Method and device for starting ventricular assist device

Abstract

The invention provides a ventricular assist device starting method and device, and the method comprises the steps: applying a first current to a first stator and a second stator at a first moment, and enabling the zero lines of the stators and a rotor to coincide; at a second moment, stopping applying the first current to the second stator, and applying a second current to the first stator to suspend the rotor; after the rotor is suspended to the first position, a third current is applied to the second stator, and the rotor is controlled to rotate at the target rotating speed at the first position. The two stators are arranged, the first stator controls the rotor to suspend to the first position, and the second stator controls the rotor to rotate at the first position, so that the rotor rotates after being suspended, frictional resistance generated when the impeller and the shell slide relatively is avoided, thrombus generated by surface damage of the impeller and the inner wall of the shell is reduced, and the service life of the impeller is prolonged. And user safety is improved.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to a method and device for activating a ventricular assist device. Background Art

[0002] A 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 a pump housing to push the fluid through the pump housing from the inlet end to the outlet end of the pump, thereby achieving the fluid pumping function.

[0003] When the ventricular assist device is required to operate or the operation of the impeller is suspended, it is desirable to effectively start or resume the operation of the pump to achieve fluid pumping. However, starting the impeller can be difficult, especially when the impeller is magnetically attracted to the housing of the pump. Summary of the invention

[0004] The embodiments of the present application provide a method and device for starting a ventricular assist device, which can reduce the friction between the impeller and the casing when the impeller starts to rotate, thereby avoiding damage to the inner wall surface of the casing assembly and the impeller due to friction, thereby preventing fluid embolism or condensation.

[0005] In a first aspect, an embodiment of the present application provides a method for starting a ventricular assist device, wherein the ventricular assist device comprises a housing, an impeller disposed in the housing, and a motor driving the impeller to rotate in suspension, wherein the motor comprises a rotor fixed to the impeller and a stator driving the rotor to rotate in suspension, wherein the stator comprises a first stator and a second stator; the method comprises:

[0006] At a first moment, applying a first current to the first stator and the second stator to make the zero point lines of the stator and the rotor coincide with each other;

[0007] At a second moment, stopping applying the first current to the second stator and applying a second current to the first stator to suspend the rotor;

[0008] After the rotor is suspended to the first position, a third current is applied to the second stator to control the rotor to rotate at the first position.

[0009] 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:

[0010] At a first moment, applying a first current to the first stator and the second stator to make the zero point lines of the stator and the rotor coincide with each other;

[0011] At a second moment, stopping applying the first current to the second stator and applying a second current to the first stator to suspend the rotor;

[0012] After the rotor is suspended to the first position, a third current is applied to the second stator to control the rotor to rotate at the first position.

[0013] In a third aspect, an embodiment of the present application provides a ventricular assist device, characterized in that the ventricular assist device comprises:

[0014] case;

[0015] an impeller disposed in the housing;

[0016] A motor driving the impeller to rotate in suspension, the motor comprising a rotor fixedly connected to the impeller and a stator driving the rotor to rotate in suspension, the stator comprising a first stator and a second stator;

[0017] The control unit connected to the motor is used to execute part or all of the steps described in the method described in the first aspect above.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] The technical solution provided by the present application is that at the first moment, a first current is applied to the first stator and the second stator to coincide the zero point line of the stator and the rotor; at the second moment, the first current is stopped from being applied to the second stator, and the second current is applied to the first stator to suspend the rotor; after the rotor is suspended to the first position, a third current is applied to the second stator to control the rotor to rotate at the target speed at the first position. The present application sets two stators, the first stator controls the rotor to suspend to the first position, and the second stator controls the rotor to rotate at the first position, so that the rotor is suspended and then rotates, avoiding the friction resistance when the impeller and the housing slide relative to each other, thereby reducing the thrombus caused by the surface damage of the inner wall of the impeller and the housing, and improving user safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 is a schematic structural diagram of a ventricular assist device provided in an embodiment of the present application;

[0024] Figure 2 is a partial explosion schematic diagram of a ventricular assist device provided in an embodiment of the present application;

[0025] Figure 3 It is a flowchart of a method for starting a ventricular assist device provided in an embodiment of the present application;

[0026] Figure 4 is a schematic diagram of a rotor zero point line provided in an embodiment of the present application;

[0027] Figure 5 is a schematic diagram of a stator zero point line provided in an embodiment of the present application;

[0028] Figure 6 The present application provides a schematic diagram of a stator zero point line coinciding with a rotor zero point line;

[0029] Figure 7 is a schematic diagram of the positions of a rotor and a stator at time T1 provided by an embodiment of the present application;

