Control device and method and ventricular assist system

Abstract

The invention provides a control device and method and a ventricular assist system, and relates to the field of medical instrument control. The control device is used for controlling the ventricular assist device; the control period of the control device is a comprehensive control period; the control device comprises a comprehensive control strategy generation module and a motor control module. The comprehensive control strategy generation module is used for determining a low-dropout control strategy based on the original control strategy to obtain a comprehensive control strategy; wherein the original control strategy is used for maintaining cardiac output in a comprehensive control period; the low-pressure control strategy is used for reducing blood vessel pressure generated by the original control strategy; and the motor control module is used for controlling the rotating speed of a motor of the ventricular assist device according to a comprehensive control strategy in the comprehensive control period. By means of the control device, normal cardiac output can be guaranteed, and meanwhile reflux passing through the aortic valve is effectively reduced.

Description

Technical Field

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

[0002] A ventricular assist device (VAD) is an artificial blood pump that is connected in parallel with the heart to simulate the function of ventricular ejection. It pumps blood from the ventricles into the arterial system, partially or completely replacing the function of the heart. Therefore, it is often called an "artificial heart."

[0003] The left ventricular assist device (LVAD) is one of the ventricular assist devices. It completely replaces the function of the left heart system as a heart "pump" by directing blood flow from the left atrium and left ventricle into the assist pump, and then pumping the blood into the aorta. It is an ideal means of treating refractory heart failure, or it can serve as a temporary replacement heart while waiting for a heart transplant.

[0004] However, long-term left ventricular assist device support may lead to various complications, especially in patients using non-pulsatile, continuous blood flow left ventricular assist device pumps. Aortic insufficiency (AI) is a problem that needs to be improved urgently. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a control device, method and ventricular assist system, which generates a low pressure difference control strategy through a comprehensive control strategy generation module to form a comprehensive control strategy; the control device provided by the embodiments of the present application can effectively reduce aortic valve regurgitation while ensuring normal cardiac output.

[0006] In a first aspect, an embodiment of the present application provides a control device, which is used to control a ventricular assist device; the control cycle of the control device is a comprehensive control cycle; the control device includes: a comprehensive control strategy generation module and a motor control module; the comprehensive control strategy generation module is used to determine a low pressure difference control strategy based on an original control strategy to obtain a comprehensive control strategy; wherein the original control strategy is used to maintain cardiac output within the comprehensive control cycle; the low pressure control strategy is used to reduce the vascular pressure generated by the original control strategy; the motor control module is used to control the motor speed of the ventricular assist device with the comprehensive control strategy within the comprehensive control cycle.

[0007] In the above implementation process, the control device provided by the present application includes a comprehensive control strategy generation module and a motor control module; a low pressure difference control strategy is generated by the comprehensive control strategy generation module. Due to the setting of the low pressure difference control strategy, the vascular pressure difference caused by the original control strategy is reduced, thereby improving the aortic valve regurgitation problem.

[0008] Optionally, in an embodiment of the present application, the comprehensive control strategy generation module includes: a low-pressure control strategy generation sub-module; in the process of determining the low-pressure difference control strategy based on the original control strategy, the low-pressure control strategy generation sub-module is specifically used to: obtain the minimum value of the original target pressure difference corresponding to the original control strategy; and determine the objective function whose function average value is less than the minimum value of the original target pressure difference as the low-pressure control function of the low-pressure control strategy.

[0009] In the above implementation process, by setting the low pressure difference control strategy generation submodule, the minimum original target pressure difference corresponding to the original control strategy is obtained; further, the target function whose function mean is less than the minimum original target pressure difference is used as the low pressure difference control function, so as to meet the control requirements of the ventricular assist device while reducing the pressure difference mean within the comprehensive control cycle, thereby effectively reducing the problem of blood regurgitation through the aortic valve.

[0010] Optionally, in an embodiment of the present application, the comprehensive control strategy generation module also includes: a control proportion determination sub-module; in the process of determining the low pressure difference control strategy based on the original control strategy to obtain the comprehensive control strategy, the control proportion sub-module is specifically used to: determine the low pressure difference proportion duration of the low pressure control strategy within the comprehensive control cycle to obtain a comprehensive control strategy including the original control strategy and the low pressure difference control strategy; wherein, the low pressure difference proportion duration is positively correlated with the average value of the low pressure difference control function.

[0011] In the above implementation process, the embodiment of the present application determines the proportion of the original control strategy and the low pressure difference control strategy in the entire comprehensive control cycle through the control proportion determination submodule. Only under a reasonable control proportion can it be achieved to both meet the control requirements and reduce the regurgitation through the aortic valve.

