Suction detection method and device

Abstract

The invention provides a suction detection method and device.The method comprises the steps that a first flow curve and a second flow curve are obtained, the first flow curve is a pumping flow curve of a ventricular assist device in a first period when the ventricular assist device operates at a target rotating speed, and the second flow curve is a pumping flow curve of the ventricular assist device in a second period; the second flow curve is a pumping flow curve of the ventricular assist device in a second first period when the ventricular assist device operates at the target rotating speed; calculating a target time domain deviation and a target frequency domain deviation according to the first flow curve and the second flow curve; according to the target time domain deviation and the target frequency domain deviation, whether the ventricular assist device sucks or not is judged. According to the method, the deviation of the pumping flow of the ventricular assist device is calculated in the time domain and the frequency respectively, so that whether the ventricular assist device sucks or not is detected, and the accuracy of suction detection is improved.

Description

Technical Field

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

[0002] At present, ventricular assist device (VAD) has become an important means of treating end-stage heart failure. It is an artificial mechanical device that draws fluid from the venous system or heart directly into the arterial system, partially or completely replacing the work of the ventricles, and can solve the problem of shortage of heart donors. In order to meet the circulation needs of patients, developing a suitable pump control system to regulate the pumping flow through the ventricular assist device by controlling the speed of the pump is an important challenge faced by the increased use of these devices. However, when the speed of the ventricular assist device exceeds the user's requirements, it may cause suction problems in the ventricular assist device and damage the patient's heart. Summary of the invention

[0003] The embodiments of the present application provide a suction detection method and device, which can timely and accurately detect whether there is a suction problem in a ventricular assist device.

[0004] In a first aspect, an embodiment of the present application provides a suction detection method, which is applied to a ventricular assist device, and the method includes:

[0005] Acquire a first flow curve and a second flow curve, wherein the first flow curve is a pumping flow curve in a first first cycle when the ventricular assist device operates at a target speed, and the second flow curve is a pumping flow curve in a second first cycle when the ventricular assist device operates at the target speed;

[0006] Calculating a target time domain deviation and a target frequency domain deviation according to the first flow curve and the second flow curve;

[0007] It is determined whether the ventricular assist device is pumping based on the target time domain deviation and the target frequency domain deviation.

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

[0009] Acquire a first flow curve and a second flow curve, wherein the first flow curve is a pumping flow curve in a first first cycle when the ventricular assist device operates at a target speed, and the second flow curve is a pumping flow curve in a second first cycle when the ventricular assist device operates at the target speed;

[0010] Calculating a target time domain deviation and a target frequency domain deviation according to the first flow curve and the second flow curve;

[0011] It is determined whether the ventricular assist device is pumping based on the target time domain deviation and the target frequency domain deviation.

[0012] In a third aspect, an embodiment of the present application provides a ventricular assist device, characterized in that the ventricular assist device comprises:

[0013] case;

[0014] an impeller disposed in the housing;

[0015] A motor driving the impeller to rotate in suspension;

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

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

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

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

[0020] The technical solution provided by the present application obtains a first flow curve and a second flow curve, wherein the first flow curve is a pumping flow curve of the ventricular assist device in the first first cycle when the ventricular assist device is running at a target speed, and the second flow curve is a pumping flow curve of the ventricular assist device in the second first cycle when the ventricular assist device is running at a target speed; calculates a target time domain deviation and a target frequency domain deviation based on the first flow curve and the second flow curve; and determines whether the ventricular assist device has suction based on the target time domain deviation and the target frequency domain deviation. The present application improves the accuracy of suction detection by calculating the deviation of the pumping flow of the ventricular assist device in the time domain and frequency respectively to detect whether the ventricular assist device has suction. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

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

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

[0025] Figure 4 It is a flow chart of a suction detection method provided in an embodiment of the present application;

[0026] Figure 5 It is a mapping table of puff probability in the time domain and frequency domain provided in an embodiment of the present application;

[0027] Figure 6 It is a structural schematic diagram of a medical device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to help those skilled in the art better understand the technical solutions of the present application, the following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the description of the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0029] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, software, product, or device that includes a series of steps or units is not limited to the listed steps or units, but also includes steps or units that are not listed, or also includes other steps or units inherent to these processes, methods, products, or devices.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] The medical device involved in the present application may be a ventricular assist device, such as an implantable ventricular assist device. The ventricular assist device may be used for the left heart, the right heart, or both hearts. The ventricular assist device may include at least one blood pump, which may be a magnetic levitation pump.

