Abnormality detection method and device for ventricular assist device

Abstract

The invention provides an anomaly detection method and device for a ventricular assist device.The method comprises the steps that first pumping flow and second pumping flow are obtained, the first pumping flow is the maximum pumping flow of the ventricular assist device in a first period when the ventricular assist device operates at a target rotating speed, and the second pumping flow is the maximum pumping flow of the ventricular assist device in a second period; the second pumping flow is the minimum pumping flow in the first period when the ventricular assist device operates at the target rotating speed; a target value is calculated, the target value is the specific value of the target flow difference and the first average flow, and the target flow difference is the difference value of the first pumping flow and the second pumping flow; and judging whether the ventricular assist device is abnormal or not according to the first pumping flow, the second pumping flow and the target value. The operation condition of the ventricular assist device is monitored in real time according to the assist and fluctuation condition of the pumping flow of the ventricular assist device in the cardiac cycle, the accuracy of abnormal operation detection of the ventricular assist device is improved, and therefore the pumping efficiency of the ventricular assist device is improved.

Description

Technical Field

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

[0002] Percutaneous circulatory support devices or blood pumps can provide short-term support for up to several weeks for patients with impaired cardiac function or cardiac output. Some of these devices, especially ventricular assist devices, currently operate at a set constant speed. However, due to different output requirements of users in different states, the pumping flow of the ventricular assist device may not match the user's current condition requirements. The abnormalities caused by this mismatch will reduce the performance of the ventricular assist device, and in severe cases, may even damage the patient's heart. Therefore, how to monitor the abnormalities of the ventricular assist device in real time during its operation is urgently needed. Summary of the invention

[0003] The embodiments of the present application provide a method and device for detecting abnormalities in a ventricular assist device, which can monitor in real time whether the ventricular assist device is operating abnormally based on the pumping flow of the ventricular assist device, thereby improving the pumping efficiency of the ventricular assist device.

[0004] In a first aspect, an embodiment of the present application provides a method for detecting abnormality of a ventricular assist device, the method comprising:

[0005] Acquire a first pumping flow rate and a second pumping flow rate, wherein the first pumping flow rate is a maximum pumping flow rate in a first cycle when the ventricular assist device operates at a target speed, and the second pumping flow rate is a minimum pumping flow rate in the first cycle when the ventricular assist device operates at the target speed, and the first cycle is a time interval between adjacent first pumping flows or second pumping flows;

[0006] Calculating a target value, wherein the target value is a ratio of a target flow difference to a first average flow, wherein the target flow difference is a difference between the first pumping flow and the second pumping flow, and the first average flow is an average pumping flow of the ventricular assist device in the first cycle;

[0007] Whether the ventricular assist device is abnormal is determined based on the first pumping flow rate, the second pumping flow rate, and the target value.

[0008] In a second aspect, an embodiment of the present application provides a control unit of a ventricular assist device, the control unit comprising one or more processors, the one or more processors being used to:

[0009] Acquire a first pumping flow rate and a second pumping flow rate, wherein the first pumping flow rate is a maximum pumping flow rate in a first cycle when the ventricular assist device operates at a target speed, and the second pumping flow rate is a minimum pumping flow rate in the first cycle when the ventricular assist device operates at the target speed, and the first cycle is a time interval between adjacent first pumping flows or second pumping flows;

[0010] Calculating a target value, wherein the target value is a ratio of a target flow difference to a first average flow, wherein the target flow difference is a difference between the first pumping flow and the second pumping flow, and the first average flow is an average pumping flow of the ventricular assist device in the first cycle;

[0011] Whether the ventricular assist device is abnormal is determined based on the first pumping flow rate, the second pumping flow rate, and the target value.

[0012] In a third aspect, an embodiment of the present application provides a ventricular assist device, the ventricular assist device comprising:

[0013] case;

[0014] an impeller disposed in the housing;

[0015] A control unit for controlling the rotation of the impeller, wherein the control unit is used to execute the steps in the method described in the first aspect above.

[0016] In a fourth aspect, an embodiment of the present application provides a medical device, comprising a processor, a memory, a communication interface, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and the program includes instructions for executing some or all of the steps described in the method described in the first aspect above.

[0017] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program for electronic data exchange, wherein the computer program enables a computer to execute some or all of the steps described in the method described in the first aspect above.

[0018] In a sixth aspect, an embodiment of the present application provides a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute some or all of the steps described in the method described in the first aspect of the embodiment of the present application. The computer program product may be a software installation package.