[0012] Optionally, in an embodiment of the present application, the original control strategy includes a control strategy based on pulsation; in the process of determining the low pressure difference control strategy based on the original control strategy to obtain a comprehensive control strategy: the comprehensive control strategy generation module is used to connect the low pressure difference control strategy in series after the pulsation control function to obtain a comprehensive control strategy; wherein the pulsation control function is a control function of the control strategy based on pulsation.

[0013] In the above implementation process, when the original control strategy is a control strategy based on pulsation, a low-pressure difference control function is connected in series after the pulsation control function corresponding to the pulsation-based control strategy, so as to obtain a comprehensive control strategy; further, the control ratio relationship between the pulsation control function and the low-pressure difference control function is adjusted. When the control ratio parameter is relatively small, it means that the proportion of the low pressure difference is relatively large. At this time, the pulsation effect is relatively weak and cannot provide enough cardiac output; when the control ratio parameter is relatively large, the pulsation control ratio is relatively large, and the aortic reflux is more; therefore, by adjusting the control ratio parameter, the aortic reflux can be controlled.

[0014] Optionally, in an embodiment of the present application, in the process of controlling the motor speed of the ventricular assist device with a comprehensive control strategy within a comprehensive control cycle, the motor control module is specifically used to: within the comprehensive control cycle, control the motor speed with the original target pressure difference corresponding to the original control strategy within the original control proportion time, and control the motor speed with the target low pressure difference corresponding to the low pressure control strategy within the low pressure difference proportion time; wherein, the original control proportion time and the low pressure difference proportion time constitute a comprehensive control cycle; and the comprehensive control cycle is an integer multiple of the human cardiac cycle.

[0015] In the above implementation process, the motor control module subtracts the target pressure difference corresponding to the comprehensive control function composed of the original control strategy and the low pressure difference control strategy from the current pressure difference to obtain the pressure difference value; based on the pressure difference value, the control quantity for controlling the motor is generated, and the motor is controlled by the control quantity. Due to the existence of the low pressure difference control function, the average pressure difference within the cycle can be effectively reduced, thereby improving the aortic regurgitation problem.

[0016] Optionally, in an embodiment of the present application, the comprehensive control generation module is further used to receive a backflow signal before determining the low pressure difference control strategy based on the original control strategy to obtain the comprehensive control strategy.

[0017] In the above implementation process, the regurgitation through the aortic valve can be monitored by the regurgitation detection device or the regurgitation detection module. When the aortic regurgitation exceeds the threshold, the regurgitation detection device or the module can send a regurgitation signal. When the control device provided in the embodiment of the present application receives the regurgitation signal, the motor speed of the ventricular assist device can be controlled by a comprehensive control strategy, so that the aortic regurgitation can be reduced in time.

[0018] In a second aspect, an embodiment of the present application provides a ventricular assist system, which includes: a control device and a ventricular assist device as provided in the first aspect of the present application; the control device is used to determine a low pressure difference control strategy based on an original control strategy to obtain a comprehensive control strategy; the control device is also used to control the motor speed of the ventricular assist device according to the comprehensive control strategy.

[0019] In a third aspect, an embodiment of the present application provides a control method for controlling a control device of a ventricular assist device; the control device includes a comprehensive control strategy generation module and a motor control module; the method includes: the comprehensive control strategy generation module determines a low pressure difference control strategy based on an original control strategy to obtain a comprehensive control strategy; wherein the original control strategy is used to maintain cardiac output within a comprehensive control cycle; the low pressure control strategy is used to reduce the vascular pressure generated by the original control strategy; and the motor control module controls the motor speed of the ventricular assist device with the comprehensive control strategy within the comprehensive control cycle.

[0020] In a fourth aspect, an embodiment of the present application provides an electronic device, comprising a memory and a processor, wherein the memory stores program instructions, and when the processor reads and runs the program instructions, it executes the steps in any of the above implementation methods.

[0021] In a fifth aspect, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer program instructions are stored in the computer-readable storage medium, and when the computer program instructions are read and executed by a processor, the steps in any of the above-mentioned implementation methods are executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A first schematic diagram of a module of a control device provided in an embodiment of the present application;

[0024] Figure 2 A second schematic diagram of a module of a control device provided in an embodiment of the present application;

[0025] Figure 3 A schematic diagram of a comprehensive control function provided in an embodiment of the present application;

[0026] Figure 4 A flow chart of a control method provided in an embodiment of the present application;

[0027] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions and operations of the systems, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flowchart or block diagram may represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the box may also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they may sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of boxes in the block diagram and / or the flowchart, can be implemented by a dedicated hardware-based system that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions. In addition, the functional modules in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist separately, or two or more modules can be integrated to form an independent part.

