplement and replace the heart's pumping function, offer a new medical treatment for patients with heart failure. The magnetic levitation blood pump, a third-generation artificial heart, is implanted at the apex of the heart. Using magnetic levitation technology, the impeller suspends within the pump chamber, eliminating mechanical wear and enabling efficient blood delivery. Its compact size and excellent blood compatibility hold broad application prospects. Given the environmental limitations of magnetic levitation blood pumps, achieving high integration and system stability while maintaining functional performance remains a key technical challenge for those skilled in the art. Summary of the Invention

[0003] The object of the present invention is to provide a magnetic levitation blood pump structure with high integration and high system stability.

[0004] To achieve the above-mentioned object, the present invention adopts the following technical solutions: a magnetically suspended blood pump structure, comprising a pump housing, an impeller magnetically suspended and dynamically positioned in the central area of ​​a pump housing chamber and capable of rotating about the central axis of the pump housing to draw blood from an inlet of the pump housing and discharge it from an outlet;

[0005] The motor unit is an axial permanent magnet synchronous motor structure, including a motor stator assembly and a motor rotor magnet disposed in the impeller, and the two are arranged correspondingly in the radial direction. The motor stator assembly provides a rotating magnetic field acting on the motor rotor magnet, generating a rotational torque to drive the impeller to rotate;

[0006] The magnetic levitation unit includes an electromagnet assembly and a levitation magnet assembly mounted on the impeller, both arranged axially in correspondence, as well as a static magnetic ring and a dynamic magnetic ring mounted in the impeller, both arranged axially in correspondence. The magnetic forces between the electromagnet assembly and the levitation magnet assembly, and between the static magnetic ring and the dynamic magnetic ring, collectively maintain the impeller's levitation. When the impeller deflects radially, the direction of these magnetic forces no longer parallels the axial direction, generating a radial force component opposite to the radial displacement direction, thereby suppressing radial deflection of the impeller.

[0007] The magnetic levitation unit and the motor unit are respectively placed in the central area of ​​the pump casing chamber above and below the impeller. The impeller includes an upper plate, a lower plate and blades in the middle. The levitation magnet assembly is embedded in the upper plate, and the motor rotor magnet is embedded in the lower plate.

[0008] The electromagnet assembly includes a plurality of magnetic levitation cores arranged evenly spaced circumferentially. The magnetic levitation core is a structure with a U-shaped cross-section and an opening facing the impeller. It includes a base plate, and outer and inner plates located radially outside and inside the base plate. The ends of the outer and inner plates are designed to be trapezoidal, and the magnetic levitation coil is wound on the base plate.

[0009] The suspension magnet assembly includes a radially arranged outer ring magnet and an inner ring magnet. The lower end surfaces of the outer plate and the inner plate are arranged corresponding to the outer ring magnet and the inner ring magnet respectively. The upper end surfaces of the outer ring magnet and the inner ring magnet are also respectively provided with an outer magnetic conductive ring and an inner magnetic conductive ring with a right-angled trapezoidal cross-section, and the right-angled trapezoidal cross-sections of the two are arranged in mirror symmetry.

[0010] A plurality of magnetic levitation iron cores are fixed on a magnetic levitation PCB board. A plurality of position sensors are provided on the lower surface of the magnetic levitation PCB board. One position sensor is provided between each of two adjacent magnetic levitation iron cores.

[0011] The impeller includes an upper plate, a lower plate and blades in the middle. The suspension magnet assembly is embedded in the upper plate, the motor rotor magnet is embedded in the inner ring side of the lower plate, and the dynamic magnetic ring is embedded in the lower plate and located radially outside the motor rotor magnet.

[0012] The inner cavity of the pump casing is divided by a partition into a first sealed chamber for installing the electromagnet assembly, a blood chamber for installing the impeller, and a second sealed chamber for installing the motor stator assembly from top to bottom. A guide portion protruding toward the inside of the blood chamber is provided in the middle of the partition between the blood chamber and the second sealed chamber. The motor stator assembly is provided in the cavity of the guide portion and the second sealed chamber.