[0030] Figure 8 is a schematic diagram of the positions of a rotor and a stator at time T2 provided by an embodiment of the present application;

[0031] Fig. 9 The embodiment of the present application provides a top view of the position of the rotor and the stator at time T2;

[0032] Fig.10 is a schematic diagram of the positions of a rotor and a stator at time T3 provided by an embodiment of the present application;

[0033] Fig.11 The embodiment of the present application provides a top view of the rotor and the stator at the time T3;

[0034] Fig.12 is a schematic diagram of the positions of a rotor and a stator at time T4 provided by an embodiment of the present application;

[0035] Fig.13 The embodiment of the present application provides a top view of the rotor and the stator at the time T4;

[0036] Fig.14 is a schematic diagram of the positions of a rotor and a stator at time T5 provided by an embodiment of the present application;

[0037] Fig.15 The embodiment of the present application provides a top view of the rotor and the stator at the time T5;

[0038] Fig.16 is a schematic diagram of the positions of a rotor and a stator at time T6 provided by an embodiment of the present application;

[0039] Fig.17 The embodiment of the present application provides a top view of the rotor and the stator at the time T6;

[0040] Fig.18 is a schematic diagram of the positions of a rotor and a stator at time T7 provided by an embodiment of the present application;

[0041] Fig.19 The embodiment of the present application provides a top view of the rotor and the stator at the time T7;

[0042] Fig. 20 It is a structural schematic diagram of a medical device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] The embodiments of the present application are described by taking a centrifugal magnetic levitation pump as an example.

[0048] The ventricular assist device can be attached to the heart via a ventricular connection assembly (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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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. 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. 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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 and the first stator 110 and the second stator 120 are aligned in the axial direction of the first stator 110 and / or the second stator 120, and in this case, the rotor 130 has a large radial width. The first stator 110 can drive the rotor 13 to suspend and rotate, and the second stator 140 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 130.

[0061] 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, the housing assembly and the impeller 20 are also provided with magnets (not shown), and 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 of 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 chamber 10 .

[0062] 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.

[0063] Further, 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 at both ends of the pump, the flow pulsation, the fluid flow rate, etc.

[0064] 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.

[0065] 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.

[0066] The first stator 110 and the second stator 120 are substantially annular, and every three adjacent first winding units 110 among the 3N first winding units 110 form a first three-phase winding, and every three adjacent first winding units 120 among the 3N second winding units 120 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 current magnitude and phase of the stator coil flowing through the first winding unit 110 and / or the second winding unit 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.

[0067] 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.

[0068] In combination with the above description, the present application is described below from the perspective of method examples.

[0069] See also Figure 3 , Figure 3 A schematic flow chart of a method for starting a ventricular assist device 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.

[0070] S310. At a first moment, apply a first current to the first stator and the second stator to make the zero point lines of the stator and the rotor coincide with each other.

[0071] When the ventricular assist device 100 is not in operation, the impeller 20 will be parked on the side of the second chamber wall 32 due to the attraction of the stator 11 to the rotor 13. At this time, the suspension height of the impeller 20 relative to the second chamber wall 32 is 0, that is, the impeller 20 is in contact with the second chamber wall 32. In this case, when the ventricular assist device 100 responds to the user's operation to start the rotation of the impeller 20, the contact between the impeller 20 and the chamber wall in the first chamber 30 causes the impeller 20 to rotate, which will increase the relative sliding friction resistance between the impeller 20 and the housing assembly, causing surface damage to the impeller 20 and the inner wall of the housing assembly, which is likely to cause fluid retention or thrombosis.

[0072] To this end, when receiving a start command for starting the impeller 20 to rotate, the control unit 33 of the present application can first control the rotor 13 to suspend so that the impeller 20 is separated from the second cavity wall 32 or is in a non-contact state, thereby avoiding thrombosis caused by surface damage of the impeller 20 and the second cavity wall 32 caused by friction between the impeller 20 and the second cavity wall 32.

[0073] When the ventricular assist device 100 is stationary (not running), since no current is applied to the stator coil in the stator 11, the coincidence of the zero point line of the stator 11 and the zero point line of the rotor 13 is unknown, that is, the rotor 13 is not directly opposite to the winding units in the stator 11, so that the stator coil in the stator 11 has no current and cannot generate effective axial magnetic force with the rotor 13.