[0032] "Speed" as used herein refers to the rotational speed of a motor or electric machine, which is associated with the rotational speed of the rotor or impeller of a ventricular assist device, and may be defined as revolutions per minute. "Flow", "fluid flow", "pumping flow" refers to the volume of fluid delivered through the ventricular assist device per unit of time, which may be measured in liters per minute.

[0033] Patients with heart failure can use a ventricular assist device to assist the heart in completing its pumping function. The ventricular assist device can be placed in the patient's left ventricle to pump blood from the patient's left ventricle to the aorta to solve the patient's left heart failure problem; the ventricular assist device can also be placed in the patient's right ventricle to pump blood from the patient's right ventricle to the pulmonary artery to solve the patient's right heart failure problem.

[0034] The ventricular assist system of the present application may include an LVAD (left ventricular assist device), an RVAD (right ventricular assist device) or a BIVAD (biventricular assist device), which include not only a ventricular assist device implanted in the patient's body during operation, but also typically include a controller disposed outside the patient's body and connected to the ventricular assist device via a percutaneous line (transmission system). A portion of the transmission system extends outside the patient's body between the controller and the puncture site, while another portion extends into the patient's body between the puncture site and the ventricular assist device. The controller may, for example, include an integrated battery (rechargeable battery) or may be connected to a battery so that the implanted ventricular assist device may be powered by the controller via a percutaneous line. The ventricular assist device typically includes a motor having a stator and a rotor having blades. The motor of the ventricular assist device may typically be driven by power delivered by the controller, for example, 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] See also Figure 1 , Figure 1A ventricular assist system is provided in an embodiment of the present application. The ventricular assist system includes a ventricular assist device 100, a controller 200, and a percutaneous cable 300 for 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 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, a ventricular cuff, or a ventricular cuff), 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 the pulmonary artery via an outlet tube and / or an artificial blood vessel connected to the outlet tube, so that the ventricular assist device 100 can effectively transfer blood from the weakened ventricle and propel it to the aorta or the pulmonary artery, thereby circulating it to the rest of the patient's vascular system and providing ventricular assist function for the patient.

[0037] The controller 200 is used to monitor the ventricular assist device 100, and can realize functions such as control and data display of the ventricular assist device 100, fault detection, alarm, and data recording. For example, the controller 200 may have a touch screen display for displaying the operating data of the ventricular assist device 100, patient information, information of the ventricular assist device 100, etc. Further, the user can set the operating parameters of the ventricular assist device 100 through the controller 200.

[0038] See also Figure 2 , Figure 2 : is a schematic diagram of the structure of a ventricular assist device 100 proposed in an embodiment of the present application. The ventricular assist device 100 includes a housing assembly having an inlet pipe 50, an impeller 20 for pushing a fluid, and a motor 30 for driving the impeller 20 to rotate in suspension. 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, and the housing assembly is also provided with a fluid inlet 14 and a fluid outlet 15 connected to the chamber 10, and the fluid inlet 14 is provided on the first housing. The impeller 20 can rotate in suspension in the chamber 10, and the rotation of the impeller 20 can generate a centrifugal force for conveying the fluid, so that the fluid can enter the chamber 10 from the fluid inlet 14 and be output from the fluid outlet 15. Among them, the suspended rotation of the impeller 20 means that the impeller 20 does not contact the cavity wall of the chamber 10 when rotating.

