Motor control method and device

Abstract

The invention provides a motor control method and device, and the method comprises the steps: applying a first suspension current to a first stator, and applying a first rotation current to a second stator, so as to control the suspension of an impeller to rotate at a first position; when the rotation speed of the impeller reaches the target rotation speed, the 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 two stators are arranged, after the impeller reaches the target rotating speed, the first stator and the second stator are used at the same time to control rotation of the impeller, the power consumption of the second stator can be greatly reduced, and therefore the service life of the motor is prolonged.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to a motor control method and device. Background Art

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

[0003] The embodiments of the present application provide a motor control method and device, which use a first stator and a second stator to simultaneously control the suspended rotation of an impeller, thereby extending the life of the motor.

[0004] In a first aspect, an embodiment of the present application provides a motor control method, which is applied to a ventricular assist device, wherein the ventricular assist device includes a housing, an impeller disposed in the housing, and a motor that drives the impeller to rotate in suspension, wherein the motor includes a rotor fixed to the impeller and a stator that drives the rotor to rotate in suspension, wherein the stator includes a first stator and a second stator; the method includes: 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.

[0005] In a second aspect, an embodiment of the present application provides a control unit of a ventricular assist device, the ventricular assist device comprising a housing, an impeller disposed in the housing, and a motor driving the impeller to rotate in suspension, the motor comprising a rotor fixed to the impeller and a stator driving the rotor to rotate in suspension, the stator comprising a first stator and a second stator, the control unit comprising one or more processors, the one or more processors being configured 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.

[0006] In a third aspect, an embodiment of the present application provides a ventricular assist device, the ventricular assist device comprising: case; an impeller disposed in the housing; A motor driving the impeller to rotate in suspension, the motor comprising a rotor connected to the impeller and a stator driving the rotor to rotate in suspension, the stator comprising a first stator and a second stator; A control unit connected to the motor, the control unit is used to execute part or all of the steps described in the method described in the first aspect above.

[0007] In a fourth aspect, an embodiment of the present application provides a medical device, comprising a processor, a memory, a communication interface, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and the program includes instructions for executing some or all of the steps described in the method described in the first aspect above.

[0008] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program for electronic data exchange, wherein the computer program enables a computer to execute some or all of the steps described in the method described in the first aspect above.

[0009] In a sixth aspect, an embodiment of the present application provides a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute some or all of the steps described in the method described in the first aspect of the embodiment of the present application. The computer program product may be a software installation package.

[0010] 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 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 sets two stators, and by using the first stator and the second stator to control the rotation of the impeller at the same time after the impeller reaches the target speed, the power consumption of the second stator can be greatly reduced, thereby extending the life of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 is a schematic structural diagram of a ventricular assist device provided in an embodiment of the present application; Figure 2 is a partial explosion schematic diagram of a ventricular assist device provided in an embodiment of the present application; Figure 3 is a flow chart of a motor control method provided in an embodiment of the present application; Figure 4 The present application provides a schematic diagram of a stator zero point line coinciding with a rotor zero point line; Figure 5 It is a structural schematic diagram of a medical device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0013] In order to help those skilled in the art better understand the technical solutions of the present application, the following is a clear and complete description of 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, not 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 work are within the scope of protection of the present application.

[0014] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. 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 steps or units that are not listed, or also includes other steps or units inherent to these processes, methods, products, or devices.

[0015] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0016] The pump involved in the present application may be a ventricular assist device in a medical assist device, and the pump may be an implantable ventricular assist device (VAD), which may be attached to the left ventricle, or the right ventricle, or both ventricles of the heart. The VAD may further include a magnetically levitated pump capable of delivering the entire output to the left ventricle according to the pulmonary circulation or the blood circulation.

[0017] The embodiments of the present application are described by taking a centrifugal magnetic levitation pump as an example.

[0018] The ventricular assist device can be attached to the heart via a ventricular connection component (such as a top ring, a ventricular cuff, or a ventricular cuff), which 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 propel it to the aorta, thereby circulating to the rest of the patient's vascular system and providing ventricular assist function to the patient.

