Adaptive control method and device

Abstract

The application provides an adaptive control method and device. The method comprises the following steps: acquiring a plurality of pumping flows of a ventricular assist device when the ventricular assist device runs at a first rotating speed in a first period; recording a first time length and a second time length, the first time length being a time length of adjacent first pumping flow intervals, and the second time length being a time length of the first pumping flow being less than a first flow threshold in the first time length, the first pumping flow being a peak value of the pumping flow of the ventricular assist device; and adjusting the first rotating speed according to a target ratio, the target ratio being a ratio of the second time length to the first time length. According to the first time length and the second time length, the heart cycle of a user and the low flow value of the ventricular assist device can be determined, the rotating speed of the ventricular assist device is adjusted according to the ratio of the second time length to the first time length, so that the pumping flow of the ventricular assist device can meet the demand of the user in real time, the abnormality of the ventricular assist device is reduced, and the safety of the user is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, and in particular to a self-adaptive control method and device. BACKGROUND

[0002] A ventricular assist device is an effective means for treating heart failure patients, and is an artificial mechanical device that partially or completely replaces the ventricle to perform work by pumping fluid from the venous system or the heart directly into the arterial system.

[0003] A ventricular assist device is driven by a motor to suspend rotation of an impeller arranged in a housing assembly to pump blood from the left ventricle to the aorta or to pump blood from the right ventricle to the pulmonary artery. Currently, the rotational speed of the ventricular assist device is generally constant at a set rotational speed, but because the user has different needs for output in different states, the pumping flow of the ventricular assist device may not match the current condition of the user, and this mismatch causes abnormalities that can damage the patient's heart and exacerbate the patient's condition. SUMMARY

[0004] Embodiments of the present application provide a self-adaptive control method and device that can adaptively adjust the rotational speed to make the pumping flow of the ventricular assist device meet the condition needs of the user in real time.

[0005] In a first aspect, embodiments of the present application provide a self-adaptive control method applied to a ventricular assist device, and the method comprises:

[0006] obtaining a plurality of pumping flows of the ventricular assist device when the ventricular assist device runs at a first rotational speed in a first period;

[0007] recording a first duration and a second duration, the first duration being a duration of adjacent first pumping flow intervals, and the second duration being a duration of the first pumping flow being less than a first flow threshold in the first duration, the first pumping flow being a peak value of the pumping flow of the ventricular assist device;

[0008] adjusting the first rotational speed according to a target ratio, the target ratio being a ratio of the second duration to the first duration.

[0009] In a second aspect, embodiments of the present application provide a control device of a ventricular assist device, and the control device comprises one or more processors, and the one or more processors are configured to:

[0010] obtain a plurality of pumping flows of the ventricular assist device when the ventricular assist device runs at a first rotational speed in a first period;

[0011] record a first duration and a second duration, the first duration being a duration of an adjacent first pumping flow interval, the second duration being a duration of the first pumping flow being the pumping flow less than a first flow threshold within the first duration, the first pumping flow being a peak value of the pumping flow of the ventricular assist device;

[0012] adjust the first rotation speed according to a target ratio, the target ratio being a ratio of the second duration to the first duration.

[0013] In a third aspect, an embodiment of the present application provides a ventricular assist device, the ventricular assist device comprising:

[0014] a housing;

[0015] an impeller arranged in the housing;

[0016] a control unit configured to control rotation of the impeller, the control unit being configured to perform some or all of the steps described in the method of the first aspect.

[0017] In a fourth aspect, an embodiment of the present application provides a medical device, the medical device comprising a processor, a memory, a communication interface, and one or more programs stored in the memory and configured to be executed by the processor, the program comprising instructions for performing some or all of the steps described in the method of the first aspect.

[0018] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium storing a computer program for electronic data exchange, wherein the computer program causes a computer to perform some or all of the steps described in the method of the first aspect.

[0019] In a sixth aspect, an embodiment of the present application provides a computer program product, wherein the above computer program product includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to perform some or all of the steps described in the method of the first aspect of the present application. The computer program product can be a software installation package.

[0020] The technical scheme provided in the application obtains a plurality of pumping flows of the ventricular assist device when the ventricular assist device operates at a first rotating speed in a first period; records a first time length and a second time length, the first time length is a time length of adjacent first pumping flow intervals, and the second time length is a time length of the first pumping flow being less than a first flow threshold in the first time length, and the first pumping flow is a peak value of the pumping flow of the ventricular assist device; and if the first rotating speed is adjusted according to a target ratio, the target ratio is a ratio of the second time length to the first time length. According to the first time length and the second time length, the heart cycle of the user and the low flow value of the ventricular assist device can be determined respectively, the rotating speed of the ventricular assist device is adjusted adaptively through the ratio of the second time length to the first time length, so that the pumping flow of the ventricular assist device can meet the user demand in real time, the abnormality of the ventricular assist device is reduced, and the safety of the user is improved. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0022] Figure 1 is a structural schematic diagram of a ventricular assist device provided by an embodiment of the present application;

[0023] Figure 2 is a schematic diagram of a ventricular assist device provided by an embodiment of the present application located at a normal position of a patient's heart;

[0024] Figure 3 is a flow schematic diagram of an adaptive control method provided by an embodiment of the present application;

[0025] Figure 4 is a structural schematic diagram of a medical device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order for those skilled in the art to better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the description of the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0027] The terms "first", "second", "third", etc. in the specification and claims of this application and in the above drawings are used to distinguish different objects, and are not used to describe a particular order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, software, product or device including a series of steps or units is not limited to the listed steps or units, but also includes steps or units not listed, or further includes other steps or units inherent to the process, method, product or device.

[0028] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] The medical device and the pump involved in the present application can be a ventricular assist device (VAD), such as an implantable ventricular assist device, an interventional ventricular assist device, etc. The ventricular assist device can include at least one blood pump, wherein the blood pump can be a centrifugal pump, an axial flow pump, a magnetic suspension pump, etc.

[0030] In the present application, "current" refers to the current driving the motor or the electric machine, which is associated with the power of the motor or the electric machine when the power supply voltage is constant. "Rotational speed" refers to the rotational speed of the motor or the electric machine, which is associated with the rotational speed of the rotor or the impeller of the ventricular assist device, and can be defined as revolutions per minute. "Flow", "fluid flow", "pumping flow" refers to the volume of fluid transported through the ventricular assist device per unit of time, which can be measured in liters per minute.