[0074] In the present application, before the rotor 13 is suspended, the control unit 33 first controls the rotor 13 to move along the circumferential direction of the rotor 13 to coincide with the zero-point line of the stator 11 and the zero-point line of the rotor 13, so that the rotor 13 can be suspended and rotated later. When the rotor 13 includes a plurality of magnetic blocks, the zero-point line of the rotor 13 is the center line of any magnetic block. When the rotor 13 includes a first rotor 130 and a second rotor 140, the zero-point line of the rotor 13 is the center line of the magnetic block of the first rotor 130 and / or the center line of the magnetic block of the second rotor 140 in any position corresponding magnetic block group (since the center line of the magnetic block of the first rotor 130 and the center line of the magnetic block of the second rotor 140 coincide in the position corresponding magnetic block group, therefore, at this time, the zero-point line of the rotor 13 is also the center line of the magnetic block of the first rotor 130 and / or the center line of the magnetic block of the second rotor 140 in the position corresponding magnetic block group).

[0075] Optionally, applying a first current to the first stator and the second stator to make the zero point line of the stator coincide with that of the rotor includes: applying the first current to the first phase winding unit in the first three-phase winding and the second three-phase winding, respectively, so that 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 a 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.

[0076] For example, Figure 4 As 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. Figure 5 As shown, 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. The zero point line P line 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 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.

[0077] It should be noted that the zero point line O of the rotor 13 may also be the center line of the magnetic block group of the S pole of any magnetic 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.

[0078] After receiving the start command, the control unit 33 applies 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 at the first moment, 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 magnetic attraction with the magnetic block of the N-pole magnetism of the rotor 13, and the magnetic attraction moves the rotor 13 along its circumferential direction, so that the projection of the zero point line P line of the stator 11 and the projection of the zero point line O line of the rotor 13 coincide with each other on the target plane, that is, the projection of the center line of the magnetic block group or magnetic block whose magnetic pole is 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 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.

[0079] For example, 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 on the target plane overlap as shown in FIG. Figure 6 As shown, the sensor 50 may mark the position as a zero point, which is the initial zero point position of the rotor 13. The control unit 33 may subsequently calculate the current rotation speed of the rotor 13 according to the position change of the rotor 13 relative to the stator 11.

[0080] S320. At a second moment, stop applying the first current to the second stator, and apply a second current to the first stator to suspend the rotor.

[0081] After 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 are overlapped on the target plane and the initial zero point position of the rotor 13 is clarified, the control unit 33 can then suspend and rotate the rotor 13. The first stator 110 can control the suspension and rotation of the first rotor 130, and the second stator 120 can control the suspension and rotation of the second rotor 140. During the startup process of the motor 10, the first stator 110 can be used to control the suspension of the rotor 13, and the second stator 120 can control the rotation of the rotor 13; the first stator 110 can also be used to control the rotation of the rotor 13, and the second stator 120 can control the suspension of the rotor 13. The embodiment of the present application is described by the first stator 110 controlling the suspension of the rotor 13 and the second stator 120 controlling the rotation of the rotor 13.

[0082] At the second moment, the control unit 33 controls the rotor 13 to suspend, so that the impeller 20 is separated from or in a non-contact state with the second cavity wall 32. Specifically, after 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 are overlapped on the target plane, the control unit 33 stops providing current to the second stator 120, that is, stops applying the first current to the U-phase winding unit of the second three-phase winding, and simultaneously applies the second current to the first stator 110, so that the rotor 13 can suspend.

[0083] Since the rotor 13 is at the initial zero position at this time, the U-phase winding unit of the first three-phase winding is directly opposite to the magnetic block with the N-pole in the first rotor 130. In order to make the rotor 13 levitate, the control unit 33 can change the direction of the current flowing through the first stator 110 (i.e., change the direction of the current applied to the U-phase winding unit of the first three-phase winding), so that the magnetic pole of the U-phase winding unit of the first three-phase winding changes from the S-pole to the N-pole. The U-phase winding unit of the first three-phase winding with the N-pole magnetic pole and the magnetic block with the N-pole in the first rotor 130 generate an axial magnetic thrust, which causes the impeller 20 to move in the axial direction, thereby realizing the suspension control of the impeller 20.

[0084] The direction of the second current is opposite to that of the first current, and the second current can gradually increase, so that the suspension height of the impeller 20 relative to the second cavity wall 32 increases. In other words, the second current is a straight line in an ascending state opposite to the direction of the first current.

[0085] S330: After the rotor is suspended to the first position, a third current is applied to the second stator to control the rotor to rotate at the first position.