[0039] The second housing includes a first side wall 11, the first housing includes a second side wall 12, and the motor 30 includes a stator 31 and a rotor 32 arranged on both sides of the first side wall 11. The stator 31 is fixed to the outer side of the first side wall 11 relative to the chamber 10, and the corresponding rotor 32 is located in the chamber 10. Further, the rotor 32 is fixedly connected to the impeller 20, and when the stator 31 drives the rotor 32 to rotate in the chamber 10, the impeller 20 also rotates synchronously with the rotor 32 in the chamber 10.

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

[0041] See also Figure 3 , Figure 3 A schematic diagram of another ventricular assist system provided in an embodiment of the present 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, and the controller 230 is disposed outside the body, and the controller 230 is 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 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 repeated here.

[0043] In which, the inlet tube 50 is fixed at the apex of the left ventricle. During the implantation or operation of the ventricular assist device 100, the left ventricular assist device 210 or the right ventricular assist device 220, the tube mouth of the inlet tube 50 may be too close to or adjacent to the heart tissue and cause a suction event. A suction event may occur when the fluid inlet 14 interacts with the heart tissue, causing partial or complete blockage of the inlet tube 50. Continuous suction may damage the patient's heart, impair the function of the ventricular assist device system, and cause insufficient perfusion of the patient.

[0044] Based on this, the present application proposes a suction detection method, which calculates the changes in the pumping flow of the ventricular assist device in the time domain and frequency domain respectively, and judges whether suction occurs in the ventricular assist device based on the before and after changes in the pumping flow in the time domain and frequency domain, thereby improving the accuracy of suction detection.

[0045] In combination with the above description, the present application is described below from the perspective of method examples.

[0046] See also Figure 4 , Figure 4 A schematic diagram of a suction detection method provided in an embodiment of the present application is applied to Figure 1 The ventricular assist device shown. Figure 4 As shown, the method includes the following steps.

[0047] S410. Acquire a first flow curve and a second flow curve, wherein the first flow curve is a pumping flow curve of the ventricular assist device in a first first cycle when the ventricular assist device operates at a target speed, and the second flow curve is a pumping flow curve of the ventricular assist device in a second first cycle when the ventricular assist device operates at the target speed.

[0048] During operation of the ventricular assist device 100 in the user's body, the pumping flow through the ventricular assist device 100 depends on the work that the ventricular assist device 100 needs to overcome resistance to pump blood from the left ventricle 128 to the aorta 124. The amount of work done by the ventricular assist device 100 can be quantified as the amount of current that needs to be provided to the motor 30, that is, the motor current corresponds to the amount of current delivered to the motor 30 of the ventricular assist device 100 when the ventricular assist device 100 is operating in the user. During different phases of the cardiac cycle of the user's heart, the load on the motor 30 will change. When the pressure difference in the user's heart changes, the motor current will also change to keep the rotor 32 speed constant. For example, when the flow rate of blood into the aorta 124 increases (such as during systole), the current required by the motor will increase. Therefore, changes in the motor current can help characterize cardiac performance. That is, during the operation of ventricular assist device 100 , ventricular assist device 100 has a current-flow characteristic curve, wherein the greater the current, the more work ventricular assist device 100 does, that is, the greater the pumping flow of 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). The 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 test system to test the relationship curve between the pumping flow rate and the current change of the ventricular assist device 100 at different speeds, and then the current-flow characteristic curve is stored in the control unit 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 obtains 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 uses the pumping flow rate in each first cycle as a set of data. By comparing the changes in two adjacent sets of pumping flow rate data, it can be determined whether the ventricular assist device has pumped. Specifically, the control unit 33 uses the pumping flow rate curve in the first first cycle as the first flow rate curve, and the pumping 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 own condition. For example, the more severe the patient's heart failure is, the shorter the first cycle is. The first cycle can also be set according to the patient's hemodynamic indicators, such as 10s, 20s, 30s, etc.

[0053] S420: Calculate a target time domain deviation and a target frequency domain deviation according to the first flow curve and the second flow curve.

