A right ventricular assist system and a control method of a right ventricular assist device

Abstract

The embodiment of the application provides a right ventricular assist system and a control method of a right ventricular assist device. The right ventricular assist device comprises a blood-out cage, a blood-in cage, a pumping assembly and a driving assembly. The driving assembly, the pumping assembly and the blood-in cage are located in the inferior vena cava, and the blood-out cage is located in the pulmonary artery. The driving assembly drives the pumping assembly to rotate in the clockwise direction, pushes the blood from the blood-in cage into the blood-out cage, and then into the pulmonary artery. The target motor in the driving assembly is a brushless hollow cup motor, which is composed of a rotor and a stator. The angle between the magnetic induction lines of the rotor magnetic field and the stator magnetic field is a fixed angle, which is an angle between 40 degrees and 50 degrees. The controller comprises a level determination module, a current determination module, a current mapping module, a current fusion module, a voltage determination module and a motor control module. By using the embodiment, the control of the right ventricular assist device can be adapted to the real-time change state of the heart.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a right ventricular assist system and a control method for the right ventricular assist device. Background Technology

[0002] A right ventricular assist system (LVAS) is a system used to assist the right ventricle in pumping blood. An LVAS consists of a right ventricular assist device (LVAD) and a controller. The LVAD is implanted inside the patient's heart, while the controller is located outside the patient's body to control the LVAD. The controller monitors the operating parameters of the LVAD and the patient's physiological parameters, and controls the operation of the LVAD.

[0003] Currently, right ventricular assist devices (LVAPs) typically operate according to fixed control parameters set by medical staff. However, the heart is constantly in a state of dynamic change, and controlling LVAPs with fixed parameters makes it difficult for them to adapt to the heart's real-time changes. Summary of the Invention

[0004] The purpose of this application is to provide a control method for a right ventricular assist system and a right ventricular assist device, so as to achieve adaptive control of the right ventricular assist device to the real-time changing state of the heart. The specific technical solution is as follows:

[0005] In a first aspect, embodiments of this application provide a right ventricular assist system, which includes a right ventricular assist device and a controller;

[0006] The right ventricular assist device includes a bleeding cage, an inlet cage, a pumping assembly, and a driving assembly. The driving assembly, the pumping assembly, and the inlet cage are located in the inferior vena cava, and the bleeding cage is located in the pulmonary artery. The driving assembly drives the pumping assembly to rotate clockwise, pushing blood from the inlet cage into the bleeding cage until it is discharged into the pulmonary artery.

[0007] The target motor in the drive assembly is a brushless coreless motor, which is composed of a rotor and a stator; the angle between the magnetic field lines of the rotor and the magnetic field lines of the stator is a fixed angle, which is between 40 and 50 degrees.

[0008] The controller includes:

[0009] The grade determination module is used to determine the current change curve characterizing the current fluctuation of the target motor and the pressure change curve characterizing the aortic pressure fluctuation of the target object. Based on the current change curve and the pressure change curve, the target grade characterizing the right ventricular recovery degree of the target object is determined, wherein the target object is the object to which the ventricular assist device is implanted.

[0010] The current determination module is used to acquire the current current of the target motor and, based on the target level, determine the motor current suitable for the current right ventricular recovery level of the target object as the expected current.

[0011] A current mapping module is used to determine a first mapping component and a second mapping component of the current current of the target motor. The first mapping component is the current component mapped to the first coordinate axis in a preset coordinate system, and the second mapping component is the current component mapped to the second coordinate axis in the preset coordinate system. The preset coordinate system is a coordinate system constructed with the rotor center as the origin, the direction of the rotor magnetic field as the first coordinate axis, and the direction perpendicular to the rotor magnetic field as the second coordinate axis.

[0012] A current fusion module is used to fuse the first mapping component and the second mapping component to obtain the target current;

[0013] The voltage determination module is used to calculate the target current difference between the desired current and the target current, determine the voltage corresponding to the target current difference according to a preset mapping relationship between current difference and voltage, and determine the control voltage of the target motor based on the determined voltage.

[0014] The motor control module is used to acquire the current magnetic field direction of the rotor, determine the target direction of the stator's clockwise magnetic field rotation along the current magnetic field direction, determine the coil conduction sequence of the stator corresponding to the target magnetic field rotation direction, and conduct the stator coils according to the coil conduction sequence and control voltage to control the target motor.

[0015] In one embodiment of this application, the aforementioned level determination module is specifically used to input the current change curve and the pressure change curve into a pre-trained level prediction model to obtain the level output by the level prediction model, which serves as the target level characterizing the degree of right ventricular recovery of the target object.

[0016] The grade prediction model is a model trained on an initial neural network using sample current change curves and sample pressure change curves as training samples and the actual grade representing the right ventricular recovery degree of the sample object as the training benchmark. The sample current change curve is a current change curve representing the fluctuation of the current of the ventricular assist device implanted in the sample object, and the sample pressure change curve is a pressure change curve representing the fluctuation of the aortic pressure of the sample object.

[0017] In one embodiment of this application, the aforementioned current determination module is specifically used to determine the rotational speed corresponding to the target level as the desired rotational speed based on a preset correspondence between the level and the rotational speed; obtain the current rotational speed of the target motor; calculate the target rotational speed difference between the desired rotational speed and the current rotational speed; and map the target rotational speed difference according to a preset mapping relationship between the rotational speed difference and the current to obtain a current adapted to the current right ventricular recovery level of the target object as the desired current.

