Motor control method and device

Abstract

The present application proposes a motor control method and device. The method includes: applying a first suspension current to a first stator and applying a first rotation current to a second stator to suspend and control the impeller to rotate at a first position; when the rotation speed of the impeller reaches a target speed, applying a second rotation current to the first stator and applying a first suspension current and a second rotation current to the second stator. The present application provides two stators, and by using both the first stator and the second stator to control the rotation of the impeller after the impeller reaches the target speed, the power consumption of the second stator can be greatly reduced, thereby prolonging the service life of the motor.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and particularly to a motor control method and device. Background Art

[0002] Pumps used as mechanical circulatory support devices include a pumping mechanism for pumping fluid from one location to another, such as a centrifugal pump, an axial flow pump, or a magnetic levitation pump for pumping blood from the heart to other parts of the body. The pump includes an impeller disposed within a pump housing to push the fluid through the pump housing from the inlet end of the pump to the outlet end, thereby realizing the fluid pumping function. The ventricular assist device is implanted in a patient's body for a long time, and the motor is an important component, and its lifespan directly determines the service life of the ventricular assist device. Summary of the Invention

[0003] Embodiments of this application provide a motor control method and device, which use a first stator and a second stator to simultaneously control the levitating rotation of the impeller, and can extend the lifespan of the motor.

[0004] In a first aspect, an embodiment of this application provides a motor control method, which is applied to a ventricular assist device. The ventricular assist device includes a housing, an impeller disposed within the housing, and a motor for driving the impeller to levitate and rotate. The motor includes a rotor fixedly connected to the impeller and a stator for driving the rotor to levitate and rotate. The stator includes a first stator and a second stator. The method includes:

[0005] Applying a first levitation current to the first stator and a first rotation current to the second stator to levitate and control the impeller to rotate at a first position;

[0006] When the rotation speed of the impeller reaches a target speed, applying a second rotation current to the first stator and applying the first levitation current and the second rotation current to the second stator.

[0007] In a second aspect, a control unit of a ventricular assist device provided by an embodiment of this application. The ventricular assist device includes a housing, an impeller disposed within the housing, and a motor for driving the impeller to levitate and rotate. The motor includes a rotor fixedly connected to the impeller and a stator for driving the rotor to levitate and rotate. The stator includes a first stator and a second stator. The control unit includes one or more processors, and the one or more processors are configured to:

[0008] Applying a first levitation current to the first stator and a first rotation current to the second stator to levitate and control the impeller to rotate at a first position;

[0009] When the rotational speed of the impeller reaches the target rotational speed, a second rotational current is applied to the first stator, and the first suspension current and the second rotational current are applied to the second stator.

[0010] In a third aspect, an embodiment of the present application provides a ventricular assist device, which includes:

[0011] A housing;

[0012] An impeller disposed in the housing;

[0013] A motor that drives the impeller to rotate in a suspended manner, the motor includes a rotor connected to the impeller and a stator that drives the rotor to rotate in a suspended manner, and the stator includes a first stator and a second stator;

[0014] A control unit connected to the motor, and the control unit is configured to execute some or all of the steps described in the method of the first aspect above.

[0015] In a fourth aspect, an embodiment of the present application provides a medical device, which includes a processor, a memory, a communication interface, and one or more programs. The one or more programs are stored in the memory and are configured to be executed by the processor. The programs include instructions for executing some or all of the steps described in the method of the first aspect above.

[0016] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium that stores a computer program for electronic data exchange. The computer program causes a computer to execute some or all of the steps described in the method of the first aspect above.

[0017] In a sixth aspect, an embodiment of the present application provides a computer program product. The computer program product includes a non-transitory computer-readable storage medium storing a computer program. The computer program is operable to cause a computer to execute some or all of the steps described in the method of the first aspect of the embodiments of the present application. The computer program product can be a software installation package.

[0018] The technical solution provided by the present application applies a first suspension current to the first stator and a first rotational current to the second stator to control the impeller to rotate at a first position in a suspended manner; when the rotational speed of the impeller reaches the target rotational speed, a second rotational current is applied to the first stator, and the first suspension current and the second rotational current are applied to the second stator. The present application provides two stators, and by using both the first stator and the second stator to control the rotation of the impeller after the impeller reaches the target rotational speed, the power consumption of the second stator can be greatly reduced, thereby prolonging the life of the motor. Description of the Drawings

[0019] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 is a schematic structural diagram of a ventricular assist device provided by an embodiment of the present application;

[0021] Figure 2 is a partial explosion schematic diagram of a ventricular assist device provided by an embodiment of the present application;

[0022] Figure 3 is a schematic flowchart of a motor control method provided by an embodiment of the present application;

[0023] Figure 4 is a schematic diagram showing the coincidence of the stator zero line and the rotor zero line provided by an embodiment of the present application;

[0024] Figure 5 is a schematic structural diagram of a medical device provided by an embodiment of the present application. Detailed implementation manners

[0025] For those in the technical field to better understand the technical solutions of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the description of the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope protected by the present application.

[0026] Terms such as "first" and "second" in the specification, claims and above-mentioned drawings of the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, software, product or device that includes a series of steps or units is not limited to the listed steps or units, but also includes unlisted steps or units, or also includes other steps or units inherent to these processes, methods, products or devices.

[0027] References to "embodiments" in this specification mean that particular features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0028] The pump involved in the present application can be a ventricular assist device in a medical auxiliary device. The pump can be an implantable ventricular assist device (Ventricular Assist Devices, VAD), and the VAD can be attached to the left ventricle, or the right ventricle, or both ventricles of the heart. The VAD can further include a magnetic levitation pump capable of delivering the entire output according to the pulmonary circulation or blood circulation to the left ventricle.

[0029] The embodiments of the present application are described and illustrated by taking a centrifugal magnetic levitation pump as an example.

[0030] The ventricular assist device can be attached to the heart via a ventricular connection component (such as a top ring, ventricular cuff, ventricular sleeve). The ventricular connection component can be sutured to the heart and connected to the ventricular assist device. The other end of the ventricular assist device can be connected to the ascending aorta via an outlet tube and / or an artificial blood vessel connected to the outlet tube, so that the ventricular assist device can effectively transfer blood from the weakened ventricle and push it into the aorta, thereby circulating to the remaining part of the patient's vascular system and providing ventricular assist function for the patient.