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

[0055] Aortic valve regurgitation, abnormal position of the ventricular assist device 100, abnormal patient heart rate, suction of the ventricular assist device 100, abnormal rotation speed of the ventricular assist device 100 (too high or too low), etc. may all cause abnormal pumping flow of the ventricular assist device 100 in the time domain. There is a large error in judging whether the ventricular assist device 100 is suctioning only by the abnormality of the pumping flow curve in the time domain. When the ventricular assist device 100 is suctioning, the minimum pumping flow in the pumping flow curve of the ventricular assist device 100 will decrease sharply, and a small pulsation peak may be generated between the minimum pumping flow and the maximum pumping flow, and this small pulsation peak will become a small pulse in the frequency domain. Therefore, when the pumping flow curve in the adjacent first cycle has a large deviation in both the time domain and the frequency domain, it can be considered that the probability of suction of the current ventricular assist device 100 is very high.

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

[0057] When the ventricular assist device 100 operates normally, the waveform of the pumping flow of the ventricular assist device 100 in the time domain is generally a sine wave waveform. When the ventricular assist device 100 is pumping, the minimum pumping flow in its pumping flow curve in the time domain will decrease sharply, and a small pulsation peak may be generated between the minimum pumping flow and the maximum pumping flow; in the frequency domain, the amplitude of the fundamental wave component corresponding to the sine wave will decrease, and the harmonic component corresponding to the pulsation peak will be added to the spectrum, so that the energy of the fundamental wave allocation frequency band in the entire spectrum is reduced.

[0058] Wherein, the calculation of the first flow difference according to the first flow curve and the calculation of the second flow difference according to the second flow curve include: obtaining a first pumping flow and a second pumping flow from the first flow curve, the first pumping flow being the maximum pumping flow in the first flow curve, and the second pumping flow being the minimum pumping flow in the first flow curve; obtaining a third pumping flow and a fourth pumping flow from the second flow curve, the third pumping flow being the maximum pumping flow in the second flow curve, and the fourth pumping flow being the minimum pumping flow in the second flow curve; respectively calculating a first average flow and a second average flow, the first average flow being the average flow of the first flow curve, and the second average flow being the average flow of the second flow curve; substituting the first pumping flow, the second pumping flow and the first average flow into a target formula to calculate the first flow difference, and substituting the third pumping flow, the fourth pumping flow and the second average flow into the target formula to calculate the second flow difference.

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

[0060] Specifically, after the control unit 33 obtains the pumping flow rate of the ventricular assist device 100 in the first cycle according to the sampling frequency, it calculates the average flow rate q1 in the first cycle. ave As the first average flow rate, the maximum pumping flow rate q1 in the first cycle is max and minimum pumping flow q1 min As the first pumping flow rate and the second pumping flow rate, respectively, and then substitute them into the target formula to calculate the first flow difference Q1=(q1 ave -q1 min )-(q1 max -q1 ave). Similarly, for the next first cycle, the control unit obtains the pumping flow rate of the ventricular assist device 100 in the next first cycle according to the sampling frequency, and calculates the average flow rate q2 in the first cycle. ave As the third average flow rate, the maximum pumping flow rate q2 in the first cycle is max and minimum pumping flow q2 min As the third pumping flow rate and the fourth pumping flow rate, respectively, they are 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 difference and the first flow difference is taken as the target time domain deviation.

[0061] When judging the pumping flow curve of the ventricular assist device 100 in the time domain, the control unit will also perform Fourier transform on the pumping flow curve in each first cycle, transform each pumping flow curve in the time domain into a spectrum in the frequency domain, and then perform spectrum analysis on each spectrum to obtain the total energy of each spectrum and the energy of the fundamental component frequency band. Specifically, the control unit performs spectrum analysis on the first spectrum transformed from the pumping flow curve of 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; performs spectrum analysis on the second spectrum transformed from the pumping flow curve of 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, and then takes the difference F1-F2 between the first proportion and the second proportion as the target frequency domain deviation.

[0062] S430. Determine whether the ventricular assist device has suction according to the target time domain deviation and the target frequency domain deviation.