[0013] The motor stator assembly includes a plurality of stator cores arranged at circumferential intervals. The cross-section of the stator core is in the shape of a "<" and includes a vertical plate and a top plate located on the top of the vertical plate and extending radially outward. The stator coil is wound around the outer circumference of the vertical plate, and the end face of the top plate is arranged radially corresponding to the motor rotor magnet. The motor rotor magnet is radially magnetized.

[0014] An annular stator yoke is provided at the bottom of the stator core, and the stator yoke fixes multiple stator cores into an integrated structure. A main control PCB board is provided in the second sealed chamber.

[0015] The static magnetic ring is embedded in the partition between the blood chamber and the second sealed chamber.

[0016] An inlet pipe is arranged on the upper part of the pump housing, the inner cavity of the inlet pipe is communicated with the blood cavity, and the outlet is arranged on the side wall of the blood cavity.

[0017] The above scheme has at least the following beneficial effects:

[0018] 1. The motor unit and magnetic levitation unit are controlled separately. The sandwich structure design increases the distance between the motor unit and the magnetic levitation unit, greatly reducing the magnetic coupling effect, significantly reducing the control difficulty and improving the stability of the system.

[0019] 2. The special structural design improves space utilization, reduces the overall volume of the pump body, and disperses the heat source, making it difficult to accumulate heat and reducing heat dissipation pressure.

[0020] 3. The bias magnetic field provided by the suspension magnet assembly provides open-loop magnetic force, which greatly reduces the closed-loop control force required by the electromagnet assembly, thereby achieving the purpose of energy saving and consumption reduction.

[0021] 4. The specially structured electromagnet assembly can interact with the bias magnetic field more efficiently when generating active levitation force, thereby improving the levitation efficiency of the entire magnetic levitation system and enabling the blood pump to achieve stable levitation of the impeller with lower energy consumption.

[0022] 5. The magnetic force between the electromagnet assembly and the suspension magnet assembly, as well as the magnetic force between the static magnetic ring and the dynamic magnetic ring, jointly maintains the impeller's suspension state. If the impeller deflects radially, the direction of the two magnetic forces will no longer be parallel to the axial direction, thus generating a radial component opposite to the radial displacement direction, thereby suppressing the impeller's radial deflection.

[0023] 6. The arrangement of the motor stator assembly and the motor rotor magnet can ensure that the stator core and the motor rotor magnet can form a specific annular magnetic circuit, thereby improving the pumping efficiency and stability of the blood pump, while also saving radial space.

[0024] 7. The design of the motor stator assembly combining radial stator teeth and axial stator core prevents the motor unit from generating axial force, thereby reducing the bearing pressure of the axial magnetic suspension. At the same time, this structure is conducive to the rational use of space and the reduction of the size of the blood pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the appearance diagram of the magnetic levitation blood pump;

[0026] Figure 2 Schematic diagram of the internal structure of the magnetic levitation blood pump;

[0027] Figure 3 A three-dimensional diagram of a motor unit and a magnetic levitation unit of a magnetic levitation blood pump;

[0028] Figure 4 for Figure 3 Schematic cross-section diagram of ;

[0029] Figure 5 Schematic diagram of the force analysis of the blood pump impeller.

[0030] 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- blades, 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 plate, 411c-inner plate, 412-magnetic levitation coil, 42-levitation magnet assembly, 421-outer ring magnet, 422-inner ring magnet, 423-outer magnetic ring, 424-inner magnetic ring, 43-static magnetic ring, 44-dynamic magnetic ring, 45-magnetic levitation PCB board, 46-position sensor. DETAILED DESCRIPTION

[0031] For ease of understanding, the terms "upper", "lower", "horizontal", "inside", "outside", etc. involved in the text indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0032] 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, it is necessary to consider not only biocompatibility and structural compactness, 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, structure and flow field). Figure 1-Figure 5 The present invention is described in further detail.