[0031] Please refer to Figure 1 , Figure 1 FIG. 16 is a schematic structural diagram of a ventricular assist device 100 provided by an embodiment of the present application, particularly relating to a centrifugal magnetic levitation ventricular assist device. The ventricular assist device 100 includes a housing assembly, an impeller 20 disposed in the housing assembly, and a motor 10 that drives the impeller 20 to rotate in a suspended manner.

[0032] The housing assembly has an inlet 14, an outlet 15, and a first chamber 30 and a second chamber 40 that are spaced apart. Both the inlet 14 and the outlet 15 communicate with the first chamber 30. In the illustrated embodiment, the central axis of the inlet 14 and the central axis of the outlet 15 are perpendicular; the first chamber 30 and the second chamber 40 are arranged along the central axis of the inlet 14. Among them, the first chamber 30 has a first chamber wall 31 and a second chamber wall 32 that are spaced apart and opposite along the central axis of the inlet 14. The second chamber 40 is disposed adjacent to the second chamber wall 32.

[0033] The impeller 20 is rotatably disposed within the first chamber 30. Among them, the impeller 20 is located between the first chamber wall 31 and the second chamber wall 32. Specifically, when the impeller 20 operates stably, the rotation axis 21 of the impeller 20 coincides with the central axis of the liquid inlet 14. Through the rotation of the impeller 20, external liquid (such as blood) enters the first chamber 30 from the liquid inlet 14 and flows out from the liquid outlet 15.

[0034] The motor 10 includes a stator 11 and a rotor 13. The stator 11 is disposed within the second chamber 40, and the rotor 13 is disposed within the first chamber 30. The rotor 13 is fixedly connected to the impeller 20. Among them, the stator 11 can drive the rotor 13 to rotate in suspension, and the impeller 20 can rotate in suspension along with the rotor 13. Specifically, the rotor 13 is disposed within the impeller 20. The suspended rotation of the impeller 20 means that the impeller 20 does not contact the chamber wall of the first chamber 30 during rotation.

[0035] Exemplarily, the motor 10 can be a three-phase brushless direct current (BLDC) motor. The stator 11 has three windings controlled by different corresponding phases U, V, W of the power input controlled by a three-phase motor. The motor 10 may further include an inverter circuit, which can be used to convert the DC input into a three-phase output. Exemplarily, the ventricular assist device 100 can receive a three-phase AC input.

[0036] In Figure 2 In the illustrated embodiment, the stator 11 includes a first stator 110 and a second stator 120, and both the first stator 110 and the second stator 120 are generally annular. The first stator 110 includes 3N first winding units, and the 3N first winding units are arranged at equal intervals along the first circle. The second stator 120 includes 3N second winding units, and the 3N second winding units are arranged at equal intervals along the second circle. Among them, the second circle and the first circle are concentric, and the diameter of the first circle is smaller than the diameter of the second circle. In other words, the first stator 110 and the second stator 120 are coaxially arranged, and the first stator 110 is located inside the second stator 120. Specifically, each first winding unit and each second winding unit each include a stator tooth and a stator coil disposed on the stator tooth.

[0037] The rotor 13 includes a first rotor 130 and a second rotor 140, and both the first rotor 130 and the second rotor 140 are fixedly connected to the impeller 20. Specifically, both the first rotor 130 and the second rotor 140 are disposed inside the impeller 20. Both the first rotor 130 and the second rotor 140 are circular rings, and the first rotor 130 and the second rotor 140 are concentric and coaxial, and the central axes of the first rotor 130 and the second rotor 140 coincide with the rotation axis 21 of the impeller 20. The inner diameter of the second rotor 140 is greater than the outer diameter of the first rotor 130. Along the central axis direction of the first rotor 130 or the second rotor 140, the position of the first rotor 130 corresponds to the position of the first stator 110 (i.e., the first rotor 130 and the first stator 110 are axially aligned along the axis of the first stator 110), and the first stator 110 can drive the first rotor 130 to rotate and levitate, that is, the first stator 110 and the first rotor 130 together form a first motor; the position of the second stator 120 corresponds to the position of the second rotor 140 (i.e., the second rotor 140 and the second stator 120 are axially aligned along the axis of the second stator 120), and the second stator 120 can drive the second rotor 140 to rotate and levitate, that is, the second stator 120 and the second rotor 140 together form a second motor. The first motor and the second motor can be independently controlled. In some embodiments, the first motor is used to drive the levitation and / or rotation of the impeller 20, and the second motor is also used to drive the levitation and / or rotation of the impeller 20. For example, the first motor is used to drive the impeller 20 to levitate, and the second motor is used to drive the impeller 20 to rotate. Or, the first motor is used to drive the levitation and rotation of the impeller 20, and the second motor is used to drive the impeller 20 to rotate. By way of example, the functions of the first motor and the second motor can be switched with each other. At certain moments, the first motor is used to drive the impeller 20 to levitate, and the second motor is used to drive the impeller 20 to rotate, and at other moments, the first motor is used to drive the impeller to rotate, and the second motor is used to drive the impeller to levitate. Among them, since both the first rotor 130 and the second rotor 140 are fixedly connected to the impeller 20, the first rotor 130, the second rotor 140 and the impeller 20 move synchronously. The magnetic pole distribution angles of the first motor and the second motor, and the distribution angles of the stator core and the coil are all the same, so as to realize the synchronous control of the first motor and the second motor.

[0038] In the illustrated embodiment, the outer peripheral wall of the first rotor 130 is fixedly connected to the inner peripheral wall of the second rotor 140 to reduce the magnetic pole angle deviation of the impeller 20. By way of example, the first rotor 130 and the second rotor 140 can be fixedly connected by means of gluing. In other embodiments, the outer peripheral wall of the first rotor 130 and the inner peripheral wall of the second rotor 140 are opposite and spaced apart. Among them, the outer peripheral wall of the first rotor 130 is the side wall of the first rotor 130 facing away from the central axis of the first rotor 130; the inner peripheral wall of the second rotor 140 is the side wall of the second rotor 140 facing the central axis of the second rotor 140.