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

[0064] For example, judging whether the ventricular assist device has suction based on the target time domain deviation and the target frequency domain deviation includes: determining a first suction probability based on the target time domain deviation, the first suction probability being the probability that the ventricular assist device has suction in the time domain; determining a second suction probability based on the target frequency deviation, the second suction probability being the probability that the ventricular assist device has suction in frequency; determining a target suction probability corresponding to the first suction probability and the second suction probability from a target mapping table; and determining whether the ventricular assist device has suction based on the target suction probability.

[0065] The control unit 33 determines the probability of the ventricular assist device 100 sucking in the time domain according to the magnitude of the target time domain deviation, determines the probability of the ventricular assist device 100 sucking in the frequency domain according to the magnitude of the target frequency domain deviation, and then finally determines whether the ventricular assist device 100 sucks according to the probability of sucking in the time domain and the probability of sucking in the frequency domain.

[0066] Optionally, the determining the first sucking probability according to the target time domain deviation includes: if the target time domain deviation is less than or equal to the first value, determining that the first sucking probability is none; if the target time domain deviation is greater than the first value and less than or equal to the second value, determining that the first sucking probability is low; if the target time domain deviation is greater than the second value and less than the third value, determining that the first sucking probability is medium; if the target time domain deviation is greater than or equal to the third value, determining that the first sucking probability is 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 period and the pumping flow rate curve in the first first period in the time domain is large, and the probability of sucking 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 period and the pumping flow rate curve in the first first period in the time domain is small, and the probability of sucking 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 period and the pumping flow rate curve in the first first period in the time domain is very small, and the probability of sucking 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 period and the pumping flow rate curve in the first first period in the time domain, and there is no possibility of sucking.

[0068] Wherein, the first value is -k times of the second average flow rate, k is greater than 0 and less than 1, the third value is k times of the second average flow rate, and the second value is 0. Exemplarily, k can take values such as 1 / 2, 1 / 3, 1 / 4, 1 / 5, etc. When sucking occurs, the fluctuation of the pumping flow rate of the ventricular assist device in the time domain will increase. Therefore, when the target time domain deviation is less than or equal to -k times of the second average flow rate, it indicates that the fluctuation of the pumping flow rate in the second first period is less than the fluctuation of the pumping flow rate in the first first period, and at this time there is no possibility of the ventricular assist device sucking.

[0069] Optionally, determining the second puff probability based on the target frequency deviation includes: if the target frequency deviation is equal to the second value, determining that the second puff probability is zero; if the target frequency deviation is greater than the second value and less than the fourth value, determining that the second puff probability is low; if the target frequency deviation is greater than or equal to the fourth value, determining that the second puff probability is 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 frequency spectrum of the pumping flow curve in the second first period in the frequency domain and the frequency spectrum of the pumping flow curve in the first first period is large, and the probability of suction is high; if the target frequency domain deviation F1-F2 is less than the fourth value and greater than the second value, it is considered that the deviation between the frequency spectrum of the pumping flow curve in the second first period in the frequency domain and the frequency spectrum of the pumping flow curve in the first first period 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 frequency spectrum of the pumping flow curve in the second first period in the frequency domain and the frequency spectrum of the pumping flow curve in the first first period, and the possibility of suction is 0.

[0071] The fourth value is m times the second proportion, and m is greater than 0 and less than 1. For example, m may be 1 / 5, 1 / 7, 1 / 1 / 8, 1 / 10, etc.