[0031] It should be noted that in the present application, the term "proximal" or "proximal side" refers to the end or side closer to the operator, and "distal" or "distal side" refers to the end or side farther from the operator.

[0032] Please refer to Figures 1-2 , Figure 1 is a structural schematic diagram of a ventricular assist device 100 provided by an embodiment of the present application, Figure 2 is a schematic diagram of a ventricular assist device 100 located in a normal position of a user's heart 120. The ventricular assist device 100 can operate in any other suitable position in the user's left heart, right heart, outside the heart, partially outside the heart, partially outside the vascular system, or in the vascular system. For example, the present application is described by taking the ventricular assist device 100 as an example of being placed in the left heart.

[0033] The ventricular assist device 100 can be inserted percutaneously through the femoral artery 122 into the aorta 124 and through the aorta 124 into the left ventricle 128. Alternatively, the ventricular assist device can be inserted percutaneously through the axillary artery 123 into the aorta 124 and through the aorta 124 into the left ventricle. In other embodiments, the ventricular assist device 100 can also be inserted directly into the aorta 124 and through the aorta 124 into the left ventricle 128. During operation, the ventricular assist device 100 pumps blood from the left ventricle 128 into the aorta 124.

[0034] The ventricular assist device 100 includes a cannula 10. The cannula 10 has a proximal end and a distal end, the distal end of the cannula 10 having a fluid inlet 101 and the proximal end of the cannula 10 having a fluid outlet 102, blood flowing from the fluid inlet 101 into the fluid outlet 102 through the cannula 10.

[0035] The ventricular assist device 100 includes an impeller (not shown). The impeller is at least partially located at the proximal end of the cannula 10, such as at the fluid outlet 102 of the cannula 10, such that when the ventricular assist device 100 is operating, the impeller is driven to rotate to pump blood from the left ventricle 128 into the aorta 124.

[0036] The ventricular assist device 100 can include a motor (not shown), which can be located inside the ventricular assist device 100 or outside the ventricular assist device 100. The embodiments of the present application are described with the motor located inside the ventricular assist device 100, such as in a motor housing 201, the distal end of the motor housing 201 connected to the proximal end of the cannula 10. The motor drives the impeller to rotate by driving the drive shaft to rotate, thereby achieving the blood pumping function of the ventricular assist device 100.

[0037] The ventricular assist device 100 includes a catheter 30, the distal end of the catheter 30 connected to the proximal end of the motor housing 201, and the drive cable can extend through the catheter 30. For example, the catheter 30 can accommodate the electrical leads connecting the ventricular assist device 100 to an external controller. For example, the ventricular assist device 100 further includes a distal component 110 extending distally from the distal end of the cannula 10, such as a pigtail.

[0038] The ventricular assist device 100 also includes a control unit that can be used to perform any of the embodiments, aspects, and methods of the present application. The control unit can be disposed internally within the ventricular assist device 100 or externally from the ventricular assist device 100. The control unit is used to detect relevant parameters of the ventricular assist device 100 and the user, as well as control the operation of the ventricular assist device 100, for example, the control unit supplies current to the motor through one or more wires and detects the current through a current detection circuit (e.g., a phase current detection circuit); estimates the current flow rate based on the received current, controls the rotation speed of the ventricular assist device 100 according to the received instructions; and further detects whether there are suction, regurgitation and other abnormal events according to the pump flow rate and rotation speed, etc.

[0039] The ventricular assist device 100 is placed such that the cannula 10 extends across the aortic valve 126 of the user, with the distal end of the cannula 10 located in the left ventricle 128 of the user and the proximal end of the cannula 10 located in the aorta 124 of the user.

[0040] In combination with the above description, the present application is described below from the perspective of method examples.

[0041] Please refer to Figure 3 , Figure 3 An adaptive control method flow diagram is provided for an embodiment of the present application, which is applied to a ventricular assist device as shown in Figure 1 and Figure 2 As shown in Figure 3 , the method comprises the following steps.

[0042] S310, obtaining a plurality of pump flow rates of the ventricular assist device when the ventricular assist device operates at a first rotation speed in a first period.

[0043] In the process of the ventricular assist device 100 operating in the user's body, the pump flow rate through the ventricular assist device 100 depends on the work that the ventricular assist device 100 needs to overcome the resistance to pump blood from the left ventricle 128 to the aorta 124. The work of the ventricular assist device 100 can be quantified as the current size that needs to be provided to the motor, that is, the motor current corresponds to the amount of current delivered to the motor of the ventricular assist device 100 when the ventricular assist device 100 operates in the user. During different phases of the cardiac cycle of the user's heart, the load of the motor will change. When the pressure difference in the user's heart changes, the motor current will also change to keep the rotor speed constant. For example, when the flow rate of blood into the aorta 124 increases (such as during cardiac contraction), the current required by the motor will increase. Therefore, the change in motor current can thus help characterize the heart performance. That is, during the operation of the ventricular assist device 100, the ventricular assist device 100 has a current-flow characteristic curve, wherein the greater the current, the greater the work of the ventricular assist device 100, that is, the greater the pump flow rate of the ventricular assist device 100.

[0044] The current of the ventricular assist device 100 can be measured by a phase current detection circuit or any other suitable means (such as a current sensor). The current-flow characteristic curve can be pre-stored in the control unit. Before the ventricular assist device 100 is shipped, the current-flow characteristic curve of the ventricular assist device 100 at different rotation speeds can be tested in a test system, and then the current-flow characteristic curve can be stored in the control unit. The control unit can store the detected current in real time.

[0045] Specifically, when the ventricular assist device 100 is running at the first rotation speed, the control unit obtains the current curve in the first period, and then estimates the flow curve corresponding to the current curve using the pre-stored current-flow characteristic curve. The plurality of pumping flows can be pumping flows collected from the flow curve at sampling intervals. The first period is greater than the heart cycle of a normal person. For example, the first period can be m times of the heart cycle, and m can be 10, 20, 30, etc.

[0046] S320, record the first duration and the second duration, the first duration is the duration of adjacent first pumping flow intervals, and the second duration is the duration of the first pumping flow to the pumping flow less than the first flow threshold in the first duration. The first pumping flow is the peak value of the pumping flow of the ventricular assist device.