[0033] See Figures 1-4 As shown, a magnetic levitation blood pump structure includes a pump housing 10, an impeller 20 that is magnetically levitated and dynamically positioned in the central area of ​​the chamber of the pump housing 10 and can rotate around the central axis of the pump housing 10 to draw 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 in reality it is in a dynamic equilibrium state. When the impeller 20 encounters external forces during rotation, resulting in radial deflection and axial displacement, the control system quickly responds and accurately controls multiple circumferentially arranged electromagnets, so that the impeller 20 quickly recovers the equilibrium state and continues to rotate around the central axis.

[0034] The motor unit 30 is an axial permanent magnet synchronous motor structure, comprising a motor stator assembly 31 and a motor rotor magnet 32 ​​disposed in the impeller 20, both of which are arranged radially in correspondence. The motor stator assembly 31 provides a rotating magnetic field that acts on the motor rotor magnet 32, generating a rotational torque that drives the impeller 20 to rotate. The driving force for the impeller 20's rotation can be adjusted by controlling the current vector parameters in the motor stator assembly 31 to adjust the speed and torque of the impeller 20.

[0035] The magnetic levitation unit 40 includes an electromagnet assembly 41 and a levitation magnet assembly 42 mounted on the impeller 20, both arranged axially in correspondence with each other, as well as a static magnetic ring 43 and a dynamic magnetic ring 44 mounted within the impeller 20, both arranged axially in correspondence with each other. The magnetic forces between the electromagnet assembly 41 and the levitation magnet assembly 42, and between the static magnetic ring 43 and the dynamic magnetic ring 44, jointly maintain the levitation of the impeller 20. If the impeller 20 deflects radially, the directions of the magnetic forces are no longer parallel to the axial direction, generating a radial force component opposite to the radial displacement direction, thereby suppressing radial deflection of the impeller 20.

[0036] The following combination Figure 5 Let's analyze the forces acting on impeller 20: At any cross-section passing through the central axis, F1, F2, F3, and F4 are the magnetic forces exerted by electromagnet assembly 41 on levitation magnet assembly 42; F5 and F6 are the magnetic forces exerted by motor stator assembly 31 on motor rotor magnet 32; and F7 and F8 are the magnetic forces between static magnetic ring 43 and dynamic magnetic ring 44. Levitation magnet assembly 42, motor rotor magnet 32, and dynamic magnetic ring 44 are all integrated into the impeller, forming a single unit. The gravity and buoyancy forces acting on impeller 20 are both negligible and of relatively small magnitude. When impeller 20 is in a balanced state of suspension, the angles between F1, F2, F3, F4, F7, and F8 and the axial direction are zero, and F1 + F2 + F3 + F4 and F7 + F8 are axially balanced. If impeller 20 deflects radially, and the angles between F1, F2, F3, F4, F7, and F8 and the axial direction are no longer zero, F1, F2, F3, F4, F7, and F8 will generate radial force components, always pointing in the opposite direction of the displacement, thereby suppressing radial deflection of impeller 20. Vector control of motor unit 30 adjusts the magnitudes of F5 and F6 to assist in radial balance and ensure stable suspension. In summary, impeller 20 is in dynamic balance in both the axial and radial directions, ensuring stable suspension of impeller 20.

[0037] The magnetic levitation unit 40 and the motor unit 30 are respectively placed in the central area of ​​the pump casing 10 chamber above and below the impeller 20. The impeller 20 includes an upper plate 21, a lower plate 22 and a blade 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.

[0038] The motor unit 30 and the magnetic levitation unit 40 in the present invention are controlled separately. The magnetic levitation unit 40 and the motor unit 30 are respectively placed in the central area of ​​the chamber of the pump casing 10 above and below the impeller 20. This sandwich structure design increases the distance between the motor unit 30 and the magnetic levitation unit 40, greatly reducing the magnetic coupling effect, significantly reducing the control difficulty, improving the stability of the system, further improving the space utilization, reducing the overall volume of the pump body, and at the same time dispersing the heat source, preventing heat accumulation, and reducing the heat dissipation pressure.