[0019] See also Figure 1 , Figure 1 The present invention provides a schematic diagram of the structure of a ventricular assist device 100, which particularly relates 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 for driving the impeller 20 to suspend and rotate.

[0020] The housing assembly has a liquid inlet 14, a liquid outlet 15, and a first chamber 30 and a second chamber 40 arranged at intervals. The liquid inlet 14 and the liquid outlet 15 are both connected to the first chamber 30. In the illustrated embodiment, the central axis of the liquid inlet 14 and the central axis of the liquid outlet 15 are perpendicular; the first chamber 30 and the second chamber 40 are arranged along the central axis of the liquid inlet 14. The first chamber 30 has a first chamber wall 31 and a second chamber wall 32 spaced and opposite to each other along the central axis of the liquid inlet 14. The second chamber 40 is arranged close to the second chamber wall 32.

[0021] The impeller 20 is rotatably disposed in the first chamber 30. The impeller 20 is located between the first chamber wall 31 and the second chamber wall 32. Specifically, when the impeller 20 operates smoothly, 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, the external liquid (such as blood) enters the first chamber 30 from the liquid inlet 14 and flows out from the liquid outlet 15.

[0022] The motor 10 includes a stator 11 and a rotor 13, wherein the stator 11 is disposed in the second chamber 40, the rotor 13 is disposed in the first chamber 30, and the rotor 13 is fixedly connected to the impeller 20, wherein the stator 11 can drive the rotor 13 to suspend and rotate, and the impeller 20 can suspend and rotate with the rotor 13. Specifically, the rotor 13 is disposed in the impeller 20. The suspending rotation of the impeller 20 means that the impeller 20 does not contact the cavity wall of the first chamber 30 when rotating.

[0023] For example, the motor 10 may be a three-phase brushless direct current motor (BLDC), the stator 11 having three windings controlled by different corresponding phases U, V, W of the power input controlled by the three-phase motor, and the motor 10 may also include an inverter circuit, which may be used to convert the DC input into a three-phase output. For example, the ventricular assist device 100 may receive a three-phase input of alternating current.

[0024] exist Figure 2 In the illustrated embodiment, the stator 11 includes a first stator 110 and a second stator 120, and the first stator 110 and the second stator 120 are both roughly annular. The first stator 110 includes 3N first winding units, and the 3N first winding units are arranged at equal intervals along a first circle, and the second stator 120 includes 3N second winding units, and the 3N second winding units are arranged at equal intervals along a second circle, wherein the second circle is concentric with the first circle, 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 includes a stator tooth and a stator coil arranged on the stator tooth.

[0025] The rotor 13 includes a first rotor 130 and a second rotor 140, and the first rotor 130 and the second rotor 140 are both fixedly connected to the impeller 20. Specifically, the first rotor 130 and the second rotor 140 are both arranged in the impeller 20. The first rotor 130 and the second rotor 140 are both annular, and the first rotor 130 and the second rotor 140 are concentrically and coaxially arranged, 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 aligned along the axial direction of the first stator 110), and the first stator 110 can drive the first rotor 130 to rotate and suspend, that is, the first stator 110 and the first rotor 130 together constitute 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 aligned along the axial direction of the second stator 120), and the second stator 120 can drive the second rotor 140 to rotate and suspend, that is, the second stator 120 and the second rotor 140 together constitute a second motor. The first motor and the second motor can be controlled independently. In some embodiments, the first motor is used to drive the suspension and / or rotation of the impeller 20, and the second motor is also used to drive the suspension and / or rotation of the impeller 20, for example, the first motor is used to drive the impeller 20 to suspend, and the second motor is used to drive the impeller 20 to rotate. Alternatively, the first motor is used to drive the impeller 20 to suspend and rotate, and the second motor is used to drive the impeller 20 to rotate. For 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 suspend, and the second motor is used to drive the impeller 20 to rotate, while at certain moments, the first motor is used to drive the impeller to rotate, and the second motor is used to drive the impeller to suspend. Among them, since the first rotor 130 and the second rotor 140 are both 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 consistent, so as to achieve synchronous control of the first motor and the second motor.

