Method for estimating cardiac output, catheter pump system and control method thereof

Abstract

This invention relates to a method for estimating cardiac output, a catheter pump system, and a control method thereof. A data acquisition element is used to acquire the pump operating parameters of the catheter pump and the current temperature rise value ΔT. ’ The data storage element is used to store the original cardiac output Q. heart The estimation relationship between the current temperature rise value ΔT and the data processing element is connected to the data storage element and the data acquisition element, and the current temperature rise value ΔT is obtained by... ’ Substitute into the estimation formula to estimate the cardiac output Q ’ heart Using the heat generated by the normal operation of the catheter pump as the sole heat source for the thermal dilution method, and using the heat source of the catheter pump as a parameter to estimate the heart's own output, without the need to introduce other heat sources, this method can directly estimate the heart's own output, thus ensuring the accuracy of the heart's own output estimation in principle.

Description

Technical Field

[0001] This invention relates to the field of medical technology, and in particular to a cardiac output flow estimation device, a catheter pump system, and a method for estimating cardiac output flow. Background Technology

[0002] In high-risk percutaneous coronary intervention (PCI) procedures, the use of transvalvular catheter pumps can improve blood flow stability and ensure adequate systemic blood supply. Therefore, it is crucial to determine the patient's cardiac performance during the procedure in order to adjust the transvalvular catheter pump support level accordingly.

[0003] Currently, the conventional method for measuring cardiac output is thermodilution, which requires inserting a Swan-Ganz catheter (pulmonary artery floater) and a thermistor into the right ventricle via a blood vessel and placing them within the pulmonary artery. This method increases the complexity and difficulty of the procedure, posing a greater risk of damage and infection to the cardiovascular system. Besides the conventional thermodilution method, there are techniques that can calculate cardiac output based on thermodilution and then indirectly calculate the native heart's cardiac output by combining this with measurements from transvalvular catheter pumps. Therefore, current technologies cannot directly calculate the native heart's cardiac output, which affects the accuracy of cardiac output estimation and, consequently, the precise adjustment of transvalvular catheter pump support levels. Summary of the Invention

[0004] Therefore, it is necessary to provide a cardiac output flow estimation device, catheter pump system, and estimation method to address the technical problem that the cardiac output of the native heart cannot be directly calculated.

[0005] This invention provides a conduit pump system, the conduit pump system comprising:

[0006] The data acquisition element is used to acquire the pump operating parameters of the ducted pump and the current temperature rise value ΔT of the ducted pump. ’ ;

[0007] Data storage element for storing native cardiac output Q heart The estimation relationship between temperature rise ΔT and temperature rise value;

[0008] A data processing element, connected to the data storage element and the data acquisition element, transmits the current temperature rise value ΔT. ’ Substitute into the estimation formula to estimate the cardiac output Q ’ heart .

[0009] In one embodiment, the data processing element is further configured to adjust the cardiac output Q based on the cardiac output. ’heart And the pump output flow rate Q in the pump operating parameters pump Calculate the total output Q tol .

[0010] In one embodiment, the data acquisition element includes a temperature sensor disposed on the motor surface of the duct pump, the current temperature rise value ΔT ’ This is the current temperature rise value on the motor surface of the duct pump.

[0011] In one embodiment, the duct pump system includes:

[0012] The display unit is electrically connected to the data processing element.

[0013] The present invention also provides a method for estimating cardiac output flow, the method comprising the following steps:

[0014] Obtain the pump operating parameters and the current temperature rise value ΔT of the ducted pump. ’ The current temperature rise value ΔT ’ Substitute the original heart output quantity Q heart The estimation relationship between the cardiac output Q and the temperature rise ΔT is used to estimate the cardiac output Q. ’ heart .

[0015] In one embodiment, the temperature rise ΔT of the duct pump is the temperature rise of the motor surface of the duct pump.

