Ventricular assist device and control unit therefor, medical device

Abstract

The application provides a ventricular assist device, a control unit thereof and a medical device. The control unit acquires a target pumping flow curve and a plurality of target voltage curves. The target pumping flow curve is a pumping flow curve of the ventricular assist device when the ventricular assist device operates for a first time length. The target voltage curve is an output voltage curve of a Hall sensor for the first time length. A first feature and a second feature are calculated according to the target pumping flow curve and the plurality of target voltage curves. Whether a thrombus exists in the ventricular assist device is determined according to the first feature and the second feature. The application calculates the features that can determine the thrombus from the operating parameters of the ventricular assist device, and then determines whether the thrombus exists in the ventricular assist device according to the size of the features. The real-time monitoring of the thrombus can be realized without relying on external equipment, and the safety of the user is improved.

Description

Technical Field

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

[0002] Pumps used as mechanical circulation support devices include pumping mechanisms for pumping fluid from one location to another, such as centrifugal pumps and axial flow pumps for pumping blood from the heart to other parts of the body. These pumps achieve the function of pumping fluid by using an impeller disposed within the pump housing to transport fluid through the pump housing from the inlet end to the outlet end.

[0003] Currently, some mechanical circulation support devices use non-contact impeller suspension technology to solve support and energy consumption problems in highly mechanical designs. During pump operation, the high shear force generated by the high-speed rotation of the impeller can damage blood, causing blood clots to form in the bearing clearance between the suspended impeller and the pump casing, thus impairing blood compatibility and affecting pump operation. Summary of the Invention

[0004] This application provides a ventricular assist device and its control unit, as well as a medical device, which can achieve real-time monitoring of thrombi without relying on external devices.

[0005] In a first aspect, embodiments of this application provide a control unit for a ventricular assist device, the ventricular assist device including an impeller, a motor driving the impeller to rotate in a suspended manner, and a plurality of Hall sensors, the control unit being used to perform the following steps: Acquire a target pump flow rate curve and multiple target voltage curves, wherein the target pump flow rate curve is the pump flow rate curve of the ventricular assist device during operation in the first time period, and the target voltage curve is the output voltage curve of the Hall sensor during the first time period; Calculate the first feature and the second feature based on the target pumping flow rate curve and the plurality of target voltage curves; The presence of a thrombus in the ventricular assist device is determined based on the first feature and the second feature.

[0006] Secondly, this application provides a ventricular assist device, the ventricular assist device comprising: impeller; A motor that drives the impeller to rotate in a suspended manner; Multiple Hall sensors; A control unit connected to the plurality of Hall sensors and the motor is configured to perform the following steps: Acquire a target pump flow rate curve and multiple target voltage curves, wherein the target pump flow rate curve is the pump flow rate curve of the ventricular assist device during operation in the first time period, and the target voltage curve is the output voltage curve of the Hall sensor during the first time period; Calculate the first feature and the second feature based on the target pumping flow rate curve and the plurality of target voltage curves; The presence of a thrombus in the ventricular assist device is determined based on the first feature and the second feature.

[0007] Thirdly, embodiments of this application provide a medical device, the medical device including a processor, a memory, a communication interface, and one or more programs, the one or more programs being stored in the memory and configured to be executed by the processor, the programs including instructions for performing some or all of the steps performed by the control unit described in the first aspect above.

[0008] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program for electronic data interchange, wherein the computer program causes a computer to perform some or all of the steps performed by the control unit described in the first aspect.

[0009] The technical solution provided in this application acquires a target pumping flow curve and multiple target voltage curves. The target pumping flow curve is the pumping flow curve of the ventricular assist device during operation within a first time period, and the target voltage curves are the output voltage curves of the Hall sensor during the first time period. A first feature and a second feature are calculated based on the target pumping flow curve and multiple target voltage curves. The presence of a thrombus within the ventricular assist device is determined based on the first and second features. This application calculates thrombus-identifying features from the ventricular assist device's own operating parameters, and then determines the presence of a thrombus within the current ventricular assist device based on the magnitude of these features. This enables real-time thrombus monitoring without relying on external equipment, increasing user safety. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of a ventricular assist system provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a ventricular assist device provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electric motor provided in an embodiment of this application; Figure 4 This is a schematic diagram of a control unit performing thrombus detection according to an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a medical device provided in an embodiment of this application. Detailed Implementation

[0012] To help those skilled in the art better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the description of the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0013] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, software, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but also includes steps or units not listed, or other steps or units inherent to such processes, methods, products, or apparatus.

[0014] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0015] The medical device involved in this application may be a ventricular assist device (VAD), such as an interventional ventricular assist device or an implantable ventricular assist device; the ventricular assist device may be a left ventricular assist device, a right ventricular assist device, or a biventricular assist device; the ventricular assist device may include at least one blood pump, wherein the blood pump is a magnetic levitation pump.

[0016] A ventricular assist device (VAD) can be attached to the heart via a ventricular connection assembly (such as a top ring, ventricular cuff, or ventricular linker). This assembly can be sutured to the heart and connected to a blood pump. The other end of the blood pump can be connected to the ascending aorta via an outlet tube and / or an artificial blood vessel connected to the outlet tube. This allows the VAD to effectively transfer blood from the weakened ventricle and propel it into the aorta, thereby circulating it to the rest of the patient's vascular system and providing ventricular support.

[0017] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a ventricular assist system provided in an embodiment of this application. Figure 1 As shown, the ventricular assist system includes a ventricular assist device 100, an external controller 200, and a transmission assembly 300 connecting the ventricular assist device 100 to the external controller 200. One end of the transmission assembly 300 is connected to a motor inside the ventricular assist device 100, and the other end passes through the patient's abdominal skin to connect to the external controller 200 located outside the body. The external controller 200 is used to monitor the ventricular assist device 100, and can perform functions such as controlling and displaying data of the ventricular assist device 100, fault detection alarms, and data logging. The transmission assembly 300 may be a percutaneous cable, which may include one or more power cables and one or more communication cables.

