Puff detection method and device

Abstract

This application proposes a method and apparatus for detecting aspiration. The method includes: acquiring a first flow rate curve and a second flow rate curve, wherein the first flow rate curve is the pumping flow rate curve of the ventricular assist device (VAD) during the first first cycle when running at a target speed, and the second flow rate curve is the pumping flow rate curve of the VAD during the second first cycle when running at the target speed; calculating a target time-domain deviation and a target frequency-domain deviation based on the first and second flow rate curves; and determining whether aspiration exists in the VAD based on the target time-domain deviation and the target frequency-domain deviation. This application improves the accuracy of aspiration detection by calculating the deviation of the VAD's pumping flow rate in the time domain and frequency domain, respectively.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a suction detection method and device. Background Technology

[0002] Currently, ventricular assist devices (VADs) have become an important means of treating end-stage heart failure. These are artificial mechanical devices that draw fluid from the venous system or heart directly into the arterial system, partially or completely replacing the work of the ventricles, thus addressing the problem of heart donor shortages. Developing suitable pump control systems to meet patients' circulatory needs, and regulating the flow rate through the VAD by controlling the pump speed, is a significant challenge arising from the increasing use of these devices. However, when the VAD's speed exceeds the user's requirements, it may cause suction problems, potentially damaging the patient's heart. Summary of the Invention

[0003] This application provides a suction detection method and apparatus that can detect in a timely and accurate manner whether there is a suction problem in the ventricular assist device.

[0004] In a first aspect, embodiments of this application provide an aspiration detection method applied to a ventricular assist device, the method comprising:

[0005] Obtain a first flow rate curve and a second flow rate curve, wherein the first flow rate curve is the pumping flow rate curve of the ventricular assist device during the first first cycle when the device is running at the target speed, and the second flow rate curve is the pumping flow rate curve of the ventricular assist device during the second first cycle when the device is running at the target speed.

[0006] Calculate the target time-domain deviation and the target frequency-domain deviation based on the first flow rate curve and the second flow rate curve;

[0007] The presence of aspiration in the ventricular assist device is determined based on the target time-domain deviation and the target frequency-domain deviation.

[0008] Secondly, 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 for:

[0009] Obtain a first flow rate curve and a second flow rate curve, wherein the first flow rate curve is the pumping flow rate curve of the ventricular assist device during the first first cycle when the device is running at the target speed, and the second flow rate curve is the pumping flow rate curve of the ventricular assist device during the second first cycle when the device is running at the target speed.

[0010] Calculate the target time-domain deviation and the target frequency-domain deviation based on the first flow rate curve and the second flow rate curve;

[0011] The presence of aspiration in the ventricular assist device is determined based on the target time-domain deviation and the target frequency-domain deviation.

[0012] Thirdly, embodiments of this application provide a ventricular assist device, characterized in that the ventricular assist device comprises:

[0013] case;

[0014] An impeller disposed within the housing;

[0015] A motor that drives the impeller to rotate in a suspended manner;

[0016] A control unit connected to the motor, the control unit being used to execute instructions for the steps in the method described in the first aspect above.

[0017] Fourthly, 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 described in the method described in the first aspect above.

[0018] Fifthly, 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 described in the method described in the first aspect above.

[0019] Sixthly, embodiments of this application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, the computer program being operable to cause a computer to perform some or all of the steps described in the method described in the first aspect of embodiments of this application. The computer program product may be a software installation package.

[0020] The technical solution provided in this application obtains a first flow rate curve and a second flow rate curve. The first flow rate curve is the pumping flow rate curve of the ventricular assist device (VAD) during the first first cycle when running at the target speed, and the second flow rate curve is the pumping flow rate curve of the VAD during the second first cycle when running at the target speed. A target time-domain deviation and a target frequency-domain deviation are calculated based on the first and second flow rate curves. The presence of aspiration in the VAD is determined based on the target time-domain deviation and the target frequency-domain deviation. This application improves the accuracy of aspiration detection by calculating the deviation of the pumping flow rate of the VAD in the time domain and frequency domain, respectively. Attached Figure Description

[0021] 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.

[0022] Figure 1 This is a schematic diagram of a ventricular assist system provided in an embodiment of this application;

[0023] Figure 2 This is a schematic diagram of the structure of a ventricular assist device provided in an embodiment of this application;

[0024] Figure 3 This is a schematic diagram of another ventricular assist system provided in an embodiment of this application;

[0025] Figure 4 This is a schematic flowchart of a suction detection method provided in an embodiment of this application;

[0026] Figure 5 This application provides a mapping table of slurring probabilities in the time and frequency domains.