[0019] The technical solution provided by the present application is to obtain a first pumping flow rate and a second pumping flow rate, wherein the first pumping flow rate is the maximum pumping flow rate of the ventricular assist device in the first cycle when the ventricular assist device is running at a target speed, and the second pumping flow rate is the minimum pumping flow rate of the ventricular assist device in the first cycle when the ventricular assist device is running at a target speed, and the first cycle is the interval between adjacent first pumping flows or second pumping flows; calculate a target value, wherein the target value is the ratio of a target flow difference to a first average flow rate, the target flow difference is the difference between the first pumping flow rate and the second pumping flow rate, and the first average flow rate is the average pumping flow rate of the ventricular assist device in the first cycle; and determine whether the ventricular assist device is abnormal based on the first pumping flow rate, the second pumping flow rate and the target value. The present application monitors the operation of the ventricular assist device in real time through the assistance and fluctuation of the pumping flow rate of the ventricular assist device in the cardiac cycle, thereby improving the accuracy of detecting abnormal operation of the ventricular assist device and thus improving the pumping efficiency of the ventricular assist device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a schematic structural diagram of a ventricular assist device provided in an embodiment of the present application;

[0022] Figure 2 is a schematic diagram of a ventricular assist device provided by an embodiment of the present application located in a normal position of a patient's heart;

[0023] Figure 3 It is a flowchart of a method for detecting abnormality of a ventricular assist device provided in an embodiment of the present application;

[0024] Figure 4 is a schematic diagram of a pumping flow rate of a ventricular assist device provided in an embodiment of the present application;

[0025] Figure 5 It is a structural schematic diagram of a medical device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to help those skilled in the art better understand the technical solutions of the present application, the following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the description of the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0027] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, software, product, or device that includes a series of steps or units is not limited to the listed steps or units, but also includes steps or units that are not listed, or also includes other steps or units inherent to these processes, methods, products, or devices.

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

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

[0030] "Current" in this application refers to the current driving the motor or motor, which is related to the power of the motor or motor when the supply voltage remains unchanged. "Speed" refers to the rotational speed of the motor or motor, which is related to the rotational speed of the rotor or 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 delivered by the ventricular assist device per time unit, which can be estimated and measured in liters per minute.

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

[0032] See also Figure 1-Figure 2 , Figure 1is a schematic structural diagram of a ventricular assist device 100 provided in an embodiment of the present application. Figure 2 1 is a schematic diagram of a ventricular assist device 100 provided in an embodiment of the present application, which is located in a normal position of a user's heart 120. The ventricular assist device 100 can be placed in the user's left heart, right heart, outside the heart, partially outside the heart, partially outside the vascular system, or in any other suitable position in the vascular system. For example, the present application takes the ventricular assist device 100 placed in the left heart as an example for description.

[0033] For example, the ventricular assist device 100 is used for protection in high-risk percutaneous coronary intervention (HR-PCI) surgery, maintaining hemodynamic stability of high-risk patients before intervention to prevent severe hypotension / low cardiac output (CO), and to gain enough time to achieve optimal and complete revascularization. The ventricular assist device 100 can be percutaneously inserted into the aorta 124 through the femoral artery 122, and pass through the aorta 124 into the left ventricle 128. For example, the ventricular assist device 100 can be percutaneously inserted into the aorta 124 through the axillary artery 123, and pass through the aorta 124 into the left ventricle. In other embodiments, the ventricular assist device 100 can also be directly inserted into the aorta 124, and pass through the aortic valve 126 into the left ventricle 128. During operation, the ventricular assist device 100 pumps blood in the left ventricle 128 into the aorta 124, thereby achieving an auxiliary pumping function for the heart.

[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 has a fluid inlet 101, and the proximal end of the cannula 10 has a fluid outlet 102. Blood flows in from the fluid inlet 101 and flows out from 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, so that when the ventricular assist device 100 is in operation, the impeller is driven to rotate to pump blood from the left ventricle 128 to the aorta 124.

[0036] The ventricular assist device 100 may include a motor (not shown in the figure), which may be disposed inside the ventricular assist device 100 or outside the ventricular assist device 100. The present application embodiment takes the case where the motor is disposed inside the ventricular assist device 100 as an example for explanation, for example, the motor is disposed in the motor housing 201, the distal end of the motor housing 201 is connected to the proximal end of the cannula 10, and the motor drives the drive shaft to rotate, thereby driving the impeller to rotate, thereby realizing the blood pumping function of the ventricular assist device 100.

[0037] The ventricular assist device 100 includes a catheter 30, the distal end of which is 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 an electrical wire connecting the ventricular assist device 100 to an external controller. For example, the ventricular assist device 100 also includes a distal component 110 extending distally from the distal end of the cannula 10, such as a pigtail tube.

[0038] The ventricular assist device 100 also includes a control unit, which can be used to execute any embodiment, aspect and method in the present application. The control unit can be arranged inside the ventricular assist device 100, or it can be arranged outside the ventricular assist device 100. The control unit is used to detect relevant parameters of the ventricular assist device 100 and the user, and to 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 (such as a phase current detection circuit); estimates the current pumping flow rate based on the received current, and controls the rotation speed of the ventricular assist device 100 according to the received instructions; and then detects whether there are abnormal events such as suction and reflux based on the pump speed flow rate and rotation speed, and so on.

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

[0040] For example, the ventricular assist device 100 may also include a plurality of pressure sensors, which may be disposed on the outer surface of the fluid inlet 101 and / or the outer surface of the fluid outlet of the ventricular assist device 100 for measuring the patient's left ventricular pressure and / or aortic pressure in real time.

