Control device, method and ventricular assist system for a ventricular assist device

Abstract

The application provides a control device, method and ventricular assist system of a ventricular assist device, and relates to the field of medical instrument control. The ventricular assist device comprises a pump and a motor, and the control device comprises a rotating speed correction module, a rotating speed estimation module and a motor control module; the rotating speed correction module is used for correcting a current rotating speed corresponding to a current flow of the pump based on a current pressure difference between a human ventricle and an artery to obtain a target rotating speed; the rotating speed estimation module is used for inputting a preset motor control amount into a rotating speed estimation model to obtain an estimated rotating speed; and the motor control module is used for adjusting the control amount of the motor according to the target rotating speed and the estimated rotating speed. The control device of the ventricular assist device is used to control the ventricular assist device, the change of the pressure difference caused by the contraction and diastole of the heart is considered, the control amount of the motor is adjusted based on the change of the pressure difference of the heart, and therefore the motor of the ventricular assist device can be controlled more accurately.

Description

Technical Field

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

[0002] A ventricular assist device (VAD) is an artificial blood pump connected in parallel with the heart. It simulates the function of the ventricles pumping blood into the arterial system, thus partially or completely replacing the heart's function. Therefore, it is often referred to as an "artificial heart".

[0003] In simulating ventricular ejection, it is necessary to control the flow rate of the ventricular assist device's pump; controlling the pump requires controlling the motor speed of the ventricular assist device. Currently, the ventricular assist device pump is controlled using PID (Proportional-Integral-Derivative) control, which controls the motor speed to reach a given target speed so that the blood flow reaches the expected level.

[0004] However, the environment inside the heart is complex, and the heart's contraction and relaxation may affect the blood flow of the pump itself. Therefore, using PID control may not necessarily keep the motor speed at the desired target speed. Summary of the Invention

[0005] The purpose of this application is to provide a control device, method, and ventricular assist system for a ventricular assist device. The control device of the ventricular assist device takes into account the pressure difference changes between the ventricle and artery caused by the contraction and relaxation of the heart, and adjusts the motor control quantity based on the changing pressure difference, thereby enabling more precise control of the motor of the ventricular assist device.

[0006] In a first aspect, embodiments of this application provide a control device for a ventricular assist device, the ventricular assist device including a pump and a motor; the control device includes: a speed correction module, a speed estimation module, and a motor control module; the speed correction module is used to correct the current speed corresponding to the current flow rate of the pump based on the current pressure difference between the human ventricle and the artery, to obtain a target speed; the speed estimation module is used to input a preset motor control quantity into a speed estimation model to obtain an estimated speed; wherein, the speed estimation model is a model reflecting the relationship between the current speed, the current flow rate, the preset motor control quantity, and the estimated speed; the motor control module is used to adjust the control quantity of the motor according to the target speed and the estimated speed.

[0007] In the above implementation process, when estimating the rotational speed, a rotational speed estimation model is used that reflects the relationship between the current rotational speed, current flow rate, preset motor control quantity, and estimated rotational speed. The preset motor control quantity is input into the rotational speed estimation model to obtain the estimated rotational speed. It should be noted that the preset motor control quantity can be a pre-set motor control quantity. After obtaining the estimated rotational speed, the motor control quantity is adjusted based on the target rotational speed and the estimated rotational speed. The control device for the ventricular assist device provided in this application embodiment considers the pressure difference changes caused by cardiac contraction and relaxation, and adjusts the control quantity of the motor based on the cardiac pressure difference changes, thereby enabling more precise control of the motor of the ventricular assist device.

[0008] Optionally, in this embodiment of the application, the speed correction module, in the process of correcting the current speed corresponding to the current flow rate of the pump based on the current pressure difference between the human ventricle and the artery to obtain the target speed, is specifically used to: construct the coupling relationship between the human body and the pump based on the current pressure difference, the current flow rate, and the current speed, and the coefficients of the current pressure difference, the current flow rate, and the current speed determined based on the current flow rate and the current pressure difference; and obtain the target speed based on the coupling relationship between the human body and the pump.

[0009] In the above implementation process, the coupling relationship between the human body and the pump fully describes the relationship between the contraction or relaxation of the human heart and the flow rate of the pump. Taking the coupling relationship between the human body and the pump into account in the control of the ventricular assist device, the control quantity of the ventricular assist device is adapted to the contraction and relaxation of the heart, which can improve the accuracy of the control of the ventricular assist device.