[0027] Figure 6 This is a schematic diagram of the structure of a medical device provided in an embodiment of this application. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] 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.

[0031] The medical device involved in this application may be a ventricular assist device, such as an implantable ventricular assist device. This ventricular assist device can be used for the left ventricle, right ventricle, or both. The ventricular assist device may include at least one blood pump, which may be a magnetically levitated pump.

[0032] In this application, "rotational speed" refers to the speed of rotation of a motor or electric motor, which is related to the speed of rotation of the rotor or impeller of the ventricular assist device and can be defined as rotational speed per minute. "Flow rate," "fluid flow rate," and "pump flow rate" refer to the volume of fluid delivered through the ventricular assist device per unit time, which can be estimated and measured in liters per minute.

[0033] Patients with heart failure can have a ventricular assist device implanted to help their heart pump blood. A ventricular assist device can be placed in the left ventricle to pump blood from the left ventricle to the aorta, addressing left heart failure; or it can be placed in the right ventricle to pump blood from the right ventricle to the pulmonary artery, addressing right heart failure.

[0034] The ventricular assist system of this application may include LVAD (left ventricular assist device), RVAD (right ventricular assist device), or BIVAD (biventricular assist device). These systems include not only a ventricular assist device implanted in the patient during operation, but also typically a controller disposed outside the patient and connected to the ventricular assist device via a percutaneous wire (drive system). A portion of the drive system extends outside the patient between the controller and the puncture site, while another portion extends inside the patient between the puncture site and the ventricular assist device. The controller may include, for example, an integrated rechargeable battery or may be connected to a battery such that the implanted ventricular assist device is powered by the controller via a line through the skin. The ventricular assist device typically includes a motor having a stator and a rotor having blades. The motor of the ventricular assist device can typically be driven by power supplied by the controller, for example, by generating current in the windings of the stator, which causes the rotor and its blades to rotate in order to deliver the patient's blood.

[0035] Please see Figure 1 , Figure 1This application provides a ventricular assist system. The ventricular assist system includes a ventricular assist device 100 and a controller 200, and a percutaneous cable 300 connecting the ventricular assist device 100 to the controller 200. The proximal end of the percutaneous cable 300 extends through the skin into the ventricular assist device 100 to transmit electrical power, information, and control signals for the operation of the ventricular assist device 100.

[0036] The ventricular assist device 100 can be implanted in the body, for example, it can be attached to the heart via a ventricular connection component (such as a top ring, ventricular cuff, or ventricular linker), which can be sutured to the heart and connected to the ventricular assist device 100. The other end of the ventricular assist device 100 can be connected to the ascending aorta or pulmonary artery via an outlet tube and / or an artificial blood vessel connected to the outlet tube. This allows the ventricular assist device 100 to effectively transfer blood from the weakened ventricle and propel it into the aorta or pulmonary artery, thereby circulating it to the rest of the patient's vascular system and providing ventricular assist function to the patient.

[0037] The controller 200 is used to monitor the ventricular assist device 100, and can control and display the ventricular assist device 100, as well as perform functions such as fault detection, alarm, and data logging. For example, the controller 200 may have a touchscreen display for displaying the operating data of the ventricular assist device 100, patient information, and other information about the ventricular assist device 100. Furthermore, the user can set the operating parameters of the ventricular assist device 100 through the controller 200.

[0038] Please see Figure 2 , Figure 2 This is a schematic diagram of a ventricular assist device 100 according to an embodiment of this application. The ventricular assist device 100 includes a housing assembly with an inlet pipe 50, an impeller 20 for propelling fluid, and a motor 30 for driving the impeller 20 to levitate and rotate. The housing assembly includes a first housing and a second housing connected to the first housing. The first housing and the second housing together form a chamber 10. The housing assembly also has a fluid inlet 14 and a fluid outlet 15 communicating with the chamber 10, and the fluid inlet 14 is located on the first housing. The impeller 20 can levitate and rotate 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 levitation and rotation of the impeller 20 means that the impeller 20 does not contact the chamber wall of the chamber 10 during rotation.

[0039] The second housing includes a first sidewall 11, and the first housing includes a second sidewall 12. The motor 30 includes a stator 31 and a rotor 32 arranged on both sides 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 with the rotor 32 within the chamber 10.

[0040] The ventricular assist device 100 also includes a control unit 33, which is electrically connected to the stator 31. The control unit 33 can control the rotational speed and levitation height of the rotor 32 by adjusting the current flowing through the stator 31.

[0041] Please see Figure 3 , Figure 3 This is a schematic diagram of another ventricular assist system provided in an embodiment of this application. The ventricular assist system includes a left ventricular assist device 210, a right ventricular assist device 220, a controller 230, and a percutaneous cable 240. The left ventricular assist device 210 and the right ventricular assist device 220 are implanted in the body, while the controller 230 is disposed externally and connected to the left ventricular assist device 210 and the right ventricular assist device 220 via the percutaneous cable 240.