[0086] In the present application, if the impeller 20 contacts the housing assembly during rotation, the relative sliding friction resistance between the impeller 20 and the housing assembly will increase due to the rotation of the impeller 20, thereby causing surface damage to the impeller 20 and the inner wall of the housing assembly, causing fluid retention or thrombosis. To avoid this problem, during the rotation of the impeller 20, the control unit 33 should try to control the impeller 20 to suspend and rotate near the center of the first chamber 30, or control the axial movement range of the rotor 13 and the impeller 20 in the axial direction (parallel to the rotation axis 21).

[0087] During the suspension process of the impeller 20, the first position sensor 51 can monitor the suspension height of the impeller 20 in real time. After the impeller 20 is suspended to the first position, the control unit 33 can control the rotor 13 to rotate. The suspension height in the present application refers to the distance value of the first rotor 13 relative to the first position sensor 51 in the axial direction. Since the positions of the first position sensor 51 and the first stator 110 are fixed, the suspension height can also refer to the distance value of the first rotor 130 relative to the first stator 110 or the first winding unit and the second winding unit in the axial direction, and the distance value can be characterized by the magnetic flux intensity detected by the first position sensor 51.

[0088] 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.

[0089] After the impeller 20 is suspended 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 third 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.

[0090] Specifically, the control unit 33 provides a three-phase AC current to the second three-phase winding in the second stator 120, and each phase of the AC current differs by 120 degrees. The second three-phase winding controlled by applying AC 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.

[0091] Optionally, after applying the third current to the second stator, the method further includes: acquiring a target magnetic pole angle, where the target magnetic pole angle is the magnetic pole angle detected by the second position sensor; and controlling application of a fourth current to the first stator according to the target magnetic pole angle.

[0092] During the rotation of the impeller 20, the impeller 20 needs to be stabilized in the first position to improve the stability and efficiency of the operation of the motor 10. Therefore, the magnitude and direction of the force provided by the first stator 110 to the first rotor 130 in the axial direction cannot be changed, and during the rotation of the second rotor 140, the first rotor 130 will make the impeller 20 rotate synchronously, so that the magnetism of the magnetic block of the first rotor 130 facing the first winding unit in the first three-phase winding changes alternately. The change of the magnetic pole in the first rotor 130 will change the direction and / or magnitude of the force generated by the first stator 110 on the first rotor 130, making the impeller 20 unstable in suspension.

[0093] Based on this, after applying the third current to the second stator 120, the control unit 33 determines the fourth current to be applied to the first stator 110 according to the magnetic pole angle of the first rotor 130 relative to the first stator 110. During the rotation of the second rotor 140, the second position sensor 52 detects the magnetic pole angle of the second rotor 140 relative to the second stator 120 in real time. The magnetic pole angle is the angle between the magnetic block on the second rotor 140 and the second winding unit in the second stator 120, that is, the angle between the zero point line P of the stator 11 and the zero point line O of the rotor 13. At the initial zero point position, the magnetic pole angle is 0.

[0094] In the present application, the magnetic force generated between the first rotor 130 and the first stator 110 causes the impeller 20 to float at the first position. In order to keep the impeller 20 suspended at the first position, the magnitude and direction of the magnetic force generated in the axial direction between the first rotor 130 and the first stator 110 remain unchanged. Therefore, the control unit 33 can keep the magnitude of the current applied to the first stator 110 unchanged to keep the magnitude of the magnetic force generated by it unchanged, and then determine the direction of the current according to the change of the magnetic pole of the magnetic block in the first rotor 130.

[0095] Since the magnetic blocks in the first rotor 130 and the second rotor 140 are placed in the same manner, the control unit 33 obtains the target magnetic pole angle detected by the second position sensor 52, and determines the first winding unit directly facing the magnetic block in the current first rotor 130 according to the target magnetic pole angle. Then, by applying the fourth current to the first winding unit directly facing the magnetic block, the magnitude of the magnetic force generated between the first winding unit and the first rotor 130 in the axial direction remains unchanged, and the direction of applying the fourth current is determined by determining the magnetic pole in the first rotor 130 directly facing the magnetic block.

[0096] Optionally, the control of applying a fourth current to the first stator according to the target magnetic pole angle includes: when the target magnetic pole angle is a first angle, applying the fourth current to a first phase winding unit in the first three-phase winding unit, the first angle being that the first phase winding unit in the first three-phase winding is directly opposite to a target magnetic block in the rotor, and the target magnetic block is a magnetic block with an N pole or an S pole; when the target magnetic pole angle is a second angle, applying the fourth current to a second phase winding unit in the first three-phase winding unit, the second angle being that the second phase winding unit in the first three-phase winding is directly opposite to the target magnetic block in the rotor; when the target magnetic pole angle is a third angle, applying the fourth current to a third phase winding unit in the first three-phase winding unit, the third angle being that the third phase winding unit in the first three-phase winding is directly opposite to the target magnetic block in the rotor.