[0072] After obtaining the probability of the ventricular assist device 100 pumping in the time domain and the frequency domain, the control unit determines the pumping probability of the ventricular assist device 100 according to the pre-stored target mapping table. The target mapping table is as follows: Figure 5As shown, when the probability of suction in the time domain is zero and the probability of suction in the frequency domain is zero, the probability of suction of the ventricular assist device 100 is zero; when the probability of suction in the time domain is zero and the probability of suction in the frequency domain is low, the probability of suction of the ventricular assist device 100 is low; when the probability of suction in the time domain is zero and the probability of suction in the frequency domain is high, the probability of suction of the ventricular assist device 100 is low; when the probability of suction in the time domain is low and the probability of suction in the frequency domain is zero, the probability of suction of the ventricular assist device 100 is zero; when the probability of suction in the time domain is low and the probability of suction in the frequency domain is low, the probability of suction of the ventricular assist device 100 is low; when the probability of suction in the time domain is low and the probability of suction in the frequency domain is high, the probability of suction of the ventricular assist device 100 is medium; when the probability of suction in the time domain is medium and the probability of suction in the frequency domain is zero, the probability of suction in the ventricular assist device 100 is low; when the probability of suction in the time domain is medium and the probability of suction in the frequency domain is medium, the probability of suction in the ventricular assist device 100 is medium; when the probability of suction in the time domain is medium and the probability of suction in the frequency domain is high, the probability of suction in the ventricular assist device 100 is high; when the probability of suction in the time domain is high and the probability of suction in the frequency domain is zero, the probability of suction in the ventricular assist device 100 is medium; when the probability of suction in the time domain is high and the probability of suction in the frequency domain is low, the probability of suction in the ventricular assist device 100 is high; when the probability of suction in the time domain is high and the probability of suction in the frequency domain is high, the probability of suction 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 according to the target mapping table. Based on the above method, the control unit determines the probability of aspiration occurring in the subsequent third first cycle, the fourth first cycle, and the i-th first cycle respectively. And if the probability of aspiration occurring in the first cycle is high, an aspiration alarm is issued to prompt the user or medical staff that there is a possibility of aspiration.

[0074] In a possible example, the method further includes: recording a first number and a second number of ventricular assist devices in n first cycles, respectively, the first number being a number with a high probability of aspiration, and the second number being a number with a heavy probability of aspiration; obtaining an aspiration alarm method, and determining an alarm threshold according to the aspiration alarm method; and performing aspiration alarm according to the first number, the second number 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 of the high alarm mode is that the first quantity is greater than the first value; the alarm threshold of the medium alarm mode is that the first quantity is greater than the first value, the second quantity is greater than the second value, and the second value is greater than the first value; the alarm threshold of the low alarm mode is that the first quantity is greater than the second value.

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

[0077] For example, the control unit divides the pumping flow rate within 5 minutes into 30 first cycles with 10 seconds as the first cycle, and then counts the suction probability of the ventricular assist device 100 in the 30 first cycles according to the above method. If a high alarm mode is used, if the number of times the suction probability of the ventricular assist device 100 is high is greater than 10 times, then one suction alarm is recorded and displayed, otherwise no suction alarm is performed. If a medium alarm mode is used, if the number of times the suction probability of the ventricular assist device 100 is high is greater than 10 times and the number of times the suction probability is medium is greater than 20 times, then one suction alarm is recorded and displayed, otherwise no suction alarm is performed. If a low alarm mode is used, if the number of times the suction probability of the ventricular assist device 100 is high is greater than 20 times, then one suction alarm is recorded and displayed, otherwise no suction alarm is performed.

[0078] Furthermore, if the aspiration alarm occurs three times in succession, the control unit may gradually reduce the rotation speed of the ventricular assist device 100 by 100 rpm every 5 minutes until there is no aspiration alarm or the rotation speed of the ventricular assist device 100 exceeds the allowed speed range, and then restore the rotation speed.

[0079] It can be seen that the present application proposes a suction detection method, which obtains a first flow curve and a second flow curve, wherein the first flow curve is a pumping flow curve in the first first cycle when the ventricular assist device is running at a target speed, and the second flow curve is a pumping flow curve in the second first cycle when the ventricular assist device is running at a target speed; the target time domain deviation and the target frequency domain deviation are calculated according to the first flow curve and the second flow curve; and the presence of suction in the ventricular assist device is determined according to the target time domain deviation and the target frequency domain deviation. The present application improves the accuracy of suction detection by calculating the deviation of the pumping flow of the ventricular assist device in the time domain and frequency respectively to detect whether the ventricular assist device is suctioning.