[0018] like Figures 2-3 As shown, the ventricular assist device 100 includes a housing assembly with an inlet pipe and an impeller 20 for propelling fluid. The housing assembly has a chamber 10. Specifically, the housing assembly includes a first housing and a second housing connected to the first housing, the first housing and the second housing together forming the chamber 10. The housing assembly also has a fluid inlet 14 and a fluid outlet 15 communicating with the chamber 10. The fluid inlet 14 is located on the first housing. The impeller 20 is capable of suspending and rotating within the chamber 10. The rotation of the impeller 20 generates centrifugal force to transport fluid, allowing fluid to enter the chamber 10 from the fluid inlet 14 and exit from the fluid outlet 15. The suspending and rotating of the impeller 20 means that the impeller 20 does not contact the chamber wall of the chamber 10 during rotation.

[0019] The ventricular assist device 100 also includes a motor 30 and a Hall sensor 40 for driving the impeller 20 to levitate and rotate. The housing assembly has opposing first sidewalls 11 and second sidewalls 12. Specifically, the first sidewall 11 is located in the second housing, and the second sidewall 12 is located in the first housing. The motor 30 includes a stator 31 and a rotor 32 positioned on either side of the first sidewall 11. The stator 31 is fixed to the outer side of the first sidewall 11 relative to the chamber 10, and the corresponding rotor 32 is located inside the chamber 10. Furthermore, the rotor 32 is fixedly connected to the impeller 20. When the stator 31 drives the rotor 32 to rotate within the chamber 10, the impeller 20 also rotates synchronously within the chamber 10 along with the rotor 32. The rotation of the impeller 20 can pressurize the fluid within the chamber 10, giving it greater pressure, thereby achieving the fluid pressurization effect of a blood pump.

[0020] It should be noted that, in Figure 2 In one embodiment, the first sidewall 11 and the second sidewall 12 are arranged in a parallel configuration, and the rotation axis 21 of the impeller 20 is perpendicular to both the first sidewall 11 and the second sidewall 12.

[0021] The impeller 20 is annular and has a central hole 25. The fluid inlet 14 is directly opposite the central hole 25 of the impeller 20. The impeller 20 has opposing first surfaces 22 and second surfaces 23, and flow channels 24. The first surface 22 is opposite to the second sidewall 12, and the second surface 23 is opposite to the first sidewall 11. The central hole 25 penetrates both the first and second surfaces 22 and 23. Multiple flow channels 24 extend radially along the annular impeller 20. The flow channels 24 are located between the first and second surfaces 22 and 23. The flow channels 24 communicate with the central hole 25. After entering the central hole 25 of the impeller 20 from the fluid inlet 14, the fluid flows out of the impeller 20 from the flow channels 24, which serve as the main flow channels for the fluid. Adjacent flow channels 24 are separated by the blades of the impeller 20. As the impeller 20 rotates within the flow channels 24, the fluid velocity increases, resulting in a pressurization effect, and then flows out from the fluid outlet 15. The first surface 22 is located on the side of the impeller 20 facing the second sidewall 12. The rotor 32 is housed within the impeller 20; specifically, the rotor 32 is disposed within the impeller 20 and close to the second surface 23. When the impeller 20 is suspended and rotating within the chamber 10, there is a gap between the first surface 22 and the second sidewall 12 of the impeller 20, and a gap between the second surface 23 and the first sidewall 11 of the impeller 20. Secondary flow channels are formed between the first surface 22 and the second sidewall 12, and between the second surface 23 and the first sidewall 11. After fluid flows into the impeller 20, a small portion of the fluid flows out from the flow channel 24 of the impeller 20 and does not flow directly to the fluid outlet 15, but instead re-enters the main flow channel through the secondary flow channel.

[0022] Furthermore, the rotor 32 can be composed of multiple magnets arranged at equal angular intervals along the same circle, such that adjacent magnetic poles are different from each other. That is, magnets with the N pole facing the stator 31 and magnets with the S pole facing the stator 31 are alternately arranged at equal angular intervals along the same circle. The stator 31 can also include multiple magnetic bodies arranged at equal angular intervals along the same circle opposite to the multiple magnets of the rotor 32. The base of each magnetic body is engaged with a magnetic yoke, and each magnetic body is wound with a coil.

[0023] For example, such as Figure 3 As shown, the stator 31 is generally annular and includes multiple winding units 310. These winding units 310 are arranged symmetrically around a circumference. For example, each winding unit 310 includes stator teeth 311 and stator coils 312. The stator 31 includes two three-phase windings, with three adjacent winding units 310 forming a single three-phase winding.

[0024] The ventricular assist device 100 also includes a control unit 33, which is plate-shaped, specifically a circular PCB circuit board. The PCB circuit board may include an upper surface and a lower surface, connected by a flexible data cable. The upper surface is located on the side of the stator 31 facing the rotor 32, and the lower surface is located on the side of the stator 31 away from the rotor 32. A Hall sensor 40 is disposed on either the upper or lower surface of the control unit 33 and is electrically connected to the control unit 33. For example... Figure 2 Hall sensors 40 are disposed on the upper surface of the control unit 33. There are multiple Hall sensors 40 (six in the figure); a Hall sensor 40 is disposed between every two adjacent stator teeth 311. The Hall sensors 40 are used to measure the axial distance between the rotor 32 and the stator 31, and transmit the measured distance to the control unit 33.

[0025] Furthermore, the control unit 33 is used to monitor and control the starting and subsequent operation of the motor 30. The control unit 33 can be a module independent of the stator 31, or it can be built into the stator 31. Figure 2 In this embodiment, the control unit 33 is an independent module, electrically connected to both the Hall sensor 40 and the stator 31. The control unit 33 can determine the suspension position of the rotor 32 in the impeller 20 relative to the stator 31 based on the received distance signal, and thus determine the axial position of the impeller 20 within the chamber 10. By controlling the power of the stator 31, the control unit 33 can control the magnetic force between the stator 31 and the rotor 32, thereby achieving the effect of controlling the rotational speed and suspension position of the rotor 32 in the impeller 20.