[0042] The structures of the left ventricular assist device 210 and the right ventricular assist device 220 are similar to those of the left ventricular assist device 210 and the right ventricular assist device 220. Figure 1 The structure of the ventricular assist device 100 is the same as that of the ventricular assist device 100, and will not be described in detail here.

[0043] The inlet tube 50 is fixed at the apex of the left ventricle. During the implantation or operation of the ventricular assist device 100, left ventricular assist device 210, or right ventricular assist device 220, the inlet tube 50 may become too close to or adjacent to cardiac tissue, leading to aspiration events. Aspiration events may also occur when the fluid inlet 14 interacts with cardiac tissue, causing partial or complete blockage of the inlet tube 50. Sustained aspiration may damage the patient's heart, impair the function of the ventricular assist device system, and lead to insufficient perfusion.

[0044] Based on this, this application proposes a suction detection method, which calculates the changes in pumping flow rate of the ventricular assist device in the time domain and frequency domain respectively, and determines whether suction has occurred in the ventricular assist device based on the changes in pumping flow rate in the time domain and frequency domain, thereby improving the accuracy of suction detection.

[0045] Based on the above description, this application will now be described from the perspective of method examples.

[0046] Please see Figure 4 , Figure 4 This is a schematic flowchart of a suction detection method provided in an embodiment of this application, which is applied to, for example... Figure 1 The ventricular assist device shown. (Example) Figure 4 As shown, the method includes the following steps.

[0047] S410. Obtain a first flow rate curve and a second flow rate curve, wherein the first flow rate curve is the pumping flow rate curve of the ventricular assist device during the first first cycle when the device is running at the target speed, and the second flow rate curve is the pumping flow rate curve of the ventricular assist device during the second first cycle when the device is running at the target speed.

[0048] During operation of the ventricular assist device 100 within the user's body, the pumping flow rate through the ventricular assist device 100 depends on the work that the ventricular assist device 100 must do to overcome resistance and 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 required to supply the motor 30; that is, the motor current corresponds to the amount of current delivered to the motor 30 when the ventricular assist device 100 is operating within the user. The load on the motor 30 varies during different phases of the user's cardiac cycle. When the pressure differential in the user's heart changes, the motor current also changes to maintain a constant rotor 32 speed. For example, when the rate of blood flow into the aorta 124 increases (such as during cardiac contraction), the current required by the motor will increase. Therefore, changes in the motor current can thus help characterize cardiac performance. In other words, during the operation of the ventricular assist device 100, the ventricular assist device 100 has a current-flow characteristic curve, in which 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.

[0049] 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). This current-flow characteristic curve can be pre-stored in the control unit 33. Before the ventricular assist device 100 leaves the factory, it can be placed in a testing system to test the relationship between the pumping flow rate and current at different speeds, and then the current-flow characteristic curve can be stored in the control unit 33. The control unit 33 can store the detected current in real time.

[0050] When the ventricular assist device 100 is running at the target speed, the control unit 33 acquires the current curve, estimates the flow curve corresponding to the current curve using the pre-stored current-flow characteristic curve, and then collects the pumping flow of the ventricular assist device 100 from the flow curve according to the sampling frequency.

[0051] After the ventricular assist device 100 is implanted in the patient, the control unit 33 collects the pump flow rate in each first cycle as a set of data. By comparing the changes in two adjacent sets of pump flow rate data, it can be determined whether aspiration has occurred in the ventricular assist device. Specifically, the control unit 33 uses the pump flow rate curve in the first first cycle as the first flow rate curve and the pump flow rate curve in the next first cycle as the second flow rate curve.

[0052] The first cycle can be set according to the patient's condition; for example, the more severe the patient's heart failure, the shorter the first cycle should be. The first cycle can also be set according to the patient's hemodynamic parameters, such as 10s, 20s, 30s, etc.

[0053] S420. Calculate the target time domain deviation and the target frequency domain deviation based on the first flow rate curve and the second flow rate curve.

[0054] The target time-domain deviation is the deviation of the pumping flow rate curve of the ventricular assist device 100 between adjacent first cycles in the time domain, and the target frequency-domain deviation is the deviation of the pumping flow rate curve of the ventricular assist device 100 between adjacent first cycles in the frequency domain.