[0041] During the operation of the ventricular assist device 100, due to the fluidity of the blood, the change trend of the pumping flow of the ventricular assist device 100 needs to be synchronized with the patient's cardiac cycle to avoid problems such as suction and collapse. For example, when the blood flowing into the heart is reduced, the blood may be pumped out of the ventricle by the ventricular assist device 100 at a rate faster than the ventricular filling rate, which usually affects the internal and external pressure difference of the left ventricle 128. The long-term pressure difference will cause the left ventricular pressure to be lower than the aortic pressure, and even cause a suction event in the ventricle in severe cases. In addition, the rapid pumping of blood in the left ventricle 128 will cause the ventricular pressure to fail to reach a sufficient level to open the aortic valve leaflets, causing the heart to lose pulsation during systole, causing aortic valve 126 regurgitation, that is, it cannot be completely closed during diastole, causing blood to flow back from the aorta 124 to the left ventricle 128, causing thrombosis in the right atrium, causing pulmonary hypertension, leading to pulmonary embolism, and even aggravating heart failure in severe cases.

[0042] Based on this, the present application proposes a method for detecting abnormalities in a ventricular assist device, which obtains the pumping flow of the ventricular assist device 100, and determines whether there is an abnormality in the current ventricular assist device 100 through the changing trend and magnitude of the pumping flow, thereby improving the accuracy of abnormality detection.

[0043] In combination with the above description, the present application is described below from the perspective of method examples.

[0044] See also Figure 3 , Figure 3 A schematic flow chart of a method for detecting abnormality of a ventricular assist device provided in an embodiment of the present application is applied to Figure 1 The ventricular assist device shown. Figure 3 As shown, the method includes the following steps.

[0045] S310. Obtain a first pumping flow and a second pumping flow, wherein the first pumping flow is the maximum pumping flow within a first cycle when the ventricular assist device operates at a target speed, and the second pumping flow is the minimum pumping flow within the first cycle when the ventricular assist device operates at the target speed, and the first cycle is the time interval between adjacent first pumping flows or second pumping flows.

[0046] Among them, during the operation of the ventricular assist device 100 in the user's body, the pumping flow through the ventricular assist device 100 depends on the work that the ventricular assist device 100 needs to overcome resistance to pump blood from the left ventricle 128 to the aorta 124. The amount of work done by the ventricular assist device 100 can be quantified as the amount of current 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 is running in the user. During different stages 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 entering the aorta 124 increases (such as during cardiac contraction), the current required by the motor will increase. Therefore, the change in the motor current can help characterize the performance of the heart. 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 more work the ventricular assist device 100 does, that is, the greater the pumping flow of the ventricular assist device 100.

[0047] 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 leaves the factory, it can be placed in a test system to test the relationship curve between the pumping flow rate and the current change of the ventricular assist device 100 at different speeds, and then the current-flow characteristic curve is stored in the control unit. The control unit can store the detected current in real time.

[0048] When the ventricular assist device 100 is running at the first speed, after the control unit obtains the current curve in the first cycle, it estimates the flow curve corresponding to the current curve using the pre-stored current-flow characteristic curve, and the multiple pumping flows can be pumping flows collected from the flow curve at a sampling frequency. The first cycle can be the patient's cardiac cycle, and the control unit can determine the interval time between the valley or peak values ​​of adjacent pumping flows in the flow curve as the patient's cardiac cycle, and then determine whether there is an abnormality in the ventricular assist device 100 pumping flow according to the change trend of the pumping flow in one cardiac cycle, that is, whether its pumping flow matches the user's needs.

[0049] Specifically, after the ventricular assist device 100 is running, the control unit collects multiple pumping flows according to the sampling frequency, takes the time interval between the valley values ​​or peak values ​​of each two adjacent pumping flows in the multiple pumping flows as the first cycle, and then obtains the first pumping flow and the second pumping flow in each first cycle respectively. The abnormality of the ventricular assist device 100 is monitored in real time according to the first pumping flow and the second pumping flow.

[0050] S320. Calculate a target value, wherein the target value is a ratio of a target flow difference to a first average flow, wherein the target flow difference is a difference between the first pumping flow and the second pumping flow, and the first average flow is an average pumping flow of the ventricular assist device in the first cycle.

[0051] In the present application, the control unit can calculate the fluctuation of the pumping flow in each first cycle, and then determine whether the fluctuation matches the expected fluctuation of the pumping flow. The control unit calculates the difference between the first pumping flow and the second pumping flow, and the average value of the pumping flow in the first cycle. The fluctuation index of the pumping flow of the ventricular assist device 100 can be determined by calculating the ratio of the target flow difference to the first average flow. In this way, it can be determined whether the current ventricular assist device 100 has an abnormality.

[0052] S330. Determine whether the ventricular assist device is abnormal based on the first pumping flow rate, the second pumping flow rate and the target value.

[0053] When the ventricular assist device 100 is operated at a constant speed, the ideal pumping flow rate of the ventricular assist device 100 is as follows: Figure 4 As shown, it is synchronized with the patient's cardiac cycle. At the beginning of the cardiac cycle, the pumping flow of the ventricular assist device 100 is relatively low due to the relatively large difference between the aortic pressure and the left ventricular pressure. During the initial part of the ventricular contraction, the increase in left ventricular pressure reduces the difference between the aortic pressure and the left ventricular pressure, resulting in a corresponding increase in the pumping flow due to the decrease in the pressure difference across the ventricular assist device 100. During the ejection of blood from the left ventricle 108 to the aorta 124, the pumping flow gradually decreases as the aortic pressure gradually increases relative to the left ventricular pressure. After closing the native aortic valve 126, the pumping flow decreases significantly in response to the increase in the pressure difference across the ventricular assist device 100 due to the decrease in left ventricular pressure. After the mitral valve opens, the pumping flow gradually increases in response to the gradual decrease in the pressure difference across the ventricular assist device 100 caused primarily by the gradual decrease in aortic pressure.