[0026] The control unit 33 includes hardware and software for controlling various aspects of the operation of the motor 30. The control unit 33 can be coupled to the stator 31 via an interface to collect at least one piece of data from the stator 31. This at least one piece of data may include the measured current flowing through the stator 31, data measured by the Hall sensor 40, motor speed, pressure difference across the pump, flow pulsation, fluid velocity, etc.

[0027] For example, the Hall sensor 40 is used to measure the distance between the impeller 20 and the first sidewall 11, and transmits this distance value to the control unit 33 via a flexible data line. Specifically, the Hall sensor 40 is positioned relative to the rotor 32 on the impeller 20 via a path. As the impeller 20 rotates, causing the S and N poles of the rotor to alternately pass near the Hall sensor, the signal level of the Hall sensor, representing the magnetic flux intensity, changes sinusoidally. Therefore, by detecting the time change of the Hall sensor's output signal, the positional relationship between the rotor 32 and the stator 31 can be detected, and the rotational speed of the impeller 20 with current flowing through the stator 31 can be calculated.

[0028] The high shear force during the rotation of impeller 20 can damage blood cells, causing more platelets to remain within the ventricular assist device 100. These platelets then clot and adhere to the secondary flow channel, fluid inlet 14, fluid outlet 15, and impeller 20, forming thrombi at these locations. The threat of thrombotic complications caused by the ventricular assist device 100 remains unresolved. Intra-pump thrombus formation can lead to serious complications, making early detection and determination of thrombus location crucial for the reliability of the ventricular assist device 100.

[0029] Based on this, the control unit 33 of this application acquires the pump flow curve and the output voltage curve of multiple Hall sensors 40 during the operation of the ventricular assist device 100 in real time. It calculates the first feature and the second feature based on the pump flow curve and the multiple output voltage curves, and then determines whether there is a thrombus in the ventricular assist device 100 by comparing the values ​​of the first feature and the second feature. This allows for real-time monitoring of thrombi without relying on external equipment, thereby increasing user safety.

[0030] Based on the above description, this application will now be described from the perspective of method examples.

[0031] Please see Figure 4 , Figure 4 This application provides a schematic diagram of a control unit performing thrombus detection, applicable to, for example... Figures 1-3 The ventricular assist device 100 is shown. (As shown in the image) Figure 4 As shown, the method includes the following steps.

[0032] S410. Obtain the target pumping flow curve and multiple target voltage curves, wherein the target pumping flow curve is the pumping flow curve of the ventricular assist device during operation in the first time period, and the target voltage curve is the output voltage curve of the Hall sensor in the first time period.

[0033] Hall sensors 40 can be used to detect the levitation height of rotor 32. During the rotation of rotor 32, each Hall sensor 40 can detect its corresponding area (e.g., Figure 3 As shown, the levitation height of the rotor 32 (located directly above each Hall sensor 40) varies. When the rotor 32 is tilted due to unbalanced forces, the output voltage value of the Hall sensor 40 at different positions will change accordingly. The secondary flow channel within the ventricular assist device 100 is an auxiliary flow channel, and its pumped flow rate accounts for a small portion of the total flow rate. However, when a thrombus is present in the secondary flow channel, especially when the thrombus is large, the thrombus adhering to the first housing and / or the second housing will cause uneven axial magnetic levitation force of the rotor 32 to be distributed circumferentially, resulting in significant tilting of the rotor 32. That is, the presence of the thrombus prevents the rotor 32 from reaching the preset axial position, thus causing the amplitude of the levitation position of the rotor 32 corresponding to the thrombus area to be less than or greater than the amplitude of the levitation position calibrated when there is no thrombus. After the rotor 32 tilts, the axial clearance between the rotor 32 and the stator 31 will show a circumferential difference, that is, the clearance between some rotors 32 and the stator 31 increases, while the clearance between other rotors 32 and the stator 31 decreases. An increase in the gap between rotor 32 and stator 31 will correspondingly decrease the voltage amplitude output by Hall sensor 40; conversely, a decrease in the gap will correspondingly increase the voltage amplitude output by Hall sensor 40. The difference in gap between rotor 32 and stator 31 is directly reflected in the output voltage of multiple Hall sensors 40. Therefore, control unit 33 can acquire the output voltage curves of multiple Hall sensors 40 and determine whether rotor 32 is tilted by analyzing the differences between these curves, thereby determining whether thrombus is present in the ventricular assist device 100.

[0034] Furthermore, when the ventricular assist device 100 is operating normally, its pump flow rate curve is similar to the preset flow rate curve, and the fluctuation of the pump flow rate curve is small. However, when a thrombus is present in the ventricular assist device 100, the thrombus will disrupt the hydrodynamic balance of the ventricular assist device 100 (such as the occurrence of turbulence), leading to abnormalities in the pump flow rate (such as an increase in the fluctuation amplitude of the pump flow rate, a significant decrease in the pump flow rate, etc.). Therefore, the control unit 33 can acquire the pump flow rate curve of the ventricular assist device 100 during operation and determine whether there is a thrombus in the ventricular assist device 100 by detecting whether there is an abnormality in the pump flow rate curve.

[0035] Specifically, when the ventricular assist device 100 is activated and running at a preset constant speed, the control unit 33 can acquire the target pumping flow curve and the target voltage curve of multiple Hall sensors 40 within a first time period. Subsequently, the target pumping flow curve and multiple target voltage curves are used to determine whether there is a thrombus in the ventricular assist device 100.

[0036] The preset rotational speed is within the allowable rotational speed range of the ventricular assist device 100, which is 2200 RPM to 4300 RPM. For example, the preset rotational speed can be set to 3000 RPM. The first duration can be set according to actual needs, such as 3s, 4s, 5s, 6s, 10s, etc.