[0018] In one embodiment of this application, the motor control module is specifically configured to iteratively obtain the current magnetic field direction of the rotor as a reference direction, determine a preset sub-magnetic field direction that is closest to the reference direction in a clockwise direction, and determine the preset sub-magnetic field direction determined in each iteration as the target direction of magnetic field rotation; determine the conduction sequence of the stator coils corresponding to the target direction of magnetic field rotation according to the preset relationship between the magnetic field rotation direction and the coil conduction sequence; and conduct the stator coils according to the conduction sequence and the control voltage to control the target motor.

[0019] In one embodiment of this application, the controller further includes an angle prediction module;

[0020] The angle prediction module is used to predict the parameter value of the angle between the rotor magnetic field lines and the stator magnetic field lines based on the first mapping component and the second mapping component before the current fusion module, and use it as the predicted angle; if the predicted angle is consistent with the fixed angle, the current fusion module is triggered.

[0021] Secondly, embodiments of this application provide a control method for a right ventricular assist device, the method being applied to a controller in a right ventricular assist system, the right ventricular assist system further including a right ventricular assist device;

[0022] The right ventricular assist device includes a bleeding cage, an inlet cage, a pumping assembly, and a driving assembly. The driving assembly, the pumping assembly, and the inlet cage are located in the inferior vena cava, and the bleeding cage is located in the pulmonary artery. The driving assembly drives the pumping assembly to rotate clockwise, pushing blood from the inlet cage into the bleeding cage until it is discharged into the pulmonary artery.

[0023] The target motor in the drive assembly is a brushless coreless motor, which is composed of a rotor and a stator; the angle between the magnetic field lines of the rotor and the magnetic field lines of the stator is a fixed angle, which is between 40 and 50 degrees.

[0024] The method includes:

[0025] A current change curve characterizing the current fluctuation of the target motor is determined, and a pressure change curve characterizing the aortic pressure fluctuation of the target object is determined. Based on the current change curve and the pressure change curve, a target level characterizing the degree of right ventricular recovery of the target object is determined, wherein the target object is the object to which the ventricular assist device is implanted.

[0026] The current current of the target motor is obtained, and based on the target level, the motor current suitable for the current right ventricular recovery level of the target object is determined as the expected current;

[0027] Determine the first and second mapping components of the current current of the target motor, wherein the first mapping component is the current component mapped to the first coordinate axis in the preset coordinate system, and the second mapping component is the current component mapped to the second coordinate axis in the preset coordinate system. The preset coordinate system is a coordinate system constructed with the rotor center as the origin, the direction of the rotor magnetic field as the first coordinate axis, and the direction perpendicular to the rotor magnetic field as the second coordinate axis.

[0028] The first and second mapping components are fused to obtain the target current;

[0029] Calculate the target current difference between the desired current and the target current; determine the voltage corresponding to the target current difference according to the preset mapping relationship between current difference and voltage; and determine the control voltage of the target motor based on the determined voltage.

[0030] Obtain the current magnetic field direction of the rotor, determine the target direction of the stator's clockwise magnetic field rotation along the current magnetic field direction; determine the coil conduction sequence of the stator corresponding to the target magnetic field rotation direction; and conduct the stator coils according to the coil conduction sequence and control voltage to control the target motor.

[0031] In one embodiment of this application, determining the target level characterizing the degree of right ventricular recovery of the target object based on the current change curve and the pressure change curve includes:

[0032] The current change curve and pressure change curve are input into a pre-trained grading prediction model to obtain the grading level output by the grading prediction model, which serves as the target grading level characterizing the right ventricular recovery degree of the target object. The grading prediction model is a model trained on an initial neural network using sample current change curves and sample pressure change curves as training samples and the actual grading level characterizing the right ventricular recovery degree of the sample object as the training benchmark. The sample current change curve is the current change curve characterizing the fluctuations in the ventricular assist device implanted in the sample object, and the sample pressure change curve is the pressure change curve characterizing the fluctuations in the aortic pressure of the sample object.

[0033] In one embodiment of this application, determining the motor current, as the desired current, based on the target level and applicable to the current right ventricular recovery degree of the target object, includes:

[0034] Based on the preset correspondence between the level and the rotation speed, the rotation speed corresponding to the target level is determined as the desired rotation speed;

[0035] Obtain the current speed of the target motor, and calculate the target speed difference between the desired speed and the current speed;

[0036] According to the preset mapping relationship between rotational speed difference and current, the target rotational speed difference is mapped to obtain a current that is adapted to the current right ventricular recovery level of the target object, which is taken as the desired current.

[0037] In one embodiment of this application, obtaining the current magnetic field direction of the rotor and determining the target direction of clockwise magnetic field rotation of the stator along the current magnetic field direction includes:

[0038] The current magnetic field direction of the rotor is obtained through iterative execution and used as a reference direction. A preset sub-magnetic field direction that is closest to the reference direction and is clockwise along the reference direction is determined. The preset sub-magnetic field direction determined by each iteration is determined as the target direction of magnetic field rotation.

[0039] The determination of the stator coil conduction sequence corresponding to the target direction of the magnetic field rotation includes:

[0040] Based on the preset relationship between the magnetic field rotation direction and the coil conduction sequence, the conduction sequence of the stator coil corresponding to the target magnetic field rotation direction is determined.