[0054] Based on this, when the ventricular assist device 100 operates at a constant speed, the amplitude and change trend of its pumping flow are within a certain range. Therefore, when the ventricular assist device 100 operates abnormally, the pumping flow of the ventricular assist device 100 will also be abnormal. The control unit can determine whether the current ventricular assist device 100 operates abnormally based on the first pumping flow, the second pumping flow and the target value.

[0055] Optionally, judging whether the ventricular assist device is abnormal based on the first pumping flow, the second pumping flow and the target value includes: if the first pumping flow is greater than or equal to a first preset flow, and the second pumping flow is greater than or equal to a second preset flow, determining that the ventricular assist device is operating abnormally and causing aortic valve regurgitation; if the target value is less than the first value, determining that the aortic valve has moderate regurgitation; if the target value is less than the second value, determining that the aortic valve has severe regurgitation, and the second value is less than the first value.

[0056] The ventricular assist device 100 is inserted into the aorta 124 and passes through the aortic valve 126 into the left ventricle 128, so that its fluid inlet 101 is in the left ventricle 128 and the fluid outlet 102 is in the aorta 124, thereby pumping blood from the left ventricle 128 to the aorta 1241. However, the use of the ventricular assist device 100 may cause aortic valve 126 insufficiency, that is, the aortic valve 126 cannot properly seal and isolate the left ventricle 128 and the aorta 124 during diastole. For a fully implanted or long-term used ventricular assist device 100, aortic valve 126 insufficiency may be due to abnormal operation of the ventricular assist device 100, so that the left ventricular pressure does not reach a sufficient level to open the aortic valve leaflets, causing the heart to lose its pulsation during systole.

[0057] Regurgitation occurs at the aortic valve 126. During the period when the aortic valve 126 is open, the pumping flow of the ventricular assist device 100 is not affected. During the period when the aortic valve 126 is closed, such as during diastole, the aorta 124 and the left ventricle 128 are always in a connected state due to the incomplete closure or non-closure of the active valve 126. The left ventricular pressure will not be on a downward trend, and the pressure difference between the aortic pressure and the left ventricle will approach 0, resulting in regurgitation during diastole, and blood will flow back to the left ventricle through the incompletely closed aortic valve 126.

[0058] The control unit calculates the target value in each first cycle in real time, compares the target value, the first pumping flow rate and the second pumping flow rate with the preset value, and determines whether there is aortic valve 126 regurgitation based on the comparison result.

[0059] In an example, the method further includes: acquiring a target characteristic curve, the target characteristic curve being a pressure-flow characteristic curve when the ventricular assist device is running at a target speed; determining the first preset flow rate according to the target characteristic curve, the first preset flow rate being a pumping flow rate of the ventricular assist device at a preset pressure difference;

[0060] To determine whether the pumping flow rate of the ventricular assist device 100 is abnormal, the control unit may obtain a first preset flow rate to be compared with the first pumping flow rate. Figure 4 As shown, when the aortic valve 126 is closed during the contraction phase of the cardiac cycle (i.e., the aortic pressure is equal to the left ventricular pressure), the pumping flow of the ventricular assist device 100 reaches a maximum value. In other words, the pumping flow of the ventricular assist device 100 reaches a maximum value near the pressure difference between its two ends is 0. Based on this, the control unit can use the pumping flow corresponding to the pressure difference between the two ends of the ventricular assist device 100 is 0 as the first preset flow. When the maximum pumping flow of the ventricular assist device 100 is greater than the pumping flow corresponding to the pressure difference of 0, it indicates that the blood volume in the left ventricle 128 may be increased due to the regurgitation of the aortic valve 126, thereby possibly increasing the pumping flow of the ventricular assist device 100 during the contraction period.

[0061] In the present application, before the ventricular assist device 100 leaves the factory, the ventricular assist device 100 can be placed in a test environment to measure the characteristic curves of its pumping flow and ventricular pressure difference at different rotation speeds. The pressure-flow characteristic curve for each rotation speed is then stored in the control unit. When the ventricular assist device 100 is running, the target characteristic curve at the current rotation speed of the ventricular assist device 100 is obtained, and then the pumping flow corresponding to the pressure difference of 0 in the target characteristic curve is determined as the first preset flow. Since the aortic valve is not fully closed, there is always blood in the left ventricle, thereby increasing the minimum pumping flow in the ventricular assist device, so the second preset flow can be set to 0, 0.1L / min, 0.2L / min, 0.3L / min, or other values ​​close to 0.