[0039] Specifically, both the first rotor 130 and the second rotor 140 include a plurality of magnetic blocks. The plurality of magnetic blocks of the first rotor 130 are spliced into a first ring structure, and the plurality of magnetic blocks of the second rotor 140 are spliced into a second ring structure. Each magnetic block is generally in a fan shape. In some embodiments, the magnetization direction of each magnetic block of the first rotor 130 is the same as the axial direction of the first rotor 130, and the magnetic poles of adjacent magnetic blocks are opposite; in some embodiments, the plurality of magnetic blocks of the first rotor 130 are arranged in the manner of a Halbach array, that is, the first rotor 130 is a Halbach array magnet. The arrangement of the magnetic blocks of the second rotor 140 is substantially the same as that of the magnetic blocks of the first rotor 130, and will not be described in detail.

[0040] In some embodiments, the positions of the plurality of magnetic blocks of the first rotor 130 are respectively set in one-to-one correspondence with the positions of the plurality of magnetic blocks of the second rotor 140, that is, each magnetic block of the first rotor 130 corresponds to the position of a magnetic block of the second rotor 140 to form a plurality of magnet block groups with corresponding positions. In each magnet block group with corresponding positions, the magnetization directions of the magnetic blocks of the first rotor 130 and the magnetic blocks of the second rotor 140 are the same, the magnetic blocks of the first rotor 130 and the magnetic blocks of the second rotor 140 are arranged along the radial direction of the first rotor 130 and / or the second rotor 140, and the outer peripheral wall of the magnetic block of the first rotor 130 is opposite to the inner peripheral wall of the magnetic block of the second rotor 140; and in each magnet block group with corresponding positions, the central angle corresponding to the fan ring where the magnetic block of the first rotor 130 is located is equal to the central angle corresponding to the fan ring where the magnetic block of the second rotor 140 with the corresponding position is located. In some embodiments, in each magnet block group with corresponding positions, the outer peripheral wall of the magnetic block of the first rotor 130 is fixedly connected or in contact with the inner peripheral wall of the magnetic block of the second rotor 140, that is, the outer peripheral walls of the first rotor 130 and the second rotor 140 are fixedly connected or in contact. In some embodiments, in each magnet block group with corresponding positions, the magnetic blocks of the first rotor 130 and the magnetic blocks of the second rotor 140 are arranged at intervals along the radial direction of the second rotor 140. Wherein, the outer peripheral wall of the magnetic block of the first rotor 130 is the side wall of the magnetic block facing away from the central axis of the first rotor 130; the inner peripheral wall of the magnetic block of the second rotor 140 is the side wall of the magnetic block facing the central axis of the second rotor 140.

[0041] Wherein, each magnetic block of the first rotor 130 has a center line, and the center line is perpendicular to and intersects the central axis of the first rotor 130; each magnetic block of the second rotor 140 also has a center line, and the center line of each magnetic block of the second rotor 140 is perpendicular to and intersects the central axis of the second rotor 140. In each magnet block group with corresponding positions, the center lines of the magnetic blocks of the first rotor 130 and the center lines of the magnetic blocks of the second rotor 140 coincide.

[0042] In some other embodiments, the first stator 110 and the second stator 120 may also share a rotor 13. That is, along the central axis direction of the rotor 13, the position of the rotor 13 corresponds to both the first stator 110 and the second stator 120, that is, the rotor 13 is aligned with both the first stator 110 and the second stator 120 in the axial direction of the first stator 110 and / or the second stator 120. At this time, the rotor 13 has a relatively large radial width. The first stator 110 can drive the rotor 13 to levitate and rotate, and the second stator 120 can also drive the rotor 13 to levitate and rotate. Among them, the first stator 110 and the second stator 120 are independently controlled. At this time, the rotor 13 includes a plurality of magnetic blocks, and the plurality of magnetic blocks are spliced into an annular structure, and at least part of the magnetic blocks are magnetized along the axial direction of the rotor 13; and along the circumferential direction of the rotor 13, the magnetic poles of adjacent axially magnetized magnetic blocks are opposite. In some embodiments, the magnetization direction of each magnetic block of the rotor 13 is the same as the axial direction of the rotor 13, and the magnetic poles of adjacent magnetic blocks are opposite; in some embodiments, the plurality of magnetic blocks of the rotor 13 are arranged in the form of a Halbach array, that is, the rotor 13 is a Halbach array magnet. Each magnetic block in the rotor 13 has a center line, and the center line is perpendicular to and intersects the central axis of the rotor 13.

[0043] The impeller 20 moves axially relative to the housing assembly along the rotation axis 21. During rotation, the impeller 20 is levitated within the housing assembly by a contactless bearing, such as a magnetic bearing, which can generate a magnetic levitation system. For example, in some embodiments, magnets (not shown in the figure) are respectively provided in the housing assembly and the impeller 20. The magnet in the housing assembly and the magnet in the impeller 20 together constitute a magnetic bearing. The force generated by the magnetic bearing on the impeller 20 and the magnetic force generated between the stator 11 and the rotor 13 act on the impeller 20 together, so that the impeller 20 is levitated in the first chamber 30 in a state of magnetic force balance, thereby realizing the motion state of the impeller 20 levitating and rotating. The control unit 33 can control the levitation attitude and position of the impeller 20 by controlling the magnetic force between the stator 11 and the rotor 13. At the same time, in the direction perpendicular to the rotation axis 21, a torsional force is generated by using the attraction and repulsion between the stator 11 and the rotor 13, and the torsional force causes the impeller 20 to rotate in this direction. Among them, when the impeller 20 rotates at a preset speed, the attraction or thrust between the stator 11 and the rotor 13 causes the impeller 20 in the first chamber 30 to levitate and rotate in the first chamber 30.