[0026] 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. For example, the first rotor 130 and the second rotor 140 can be fixedly connected by gluing. In other embodiments, the outer peripheral wall of the first rotor 130 is opposite to and spaced from the inner peripheral wall of the second rotor 140. The outer peripheral wall of the first rotor 130 is the side wall of the first rotor 130 that is 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 that is facing the central axis of the second rotor 140.

[0027] Specifically, the first rotor 130 and the second rotor 140 each include a plurality of magnetic blocks, and the plurality of magnetic blocks of the first rotor 130 are spliced ​​into a first circular ring structure, and the plurality of magnetic blocks of the second rotor 140 are spliced ​​into a second circular ring structure. Each magnetic block is roughly in the shape of a fan ring. 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 a Halbach array, that is, the first rotor 130 is a Halbach array magnet. The magnetic block setting method of the second rotor 140 is roughly the same as the magnetic block setting method of the first rotor 130, and will not be repeated.

[0028] In some embodiments, the positions of the multiple magnetic blocks of the first rotor 130 are respectively arranged in a one-to-one correspondence with the positions of the multiple 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, so as to form a plurality of position-corresponding magnetic block groups, in which in each position-corresponding magnetic block group, the magnetic blocks of the first rotor 130 and the magnetic blocks of the second rotor 140 have the same magnetizing direction, the magnetic blocks of the first rotor 130 and the magnetic blocks of the second rotor 140 are arranged radially of the first rotor 130 and / or the second rotor 140, and the outer peripheral walls of the magnetic blocks of the first rotor 130 are opposite to the inner peripheral walls of the magnetic blocks of the second rotor 140; and in each position-corresponding magnetic block group, the central angle corresponding to the sector ring where the magnetic blocks of the first rotor 130 are located is equal to the central angle corresponding to the sector ring where the magnetic blocks of the second rotor 140 are located. In some embodiments, in the magnetic block group corresponding to each position, 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 wall of the first rotor 130 is fixedly connected or in contact with the outer peripheral wall of the magnetic block of the second rotor 140. In some embodiments, in the magnetic block group corresponding to each position, the magnetic block of the first rotor 130 and the magnetic block of the second rotor 140 are arranged at intervals along the radial direction of the second rotor 140. The outer peripheral wall of the magnetic block of the first rotor 130 is the side wall of the magnetic block 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.

[0029] Each magnetic block of the first rotor 130 has a center line, and the center line is perpendicular to and intersects with 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 with the central axis of the second rotor 140. In the magnetic block group corresponding to each position, the center line of the magnetic block of the first rotor 130 coincides with the center line of the magnetic block of the second rotor 140.

[0030] In 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 the first stator 110 and the second stator 120 in the axial direction of the first stator 110 and / or the second stator 120, and in this case, the rotor 13 has a large radial width. The first stator 110 can drive the rotor 13 to suspend and rotate, and the second stator 120 can also drive the rotor 13 to suspend and rotate. Among them, the first stator 110 and the second stator 120 are independently controlled. In this case, the rotor 13 includes a plurality of magnetic blocks, which are spliced ​​into an annular structure, and at least some 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 multiple magnetic blocks of the rotor 13 are arranged in 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 with the central axis of the rotor 13.

[0031] The impeller 20 moves axially relative to the housing assembly along the rotation axis 21. During rotation, the impeller 20 is suspended in the housing assembly by a contactless bearing, such as a magnetic bearing, which can generate a magnetic suspension system. For example, in some embodiments, magnets (not shown) are also provided in the housing assembly and the impeller 20, respectively. The magnets in the housing assembly and the magnets in the impeller 20 together constitute a magnetic bearing, and 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 together on the impeller 20, so that the impeller 20 is suspended in the first chamber 30 under the state of magnetic balance, thereby realizing the motion state of the impeller 20 suspended and rotating. The control unit 33 can control the suspension posture 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, the attraction and repulsion between the stator 11 and the rotor 13 are used to generate a torsional force, which causes the impeller 20 to rotate in this direction. 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 rotate in suspension in the first chamber 30 .