[0039] At the same time, 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 pump housing 10 chamber to achieve contactless rotation, eliminate mechanical wear, and thus greatly reduce damage to the blood. The bias magnetic field provided by the suspension magnet provides an open-loop magnetic force for the impeller 20, which greatly reduces the closed-loop control force required by the electromagnet assembly 41 to maintain the suspension of the impeller 20. If there is no bias magnetic field, the electromagnet assembly 41 needs to consume more electrical energy to generate a sufficiently large magnetic force to overcome the magnetic force between the dynamic magnetic ring 44 and the static magnetic ring 43 and the magnetic force of the motor unit 30 and other external forces. With the bias magnetic field, the electromagnet assembly 41 only needs to be fine-tuned on this basis, which greatly reduces the demand for the magnetic flux of the electromagnet assembly 41 and achieves the purpose of energy saving and consumption reduction. (2) The bias magnetic field provides a stable starting point for the suspension of the impeller 20, allowing the impeller 20 to obtain a certain open-loop magnetic force without active control, laying the foundation for the 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 magnetic energy product of the suspension magnet assembly 42, providing basic support for the impeller 20; when the impeller 20 deviates from the equilibrium position, the superposition or offset 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 external vibrations, changes in blood flow, and other factors during operation, the magnetic flux of the bias magnetic field passing through the position sensor 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 of the impeller 20 is obtained, and the corresponding adjustment signal is output. The signal is input to the electromagnet assembly 41 through the power amplifier to achieve the purpose of active control, so that the impeller 20 can quickly return to a stable suspension state, providing a stable passive signal for the control of the entire magnetic levitation blood pump system.

[0040] As a preferred embodiment of the present invention, the electromagnet assembly 41 includes a plurality of circumferentially evenly spaced magnetic levitation cores 411. The magnetic levitation cores 411 have a U-shaped cross-section with an opening facing the impeller. The magnetic levitation cores 411 include a base plate 411a, and outer and inner plates 411b and 411c radially outward and inward of the base plate 411a. The ends of the outer and inner plates 411b and 411c are designed to be trapezoidal. The magnetic levitation coil 412 is wound around the base plate 411a. While maintaining the magnetic flux of the entire magnetic flux path, and without triggering the magnetic saturation effect of the magnetic levitation cores 411, appropriately reducing the end face area can increase the magnetic induction intensity passing through the end face, 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 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.

[0041] The suspension magnet assembly 42 includes a radially arranged outer ring magnet 421 and an inner ring magnet 422. The lower end surfaces 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. The upper end surfaces 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, respectively, with a right-angled trapezoidal cross-section. The right-angled trapezoidal cross-sections of the two are arranged in a mirror-symmetrical manner. This design has two purposes: first, the right-angled trapezoidal design has the same purpose as the trapezoidal design at the ends of the outer plate 411b and the inner plate 411c, which is to increase the magnetic induction intensity through the end surfaces of the outer magnetic conductive ring 423 and the inner magnetic conductive ring 424, thereby increasing the magnetic force; second, the purpose of the symmetrical design is to maximize the distance between the upper end surfaces of the two trapezoids, thereby minimizing the degree of bias magnetic field coupling. In summary, when the outer and inner magnetic rings 423 and 424 cooperate with the permanent magnets to form a bias magnetic field system, the right-angled trapezoidal cross-section design can optimize the properties of the magnetic levitation system. The outer and inner magnetic rings 423 and 424 can guide the magnetic field lines and better cooperate with the ends of the magnetic levitation core 411, thereby making the magnetic field distribution in the gap space corresponding to the end face of the magnetic levitation core 411 and the end faces of the outer and inner magnetic rings 423 and 424 more concentrated. This increases the magnetic force and reduces magnetic leakage while maintaining a constant magnetic flux, thereby improving the utilization rate of the magnetic field. In this way, the electromagnet assembly 41 can more efficiently interact with the bias magnetic field when generating a closed-loop control force, thereby improving the suspension efficiency of the entire magnetic levitation system and enabling the blood pump to achieve stable suspension of the impeller 20 with lower energy consumption.