[0029] Artificial hearts can be divided into left ventricular assist devices (LVAD), right ventricular assist devices (RVAD), biventricular assist devices (BiVAD) and total artificial hearts (TAH). The left ventricle is an important ventricle of the heart that pumps blood. Most heart failures start with left heart failure; therefore, the left ventricular assist device (LVAD) is currently the most widely used in clinical practice. The left ventricular assist device completely replaces the function of the left heart system as a heart "pump" by directing blood flow from the left atrium and left ventricle into the auxiliary pump, and then pumping the blood flow into the aorta. It is an ideal means of treating refractory heart failure, or it can serve as a temporary replacement heart while waiting for a heart transplant.

[0030] During the research process, the applicant found that left ventricular assist device implantation has played an increasingly important role in the treatment of end-stage heart failure (HF) in the past decade. However, long-term LVAD support can lead to various complications, especially in patients using non-pulsatile, continuous blood flow LVAD pumps, aortic insufficiency (AI) is one of them. The occurrence and progression of aortic regurgitation will reduce the output of the left ventricular assist device pump, which can lead to structural damage to the valve, repeated heart failure, and increased patient mortality.

[0031] Based on this, the present solution proposes a control device, method and ventricular assist system that can improve the problem of aortic valve regurgitation by connecting a low pressure difference control strategy in series on the basis of the original control strategy to reduce the aortic pressure caused by the original control strategy.

[0032] In medicine, aortic valve regurgitation generally refers to the blood backflow caused by incomplete closure due to valve dysfunction. For patients using ventricular assist devices, when the heart is in diastole, the valve is closed; however, due to the presence of the catheter pump, there is a gap between the valve and the valve, which causes backflow, resulting in structural damage to the human valve.

[0033] Please see Figure 1 , Figure 1 This is a first schematic diagram of a module of a control device provided in an embodiment of the present application; the control device provided in an embodiment of the present application is used to control a ventricular assist device, and the control device includes: a comprehensive control strategy generation module and a motor control module.

[0034] The comprehensive control strategy generation module is used to determine the low pressure difference control strategy based on the original control strategy to obtain the comprehensive control strategy.

[0035] In the above process, the control cycle corresponding to the comprehensive control strategy is the comprehensive control cycle. The original control strategy is used to maintain the cardiac output within the comprehensive control cycle, and the low-pressure control strategy is used to reduce the vascular pressure generated by the original control strategy.

[0036] An original control strategy and a low-pressure difference control strategy are set within the entire integrated control cycle; wherein the original control strategy may include a specific function that satisfies the cardiac output within the integrated control cycle, while the low-pressure difference control strategy is determined based on the original control strategy and is set to reduce the vascular pressure generated within the original control cycle.

[0037] It should be noted that, in some cases, in order to meet the total cardiac output required within the comprehensive control cycle, the average cardiac output within the original control cycle can be appropriately increased to compensate for the loss of cardiac output caused by setting the low pressure difference control strategy.

[0038] The motor control module is used to control the motor speed of the ventricular assist device with a comprehensive control strategy within a comprehensive control cycle.

[0039] Specifically, the motor control module controls the motor speed of the ventricular assist device according to the target pressure difference generated by the original control strategy during the original control period corresponding to the original control strategy; and controls the motor speed of the ventricular assist device according to the target pressure difference generated by the low pressure difference control strategy during the low pressure difference control cycle corresponding to the low pressure difference control strategy. It can be understood that the sum of an original control period and a low pressure difference control cycle in the above process should be equal to a comprehensive control cycle.

[0040] For the left ventricular assist device, since the mechanical pump of the left ventricular assist device is placed between the left ventricle and the aorta, the mechanical pump draws blood from the left ventricle and pushes it to the aorta, thereby providing sufficient blood supply to various organs of the body. During the operation of the left ventricular assist device, blood can be pumped at a constant rate or based on a specific function; if a large pressure is continuously maintained in the aorta, regurgitation through the aortic valve may occur when the aortic valve is closed.

[0041] pass Figure 1 It can be seen that the control device provided in the present application includes a comprehensive control strategy generation module and a motor control module; a low pressure difference control strategy is generated by the comprehensive control strategy generation module. Due to the setting of the low pressure difference control strategy, the vascular pressure difference generated by the original control strategy is reduced, thereby improving the problem of trans-aortic valve regurgitation.

[0042] Please see Figure 2 , Figure 2 A second schematic diagram of a module of a control device provided in an embodiment of the present application; in an optional implementation of an embodiment of the present application, the comprehensive control strategy generation module includes: a low-voltage control strategy generation sub-module.

[0043] In the process of determining the low pressure difference control strategy based on the original control strategy, the low pressure control strategy generation submodule is specifically used to: obtain the minimum value of the original target pressure difference corresponding to the original control strategy, and determine the objective function whose function average value is less than the minimum value of the original target pressure difference as the low pressure control function of the low pressure control strategy.