[0055] Aortic regurgitation, abnormal position of the ventricular assist device 100 (VAM), abnormal patient heart rate, aspiration of the VAM, and abnormal VAM rotation speed (too high or too low) can all cause abnormalities in the pumping flow rate of the VAM in the time domain. Judging whether aspiration is occurring solely based on time-domain anomalies in the pumping flow rate curve is highly inaccurate. When aspiration occurs, the minimum pumping flow rate in the VAM's pumping flow rate curve will decrease sharply, and a small pulsating peak may appear between the minimum and maximum pumping flow rates. This small pulsating peak will appear as a small pulse in the frequency domain. Therefore, when there are significant deviations in both the time and frequency domains of the pumping flow rate curves in adjacent first cycles, the probability of aspiration in the current VAM is considered high.

[0056] Optionally, the step of calculating the target time-domain deviation and the target frequency-domain deviation based on the first flow curve and the second flow curve includes: calculating a first flow difference based on the first flow curve and a second flow difference based on the second flow curve; performing spectral analysis on the first flow curve and the second flow curve respectively to obtain a first spectrum and a second spectrum; calculating the proportion of the energy of the fundamental component frequency band to the total energy in the first spectrum and the second spectrum respectively to obtain a first proportion and a second proportion; using the difference between the second flow difference and the first flow difference as the target time-domain deviation, and using the difference between the first proportion and the second proportion as the target frequency-domain deviation.

[0057] When the ventricular assist device 100 is operating normally, the waveform of its pumping flow rate in the time domain is generally a sine wave. When the ventricular assist device 100 performs suction, the minimum pumping flow rate in its pumping flow rate curve in the time domain will decrease sharply, and a small pulsating peak may also be generated between the minimum and maximum pumping flow rates; while in the frequency domain, the amplitude of the fundamental component corresponding to its sine wave will decrease, and the harmonic component corresponding to the pulsating peak will be added to the spectrum, thereby reducing the proportion of the energy of the fundamental frequency band in the entire spectrum.

[0058] The step of calculating the first flow difference based on the first flow curve and the second flow difference based on the second flow curve includes: obtaining a first pumping flow rate and a second pumping flow rate from the first flow curve, wherein the first pumping flow rate is the maximum pumping flow rate in the first flow curve and the second pumping flow rate is the minimum pumping flow rate in the first flow curve; obtaining a third pumping flow rate and a fourth pumping flow rate from the second flow curve, wherein the third pumping flow rate is the maximum pumping flow rate in the second flow curve and the fourth pumping flow rate is the minimum pumping flow rate in the second flow curve; calculating a first average flow rate and a second average flow rate, wherein the first average flow rate is the average flow rate of the first flow curve and the second average flow rate is the average flow rate of the second flow curve; substituting the first pumping flow rate, the second pumping flow rate, and the first average flow rate into the target formula to calculate the first flow difference, and substituting the third pumping flow rate, the fourth pumping flow rate, and the second average flow rate into the target formula to calculate the second flow difference.

[0059] The target formula is: Q = (q ave -q min )-(q max -q ave ), where qave is the average pumping flow rate, qmin is the minimum pumping flow rate, and q ave This is the maximum pumping flow rate.

[0060] Specifically, after the control unit 33 obtains the pumping flow rate of the ventricular auxiliary device 100 in the first cycle according to the sampling frequency, it calculates the average flow rate q1 in the first cycle. ave The first average flow rate is used, and the maximum pumping flow rate q1 within this first period is taken as the first average flow rate. max and minimum pumping flow rate q1 min The first and second pumping flow rates are respectively used as the first pumping flow rate and the second pumping flow rate. Then, these are substituted into the target formula to calculate the first flow difference Q1 = (q1 ave -q1 min )-(q1 max -q1 aveSimilarly, for the next first cycle, after the control unit obtains the pumping flow rate of the ventricular auxiliary device 100 according to the sampling frequency, it calculates the average flow rate q2 within that first cycle. ave As the third average flow rate, and the maximum pumping flow rate q2 within the first cycle. max and minimum pumping flow rate q2 min The third and fourth pumping flow rates are respectively used as the third and fourth pumping flow rates, and then substituted into the target formula to calculate the second flow difference Q2 = (q2 ave -q2 min )-(q2 max -q2 ave Finally, the difference Q2-Q1 between the second flow rate difference and the first flow rate difference is taken as the target time domain deviation.

[0061] When judging the pump flow rate curve in the time domain of the ventricular assist device 100, the control unit will also perform a Fourier transform on the pump flow rate curve in each first cycle, transforming the pump flow rate curve in the time domain into a spectrum in the frequency domain. Then, spectral analysis is performed on each spectrum to obtain the total energy and the energy of the fundamental component frequency band of each spectrum. Specifically: the control unit performs spectral analysis on the first spectrum of the pump flow rate curve transformation in the first first cycle, and takes the ratio F1 of the energy of the fundamental component frequency band in the first spectrum to the total energy as the first proportion; it performs spectral analysis on the second spectrum of the pump flow rate curve transformation in the second first cycle, and takes the ratio F2 of the energy of the fundamental component frequency band in the second spectrum to the total energy as the second proportion. Then, the difference between the first proportion and the second proportion, F1-F2, is taken as the target frequency domain deviation.