[0032] 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. 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 result of the sensor 50 and can control the rotation speed and suspension height of the impeller 20 through the motor 10 according to the detection result. Specifically, the suspension height of the impeller 20 is the distance of the impeller 20 relative to the second cavity wall 32.

[0033] Furthermore, the control unit 33 is used to monitor and control the startup and subsequent operation of the motor 10, including executing a three-phase field-oriented control (FOC) method. The control unit 33 can be a module independent of the stator 11, or it 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 for collecting at least one data of the motor 10. The at least one data may 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 pulsation, the fluid flow rate, and the like.

[0034] The sensor 50 includes 3N first position sensors 51 and 3N second position sensors 52. Each first position sensor 51 is arranged between two adjacent first winding units. The first position sensor 51 is used to measure the suspension height and magnetic pole angle of the first rotor 130 corresponding to the first winding unit. Each second position sensor 52 is arranged between two adjacent second winding units. The second position sensor 52 is used to measure the suspension height and magnetic pole angle of the second rotor 140 corresponding to the second winding unit. Specifically, each position sensor is arranged relative to the path through which the rotor 13 on the impeller 20 passes. When the impeller 20 rotates and the S pole and the N pole of the rotor 13 alternately pass near the position sensor, the signal level of the position sensor output indicating the magnetic flux intensity changes in an up-and-down wave shape (such as a square wave or a sine wave). Therefore, by detecting the time change of the output signal of the position sensor, the position relationship of the first rotor 130 relative to the first stator 110 and the position relationship of the second rotor 140 relative to the second stator 120 can be detected, so that the rotation speed and suspension height of the impeller 20 can be calculated.

[0035] For example, the first position sensor 51 and the second position sensor 52 may be a Hall sensor, an eddy current sensor, a distance sensor, or the like.

[0036] The first stator 110 and the second stator 120 are roughly annular, and 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 correspond to the positions of the second three-phase windings one by one, for example, the U phase of the first three-phase winding unit is aligned with the U phase of the second three-phase winding unit along the radial direction of the first stator 110 and / or the second stator 120, the V phase of the first three-phase winding unit is aligned with the V phase of the second three-phase winding unit along the radial direction of the first stator 110 and / or the second stator 120, and the W phase of the first three-phase winding unit is aligned with the W phase of the second three-phase winding unit along the radial direction of the first stator 110 and / or the second stator 120. For example, 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, and the control unit 33 can control the magnetic pole angle and the suspension height of the entire rotor 13 by controlling the magnitude and phase of the current flowing through the stator coil in the first stator 110 and / or the second stator 120; and the control unit 33 controls the suspension height of the rotor 13 to suspend the impeller 20 at a desired axial position relative to the stator 11.

[0037] Among them, the winding units in the first three-phase winding and the second three-phase winding are three windings controlled by different corresponding phases U, V, and W of the voltage input controlled by the 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.

[0038] In combination with the above description, the present application is described below from the perspective of method examples.

[0039] See also Figure 3 , Figure 3 A flow chart of a motor control method provided in an embodiment of the present application is applied to Figure 1-Figure 2 The ventricular assist device 100 is shown. Figure 3 As shown, the method includes the following steps.

[0040] S310, 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.

[0041] After receiving the start command, the control unit 33 first applies a first suspension current to the first stator 110 to suspend the impeller 20 to the first position. After the impeller 20 is suspended to the first position, the control unit 33 can control the impeller 20 to rotate 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 the impeller 20 rotates, thereby reducing or avoiding friction between the impeller 20 and the housing assembly.