[0010] Optionally, in this embodiment, the method for constructing the speed estimation model includes: determining the motor load torque based on the current speed and current flow rate, and the coefficients of the motor's current speed and the pump's current flow rate determined based on the current current and current flow rate; and according to the formula... Determine the motor torque; where I is the preset motor control quantity, and K... b T is the back electromotive force constant of the motor. e The torque is the motor torque; based on the load torque and the motor torque, according to the motor dynamics formula: Determine the rotational speed estimation model; where J is the moment of inertia of the motor, w is the current angular velocity of the motor, B is the damping coefficient, and T... p This represents the load torque.

[0011] In the above implementation process, the speed estimation model can be expressed through the relationship between the current motor speed, the current pump flow rate, and the current motor current. The speed estimation model can accurately describe the relationship between motor speed and pump flow rate, and can be used to predict the motor speed at future times based on the current state of the motor and pump, which is beneficial to the accuracy of ventricular assist device control.

[0012] Optionally, in this embodiment, the motor control module includes a control function construction unit, a control quantity generation unit, and a control unit. During the process of adjusting the motor control quantity based on the target speed and the estimated speed: the control function construction unit generates the speed difference between the estimated speed and the predicted speed, and the control quantity difference between the current motor control quantity and the preset motor control quantity; and constructs a control function based on the speed difference and the control quantity difference; wherein the estimated speed is generated based on the target speed; the control quantity generation unit determines the preset motor control quantity corresponding to the minimum value of the control function, and uses the preset motor control quantity as the target motor control quantity; the control unit adjusts the motor control quantity from the current motor control quantity to the target motor control quantity.

[0013] In the above implementation process, the control device of the ventricular assist device provided in this application can determine the preset motor control quantity that meets the conditions (when the control function takes the minimum value) based on the estimated speed, the estimated speed, and the current motor control quantity. The control of the ventricular assist device takes into account the changes in intracardiac pressure caused by the contraction and relaxation of the human heart. It is no longer the case in the comparative embodiment that does not consider the special state of the heart and only controls the ventricular assist device with the target control quantity. The embodiment of this application constructs a control function, which not only realizes the adjustment of the control quantity according to the changes in cardiac pressure, but also improves the accuracy and stability of the control.

[0014] Optionally, in the embodiments of this application, the control function construction unit is specifically used to: determine the accuracy control parameter of the speed difference and the stability control parameter of the control quantity difference according to whether the human heart is in the systolic or diastolic phase at the current moment.

[0015] Optionally, in this embodiment of the application, the control function construction unit, in determining the accuracy control parameter of the speed difference and the stability control parameter of the control quantity difference based on whether the human heart is currently in systole or diastole, specifically performs the following: when the human heart is in systole, the stability control parameter is greater than the accuracy control parameter; when the human heart is in diastole, the accuracy control parameter is greater than the stability control parameter.

[0016] In the above implementation process, the control device of the ventricular assist device provided in this application, in order to maintain the accuracy and stability of the control, sets stability control parameters and accuracy control parameters based on the coupling relationship between the human body and the pump and the contraction or relaxation state of the heart. When using the control device of the ventricular assist device provided in the embodiments of this application, not only can the accurate control of the pump flow be achieved to adapt it to the activity of the heart, but also the stable control of the pump flow can be achieved, which is beneficial to improving the life of the hardware device.

[0017] Optionally, in this embodiment, the control function constructed by the control function construction unit includes: in, For the control function, w set (i+1) represents the estimated rotational speed. To estimate the rotational speed, u(i) is the target motor control input, u(i-1) is the current motor control input, k1 is the accuracy control parameter, k2 is the stability control parameter, and n is the prediction step number.

[0018] In the above implementation process, the control device of the ventricular assist device provided in this application can calculate the target motor control quantity to be given at the target time by using the current speed w of the motor, the current flow rate F of the pump, and the current motor control output u(i-1), so that the estimated speed at the target time is... The motor's estimated speed w is as close as possible to the target time. set (i+1), thereby achieving accurate and stable control of the ventricular assist device.

[0019] Secondly, embodiments of this application provide a ventricular assist system, which includes: a ventricular assist device having a pump and a motor, and a control device for the ventricular assist device according to any one of the first aspects of this application; the control device for the ventricular assist device is used to correct the current rotational speed corresponding to the current flow rate of the pump based on the current pressure difference between the human ventricle and the artery to obtain a target rotational speed; the control device for the ventricular assist device is also used to input a preset motor control quantity into a rotational speed estimation model to obtain an estimated rotational speed; and to adjust the motor control quantity according to the target rotational speed and the estimated rotational speed.