[0097] When the magnetic pole of the target magnetic block is the N pole, the current direction of the fourth current is the same as the current direction of the second current; when the magnetic pole of the target magnetic block is the S pole, the current direction of the fourth current is opposite to the current direction of the second current.

[0098] Since the magnetic blocks in the first rotor 130 and the second rotor 140 are arranged in the same manner, the positions of the first three-phase winding and the second three-phase winding are also the same. For example, when the magnetic pole of the magnetic block where the zero line O of the rotor 13 is located is the N pole, if the magnetic pole of the magnetic block directly facing the first winding unit in the current first rotor 130 is still the N pole, the control unit 33 can apply a fourth current with the same current direction and current magnitude as the second current to the first stator 110; if the magnetic pole of the magnetic block directly facing the first winding unit in the current first rotor 130 becomes the S pole, the control unit 33 can apply a fourth current with the opposite current direction and the same current magnitude as the second current to the first stator 110, so that the magnitude and direction of the magnetic force generated in the axial direction between the first stator 110 and the first rotor 130 remain unchanged, and the impeller 20 can be stably suspended in the first position during the suspension process of the impeller 20.

[0099] For example, when the magnetic pole of the magnetic block where the zero point line O of the rotor 13 is located is the S pole, if the magnetic pole of the magnetic block directly opposite to the first winding unit in the current first rotor 130 becomes the N pole, the control unit 33 can apply a fourth current with the same current magnitude and opposite to the current direction of the second current to the first stator 110; if the magnetic pole of the magnetic block directly opposite to the first winding unit in the current first rotor 130 is still the S pole, the control unit 33 can apply a fourth current with the same current direction and magnitude as the second current to the first stator 110, so that the magnitude and direction of the magnetic force generated in the axial direction between the first stator 110 and the first rotor 130 remain unchanged, and the impeller 20 can be stably suspended in the first position during the suspension process of the impeller 20.

[0100] The target magnetic block is a magnetic block directly opposite to the first winding unit. If the first winding unit directly opposite to the target magnetic block is a first phase winding unit, the fourth current can be applied to the first phase winding unit in the first stator 110; if the first winding unit directly opposite to the target magnetic block is a second phase winding unit, the fourth current can be applied to the second phase winding unit in the first stator 110; if the first winding unit directly opposite to the target magnetic block is a third phase winding unit, the fourth current can be applied to the third phase winding unit in the first stator 110. Among them, the first three-phase winding in the first stator 110 includes a U-phase winding unit, a V-phase winding unit, and a W-phase winding unit respectively. The first phase winding unit can be a U-phase winding unit, the second phase winding unit can be a V-phase winding unit, and the third phase winding unit can be a W-phase winding unit.

[0101] For example, the first stator 110 and the second stator 120 include 6 winding units, and the first rotor 130 and the second rotor 140 include 8 magnetic blocks. The starting process of the motor 10 is described in detail. The positions of the stator 11 and the rotor 13 are as follows: Figure 7-Figure 19 .

[0102] Among them, the first stator 110 controls the suspension of the impeller 20, and the second stator 120 controls the rotation of the impeller 20. The distribution angles of the stator core and the stator coil of the first stator 110 and the second stator 120 are consistent, the magnetic pole distribution of the first rotor 130 and the second rotor 140 is consistent, the first stator 110 and the first rotor 130 form a first motor, the second stator 120 and the second rotor 140 form a second motor, and the first rotor 130 and the second rotor 140 are fixedly connected to the impeller 20. The first motor and the second motor are independently controlled, and can synchronously control the suspension and / or rotation of the impeller 20. The first winding unit 111 and the second winding unit 121 are U-phase winding units, the first winding unit 112 and the second winding unit 122 are W-phase winding units, and the first winding unit 113 and the second winding unit 123 are V-phase winding units. In the figure Indicates N pole, Indicates the S pole.

[0103] When the ventricular assist device 100 is not started, the impeller 20 is attracted by the stator cores in the first stator 110 and the second stator 120, so that the impeller 20 rests on the second cavity wall 32. Since no current is applied to the stator 11, the first position sensor 51 and the second position sensor 52 cannot detect, and the coincidence of the zero point line of the stator 11 and the zero point line of the rotor 13 is unknown. Among them, the zero point line of the stator 11 is the P line, and the zero point line of the rotor 13 is the O line.