[0042] Specifically, the control unit 33 applies a first suspension current to the first three-phase winding in the first stator 110, so that the winding unit of the N-pole magnetic block in the first three-phase winding facing the first rotor 130 appears as an N pole, or the winding unit of the S-pole magnetic block in the first rotor 130 appears as an S pole, so that the first stator 110 and the first rotor 130 generate an axial magnetic thrust, and the axial magnetic thrust causes the impeller 20 to move in the axial direction, thereby realizing the suspension control of the impeller 20. After the impeller 20 is suspended to the first position, the control unit 33 provides 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 controlled by applying alternating current to the winding units of phases U, V, and W generates a torsional force relative to the second rotor 140, and the torsional force drives the impeller 20 to rotate along the rotation axis 21 of the impeller.

[0043] The first position is within a preset suspension range, and the preset suspension range is near the center of the first chamber 30. For example, the preset suspension range is 0.05 mm-0.5 mm.

[0044] Further, if before the suspending impeller 20, the projection of the zero point line O of the rotor 13 and the projection of the zero point line P of the stator 11 do not overlap on the target plane, or there is no winding unit in the first stator 110 facing the magnetic block in the first rotor 130, then the stator coil in the stator 11 has no current and cannot generate an effective axial magnetic force with the rotor 13. The control unit 33 can apply a rotating current to the first stator 110 and / or the second stator 120 to generate a magnetic attraction. 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 exhibit S-pole magnetism, and generate a magnetic attraction with the N-pole magnetism of the rotor 13. The magnetic attraction moves the rotor 13 along its circumferential direction, so that the projection of the zero point line P of the stator 11 and the projection of the zero point line O of the rotor 13 overlap on the target plane.

[0045] like Figure 4As shown, the rotor 13 includes a first rotor 130 and a second rotor 140, each of which includes 8 magnetic blocks. The rotor 13 rotates counterclockwise at a speed w, and the zero point line O of the rotor 13 is the center line of the magnetic block group corresponding to any position of the magnetic pole N on the side of the first rotor 130 and the second rotor 140 close to the stator 11; the first stator 110 and the second stator 120 each 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, and 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, and the zero point line P of the stator 11 is the center line of the U-phase winding unit in the first three-phase winding and the second three-phase winding, that is, the first phase winding unit is a U-phase winding unit. The projection of the center line of the magnetic block group or magnetic block whose magnetic pole is the N pole on the side close to the stator 11 in the rotor 13 coincides with the projection of the center line of the U-phase winding unit of the first three-phase winding and the U-phase winding unit of the second three-phase winding unit 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, for example, a plane parallel to the second cavity wall 32, and a plane parallel to the side of the impeller 20 close to the stator 11. After coinciding the projection of the zero point line P of the stator 11 with the projection of the zero point 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, and controls the impeller 20 to suspend and rotate at the first position.

[0046] The sensor 50 can Figure 4 The positional relationship between the rotor 13 and the stator 11 is marked as the initial zero position of the rotor 13. The subsequent control unit 33 can calculate the current magnetic pole angle of the rotor 13 according to the position change of the rotor 13 relative to the initial zero position.

[0047] It should be noted that the zero point line O of the rotor 13 may also be the center line of a magnetic block group or a magnetic block whose magnetic pole is the S pole on the side close to the stator 11 in the first rotor 130 and the second rotor 140. The zero point line P of the stator 11 may also be the center line of the V-phase winding unit in the first three-phase winding and the second three-phase winding, or the center line of the W-phase winding unit, that is, the first phase winding unit may be a V-phase winding unit or a 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 with the central axis of the stator 11.

[0048] S320. 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.

[0049] The target speed is within the speed range allowed during normal operation of the ventricular assist device 100, which is 2200RPM to 4300RPM. When the first rotating current is applied to the second stator 120 to rotate the impeller 20 at the target speed, the second stator 120 requires more power consumption, thereby generating more heat, which is transferred to the impeller 20 and the housing assembly, causing the temperature inside the ventricular assist device 100 to rise. Excessive temperature increases the risk of thrombosis and hemolysis, and also affects the use of the stator 11, thereby affecting user safety and the service life of the motor 10.