[0041] In one embodiment of this application, before fusing the first mapping component and the second mapping component to obtain the target current, the method further includes:

[0042] Based on the first mapping component and the second mapping component, the parameter value of the angle between the rotor magnetic field lines and the stator magnetic field lines is predicted as the predicted angle; if the predicted angle is consistent with the fixed angle, the first mapping component and the second mapping component are fused to obtain the target current.

[0043] As can be seen from the above, in the right ventricular assist system provided in this embodiment, the controller in the right ventricular assist system controls the target motor according to the control voltage. The control voltage is calculated based on the target current difference between the desired current and the target current. The desired current is determined based on the target level characterizing the current degree of right ventricular recovery and is a current value adapted to the current degree of right ventricular recovery. Therefore, the aforementioned target current difference reflects the gap between the current real-time current and the desired current adapted to the current degree of right ventricular recovery. The control voltage calculated using the aforementioned target current difference can adapt to the current degree of right ventricular recovery. The target motor controlled according to the aforementioned control voltage can make the motor control adaptive to the current degree of right ventricular recovery of the target object, thereby achieving adaptive control.

[0044] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0046] Figure 1a A schematic diagram of a right ventricular assist system provided in an embodiment of this application;

[0047] Figure 1b A schematic diagram of the structure of a right ventricular assist device provided in an embodiment of this application;

[0048] Figure 1c This is a schematic diagram of the structure of a target motor provided in an embodiment of this application;

[0049] Figure 2 This is a schematic diagram of the structure of a controller provided in an embodiment of this application;

[0050] Figure 3 A schematic diagram of a coordinate system provided for an embodiment of this application;

[0051] Figure 4 A schematic diagram illustrating a predicted angle provided in an embodiment of this application;

[0052] Figure 5 This is a flowchart illustrating a control method for a right ventricular assist device provided in an embodiment of this application. Detailed Implementation

[0053] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0054] First, combined Figure 1a The overall structure of the right ventricular assist system according to the embodiments of this application will be described.

[0055] Figure 1a A schematic diagram of the overall structure of a right ventricular assist system is shown, including the right ventricular assist device and a controller. The right ventricular assist device is used to assist the patient's heart in pumping blood, and the controller is used to detect the operating parameters of the right ventricular assist device and the physiological parameters of the target patient, and to control the operation of the right ventricular assist device.

[0056] The aforementioned right ventricular assist system may also include a flushing device for flushing the area surrounding the right ventricular assist device to prevent blood from entering the right ventricular assist device.

[0057] Combination Figure 1b The right ventricular assist device is described below. The right ventricular assist device includes a blood inlet cage 101, a blood outlet cage 102, a pumping assembly 103, and a drive assembly 104.

[0058] After the right ventricular assist device is implanted in the heart, the drive assembly 104, the pumping assembly 103, and the blood inlet cage 102 are located in the inferior vena cava, and the blood outlet cage 101 is located in the pulmonary artery.

[0059] The drive component drives the pumping component to rotate clockwise, pushing blood from the inlet cage into the outlet cage until it is discharged into the pulmonary artery.

[0060] In the system provided in this application, the target motor in the drive assembly of the right ventricular assist device is a brushless coreless motor. This target motor consists of a stator and a rotor, and a simplified structural diagram of the target motor is shown below. Figure 1c As shown. In Figure 1c The rotor consists of two layers: an outer stator made of coils and an inner rotor. The core component of the rotor is the rotor permanent magnet, which has N and S poles.

[0061] In the system provided in this application embodiment, the adaptability improvement of the brushless coreless motor for right ventricular assist devices is as follows: the angle between the rotor magnetic field lines and the stator magnetic field lines is a fixed angle, and this fixed angle is between 40 degrees and 50 degrees. For example, the fixed angle can be 40 degrees, 41 degrees, ... 45 degrees, 46 degrees, ... 50 degrees.

[0062] The angle between the magnetic field lines of the rotor and the magnetic field lines of the stator indicates the relative position between the rotor and the stator. When the angle is fixed, it means that the relative position between the rotor and the stator is constant.

[0063] The improvement to the brushless coreless motor in this application can be caused by a combination of a specific magnetization method for the rotor permanent magnet and a specific winding method for the stator coil. For example, the rotor permanent magnet is radially magnetized and the stator coil is wound with a specific slant angle, so that the angle between the rotor magnetic field lines and the stator magnetic field lines is a fixed angle between 40 and 50 degrees.

[0064] The aforementioned controller is used to control the target motor of the right ventricular assist device. The following is in conjunction with... Figure 2 The structure of the controller is described. Based on this, see [link / reference]. Figure 2 , Figure 2 A schematic diagram of the structure of the first controller provided in the embodiments of this application includes 201-206.

[0065] The grade determination module 201 is used to determine the current change curve characterizing the current fluctuation of the target motor and the pressure change curve characterizing the aortic pressure fluctuation of the target object. Based on the current change curve and the pressure change curve, the target grade characterizing the degree of right ventricular recovery of the target object is determined.

[0066] The target group is the recipient of the right ventricular assist device.

[0067] The aforementioned current variation curve is used to characterize the current fluctuations of the target motor, and the pressure variation curve is used to characterize the aortic pressure fluctuations of the target object.

[0068] The aforementioned current change curves and pressure change curves can be curves extending forward from the current moment over a preset time period.