[0037] S420. Calculate the first feature and the second feature based on the target pumping flow rate and the plurality of target voltage curves.

[0038] The first feature describes the overall tilt amplitude of rotor 32, and the second feature describes the stability of the pumping flow rate of ventricular assist device 100. When the overall tilt amplitude of rotor 32 far exceeds the normal value, i.e., rotor 32 exhibits significant tilt, it indicates that the current rotor 32 is under uneven circumferential force, and thrombus in ventricular assist device 100 is affecting the balance of rotor 32. Simultaneously, when no other abnormalities are found in ventricular assist device 100, but the target pumping flow rate curve of ventricular assist device 100 shows abnormal fluctuations, it indicates that thrombus may be present in ventricular assist device 100. Therefore, by calculating the first and second features, it can be determined whether thrombus exists within ventricular assist device 100.

[0039] Optionally, in calculating the first feature and the second feature based on the target pumping flow rate curve and the plurality of target voltage curves, the control unit is specifically configured to: sample the plurality of target voltage curves respectively according to a preset sampling frequency to obtain a plurality of voltage sampling points for each target voltage curve; calculate the standard deviation of each target voltage curve based on the plurality of voltage sampling points to obtain a plurality of first standard deviations; determine the average value of the plurality of first standard deviations as the first feature; sample the target flow rate from the target pumping flow rate curve according to the preset sampling frequency; and determine the quantity of the target flow rate as the second feature, wherein the first derivative of the target flow rate is less than a preset value.

[0040] The differences between the target voltage curves of multiple Hall sensors 40 can be characterized by the magnitude of the standard deviation of the output voltages of the multiple Hall sensors 40. A larger average standard deviation indicates a greater difference between the multiple target voltage curves, which in turn indicates a greater tilt of the rotor 32 and a higher probability of thrombus presence within the ventricular assist device 100. The stability of the pumping flow rate can be characterized by the number of sampling points with stable flow rates without significant fluctuations in the target pumping flow rate curve. A smaller number of sampling points with stable flow rates without significant fluctuations indicates greater fluctuations in the target pumping flow rate curve and a higher probability of thrombus presence within the ventricular assist device 100.

[0041] During the operation of the ventricular assist device 100, the control unit 100 receives the output voltage feedback from multiple Hall sensors 40 in real time and estimates the pumping flow rate of the ventricular assist device 100, and generates corresponding curves to obtain the pumping flow rate curve and multiple output voltage curves. Then, the pumping flow rate curve and multiple output voltage curves are analyzed and processed using a first time period as a sliding window.

[0042] For example, a sliding window with a length of 4 seconds and a step size of 1 second is used to divide the pump flow curve and the output voltage curve of each Hall sensor 40, resulting in a target pump flow curve and multiple target voltage curves within the sliding window. Then, the target pump flow curve and multiple target voltage curves are sampled at a preset sampling frequency to obtain multiple flow sampling points for the target pump flow curve and multiple voltage sampling points for each target voltage curve. The standard deviation of the multiple voltage sampling points is calculated to obtain the first standard deviation of the output voltage curve of each Hall sensor 40 within the sliding window. The average of the calculated multiple first standard deviations is then used as the first feature. The first derivative of each flow sampling point can be calculated simultaneously. If the first derivative of the flow sampling point is less than a preset value, it indicates that the rate of change of the pump flow at that sampling point is small, and the pump flow at that sampling point can be considered stable without significant fluctuations. The preset value can be set based on the fluctuation value of the pump flow curve for each patient when the ventricular assist device 100 is operating normally at a preset speed; that is, the preset value can be set based on the preset speed and the patient's actual hemodynamics, and is not limited here.

[0043] S430. Determine whether there is a thrombus in the ventricular assist device based on the first feature and the second feature.

[0044] The first feature can be used to determine whether the rotor 32 is tilted, and the second feature can be used to determine whether the pumping flow of the ventricular assist device 100 is stable. The control unit 33 can determine whether there is a thrombus in the ventricular assist device 100 based on whether the first and second features are abnormal.

[0045] Optionally, in determining whether there is a thrombus in the ventricular assist device based on the first feature and the second feature, the control unit is specifically configured to: if the first feature is greater than or equal to a first value, then determine that there is a thrombus in the ventricular assist device; otherwise, compare the second feature and the second value; if the second feature is greater than the second value, then determine that there is no thrombus in the ventricular assist device; otherwise, determine that there is a thrombus in the ventricular assist device.

[0046] Within the ventricular assist device 100, thrombi can easily adhere to the secondary flow channel, impeller 20, fluid inlet 14, and fluid outlet 15. When thrombi are present in the secondary flow channel, the rotor 32 experiences uneven force, making it prone to tilting. Therefore, the control unit 33 first determines whether the rotor 32 is significantly tilted by judging whether a first feature is abnormal. The greater the tilt of the rotor 32, the larger the thrombus present in the secondary flow channel. If the first feature determines that a thrombus is present in the secondary flow channel of the ventricular assist device 100, the detection result is directly output; if the first feature is not abnormal, i.e., the rotor 32 is not significantly tilted, then the presence of a thrombus is determined by judging whether a second feature is abnormal. When thrombi are present in the ventricular assist device 100, the blood flow channels of the ventricular assist device 100 are blocked, restricting the blood flow capacity and significantly reducing the pumping flow rate of the ventricular assist device 100. For example, a thrombus at fluid inlet 14 can obstruct blood flow, causing an overall decrease and abnormal fluctuation in the pumping flow rate of the ventricular assist device 100; a thrombus on the impeller 20 can disrupt its power output, causing periodic fluctuations in the pumping flow rate of the ventricular assist device 100; and a thrombus at fluid outlet 15 can obstruct blood flow, causing reverse fluctuations in the pumping flow rate of the ventricular assist device 100. Therefore, if the second characteristic is abnormal in the absence of other abnormal alarms in the ventricular assist device 100, it is considered that a thrombus exists within the ventricular assist device 100; otherwise, the ventricular assist device 100 is considered to be operating normally. If the second characteristic is normal, it indicates that the pumping flow rate of the ventricular assist device 100 is highly stable throughout, ruling out thrombi at other locations, thus indicating that the ventricular assist device 100 is operating normally.