[0050] Therefore, when the rotation speed of the impeller 20 reaches the target speed, the control unit 33 also applies a rotation current to the first stator 110, so that the rotation current applied to the second stator 120 can be reduced, thereby reducing the power consumption generated by the second stator 120 and extending the service life of the second stator 120.

[0051] Optionally, when the rotation speed of the impeller reaches the target speed, the 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, including: when the rotation speed of the impeller reaches the target speed, stop applying the first suspension current to the first stator, and simultaneously apply the first suspension current and the first rotation current to the second stator; when the rotor rotates to an initial zero position, apply the second rotation current to the first stator, and apply the second rotation current and the first suspension current to the second stator.

[0052] In the present application, when the rotation speed of the impeller 20 reaches the target speed, the control unit 33 can control the application of a rotating 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, thereby reducing the power consumption generated by the second stator 120.

[0053] Since directly applying the second rotating current to the first stator 110 may cause the motor 10 to run unstably, the control unit 33 first stops applying the first suspension current to the first stator 110, and applies the first suspension current to the second stator 120 at the same time, 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 rotor zero point line O line coincide with the projection line P line of the stator on the target plane, that is, when the first rotor 130 is at the initial zero point position, the control unit 33 applies the second rotating current to the first stator 110, and reduces the rotating current applied to the second stator 120 at the same time, which can avoid the deviation of the rotation control of the rotor 13 caused by the asynchronism between driving the first rotor 130 and the second rotor 140. Specifically, the first suspension current is continuously applied to the second stator 120, and the second rotating current is also applied to the second stator 120, so that the impeller 20 is stabilized at the first position and rotates at the target speed.

[0054] Among them, the magnitude of the second rotating current is 1 / 2 of the magnitude of the first rotating current. The impeller 20 keeps rotating at the first position at the target speed, and the torsional force driving the impeller 20 to rotate remains unchanged. Therefore, when the rotation current applied to the second stator 120 to drive the impeller 20 to rotate changes to the rotation current applied to the first stator 110 and the second stator 120 to drive the impeller 20 to rotate, the rotating current applied by the control unit 33 will not change, that is, the sum of the rotating current applied by the control unit 33 to the first stator 110 and the rotating current applied to the second stator 120 is equal to the first rotating current. In order to reduce the heat generated by the motor 10 as much as possible, the control unit 33 applies the same rotating current to the first stator 110 and the second stator 120. That is to say, the control unit 33 simultaneously applies a second rotating current to the first stator 110 and the second stator 120, and the second rotating current is 1 / 2 of the first rotating current, so that the sum of the torque force generated by the first stator 110 on the first rotor 130 and the torque force generated by the second stator 120 on the second rotor 140 can make the impeller 20 rotate at the target speed.

[0055] In another possible example, when the rotation 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 rotation current to the first stator 110, and reduces the rotation current applied to the second stator 120, and applies the second rotation current to the second stator 120, and provides an axial suspension force and half of the torque force through the first stator 110, and the second stator 120 provides the other half of the torque force, so as 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 extending the life of the motor 10.

[0056] Optionally, the method further includes: when a deviation of the impeller is detected, applying a second suspension current to the first stator to keep the impeller in the first position.

[0057] 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, causing the impeller to deviate or tilt. The inclination of the impeller 20 will make the operation of the impeller 20 unstable, and may even contact the housing assembly to cause surface damage between the impeller 20 and the inner wall of the housing assembly, causing fluid retention or thrombosis; and the deviation 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. Therefore, the control unit 33 monitors whether the impeller 20 is deviated or tilted in real time according to the signals fed back by the first position sensor 51 and the second position sensor 52. When the impeller 20 is deviated or tilted, the second suspension current is additionally applied to the first stator 110 to generate an axial force opposite to the deviation or tilt, adjust the suspension posture of the impeller 20, stably suspend the impeller 20 at the first position, and improve the stability of the operation of the impeller 20.

[0058] For example, if the control unit 33 applies a first suspension current to the first stator 110 to drive the impeller 20 to suspend, then after 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 posture of the impeller 20 is adjusted by the second suspension current, so that the impeller 20 is stably suspended at the first position.