[0044] The ventricular assist device 100 further includes a control unit 33 and a sensor 50. The control unit 33 is electrically connected to the stator 11, and the sensor 50 is electrically connected to the control unit 33. The sensor 50 is used to detect the magnetic pole angle and the suspension height of the impeller 20. The control unit 33 is used to receive the detection results of the sensor 50 and can control the rotation speed and the suspension height of the impeller 20 through the motor 10 according to the detection results. Specifically, the suspension height of the impeller 20 is the distance of the impeller 20 relative to the second cavity wall 32.

[0045] Further, the control unit 33 is used to monitor and control the startup and subsequent operation of the motor 10, including implementing the Field-Oriented Control (FOC) method. The control unit 33 can be a module independent of the stator 11 or can be built into the stator 11. The control unit 33 includes hardware and software for controlling various aspects of the operation of the motor 10. The control unit 33 can be coupled to the motor 10 through an interface to collect at least one data of the motor 10. The at least one data can include the measured current flowing through the stator 11, the data measured by the sensor 50, the motor speed, the pressure difference across the pump, the flow pulsatility, the fluid flow rate, and so on.

[0046] The sensor 50 includes 3N first position sensors 51 and 3N second position sensors 52. Each first position sensor 51 is disposed between two adjacent first winding units. The first position sensor 51 is used to measure the suspension height and the magnetic pole angle of the first rotor 130 corresponding to the first winding unit. Each second position sensor 52 is disposed between two adjacent second winding units. The second position sensor 52 is used to measure the suspension height and the magnetic pole angle of the second rotor 140 corresponding to the second winding unit. Specifically, each position sensor is disposed opposite to the path of the rotor 13 on the impeller 20. When the impeller 20 rotates and the S pole and N pole of the rotor 13 alternately pass near the position sensor, the signal level representing the magnetic flux intensity output by the position sensor changes in a wave shape (such as a square wave, a sine wave). Therefore, by detecting the time change of the output signal of the position sensor, the positional relationship of the first rotor 130 relative to the first stator 110 and the positional relationship of the second rotor 140 relative to the second stator 120 can be detected, and thus the rotation speed and the suspension height of the impeller 20 can be calculated.

[0047] Exemplarily, the first position sensor 51 and the second position sensor 52 can be Hall sensors, eddy current sensors, distance sensors, etc.

[0048] The first stator 110 and the second stator 120 are generally annular. Every three adjacent first winding units among the 3N first winding units form a first three-phase winding, and every three adjacent second winding units among the 3N second winding units form a second three-phase winding. The positions of the first three-phase windings respectively correspond one-to-one to the positions of the second three-phase windings. For example, the U-phase of the first three-phase winding unit is radially aligned with the U-phase of the second three-phase winding unit along the first stator 110 and / or the second stator 120, the V-phase of the first three-phase winding unit is radially aligned with the V-phase of the second three-phase winding unit along the first stator 110 and / or the second stator 120, and the W-phase of the first three-phase winding unit is radially aligned with the W-phase of the second three-phase winding unit along the first stator 110 and / or the second stator 120. Exemplarily, the first rotor 130 and the second rotor 140 are both fixedly connected to the impeller 20, so that the first rotor 130, the second rotor 140, and the impeller 20 move synchronously. The control unit 33 can control the magnitude and phase of the current flowing through the stator coils in the first stator 110 and / or the second stator 120, and can control the pole angle and suspension height of the entire rotor 13; and, the control unit 33 can control the suspension height of the rotor 13 to make the impeller 20 suspend at a desired axial position relative to the stator 11.

[0049] Wherein, the winding units in the first three-phase winding and the second three-phase winding are respectively three windings controlled by different corresponding phases U, V, and W of the voltage input controlled by a three-phase motor. The control unit 33 can control the application of current to the first three-phase winding to control the suspension and / or rotation of the first rotor 130, thereby controlling the suspension and / or rotation of the impeller 20; the control unit 33 can control the application of current to the second three-phase winding to control the suspension and / or rotation of the second rotor 140, thereby controlling the suspension and / or rotation of the impeller 20.

[0050] Combined with the above description, the present application will be described from the perspective of method examples below.

[0051] Please refer to Figure 3 , Figure 3 which is a schematic flowchart of a motor control method provided by an embodiment of the present application and is applied to the ventricular assist device 100 as shown in Figure 1 - Figure 2 . As shown in Figure 3 , the method includes the following steps.

[0052] S310: Apply a first suspension current to the first stator and a first rotation current to the second stator to control the suspension of the impeller at a first position and rotate.

[0053] After receiving the start command, the control unit 33 first applies a first levitation current to the first stator 110 to levitate the impeller 20 to the first position. After the impeller 20 is levitated to the first position, the control unit 33 can control the rotation of the impeller 20 through the second stator 120. The control unit 33 applies a first rotation current to the first stator 110 to control the impeller 20 to rotate at the first position, so that the impeller 20 is non-contact with the housing assembly when rotating, thereby reducing or avoiding the friction between the impeller 20 and the housing assembly.

[0054] Specifically, the control unit 33 applies a first levitation current to the first three-phase winding in the first stator 110, so that the winding unit in the first three-phase winding facing the N-pole magnet in the first rotor 130 shows an N-pole, or the winding unit in the first three-phase winding facing the S-pole magnet in the first rotor 130 shows an S-pole, so that an axial magnetic thrust is generated between the first stator 110 and the first rotor 130. The axial magnetic thrust makes the impeller 20 move axially, thereby realizing the levitation control of the impeller 20. After the impeller 20 is levitated to the first position, the control unit 33 supplies a three-phase alternating current to the second three-phase winding in the second stator 120, and each phase of the alternating current differs by 120 degrees. The second three-phase winding is controlled by controlling the application of alternating current to the winding units of phases U, V, and W to generate a torsional force relative to the second rotor 140, and this torsional force makes the driving impeller 20 rotate along the rotation axis 21 of the impeller.

[0055] Among them, the first position is within a preset levitation range, and the preset levitation range is near the center of the first chamber 30. Exemplarily, the preset levitation range is 0.05 mm - 0.5 mm.