[0062] S430. Determine whether the ventricular assist device is aspirating based on the target time domain deviation and the target frequency domain deviation.

[0063] In this application, the control unit 33 jointly determines the probability of aspiration occurring in the ventricular assist device 100 based on the deviation between the pumping flow rate of the ventricular assist device 100 in the time domain and frequency domain and the normal pumping flow rate, which can greatly improve the accuracy of aspiration detection.

[0064] For example, determining whether the ventricular assist device (VAM) has aspiration based on the target time-domain deviation and the target frequency-domain deviation includes: determining a first aspiration probability based on the target time-domain deviation, where the first aspiration probability is the probability that the VAM will aspirate in the time domain; determining a second aspiration probability based on the target frequency deviation, where the second aspiration probability is the probability that the VAM will aspirate in the frequency domain; determining the target aspiration probabilities corresponding to the first and second aspiration probabilities from a target mapping table; and determining whether the VAM has aspiration based on the target aspiration probabilities.

[0065] The control unit 33 determines the probability of ventricular assist device 100 aspiration in the time domain based on the magnitude of the target time domain deviation, and determines the probability of ventricular assist device 100 aspiration in the frequency domain based on the magnitude of the target frequency domain deviation. Finally, based on the probability of aspiration in the time domain and the probability of aspiration in the frequency domain, it determines whether ventricular assist device 100 aspiration occurs.

[0066] Optionally, determining the first aspiration probability based on the target time-domain deviation includes: if the target time-domain deviation is less than or equal to a first value, determining the first aspiration probability to be zero; if the target time-domain deviation is greater than the first value and less than or equal to a second value, determining the first aspiration probability to be low; if the target time-domain deviation is greater than the second value and less than a third value, determining the first aspiration probability to be medium; and if the target time-domain deviation is greater than or equal to the third value, determining the first aspiration probability to be high.

[0067] Specifically, if the target time-domain deviation Q2-Q1 is greater than or equal to the third value, it is considered that the deviation between the pumping flow rate curve in the second first cycle and the pumping flow rate curve in the first first cycle is large, and the probability of suction is high; if the target time-domain deviation Q2-Q1 is less than the third value and greater than the second value, it is considered that the deviation between the pumping flow rate curve in the second first cycle and the pumping flow rate curve in the first first cycle is small, and the probability of suction is medium; if the target time-domain deviation Q2-Q1 is less than or equal to the second value and greater than the first value, it is considered that the deviation between the pumping flow rate curve in the second first cycle and the pumping flow rate curve in the first first cycle is small, and the probability of suction is low; if the target time-domain deviation Q2-Q1 is equal to the first value, it is considered that there is no deviation between the pumping flow rate curve in the second first cycle and the pumping flow rate curve in the first first cycle, and there is no possibility of suction.

[0068] Wherein, the first value is -k times the second average flow rate, where k is greater than 0 and less than 1, the third value is k times the second average flow rate, and the second value is 0. For example, k can take values ​​of 1 / 2, 1 / 3, 1 / 4, 1 / 5, etc. During aspiration, the fluctuation of the ventricular assist device's pumping flow rate in the time domain increases. Therefore, when the target time domain deviation is less than or equal to -k times the second average flow rate, it indicates that the fluctuation of the pumping flow rate in the second first cycle is less than the fluctuation of the pumping flow rate in the first first cycle, and at this time, there is no possibility of aspiration occurring with the ventricular assist device.

[0069] Optionally, determining the second suction probability based on the target frequency deviation includes: if the target frequency deviation is equal to the second value, then determining the second suction probability to be zero; if the target frequency deviation is greater than the second value and less than the fourth value, then determining the second suction probability to be low; if the target frequency deviation is greater than or equal to the fourth value, then determining the second suction probability to be high.

[0070] Specifically, if the target frequency domain deviation F1-F2 is greater than or equal to the fourth value, it is considered that the deviation between the spectrum of the pumping flow rate curve in the second first cycle and the spectrum of the pumping flow rate curve in the first first cycle is large, and the probability of suction is high; if the target frequency domain deviation F1-F2 is less than the fourth value but greater than the second value, it is considered that the deviation between the spectrum of the pumping flow rate curve in the second first cycle and the spectrum of the pumping flow rate curve in the first first cycle is small, and the probability of suction is low; if the target frequency domain deviation F1-F2 is less than or equal to the second value, it is considered that there is no deviation between the spectrum of the pumping flow rate curve in the second first cycle and the spectrum of the pumping flow rate curve in the first first cycle, and the probability of suction is 0.