[0047] The first characteristic is the dispersion of the output voltage of the Hall sensor 40 at different positions, which can be used to characterize the tilt of the rotor 32. The first value is greater than the maximum allowable tilt of the rotor 32 during normal operation of the ventricular assist device 100. If the first characteristic is greater than or equal to the first value, it indicates that the current tilt of the rotor 32 exceeds the allowable normal value. Regardless of whether the pumping flow of the ventricular assist device 100 is stable, it is directly determined that there is a thrombus in the secondary flow channel of the ventricular assist device 100, and the control unit 33 outputs that there is a thrombus in the secondary flow channel of the ventricular assist device 100. If the first characteristic is less than the first value, it indicates that the current tilt of the rotor 32 is within the allowable normal range, and the presence of a thrombus in the secondary flow channel can be ruled out. The second characteristic is then used to determine whether there is a thrombus at other positions of the ventricular assist device 100. If the second characteristic is greater than the second value, it indicates that the pumping flow rate of the ventricular assist device 100 is highly stable and without abnormal fluctuations throughout the first time period, and the control unit 33 can determine that the ventricular assist device 100 is currently normal and free of thrombus. If the second characteristic is less than or equal to the second value, it indicates that the pumping flow rate of the ventricular assist device 100 has abnormal fluctuations, and thrombus exists in other locations within the ventricular assist device 100 except for the secondary flow channel. Furthermore, the ventricular assist device has a risk of thrombosis at the fluid inlet 14, fluid outlet 15, or impeller 20.

[0048] The first and second values ​​can be set according to the first duration and the preset sampling frequency. Within the first duration, the higher the preset sampling frequency and the more sampling points, the larger the first and second values ​​will be. For example, when the first duration is 4 seconds and the preset sampling frequency is set to 100Hz, the first value can be set to 71.7 and the second value to 337.5. Alternatively, when the first duration is 5 seconds and the preset sampling frequency is 200Hz, the first value can be set to 179.25 and the second value to 843.75.

[0049] In this application, the presence of a thrombus within the ventricular assist device 100 is determined by comparing the values ​​of a first feature and a second feature. This enables real-time monitoring of thrombi without relying on external devices, increasing user safety. Furthermore, the determination is made solely through simple sliding window statistics and threshold comparison, resulting in low computational complexity and short processing time, making it perfectly compatible with implantable ventricular assist devices 100.

[0050] In one possible example, the control unit is further configured to: acquire a target rotational speed curve, the target rotational speed curve being the rotational speed curve of the ventricular assist device operating within a first duration; calculate a third feature based on the plurality of target voltage curves; calculate a fourth feature based on the target rotational speed curve; and determine the location of the thrombus based on the first feature, the second feature, the third feature, and the fourth feature.

[0051] In this application, the first feature can be used to determine whether a thrombus exists in the secondary flow channel within the ventricular assist device 100. If no thrombus is found in the secondary flow channel, the second feature can be used to further determine whether a thrombus exists within the ventricular assist device 100. Therefore, after determining that a thrombus exists within the ventricular assist device 100, its location can be further determined. The location of the thrombus within the ventricular assist device 100 affects the operating parameters of the ventricular assist device differently. Therefore, the control unit 33 can acquire the third and fourth features to further determine the specific location of the thrombus within the ventricular assist device 100.

[0052] The third characteristic can be used to measure the frequency of rotor 32 tilt. During the levitation and rotation of rotor 32, electromagnetic interference generated by internal or external noise can cause abnormal voltage signals output by Hall sensor 40, leading to misjudging the normal state of rotor 32 as tilt. Specifically, the mean of the standard deviation of the output voltages of multiple Hall sensors 40 is amplified by abnormal values ​​such as single electromagnetic interference and fluid pulsation, causing the normal state of rotor 32 to be misjudged as tilt, thus affecting the accuracy of thrombus detection. Therefore, to reduce the problem of abnormal voltage signals output by Hall sensor 40 caused by noise or blood flow pulsation, this application introduces a median rotor tilt level value (median). The median rotor tilt level reflects the basic tilt level of rotor 32. A higher median rotor tilt level value indicates that the sampling points of the output voltage of Hall sensor 40 are not affected by noise and can eliminate interference from extreme values, thus accurately reflecting the true tilt level of rotor 32. Fluid inlet 14 is the only channel for blood to enter the ventricular assist device 100. If a thrombus is present at fluid inlet 14, it will block blood from entering the ventricular assist device 100, resulting in abnormal pumping flow. However, the thrombus will not directly contact the rotor 32. Therefore, when a thrombus is present at fluid inlet 14, the rotor 32 remains stable without tilting or tilts within the normal range, only resulting in abnormal pumping flow. Thus, by acquiring the third characteristic, it can be determined whether the thrombus is currently located at fluid inlet 14.

[0053] The fourth feature is used to measure the rotational stability of the impeller 20. The impeller 20 is the core power component of the ventricular assist device 100, and it comes into direct contact with blood. Therefore, blood can easily stagnate or adhere to the impeller 20, especially when the rotational speed of the ventricular assist device 100 is low. Thrombi formed at the impeller 20 location can directly adhere to the blades of the impeller 20, disrupting its dynamic balance and causing significant abnormal fluctuations in rotational speed. The control unit 33 can further determine whether the thrombus is located on the impeller 20 or at the fluid outlet 15 by acquiring the fourth feature.