[0042] If the impeller 20 undergoes radial deflection and axial displacement, the magnetic flux of the bias magnetic field generated by the outer annular magnet 421 and the inner annular magnet 422 in the iron core of the electromagnet assembly 41 will change, causing the bias magnetic field force to be larger or smaller relative to the equilibrium position. The magnetic force generated by the bias magnetic field is in an open-loop state and cannot be feedback-adjusted. At this time, it is necessary to actively adjust the current in the magnetic levitation 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 current size and direction of the electromagnet assembly 41, the magnetic force of the bias magnetic field can be precisely compensated to adapt to different radial deflections and axial displacements and control requirements.

[0043] Multiple magnetic levitation cores 411 are fixed to a magnetic levitation PCB 45. The PCB 45 secures the cores 411 together, ensuring they lie on the same circumference. The lower surface of the PCB 45 is equipped with multiple position sensors 46, one positioned between each of two adjacent magnetic levitation cores 411. These position sensors 46 detect the real-time position of the impeller 20. Based on this position signal, the control unit rapidly adjusts the current in the corresponding magnetic levitation coil 412, achieving stable control of the closed-loop control force acting on the impeller 20 in the axial direction.

[0044] The impeller 20 includes an upper plate 21, a lower plate 22 and a blade 23 in the middle. The suspension magnet assembly 42 is embedded in the upper plate 21, the motor rotor magnet 32 ​​is embedded in the inner ring side of the lower plate 22, and the dynamic magnetic ring is embedded in the lower plate and located radially outside the motor rotor magnet.

[0045] The pump housing 10 is divided from top to bottom by a partition into a first sealed chamber A for mounting the electromagnet assembly 41, a blood chamber B for mounting the impeller 20, and a second sealed chamber C for mounting the motor stator assembly 31. A flow guide 13 is positioned in the middle of the partition between the blood chamber B and the second sealed chamber C, projecting toward the interior of the blood chamber B. The motor stator assembly 31 is positioned within the cavity between the flow guide 13 and the second sealed chamber C. The flow guide 13 not only accommodates the static magnetic ring array 43 but also guides blood flow, increasing pump head. The use of a partition to separate the pump chamber into the first sealed chamber A, the blood chamber B, and the second sealed chamber C results in a compact overall structure, fully utilizing space and further reducing the overall volume of the blood pump. The first sealed chamber A and the second sealed chamber C are isolated from the blood chamber B, preventing blood, impurities, and the like from entering the sealed chambers. Only the magnetic field is allowed to pass through, thereby ensuring the stability of the motor stator assembly 31 and the electromagnet assembly 41. The motor rotor magnet 32, suspension magnet assembly 42, and moving magnet ring 44 in impeller 20 are all embedded within impeller 20, preventing direct contact with the blood in blood chamber B, thus preventing blood from corroding the magnets. The space within the cavity of the flow guide 13 is utilized to house the motor stator assembly 31, further reducing the volume and weight of the entire blood pump.