[0071] The fourth value is m times the second proportion, where m is greater than 0 and less than 1. For example, m can take values ​​of 1 / 5, 1 / 7, 1 / 8, 1 / 10, etc.

[0072] After obtaining the probabilities of aspiration occurring in the ventricular assist device 100 in the time and frequency domains, the control unit determines the aspiration probability of the ventricular assist device 100 according to a pre-stored target mapping table. The target mapping table is as follows: Figure 5As shown, when the aspiration probability in the time domain is zero and the aspiration probability in the frequency domain is zero, the probability of aspiration occurring in the ventricular assist device 100 is zero; when the aspiration probability in the time domain is zero and the aspiration probability in the frequency domain is low, the probability of aspiration occurring in the ventricular assist device 100 is low; when the aspiration probability in the time domain is zero and the aspiration probability in the frequency domain is high, the probability of aspiration occurring in the ventricular assist device 100 is low; when the aspiration probability in the time domain is low and the aspiration probability in the frequency domain is zero, the probability of aspiration occurring in the ventricular assist device 100 is zero; when the aspiration probability in the time domain is low and the aspiration probability in the frequency domain is low, the probability of aspiration occurring in the ventricular assist device 100 is low; when the aspiration probability in the time domain is low and the aspiration probability in the frequency domain is high, the probability of aspiration occurring in the ventricular assist device 100 is... When the aspiration probability in the time domain is medium and the aspiration probability in the frequency domain is zero, the probability of aspiration occurring in the ventricular assist device 100 is low; when the aspiration probability in the time domain is medium and the aspiration probability in the frequency domain is medium, the probability of aspiration occurring in the ventricular assist device 100 is medium; when the aspiration probability in the time domain is medium and the aspiration probability in the frequency domain is high, the probability of aspiration occurring in the ventricular assist device 100 is high; when the aspiration probability in the time domain is high and the aspiration probability in the frequency domain is zero, the probability of aspiration occurring in the ventricular assist device 100 is medium; when the aspiration probability in the time domain is high and the aspiration probability in the frequency domain is low, the probability of aspiration occurring in the ventricular assist device 100 is high; when the aspiration probability in the time domain is high and the aspiration probability in the frequency domain is high, the probability of aspiration occurring in the ventricular assist device 100 is high.

[0073] The control unit determines the probability of aspiration occurring in the second first cycle of the ventricular assist device 100 based on the target mapping table. Based on the above method, the control unit determines the probability of aspiration occurring in the subsequent third, fourth, and i-th first cycles. If the probability of aspiration occurring in a particular first cycle is high, an aspiration alarm is triggered to alert the user or medical staff of the potential for aspiration.

[0074] In one possible example, the method further includes: recording a first quantity and a second quantity of ventricular assist devices in n first cycles, wherein the first quantity is the quantity with a high aspiration probability and the second quantity is the quantity with a heavy aspiration probability; obtaining an aspiration alarm mode; determining an alarm threshold according to the aspiration alarm mode; and triggering an aspiration alarm based on the first quantity, the second quantity, and the alarm threshold.

[0075] The suction alarm method may include a high alarm mode, a medium alarm mode, and a low alarm mode. The alarm threshold for the high alarm mode is that a first quantity is greater than a first value; the alarm threshold for the medium alarm mode is that a first quantity is greater than the first value, and a second quantity is greater than a second value, and the second value is greater than the first value; the alarm threshold for the low alarm mode is that a first quantity is greater than a second value.

[0076] The first value can be 5, 8, 10, etc., and the second value can be 15, 20, 25, etc. n can be 30, 60, 90, 120, etc.

[0077] For example, the pumping flow rate of the control unit within 5 minutes is divided into 30 first cycles of 10 seconds each. Then, the aspiration probability of the ventricular assist device 100 is calculated for each of these 30 first cycles using the method described above. If a high alarm mode is used, if the number of times the ventricular assist device 100 has a high aspiration probability is greater than 10, an aspiration alarm is recorded and displayed; otherwise, no aspiration alarm is triggered. If a medium alarm mode is used, if the number of times the ventricular assist device 100 has a high aspiration probability is greater than 10 and the number of times it has a medium aspiration probability is greater than 20, an aspiration alarm is recorded and displayed; otherwise, no aspiration alarm is triggered. If a low alarm mode is used, if the number of times the ventricular assist device 100 has a high aspiration probability is greater than 20, an aspiration alarm is recorded and displayed; otherwise, no aspiration alarm is triggered.