[0047] Wherein, in the ventricular systole, the aortic valve 126 or the pulmonary valve is opened, the blood in the ventricle is pumped to the aorta 124 or the pulmonary artery, the blood volume in the ventricle gradually decreases, and the ventricle also gradually decreases; in the ventricular diastole, the mitral valve or the tricuspid valve is opened, the blood in the atrium flows to the ventricle, the blood volume in the ventricle gradually increases, and the ventricular pressure also gradually increases. Therefore, in the ventricular systole, the blood in the ventricle is pumped to the aorta 124 or the pulmonary artery, and the pumping flow of the ventricular assist device 100 gradually decreases to a minimum value; in the ventricular diastole, the blood in the atrium flows to the ventricle, the blood volume in the ventricle gradually increases, and the pumping flow of the ventricular assist device 100 gradually increases to a maximum value. That is, the fluctuation of the pumping flow of the ventricular assist device 100 is synchronized with the heart cycle of the user, and therefore the change of the pumping flow of the ventricular assist device 100 can reflect the current heart condition of the user.

[0048] The heart cycle of the user can be determined by adjacent peaks or adjacent valleys of the pumping flow of the ventricular assist device 100, i.e., the heart cycle of the user is determined by the time interval between adjacent first pumping flows of the ventricular assist device 100. In the ventricular systole, the pumping flow of the ventricular assist device 100 reaches the minimum, and the control unit can determine the time interval during which the pumping flow of the ventricular assist device 100 is low according to the second time interval. The systole and diastole in the heart cycle of the user are fixed, i.e., the change trend and change time of the pumping flow of the ventricular assist device 100 in a heart cycle are fixed. When the second time interval exceeds the preset time interval, it can be considered that the current pumping flow of the ventricular assist device 100 is out of synchronization with the heart cycle of the user. Therefore, the control unit can determine the heart cycle of the user by the first time interval, and determine whether the current pumping flow of the ventricular assist device 100 is synchronized with the heart cycle of the user by the second time interval, and then synchronize the pumping flow of the ventricular assist device 100 by adjusting the rotating speed of the ventricular assist device 100 when it is out of synchronization.

[0049] S330, adjusting the first rotating speed according to a target ratio, the target ratio being a ratio of the second time interval to the first time interval.

[0050] In the present application, the ratio of the second time interval to the first time interval can determine the proportion of low pumping flow in the entire heart cycle, and the size of the target ratio can determine whether the ventricular assist device 100 is running abnormally, and then the first rotating speed is adjusted to solve the abnormal situation.

[0051] Optionally, the adjusting the first rotating speed according to the target ratio comprises: if the target ratio is greater than a first target value, sequentially increasing the first rotating speed until the first rotating speed is increased by n rotating speed steps or a difference between a first average flow and a second average flow is greater than a second flow threshold, the first average flow being an average value of the pumping flow in the first cycle, the second average flow being an average value of the pumping flow in the second cycle, the first cycle being earlier than the second cycle, and the n being a positive integer; if the target ratio is less than a second target value, sequentially decreasing the first rotating speed until the first rotating speed is decreased by the n rotating speed steps or the difference between the second average flow and the first average flow is greater than the second flow threshold.

[0052] The fluctuation of the pump flow of the ventricular assist device 100 is synchronized with the cardiac cycle, so the length of time in which the pump flow of the ventricular assist device 100 is less than the first flow threshold in a cardiac cycle is within a fixed range. When the target ratio of the second length to the first length is greater than the first target value, the ventricular assist device 100 is in low pump flow for too long, indicating that the left ventricular pressure of the current user is too low or the aortic pressure is too high, and the reverse flow problem or the unloading deficiency problem caused by the too low speed of the ventricular assist device 100, so the control unit can control to increase the speed of the ventricular assist device 100 to reduce or solve the reverse flow or unloading deficiency problem of the ventricular assist device 100. When the target ratio of the second length to the first length is less than the second target value, the ventricular assist device 100 is in low pump flow for too short, indicating that the left ventricular pressure of the current user is too high or the aortic pressure is too low, and the excessive unloading problem or the suction problem caused by the too high speed of the ventricular assist device 100, so the control unit can control to reduce the speed of the ventricular assist device 100 to reduce or solve the excessive unloading problem or the suction problem of the ventricular assist device 100.

[0053] When it is determined according to the target ratio that the current ventricular assist device 100 has reverse flow or unloading deficiency, the control unit can automatically control to increase the speed of the ventricular assist device 100 in turn. Specifically, the control unit first increases the first speed by a speed step △v, and runs for a first period of time, calculates the target ratio in the period, if the target ratio is still greater than the first target value, continues to increase the speed step △v, until the speed step △v is increased n times, or the average of the pump flow in the period is increased by the second flow threshold than the average of the pump flow in the last period. That is, when it is detected that there is a reverse flow problem or an unloading deficiency, the control unit automatically controls to increase the speed step △v, until the number of increases n is reached, or the ventricular assist device 100 does not have a reverse flow problem or an unloading deficiency, or the pump flow of the ventricular assist device 100 is improved.

[0054] When it is determined according to the target ratio that the current ventricular assist device 100 has reverse flow or unloading deficiency, the control unit can automatically control to increase the speed of the ventricular assist device 100 in turn. Specifically, the control unit first increases the first speed by a speed step △v, and runs for a first period of time, calculates the target ratio in the period, if the target ratio is still greater than the first target value, continues to increase the speed step △v, until the speed step △v is increased n times, or the average of the pump flow in the period is increased by the second flow threshold than the average of the pump flow in the last period. That is, when it is detected that there is a reverse flow problem or an unloading deficiency, the control unit automatically controls to increase the speed step △v, until the number of increases n is reached, or the ventricular assist device 100 does not have a reverse flow problem or an unloading deficiency, or the pump flow of the ventricular assist device 100 is improved.