[0020] Thirdly, embodiments of this application provide a control method for a ventricular assist device. The control method includes: correcting the current speed corresponding to the current flow rate of the pump based on the current pressure difference between the human ventricle and the artery to obtain a target speed; inputting a preset motor control quantity into a speed estimation model to obtain an estimated speed; and adjusting the motor control quantity according to the target speed and the estimated speed.

[0021] Fourthly, embodiments of this application provide an electronic device, which includes a memory and a processor. The memory stores program instructions, and when the processor reads and runs the program instructions, it executes the steps in the implementation of the third aspect described above.

[0022] Fifthly, embodiments of this application also provide a computer-readable storage medium storing computer program instructions, which are read and executed by a processor to perform the steps in the implementation of the third aspect described above.

[0023] In a sixth aspect, embodiments of this application also provide a computer-readable medium storing instructions that, when executed by one or more processors, are adapted to cause one or more processors to perform a control method for a ventricular assist device. The method includes: correcting the current rotational speed corresponding to the current flow rate of a pump based on the current pressure difference between the ventricle and the artery to obtain a target rotational speed; inputting a preset motor control quantity into a rotational speed estimation model to obtain an estimated rotational speed; and adjusting the motor control quantity according to the target rotational speed and the estimated rotational speed. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of blood circulation provided for an embodiment of this application;

[0026] Figure 2 A flowchart illustrating the construction of a speed estimation model for the speed correction module provided in this application embodiment;

[0027] Figure 3 A control flowchart of the ventricular assist device provided in the embodiments of this application;

[0028] Figure 4 This is a schematic diagram of the ventricular assist system provided in an embodiment of this application;

[0029] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. For example, the flowcharts and block diagrams in the drawings illustrate the architecture, functions, and operations of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, program segment, or part of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions. In addition, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0031] Artificial hearts can be classified into left ventricular assist devices (LVADs), right ventricular assist devices (RVADs), biventricular assist devices (BiVADs), and total artificial hearts (TAHs). The left ventricle is the heart's main pumping ventricle, and most heart failures begin with left ventricular failure; therefore, LVADs are currently the most widely used in clinical practice. LVADs completely replace the left ventricular system as the heart's "pump" by introducing blood flow from the left atrium and left ventricle into an auxiliary pump, which then pumps the blood into the aorta. This makes them an ideal treatment for refractory heart failure or a temporary replacement for the heart while awaiting transplantation. During the simulation of ventricular ejection, the pump flow rate of the LVAD needs to be controlled; therefore, the prediction and calculation of the motor control parameters of the LVAD is an important research direction.

[0032] In the comparative embodiment, PID control is used to control the motor speed of the ventricular assist device, maintaining the motor speed at the desired speed, thereby controlling the blood flow of the pump. PID control is one of the most common control methods in control systems. For an automatic control system, if a steady-state error exists after reaching steady state, the control system is said to have a steady-state error, or simply a system with error. PID control calculates the control quantity based on the system error using proportional, integral, and derivative terms.

[0033] The inventors discovered that when using PID control to control motor speed, the complex intracardiac environment causes the heart to contract and relax, resulting in varying pressures within the heart at different times. Due to these pressure variations, it is difficult to maintain the motor speed at the desired level using PID control.

[0034] Based on this, this application provides a control device, method, and ventricular assist system for a ventricular assist device; the control device of the ventricular assist device takes into account the pressure difference changes between the ventricle and artery caused by the contraction and relaxation of the heart, and adjusts the motor control quantity based on the changing pressure difference, thereby enabling more precise control of the motor of the ventricular assist device.

[0035] This application provides a control device for a ventricular assist device, which includes a speed correction module, a speed estimation module, and a motor control module.

[0036] The control unit of a ventricular assist device includes a pump and a motor. The motor drives the pump to pump blood from the ventricle into the artery. The blood flow rate of the pump can be controlled by controlling the speed of the motor.

[0037] The speed correction module is used to correct the current speed of the pump corresponding to the current flow rate based on the current pressure difference between the human ventricle and artery, so as to obtain the target speed.

[0038] The pressure between the ventricles and arteries changes during the heart's contraction and relaxation processes; please refer to [link / reference needed] for details. Figure 1 , Figure 1 This is a schematic diagram of blood circulation provided in an embodiment of this application. Taking a left ventricular assist device (LVAD) as an example, the LVAD is located between the left ventricle and the aorta. During diastole, intracardiac pressure decreases, and venous blood flows back into the heart. During systole, intracardiac pressure increases, and the heart pumps blood from the heart into the arteries. The heart completes one heartbeat from the start of the next through systole and diastole. During these processes, intracardiac pressure changes with the cardiac cycle and is not constant. Therefore, incorporating changes in intracardiac pressure into the control of the LVAD improves the accuracy of its control. The speed correction module in this embodiment is designed to take into account changes in cardiac pressure differential, correcting the motor control based on real-time pressure differential changes, thereby reducing inaccurate motor control of the LVAD caused by pressure differential changes.