[0069] When the right ventricular assist device is running, the controller can determine the current and aortic pressure at each moment. The controller can store the current and aortic pressure at each moment in a memory. Then, the curve determination module can read the current and aortic pressure within a preset time period from the memory and generate current change curves and pressure change curves in chronological order. The controller can also pre-generate current change curves and pressure change curves, so that the curve determination module can directly read the current change curves and pressure change curves from the memory.

[0070] The aforementioned target levels characterize the degree of right ventricular recovery in the target individual. Ventricular assist devices (VADs) are primarily designed for heart failure patients, especially those with insufficient right ventricular pumping capacity. For these patients, the main purpose is to assist right ventricular pumping to restore right ventricular function. Therefore, as the VAD is used, the state of the right ventricle changes accordingly, and the right ventricular's own pumping function gradually recovers. Thus, the aforementioned target levels effectively characterize the current cardiac performance of the target individual.

[0071] The relationship between the degree of right ventricular recovery and its grade can be predetermined. The better the right ventricular recovery, the lower the corresponding grade; the worse the right ventricular recovery, the higher the corresponding grade.

[0072] In determining the target level, one implementation method is to determine the corresponding right ventricular pressure change curve based on the current change curve and the pressure change curve, according to a preset correspondence between current-aortic pressure-right ventricular pressure; calculate the similarity between the determined right ventricular pressure change curve and the preset right ventricular pressure change curve; and convert the similarity into the target level according to the preset correspondence between similarity and level.

[0073] The aforementioned preset right ventricular pressure change curve can be the average change curve of the right ventricular pressure change curve in normal individuals. The aforementioned preset right ventricular pressure change curve is used to characterize the change curve of normal right ventricular pressure.

[0074] A higher similarity indicates a greater similarity between the currently determined right ventricular pressure change curve and the preset right ventricular pressure change curve, meaning a better degree of right ventricular recovery for the current target subject and a lower target level.

[0075] In another implementation of determining the target level, the current change curve and the pressure change curve can be input into a pre-trained level prediction model to obtain the level output by the level prediction model, which can be used as the target level characterizing the degree of right ventricular recovery of the target object.

[0076] The aforementioned grade prediction model is: a model obtained by training an initial neural network using sample current change curves and sample pressure change curves as training samples and the actual grade representing the right ventricular recovery degree of the sample object as the training benchmark, and used to determine the grade representing the right ventricular recovery degree of the object.

[0077] The above sample current change curves represent the current fluctuations of the implanted right ventricular assist device in the sample subjects. The above sample pressure change curves represent the pressure fluctuations of the aortic pressure in the sample subjects.

[0078] Because a large number of training samples are used to train the grade prediction model, the trained grade prediction model can learn the characteristics of determining the degree of right ventricular recovery based on the current change curve and the pressure change curve. Therefore, by using the above grade prediction model, an accurate grade representing the degree of right ventricular recovery of the current target object can be obtained.

[0079] The current determination module 202 is used to acquire the current current of the target motor and, based on the target level, determine the motor current suitable for the current right ventricular recovery level of the target object as the expected current.

[0080] The desired current is used to characterize the current applicable to the current degree of right ventricular recovery in the target subject. In determining the desired current, in one implementation, the current corresponding to the target level can be determined according to a preset correspondence between levels and currents, and this current is used as the desired current.

[0081] In another implementation of determining the desired current, the rotational speed corresponding to the target level can be determined based on a preset correspondence between the level and the rotational speed, and this speed can be taken as the desired speed. The current rotational speed of the target motor can be obtained, and the target speed difference between the desired speed and the current speed can be calculated. The target speed difference can be mapped according to a preset mapping relationship between the speed difference and the current to obtain a current that is suitable for the current right ventricular recovery level of the target object, which is taken as the desired current.

[0082] In this embodiment, the desired rotational speed is determined first, the target rotational speed difference is calculated based on the desired rotational speed, and then the desired current is determined based on the target rotational speed difference. By following this speed-current order relationship, the determined desired current is related to the current speed, thereby improving the accuracy of the desired current.

[0083] The current mapping module 203 is used to determine the first mapping component and the second mapping component of the current current of the target motor.

[0084] The current current mentioned above refers to the current currently being used by the target motor.

[0085] The first mapping component is the current component mapped to the first coordinate axis in the preset coordinate system. The second mapping component is the current component mapped to the second coordinate axis in the preset coordinate system.

[0086] The aforementioned preset coordinate system is a coordinate system constructed with the rotor center as the origin, the direction of the rotor's magnetic field as the first coordinate axis, and the direction perpendicular to the rotor's magnetic field as the second coordinate axis. Figure 3 Taking the above-mentioned preset coordinate system as an example, let's explain it. Figure 3 Point O is the rotor center, which is also the origin of the coordinate system. The direction of the d-axis is the direction of the rotor magnetic field, which is also the first coordinate axis. The direction of the q-axis is perpendicular to the direction of the rotor magnetic field.

[0087] The current current is currently measured in the abc-axis coordinate system corresponding to the stator coils. After the motor starts, the rotor motion causes the current value in the abc-axis coordinate system to change dynamically in real time, resulting in complex parameters and a large computational load. Therefore, to efficiently utilize computational resources, the current current is mapped to the aforementioned preset coordinate system. Since this preset coordinate system is established with the rotor center as the origin, mapping the current current to this coordinate system decouples various dynamic changes in the current. Control parameters are then calculated based on the decoupled mapped components, thereby achieving efficient utilization of computational resources.