[0104] After the control unit 33 receives the start command, the control unit 33 applies the first current to the first winding unit 111 and the first winding unit 114, and applies the first current to the second winding unit 121 and the second winding unit 124 at time T1, so that the first winding unit 111, the first winding unit 114, the second winding unit 121 and the second winding unit 124 exhibit S-pole magnetism, and the position of the rotor 13 and the stator 11 at time T1 Figure 7 As shown. By the principle of opposites attracting each other, the first winding unit 111, the first winding unit 114, the second winding unit 121 and the second winding unit 124 will attract the magnetic blocks with N poles in the first rotor 130 and the second rotor 140, so that the rotor 13 rotates along its circumferential direction, and 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 coincide with each other on the target plane.

[0105] In order to suspend the impeller 20 to the first position, 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 are overlapped on the target plane so that the magnetic blocks 131, 135, 141 and 145 with N-pole magnetic poles are respectively opposite to the first winding unit 111, the first winding unit 114, the second winding unit 121 and the second winding unit 124. At time T2, the control unit 33 applies a second current to the first winding unit 111 and the first winding unit 114 respectively. The second current is opposite to the direction of the first current, so that the first winding unit 111 and the first winding unit 114 show N-pole magnetism. The position of the rotor 13 and the stator 11 at time T2 is as follows: Figure 8 and Fig. 9 The first winding unit 111 and the first winding unit 114 with N-pole magnetism respectively generate axial magnetic thrust F with the magnetic block 131 and the magnetic block 135 with N-pole magnetism, and the magnetic thrust F moves the impeller 20 axially to the first position.

[0106] After the impeller 20 is suspended to the first position, the control unit 33 starts the rotation of the impeller 20. The control unit 33 inputs three-phase alternating currents to the second three-phase winding to drive the second rotor 140 to rotate counterclockwise, wherein each three-phase alternating current is equally separated by 120 degrees through a phase difference. During the rotation of the second rotor 140, the second position sensor 52 detects the magnetic pole angle of the second rotor 140 in real time. If it is detected at time T3 that the magnetic block 134, the magnetic block 144, the magnetic pole 138 and the magnetic block 148 are respectively facing the first winding unit 113, the second winding unit 123, the first winding unit 116 and the second winding unit 126, since the magnetic poles of the magnetic block 134, the magnetic block 144, the magnetic pole 138 and the magnetic block 148 are S poles, the control unit 33 applies the second current of the same magnitude and opposite direction to the first winding unit 113 and the first winding unit 116, respectively, so that the first winding unit 113 and the first winding unit 116 show the magnetism of S pole, the position of the rotor 13 and the stator 11 at time T3 is as follows: Fig.10 and Fig.11 The first winding unit 113 and the first winding unit 116 with S-pole magnetism respectively generate axial magnetic thrust F with the magnetic blocks 134 and 138 with S-pole magnetism, and the magnetic thrust F keeps the impeller 20 suspended in the first position.

[0107] If it is detected at time T4 that the magnetic block 133, the magnetic block 143, the magnetic pole 137 and the magnetic block 147 are respectively facing the first winding unit 112, the second winding unit 122, the first winding unit 115 and the second winding unit 125, since the magnetic poles of the magnetic block 133, the magnetic block 143, the magnetic pole 137 and the magnetic block 147 are N poles, the control unit 33 applies the second current with the same direction and magnitude to the first winding unit 112 and the first winding unit 115 respectively, so that the first winding unit 112 and the first winding unit 115 show N-pole magnetism, the position of the rotor 13 and the stator 11 at time T4 is as follows: Fig.12 and Fig.13 The first winding unit 112 and the first winding unit 115 with N-pole magnetism respectively generate axial magnetic thrust F with the magnetic block 133 and the magnetic block 137 with N-pole magnetism, and the magnetic thrust F keeps the impeller 20 suspended in the first position.

[0108] If it is detected at time T5 that the magnetic block 132, the magnetic block 142, the magnetic pole 136 and the magnetic block 146 are respectively facing the first winding unit, the second winding unit, the first winding unit 114 and the second winding unit 124, since the magnetic poles of the magnetic block 132, the magnetic block 142, the magnetic pole 136 and the magnetic block 146 are S poles, the control unit 33 applies the second current of the same magnitude and opposite direction to the first winding unit and the first winding unit 114, respectively, so that the first winding unit and the first winding unit 114 show the magnetism of S pole, the position of the rotor 13 and the stator 11 at time T5 is as follows: Fig.14 and Fig.15 The first winding unit with S-pole magnetism and the first winding unit 114 respectively generate axial magnetic thrust F with the magnetic blocks 132 and 136 with S-pole magnetism, and the magnetic thrust F keeps the impeller 20 suspended in the first position.