[0039] The speed estimation module is used to input preset motor control values ​​into the speed estimation model to obtain the estimated speed. The speed estimation model reflects the relationship between the current speed, current flow rate, preset motor control values, and the estimated speed.

[0040] The motor control module is used to adjust the control input of the motor based on the target speed and the estimated speed.

[0041] In the above implementation process, when estimating the rotational speed, a rotational speed estimation model is used that reflects the relationship between the current rotational speed, current flow rate, preset motor control quantity, and estimated rotational speed. The preset motor control quantity is input into the rotational speed estimation model to obtain the estimated rotational speed. It should be noted that the preset motor control quantity can be a pre-set motor control quantity. After obtaining the estimated rotational speed, the motor control quantity is adjusted based on the target rotational speed and the estimated rotational speed. The control device for the ventricular assist device provided in this application embodiment considers the pressure difference changes caused by cardiac contraction and relaxation, and adjusts the control quantity of the motor based on the cardiac pressure difference changes, thereby enabling more precise control of the motor of the ventricular assist device.

[0042] In an optional embodiment, the speed correction module, in the process of correcting the current speed corresponding to the current flow rate of the pump based on the current pressure difference between the human ventricle and artery to obtain the target speed, is specifically used for:

[0043] Based on the current differential pressure, current flow rate, and current rotational speed, and the coefficients for the current differential pressure, current flow rate, and current rotational speed determined based on the current flow rate and current differential pressure, a coupling relationship between the human body and the pump is constructed. Furthermore, based on this coupling relationship, the target rotational speed is obtained.

[0044] Based on the current pressure difference between the ventricles and arteries, the current speed of the motor, the current flow rate of the pump, and the hydraulic characteristic formula of fluid dynamics, the current flow velocity of the pump can be obtained:

[0045]

[0046] In Equation 1), F is the current flow rate, w is the current rotational speed, and ΔP is the pressure difference across the pump. For the current flow coefficient, For the current speed coefficient, b0, b1, and b2 are the current differential pressure coefficients; b0, b1, and b2 are the system constant coefficients. Multiple sets of pump flow rate, motor speed, and pump differential pressure data can be obtained through external testing to obtain the HQ curve (the curve represents the relationship between the pump flow rate and the head H), which is then fitted to the curve.

[0047] Since the catheter pump, as a ventricular assist device, needs to be placed between the ventricle and the artery, the pressure difference across the pump, ΔP, in equation 1) can be expressed as: ΔP = P A -P L Among them, P A For arterial pressure, P LThis represents ventricular pressure; that is, ΔP is the current pressure difference between the ventricles and arteries in the human body. It fully reflects the coupling relationship between the human body and the pump of the ventricular assist device. Therefore, the coupling relationship between the human body and the pump can be expressed as:

[0048]

[0049] The coupling relationship between the human body and the pump fully describes the relationship between the contraction or relaxation of the human heart and the flow rate of the pump. Taking the coupling relationship between the human body and the pump into account in the control of the ventricular assist device, so that the control amount of the ventricular assist device is adapted to the contraction and relaxation of the heart, can improve the accuracy of the control of the ventricular assist device.

[0050] Please refer to Figure 2 , Figure 2 A flowchart illustrating the construction of a speed estimation model for the speed correction module provided in this application embodiment; in an optional embodiment, the construction of the speed estimation model includes the following steps:

[0051] Step S110: Determine the load torque of the motor based on the current speed and current flow rate, as well as the coefficients of the motor's current speed and the pump's current flow rate determined based on the current current and current flow rate.

[0052] In step S110 above, the load torque of the motor is related to the pump and satisfies the following formula:

[0053] T p =a1w 2 +a2F 2 In equation 3), T p Here, F is the load torque, w is the current flow rate of the pump, and a1 and a2 are constant coefficients, where a1 is the coefficient for the current speed and a2 is the coefficient for the current flow rate. a1 and a2 can be obtained by fitting multiple sets of relationships between motor speed and pump flow rate obtained through external testing.

[0054] It should be noted that the expression of load torque is not limited to Equation 3) above, and there may be multiple forms of expression, such as load torque T. p It can be a combination of polynomials of rotational speed w and flow rate F, which can reflect the coupling between the motor and the pump. Equation 3) above is only one possible implementation.

[0055] Step S120: According to the formula Determine the motor torque.