[0055] The first target value and the second target value can be set according to the heart cycle of the user, for example, the first target value is set to 0.23, 0.25, 0.28, etc., and the second target value is set to 0.1, 0.15, 0.18, etc. The first flow threshold is less than the second flow threshold. For example, the first flow threshold is set to 0, and the second flow threshold is set to 1 LPM. For example, the first flow threshold is set to 0.3 LPM, and the second flow threshold is set to 1 LPM. The speed step Δv can be determined according to the size of the first speed and the operating speed range allowed by the ventricular assist device 100. The larger the first speed and the closer the first speed is to the nearest boundary value of the operating speed range, the larger the speed step Δv. For example, the operating speed range is 23000 RPM-46000 RPM, if the first speed is 40000 RPM, if it is determined that the first speed is too high and needs to be reduced, the speed step Δv can be determined to be 4000 RPM. If the first speed is 25000 RPM, if it is determined that the first speed is too low and needs to be increased, the speed step Δv can be determined to be 4000 RPM. If the first speed is 35000 RPM, if it is determined that the first speed is too low and needs to be increased, the speed step Δv can be determined to be 1000 RPM. Wherein n can be set to 3, 4, 5, 6, etc.

[0056] In this application, the control unit monitors whether the current ventricular assist device 100 is operating abnormally through the fluctuation of the pump flow of the ventricular assist device 100, and then automatically controls to increase the speed of the ventricular assist device 100 when the ventricular assist device 100 is operating abnormally, so as to reduce or avoid the harm caused by the abnormal operation of the ventricular assist device 100 in time, and improve the safety of the user.

[0057] For example, the method further comprises: determining a second pump flow and a target number, the target number being the number of pump flows less than the first flow threshold in the first time length, and the second pump flow being the smallest pump flow in the first time length; if the second pump flow is less than a third flow threshold, and the target number is greater than or equal to a first value, it is determined that the ventricular assist device has regurgitation and an alarm is given.

[0058] Blood regurgitation refers to the phenomenon of blood flowing in the opposite direction of normal blood flow, for example, the normal direction of blood flow is that the blood in the left ventricle 128 flows into the aorta 124, and when a large amount of blood in the aorta 124 flows back into the left ventricle 128, it indicates that blood regurgitation occurs. Blood regurgitation is the flow of blood from the aorta 124 to the left ventricle 128 through the ventricular assist device 100, at this time the pump flow of the ventricular assist device 100 is low or even negative. When the pump flow of the ventricular assist device 100 is not synchronized with the heart cycle, for example, when the speed of the ventricular assist device 100 is too low and the left ventricular pressure is too high, blood regurgitation is prone to occur. Regurgitation can cause the user to have complications such as increased ventricular size and blood loss, and prolonged regurgitation can seriously endanger the health of the user.

[0059] Based on this, the control unit can also monitor in real time whether there is a regurgitation problem during the operation of the ventricular assist device 100. Specifically, the control unit divides the plurality of pumping flows into a plurality of cardiac cycles according to the adjacent first pumping flow. Then, the number of pumping flows less than the first flow threshold value in each cardiac cycle and the minimum pumping flow (second pumping flow) in the cardiac cycle are recorded respectively. If the second pumping flow is less than the third flow threshold value and the target number is greater than or equal to the first value, it is considered that the current ventricular assist device 100 has a regurgitation phenomenon, and the control unit can alarm to inform medical staff to take measures as soon as possible. The third flow threshold value can be set to 0.5 LPM.

[0060] Further, to improve the accuracy of monitoring and the sensitivity of the alarm, the control unit can continuously monitor the second pumping flow and the target number in the first cycle. If the second pumping flow in the first cycle is continuously less than the third flow threshold value and the target number is continuously greater than or equal to the first value, it is confirmed that the current ventricular assist device 100 has a regurgitation phenomenon and an alarm is given.

[0061] Wherein, when confirming that the ventricular assist device 100 has a regurgitation phenomenon and giving an alarm, the control unit can reduce or solve the regurgitation problem by increasing the rotation speed. Specifically, the first rotation speed is increased by a rotation speed step △v and operated for a length of the first cycle, and then it is judged whether there is a regurgitation phenomenon. If the regurgitation phenomenon still exists, the rotation speed step △v is increased again and operated for a length of the first cycle. According to this method, until the ventricular assist device 100 does not have a regurgitation phenomenon, or the number of times of increasing the first rotation speed exceeds n, or the average pumping flow of the ventricular assist device 100 increases by a second flow threshold value.

[0062] Further, if the average pumping flow of the ventricular assist device 100 increases by more than a third flow threshold value during the continuous increase of the first rotation speed, the control unit can control to stop the alarm while reducing the rotation speed of the current ventricular assist device 100. The reduced rotation speed step can be set to the above-mentioned △v.

[0063] In a possible embodiment, the method further comprises: obtaining a target characteristic curve, the target characteristic curve being a pressure-flow characteristic curve of the ventricular assist device; determining a first pressure difference corresponding to a first average flow at the first rotation speed according to the target characteristic curve, the first average flow being an average value of the plurality of pumping flows in the first cycle, and the first pressure difference being a difference between the pressure at the outlet and the pressure at the inlet of the ventricular assist device; if the first pressure difference is less than a first pressure threshold value or the first pressure difference is greater than a second pressure threshold value, determining that the blood pressure of the target user is abnormal and giving an alarm, the target user being a user implanted with the ventricular assist device.

[0064] During the operation of the ventricular assist device 100, the user's ventricular pressure difference can be too low (e.g., the left ventricular pressure is too high or the aortic pressure is too low), or the user's ventricular pressure difference can be too high (e.g., the left ventricular pressure is too low or the aortic pressure is too high). The user's ventricular pressure being too high or too low can cause the pump flow of the ventricular assist device 100 to be mismatched with the output demand of the left heart, resulting in problems such as excessive unloading, suction, excessive pre-charge, and the like of the left ventricle 128.

[0065] Based on this, the control unit can monitor the pressure difference of the left ventricle 128 in real time during the operation of the ventricular assist device 100, and early detect abnormal user blood pressure or abnormal ventricular assist device 100, and issue an alarm to prompt early medical treatment, thereby improving the success rate of treatment.

[0066] The aortic pressure being too high can be caused by the blood vessel resistance being too large and the blood pressure being high, and the blood accumulating in the left ventricle 128 and being unable to be pumped to the aorta 124. The user's left ventricular pressure being too low can be caused by the rotational speed of the ventricular assist device 100 being too high, resulting in the blood volume in the left ventricle 128 being too small, or the blood volume in the left ventricle 128 being too small due to systemic hypovolemia or right heart failure. The user's aortic pressure being too low or the left ventricular pressure being too high can be caused by the rotational speed of the ventricular assist device 100 being too low, resulting in the blood volume in the left ventricle 128 being too large.