[0046] The motor stator assembly 31 includes a plurality of stator cores 311 spaced apart in the circumferential direction. The cross section of the stator core 311 is in the shape of a " ", and includes a vertical plate 311a and a top plate 311b located on the top of the vertical plate 311a and extending radially outward. The stator coil 312 is wound around the outer periphery of the vertical plate 311a, and the end surface of the top plate 311b is arranged radially corresponding to the rotor magnet assembly 32. The motor rotor magnet 32 ​​is radially magnetized. Figure 2 、 Figure 3 It can be seen that the vertical plate 311a of the stator core 311 and the stator coil 312 wound thereon are not aligned with the motor rotor magnet 32 ​​in the radial direction. Instead, the top plate 311b extending radially outward from the top of the vertical plate 311a is aligned with the motor rotor magnet 32 ​​in the radial direction. The advantage of this arrangement is that, on the one hand, it can ensure that the stator core 311 and the motor rotor magnet 32 ​​can form a specific annular magnetic circuit, thereby improving the pumping efficiency and stability of the blood pump; on the other hand, the coils are arranged axially, with the bent ends facing the motor rotor magnet 32, which can save radial space and optimize the space for reducing the maximum diameter of the pump. At the same time, the attached Figure 2As can be seen, the end surface of top plate 311b is in close contact with the interior of flow guide 13, thus also serving as a fixation and position limiting function, enhancing the stability of the blood pump structure, reducing noise and vibration generated during operation, and improving patient comfort and therapeutic efficacy. The design of the motor stator assembly 31, combining radial stator teeth (top plate 311b) with an axial stator core (vertical plate 311a), eliminates axial force generated by the motor unit 30, reducing the bearing pressure of the axial magnetic levitation. This structure also facilitates efficient space utilization and reduces the size of the blood pump.

[0047] Although part of the motor unit 30 overlaps with the impeller 20 in the axial direction, it is located below the impeller as a whole. That is to say, the motor unit 30 and the magnetic levitation unit 40 are respectively placed at the lower and upper parts of the impeller. This sandwich structure design maximizes the distance between the motor unit 30 and the magnetic levitation unit 40 within a limited space, greatly reducing the magnetic coupling effect between the motor unit 30 and the magnetic levitation unit 40, significantly reducing the control difficulty, improving the stability of the system, further improving the space utilization, reducing the overall volume of the pump body, and at the same time dispersing the heat source, preventing heat accumulation, and reducing the heat dissipation pressure.

[0048] An annular stator yoke 313 is provided at the bottom of the stator core 311, which fixes multiple stator cores 311 into an integrated structure. A main control PCB board 33 is provided in the second sealed chamber C and is located at the periphery of the stator coil 312, which makes rational use of space.

[0049] Furthermore, the static magnetic ring 43 is embedded in the partition between the blood chamber B and the second sealed chamber C, and the dynamic magnetic ring 44 is embedded in the lower plate 22 and located radially outside the motor rotor magnet 32 ​​to avoid it and make rational use of space.

[0050] An inlet tube 15 is provided at the top of the pump housing 10. The inner lumen of the inlet tube 15 communicates with the blood chamber B. The outlet 12 is provided on the sidewall of the blood chamber B. The inlet tube 15 is a slender tube that is implanted into the ventricle at the apex of the heart. A connecting tube is connected to the outlet 12. When the blood pump is activated, blood in the ventricle enters the blood chamber B through the inlet tube 15 and is pumped to the target location through the outlet 12, thereby assisting the heart in pumping blood.