[0056] In step S120 above, according to the formula Determine the motor torque; I is the preset motor control quantity, K b T is the back electromotive force constant of the motor. eThis represents the motor torque.

[0057] Step S130: Based on the load torque and motor torque, according to the motor dynamics formula: Determine the rotational speed estimation model.

[0058] In step S130 above, based on the load torque, according to the motor dynamics formula: Determine the coupling relationship between the motor and the pump; where J is the moment of inertia of the motor, w is the current angular velocity of the motor, B is the damping coefficient, and T... p T represents the load torque. e This represents the motor torque.

[0059] Taking the load torque expressed in equation 3) above as an example, based on the motor dynamics formula: The motor rotation speed can be obtained:

[0060]

[0061] Therefore, the coupling relationship between the motor and the pump can be expressed as:

[0062]

[0063] Therefore, the speed estimation model can be expressed through the relationship between the current motor speed, the current pump flow rate, and the current motor current. This speed estimation model accurately describes the relationship between motor speed and pump flow rate, and can be used to predict the motor speed at future times based on the current state of the motor and pump, which is beneficial for the accuracy of ventricular assist device control.

[0064] In an optional embodiment, the motor control module includes a control function construction unit, a control quantity generation unit, and a control unit. During the process of adjusting the motor's control quantity based on the target speed and the estimated speed:

[0065] The control function construction unit is used to generate the speed difference between the predicted speed and the estimated speed, as well as the control difference between the current motor control quantity and the preset motor control quantity; and to construct a control function based on the speed difference and the control difference. The predicted speed is generated based on the target speed.

[0066] The estimated rotational speed can be obtained using equation 1) above. Taking the control of the target flow rate as an example, unaffected by the cardiac systolic and diastolic phases, let equation 1)... The target rotational speed can be derived as follows:

[0067]

[0068] In equation 5), F setLet ΔP be the target flow rate, and ΔP be the pressure difference between the ventricle and aorta at the current moment. It should be noted that in practical applications, the target flow rate can be stable or variable, depending on the actual control strategy. Further, by transforming Equation 5), the estimated rotational speed is obtained:

[0069]

[0070] In equation 6), F set (i+1) can be understood as the flow rate at the target time, and ΔP(i+1) can be understood as the pressure difference between the ventricle and aorta at the target time; F set (i+1) and ΔP(i+1) can be calculated using the methods provided above, and will not be repeated here.

[0071] The control quantity generation unit is used to determine the preset motor control quantity corresponding to the minimum value of the control function, and use the preset motor control quantity as the target motor control quantity.

[0072] Furthermore, the control unit is used to adjust the motor control quantity from the current motor control quantity to the target motor control quantity.

[0073] In the above implementation process, the control function construction unit constructs a control function for the difference between the estimated speed and the predicted speed, and the difference between the current motor control quantity and the preset motor control quantity. The preset motor control quantity when the control function reaches its minimum value is used as the target motor control quantity to control the motor speed.

[0074] The control device for the ventricular assist device provided in this application can determine a preset motor control quantity that meets the conditions (when the control function takes the minimum value) based on the estimated speed, the estimated speed, and the current motor control quantity. The control of the ventricular assist device takes into account the changes in intracardiac pressure caused by the contraction and relaxation of the human heart. It is no longer the case in the comparative embodiment that does not consider the special state of the heart and simply controls the ventricular assist device with the target control quantity. The embodiment of this application constructs a control function, which not only realizes the adjustment of the control quantity according to the changes in cardiac pressure, but also improves the accuracy and stability of the control.

[0075] In an optional embodiment, the control function construction unit is specifically used to construct the control function based on the speed difference and the control quantity difference in the process of constructing the control function:

[0076] Based on whether the human heart is currently in systole or diastole, determine the accuracy control parameters for the speed difference, and determine the stability control parameters for the control quantity difference.

[0077] Control parameters related to the control of ventricular assist devices (VADs) include accuracy control parameters and stability control parameters. Due to the special function of VADs, the pump flow rate may vary at any given time, and there may be an error between the actual control quantity and the predicted control quantity at any given time. This error reflects the accuracy of the control; therefore, it is necessary to determine parameters related to control accuracy. On the other hand, for any control method, stable control of the VAD is required. Unstable control can easily damage the hardware and reduce the lifespan of the device. For VADs placed inside the patient's body, device placement and replacement are extremely complex; therefore, the lifespan of the device is extremely important, necessitating a highly stable control scheme.