[0109] If it is detected at time T6 that the magnetic block 133, the magnetic block 143, the magnetic pole 137 and the magnetic block 147 are respectively facing the first winding unit 113, the second winding unit 123, the first winding unit 116 and the second winding unit 126, since the magnetic poles of the magnetic block 133, the magnetic block 143, the magnetic pole 137 and the magnetic block 147 are N poles, the control unit 33 applies the second current with the same direction and magnitude to the first winding unit 113 and the first winding unit 116 respectively, so that the first winding unit 113 and the first winding unit 116 show N-pole magnetism, the position of the rotor 13 and the stator 11 at time T6 is as follows: Fig.16 and Fig.17 The first winding unit 113 and the first winding unit 116 with N-pole magnetism respectively generate axial magnetic thrust F with the magnetic block 133 and the magnetic block 137 with N-pole magnetism, and the magnetic thrust F keeps the impeller 20 suspended in the first position.

[0110] If it is detected at time T7 that the magnetic block 134, the magnetic block 144, the magnetic pole 138 and the magnetic block 148 are respectively facing the first winding unit 112, the second winding unit 122, the first winding unit 115 and the second winding unit 125, since the magnetic poles of the magnetic block 134, the magnetic block 144, the magnetic pole 138 and the magnetic block 148 are S poles, the control unit 33 applies the second current of the same magnitude and opposite direction to the first winding unit 112 and the first winding unit 115, respectively, so that the first winding unit 112 and the first winding unit 115 show the magnetism of S pole, the position of the rotor 13 and the stator 11 at time T7 is as follows: Fig.18 and Fig.19 The first winding unit 112 and the first winding unit 115 with S-pole magnetism respectively generate axial magnetic thrust F with the magnetic blocks 134 and 138 with S-pole magnetism, and the magnetic thrust F keeps the impeller 20 suspended in the first position.

[0111] Among them, controlling the rotor 13 to rotate one circle will experience six moments, namely, moment t2, moment t3, moment t4, moment t5, moment t6, and moment t7. If the control unit 33 cyclically controls the current applied to the first stator 110, at each moment, the control unit 33 determines the direction of applying the fourth current to the first winding unit according to the magnetic pole angle of the second rotor 140, thereby realizing stable suspension control of the impeller 20 to rotate at the first position.

[0112] In the present application, the first stator 110 controls the suspension of the impeller 20, and the second stator 120 controls the rotation of the impeller 29, which can avoid the friction between the impeller 20 and the housing assembly when the impeller 20 starts to rotate, and avoid the damage to the inner wall surface of the housing assembly caused by friction, resulting in fluid embolism or condensation. At the same time, the current controlling the suspension of the impeller 20 and the current controlling the rotation of the impeller 20 can be independently decoupled and controlled. The setting of the first motor and the second motor can avoid the continued use of the other motor when one of the motors fails, thereby improving the safety and service life of the motor 10.

[0113] It can be seen that the present application proposes a method for starting a ventricular assist device. At the first moment, a first current is applied to the first stator and the second stator to coincide the zero point line of the stator and the rotor; at the second moment, the first current is stopped from being applied to the second stator, and the second current is applied to the first stator to suspend the rotor; after the rotor is suspended to the first position, a third current is applied to the second stator to control the rotor to rotate at the target speed at the first position. The present application sets two stators. The first stator controls the rotor to suspend to the first position, and the second stator controls the rotor to rotate at the first position, so that the rotor is suspended and then rotates, avoiding the friction resistance when the impeller and the housing slide relative to each other, thereby reducing the thrombus caused by the surface damage of the impeller and the inner wall of the housing, and improving user safety.

[0114] 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.

[0115] 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:

[0116] At a first moment, applying a first current to the first stator and the second stator to make the zero point lines of the stator and the rotor coincide with each other;

[0117] At a second moment, stopping applying the first current to the second stator and applying a second current to the first stator to suspend the rotor;

[0118] After the rotor is suspended to the first position, a third current is applied to the second stator to control the rotor to rotate at the first position.

[0119] For example, the present application also provides a ventricular assist device, the ventricular assist device comprising:

[0120] case;

[0121] an impeller disposed in the housing;

[0122] 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;

[0123] The control unit connected to the motor is used to execute part or all of the steps described in the above method.

[0124] As an example, the present application also provides a medical device, which includes the control unit or ventricular assist device described above.

[0125] 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.

[0126] In the embodiment of the present application, the control unit may also be a chip or a chip system, such as a system on chip (SoC).