[0056] Further, if before levitating the impeller 20, the projection of the zero line O of the rotor 13 does not coincide with the projection of the zero line P of the stator 11 in the target plane, or there is no winding unit in the first stator 110 facing the magnet in the first rotor 130, at this time, there is no current in the stator coil of the stator 11, and an effective axial magnetic force cannot be generated with the rotor 13. The control unit 33 can apply a rotation current to the first stator 110 and / or the second stator 120 to generate a magnetic suction force. For example, the control unit 33 applies a current to the U-phase winding unit of the first three-phase winding and the U-phase winding unit of the second three-phase winding, so that the U-phase winding unit in the first three-phase winding unit and the U-phase winding unit in the second three-phase winding show an S-pole magnetism, generating a magnetic suction force with the N-pole magnetic block of the rotor 13. This magnetic suction force moves the rotor 13 along its circumferential direction, so that the projection of the zero line P of the stator 11 coincides with the projection of the zero line O of the rotor 13 in the target plane.

[0057] As Figure 4As shown, the rotor 13 includes a first rotor 130 and a second rotor 140. Both the first rotor 130 and the second rotor 140 include 8 magnetic blocks. The rotor 13 rotates counterclockwise at a rotational speed w. The zero line O of the rotor 13 is the center line of the magnetic block group corresponding to any position where the magnetic pole on the side of the first rotor 130 and the second rotor 140 close to the stator 11 is N. Both the first stator 110 and the second stator 120 include 6 winding units. Three adjacent U-phase winding units, V-phase winding units, and W-phase winding units in the first stator 110 form a first three-phase winding. Three adjacent U-phase winding units, V-phase winding units, and W-phase winding units in the second stator 120 form a second three-phase winding. The zero line P of the stator 11 is the center line of the U-phase winding units in the first three-phase winding and the second three-phase winding, that is, the first-phase winding unit is the U-phase winding unit. The projection of the center line of the magnetic block group or magnetic block where the magnetic pole on the side of the rotor 13 close to the stator 11 is N coincides with the projection of the center line of the U-phase winding units of the first three-phase winding and the U-phase winding units of the second three-phase winding on the target plane. The target plane is a plane perpendicular to the central axis of the first stator 110 and / or the second stator 120, such as a plane parallel to the second cavity wall 32 or a plane parallel to the side of the impeller 20 close to the stator 11. After the projection of the zero line P of the stator 11 coincides with the projection of the zero line O of the rotor 13 on the target plane, the control unit 33 applies a first suspension current to the first stator 110 and a first rotation current to the second stator 120 to suspend and control the impeller 20 to rotate at the first position.

[0058] The sensor 50 can Figure 4 mark the positional relationship between the rotor 13 and the stator 11 in it as the initial zero position of the rotor 13. Subsequently, the control unit 33 can calculate the magnetic pole angle of the current rotor 13 according to the position change of the rotor 13 relative to the initial zero position.

[0059] It should be noted that the zero line O of the rotor 13 can also be the center line of the magnetic block group or magnetic block where any magnetic pole on the side of the first rotor 130 and the second rotor 140 close to the stator 11 is S. The zero line P of the stator 11 can also be the center line of the V-phase winding units or the W-phase winding units in the first three-phase winding and the second three-phase winding, that is, the first-phase winding unit can be the V-phase winding unit or the W-phase winding unit. The center line of any winding unit in the first stator 110 and the second stator 120 is perpendicular to and intersects the central axis of the stator 11.

[0060] S320. When the rotational speed of the impeller reaches the target rotational speed, apply a second rotation current to the first stator and apply the first suspension current and the second rotation current to the second stator.

[0061] Among them, the target rotational speed is within the rotational speed range allowed during the normal operation of the ventricular assist device 100, and this rotational speed range is 2200 RPM to 4300 RPM. When applying a first rotational current to the second stator 120 to rotate the impeller 20 at the target rotational speed, the second stator 120 requires more power consumption, and thus generates more heat. The heat will be transferred to the impeller 20 and the housing assembly, causing the temperature inside the ventricular assist device 100 to rise. Excessive temperature will increase the risks of thrombosis and hemolysis, and also affect the use of the stator 11, thereby affecting user safety and the service life of the motor 10.

[0062] Therefore, when the rotational speed of the impeller 20 reaches the target rotational speed, the control unit 33 also applies a rotational current to the first stator 110, so that the rotational current applied to the second stator 120 can be reduced, thereby reducing the power consumption generated by the second stator 120 and further extending the service life of the second stator 120.

[0063] Optionally, when the rotational speed of the impeller reaches the target rotational speed, applying a second rotational current to the first stator and applying the first suspension current and the second rotational current to the second stator includes: when the rotational speed of the impeller reaches the target rotational speed, stopping applying the first suspension current to the first stator, and simultaneously applying the first suspension current and the first rotational current to the second stator; when the rotor rotates to the initial zero position, applying the second rotational current to the first stator, and applying the second rotational current and the first suspension current to the second stator.

[0064] In the present application, when the rotational speed of the impeller 20 reaches the target rotational speed, the control unit 33 can control the application of a rotational current to the first stator 110 to use the first stator 110 and the second stator 120 to simultaneously drive the impeller 20 to rotate, reducing the power consumption generated by the second stator 120.

[0065] Since directly applying the second rotational current to the first stator 110 may cause the motor 10 to operate unstably, the control unit 33 first stops applying the first suspension current to the first stator 110, and simultaneously applies this first suspension current to the second stator 120, and the second stator 120 controls the suspension and rotation of the impeller 20. When the rotor 13 rotates to make the projection of the zero line O of the rotor coincide with the projection line P of the stator on the target plane, that is, when the first rotor 130 is in the initial zero position, the control unit 33 applies the second rotational current to the first stator 110, and simultaneously reduces the rotational current applied to the second stator 120, which can avoid the deviation of the rotational control of the rotor 13 caused by the non-synchronization between the driving of the first rotor 130 and the second rotor 140. Specifically, continuously applying the first suspension current to the second stator 120, and also applying the second rotational current to the second stator 120, to stabilize the impeller 20 at the first position and rotate at the target rotational speed.