[0054] Specifically, in calculating the third feature based on the plurality of target voltage curves and the fourth feature based on the target speed curve, the control unit is configured to: determine the median of the plurality of first standard deviations as the third feature; sample the target speed curve according to a preset sampling frequency to obtain a plurality of speed sampling points; and determine the standard deviation of the plurality of speed sampling points as the fourth feature.

[0055] The third feature (rotor tilt mid-level value) can be represented by the median of the standard deviations of the output voltages of multiple Hall sensors 40. The magnitude of the median standard deviation measures the robustness of the output voltages of the Hall sensors 40. The fourth feature can be represented by the standard deviation of the impeller 20 rotational speed. The standard deviation of the rotational speed reflects the degree to which the rotational speed deviates from the average rotational speed within the first time period, and can be used to measure the stability of the rotational speed. For example, the control unit 33 can divide the rotational speed curve of the ventricular assist device and the output voltage curve of each Hall sensor 40 within the first time period using a sliding window with a length of 4 seconds and a step size of 1 second, obtaining the target rotational speed curve and multiple target voltage curves within the sliding window. Then, the target rotational speed curve and multiple target voltage curves are sampled with a preset sampling frequency to obtain multiple rotational speed sampling points of the target rotational speed curve and multiple voltage sampling points of each target voltage curve. The standard deviation of the multiple voltage sampling points is calculated to obtain the first standard deviation of the output voltage curve of each Hall sensor 40 within the sliding window. Finally, the median of the first standard deviations of the multiple Hall sensors 40 is used as the third feature, and the standard deviation of the multiple rotational speed sampling points is used as the fourth feature.

[0056] In this application, the control unit 33 can determine whether there is a thrombus in the current ventricular assist device 100 based on the first feature and the second feature. If there is a thrombus, the location of the thrombus can be further determined by the first feature, the second feature, the third feature and the fourth feature.

[0057] Optionally, in determining the location of the thrombus based on the first feature, the second feature, the third feature, and the fourth feature, the control unit is specifically configured to: determine that a thrombus exists in the secondary flow channel of the ventricular assist device if the first feature is greater than the first value; determine that a thrombus exists at the fluid inlet of the ventricular assist device if the first feature is less than or equal to the first value, the second feature is less than or equal to the second value, and the third feature is less than or equal to the third value; determine that a thrombus exists at the fluid outlet of the ventricular assist device if the first feature is less than or equal to the first value, the second feature is less than or equal to the second value, the third feature is greater than the third value, and the fourth feature is less than or equal to the fourth value; and determine that a thrombus exists at the impeller of the ventricular assist device if the first feature is less than or equal to the first value, the second feature is less than or equal to the second value, the third feature is greater than the third value, and the fourth feature is greater than the fourth value.

[0058] As blood flows through the ventricular assist device 100, thrombi can easily accumulate at the fluid inlet 14, impeller 20, secondary flow channel, and fluid outlet 15. The control unit 33 determines the presence and location of thrombi within the ventricular assist device 100 through four layers of judgment. The first layer of judgment determines whether the rotor 32 is tilted, thereby determining the presence of thrombi in the secondary flow channel of the ventricular assist device 100. If the rotor 32 is tilted beyond the normal range, a thrombus is confirmed to exist in the secondary flow channel of the ventricular assist device 100; if the rotor 32 is not tilted or its tilt is within the normal range, the process proceeds to the second layer of judgment. The second layer of judgment determines whether the pumping flow rate of the ventricular assist device 100 fluctuates abnormally. If the pumping flow rate fluctuates abnormally, a thrombus is confirmed to exist within the ventricular assist device 100, and the control unit 33 can further determine the location of the thrombus through the third and fourth features. If the pumping flow rate of the ventricular assist device 100 is normal and without abnormal fluctuations, it can be directly determined that the current ventricular assist device 100 is normal and free of thrombus. After determining through the second feature that a thrombus exists within the ventricular assist device 100 and that the thrombus is not located in the secondary flow channel, the third-level judgment is initiated. The third-level judgment involves determining the tilting frequency of the rotor 32 through the third feature. If the tilting frequency of the rotor 32 is within the normal range, i.e., the rotor 32 is stable without significant tilting, and the pumping flow rate of the ventricular assist device 100 is abnormal while the rotor 32 is not abnormally tilted, then it is determined that a thrombus exists at the fluid inlet 14 of the current ventricular assist device 100. If the tilting frequency of the rotor 32 exceeds the normal range, i.e., the rotor 32 has a slight abnormal tilt, and the pumping flow rate of the ventricular assist device 100 is abnormal while the rotor 32 has a slight abnormal tilt, the control unit can rule out the possibility of a thrombus at the fluid inlet 14 of the current ventricular assist device 100 and proceed to the fourth-level judgment. The fourth judgment is to determine the stability of rotor 32 through the fourth feature. If rotor 32 shows obvious abnormal vibration, it is determined that there is a thrombus on the impeller of the current ventricular assist device 100. If rotor 32 runs smoothly without abnormal vibration or the vibration is within the normal range, it is determined that there is a thrombus at the fluid outlet 15 of the current ventricular assist device 100 when there is a thrombus in the ventricular assist device 100 and the pumping flow has abnormal fluctuations.

[0059] In this application, the control unit 33 can determine whether there is a thrombus and the location of the thrombus in the current ventricular assist device 100 through four-layer judgment. This judgment method is simple and easy to implement, and can realize real-time monitoring of thrombi without relying on external equipment. It can also distinguish thrombi in various different locations, which can provide precise guidance for clinical intervention.

[0060] The third and fourth values ​​are determined based on the first duration and the preset sampling frequency. Within the first duration, a higher preset sampling frequency results in more sampling points, leading to larger third and fourth values. For example, when the first duration is 4 seconds and the preset sampling frequency is set to 100Hz, the third value can be set to 63.8 and the fourth value to 4.5 RPM. Alternatively, when the first duration is 5 seconds and the preset sampling frequency is 200Hz, the third value can be set to 159.5 and the fourth value to 11.25.