[0088] In determining the first mapping component and the second mapping component, in one embodiment, the current component of the first coordinate axis corresponding to the current current can be determined as the first mapping component according to the mapping relationship between the coordinate system corresponding to the current current and the preset coordinate system, and the current component of the second coordinate axis corresponding to the current current can be determined as the second mapping component.

[0089] The current fusion module 204 is used to fuse the first mapping component and the second mapping component to obtain the target current.

[0090] When fusing the above current components, the vector sum of the first and second current components can be calculated, and the calculated vector sum can be determined as the target current.

[0091] Because the angle between the rotor magnetic field lines and the stator magnetic field lines is a fixed angle between 40 and 50 degrees, this fixed angle indicates that there is always magnetic field cutting between the rotor and stator magnetic field lines. In this situation, through extensive simulation experiments and experimental data, the inventors discovered that the direction of the optimal torque generated for the rotor is not only related to the perpendicular direction of the rotor magnetic field, but also to the direction of the rotor magnetic field itself. Therefore, if traditional motor control methods are still used, the generated torque will not be the optimal torque, and may even affect rotor rotation.

[0092] Based on the above analysis, since the first mapping component is related to the direction of the rotor magnetic field and the second mapping component is related to the direction perpendicular to the direction of the rotor magnetic field, the target current obtained by fusing the first and second mapping components can more accurately reflect the information of the optimal torque direction of the rotor, thereby realizing high-precision motor control.

[0093] The voltage determination module 205 is used to calculate the target current difference between the desired current and the target current, determine the voltage corresponding to the target current difference according to the preset mapping relationship between current difference and voltage, and determine the control voltage of the target motor based on the determined voltage.

[0094] Since the target current is in a coordinate system with the rotor center point as the origin, and the control voltage controls the conduction of the stator coils, the control voltage needs to be related to the stator coordinate system. Therefore, a coordinate system transformation is required for the determined voltage. Based on this, the determined voltage can be transformed according to the correspondence between the rotor coordinate system and the stator coordinate system, and the transformed voltage can be determined as the control voltage.

[0095] When performing the conversion, you can use the following formula:

[0096] ;

[0097] in, Indicates the first voltage component. Indicates the second voltage component. This indicates the determined voltage. This represents a fixed angle. The first voltage component mentioned above... Second voltage component As the control voltage for the motor.

[0098] The motor control module 206 is used to obtain the current magnetic field direction of the rotor, determine the target direction of the stator to rotate clockwise along the current magnetic field direction, determine the coil conduction sequence of the stator corresponding to the target direction of magnetic field rotation, and conduct the stator coils according to the coil conduction sequence and control voltage to control the target motor.

[0099] When the motor rotates, the rotor is constantly rotating, and the direction of the rotor's magnetic field is also constantly changing. The current magnetic field direction reflects the rotor's current magnetic field direction. The current magnetic field direction of the rotor can be collected by a position sensor, which is used to collect the rotor's current position; the position indicates the magnetic field direction.

[0100] Right ventricular assist devices need to generate thrust to push blood into the pulmonary artery. Therefore, the impeller in the pumping assembly of the right ventricular assist device needs to rotate clockwise. Since the pumping assembly is driven by the drive assembly, the rotor of the motor that drives the pumping assembly also needs to rotate clockwise. The rotor is driven by the stator, so the stator magnetic field rotates clockwise.

[0101] In determining the target direction of the magnetic field rotation corresponding to the stator, in one embodiment, the current magnetic field direction of the rotor can be obtained iteratively as a reference direction, and the clockwise direction along the reference direction and the preset stator magnetic field direction closest to the reference direction can be determined. The preset stator magnetic field direction determined in each iteration is then determined as the target direction of the magnetic field rotation.

[0102] Specifically, in this embodiment, multiple stator magnetic field directions can be predetermined. In the current iteration, the direction closest to the reference direction along the clockwise direction can be determined from the multiple predetermined stator magnetic field directions as the predetermined stator magnetic field direction determined in the current iteration.

[0103] The conduction sequence of the stator coils corresponds to the rotation direction of the stator's magnetic field. Based on this, the above correspondence can be pre-constructed. Based on the preset relationship between the rotation direction of the magnetic field and the conduction sequence of the coils, the conduction sequence of the stator coils corresponding to the target rotation direction of the magnetic field can be determined.

[0104] According to the above coil conduction sequence and control voltage, the stator coil of the motor is turned on, so that the stator coil conducts in the above coil conduction sequence. Since the coil conduction sequence corresponds to the clockwise direction of the magnetic field rotation target, after the coil is turned on, the rotation direction of the stator magnetic field is clockwise. Under the drive of the stator magnetic field, the rotor also rotates in the clockwise direction, thereby realizing the motor control of the right ventricular assist device.

[0105] As can be seen from the above, in the right ventricular assist system provided in this embodiment, the controller in the right ventricular assist system controls the target motor according to the control voltage. The control voltage is calculated based on the target current difference between the desired current and the target current. The desired current is determined based on the target level characterizing the current degree of right ventricular recovery and is a current value adapted to the current degree of right ventricular recovery. Therefore, the aforementioned target current difference reflects the gap between the current real-time current and the desired current adapted to the current degree of right ventricular recovery. The control voltage calculated using the aforementioned target current difference can adapt to the current degree of right ventricular recovery. The target motor controlled according to the aforementioned control voltage can make the motor control adaptive to the current degree of right ventricular recovery of the target object, thereby achieving adaptive control.