[0078] In the above implementation process, the control quantity difference is the difference between the preset motor control quantity (i.e., the desired target motor control quantity) and the current motor control quantity. For a ventricular assist device, the current motor control quantity can be controlled in various ways to regulate the pump flow rate, such as maintaining a constant flow rate or controlling the flow rate to vary with cardiac activity. The predicted motor control quantity, i.e., the desired target motor control quantity, is influenced by the actual condition of the pump and the current state of the motor, which can affect the control quantity of the ventricular assist device at the next moment. Therefore, the predicted motor control quantity can be understood as the target control quantity predicted based on the current condition of the motor and the current state of the pump.

[0079] Based on the above introduction, the control quantity difference is used to represent the change between the control quantity of the motor at the current moment and the control quantity of the target motor. The change of this control quantity difference can affect the stability of the entire control. For example, if the change of the control quantity between the current moment and the subsequent moment is too large, it may be unstable. Therefore, the stability control parameter needs to control the stability of this change as much as possible.

[0080] In an optional embodiment, the control function construction unit is specifically used to determine the accuracy control parameters for the speed difference and the stability control parameters for the control quantity difference based on whether the human heart is currently in systole or diastole.

[0081] When the human heart is in the contraction phase, the stability control parameter is greater than the accuracy control parameter.

[0082] When the human heart is in diastole, the accuracy control parameter is greater than the stability control parameter.

[0083] Because the heart's pumping flow control requirements differ between systole and diastole, during diastole, intracardiac pressure decreases, requiring the pump to provide auxiliary flow to allow venous blood to return to the heart; therefore, accurate control is more important during diastole. During systole, intracardiac pressure increases, and the heart itself pumps blood from the heart into the arteries; therefore, stable control is more important during systole.

[0084] For example, if k1 is the accuracy control parameter and k2 is the stability control parameter, then the values ​​of the accuracy control parameter and the stability control parameter are as follows:

[0085]

[0086] Where δ∈[0,0.5]; when the heart is in diastole, the control of the ventricular assist device focuses on accuracy, k1>k2; when the heart is in systole, the control of the ventricular assist device focuses on stability, k1 <k2。

[0087] Therefore, it can be seen that, in order to maintain the accuracy and stability of control, the control device of the ventricular assist device provided in this application sets stability control parameters and accuracy control parameters based on the coupling relationship between the human body and the pump and the contraction or relaxation state of the heart. When using the control device of the ventricular assist device provided in the embodiments of this application, not only can the pump flow be accurately controlled to adapt to the activity of the heart, but also the pump flow can be stably controlled, which is beneficial to improving the life of the hardware device.

[0088] In an optional embodiment, the control function constructed by the motor control function construction module include:

[0089]

[0090] In equation 7), w set (i+1) represents the estimated speed of the motor. k1 is the accuracy control parameter, which is the estimated speed predicted based on the current state of the motor. This can reflect the accuracy of motor control. The goal is to adjust the control input so that the estimated speed is close to the predicted speed.

[0091] In Equation 7), u(i) is the preset motor control quantity, u(i-1) is the current motor control quantity, and k2 is the stability control parameter; k2(u(i)-u(i-1)) 2 This demonstrates the stability of motor control. The preset motor control quantity u(i) and the current motor control quantity u(i-1) can both be considered as the motor current.

[0092] In Equation 7), n is the number of prediction steps. Usually, n is 1, which means predicting the motor control quantity for the next step at the current moment.

[0093] Estimated speed at future moments based on the current state of the motor Equation 4) can be discretized using the above equation:

[0094]

[0095] Transforming step 8) yields the estimated rotational speed at subsequent time points:

[0096]

[0097] In Equations 8) and 9), ΔT is the sampling interval time, which is determined according to the hardware conditions of the ventricular assist device.

[0098] Furthermore, taking a control step of 1 step as an example, the w(t+1) calculated by equation 9) is substituted into the estimated rotational speed in equation 7). In the middle, the estimated rotational speed is calculated using equation 6). Substituting u(i) into equation 7), we get the following equation instead of I(t):

[0099]

[0100] In the process of calculating the target motor control quantity, the control quantity generation unit is specifically used to: find the minimum value of the control function and determine the target motor control quantity corresponding to the minimum value.

[0101] As can be seen from Equation 10), the control function For the quadratic term of the target motor control quantity u(i), it can be obtained through... Differentiating u yields

[0102] To simplify the calculation process, let:

[0103]

[0104]

[0105] α1=k1q1 2 +k2 (Equation 13)

[0106] α2=2k1q1(w set (i+1)+m1)-2u(i-1) Equation 14)

[0107] α3=k1((w set (i+1)+m1) 2 +k2u2 Substituting equations 11 and 15 into equation 10 above, we get:

[0108]

[0109] Furthermore, the control function Differentiating u, we get: when hour, Minimum value can be obtained:

[0110]

[0111] Substituting equations 11)-15) into equation 16) to restore equation 16), we can obtain the target motor control quantity:

[0112]

[0113] Among them, F set (i+1) represents the target flow rate (which can be stable or variable). The target flow rate varies depending on the ventricular assist device's setting. ΔP(i+1) represents the target pressure difference, which is related to the heart's contraction and relaxation.