[0078] Furthermore, if three consecutive suction alarms occur, the control unit can gradually reduce the speed of the ventricular assist device 100 by 100 rpm every 5 minutes until no suction alarms occur or the speed of the ventricular assist device 100 exceeds the allowable speed range, at which point the speed is restored.

[0079] As can be seen, this application proposes a suction detection method, which acquires a first flow rate curve and a second flow rate curve. The first flow rate curve is the pumping flow rate curve of the ventricular assist device (VAD) during the first first cycle when running at the target speed, and the second flow rate curve is the pumping flow rate curve of the VAD during the second first cycle when running at the target speed. A target time-domain deviation and a target frequency-domain deviation are calculated based on the first and second flow rate curves. The presence of suction in the VAD is determined based on the target time-domain deviation and the target frequency-domain deviation. This application improves the accuracy of suction detection by calculating the deviation of the VAD's pumping flow rate in the time domain and frequency domain, respectively.

[0080] 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.

[0081] For example, this application provides a control unit for a ventricular assist device, the control unit including one or more processors, the one or more processors being configured to: acquire a first flow rate curve and a second flow rate curve, the first flow rate curve being the pumping flow rate curve of the ventricular assist device during a first first cycle when the ventricular assist device is running at a target rotational speed, and the second flow rate curve being the pumping flow rate curve of the ventricular assist device during a second first cycle when the ventricular assist device is running at the target rotational speed; calculate a target time domain deviation and a target frequency domain deviation based on the first flow rate curve and the second flow rate curve; and determine whether the ventricular assist device is aspirating based on the target time domain deviation and the target frequency domain deviation.

[0082] For example, this application also provides a ventricular assist device, characterized in that the ventricular assist device includes:

[0083] case;

[0084] An impeller disposed within the housing;

[0085] A motor that drives the impeller to rotate in a suspended manner;

[0086] A control unit connected to the motor, the control unit being used in some or all of the steps described in the method described above.

[0087] For example, this application also provides a medical device that includes the control device or ventricular assist device described above.

[0088] The control devices of the above-mentioned schemes have the function of implementing the corresponding steps performed by the medical device in the above-mentioned methods; the function can be implemented by hardware or by hardware executing corresponding software.

[0089] In embodiments of this application, the control device may also be a chip or a chip system, such as a system on chip (SoC).

[0090] Please see Figure 6 , Figure 6 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.

[0091] The above procedure includes instructions for performing the following steps:

[0092] Obtain a first flow rate curve and a second flow rate curve, wherein the first flow rate curve is the pumping flow rate curve of the ventricular assist device during the first first cycle when the device is running at the target speed, and the second flow rate curve is the pumping flow rate curve of the ventricular assist device during the second first cycle when the device is running at the target speed.

[0093] Calculate the target time-domain deviation and the target frequency-domain deviation based on the first flow rate curve and the second flow rate curve;

[0094] The presence of aspiration in the ventricular assist device is determined based on the target time-domain deviation and the target frequency-domain deviation.

[0095] 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.

[0096] 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.

[0097] In the embodiments of this application, the processor of the above-described device may be a Central Processing Unit (CPU), which may also 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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 flash drives, ROM, RAM, magnetic disks, or optical disks, etc.

[0110] 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 suction detection method, characterized in that, Applied to ventricular assist devices, the method includes: Obtain a first flow rate curve and a second flow rate curve, wherein the first flow rate curve is the pumping flow rate curve of the ventricular assist device during the first first cycle when the device is running at the target speed, and the second flow rate curve is the pumping flow rate curve of the ventricular assist device during the second first cycle when the device is running at the target speed. The target time domain deviation and the target frequency domain deviation are calculated based on the first flow curve and the second flow curve. The target time domain deviation is the deviation of the pumping flow curve of the ventricular assist device between adjacent first cycles in the time domain, and the target frequency domain deviation is the deviation of the pumping flow curve of the ventricular assist device between adjacent first cycles in the frequency domain. The presence of aspiration in the ventricular assist device is determined based on the target time-domain deviation and the target frequency-domain deviation.

2. The method according to claim 1, characterized in that, The step of calculating the target time-domain deviation and the target frequency-domain deviation based on the first flow rate curve and the second flow rate curve includes: Calculate the first flow difference based on the first flow curve, and calculate the second flow difference based on the second flow curve; Spectral analysis was performed on the first flow curve and the second flow curve to obtain the first spectrum and the second spectrum; Calculate the ratio of the energy of the fundamental component frequency band to the total energy in the first spectrum and the second spectrum respectively to obtain the first ratio and the second ratio; The difference between the second flow rate difference and the first flow rate difference is taken as the target time domain deviation, and the difference between the first proportion and the second proportion is taken as the target frequency domain deviation.