[0044] The minimum value of the original target pressure difference corresponding to the original control strategy is obtained, and the target function whose average value is less than the minimum value is determined, that is, the target function is the low pressure difference control function corresponding to the low pressure difference control strategy. For example, if the minimum value of the original target pressure difference corresponding to the original control strategy is 30 mmHg, then the average value of the low pressure difference control function only needs to be less than 30 mmHg; that is, any function whose average value is less than 30 mmHg can be determined as the low pressure difference control function in the embodiment of the present application.

[0045] The low pressure difference control function can be understood as a function that can control the pressure difference or the mean pressure difference within a comprehensive control cycle within an appropriate range; the appropriate range can be understood as being able to ensure the control requirements of the ventricular assist device (each gear has a corresponding cardiac output, and the control requirements of the ventricular assist device can be understood as being able to achieve basic gear control of the ventricular assist device); at the same time, under the control of the low pressure difference control function, the mean pressure difference within the comprehensive control cycle can be controlled within a lower range to a certain extent to slow down the problem of blood regurgitation through the aortic valve.

[0046] pass Figure 2It can be seen that by setting the low-pressure difference control strategy generation submodule, the minimum original target pressure difference corresponding to the original control strategy is obtained; further, the objective function whose function mean is less than the minimum original target pressure difference is used as the low-pressure difference control function, thereby meeting the control requirements of the ventricular assist device while reducing the mean pressure difference within the comprehensive control cycle, effectively reducing the problem of blood regurgitation through the aortic valve.

[0047] Please continue to see Figure 2 In an optional implementation of the embodiment of the present application, the comprehensive control strategy generation module also includes: a control proportion determination submodule.

[0048] In the process of determining the low pressure difference control strategy based on the original control strategy to obtain the comprehensive control strategy, the control proportion submodule is specifically used to: determine the low pressure difference proportion duration of the low pressure difference control strategy within the comprehensive control cycle to obtain a comprehensive control strategy including the original control strategy and the low pressure difference control strategy; wherein the low pressure difference proportion duration is positively correlated with the average value of the low pressure difference control function.

[0049] When using a comprehensive control strategy including the original control strategy and the low pressure difference control strategy to control a ventricular assist device, it is necessary to set the control time of the two control strategies in the entire comprehensive control cycle, that is, their respective control proportions, so as to reduce aortic valve regurgitation while meeting control requirements.

[0050] When under the control of a certain original control strategy, the low pressure difference proportion duration corresponding to the low pressure difference control function is positively correlated with the average value of the low pressure difference control function; that is, the higher the average value of the low pressure difference control function is set, the longer its control duration should be appropriately extended.

[0051] It can be seen from this that the embodiment of the present application determines the proportion of the original control strategy and the low pressure difference control strategy in the entire comprehensive control cycle through the control proportion determination submodule. Only under a reasonable control proportion can it be achieved to both meet the control requirements and reduce the regurgitation through the aortic valve.

[0052] In an optional embodiment, the original control strategy may be a pulsatility-based control strategy.

[0053] If the original control strategy is a control strategy based on pulsation, then in the process of determining the low pressure difference control strategy based on the original control strategy to obtain a comprehensive control strategy: the comprehensive control strategy generation module is used to connect the low pressure difference control strategy in series after the pulsation control function to obtain a comprehensive control strategy; wherein the pulsation control function is a control function of the control strategy based on pulsation.

[0054] It should be noted that the control strategy based on pulsatility can be considered as a characteristic value of heart beat based on the pressure difference between the left ventricle and the aorta, so as to realize the control of ventricular assist device based on the pressure difference, considering the specific intracardiac environment. However, when the patient's heart failure is more serious, the catheter pump needs to provide a higher auxiliary cardiac output to meet the human body's blood supply needs; and high cardiac output means high speed of the pump and high pressure difference between the left ventricle and the aorta; when the pressure difference is high enough, the aortic pressure increases, which may cause the aortic pressure to be higher than the left ventricular pressure, so the valve cannot open, causing a certain degree of structural damage to the patient's aortic valve for a long time. At this time, it is necessary to control the pulsation of the pressure difference to meet the control needs of the left ventricular assist device and improve the problem of the valve not being able to open. Further, the pulsatility of the blood vessel can be understood as the periodic change in axial length of the blood vessel with the pulsation of the pressure in the tube. Since the contraction and relaxation of the heart will drive the regular elastic retraction of the blood vessel to form a corresponding pressure, the pulsatility of the blood vessel is related to the contraction and relaxation of the heart.

[0055] Taking the original control strategy as the control strategy based on pulsation as an example, the method of constructing the original control function is briefly introduced: the current pressure difference is obtained according to the current speed and current current of the motor, and the curve corresponding to the original control function is constructed based on the pulsation of the blood vessels, so as to obtain the target pressure difference corresponding to the current pressure difference, and the control amount for controlling the motor speed is obtained based on the target pressure difference and the current pressure difference, so as to realize the pulsation-based control of the ventricular assist device.