[0059] The magnitude and direction of the second suspension current are respectively determined by the offset amount and offset direction of the impeller 20 .

[0060] Specifically, if the impeller 20 is offset or tilted toward the first cavity wall 31, an additional axial force toward the second cavity wall 32 needs to be provided to the rotor 13; if the impeller 20 is offset or tilted toward the second cavity wall 32, an additional axial force toward the first cavity wall 31 needs to be provided to the rotor 13. The axial force toward the first cavity wall 31 may be a magnetic thrust generated between the first winding unit of the first stator 110 and the magnetic block in the first rotor 130 facing it; the axial force toward the second cavity wall 32 may be a magnetic attraction generated between the first winding unit of the first stator 110 and the magnetic block in the first rotor 130 facing it.

[0061] 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 a first suspension current to the second three-phase winding in the second stator 120, so that the winding unit of the second three-phase winding that is opposite to the N-pole magnetic block in the second rotor 140 appears as an N-pole, or the winding unit of the S-pole magnetic block that is opposite to the second rotor 140 appears as an S-pole, so that the second stator 120 and the second rotor 140 generate axial magnetic thrust, and the axial magnetic thrust causes the impeller 20 to move axially, thereby realizing suspension control of the impeller 20.

[0062] Since the magnetic blocks in the first rotor 130 and the second rotor 140 are placed in the same manner, and the winding units in the first stator 110 and the second stator 120 are placed in the same manner, the magnetic blocks in the first rotor 130 directly facing the winding units in the first stator 110 and the magnetic blocks in the second rotor 140 directly facing the winding units in the second stator 120 are in the same magnetic block group or are the same magnetic blocks. When it is necessary to provide magnetic thrust, the magnetic poles of the first winding units in the first stator 110 directly facing the magnetic blocks in the first rotor 130 are the same as the magnetic poles of the second winding units in the second stator 120 directly facing the magnetic blocks in the second rotor 140; when it is necessary to provide magnetic attraction, the magnetic poles of the first winding units in the first stator 110 directly facing the magnetic blocks in the first rotor 130 are opposite to the magnetic poles of the second winding units in the second stator 120 directly facing the magnetic blocks in the second rotor 140. That is, when an axial force toward 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 toward 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.

[0063] Furthermore, the larger the offset distance or the deflection angle of the impeller 20, the larger the required magnetic thrust or magnetic attraction, and thus the larger the magnitude of the second suspension current. The offset distance is the axial distance of the impeller 20 relative to the first position, and the inclination angle is the angle between the plane of the impeller 20 facing the first cavity wall 31 and the target plane.

[0064] 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 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 sets two stators, and by using the first stator and the second stator to control the rotation of the impeller at the same time after the impeller reaches the target speed, the power consumption of the second stator can be greatly reduced, thereby extending the life of the motor.

[0065] The above mainly introduces the scheme of the embodiment of the present application from the perspective of the execution process on the method side. It is understandable that in order to realize the above functions, the network device includes a hardware structure and / or software module corresponding to each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiment provided in this article, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0066] For example, the present application also provides a control unit of a ventricular assist device, the ventricular assist device comprising a housing, an impeller disposed in the housing, a motor driving the impeller to rotate in suspension, the motor comprising a rotor embedded in the impeller and a stator driving the rotor to rotate in suspension, the stator comprising a first stator and a second stator, the control unit comprising one or more processors, the one or more processors being 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.

[0067] For example, the present application also provides a ventricular assist device, the ventricular assist device comprising: case; an impeller disposed in the housing; A motor driving the impeller to rotate in suspension, the motor comprising a rotor embedded in the impeller and a stator driving the rotor to rotate in suspension, the stator comprising a first stator and a second stator; The control unit connected to the motor is used to execute part or all of the steps described in the above method.

[0068] As an example, the present application also provides a medical device, which includes the control unit or ventricular assist device described above.

[0069] Among them, the control unit of each of the above schemes has the function of implementing the corresponding steps performed by the medical device in the above method; the functions can be implemented by hardware, or by hardware executing corresponding software.