3. The method according to claim 2, characterized in that, The step of calculating the first flow difference based on the first flow curve and the second flow difference based on the second flow curve includes: The first pumping flow rate and the second pumping flow rate are obtained from the first flow rate curve, wherein the first pumping flow rate is the maximum pumping flow rate in the first flow rate curve, and the second pumping flow rate is the minimum pumping flow rate in the first flow rate curve; The third pumping flow rate and the fourth pumping flow rate are obtained from the second flow rate curve, wherein the third pumping flow rate is the maximum pumping flow rate in the second flow rate curve and the fourth pumping flow rate is the minimum pumping flow rate in the second flow rate curve; Calculate the first average flow rate and the second average flow rate respectively. The first average flow rate is the average flow rate of the first flow rate curve, and the second average flow rate is the average flow rate of the second flow rate curve. The first flow rate difference is calculated by substituting the first pumping flow rate, the second pumping flow rate, and the first average flow rate into the target formula, and the second flow rate difference is calculated by substituting the third pumping flow rate, the fourth pumping flow rate, and the second average flow rate into the target formula.

4. The method according to claim 3, characterized in that, The target formula is: , wherein For the average pumping flow rate, the For the minimum pumping flow rate, the This is the maximum pumping flow rate.

5. The method according to claim 3, characterized in that, The step of determining whether the ventricular assist device has aspiration based on the target time domain deviation and the target frequency domain deviation includes: The first aspiration probability is determined based on the target time domain deviation, and the first aspiration probability is the probability that the ventricular assist device will aspirate in the time domain; The second aspiration probability is determined based on the target frequency domain deviation, and the second aspiration probability is the probability that the ventricular assist device will aspirate in the frequency domain. Determine the target suction probabilities corresponding to the first suction probability and the second suction probability from the target mapping table; The presence of aspiration in the ventricular assist device is determined based on the target aspiration probability.

6. The method according to claim 5, characterized in that, Determining the first aspiration probability based on the target time-domain deviation includes: If the target time-domain deviation is less than or equal to the first value, then the first suction probability is determined to be zero. If the target time-domain deviation is greater than the first value and less than or equal to the second value, then the first aspiration probability is determined to be low. If the target time-domain deviation is greater than the second value and less than the third value, then the first suction probability is determined to be medium. If the target time-domain deviation is greater than or equal to the third value, then the first suction probability is determined to be high.

7. The method according to claim 6, characterized in that, The step of determining the second pumping probability based on the target frequency domain deviation includes: If the target frequency domain deviation is equal to the second value, then the second pumping probability is determined to be zero. If the target frequency domain deviation is greater than the second value and less than the fourth value, then the second pumping probability is determined to be low. If the target frequency domain deviation is greater than or equal to the fourth value, then the second pumping probability is determined to be high.

8. The method according to claim 6, characterized in that, The first value is -k times the second average flow rate, where k is greater than 0 and less than 1, and the third value is k times the second average flow rate, while the second value is 0.

9. The method according to claim 7, characterized in that, The fourth value is m times the second proportion, where m is greater than 0 and less than 1.

10. A control unit for a ventricular assist device, characterized in that, The control unit includes one or more processors, the one or more processors being used for: Obtain a first flow rate curve and a second flow rate curve, wherein the first flow rate curve is the pumping flow rate curve of the ventricular assist device during the first first cycle when the device is running at the target speed, and the second flow rate curve is the pumping flow rate curve of the ventricular assist device during the second first cycle when the device is running at the target speed. The target time domain deviation and the target frequency domain deviation are calculated based on the first flow curve and the second flow curve. The target time domain deviation is the deviation of the pumping flow curve of the ventricular assist device between adjacent first cycles in the time domain, and the target frequency domain deviation is the deviation of the pumping flow curve of the ventricular assist device between adjacent first cycles in the frequency domain. The presence of aspiration in the ventricular assist device is determined based on the target time-domain deviation and the target frequency-domain deviation.

11. A ventricular assist device, characterized in that, The ventricular assist device includes: case; An impeller disposed within the housing; A motor that drives the impeller to rotate in a suspended manner; A control unit connected to the motor, the control unit being configured to execute instructions for the steps of the method as described in any one of claims 1-9.

12. A medical device, characterized in that, The device includes a processor, a memory, and a communication interface. The memory stores one or more programs, which are executed by the processor. The one or more programs include instructions for performing the steps of the method as described in any one of claims 1-9.

13. 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 of the method as described in any one of claims 1-9.

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