[0051] It should be noted that the above description is limited to some embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the schemes or steps described in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A magnetic levitation blood pump structure, characterized in that: The pump comprises a pump housing (10), an impeller (20) dynamically positioned in a central area of ​​a chamber of the pump housing (10) in a magnetically suspended manner and capable of rotating around a central axis of the pump housing (10) to draw blood from an inlet (11) of the pump housing (10) and discharge blood from an outlet (12); The motor unit (30) is an axial permanent magnet synchronous motor structure, comprising a motor stator assembly (31) and a motor rotor magnet (32) disposed in the impeller (20), and the two are arranged correspondingly in the radial direction. The motor stator assembly (31) provides a rotating magnetic field acting on the motor rotor magnet (32), generating a rotational torque, thereby driving the impeller (20) to rotate; The magnetic suspension unit (40) comprises an electromagnet assembly (41) arranged in the pump housing (10) and a suspension magnet assembly (42) arranged on the impeller (20), the two being arranged in correspondence in the axial direction, and a static magnetic ring (43) arranged in the pump housing (10) and a dynamic magnetic ring (44) arranged in the impeller (20), the two also being arranged in correspondence in the axial direction; the magnetic force between the electromagnet assembly (41) and the suspension magnet assembly (42) and the magnetic force between the static magnetic ring (43) and the dynamic magnetic ring (44) jointly maintain the suspension state of the impeller (20); when the impeller (20) deviates radially, the magnetic forces of the two generate a component force in the radial direction opposite to the radial displacement direction, thereby suppressing the radial deviation of the impeller (20); The magnetic suspension unit (40) and the motor unit (30) are respectively disposed in the central area of ​​the pump casing (10) chamber 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); The electromagnet assembly (41) comprises a plurality of magnetic levitation cores (411) arranged at even intervals in the circumferential direction. The magnetic levitation core (411) is a structure having a U-shaped cross section and an opening facing the impeller, comprising a bottom plate (411a), and an outer plate (411b) and an inner plate (411c) located radially outside and inside the bottom plate (411a). The ends of the outer plate (411b) and the inner plate (411c) are designed to be trapezoidal. The magnetic levitation coil (412) is wound on the bottom plate (411a). The suspension magnet assembly (42) comprises an outer annular magnet (421) and an inner annular magnet (422) arranged radially, the lower end surfaces of the outer plate (411b) and the inner plate (411c) being arranged corresponding to the outer annular magnet (421) and the inner annular magnet (422), respectively, and the upper end surfaces of the outer annular magnet (421) and the inner annular magnet (422) are further provided with an outer magnetic conductive ring (423) and an inner magnetic conductive ring (424) having a right-angled trapezoidal cross section, respectively, and the right-angled trapezoidal cross sections of the two are arranged in mirror symmetry.

2. The magnetic levitation blood pump structure according to claim 1, characterized in that: A plurality of magnetic suspension iron cores (411) are fixed on a magnetic suspension PCB board (45); a plurality of position sensors (46) are provided on the lower surface of the magnetic suspension PCB board (45); and one position sensor (46) is provided between each of two adjacent magnetic suspension iron cores (411).

3. The magnetic levitation blood pump structure according to claim 1, characterized in that: The motor rotor magnet (32) is embedded in the inner ring side of the lower plate (22), and the dynamic magnetic ring (44) is embedded in the lower plate (22) and is located radially outside the motor rotor magnet (32).

4. The magnetic levitation blood pump structure according to claim 3, characterized in that: The inner cavity of the pump housing (10) is divided by a partition into a first sealed chamber (A) for installing the electromagnet assembly (41), a blood chamber (B) for installing the impeller (20), and a second sealed chamber (C) for installing the motor stator assembly (31) from top to bottom. A guide portion (13) protruding toward the inside of the blood chamber (B) is provided in the middle of the partition between the blood chamber (B) and the second sealed chamber (C). The motor stator assembly (31) is provided in the cavity between the guide portion (13) and the second sealed chamber (C).

5. The magnetic levitation blood pump structure according to claim 4, characterized in that: The motor stator assembly (31) includes a plurality of stator cores (311) arranged at intervals in the circumferential direction. The cross section of the stator core (311) is in the shape of a "" and includes a vertical plate (311a) and a top plate (311b) located at the top of the vertical plate (311a) and extending radially outward. The stator coil (312) is wound around the outer periphery of the vertical plate (311a), and the end surface of the top plate (311b) is arranged radially corresponding to the motor rotor magnet (32). The motor rotor magnet (32) is magnetized in a radial manner.

6. The magnetic levitation blood pump structure according to claim 5, characterized in that: An annular stator yoke (313) is provided at the bottom of the stator core (311), and the stator yoke (313) fixes the multiple stator cores (311) into an integrated structure. A main control PCB board (33) is provided in the second sealed chamber (C).

7. The magnetic levitation blood pump structure according to claim 4, characterized in that: The static magnetic ring (43) is embedded in the partition between the blood chamber (B) and the second sealed chamber (C).

8. The magnetic levitation blood pump structure according to claim 3, characterized in that: An inlet pipe (15) is provided on the upper portion of the pump housing (10), the inner cavity of the inlet pipe (15) is communicated with the blood cavity (B), and the outlet (12) is provided on the side wall of the blood cavity (B).

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