[0080] The above mainly introduces the scheme of the embodiment of the present application from the perspective of the execution process on the method side. It is understandable that in order to realize the above functions, the network device includes a hardware structure and / or software module corresponding to each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiment provided in this article, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0081] For example, the present application provides a control unit for a ventricular assist device, the control unit comprising one or more processors, the one or more processors being used to: obtain a first flow curve and a second flow curve, the first flow curve being a pumping flow curve of the ventricular assist device in a first first cycle when the ventricular assist device operates at a target speed, and the second flow curve being a pumping flow curve of the ventricular assist device in a second first cycle when the ventricular assist device operates at the target speed; calculating a target time domain deviation and a target frequency domain deviation based on the first flow curve and the second flow curve; and determining whether the ventricular assist device is undergoing suction based on the target time domain deviation and the target frequency domain deviation.

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

[0083] case;

[0084] an impeller disposed in the housing;

[0085] A motor driving the impeller to rotate in suspension;

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

[0087] As an example, the present application also provides a medical device, which includes the control device or ventricular assist device described above.

[0088] Among them, the control device of each of the above schemes has the function of implementing the corresponding steps performed by the medical equipment in the above method; the functions can be implemented by hardware, or by hardware executing corresponding software.

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

[0090] See also Figure 6 , Figure 6 It is a structural diagram of a medical device provided in an embodiment of the present application, wherein the medical device comprises: one or more processors, one or more memories, one or more communication interfaces, and one or more programs; the one or more programs are stored in the memories and are configured to be executed by the one or more processors.

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

[0092] Acquire a first flow curve and a second flow curve, wherein the first flow curve is a pumping flow curve in a first first cycle when the ventricular assist device operates at a target speed, and the second flow curve is a pumping flow curve in a second first cycle when the ventricular assist device operates at the target speed;

[0093] Calculating a target time domain deviation and a target frequency domain deviation according to the first flow curve and the second flow curve;

[0094] It is determined whether the ventricular assist device is pumping based on the target time domain deviation and the target frequency domain deviation.

[0095] Among them, all relevant contents of each scenario involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0096] It should be understood that the above-mentioned memory may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type.

[0097] In the embodiment of the present application, the processor of the above-mentioned device may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0098] It should be understood that the "at least one" involved in the embodiments of the present application refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0099] Furthermore, unless otherwise specified, ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, timing, priority or importance of multiple objects. For example, the first information and the second information are only used to distinguish different information, and do not indicate the difference in content, priority, sending order or importance of the two types of information.

[0100] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software units in a processor for execution. The software unit can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor executes the instructions in the memory, and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0101] An embodiment of the present application also provides a computer storage medium, wherein the computer storage medium stores a computer program for electronic data exchange, and the computer program enables a computer to execute part or all of the steps of any method recorded in the above method embodiments.

[0102] The present application also provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute some or all of the steps of any method described in the above method embodiment. The computer program product may be a software installation package.

[0103] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0104] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0105] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the above-mentioned units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0106] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0107] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0108] If the above integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of this 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 for causing a computer device (which can be a personal computer, a server, or a TRP, etc.) to execute all or part of the steps of the methods of various embodiments of this application. The aforementioned memory includes: various media that can store program codes, such as USB flash drives, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), external hard drives, magnetic disks, or optical discs.

[0109] Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program. This program can be stored in a computer-readable memory, and the memory can include: flash drives, ROM, RAM, magnetic disks, or optical discs, etc.

[0110] The above has introduced the embodiments of this application in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A suction detection method, characterized in that: Applied to a ventricular assist device, the method comprises: Acquire a first flow curve and a second flow curve, wherein the first flow curve is a pumping flow curve in a first first cycle when the ventricular assist device operates at a target speed, and the second flow curve is a pumping flow curve in a second first cycle when the ventricular assist device operates at the target speed; Calculating a target time domain deviation and a target frequency domain deviation according to the first flow curve and the second flow curve; It is determined whether the ventricular assist device is pumping based on the target time domain deviation and the target frequency domain deviation.