[0127] See also Fig. 20 , Fig. 20 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.

[0128] The above program includes instructions for performing the following steps:

[0129] At a first moment, applying a first current to the first stator and the second stator to make the zero point lines of the stator and the rotor coincide with each other;

[0130] At a second moment, stopping applying the first current to the second stator and applying a second current to the first stator to suspend the rotor;

[0131] After the rotor is suspended to the first position, a third current is applied to the second stator to control the rotor to rotate at the first position.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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, which is stored in a memory and includes several instructions for 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, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0146] 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.

[0147] 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 method for activating 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; the method comprises: At a first moment, applying a first current to the first stator and the second stator to make the zero point lines of the stator and the rotor coincide with each other; At a second moment, stopping applying the first current to the second stator and applying a second current to the first stator to suspend the rotor; After the rotor is suspended to the first position, a third current is applied to the second stator to control the rotor to rotate at the first position.

2. The method according to claim 1, characterized in that The direction of the second current is opposite to the direction of the first current.

3. The method according to claim 1 or 2, 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.

4. The method according to claim 3, 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.

5. The method according to claim 4, 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.

6. The method according to claim 5, characterized in that In each of the magnetic block groups, in each of the magnetic block groups, the central angle of the sector ring where the magnetic blocks of the first rotor are located is equal to the central angle of the sector ring where the magnetic blocks of the second rotor are located.

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

8. The method according to claim 3, 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.

9. The method according to claim 5, characterized in that The ventricular assist device also includes 3N first position sensors and 3N second position sensors, each of the first position sensors is arranged between two adjacent first winding units, and the first position sensor is used to measure the suspension height and magnetic pole angle of the first rotor relative to the first winding unit; each of the second position sensors is arranged between two adjacent second winding units, and the second position sensor is used to measure the suspension height and magnetic pole angle of the second rotor relative to the second winding unit.

10. The method according to claim 8, characterized in that The ventricular assist device also includes 3N first position sensors and 3N second position sensors, each of the first position sensors is arranged between two adjacent first winding units, and the first position sensor is used to measure the suspension height and magnetic pole angle of the rotor corresponding to the first winding unit, and each of the second position sensors is arranged between two adjacent second winding units, and the second position sensor is used to measure the suspension height and magnetic pole angle of the rotor relative to the second winding unit.

11. The method according to claim 9 or 10, characterized in that: After applying the third current to the second stator, the method further includes: Acquire a target magnetic pole angle, where the target magnetic pole angle is the magnetic pole angle detected by the second position sensor; Applying a fourth current to the first stator is controlled according to the target magnetic pole angle.

12. The method according to claim 11, 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; 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 applying a first current to the first stator and the second stator to make the zero point line of the stator coincide with the zero point line of the rotor comprises: The first current is applied to the first phase winding unit in the first three-phase winding and the second three-phase winding respectively, so that 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 with each other on a 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 center axis of the first stator and / or the second stator.

13. The method according to claim 11, characterized in that The controlling the application of a fourth current to the first stator according to the target magnetic pole angle comprises: When the target magnetic pole angle is a first angle, the fourth current is applied to a first phase winding unit in the first three-phase winding unit, the first angle being that the first phase winding unit in the first three-phase winding is directly opposite to a target magnetic block in the rotor, and the target magnetic block is a magnetic block whose magnetic pole close to one side of the stator is an N pole or an S pole; When the target magnetic pole angle is a second angle, applying the fourth current to the second phase winding unit in the first three-phase winding unit, and the second angle is that the second phase winding unit in the first three-phase winding is directly opposite to the target magnetic block in the rotor; When the target magnetic pole angle is a third angle, the fourth current is applied to the third phase winding unit in the first three-phase winding unit, and the third angle is that the third phase winding unit in the first three-phase winding is directly opposite to the target magnetic block in the rotor.

14. The method according to claim 13, characterized in that When the magnetic pole of the target magnetic block is the N pole, the current direction of the fourth current is the same as the current direction of the second current; When the magnetic pole of the target magnetic block is the S pole, the current direction of the fourth current is opposite to the current direction of the second current.

15. 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: At a first moment, applying a first current to the first stator and the second stator to make the zero point lines of the stator and the rotor coincide with each other; At a second moment, stopping applying the first current to the second stator and applying a second current to the first stator to suspend the rotor; After the rotor is suspended to the first position, a third current is applied to the second stator to control the rotor to rotate at the first position.

16. 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 configured to execute the steps of the method according to any one of claims 1 to 14.

17. 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 14.

18. 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 14.

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