[0070] In the embodiment of the present application, the control unit may also be a chip or a chip system, for example, a system on chip (SoC).

[0071] See also Figure 5 , Figure 5 It is a structural diagram of a medical device provided in an embodiment of the present application, wherein the medical device comprises: 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 memories and are configured to be executed by the one or more processors.

[0072] The above program includes instructions for performing the following steps: 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.

[0073] Among them, all relevant contents of each scenario involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0074] It should be understood that the above-mentioned memory may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type.

[0075] In the embodiment of the present application, the processor of the above-mentioned device may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) 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.

[0076] It should be understood that the "at least one" involved in the embodiments of the present application refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0077] Furthermore, unless otherwise specified, 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, and do not indicate the difference in content, priority, sending order or importance of the two types of information.

[0078] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software units in a processor for execution. The software unit can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor executes the instructions in the memory, and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0079] An embodiment of the present application also provides a computer storage medium, wherein the computer storage medium stores a computer program for electronic data exchange, and the computer program enables a computer to execute part or all of the steps of any method recorded in the above method embodiments.

[0080] The present application also provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute some or all of the steps of any method described in the above method embodiment. The computer program product may be a software installation package.

[0081] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0082] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0083] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the above-mentioned units, which is only a logical function division. There may be other division methods in actual implementation, such as 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 mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0084] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0085] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0086] If the above-mentioned 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 this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a memory, including a number of instructions to enable a computer device (which can be a personal computer, server or TRP, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned memory includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, RandomAccess Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0087] A person skilled in the art may understand that all or part of the steps in the various methods of the above embodiments may be completed by instructing the relevant hardware through a program, and the program may be stored in a computer-readable memory, which may include a flash drive, ROM, RAM, a magnetic disk or an optical disk, etc.

[0088] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A motor control method, characterized in that: Applied to a ventricular assist device, the ventricular assist device comprises a housing, an impeller disposed in the housing, and a motor driving the impeller to rotate in suspension, the motor comprising a rotor fixed to the impeller and a stator driving the rotor to rotate in suspension, the stator comprising a first stator and a second stator; 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 rotor includes a first rotor and a second rotor, the first rotor and the second rotor are both annular, and the first rotor and the second rotor 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, which 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, which is used to drive the second rotor to suspend and / or rotate.

3. The method according to claim 2, characterized in that The first rotor and the second rotor each include a plurality of magnetic blocks, wherein the plurality of magnetic blocks of the first rotor are spliced ​​into a first circular ring structure, and the plurality of magnetic blocks of the second rotor are spliced ​​into a second circular ring structure, and 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 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.

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

5. The method according to claim 1, characterized in that The rotor comprises a plurality of magnetic blocks which are spliced ​​into an annular structure. At least part of the magnetic blocks are magnetized along the axial direction of the rotor. Also, along the circumferential direction of the rotor, the magnetic poles of adjacent axially magnetized magnetic blocks are opposite.

6. The method according to any one of claims 2 to 5, 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.

7. The method according to claim 6, 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.

8. The method according to claim 7, characterized in that The magnitude of the second spinning current is 1 / 2 of the magnitude of the first spinning current.

9. The method according to claim 7, 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.

10. 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.

11. The method according to claim 10, 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.

12. A control unit for a ventricular assist device, characterized in that: The ventricular assist device comprises a housing, an impeller disposed in the housing, and a motor driving the impeller to rotate in suspension, the motor comprising a rotor fixed to the impeller and a stator driving the rotor to rotate in suspension, the stator comprising a first stator and a second stator, and the control unit comprising one or more processors, wherein 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.

13. A ventricular assist device, characterized in that: The ventricular assist device comprises: case; an impeller disposed in the housing; A motor driving the impeller to rotate in suspension, the motor comprising a rotor connected to the impeller and a stator driving the rotor to rotate in suspension, the stator comprising a first stator and a second stator; 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 1-11.

14. 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 11.

15. 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 11.

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