[0061] Specifically, if the first characteristic is greater than the first value, it indicates that the rotor 32 tilts beyond the normal range, thus confirming the presence of a thrombus in the secondary flow channel of the ventricular assist device 100; if the first characteristic is less than or equal to the first value, the second characteristic is less than or equal to the second value, and the third characteristic is less than or equal to the third value, it indicates that the pumping flow of the ventricular assist device 100 is abnormal, but the rotor 32 does not tilt abnormally, thus confirming the presence of a thrombus at the fluid inlet 14 of the ventricular assist device; if the first characteristic is less than or equal to the first value, the second characteristic is less than or equal to the second value, and the third characteristic is greater than the third value... If the fourth characteristic is less than or equal to the fourth value, it indicates that there is a thrombus in the ventricular assist device 100 and the pumping flow has abnormal fluctuations, then it can be determined that there is a thrombus at the fluid outlet 15 of the ventricular assist device 100; if the first characteristic is less than or equal to the first value, the second characteristic is less than or equal to the second value, the third characteristic is greater than the third value, and the fourth characteristic is greater than the fourth value, it indicates that the pumping flow of the ventricular assist device 100 is abnormal and the rotor 32 has a slight abnormal tilt and obvious abnormal shaking, then it can be determined that there is a thrombus at the impeller 20 of the ventricular assist device.

[0062] Furthermore, the control unit is also configured to: issue an alarm in a first manner when a thrombus is present at the fluid inlet or the impeller of the ventricular assist device; and issue an alarm in a second manner when a thrombus is present at the secondary flow channel or the fluid outlet of the ventricular assist device.

[0063] When a thrombus is detected within the ventricular assist device 100 and its location is determined, the control unit 33 can also issue an alarm. The alarm level varies depending on the location of the thrombus. For example, if a thrombus is present at the fluid inlet 14, it will not only obstruct blood flow into the ventricular assist device, but may also enter the ventricular assist device 100 through the fluid inlet 14 and adhere to the impeller 20. The presence of a thrombus at the impeller 20 will alter the hydrodynamic environment within the ventricular assist device 100, leading to uneven local blood flow velocity or the generation of eddies. In severe cases, this could even cause pump failure, systemic embolism (such as cerebral infarction), or severe hemolytic reactions. Therefore, if a thrombus is detected at the fluid inlet 14 or the impeller 20 of the ventricular assist device 100, an alarm will be triggered in the first manner. The first manner involves the control unit 33 sending an alarm signal to the external controller 200, which instructs the external controller 200 to activate the alarm with high-frequency vibration, flashing red indicator lights, and displaying a message on the screen: "Serious thrombus, please seek immediate medical attention." If a thrombus is detected in the secondary flow channel or fluid outlet 15 of the ventricular assist device 100, an alarm is triggered in a second manner. In this second manner, the control unit 33 sends an alarm signal to the external controller 100, which instructs the external controller 200 to activate the alarm with low-frequency vibration, flashing yellow indicator lights, and a message "Minor thrombus, follow-up examination recommended soon" displayed on the screen.

[0064] As can be seen, this application proposes a control unit for a ventricular assist device (VAD), which acquires a target pump flow curve and multiple target voltage curves. The target pump flow curve is the pump flow curve of the VAD during operation within a first time period, and the target voltage curves are the output voltage curves of the Hall sensor within the first time period. A first feature and a second feature are calculated based on the target pump flow curve and multiple target voltage curves. The presence of a thrombus within the VAD is determined based on the first and second features. This application calculates thrombus-identifying features from the VAD's own operating parameters, and then determines the presence of a thrombus within the VAD based on the magnitude of these features. This allows for real-time thrombus monitoring without relying on external equipment, increasing user safety.

[0065] The above primarily describes the solutions of the embodiments of this application from the perspective of the method execution process. It is understood that, in order to achieve the above functions, the network device includes corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments provided herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0066] For example, an embodiment of this application provides a ventricular assist device, the ventricular assist device comprising: impeller; A motor that drives the impeller to rotate in a suspended manner; Multiple Hall sensors; A control unit connected to the plurality of Hall sensors and the motor is configured to perform the following steps: Acquire a target pump flow rate curve and multiple target voltage curves, wherein the target pump flow rate curve is the pump flow rate curve of the ventricular assist device during operation in the first time period, and the target voltage curve is the output voltage curve of the Hall sensor during the first time period; Calculate the first feature and the second feature based on the target pumping flow rate curve and the plurality of target voltage curves; The presence of a thrombus in the ventricular assist device is determined based on the first feature and the second feature.

[0067] For example, this application also provides a medical device that includes the control unit 33 or the ventricular assist device 100 described above.

[0068] The control unit 33 of each of the above solutions has the 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.

[0069] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of a medical device provided in an embodiment of this application. The medical device includes: 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 configured to be executed by the one or more processors.

[0070] The above procedure includes instructions for performing the following steps: Acquire a target pump flow rate curve and multiple target voltage curves. The target pump flow rate curve is the pump flow rate curve of the ventricular assist device during operation in the first time period, and the target voltage curve is the output voltage curve of the Hall sensor during the first time period. Calculate the first feature and the second feature based on the target pumping flow rate curve and the plurality of target voltage curves; The presence of a thrombus in the ventricular assist device is determined based on the first feature and the second feature.

[0071] All relevant content in each scenario involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0072] It should be understood that the aforementioned memory may include read-only memory and random access memory, and provides instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store information about the device type.

[0073] In the embodiments of this application, the processor of the above-described device may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0074] It should be understood that "at least one" in the embodiments of this application refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single 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, and c can be single or multiple.

[0075] Furthermore, unless otherwise stated, the ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects and are not used to limit the order, timing, priority, or importance of multiple objects. For example, "first information" and "second information" are only used to distinguish different information and do not indicate differences in the content, priority, sending order, or importance of these two types of information.