[0056] In the process of constructing the curve corresponding to the original control function, a basic function formula of a pulsating pressure difference function is constructed based on the pulsation principle of blood vessels; since pulsation is periodic and nonlinear, the pulsating pressure difference function in the embodiment of the present application is a periodic nonlinear function, which can conform to pulsation to the greatest extent. Further, the parameters of the basic function formula are adjusted based on physiological laws to obtain the required original control function.

[0057] The parameters that need to be determined include the synchronous control period t, amplitude and deviation adjustment value of the function.

[0058] The synchronous control period T can be determined by the formula T=n*(time / bt). Wherein, bt is the heart rate value, time / bt is the cardiac cycle, and n is a positive integer; illustratively, the cardiac cycle in seconds is generally 60 / bt. It should be noted that the synchronous control period represents the synchronization of the fluctuation of the pulsating pressure difference function with the contraction and relaxation process of the heart.

[0059] The amplitude can be controlled according to the preset pulsatility requirement, so that the difference between the peak and valley values ​​of the pulsating pressure difference function is greater than or equal to the pulsating pressure difference threshold; the amplitude is determined according to the difference between the peak and valley values. The preset pulsatility requirement in the above process can be understood as the minimum difference to ensure the pulsatility of the blood vessels; illustratively, to ensure the pulsatility of the blood vessels, the pressure difference between the high pressure and the low pressure usually needs to be above 20 mmHg. Only when this requirement is met, when the pressure difference is high pressure, the aortic valve is closed, and when the pressure difference is low pressure, the aortic valve is opened, can the aortic valve performance be guaranteed.

[0060] The deviation adjustment value can be determined according to the preset mean range of the pressure difference to determine the deviation adjustment value of the function. It should be noted that the deviation adjustment value of the function is used to ensure that the lowest pressure of the blood vessel does not exceed the low pressure threshold on the basis of the amplitude. The low pressure threshold, that is, the low pressure of the artery, is generally between 60-80 mmHg. When the pressure in the aorta is too low, the blood supply to all parts of the body will be reduced accordingly; it can be understood that the average value of the nonlinear function is above 50 mmHg to ensure that the aortic pressure will not be too low, and the cardiac output can meet the control requirements. Exemplarily, if the original control strategy is a control strategy based on pulsation, its control function is: ΔP set1 =A+Bsin(wt); where, T is the original control cycle of the original control strategy; A and B are variable parameters of the control function. For different gears of the ventricular assist device, the values ​​of A and B may be different; the higher the gear, the faster the motor speed, and the average aortic pressure will increase, so A needs to be continuously increased with the gear. Similarly, the higher the gear, the faster the motor speed, the pulsation of the aorta itself is significantly reduced, and the motor needs to generate greater fluctuations to improve the pulsation of the aorta. Therefore, B also increases with the gear.

[0061] For example, the function form of the curve corresponding to the original control function is ΔP set1 =A+Bsin(wt), since the peak value of the sin function is 1 and the valley value is -1; according to the function requirements provided in the embodiment of the present application, to satisfy the maximum minus minimum amplitude greater than 20, it is only necessary for B to be greater than 10; if B is 20, A represents the average value of the nonlinear function, according to the function requirements provided in the embodiment of the present application, it needs to be greater than 50, such as A is 60.

[0062] Furthermore, if the heart rate bt = 75, then the cardiac cycle is 60 / bt = 0.8; the synchronous cycle of pulsation control = n*cardiac cycle, if n is 3, then the angular frequency That is, the final original control function is ΔP set1 =60+20sin(2.6t), different target pressure differences ΔP can be obtained according to this function set1 .

[0063] For example, the original control function is ΔP set1 =a+b*(t-kT), T is the original control cycle, T=3*cardiac cycle, a is the intercept, which reflects the average value A, and a>A-0.5*b*T; b is the slope, which reflects the change amplitude, and b>B / T. For example, T=2.4, a=40, b=10, the average value within the cycle is (64+40) / 2=52>50, which meets the requirements, and the amplitude is 64-40=24>20, which meets the requirements.

[0064] It should be noted that the control function corresponding to the pulsation-based control strategy can also be other periodic nonlinear functions. The control function provided in the embodiments of the present application is only exemplary and cannot be a limitation on the scope of protection of the present application.

[0065] The pulsation control function corresponding to the original control strategy is ΔP set1 =A+Bsin(wt), the comprehensive control strategy is formed by the pulsation control function followed by the low pressure difference function in series, that is, the comprehensive control function corresponding to the comprehensive control strategy is a piecewise function composed of the pulsation control function and the low pressure difference control function. set1 =A+Bsin(wt) has a minimum value of AB, then the mean value of the low pressure difference control function is smaller than AB. For example, the low pressure difference control function ΔP set2 =C, C is any natural number less than AB. The final pressure difference has the effect of reducing the average value within the comprehensive control cycle to slow down the degree of blood regurgitation through the aortic valve.