[0106] Furthermore, since the current control component in the controller integrates a first mapping component and a second mapping component, with the first mapping component reflecting information about the direction of the rotor magnetic field and the second mapping component reflecting information about the direction perpendicular to the rotor magnetic field, the target current obtained by fusing the first and second mapping components can fully reflect information about both the direction of the rotor magnetic field and the direction perpendicular to it. Also, since the angle between the rotor magnetic field lines and the stator magnetic field lines is a fixed angle between 40 and 50 degrees, the direction of the optimal rotor torque is related to both the direction of the rotor magnetic field and the direction perpendicular to it. Therefore, the target current can accurately reflect the direction information of the optimal rotor torque. Using this target current to determine the control voltage, and then controlling the right ventricular assist device, high-precision control of the right ventricular assist device can be achieved.

[0107] In the foregoing Figure 2 The system shown may also include an angle prediction module. This angle prediction module, prior to the current fusion module, predicts the parameter value of the angle between the rotor magnetic field lines and the stator magnetic field lines based on the first and second mapping components, as the predicted angle; if the predicted angle matches the fixed angle, the aforementioned... Figure 2 If the current fusion module is not selected, the current calculation module is triggered.

[0108] The fixed angle mentioned above is the actual parameter value of the angle between the rotor magnetic field lines and the stator magnetic field lines, while the predicted angle in this embodiment is an estimated parameter value.

[0109] The predicted angle mentioned above is obtained using current real-time data. When the predicted angle matches the fixed angle, it indicates that the accuracy of the current current being collected is high; when the predicted angle does not match the fixed angle, it indicates that the accuracy of the current current being collected is low.

[0110] Combination Figure 4 The above-mentioned prediction angles will be explained. Figure 4 I located on the d-axis d Represents the first mapped component, located on the q-axis, I. q Indicates the second mapping component; with I d I q Two sides of the triangle are represented by the dashed line I. The third side of the triangle is represented by the dashed line I. b I b The direction is the direction of the stator magnetic field lines, I d The direction in which the magnetic field lines of the rotor are located is the direction in which I can be calculated. q with I dThe ratio between the two is the tan function value of the predicted angle. Using trigonometric relationships, the angle between the two angles can be predicted as the predicted angle.

[0111] When determining whether the predicted angle is consistent with the fixed angle, it can be determined whether the predicted angle and the fixed angle are the same. Alternatively, the predicted angle can be extended forward and backward by a preset prediction angle error as the center to obtain the prediction angle range. Then, it can be determined whether the fixed angle is within the above prediction angle range. If yes, it means that the predicted angle and the fixed angle are consistent; if no, it means that the predicted angle and the fixed angle are inconsistent.

[0112] When the predicted angle differs from the fixed angle, the current calculation module is triggered. The current calculation module includes a current prediction submodule and a current determination submodule. Specifically:

[0113] The current prediction submodule is used to predict the current component of the current mapped onto the first coordinate axis based on the second mapping component and a fixed angle, as the first prediction component, and to predict the current component of the current mapped onto the second coordinate axis based on the first mapping component and a fixed angle, as the second prediction component.

[0114] When the predicted angle differs from the fixed angle, it indicates that the accuracy of the currently acquired current is low. Naturally, there will be a current error between the first and second acquired current components determined based on the acquired current. In this case, the first and second mapped components are decoupled, and current prediction is performed separately based on the current components. This reduces the problem of low accuracy in determining the target current caused by the acquisition current error.

[0115] When predicting current components, based on a preset trigonometric function relationship, the current component corresponding to the first coordinate axis can be predicted as the first predicted component, with the second mapping component as the reference. Then, based on the first mapping component, the current component corresponding to the second coordinate axis can be predicted as the second predicted component.

[0116] For example, the second mapping component can be calculated with The product between them is used as the first predicted component, and the first mapped component is calculated with... The product between them is used as the second prediction component.

[0117] The current determination submodule is used to determine the target current based on the first prediction component and the second prediction component.

[0118] Since the target current is obtained by fusing the first prediction component and the second prediction component, which are obtained by decoupling the mapped current component and predicting based on the two mapped components and a fixed angle, the obtained prediction component has higher accuracy than the initial current classification. Therefore, the target current determined based on the above prediction component has higher accuracy.

[0119] In determining the target current, in one implementation, the vector sum between the first predicted component and the second predicted component can be calculated, and the calculated value can be determined as the target current.

[0120] In another implementation of determining the target current, the first mapping component can be updated based on the first predicted component, and the updated first mapping component can be determined as the first updated component. The second mapping component can be updated based on the second predicted component, and the updated second mapping component can be determined as the second updated component. The first predicted component and the second predicted component are fused to obtain the first fused current. The first updated component and the second current component are fused to obtain the second fused current. The first fused current and the second fused current are fused, and the fused current is determined as the target current.

[0121] When updating the first / second mapping component based on the first / second predicted component, the average value between the first / second predicted component and the first / second mapping component can be calculated, and the calculated average value can be determined as the first / second updated component.

[0122] When determining the first / second fusion current, the vector sum between the current components used can be calculated, and the calculated vector sum can be used as the first / second fusion current.

[0123] When merging the first merging current and the second merging current, the average value between the two merging currents can be calculated, and the calculated value can be determined as the target current.