[0062] Specifically, the control unit compares the first pumping flow rate with the first preset flow rate, and compares the second pumping flow rate with the second preset flow rate. If the first pumping flow rate is greater than or equal to the first preset flow rate, and the second pumping flow rate is greater than or equal to the second preset flow rate, it is determined that the aortic valve 126 has regurgitation due to abnormal operation of the ventricular assist device 100. When the aortic valve 126 has regurgitation, the fluctuation index of the pumping flow rate of the ventricular assist device 100 will be smaller than the fluctuation index of the pumping flow rate of the ventricular assist device 100 under normal circumstances. Therefore, when it is determined that the aortic valve 126 has regurgitation, the degree of regurgitation of the aortic valve 126 can be determined based on the fluctuation index of the pumping flow rate. Specifically: if the target value is less than the first value, it means that the current aortic valve 126 has moderate regurgitation; if the target value is less than the second value, it means that the current aortic valve 126 has severe regurgitation.

[0063] Furthermore, the control unit can alarm and display the regurgitation of the aortic valve 126, and provide corresponding suggestions according to the degree of regurgitation. For example, if the aortic valve 126 has moderate regurgitation, it can be recommended to increase the rotation speed of the ventricular assist device 100 to increase the left ventricular pressure; if the aortic valve 126 has severe regurgitation, it can be recommended to remove the pump to solve the regurgitation problem of the aortic valve 126 first.

[0064] The first value and the second value can be set according to clinical trials. For example, the first value is set to 0.5 and the second value is set to 0.2.

[0065] For example, the method further includes: determining a target pressure difference corresponding to the first average flow rate based on the target characteristic curve; if within a second cycle, the target pressure difference continues to be equal to the preset pressure difference, and the target value continues to be greater than or equal to the second preset flow rate, then it is determined that the position of the ventricular assist device is abnormal, and the second cycle is greater than the first cycle.

[0066] The relative position of the heart where the ventricular assist device 100 is located during operation determines whether the interventional ventricular assist device can assist the patient in achieving the pumping function. The ventricular assist device 100 is implanted into the patient's heart through a guidewire and is located in the desired position, that is, the proximal end of the cannula 10 is located in the patient's aorta 124, and the distal end is located in the patient's left ventricle 128. After the operation, the patient still needs the ventricular assist device 100 to assist and support for a period of time. During this time, the position of the ventricular assist device 100 in the patient cannot be detected in time and in real time, and the movement of the patient may cause the ventricular assist device 100 to shift, affecting the patient's life safety. Therefore, during the operation of the ventricular assist device 100, the present application can also monitor the position of the ventricular assist device 100 in the patient's body in real time, so as to be able to detect the abnormal position of the ventricular assist device 100 as early as possible and issue an alarm prompt, so as to improve intervention, reduce risk events, and improve patient life safety.

[0067] When the position of the ventricular assist device 100 is abnormal, that is, the fluid inlet 101 and the fluid outlet 102 are both in the aorta 124 or the left ventricle 128, the pressure difference between the fluid outlet 102 and the fluid inlet 101 is close to 0, and because the ventricular assist device 1001 cannot pump blood, the average pumping flow of the ventricular assist device 100 is also close to the corresponding pumping flow when the pressure difference on the pressure-flow characteristic curve is 0 at the current speed. At the same time, due to the synchronous change of the pressure at the fluid outlet 102 and the fluid inlet 101, the pressure difference does not change, so the flow fluctuation is close to 0. When the above pressure difference and flow conditions are simultaneously met, it can be determined that the current position of the ventricular assist device 100 is abnormal.

[0068] Specifically, the second cycle is the duration of multiple cardiac cycles. In multiple cardiac cycles, the average pumping flow in each cardiac cycle is calculated respectively, and then the target pressure difference corresponding to the average pumping flow is determined according to the target characteristic curve, and the target value in each cardiac cycle is calculated. If the target pressure difference is continuously equal to or close to 0 during the multiple cardiac cycles, and the standard value is continuously greater than or equal to 0 or close to 0, it is determined that the current position of the ventricular assist device 100 in the patient's body is abnormal, and an alarm is issued when the position is abnormal to ensure the patient's life safety.

[0069] In a possible example, the method further includes: obtaining the second pumping flow rate within n first cycles, where n is a positive integer; if the n second pumping flow rates are all less than the second preset flow rate, it is determined that reflux exists in the ventricular assist device, and an alarm is issued.

[0070] When the rotation speed of the ventricular assist device 100 is too low and the aortic pressure is higher than the left ventricular pressure, the blood pumped to the aorta 124 may flow back to the left ventricle 128 through the ventricular assist device 100, that is, the blood flows back from the fluid outlet 102 to the fluid inlet 101 through the ventricular assist device 100, thereby causing the blood pumped to the aorta 1241 to flow back to the left ventricle 128, resulting in insufficient blood supply while also increasing the load on the left ventricle 128.

[0071] During the operation of the ventricular assist device 100, the control unit can also monitor in real time whether there is a reflux phenomenon in the ventricular assist device 100. Specifically, the control unit obtains the minimum pumping flow rate (i.e., the second pumping flow rate) in each cardiac cycle from n cardiac cycles, and n can be 10, 20, 30, etc. If the second pumping flow rates in the n cardiac cycles are all less than 0, it can be determined that there is a reflux phenomenon in the current ventricular assist device 100. Then, an alarm is issued when reflux exists, and the current rotation speed and pumping flow rate are displayed and stored as the reflux alarm threshold.

[0072] In the embodiment of the present application, the control unit monitors in real time whether there is a reflux problem in the ventricular assist device 100, and then issues an alarm when a reflux problem exists. This can detect and reduce the reflux in the ventricular assist device 100 early, thereby improving the pumping efficiency of the ventricular assist device 100.