[0066] Therefore, the comprehensive control function corresponding to the comprehensive control strategy generated by the control device provided in the embodiment of the present application should be:

[0067]

[0068] Among them, k is a positive integer, T0 is the comprehensive control period, and μ is the proportion control parameter; it can also be seen from the piecewise function that μ can adjust the proportion duration of the low pressure difference.

[0069] Please see Figure 3 , Figure 3 A schematic diagram of a comprehensive control function provided in an embodiment of the present application; Figure 3 The horizontal axis is time, in seconds, and the vertical axis is the pressure difference ΔP set The unit is mmHg. The original control function corresponding to the original control strategy is ΔP set1 =A+Bsin(wt), low pressure difference function is ΔP set2=C, μ determines the proportion of pulsation control and low pressure difference control in the whole comprehensive control cycle. When μ is too small, it means that the proportion of low pressure difference is large. At this time, the pulsation effect is weak and cannot provide enough cardiac output. When μ is too large, the proportion of pulsation control is large and the regurgitation through the aorta is more. It has been verified that the optimal value range of μ is 0.6-0.8.

[0070] exist Figure 3 If T0 = 4, μ = 0.6, that is, 4s is a control cycle, and the first 2.4s in the cycle is ΔP set1 , ΔP at 2.4s-4s set2 ; Figure 3 The low pressure control function takes 10 mmHg and is updated again after 4 seconds.

[0071] It should be noted that the embodiments of the present application Figure 3 The proportion relationship function provided in is only exemplary. In practical applications, ΔP set1 and ΔP set2 It can be diverse. The sine function and the constant function are not fixed function forms.

[0072] In some embodiments, the low pressure control function can also be ΔP set2 =A-1.1B+Bsin(wt); then the comprehensive control function corresponding to the comprehensive control strategy is:

[0073]

[0074] The average value of the low-pressure control function in series is lower than the lowest value of the original control function. The comprehensive control function corresponding to the comprehensive control strategy after series connection is not unique or fixed, as long as the speed can be reduced.

[0075] It should be noted that the average value of the low-pressure control function can be very low in theory, but when it is low to a certain level, the blood pressure lowering effect will not be obvious due to the limitations of the intracardiac environment.

[0076] In some embodiments, the pulsation control function is ΔP set1 =A+Bsin(wt) as an example, after the low pressure difference function is connected in series after the pulsation control function, the cardiac output generated in the whole comprehensive control cycle may be insufficient to meet the cardiac output requirement; in this case, the A value can be appropriately increased to compensate for the loss of cardiac output caused by the low pressure difference.

[0077] In some embodiments, the pulsation control function is ΔP set1=A+Bsin(wt) as an example, in the first half of the sine function (higher amplitude), reflux is more likely to occur than with the ordinary constant pressure difference control strategy; therefore, in order to quickly reduce the aortic pressure, it is more necessary to connect a low pressure difference control function in series after the pulsation control function.

[0078] It can be seen that when the original control strategy is a control strategy based on pulsation, a low-pressure difference control function is connected in series after the pulsation control function corresponding to the pulsation-based control strategy, so as to obtain a comprehensive control strategy; further, the control ratio relationship between the pulsation control function and the low-pressure difference control function is adjusted. When the control ratio parameter is relatively small, it means that the proportion of the low pressure difference is relatively large. At this time, the pulsation effect is relatively weak and cannot provide enough cardiac output; when the control ratio parameter is relatively large, the pulsation control ratio is relatively large, and the aortic reflux is more; therefore, by adjusting the control ratio parameter, the aortic reflux can be controlled.

[0079] In an optional embodiment, in the process of controlling the motor speed of the ventricular assist device with a comprehensive control strategy within a comprehensive control cycle, the motor control module is specifically used to: within the comprehensive control cycle, control the motor speed with the original target pressure difference corresponding to the original control strategy within the original control proportion time, and control the motor speed with the target low pressure difference corresponding to the low pressure control strategy within the low pressure difference proportion time; wherein the original control proportion time and the low pressure difference proportion time constitute a comprehensive control cycle.

[0080] It should be noted that the integrated control cycle is an integer multiple of the human cardiac cycle. In order to meet the pulsatility requirements, the integrated control cycle conforms to the heart rate cycle while reducing aortic regurgitation under high pressure difference conditions.

[0081] In the comprehensive control cycle, the motor speed is controlled by the original control strategy and the low-pressure difference control strategy respectively; the target pressure difference corresponding to the comprehensive control function composed of the original control strategy and the low-pressure difference control strategy is subtracted from the current pressure difference to obtain the pressure difference difference; the calculated pressure difference difference is sent to a controller, such as a PI controller, a PID controller, etc.; the control quantity for controlling the motor speed is obtained, and the speed of the electrode is controlled based on the control quantity.