[0114] In other words, the control device of the ventricular assist device provided in this application can calculate the target motor control quantity to be given at the target time based on the current motor speed w, the current pump flow rate F, and the current motor control output u(i-1), so that the estimated speed at the target time is... The motor's estimated speed w is as close as possible to the target time. set (i+1), thereby achieving accurate and stable control of the ventricular assist device.

[0115] Please refer to Figure 3 , Figure 3 This application provides a control flowchart for a ventricular assist device according to an embodiment of the present application. The present application also provides a control method for a ventricular assist device, which is applied to the control device of the ventricular assist device provided in this application. The control method includes the following steps:

[0116] Step S100: Based on the current pressure difference between the human ventricle and artery, correct the current speed corresponding to the current flow rate of the pump to obtain the target speed.

[0117] Step S200: Input the preset motor control quantity into the speed estimation model to obtain the estimated speed.

[0118] Step S300: Adjust the motor control quantity based on the target speed and the estimated speed.

[0119] For details on obtaining the target rotational speed and constructing the rotational speed estimation model in steps S100 to S300 above, please refer to the description of the control device of the ventricular assist device in this application, which will not be repeated here.

[0120] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the structure of the ventricular assist system provided in the embodiments of this application; this application also provides a ventricular assist system 200, which includes a control device 100 for the ventricular assist device and a ventricular assist device (VAD) of this application, and uses the control device for the ventricular assist device (VAD) to realize the control of the ventricular assist device (VAD).

[0121] The control device 100 of the ventricular assist device is used to correct the current speed corresponding to the current flow rate of the pump based on the current pressure difference between the human ventricle and the artery, so as to obtain the target speed.

[0122] The control device 100 of the ventricular assist device is also used to input a preset motor control quantity into the speed estimation model to obtain an estimated speed; and to adjust the motor control quantity according to the target speed and the estimated speed.

[0123] exist Figure 4 In the middle, the ventricular assist device control device 100 collects the target flow rate F. set And the pressure difference ΔP between the ventricle and aorta at the current moment, through The target speed is obtained, which is then used to correct the current speed corresponding to the current flow rate of the pump.

[0124] Furthermore, the ventricular assist device control device 100 is based on the target rotational speed w set The estimated rotational speed is calculated as follows:

[0125] The ventricular assist device control unit 100 estimates the rotational speed based on the current motor speed, current current, and current pump flow rate, according to the formula... The estimated rotational speed was calculated.

[0126] The ventricular assist device control unit 100 will estimate the rotational speed w(t+1) and predict the rotational speed w set Substitute (i+1) into the constructed control function In the middle, and obtain the control function. The minimum value of the control quantity is used to obtain the target control quantity (in the form of current), and the ventricular assist device (VAD) is controlled by the target control quantity.

[0127] For details on the operation of the control device 100 for the ventricular assist device, please refer to the description of the control device for the ventricular assist device in this application; it will not be repeated here.

[0128] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. An electronic device 300 provided in this application includes: a processor 301 and a memory 302. The memory 302 stores machine-readable instructions executable by the processor 301. When the machine-readable instructions are executed by the processor 301, the method described above is performed.

[0129] Based on the same inventive concept, embodiments of this application also provide a computer-readable storage medium storing computer program instructions. When the computer program instructions are read and executed by a processor, they perform the steps in the implementation of the control method for the ventricular assist device described above.

[0130] The computer-readable storage medium can be any medium capable of storing program code, such as Random Access Memory (RAM), Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM).

[0131] Based on the same inventive concept, embodiments of this application also provide a computer-readable medium storing instructions, which, when executed by one or more processors, are adapted to cause one or more processors to perform a control method for a ventricular assist device, the method comprising:

[0132] Based on the current pressure difference between the ventricle and artery in the human body, the current speed corresponding to the current flow rate of the pump is corrected to obtain the target speed; the preset motor control quantity is input into the speed estimation model to obtain the estimated speed; the control quantity of the motor is adjusted according to the target speed and the estimated speed.