[0067] In the present application, before the ventricular assist device 100 is shipped, the ventricular assist device 100 can be placed in a test environment to measure the pressure-flow characteristic curve of the pump flow and the ventricular pressure difference at different rotational speeds. Then the pressure-flow characteristic curve at each rotational speed is stored in the control unit. When the ventricular assist device 100 is operating, the current rotational speed and pump flow of the ventricular assist device 100 are obtained, and then the current left ventricular pressure difference is estimated according to the pressure-flow characteristic curve, and whether the current user pressure difference is abnormal is determined according to the size of the ventricular pressure difference.

[0068] Specifically, the control unit can monitor the pump flow of the ventricular assist device 100 in real time, and calculate the average pump flow in each first period. Then the first pressure difference corresponding to the current rotational speed is found from the target characteristic curve. The first pressure difference is compared with the pressure difference between the aortic pressure and the left ventricular pressure of the user in a normal state, and if the first pressure difference is significantly different from the pressure difference of the user in a normal state, i.e., if the first pressure difference is less than a first pressure threshold or greater than a second pressure threshold, it is considered that the current user blood pressure is abnormal. The user's blood pressure being abnormal can include the left ventricular pressure being too low or the aortic pressure being too high due to the rotational speed of the ventricular assist device 100 being too high, or the left ventricular pressure being too high or the aortic pressure being too low due to the rotational speed of the ventricular assist device 100 being too low.

[0069] The first pressure threshold is a difference between a lower limit value of the aortic pressure and an upper limit value of the left ventricular pressure of the user in normal state, and the second pressure threshold is a difference between an upper limit value of the aortic pressure and a lower limit value of the left ventricular pressure of the user in normal state. For example, the first pressure threshold is set to 35 mmHg, and the second pressure threshold is set to 80 mmHg. When the first pressure difference is less than 35 mmHg, it is considered that the blood pressure of the user is too low; and when the first pressure difference is less than 80 mmHg, it is considered that the blood pressure of the user is too high.

[0070] Further, when the abnormal blood pressure of the user is monitored, the control unit can autonomously adjust the rotation speed of the ventricular assist device 100 to solve the situation that the blood pressure of the user is abnormal due to the mismatch between the rotation speed of the ventricular assist device 100 and the current demand of the user.

[0071] The first pressure difference is less than the first pressure difference threshold, indicating that the rotation speed of the ventricular assist device 100 is too low to cause the left ventricular pressure to be too high or the aortic pressure to be too low, at this time, the blood volume in the left ventricle 128 is too much, and the rotation speed of the ventricular assist device 100 needs to be increased; or the first pressure difference is greater than the second pressure difference threshold, indicating that the current rotation speed of the ventricular assist device 100 is too high to cause the left ventricular pressure to be too low or the aortic pressure to be too high, at this time, the blood volume in the left ventricle 128 is too little, and the rotation speed of the ventricular assist device 100 needs to be increased. Therefore, when the first pressure difference is less than the first pressure difference threshold, the control unit controls the rotation speed of the ventricular assist device 100 to be increased by rotation speed steps Δv in turn until the first pressure difference is greater than the first pressure difference threshold and less than the second pressure difference threshold, or the number of times of increasing the rotation speed steps Δv exceeds n. Similarly, when the first pressure difference is greater than the second pressure difference threshold, the control unit controls the rotation speed of the ventricular assist device 100 to be decreased by rotation speed steps Δv in turn until the first pressure difference is greater than the first pressure difference threshold and less than the second pressure difference threshold, or the number of times of decreasing the rotation speed steps Δv exceeds n.

[0072] In the embodiments of the present application, the control unit can monitor the blood pressure of the user in real time without additional monitoring devices or apparatuses, and when the blood pressure of the user is abnormal, the rotation speed of the ventricular assist device 100 is autonomously adjusted to reduce or solve the problem of abnormal blood pressure of the user, which can reduce or avoid the harm caused by abnormal blood pressure and improve the safety of the user.

[0073] In a possible embodiment, after the ventricular assist device is started, the method further includes: obtaining a target efficiency mapping table and a third average flow rate, the target efficiency mapping table is a mapping table between the pressure difference and the rotation speed at which the efficiency of the ventricular assist device is optimal under the pressure difference, and the third average flow rate is an average pumping flow rate of the ventricular assist device within a third time length after the ventricular assist device is started; determining a second pressure difference corresponding to the third average flow rate according to the target characteristic curve; determining a target rotation speed corresponding to the second pressure difference according to the target efficiency mapping table; and adjusting the rotation speed of the ventricular assist device to the target rotation speed.

[0074] In practical applications, the starting rotation speed of the ventricular assist device 100 is set by the doctor according to experience and user conditions, and it may take multiple attempts and a long time to find the appropriate running speed, and the running speed cannot be automatically adjusted or can only be adjusted according to the set rotation speed adjustment interval and adjustment frequency. May make the auxiliary ventricular assist device 100 run in the low efficiency area for a long time, which cannot fully exert the advantages of the auxiliary ventricular assist device 100, and may have the risk of blood damage or increase the risk of thrombosis.

[0075] Based on this, after the ventricular assist device 100 is started, the control unit can directly adjust the rotation speed of the ventricular assist device 100 to the rotation speed with the best running efficiency, so as to improve the running efficiency of the ventricular assist device 100 while reducing the duration of the regurgitation of the ventricular assist device 100 and reducing the harm of the regurgitation to the user.

[0076] Among them, according to the pressure-flow characteristic curve of the ventricular assist device 100, at different rotation speeds, different pumping flows correspond to different ventricular pressure differences. The ventricular pressure difference is the pressure difference between the user's aortic pressure and the left ventricular pressure, which can also be represented as the pressure difference between the pressure at the outlet of the ventricular assist device 100 and the pressure at the inlet. Before the ventricular assist device 100 leaves the factory, it can be placed in a test system to test the pressure-flow characteristic curve of the ventricular assist device 100 at each rotation speed or rotation speed level, and mark the pressure difference at each rotation speed when the ventricular assist device 100 runs at the best efficiency, and then fit the best efficiency mapping table of the pressure difference and the rotation speed.