[0082] In an optional embodiment, the current pressure difference can be obtained by acquiring the current speed and current current of the motor; after acquiring the current speed and current current, the speed signal corresponding to the current speed is filtered, and the current pressure difference is determined based on the filtered current speed and current current.

[0083] Due to the nonlinearity of the pump itself, the Extended Kalman Filter (EKF) algorithm can be used to estimate the current pressure difference from the noisy speed signal.

[0084] It should be noted that it is an extended form of the standard Kalman filter in the nonlinear case. The EKF algorithm Taylor expands the nonlinear function, omits the high-order terms, and retains the first-order terms of the expanded terms to achieve the linearization of the nonlinear function. Finally, the Kalman filter algorithm is used to approximate the state estimate and variance estimate of the system to filter the signal. The extended Kalman filter is an improvement of the Kalman filter, and the model form is:

[0085] x k =f(x k-1 ,u k )+w k

[0086] z k =h(x k )+v k

[0087] Among them, x k is the state value at time k, x k-1 is the state value at time k-1, u k is the control input at time k, w k 、v k is the interference at time k, z k is the measured value at time k.

[0088] The pressure difference can be calculated or estimated based on the current speed and current current through the HQ curve. It should be noted that the use of the extended Kalman filter to filter the speed signal in the above process is only exemplary, and other filters can be selected to achieve filtering, such as Wiener filters, adaptive filters, etc.; the selection of filters cannot be a limitation on the protection scope of the embodiments of this application.

[0089] It can be seen that the motor control module obtains the pressure difference value by subtracting the target pressure difference corresponding to the comprehensive control function composed of the original control strategy and the low pressure difference control strategy from the current pressure difference; the control quantity for controlling the motor is generated based on the pressure difference value, and the motor is controlled by the control quantity. Due to the existence of the low pressure difference control function, the average pressure difference within the cycle can be effectively reduced, thereby improving the aortic regurgitation problem.

[0090] In an optional embodiment, the integrated control generation module is further configured to receive a reverse flow signal before determining the low pressure difference control strategy based on the original control strategy to obtain the integrated control strategy.

[0091] Aortic regurgitation can be monitored by a regurgitation detection device or a regurgitation detection module. When the aortic regurgitation exceeds a threshold, the regurgitation detection device or module can send a regurgitation signal. When the control device provided in the embodiment of the present application receives the regurgitation signal, the motor speed of the ventricular assist device can be controlled by a comprehensive control strategy, so that the aortic regurgitation can be reduced in time.

[0092] Exemplarily, the blood vessel pressure value can be detected, and when the blood vessel pressure value exceeds the pressure threshold, the motor speed of the ventricular assist device can be controlled by the above-mentioned comprehensive control strategy; wherein, the blood vessel pressure detection can be achieved by ultrasonic detection and other methods.

[0093] Please see Figure 4 , Figure 4 A schematic diagram of the system architecture of a ventricular assist system provided in an embodiment of the present application; a second aspect of the present application provides a ventricular assist system, which includes a control device and a ventricular assist device provided in the first aspect of the present application.

[0094] The control device is used for determining the low pressure difference control strategy according to the original control strategy to obtain the comprehensive control strategy.

[0095] The control device is also used to control the motor speed of the ventricular assist device according to a comprehensive control strategy.

[0096] Please see Figure 4 , Figure 4 A flowchart of a control method provided in an embodiment of the present application; a third aspect of the present application further provides a control method, the control method is used to control a control device of a ventricular assist device; the control device includes a comprehensive control strategy generation module and a motor control module. The control method includes the following steps:

[0097] Step S100: The comprehensive control strategy generation module determines a low pressure difference control strategy based on the original control strategy to obtain a comprehensive control strategy.

[0098] Step S101: The motor control module controls the motor speed of the ventricular assist device using a comprehensive control strategy within a comprehensive control cycle.

[0099] In the above steps S100-S101, the integrated control strategy generation module determines the low pressure difference control strategy based on the original control cycle, thereby obtaining an integrated control strategy including the original control strategy and the low pressure difference control strategy. Further, the motor control module controls the motor speed of the ventricular assist device with the integrated control strategy within the integrated control cycle.

[0100] pass Figure 4It can be seen that the control method provided by the embodiment of the present application can generate a low pressure difference control strategy based on the original control strategy; the motor speed of the ventricular assist device is controlled by a comprehensive control strategy including the original control strategy and the low pressure difference control strategy. Due to the setting of the low pressure difference control strategy, the vascular pressure difference generated by the original control strategy is reduced, thereby improving the aortic valve regurgitation problem.