[0066] Among them, the magnitude of the second rotational current is 1 / 2 of the magnitude of the first rotational current. The impeller 20 keeps rotating at the target speed at the first position, and the torsional force driving the rotation of the impeller 20 remains unchanged. Therefore, when the rotation of the impeller 20 driven by applying a rotational current to the second stator 120 is changed to the rotation of the impeller 20 driven by applying rotational currents to the first stator 110 and the second stator 120 simultaneously, the rotational current applied by the control unit 33 will not change, that is, the sum of the rotational current applied by the control unit 33 to the first stator 110 and the rotational current applied to the second stator 120 is equal to the first rotational current. In order to minimize the heat generated by the motor 10 in this application, the rotational currents applied by the control unit 33 to the first stator 110 and the second stator 120 are the same. That is to say, the control unit 33 simultaneously applies the second rotational current to the first stator 110 and the second stator 120, and this second rotational current is 1 / 2 of the first rotational current, so that the sum of the torque forces generated by the first stator 110 on the first rotor 130 and the torque forces generated by the second stator 120 on the second rotor 140 can make the impeller 20 rotate at the target speed.

[0067] In another possible example, when the rotational speed of the impeller 20 reaches the target speed and the rotor 13 is at the initial zero position, the control unit 33 directly applies the second rotational current to the first stator 110 again, and at the same time reduces the rotational current applied to the second stator 120. By applying the second rotational current to the second stator 120, the first stator 110 provides the axial suspension force and half of the torque force, and the second stator 120 provides the other half of the torque force to maintain the impeller 20 at the first position and rotate at the target speed, thereby reducing the power consumption of the second stator 120 and prolonging the service life of the motor 10.

[0068] Optionally, the method further includes: when it is detected that the impeller is offset, applying a second suspension current to the first stator to keep the impeller at the first position.

[0069] In the present application, the second stator 120 provides an axial suspension force to the impeller 20 to stably suspend the impeller 20 at the first position. However, during the operation of the ventricular assist device 100, the impeller 20 may be disturbed by the outside world, resulting in the offset or tilt of the impeller. The tilt of the impeller 20 will make the operation of the impeller 20 unstable, and even contact with the housing assembly, causing surface damage to the inner wall of the impeller 20 and the housing assembly, resulting in fluid retention or thrombosis. The offset of the impeller 20 will reduce the gap between the impeller 20 and the first cavity wall 31 or the second cavity wall 32, increasing the risk of fluid retention and thrombosis formation. Therefore, the control unit 33 monitors in real time whether the impeller 20 is offset or tilted according to the signals fed back by the first position sensor 51 and the second position sensor 52. When the impeller 20 is offset or tilted, a second suspension current is additionally applied to the first stator 110 to generate an axial force opposite to the offset or tilt, adjust the suspension attitude of the impeller 20, and stably suspend the impeller 20 at the first position, improving the operation stability of the impeller 20.

[0070] Exemplarily, if the control unit 33 applies a first suspension current to the first stator 110 to drive the suspension of the impeller 20, when monitoring whether the impeller 20 is offset or tilted, the control unit 33 additionally applies a second suspension current to the second stator 120. The suspension attitude of the impeller 20 is adjusted by the second suspension current to stably suspend the impeller 20 at the first position.

[0071] Wherein, the magnitude and direction of the second suspension current are respectively determined by the offset amount and the offset direction of the impeller 20.

[0072] Specifically, if the impeller 20 is offset or tilted towards the first cavity wall 31, an axial force towards the second cavity wall 32 needs to be additionally provided to the rotor 13; if the impeller 20 is offset or tilted towards the second cavity wall 32, an axial force towards the first cavity wall 31 needs to be additionally provided to the rotor 13. The axial force towards the first cavity wall 31 can be the magnetic thrust generated between the first winding unit of the first stator 110 and the magnet in the first rotor 130 opposite thereto; the axial force towards the second cavity wall 32 can be the magnetic suction generated between the first winding unit of the first stator 110 and the magnet in the first rotor 130 opposite thereto.

[0073] Among them, the control unit 33 applies a first suspension current to the second stator 120 to suspend the impeller 20 to the first position. Specifically, the control unit 33 applies the first suspension current to the second three-phase winding in the second stator 120, so that the winding unit in the second three-phase winding opposite to the N-pole magnet in the second rotor 140 shows an N-pole, or the winding unit in the second three-phase winding opposite to the S-pole magnet in the second rotor 140 shows an S-pole, so that an axial magnetic thrust is generated between the second stator 120 and the second rotor 140. The axial magnetic thrust makes the impeller 20 move axially, thereby realizing the suspension control of the impeller 20.

[0074] Since the placement of the magnets in the first rotor 130 is the same as that in the second rotor 140, and the placement of the winding units in the first stator 110 and the second stator 120 is also the same, the magnets in the first rotor 130 opposite to the winding units in the first stator 110 and the magnets in the second rotor 140 opposite to the winding units in the second stator 120 are in the same magnet group or are the same magnet. When magnetic thrust needs to be provided, the magnetic poles shown by the first winding unit in the first stator 110 opposite to the magnet in the first rotor 130 are the same as the magnetic poles shown by the second winding unit in the second stator 120 opposite to the magnet in the second rotor 140; when magnetic suction needs to be provided, the magnetic poles shown by the first winding unit in the first stator 110 opposite to the magnet in the first rotor 130 are opposite to the magnetic poles shown by the second winding unit in the second stator 120 opposite to the magnet in the second rotor 140. That is to say, when an axial force towards the first cavity wall 31 needs to be provided, the direction of the first suspension current applied by the control unit 33 to the second stator 120 is the same as the direction of the second suspension current applied to the first stator 110. When an axial force towards the second cavity wall 32 needs to be provided, the direction of the first suspension current applied by the control unit 33 to the second stator 120 is opposite to the direction of the second suspension current applied to the first stator 110.

[0075] Furthermore, the greater the offset distance or skew angle of the impeller 20, the greater the required magnetic thrust or magnetic suction, and thus the greater the magnitude of the second suspension current. Among them, the offset distance is the axial distance of the impeller 20 relative to the first position, and the tilt angle is the angle between the plane of the impeller 20 facing the first cavity wall 31 and the target plane.