[0073] In a possible example, the method also includes: obtaining a first flow threshold and a second flow threshold; adjusting the target speed to adjust the first flow threshold and the second flow threshold; if the first flow threshold and the second flow threshold are both equal to the second pumping flow, determining that the ventricular assist device can be pumped out.

[0074] The interventional ventricular assist device 100 is used as a circulatory assist means during and after PCI surgery, which can reduce surgical risks and improve prognosis. After implantation of the interventional ventricular assist device 100, cardiac function will be improved or even restored, and the pump can be removed. In this application, when the pump needs to be removed, the control unit can perform a pump removal evaluation on the ventricular assist device 100 to accurately assess whether the patient can be removed from the ventricular assist device 100.

[0075] Whether the patient can be separated from the ventricular assist device 100 mainly depends on whether the patient's heart pumping capacity can support the patient's needs. Therefore, it is necessary to accurately simulate the patient's own pumping capacity after the ventricular assist device 100 is removed. In other words, when the pumping flow of the ventricular assist device 100 is close to 0, the patient's own pumping flow can meet the user's needs, that is, the pumping flow demand of the ventricular assist device 100 gradually approaches 0. Therefore, after receiving the pump withdrawal instruction, the control unit can obtain the first flow threshold and the second flow threshold. The rotation speed of the ventricular assist device 100 is continuously reduced or increased according to the first flow threshold and the second flow threshold, so that the pumping flow of the ventricular assist device 100 tends to be stable and the average pumping flow tends to be close to 0.

[0076] Among them, adjusting the target speed to adjust the first flow threshold and the second flow threshold includes: collecting the i-th pumping flow and the i+1-th pumping flow when the ventricular assist device is running at the target speed, wherein i is a positive integer; if the i-th pumping flow is greater than the i+1-th pumping flow, and the i+1-th pumping flow is greater than the first flow threshold, reducing the target speed at a first acceleration and reducing the first flow threshold; if the i-th pumping flow is less than the i+1-th pumping flow, and the i+1-th pumping flow is less than the second flow threshold, increasing the target speed at a second acceleration and increasing the second flow threshold; setting i=i+1, and repeating the above steps until the first duration is reached, or the target speed exceeds the preset speed range.

[0077] Specifically, the control unit collects multiple pumping flows from the flow curve according to the sampling frequency, and then compares two adjacent pumping flows. If the i-th pumping flow is greater than the i+1-th pumping flow and both are greater than the first flow threshold, the current rotation speed can be reduced to reduce the peak value of the pumping flow of the ventricular assist device 100 and reduce the first flow threshold; if the i-th pumping flow is less than the i+1-th pumping flow and both are less than the first flow threshold, the current rotation speed can be increased to increase the valley value of the pumping flow of the ventricular assist device 100 and increase the second flow threshold. This cycle is repeated until the first duration is reached or the rotation speed of the ventricular assist device 100 exceeds the preset allowable rotation speed range. After the cycle ends, if the average value of the first flow threshold and the second flow threshold is equal to 0 or close to 0, it means that the average pumping flow of the ventricular assist device 100 is close to 0, and the reflux effect in the ventricular assist device 100 is also small. At this time, the patient's own pumping capacity can meet his needs and the pump withdrawal condition can be met. If after the cycle ends, if the average value of the first flow threshold and the second flow threshold is greater than 1, it means that the current situation is not sufficient to meet the pump-off condition and the pump-off operation cannot be performed.

[0078] Wherein, the first flow threshold value can be reduced by a fixed value or a variable value each time. For example, the fixed value can be set to 0.1L / min, 0.3L / min, 0.5L / min, etc. For example, the control unit can calculate the average pumping flow rate in the cardiac cycle to which the i-th pumping flow rate belongs, and then reduce the first flow threshold value by 1 / 2, 1 / 3, 1 / 4, 1 / 5, etc. of the average pumping flow rate each time. For example, the control unit can also pre-store the mapping relationship between the current rotation speed and the reduced first flow threshold value according to clinical experimental data, and the larger the target rotation speed, the larger the reduced first flow threshold value.

[0079] Similarly, the first flow threshold value can be increased by a fixed value or a variable value each time. For example, the fixed value can be set to 0.1L / min, 0.3L / min, 0.5L / min, etc. For example, the control unit can calculate the average pumping flow rate in the cardiac cycle to which the i-th pumping flow rate belongs, and then each time the increase in flow threshold value is reduced by 1 / 2, 1 / 3, 1 / 4, 1 / 5, etc. of the average pumping flow rate. For example, the control unit can also pre-store the mapping relationship between the current rotation speed and the increased first flow threshold value based on clinical experimental data. The larger the target rotation speed, the larger the increased second flow threshold value.

[0080] For example, the first acceleration is less than 0, the second acceleration is greater than 0, and the first duration can be 12h, 24h, 36h, 72h, etc. The preset speed range can be set to 23000RPM to 46000RPM. For example, the control unit can use the slope of the i-th pumping flow rate and the i+1-th pumping flow rate as the first acceleration or the second acceleration.