[0077] After the ventricular assist device 100 is started, the control unit can monitor the pumping flow of the ventricular assist device 100 in real time, and calculate the average pumping flow of the ventricular assist device 100 in the third time period. Then find the second pressure difference corresponding to the current rotation speed from the target characteristic curve, and then determine the rotation speed at which the ventricular assist device 100 runs at the best efficiency at the second pressure difference according to the target efficiency mapping table, and then directly adjust the rotation speed of the ventricular assist device 100 to the target rotation speed, which can reduce the workload of artificial monitoring and adjustment of medical staff, improve efficiency, and always keep the ventricular assist device 100 running in the best efficiency interval.

[0078] Among them, the rotation speed at which the ventricular assist device 100 runs at the best efficiency refers to the rotation speed at which the ventricular assist device 100 can provide the same pumping flow or more pumping flow with the least power consumption.

[0079] It should be noted that the target rotation speed can be any value within a rotation speed range. For example, if the target rotation speed is 35,000 RPM, then when the ventricular assist device 100 is adjusted to a rotation speed within the range of 35,000 RPM ± 1,000 RPM, it can be considered to reach the target rotation speed.

[0080] Further, when the corresponding second differential pressure is less than the low blood pressure alarm threshold or greater than the high blood pressure alarm threshold, i.e. when the second differential pressure is less than the first pressure threshold or greater than the second pressure threshold, the control unit can not control the ventricular assist device 100 to be adjusted to the target rotating speed.

[0081] In a possible embodiment, the method further comprises: obtaining a target heart rate, the target heart rate being a number of times of occurrence of the first pumping flow of the ventricular assist device within a preset time; and determining that a target user heart rhythm is abnormal and alarming if the target heart rate is less than a first heart rate threshold or greater than a second heart rate threshold.

[0082] In actual application, in addition to insufficient blood pumping of heart function, the heart failure of a user also has many complications, such as arrhythmia, ventricular fibrillation, bradycardia or tachycardia and other heart rhythm abnormality problems. Therefore, in the process of operation of the ventricular assist device 100, the control unit also needs to monitor the heart rhythm of the user in real time, so as to timely alarm and prompt the user to seek medical treatment as soon as possible for intervention, or prompt the doctor to diagnose and take necessary disposal measures as soon as possible, so as to reduce various risks brought by arrhythmia and improve the survival rate of the user.

[0083] The heart rate is the number of times of beating of the heart per minute. The length of the cardiac cycle is related to the heart rate, wherein the heart rate increases and the cardiac cycle shortens. In the process of operation of the ventricular assist device 100, the control unit monitors the pumping flow of the ventricular assist device 100 in real time, takes the time interval of adjacent first pumping flows as the cardiac cycle, and records the number of times of occurrence of the first pumping flow within 1 min (i.e. the target heart rate). Then the target heart rate is compared with a normal heart rhythm range, and if the target heart rate is less than a first heart rate threshold or greater than a second heart rate threshold, it is considered that the current heart rhythm is abnormal.

[0084] For example, the first heart rate threshold can be set to 40 times / min and the second heart rate threshold can be set to 150 times / min. When the target heart rate is less than 40 times / min, it is considered that the current target user is bradycardia, and the control unit can alarm to indicate that the user is currently bradycardia. When the target heart rate is less than 150 times / min, it is considered that the current target user is tachycardia, and the control unit can alarm to indicate that the user is currently tachycardia.

[0085] For example, the control unit can also set the priority of the alarm, grade the judgment threshold of bradycardia or tachycardia, and adopt different alarm levels. For example, a low-priority bradycardia prompt can be issued when the target heart rate is less than 60 times / min, a medium-priority bradycardia alarm can be issued when the target heart rate is less than 50 times / min, and a high-priority bradycardia alarm can be issued when the target heart rate is less than 40 times / min.

[0086] Optionally, the method further comprises: acquiring a fourth pumping flow in the first time length, the fourth pumping flow being a flow valley value pumped by the ventricular assist device; calculating a fourth average flow, the fourth average flow being an average value of the fourth pumping flow and the first pumping flow; calculating a target beat index according to the first pumping flow, the fourth pumping flow and the fourth average flow; and determining that the target user has an abnormal heart rhythm and alarming if the target beat is less than a beat threshold.

[0087] In the embodiments of the present application, the control unit can also monitor the current ventricular fibrillation of the user according to the fluctuation of the pumping flow of the ventricular assist device 100. Specifically, the control unit monitors the pumping flow of the ventricular assist device 100 in real time, records the flow peak value Lmax (the first pumping flow) pumped by the ventricular assist device 100 and the flow valley value Lmin (the fourth pumping flow) adjacent to the flow peak value pumped by the ventricular assist device 100, and calculates the average pumping flow Lave (the second average flow) between the flow peak value Lmax and the flow valley value Lmin. Then, the fluctuation index of the pumping flow of the ventricular assist device 100 is calculated, and the fluctuation index PI = (Lmax-Lmin) / Lave. Since the change of the pumping flow of the ventricular assist device 100 is synchronized with the cardiac cycle of the user, the beat index of the user can be represented by the fluctuation index of the pumping flow of the ventricular assist device 100. If the calculated target beat index PI is less than the beat threshold, it is determined that the target user currently has ventricular fibrillation, and the control unit can alarm the ventricular fibrillation.

[0088] Further, to reduce the risk of false alarm, the control unit can calculate the beat index PI in the first cycle, and if the beat index PI in the first cycle is continuously less than the beat threshold or 80% of the beat index PI in the first cycle is less than the beat threshold, it is determined that the target user currently has ventricular fibrillation and alarms the same.

[0089] Optionally, the method further comprises: calculating a target change coefficient, the target change coefficient being a ratio of adjacent first pumping flows or a ratio of adjacent first time lengths; and determining that the target user has an abnormal heart rhythm and alarming if the target change coefficient is less than a second value or greater than a third value.