[0076] It can be seen that the present application proposes a motor control method. The technical solution provided by the present application applies a first suspension current to the first stator and a first rotation current to the second stator to suspend and control the impeller to rotate at a first position. When the rotation speed of the impeller reaches the target speed, a second rotation current is applied to the first stator, and the first suspension current and the second rotation current are applied to the second stator. The present application provides two stators, and by using both the first stator and the second stator to control the rotation of the impeller after the impeller reaches the target speed, the power consumption of the second stator can be greatly reduced, thereby extending the service life of the motor.

[0077] The above mainly introduces the solution of the embodiment of the present application from the perspective of the execution process on the method side. It can be understood that in order for the network device to implement the above functions, it includes the corresponding hardware structure and / or software module for executing each function. Those skilled in the art should easily realize that the present application can be implemented in the form of hardware or a combination of hardware and computer software in combination with the units and algorithm steps of each example described in the embodiments provided herein. Whether a certain function is executed in the manner of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0078] Exemplarily, the present application further provides a control unit for a ventricular assist device. The ventricular assist device includes a housing, an impeller disposed in the housing, a motor for driving the impeller to rotate in suspension. The motor includes a rotor embedded in the impeller and a stator for driving the rotor to rotate in suspension. The stator includes a first stator and a second stator. The control unit includes one or more processors, and the one or more processors are configured to:

[0079] Apply a first suspension current to the first stator and a first rotation current to the second stator to suspend and control the impeller to rotate at a first position;

[0080] When the rotation speed of the impeller reaches the target speed, apply a second rotation current to the first stator, and apply the first suspension current and the second rotation current to the second stator.

[0081] Exemplarily, the present application further provides a ventricular assist device, and the ventricular assist device includes:

[0082] A housing;

[0083] An impeller disposed in the housing;

[0084] A motor for driving the impeller to rotate in suspension, the motor including a rotor embedded in the impeller and a stator for driving the rotor to rotate in suspension, the stator including a first stator and a second stator;

[0085] The control unit connected to the motor, the control unit being configured to execute some or all of the steps described in the above-mentioned method.

[0086] Exemplarily, the present application further provides a medical device, the medical device including the above-mentioned control unit or a ventricular assist device.

[0087] Wherein, the control unit of each of the above solutions has the function of implementing the corresponding steps performed by the medical device in the above-mentioned method; the function can be implemented by hardware or by hardware executing corresponding software.

[0088] In an embodiment of the present application, the control unit may also be a chip or a chip system, for example: a system on chip (SoC).

[0089] Please refer to Figure 5 , Figure 5 FIG. is a schematic structural diagram of a medical device provided by an embodiment of the present application, the medical device including: one or more processors, one or more memories, one or more communication interfaces, and one or more programs; the one or more programs are stored in the memory and are configured to be executed by the one or more processors.

[0090] The above program includes instructions for performing the following steps:

[0091] Applying a first suspension current to the first stator and a first rotation current to the second stator to control the impeller to rotate at a first position in suspension;

[0092] When the rotational speed of the impeller reaches the target rotational speed, applying a second rotation current to the first stator and applying the first suspension current and the second rotation current to the second stator.

[0093] Wherein, all relevant contents of each scenario involved in the above method embodiment can be cited in the function description of the corresponding functional module, and will not be elaborated herein.

[0094] It should be understood that the above memory may include a read-only memory and a random access memory, and provide instructions and data to the processor. A part of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type.

[0095] In the embodiments of the present application, the processor of the above device may be a Central Processing Unit (CPU), and the processor may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0096] It should be understood that the "at least one" involved in the embodiments of the present application refers to one or more, and the "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple.

[0097] Also, unless otherwise stated, the ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects and are not used to limit the order, timing, priority, or importance of multiple objects. For example, the first information and the second information are only used to distinguish different information, rather than indicating differences in the content, priority, sending order, or importance of these two pieces of information, etc.

[0098] In the implementation process, each step of the above method can be completed by the integrated logic circuit in the hardware of the processor or the instructions in software form. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed and completed by the hardware processor, or executed and completed by the combination of the hardware and software units in the processor. The software unit may be located in a mature storage medium in the art such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers, etc. This storage medium is located in the memory, and the processor executes the instructions in the memory and combines its hardware to complete the steps of the above method. To avoid repetition, it will not be described in detail here.

[0099] The embodiments of the present application also provide a computer storage medium, where the computer storage medium stores a computer program for electronic data exchange, and the computer program enables the computer to execute some or all of the steps of any method recorded in the above method embodiments.

[0100] The embodiments of the present application also provide a computer program product. The computer program product includes a non-transitory computer-readable storage medium storing a computer program. The computer program is operable to cause a computer to execute some or all of the steps of any of the methods described in the foregoing method embodiments. The computer program product may be a software installation package.

[0101] It should be noted that, for the foregoing method embodiments, for simplicity of description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, certain steps may be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0102] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0103] In the several embodiments provided by the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the above division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical or other form.

[0104] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present application.

[0105] In addition, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0106] If the above integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on such an understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions for causing a computer device (which can be a personal computer, a server, or a TRP, etc.) to execute all or part of the steps of the methods in various embodiments of this application. The aforementioned memory includes various media that can store program codes, such as USB flash drives, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), mobile hard disks, magnetic disks, or optical discs.

[0107] Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program. This program can be stored in a computer-readable memory, and the memory can include: flash drives, ROM, RAM, magnetic disks, or optical discs, etc.