[0133] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying 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 limitation, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0134] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A control device for a ventricular assist device, characterized in that, The ventricular assist device includes a pump and a motor; the control device includes: a speed correction module, a speed estimation module, and a motor control module; The speed correction module is used to correct the current speed corresponding to the current flow rate of the pump based on the current pressure difference between the human ventricle and artery, so as to obtain the target speed. The speed estimation module is used to input a preset motor control quantity into the speed estimation model to obtain the estimated speed; wherein, the speed estimation model is a model that reflects the relationship between the current speed, the current flow rate, the preset motor control quantity, and the estimated speed; The motor control module is used to adjust the control quantity of the motor according to the target speed and the estimated speed; The motor control module includes a control function construction unit, a control quantity generation unit, and a control unit; in the process of adjusting the control quantity of the motor according to the target speed and the estimated speed: The control function construction unit is used to generate the speed difference between the estimated speed and the predicted speed, and the control difference between the current motor control quantity and the preset motor control quantity; and A control function is constructed based on the speed difference and the control quantity difference; wherein the estimated speed is generated based on the target speed. The control quantity generation unit is used to determine the preset motor control quantity corresponding to the minimum value of the control function based on the minimum value of the control function, and use the preset motor control quantity as the target motor control quantity. The control unit is used to adjust the control quantity of the motor from the current motor control quantity to the target motor control quantity; Specifically, the control function construction unit is used in the process of constructing the control function based on the speed difference and the control quantity difference to: Based on whether the human heart is currently in systole or diastole, the accuracy control parameters for the speed difference and the stability control parameters for the control quantity difference are determined.

2. The apparatus according to claim 1, characterized in that, The speed correction module is specifically used in the process of correcting the current speed corresponding to the current flow rate of the pump based on the current pressure difference between the human ventricle and artery to obtain the target speed, and is specifically used for: Based on the current differential pressure, current flow rate, and current rotational speed, and the coefficients of the current differential pressure, current flow rate, and current rotational speed determined based on the current flow rate and the current differential pressure, a coupling relationship between the human body and the pump is constructed. The target rotational speed is obtained based on the coupling relationship between the human body and the pump.

3. The apparatus according to claim 1, characterized in that, in, The method for constructing the speed estimation model includes: The load torque of the motor is determined based on the current rotational speed and current flow rate, as well as the coefficients of the current rotational speed of the motor and the current flow rate of the pump, which are determined based on the current current and current flow rate. According to the formula Determine the motor torque of the motor; wherein, This refers to the preset motor control quantity. Let be the back electromotive force constant of the motor. This refers to the motor torque; Based on the load torque and the motor torque, according to the motor dynamics formula: Determine the rotational speed estimation model; wherein, Let be the moment of inertia of the motor. This represents the current angular velocity of the motor. The damping coefficient is... This represents the load torque.

4. The apparatus according to claim 1, characterized in that, The control function construction unit is specifically used in the process of determining the accuracy control parameters of the speed difference and the stability control parameters of the control quantity difference based on whether the human heart is currently in systole or diastole. When the human heart is in the systolic phase, the stability control parameter is controlled to be greater than the accuracy control parameter; When the human heart is in diastole, the accuracy control parameter is controlled to be greater than the stability control parameter.

5. The apparatus according to claim 1, characterized in that, The control functions constructed by the control function construction unit include: ;in, For control functions, For the estimated rotational speed, For the estimated rotational speed, The target motor control quantity. The current motor control quantity, To ensure accurate control parameters, Here, n is the stability control parameter, and n is the number of prediction steps.

6. A ventricular assist system, characterized in that, The ventricular assist system includes: a ventricular assist device having a pump and a motor, and a control device for the ventricular assist device as described in any one of claims 1-5; The control device of the ventricular assist device is used to correct the current speed corresponding to the current flow rate of the pump based on the current pressure difference between the human ventricle and the artery, so as to obtain the target speed. The control device of the ventricular assist device is also used to input a preset motor control quantity into a speed estimation model to obtain an estimated speed; and The control quantity of the motor is adjusted based on the target speed and the estimated speed.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions that, when executed by a processor, perform the following steps in the ventricular assist system as described in claim 6, wherein the ventricular assist system comprises: a ventricular assist device having a pump and a motor, and a control device for the ventricular assist device as described in any one of claims 1-5: Based on the current pressure difference between the human ventricle and artery, the current speed corresponding to the current flow rate of the pump is corrected to obtain the target speed; The preset motor control value is input into the speed estimation model to obtain the estimated speed; wherein, the speed estimation model is a model that reflects the relationship between the current speed, the current flow rate, the preset motor control value, and the estimated speed; The control quantity of the motor is adjusted based on the target speed and the estimated speed.

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