2. The method according to claim 1, characterized in that The calculating a target time domain deviation and a target frequency domain deviation according to the first flow curve and the second flow curve includes: Calculate a first flow difference according to the first flow curve, and calculate a second flow difference according to the second flow curve; Performing spectrum analysis on the first flow curve and the second flow curve respectively to obtain a first spectrum and a second spectrum; Respectively calculating the ratio of the energy of the fundamental wave component frequency band to the total energy in the first spectrum and the second spectrum to obtain a first ratio and a second ratio; The difference between the second flow difference and the first flow difference is used as the target time domain deviation, and the difference between the first proportion and the second proportion is used as the target frequency domain deviation.

3. The method according to claim 2, characterized in that The calculating the first flow difference according to the first flow curve and the calculating the second flow difference according to the second flow curve comprises: Acquire a first pumping flow rate and a second pumping flow rate from the first flow curve, wherein the first pumping flow rate is a maximum pumping flow rate in the first flow curve, and the second pumping flow rate is a minimum pumping flow rate in the first flow curve; Acquire a third pumping flow rate and a fourth pumping flow rate from the second flow curve, wherein the third pumping flow rate is a maximum pumping flow rate in the second flow curve, and the fourth pumping flow rate is a minimum pumping flow rate in the second flow curve; Calculate a first average flow and a second average flow respectively, wherein the first average flow is an average flow of the first flow curve, and the second average flow is an average flow of the second flow curve; The first pumping flow, the second pumping flow and the first average flow are substituted into the target formula to calculate the first flow difference, and the third pumping flow, the fourth pumping flow and the second average flow are substituted into the target formula to calculate the second flow difference.

4. The method according to claim 3, characterized in that The target formula is: Q = (q ave -q min )-(q max -q ave ), wherein qave is the average pumping flow rate, qmin is the minimum pumping flow rate, and q ave is the maximum pumping flow rate.

5. The method according to claim 2 or 3, characterized in that: The determining whether the ventricular assist device has suction according to the target time domain deviation and the target frequency domain deviation includes: Determining a first suction probability according to the target time domain deviation, the first suction probability being a probability of the ventricular assist device suctioning in the time domain; determining a second pumping probability according to the target frequency deviation, the second pumping probability being a probability of the ventricular assist device pumping at a frequency; Determining target puff probabilities corresponding to the first puff probability and the second puff probability from a target mapping table; It is determined whether the ventricular assist device is pumping based on the target pumping probability.

6. The method according to claim 5, characterized in that The determining a first puff probability according to the target time domain deviation comprises: If the target time domain deviation is less than or equal to a first value, determining that the first puff probability is zero; If the target time domain deviation is greater than the first value and less than or equal to a second value, determining that the first puff probability is low; If the target time domain deviation is greater than the second value and less than a third value, determining that the first puff probability is medium; If the target temporal deviation is greater than or equal to the third value, the first puff probability is determined to be high.

7. The method according to claim 6, characterized in that The determining a second puff probability according to the target frequency deviation comprises: If the target frequency deviation is equal to the second value, determining that the second puff probability is zero; If the target frequency deviation is greater than the second value and less than the fourth value, determining that the second puff probability is low; If the target frequency deviation is greater than or equal to the fourth value, the second puff 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, the third value is k times the second average flow rate, and 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 comprises one or more processors, wherein the one or more processors are configured to: Acquire a first flow curve and a second flow curve, wherein the first flow curve is a pumping flow curve in a first first cycle when the ventricular assist device operates at a target speed, and the second flow curve is a pumping flow curve in a second first cycle when the ventricular assist device operates at the target speed; Calculating a target time domain deviation and a target frequency domain deviation according to the first flow curve and the second flow curve; It is determined whether the ventricular assist device is pumping 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 comprises: case; an impeller disposed in the housing; A motor driving the impeller to rotate in suspension; A control unit connected to the motor, the control unit being used to execute instructions of the steps in the method according to any one of claims 1-10.

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

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for electronic data exchange, wherein the computer program enables a computer to execute the steps of the method according to any one of claims 1 to 9.

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