[0076] In implementation, each step of the above method can be completed by integrated logic circuits in the processor's hardware or by instructions in software. The steps of the method disclosed in the embodiments of this application can be directly manifested as execution by a hardware processor, or as a combination of hardware and software units within the processor. The software units can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor executes the instructions in the memory, combining them with its hardware to complete the steps of the above method. To avoid repetition, detailed descriptions are omitted here.

[0077] This application also provides a computer storage medium storing a computer program for electronic data interchange, which causes a computer to perform some or all of the steps of any of the methods described in the above method embodiments.

[0078] This application also provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program operable to cause a computer to perform some or all of the steps of any of the methods described in the above method embodiments. This computer program product can be a software installation package.

[0079] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0080] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0081] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0082] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of this application, depending on actual needs.

[0083] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0084] If the aforementioned integrated units are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, 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. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or TRP, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0085] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage device, which may include a flash drive, ROM, RAM, disk, or optical disk, etc.

[0086] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A control unit for a ventricular assist device, characterized in that, The ventricular assist device includes an impeller, a motor that drives the impeller to rotate in a suspended manner, and multiple Hall sensors. The control unit is used to perform the following steps: Acquire a target pump flow rate curve and multiple target voltage curves, wherein the target pump flow rate curve is the pump flow rate curve of the ventricular assist device during operation within a first time period, and the target voltage curve is the output voltage curve of the Hall sensor within the first time period; Calculate the first feature and the second feature based on the target pumping flow rate curve and the plurality of target voltage curves; The presence of a thrombus in the ventricular assist device is determined based on the first feature and the second feature.

2. The control unit according to claim 1, characterized in that, In determining whether a thrombus exists within the ventricular assist device based on the first feature and the second feature, the control unit is specifically used for: If the first feature is greater than or equal to the first value, then it is determined that there is a thrombus in the ventricular assist device; otherwise, the second feature and the second value are compared. If the second characteristic is greater than the second value, it is determined that there is no thrombus in the ventricular assist device; otherwise, it is determined that there is a thrombus in the ventricular assist device.

3. The control unit according to claim 2, characterized in that, The control unit is also used for: Obtain the target rotation speed curve, which is the rotation speed curve of the ventricular assist device during the first time period; The third characteristic is calculated based on the multiple target voltage curves, and the fourth characteristic is calculated based on the target rotation speed curve; The location of the thrombus is determined based on the first feature, the second feature, the third feature, and the fourth feature.

4. The control unit according to claim 3, characterized in that, In determining the location of the thrombus based on the first feature, the second feature, the third feature, and the fourth feature, the control unit is specifically configured to: If the first feature is greater than the first value, then it is determined that there is a thrombus in the secondary flow channel of the ventricular assist device; If the first feature is less than or equal to the first value, the second feature is less than or equal to the second value, and the third feature is less than or equal to the third value, then it is determined that there is a thrombus at the fluid inlet of the ventricular assist device; If the first feature is less than or equal to the first value, the second feature is less than or equal to the second value, the third feature is greater than the third value, and the fourth feature is less than or equal to the fourth value, then it is determined that there is a thrombus at the fluid outlet of the ventricular assist device. If the first feature is less than or equal to the first value, the second feature is less than or equal to the second value, the third feature is greater than the third value, and the fourth feature is greater than the fourth value, then it is determined that there is a thrombus at the impeller of the ventricular assist device.

5. The control unit according to claim 3 or 4, characterized in that, In calculating the first and second characteristics based on the target pumping flow rate curve and the plurality of target voltage curves, the control unit is specifically configured to: The multiple target voltage curves are sampled according to a preset sampling frequency to obtain multiple voltage sampling points for each target voltage curve; Calculate the standard deviation of each target voltage curve based on the multiple voltage sampling points to obtain multiple first standard deviations; The average of the plurality of first standard deviations is determined as the first feature; The target flow rate is sampled from the target pumping flow rate curve according to the preset sampling frequency; The quantity of the target traffic is determined as the second feature, wherein the first derivative of the target traffic is less than a preset value.

6. The control unit according to claim 5, characterized in that, The first value, the second value, the third value, and the fourth value are determined based on the first duration and the preset sampling frequency.

7. The control unit according to claim 5, characterized in that, In calculating the third characteristic based on the plurality of target voltage curves and the fourth characteristic based on the target speed curve, the control unit is specifically configured to: The median of the plurality of first standard deviations is determined as the third feature; The target rotational speed curve is sampled according to a preset sampling frequency to obtain multiple rotational speed sampling points; The standard deviation of the plurality of rotational speed sampling points is determined as the fourth feature.

8. The control unit according to claim 4, characterized in that, The control unit is also used for: An alarm is triggered in a first manner when a thrombus is present at the fluid inlet or the impeller of the ventricular assist device. An alarm is triggered in a second manner when a thrombus is present in the secondary flow channel or the fluid outlet of the ventricular assist device.

9. A ventricular assist device, characterized in that, The ventricular assist device includes: impeller; A motor that drives the impeller to rotate in a suspended manner; Multiple Hall sensors; A control unit connected to the plurality of Hall sensors and the motor is configured to perform the following steps: Acquire a target pump flow rate curve and multiple target voltage curves, wherein the target pump flow rate curve is the pump flow rate curve of the ventricular assist device during operation within a first time period, and the target voltage curve is the output voltage curve of the Hall sensor within the first time period; Calculate the first feature and the second feature based on the target pumping flow rate curve and the plurality of target voltage curves; The presence of a thrombus in the ventricular assist device is determined based on the first feature and the second feature.

10. A medical device, characterized in that, It includes 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, the one or more programs including instructions for performing the steps performed by the control unit as described in any one of claims 1-8.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program for electronic data interchange, wherein the computer program causes a computer to perform the steps performed by the control unit as described in any one of claims 1-8.

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