[0090] In the embodiments of the present application, the control unit can also monitor whether the current user has arrhythmia according to the fluctuation of the pumping flow of the ventricular assist device 100. Specifically, the control unit monitors the pumping flow of the ventricular assist device 100 in the first cycle in real time, and records each first pumping flow in the first cycle and the time corresponding to the first pumping flow. Then, the change coefficient of the pumping flow in the first cycle is calculated, that is, the ratio of each adjacent first pumping flow (K i = Lmax i / Lmaxi-1 ), or a ratio of the interval duration between adjacent first pumping flows (K i = t i / t i-1 , t i is the interval duration between adjacent first pumping flows), to obtain a plurality of target variation coefficients. If the plurality of target variation coefficients in the first period are all less than a second value or greater than a third value, it is determined that the current target user has arrhythmia, and the control unit can alarm for arrhythmia.

[0091] The first value and the second value can be set according to the normal heart rate of the target user. For example, the second value can be set to 0.8, and the first value can be set to 1.2.

[0092] In the embodiments of the present application, the control unit can calculate abnormal flow fluctuation phenomenon according to the characteristic that the pump flow of the ventricular assist device 100 changes in accordance with the cardiac cycle, without other additional monitoring equipment or devices, to continuously monitor the heart rate of the patient in real time, and to determine the corresponding heart rhythm abnormality (such as tachycardia, ventricular fibrillation, premature beat, etc.) and issue an alarm, prompting the user to seek medical treatment as soon as possible for intervention, or prompting the doctor to diagnose as soon as possible and take necessary measures, to reduce the risks brought by arrhythmia and improve the survival rate of the user.

[0093] It can be seen that the present application proposes an adaptive control method, which obtains a plurality of pumping flows of the ventricular assist device when the ventricular assist device runs at a first rotating speed in a first period; records a first duration and a second duration, the first duration being the interval duration between adjacent first pumping flows, and the second duration being the duration of the first pumping flow to a pumping flow less than a first flow threshold in the first duration, the first pumping flow being the peak value of the pumping flow of the ventricular assist device; and adjusts the first rotating speed according to a target ratio, the target ratio being the ratio of the second duration to the first duration. According to the first duration and the second duration, the present application can respectively determine the cardiac cycle of the user and the low flow value of the ventricular assist device, and adjust the rotating speed of the ventricular assist device by the ratio of the second duration to the first duration, so that the pumping flow of the ventricular assist device can meet the needs of the user in real time, reduce the abnormality of the ventricular assist device, and improve the safety of the user.

[0094] The above describes the scheme of the embodiments of the present application mainly from the perspective of the method executing the process. It can be understood that, in order to implement the above functions, the network device comprises a hardware structure and / or a software module corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the unit and algorithm steps of each example described in the embodiments provided herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is implemented in hardware or computer software driven hardware depends on the specific application of the technical solution and the design constraint conditions. The skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0095] In an example, the present application provides a control device of a ventricular assist device, the control device comprising one or more processors configured to: obtain a plurality of pumping flows of the ventricular assist device when the ventricular assist device is operated at a first rotation speed in a first period; the first time length is a time length of adjacent first pumping flow intervals, the second time length is a time length of the first pumping flow to the pumping flow less than a first flow threshold in the first time length, the first pumping flow is a peak value of the pumping flow of the ventricular assist device; and adjust the first rotation speed according to a target ratio, the target ratio being a ratio of the second time length to the first time length.

[0096] In an example, the present application also provides a ventricular assist device, characterized in that the ventricular assist device comprises:

[0097] a housing;

[0098] an impeller arranged in the housing;

[0099] a control unit configured to control rotation of the impeller, the control unit being configured to perform some or all of the steps described in the above method.

[0100] In an example, the present application also provides a medical device comprising the above control device or ventricular assist device.

[0101] The control device of each of the above schemes has a function of implementing the corresponding steps performed by the medical device in the above method; the function can be implemented by hardware, or by hardware executing corresponding software.

[0102] In the embodiments of the present application, the control device can also be a chip or a chip system, for example, a system on chip (SoC).

[0103] Please refer to Figure 4 , Figure 4is a structural schematic diagram of a medical device provided by an embodiment of the present application, and the medical device comprises one or more processors, one or more memories, one or more communication interfaces, and one or more programs; the one or more programs are stored in the memory and are configured to be executed by the one or more processors.

[0104] The above program comprises instructions for performing the following steps:

[0105] obtaining a plurality of pumping flows of the ventricular assist device when the ventricular assist device operates at a first rotating speed in a first period;

[0106] The first duration is a duration of adjacent first pumping flow intervals, the second duration is a duration of the first pumping flow to the pumping flow less than a first flow threshold in the first duration, and the first pumping flow is a peak value of the pumping flow of the ventricular assist device;

[0107] adjusting the first rotating speed according to a target ratio, and the target ratio is a ratio of the second duration to the first duration.

[0108] All related contents of each scenario involved in the above method embodiments can be cited to the function description of the corresponding function module, and will not be repeated here.

[0109] It should be understood that the above memory can include read-only memory and random access memory, and provide instructions and data to the processor. A part of the memory can also include non-volatile random access memory. For example, the memory can also store device type information.

[0110] In the embodiments of the present application, the processor of the above device can be a central processing unit (CPU), and the processor can also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0111] It should be understood that “at least one” in the embodiments of the present application refers to one or more, and “multiple” refers to two or more. “And / or” describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. The character “ / ” generally represents an “or” relationship between the associated objects before and after it. “At least one of the following” or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0112] In addition, unless otherwise stated, the ordinal numbers mentioned in the embodiments of the present application are used to distinguish a plurality of objects, and are not used to limit the order, time sequence, priority or importance of the plurality of objects. For example, the first information and the second information are only used to distinguish different information, and do not mean that the contents, priorities, sending orders or importance of the two kinds of information are different.

[0113] In the implementation process, each step of the above method can be completed by integrated logic circuit of hardware in the processor or instruction in the form of software. The steps of the method disclosed in the embodiments of the present application can be directly embodied as hardware processor execution completion, or executed by hardware and software units in the processor. The software unit can be located in a mature storage medium in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, register, etc. The storage medium is located in the memory, and the processor executes the instructions in the memory, and combines the hardware to complete the steps of the above method. To avoid repetition, it will not be described in detail here.

[0114] The embodiments of the present application also provide a computer storage medium, wherein the computer storage medium stores a computer program for electronic data exchange, and the computer program enables a computer to execute part or all of the steps of any method described in the above method embodiments.

[0115] The embodiments of the present application also provide a computer program product, and the above computer program product includes a non-transitory computer readable storage medium storing a computer program, and the computer program is operable to enable a computer to execute part or all of the steps of any method described in the above method embodiments. The computer program product can be a software installation package.