[0101] See also Figure 5 , Figure 5 The electronic device 300 provided in the embodiment of the present application includes: a processor 301 and a memory 302, wherein the memory 302 stores machine-readable instructions executable by the processor 301, and when the machine-readable instructions are executed by the processor 301, the above method is executed.

[0102] Based on the same inventive concept, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer program instructions, and when the computer program instructions are read and executed by a processor, the steps in any of the above implementation methods are executed.

[0103] The computer-readable storage medium may be a random access memory (RAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or any other medium that can store program codes. The storage medium is used to store the program, and the processor executes the program after receiving the execution instruction. The method executed by the electronic terminal of the process definition disclosed in any embodiment of the present invention can be applied to the processor or implemented by the processor.

[0104] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0105] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0106] Furthermore, the functional modules in the various embodiments of the present application 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.

[0107] Alternatively, the present invention may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented by software, the present invention may be implemented in whole or in part in the form of 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, the process or function described in the embodiment of the present invention is generated in whole or in part.

[0108] The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0109] In this article, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0110] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A control device, characterized in that: The control device is used to control a ventricular assist device; The control cycle of the control device is a comprehensive control cycle; the control device comprises: a comprehensive control strategy generation module and a motor control module; The comprehensive control strategy generation module is used to determine the low pressure difference control strategy based on the original control strategy to obtain the comprehensive control strategy; wherein the original control strategy is used to maintain the cardiac output within the comprehensive control cycle; and the low pressure control strategy is used to reduce the vascular pressure generated by the original control strategy; The motor control module is used to control the motor speed of the ventricular assist device according to the comprehensive control strategy within the comprehensive control cycle.

2. The device according to claim 1, characterized in that The comprehensive control strategy generation module includes: a low-voltage control strategy generation submodule; In the process of determining the low pressure difference control strategy based on the original control strategy, the low pressure control strategy generation submodule is specifically used for: Obtaining the minimum value of the original target pressure difference corresponding to the original control strategy; and The objective function whose function average value is less than the minimum value of the original target pressure difference is determined as the low-pressure control function of the low-pressure control strategy.

3. The device according to claim 2, characterized in that The comprehensive control strategy generation module also includes: a control proportion determination submodule; In the process of determining the low pressure difference control strategy based on the original control strategy to obtain the comprehensive control strategy, the control proportion submodule is specifically used for: Determine the low pressure difference proportion duration of the low pressure control strategy within the comprehensive control cycle to obtain the comprehensive control strategy including the original control strategy and the low pressure difference control strategy; wherein the low pressure difference proportion duration is positively correlated with the average value of the low pressure difference control function.

4. The device according to claim 3, characterized in that The original control strategy includes a control strategy based on pulsation; In the process of determining the low pressure difference control strategy based on the original control strategy to obtain the comprehensive control strategy: The comprehensive control strategy generation module is used to connect the low pressure difference control strategy in series after the pulsation control function to obtain the comprehensive control strategy; wherein the pulsation control function is the control function of the pulsation-based control strategy.

5. The device according to claim 1, characterized in that In the process of controlling the motor speed of the ventricular assist device by the comprehensive control strategy within the comprehensive control cycle, the motor control module is specifically used to: During the comprehensive control cycle, the motor speed is controlled by the original target pressure difference corresponding to the original control strategy within the original control proportion time, and the motor speed is controlled by the target low pressure difference corresponding to the low pressure control strategy within the low pressure difference proportion time; wherein, the original control proportion time and the low pressure difference proportion time constitute a comprehensive control cycle; the comprehensive control cycle is an integer multiple of the human heart rate cycle.

6. The device according to claim 1, characterized in that The integrated control generation module is further configured to receive a reverse flow signal before determining the low pressure difference control strategy based on the original control strategy to obtain the integrated control strategy.

7. A ventricular assist system, characterized in that: The ventricular assist system comprises: a control device and a ventricular assist device as described in any one of claims 1 to 6; The control device is used to determine the low pressure difference control strategy according to the original control strategy to obtain a comprehensive control strategy; The control device is also used to control the motor speed of the ventricular assist device according to the comprehensive control strategy.

8. A control method, characterized in that: The control method is used to control a control device of a ventricular assist device; the control device comprises a comprehensive control strategy generation module and a motor control module; the method comprises: The comprehensive control strategy generation module determines a low pressure difference control strategy based on the original control strategy to obtain a comprehensive control strategy; wherein the original control strategy is used to maintain the cardiac output within the comprehensive control cycle; and the low pressure control strategy is used to reduce the vascular pressure generated by the original control strategy; The motor control module controls the motor speed of the ventricular assist device according to the comprehensive control strategy within the comprehensive control cycle.

9. An electronic device, characterized in that: The electronic device comprises a memory and a processor, wherein program instructions are stored in the memory, and when the processor runs the program instructions, the steps in the method of claim 8 are executed.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the steps in the method of claim 8 are executed.

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