[0081] In the embodiment of the present application, the control unit can accurately simulate the patient's own state after the ventricular assist device 100 is withdrawn by continuously increasing and decreasing the rotation speed of the ventricular assist device 100 so that the average pumping flow of the ventricular assist device 100 approaches 0, and accurately evaluate whether the patient can be separated from the ventricular assist device 100. The patient is accurately evaluated for pump withdrawal to reduce the safety of pump withdrawal and the incidence of adverse events after pump withdrawal.

[0082] It should be noted that when i=1, the first flow rate threshold and the second flow rate threshold may be the default first flow rate threshold and the second flow rate threshold pre-set by the user. For example, the default first flow rate threshold and the second flow rate threshold may be set to 4.0 L / min and -1.0 L / min, respectively.

[0083] It can be seen that the present application proposes a method for detecting abnormalities of a ventricular assist device, obtaining a first pumping flow and a second pumping flow, wherein the first pumping flow is the maximum pumping flow of the ventricular assist device in the first cycle when the ventricular assist device is running at a target speed, and the second pumping flow is the minimum pumping flow of the ventricular assist device in the first cycle when the ventricular assist device is running at a target speed, and the first cycle is the interval between adjacent first pumping flows or second pumping flows; calculating a target value, wherein the target value is the ratio of a target flow difference to a first average flow, wherein the target flow difference is the difference between the first pumping flow and the second pumping flow, and the first average flow is the average pumping flow of the ventricular assist device in the first cycle; and judging whether the ventricular assist device is abnormal based on the first pumping flow, the second pumping flow and the target value. The present application monitors the operation of the ventricular assist device in real time through the assistance and fluctuation of the pumping flow of the ventricular assist device in the cardiac cycle, thereby improving the accuracy of detecting abnormalities in the operation of the ventricular assist device and thus improving the pumping efficiency of the ventricular assist device.

[0084] The above mainly introduces the scheme of the embodiment of the present application from the perspective of the execution process on the method side. It is understandable that in order to realize the above functions, the network device includes a hardware structure and / or software module corresponding to each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiment provided in this article, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0085] As an example, the present application provides a control unit for a ventricular assist device, the control unit comprising one or more processors, the one or more processors being used to: obtain a first pumping flow and a second pumping flow, the first pumping flow being the maximum pumping flow of the ventricular assist device within a first cycle when the ventricular assist device operates at a target speed, the second pumping flow being the minimum pumping flow of the ventricular assist device within the first cycle when the ventricular assist device operates at the target speed, the first cycle being the time interval between adjacent first pumping flows or second pumping flows; calculate a target value, the target value being the ratio of a target flow difference to a first average flow, the target flow difference being the difference between the first pumping flow and the second pumping flow, the first average flow being the average pumping flow of the ventricular assist device within the first cycle; and determine whether the ventricular assist device is abnormal based on the first pumping flow, the second pumping flow and the target value.

[0086] For example, the present application also provides a ventricular assist device, characterized in that the ventricular assist device comprises:

[0087] case;

[0088] an impeller disposed in the housing;

[0089] A control unit for controlling the rotation of the impeller, wherein the control unit is used for part or all of the steps described in the above method.

[0090] As an example, the present application also provides a medical device, which includes the control device or ventricular assist device described above.

[0091] Among them, the control device of each of the above schemes has the function of implementing the corresponding steps performed by the medical equipment in the above method; the functions can be implemented by hardware, or by hardware executing corresponding software.

[0092] In the embodiments of the present application, the control device may also be a chip or a chip system, such as a system on chip (SoC).

[0093] See also Figure 5 , Figure 5 It is a structural diagram of a medical device provided in an embodiment of the present application, wherein the medical device comprises: one or more processors, one or more memories, one or more communication interfaces, and one or more programs; the one or more programs are stored in the memories and are configured to be executed by the one or more processors.

[0094] The above program includes instructions for performing the following steps:

[0095] Acquire a first pumping flow rate and a second pumping flow rate, wherein the first pumping flow rate is a maximum pumping flow rate in a first cycle when the ventricular assist device operates at a target speed, and the second pumping flow rate is a minimum pumping flow rate in the first cycle when the ventricular assist device operates at the target speed, and the first cycle is a time interval between adjacent first pumping flows or second pumping flows;

[0096] Calculating a target value, wherein the target value is a ratio of a target flow difference to a first average flow, wherein the target flow difference is a difference between the first pumping flow and the second pumping flow, and the first average flow is an average pumping flow of the ventricular assist device in the first cycle;

[0097] Whether the ventricular assist device is abnormal is determined based on the first pumping flow rate, the second pumping flow rate, and the target value.

[0098] Among them, all relevant contents of each scenario involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0099] It should be understood that the above-mentioned memory may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type.

[0100] In the embodiment of the present application, the processor of the above-mentioned device may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0101] It should be understood that the "at least one" involved in the embodiments of the present application refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0102] Furthermore, unless otherwise specified, ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, timing, priority or importance of multiple objects. For example, the first information and the second information are only used to distinguish different information, and do not indicate the difference in content, priority, sending order or importance of the two types of information.

[0103] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software units in a processor for execution. The software unit can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor executes the instructions in the memory, and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0104] An embodiment of the present application also provides a computer storage medium, wherein the computer storage medium stores a computer program for electronic data exchange, and the computer program enables a computer to execute part or all of the steps of any method recorded in the above method embodiments.