[0124] Since the updated component is obtained by updating the mapped component based on the predicted component, and combines the information of the two current components, the information reflected by the determined updated component is richer. Therefore, the second fused current determined based on the updated component reflects richer current information, while the first fused current is obtained by fusing the predicted components, and the accuracy of the first fused current is more ideal. Thus, fusing the above two types of fused current can further improve the accuracy of the target current.

[0125] Corresponding to the right ventricular assist system described above, this application also provides a control method for a right ventricular assist device.

[0126] See Figure 5 , Figure 5A control method for a right ventricular assist device is provided in this application embodiment. The method is applied to a controller in a right ventricular assist system, which further includes a right ventricular assist device.

[0127] The right ventricular assist device includes a bleeding cage, an inlet cage, a pumping assembly, and a driving assembly. The driving assembly, the pumping assembly, and the inlet cage are located in the inferior vena cava, and the bleeding cage is located in the pulmonary artery. The driving assembly drives the pumping assembly to rotate clockwise, pushing blood from the inlet cage into the bleeding cage until it is discharged into the pulmonary artery.

[0128] The target motor in the drive assembly is a brushless coreless motor, which is composed of a rotor and a stator; the angle between the magnetic field lines of the rotor and the magnetic field lines of the stator is a fixed angle, which is between 40 and 50 degrees.

[0129] The method includes:

[0130] Step S501: Determine the current change curve characterizing the current fluctuation of the target motor, and determine the pressure change curve characterizing the aortic pressure fluctuation of the target object. Based on the current change curve and the pressure change curve, determine the target level characterizing the degree of right ventricular recovery of the target object, wherein the target object is the object to which the ventricular assist device is implanted.

[0131] Step S502: Obtain the current current of the target motor, and based on the target level, determine the motor current suitable for the current right ventricular recovery level of the target object as the expected current;

[0132] Step S503: Determine the first mapping component and the second mapping component of the current current of the target motor.

[0133] Wherein, the first mapping component is: the current component of the current mapped to the first coordinate axis in the preset coordinate system, and the second mapping component is: the current component of the current mapped to the second coordinate axis in the preset coordinate system. The preset coordinate system is: a coordinate system constructed with the rotor center as the origin, the direction of the rotor magnetic field as the first coordinate axis, and the direction perpendicular to the rotor magnetic field as the second coordinate axis.

[0134] Step S504: Fuse the first mapping component and the second mapping component to obtain the target current;

[0135] Step S505: Calculate the target current difference between the desired current and the target current, determine the voltage corresponding to the target current difference according to the preset mapping relationship between current difference and voltage, and determine the control voltage of the target motor based on the determined voltage;

[0136] Step S506: Obtain the current magnetic field direction of the rotor, determine the target direction of the stator's clockwise magnetic field rotation along the current magnetic field direction; determine the coil conduction sequence of the stator corresponding to the target magnetic field rotation direction; conduct the stator coils according to the coil conduction sequence and control voltage to control the target motor.

[0137] In one embodiment of this application, the step S501 above, which determines the target level characterizing the degree of right ventricular recovery of the target object based on the current change curve and the pressure change curve, includes:

[0138] The current change curve and pressure change curve are input into a pre-trained grading prediction model to obtain the grading level output by the grading prediction model, which serves as the target grading level characterizing the right ventricular recovery degree of the target object. The grading prediction model is a model trained on an initial neural network using sample current change curves and sample pressure change curves as training samples and the actual grading level characterizing the right ventricular recovery degree of the sample object as the training benchmark. The sample current change curve is the current change curve characterizing the fluctuations in the ventricular assist device implanted in the sample object, and the sample pressure change curve is the pressure change curve characterizing the fluctuations in the aortic pressure of the sample object.

[0139] In one embodiment of this application, step S502 above, which determines the motor current applicable to the current right ventricular recovery level of the target object as the desired current based on the target level, includes:

[0140] Based on the preset correspondence between the level and the rotation speed, the rotation speed corresponding to the target level is determined as the desired rotation speed;

[0141] Obtain the current speed of the target motor, and calculate the target speed difference between the desired speed and the current speed;

[0142] According to the preset mapping relationship between rotational speed difference and current, the target rotational speed difference is mapped to obtain a current that is adapted to the current right ventricular recovery level of the target object, which is taken as the desired current.

[0143] In one embodiment of this application, step S506 above, which involves obtaining the current magnetic field direction of the rotor and determining the target direction for the stator to rotate clockwise along the current magnetic field direction, includes:

[0144] The current magnetic field direction of the rotor is obtained through iterative execution and used as a reference direction. A preset sub-magnetic field direction that is closest to the reference direction and is clockwise along the reference direction is determined. The preset sub-magnetic field direction determined by each iteration is determined as the target direction of magnetic field rotation.

[0145] The determination of the stator coil conduction sequence corresponding to the target direction of the magnetic field rotation includes:

[0146] Based on the preset relationship between the magnetic field rotation direction and the coil conduction sequence, the conduction sequence of the stator coil corresponding to the target magnetic field rotation direction is determined.

[0147] In one embodiment of this application, before fusing the first mapping component and the second mapping component in step S504 to obtain the target current, the method further includes:

[0148] Based on the first mapping component and the second mapping component, the parameter value of the angle between the rotor magnetic field lines and the stator magnetic field lines is predicted as the predicted angle; if the predicted angle is consistent with the fixed angle, the first mapping component and the second mapping component are fused to obtain the target current.