[0116] It should be noted that, for the foregoing method embodiments, the sequences of the described actions can be modified, and certain actions can be performed simultaneously or in different sequences. In addition, the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0117] In the above embodiments, the description of each embodiment is focused on, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0118] In the several embodiments provided by the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only schematic. The division of the above units is only a logical function division. There can be another division during actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different parts can be indirect couplings or communication connections through some interfaces, devices or units, and can be electrical, or other forms.

[0119] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0120] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0121] If the above integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable memory. Based on this understanding, the technical solutions of the present application essentially or say the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a memory and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server or a TRP, etc.) to execute all or part of the steps of the embodiments of the present application. The aforementioned memory includes: a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0122] A person of ordinary skill in the art can understand that all or part of the steps in the above-mentioned embodiments can be completed by a program instructing relevant hardware, and the program can be stored in a computer readable memory, which can include a flash disk, a ROM, a RAM, a magnetic disk or an optical disk, etc.

[0123] The embodiments of the present application are described in detail above, and the principles and implementation manners of the present application are described by applying specific examples. The above description of the embodiments is only used to help understand the method of the present application and its core idea; meanwhile, for those of ordinary skill in the art, according to the idea of the present application, the specific implementation manner and application range will be changed, and the above description of the content of the specification should not be understood as a limitation of the present application.

Claims

1. A control unit for a ventricular assist device, characterized in that: The control unit includes one or more processors configured to perform the following steps: acquiring a plurality of pumping flow rates of the ventricular assist device when the ventricular assist device operates at a first rotational speed in a first cycle; Recording a first duration and a second duration, wherein the first duration is the duration of intervals between adjacent first pumping flow rates, and the second duration is the duration from the first pumping flow rate to the pumping flow rate less than a first flow rate threshold within the first duration, wherein the first pumping flow rate is the peak value of the pumping flow rate of the ventricular assist device; adjusting the first speed according to a target ratio, wherein the target ratio is a ratio of the second duration to the first duration; Wherein, adjusting the first speed according to the target ratio includes: If the target ratio is greater than a first target value, sequentially increasing the first speed until the first speed increases by n speed steps or the difference between a first average flow rate and a second average flow rate is greater than a second flow rate threshold, where the first average flow rate is an average of the pumping flow rate in the first period, the second average flow rate is an average of the pumping flow rate in the second period, the first period is earlier than the second period, and n is a positive integer; If the target ratio is less than the second target value, the first speed is reduced in sequence until the first speed is reduced by n speed steps or the difference between the second average flow rate and the first average flow rate is greater than the second flow rate threshold.

2. The control unit according to claim 1, characterized in that The control unit is further configured to perform the following steps: determining a second pumping flow rate and a target number, wherein the target number is the number of pumping flows less than the first flow rate threshold during the first time period, and the second pumping flow rate is the minimum pumping flow rate during the first time period; If the second pumping flow rate is less than a third flow rate threshold and the target number is greater than or equal to a first value, it is determined that reflux exists in the ventricular assist device and an alarm is issued.

3. The control unit according to claim 1, characterized in that The control unit is further configured to perform the following steps: Acquiring a target characteristic curve, where the target characteristic curve is a pressure-flow characteristic curve of the ventricular assist device; determining, based on the target characteristic curve, a first pressure differential corresponding to a first average flow rate at the first speed, the first pressure differential being a difference between a pressure at an outlet and a pressure at an inlet of the ventricular assist device; If the first pressure difference is less than a first pressure threshold, or the first pressure difference is greater than a second pressure threshold, it is determined that the blood pressure of the target user is abnormal and an alarm is issued. The target user is a user implanted with the ventricular assist device.

4. The control unit according to claim 1, characterized in that After the ventricular assist device is activated, the control unit is further configured to perform the following steps: obtaining a target efficiency mapping table and a third average flow rate, wherein the target efficiency mapping table is a mapping table between a pressure difference and a rotational speed at which the ventricular assist device has optimal operating efficiency under the pressure difference, and the third average flow rate is an average pumping flow rate of the ventricular assist device within a third period of time after activation; determining a second pressure difference corresponding to the third average flow rate according to a target characteristic curve; determining a target speed corresponding to the second pressure difference according to the target efficiency mapping table; The rotation speed of the ventricular assist device is adjusted to the target rotation speed.

5. The control unit according to claim 1, characterized in that The control unit is further configured to perform the following steps: Obtaining a target heart rate, where the target heart rate is the number of times the first pumping flow rate occurs within a preset time by the ventricular assist device; If the target heart rate is less than the first heart rate threshold or greater than the second heart rate threshold, it is determined that the target user has an abnormal heart rhythm and an alarm is issued.

6. The control unit according to claim 1, characterized in that The control unit is further configured to perform the following steps: acquiring a fourth pumping flow rate within the first time period, where the fourth pumping flow rate is a valley value of the pumping flow rate of the ventricular assist device; calculating a fourth average flow rate, where the fourth average flow rate is an average of the fourth pumping flow rate and the first pumping flow rate; calculating a target pulsatility index based on the first pumping flow rate, the fourth pumping flow rate, and the fourth average flow rate; If the target pulsation is less than the pulsation threshold, it is determined that the target user has an abnormal heart rhythm and an alarm is issued.

7. The control unit according to claim 1, characterized in that The control unit is further configured to perform the following steps: Calculating a target variation coefficient, where the target variation coefficient is a ratio of adjacent first pumping flow rates or a ratio of adjacent first time durations; If the target variation coefficient is less than the second value or greater than the third value, it is determined that the target user has an abnormal heart rhythm and an alarm is issued.

8. A ventricular assist device, characterized in that: The ventricular assist device comprises: case; an impeller disposed within the housing; A control unit for controlling the rotation of the impeller, wherein the control unit comprises one or more processors, and the one or more processors are configured to execute the steps as described in any one of claims 1 to 7.

9. A medical device, characterized in that: The system comprises a processor, a memory and a communication interface, wherein the memory stores one or more programs, and the one or more programs are executed by the processor, and the one or more programs include instructions for executing the steps according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program for electronic data exchange, wherein the computer program enables a computer to execute the steps according to any one of claims 1 to 7.

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