[0105] The present application also provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute some or all of the steps of any method described in the above method embodiment. The computer program product may be a software installation package.

[0106] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0107] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0108] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the above-mentioned units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0109] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0110] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0111] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or all or part of the technical solution, can be embodied in the form of a software product, which is stored in a memory and includes several instructions for a computer device (which can be a personal computer, server or TRP, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned memory includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0112] A person skilled in the art may understand that all or part of the steps in the various methods of the above embodiments may be completed by instructing the relevant hardware through a program, and the program may be stored in a computer-readable memory, which may include a flash drive, ROM, RAM, a magnetic disk or an optical disk, etc.

[0113] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for detecting abnormality of a ventricular assist device, characterized in that: The method comprises: Acquire a first pumping flow rate and a second pumping flow rate, wherein the first pumping flow rate is a maximum pumping flow rate in a first cycle when the ventricular assist device operates at a target speed, and the second pumping flow rate is a minimum pumping flow rate in the first cycle when the ventricular assist device operates at the target speed, and the first cycle is a time interval between adjacent first pumping flows or second pumping flows; Calculating a target value, wherein the target value is a ratio of a target flow difference to a first average flow, wherein the target flow difference is a difference between the first pumping flow and the second pumping flow, and the first average flow is an average pumping flow of the ventricular assist device in the first cycle; Whether the ventricular assist device is abnormal is determined based on the first pumping flow rate, the second pumping flow rate, and the target value.

2. The method according to claim 1, characterized in that The determining whether the ventricular assist device is abnormal according to the first pumping flow rate, the second pumping flow rate and the target value comprises: If the first pumping flow rate is greater than or equal to a first preset flow rate, and the second pumping flow rate is greater than or equal to a second preset flow rate, it is determined that the ventricular assist device is operating abnormally, resulting in aortic valve regurgitation; If the target value is less than the first value, determining that the aortic valve has moderate regurgitation; If the target value is less than a second value, the aortic valve is determined to have high regurgitation, and the second value is less than the first value.

3. The method according to claim 1, characterized in that The method further comprises: Acquire a target characteristic curve, wherein the target characteristic curve is a pressure-flow characteristic curve when the ventricular assist device runs at the target speed; Determining the first preset flow rate according to the target characteristic curve, the first preset flow rate being the pumping flow rate of the ventricular assist device at a preset pressure difference; 4. The method according to claim 3, characterized in that The method further comprises: Determining a target pressure difference corresponding to the first average flow rate according to the target characteristic curve; If, within the second cycle, the target pressure difference continues to be equal to the preset pressure difference, and the target value continues to be greater than or equal to the second preset flow rate, it is determined that the position of the ventricular assist device is abnormal and the second cycle is greater than the first cycle.

5. The method according to claim 1, characterized in that The method further comprises: Obtain a first flow threshold and a second flow threshold; adjusting the target speed to adjust the first flow threshold and the second flow threshold; If the first flow threshold and the second flow threshold are both equal to the second pumping flow, it is determined that the ventricular assist device can be de-pumped.

6. The method according to claim 5, characterized in that Adjusting the target speed to adjust the first flow threshold and the second flow threshold includes: collecting the i-th pumping flow rate and the i+1-th pumping flow rate when the ventricular assist device is running at the target speed, where i is a positive integer; If the i-th pumping flow rate is greater than the i+1-th pumping flow rate, and the i+1-th pumping flow rate is greater than the first flow rate threshold, the target speed is reduced at a first acceleration, and the first flow rate threshold is reduced; If the i-th pumping flow rate is less than the i+1-th pumping flow rate, and the i+1-th pumping flow rate is less than the second flow rate threshold, then increasing the target speed at a second acceleration, and increasing the second flow rate threshold; Let i=i+1, and repeat the above steps until the first time duration is reached or the target speed exceeds the preset speed range.

7. The method according to claim 1, characterized in that The method further comprises: Obtaining the second pumping flow rate in n first cycles, where n is a positive integer; If the n second pumping flow rates are all smaller than the second preset flow rate, it is determined that there is reflux in the ventricular assist device and an alarm is issued.

8. A control unit for a ventricular assist device, characterized in that: The control unit comprises one or more processors, wherein the one or more processors are configured to: Acquire a first pumping flow rate and a second pumping flow rate, wherein the first pumping flow rate is a maximum pumping flow rate in a first cycle when the ventricular assist device operates at a target speed, and the second pumping flow rate is a minimum pumping flow rate in the first cycle when the ventricular assist device operates at the target speed, and the first cycle is a time interval between adjacent first pumping flows or second pumping flows; Calculating a target value, wherein the target value is a ratio of a target flow difference to a first average flow, wherein the target flow difference is a difference between the first pumping flow and the second pumping flow, and the first average flow is an average pumping flow of the ventricular assist device in the first cycle; Whether the ventricular assist device is abnormal is determined based on the first pumping flow rate, the second pumping flow rate, and the target value.

9. A ventricular assist device, characterized in that: The ventricular assist device comprises: case; an impeller disposed in the housing; A control unit for controlling the rotation of the impeller, wherein the control unit is used to execute the steps in the method according to any one of claims 1 to 7.

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

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

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