[0149] As can be seen from the above, in the right ventricular assist system provided in this embodiment, the controller in the right ventricular assist system controls the target motor according to the control voltage. The control voltage is calculated based on the target current difference between the desired current and the target current. The desired current is determined based on the target level characterizing the current degree of right ventricular recovery and is a current value adapted to the current degree of right ventricular recovery. Therefore, the aforementioned target current difference reflects the gap between the current real-time current and the desired current adapted to the current degree of right ventricular recovery. The control voltage calculated using the aforementioned target current difference can adapt to the current degree of right ventricular recovery. The target motor controlled according to the aforementioned control voltage can make the motor control adaptive to the current degree of right ventricular recovery of the target object, thereby achieving adaptive control.

[0150] Furthermore, since the current control component in the controller integrates a first mapping component and a second mapping component, with the first mapping component reflecting information about the direction of the rotor magnetic field and the second mapping component reflecting information about the direction perpendicular to the rotor magnetic field, the target current obtained by fusing the first and second mapping components can fully reflect information about both the direction of the rotor magnetic field and the direction perpendicular to it. Also, since the angle between the rotor magnetic field lines and the stator magnetic field lines is a fixed angle between 40 and 50 degrees, the direction of the optimal rotor torque is related to both the direction of the rotor magnetic field and the direction perpendicular to it. Therefore, the target current can accurately reflect the direction information of the optimal rotor torque. Using this target current to determine the control voltage, and then controlling the right ventricular assist device, high-precision control of the right ventricular assist device can be achieved.

[0151] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (SSD)).

[0152] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0153] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the method, computer-readable storage medium, and computer program product embodiments are basically similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0154] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A right ventricular assist system, characterized in that, The right ventricular assist system includes a right ventricular assist device and a controller; The right ventricular assist device includes a bleeding cage, an inlet cage, a pumping assembly, and a driving assembly. The driving assembly, the pumping assembly, and the inlet cage are located in the inferior vena cava, and the bleeding cage is located in the pulmonary artery. The driving assembly drives the pumping assembly to rotate clockwise, pushing blood from the inlet cage into the bleeding cage until it is discharged into the pulmonary artery. The target motor in the drive assembly is a brushless coreless motor, which is composed of a rotor and a stator; the angle between the magnetic field lines of the rotor and the magnetic field lines of the stator is a fixed angle, which is between 40 and 50 degrees. The controller includes: The grade determination module is used to determine the current change curve characterizing the current fluctuation of the target motor and the pressure change curve characterizing the aortic pressure fluctuation of the target object. The current change curve and the pressure change curve are input into a pre-trained grade prediction model to obtain the grade output by the grade prediction model, which serves as the target grade characterizing the degree of right ventricular recovery of the target object. The target object is the object to which the ventricular assist device is implanted. The grade prediction model is obtained by training an initial neural network using sample current change curves and sample pressure change curves as training samples and the actual grade characterizing the degree of right ventricular recovery of the sample object as the training benchmark. A current determination module is used to acquire the current current of the target motor and, based on the target level, determine the motor current suitable for the current right ventricular recovery level of the target object as the expected current. Specifically, the current determination module is used to: determine the rotational speed corresponding to the target level based on a preset correspondence between level and rotational speed, as the expected rotational speed; acquire the current rotational speed of the target motor and calculate the target rotational speed difference between the expected rotational speed and the current rotational speed; map the target rotational speed difference according to a preset mapping relationship between the rotational speed difference and the current to obtain a current suitable for the current right ventricular recovery level of the target object, as the expected current. A current mapping module is used to determine a first mapping component and a second mapping component of the current current of the target motor. The first mapping component is the current component mapped to the first coordinate axis in a preset coordinate system, and the second mapping component is the current component mapped to the second coordinate axis in the preset coordinate system. The preset coordinate system is a coordinate system constructed with the rotor center as the origin, the direction of the rotor magnetic field as the first coordinate axis, and the direction perpendicular to the rotor magnetic field as the second coordinate axis. A current fusion module is used to fuse the first mapping component and the second mapping component to obtain the target current; The voltage determination module is used to calculate the target current difference between the desired current and the target current, determine the voltage corresponding to the target current difference according to a preset mapping relationship between current difference and voltage, and determine the control voltage of the target motor based on the determined voltage. The motor control module is used to acquire the current magnetic field direction of the rotor, determine the target direction of the stator's clockwise magnetic field rotation along the current magnetic field direction, determine the coil conduction sequence of the stator corresponding to the target magnetic field rotation direction, and conduct the stator coils according to the coil conduction sequence and control voltage to control the target motor.

2. The system according to claim 1, characterized in that, The motor control module is specifically used to iteratively obtain the current magnetic field direction of the rotor as a reference direction, determine the clockwise direction along the reference direction and the preset sub-magnetic field direction that is closest to the reference direction, and determine the preset sub-magnetic field direction determined in each iteration as the target direction of magnetic field rotation; determine the conduction sequence of the stator coils corresponding to the target direction of magnetic field rotation according to the preset relationship between the magnetic field rotation direction and the coil conduction sequence; and conduct the stator coils according to the conduction sequence and the control voltage to control the target motor.

3. The system according to claim 1, characterized in that, The controller also includes an angle prediction module; The angle prediction module is used to predict the parameter value of the angle between the rotor magnetic field lines and the stator magnetic field lines based on the first mapping component and the second mapping component before the current fusion module, and use it as the predicted angle; if the predicted angle is consistent with the fixed angle, the current fusion module is triggered.

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