[0108] The above has introduced the embodiments of this application in detail. Specific examples are used in this article to elaborate on the principles and implementation manners of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A motor control method, characterized in that: The invention is applied to a ventricular assist device, the ventricular assist device comprises a housing, an impeller arranged in the housing, and a motor driving the impeller to rotate in suspension, the motor comprises a rotor fixed to the impeller and a stator driving the rotor to rotate in suspension, the stator comprises a first stator and a second stator, the rotor comprises a first rotor and a second rotor, the first rotor and the second rotor each comprise a plurality of magnetic blocks, the plurality of magnetic blocks of the first rotor are spliced ​​into a first annular structure, the plurality of magnetic blocks of the second rotor are spliced ​​into a second annular structure, the positions of the plurality of magnetic blocks of the first rotor are respectively arranged in one-to-one correspondence with the positions of the plurality of magnetic blocks of the second rotor, so as to form a plurality of magnetic block groups corresponding to the positions, in each of the magnetic block groups, the magnetizing directions of the magnetic blocks of the first rotor and the magnetic blocks of the second rotor are the same, and the outer peripheral walls of the magnetic blocks of the first rotor are opposite to the inner peripheral walls of the magnetic blocks of the second rotor; the method comprises: Applying a first suspension current to the first stator and applying a first rotation current to the second stator to suspend and control the impeller to rotate at a first position; When the rotation speed of the impeller reaches a target rotation speed, a second rotation current is applied to the first stator, and the first suspension current and the second rotation current are applied to the second stator.

2. The method according to claim 1, characterized in that: The first rotor and the second rotor are both annular, and are concentrically and coaxially arranged; along the central axis direction of the first rotor, the position of the first stator corresponds to the position of the first rotor, and is used to drive the first rotor to suspend and / or rotate; along the central axis direction of the second rotor, the position of the second stator corresponds to the position of the second rotor, and is used to drive the second rotor to suspend and / or rotate.

3. The method according to claim 2, characterized in that The outer peripheral wall of the first rotor is fixedly connected to the inner peripheral wall of the second rotor.

4. The method according to any one of claims 1 to 3, characterized in that: The first stator includes 3N first winding units, and the second stator includes 3N second winding units. The 3N first winding units are arranged at equal intervals along a first circle, and the 3N second winding units are arranged at equal intervals along a second circle. The first circle is concentric with the second circle, and N is greater than or equal to 1.

5. The method according to claim 4, characterized in that When the rotation speed of the impeller reaches the target rotation speed, applying the second rotation current to the first stator, and applying the first suspension current and the second rotation current to the second stator, comprises: When the rotation speed of the impeller reaches a target rotation speed, stopping applying the first suspension current to the first stator, and simultaneously applying the first suspension current and the first rotation current to the second stator; When the rotor rotates to an initial zero position, the second rotating current is applied to the first stator, and the second rotating current and the first suspension current are applied to the second stator.

6. The method according to claim 5, characterized in that The magnitude of the second spinning current is 1 / 2 of the magnitude of the first spinning current.

7. The method according to claim 5, characterized in that Every three adjacent first winding units form a first three-phase winding, and every three adjacent second winding units form a second three-phase winding, and along the radial direction of the first stator and / or the second stator, the positions of the first three-phase winding correspond one-to-one to the positions of the second three-phase winding respectively; The initial zero point position is the position where the projection of the center line of the first phase winding unit in the first three-phase winding, the projection of the center line of the first phase winding unit in the second three-phase winding and the projection of the zero point line of the rotor coincide on the target plane, the zero point line is the center line of any magnetic block group or magnetic block in the rotor, and the target plane is a plane perpendicular to the central axis of the first stator and / or the second stator.

8. The method according to claim 1, characterized in that The method further comprises: When the impeller is detected to be deviated, a second suspension current is applied to the first stator to keep the impeller at the first position.

9. The method according to claim 8, characterized in that The magnitude and direction of the second suspension current are respectively determined by the offset amount and offset direction of the impeller.

10. A control unit for a ventricular assist device, characterized in that: The ventricular assist device includes a housing, an impeller disposed in the housing, and a motor driving the impeller to rotate in suspension, the motor including a rotor fixed to the impeller and a stator driving the rotor to rotate in suspension, the stator including a first stator and a second stator, the rotor including a first rotor and a second rotor, the first rotor and the second rotor each including a plurality of magnetic blocks, the plurality of magnetic blocks of the first rotor being spliced ​​into a first annular structure, the plurality of magnetic blocks of the second rotor being spliced ​​into a second annular structure, the positions of the plurality of magnetic blocks of the first rotor being respectively arranged in one-to-one correspondence with the positions of the plurality of magnetic blocks of the second rotor to form a plurality of magnetic block groups corresponding to positions, in each of the magnetic block groups, the magnetizing directions of the magnetic blocks of the first rotor and the magnetic blocks of the second rotor are the same, and the outer peripheral walls of the magnetic blocks of the first rotor are opposite to the inner peripheral walls of the magnetic blocks of the second rotor; the control unit includes one or more processors, and the one or more processors are used to: Applying a first suspension current to the first stator and applying a first rotation current to the second stator to suspend and control the impeller to rotate at a first position; When the rotation speed of the impeller reaches a target rotation speed, a second rotation current is applied to the first stator, and the first suspension current and the second rotation current are applied to the second stator.

11. A ventricular assist device, characterized in that: The ventricular assist device comprises: case; an impeller disposed in the housing; a motor for driving the impeller to rotate in suspension, the motor comprising a rotor connected to the impeller and a stator for driving the rotor to rotate in suspension, the stator comprising a first stator and a second stator, the rotor comprising a first rotor and a second rotor, the first rotor and the second rotor each comprising a plurality of magnetic blocks, the plurality of magnetic blocks of the first rotor being spliced ​​into a first circular ring structure, the plurality of magnetic blocks of the second rotor being spliced ​​into a second circular ring structure, the positions of the plurality of magnetic blocks of the first rotor being respectively arranged in one-to-one correspondence with the positions of the plurality of magnetic blocks of the second rotor to form a plurality of magnetic block groups corresponding to the positions, in each of the magnetic block groups, the magnetizing directions of the magnetic blocks of the first rotor and the magnetic blocks of the second rotor being the same, and the outer peripheral walls of the magnetic blocks of the first rotor being opposite to the inner peripheral walls of the magnetic blocks of the second rotor; A control unit connected to the motor, the control unit being used to execute the steps in the method according to any one of claims 1 to 9.

12. A medical device, characterized in that: The method comprises a processor, a memory and a communication interface, wherein the memory stores one or more programs, and the one or more programs are executed by the processor, and the one or more programs include instructions for executing the steps in the method according to any one of claims 1 to 9.

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for electronic data exchange, wherein the computer program enables a computer to execute the steps of the method according to any one of claims 1 to 9.

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