[0016] In one embodiment, obtaining the temperature rise value ΔT includes the following steps:

[0017] The temperature rise value ΔT=T max –T0, where T0 is the temperature value before the duct pump starts operating, T max The highest temperature value within the temperature sampling range during the operation of the duct pump; or,

[0018] The temperature rise value ΔT=T max –T min , among which, T min T represents the lowest temperature value within the temperature sampling range during the operation of the duct pump. max The highest temperature value within the temperature sampling range during the operation of the duct pump; or,

[0019] The temperature rise value ΔT=T max –T ave , among which, T ave T represents the average temperature value within the temperature sampling range during the operation of the duct pump. max The highest temperature value within the temperature sampling range during the operation of the duct pump; or,

[0020] The temperature rise value ΔT=T min –T0, where T0 is the temperature value before the duct pump starts operating, T min This represents the lowest temperature value within the temperature sampling range during the operation of the duct pump.

[0021] In one embodiment, the temperature sampling interval includes at least 20 cardiac cycles.

[0022] In one embodiment, the estimation formula includes multiple sub-formulas, each corresponding to a different speed range of the duct pump; the estimation method further includes the following steps:

[0023] The pump operating parameters include the motor current I of the duct pump, based on the motor current I and the current temperature rise value ΔT. ՛ Generate corrected temperature rise value ΔT ՛՛ The corrected temperature rise value ΔT ՛՛ Substitute the values ​​into the estimation formula to estimate the cardiac output Q. ’ heart .

[0024] In one embodiment, the estimation method further includes the following steps:

[0025] The corrected temperature rise value ΔT ՛՛ =ΔT ՛ +ΔT*[(I ave / I ave ՛ ) 2 -1]*ɑ;

[0026] Among them, I ave I represents the average current value of the motor during the temperature sampling range of the duct pump operation. ՛ ave The real-time average current value of the motor of the duct pump is given by α, which ranges from 0.8 to 1.2.

[0027] The present invention also provides a control method for a duct pump system, comprising:

[0028] The cardiac output Q is estimated using the cardiac output estimation method as described in claims 5 to 10. ’ heart ;

[0029] Based on the cardiac output Q ’ heart The pump output flow rate Q in the pump operating parameters pump The total output is calculated as Q. tol .

[0030] In one embodiment, the control method further includes:

[0031] Determine the total output quantity Q tol If the value is within the preset normal threshold, then adjust the pump operating parameters of the duct pump and / or output alarm information.

[0032] In the aforementioned methods for estimating cardiac output, the catheter pump system, and its control method, the heat generated during the normal operation of the catheter pump can be used as the sole heat source for the thermal dilution method. The heat source of the catheter pump can be used as a parameter to estimate the heart's own output without the need to introduce other heat sources. This can directly estimate the heart's own output, ensuring the accuracy of the estimation of the heart's own output in principle. It provides doctors with real-time information on the patient's cardiac performance and offers suggestions for adjusting the catheter pump, effectively improving the operability of the surgery and reducing blood supply insufficiency caused by insufficient support strength of the catheter pump or blood damage caused by excessive support strength of the catheter pump. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the assembly structure of a conduit pump and a data acquisition element according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the usage state structure of an estimation device provided in one embodiment of the present invention;

[0035] Figure 3 A performance curve of flow rate versus pressure difference provided in one embodiment of the present invention;

[0036] Figure 4 A performance curve of motor current versus flow rate is provided for one embodiment of the present invention;

[0037] Figure 5 A schematic diagram comparing state A and state B of a duct pump provided in an embodiment of the present invention;

[0038] Figure 6 Temperature data curve of a duct pump provided in one embodiment of the present invention;

[0039] Figure 7 A fitting curve diagram of the estimation relationship provided in one embodiment of the present invention;

[0040] Figure 8 A flowchart for generating estimation relationships is provided as an embodiment of the present invention;

[0041] Figure 9 A flowchart illustrating the obtained cardiac output volume provided in one embodiment of the present invention.

[0042] Icon labels:

[0043] 100. Catheter pump; 200. Temperature sensor; 300. Data processing element; 400. Display unit; 500. Human original heart; 600. Valve;

[0044] 110. Inlet of the duct pump; 120. Outlet of the duct pump. Detailed Implementation

[0045] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0046] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0050] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0051] See Figure 1 and Figure 2 As shown, one embodiment of the present invention provides a cardiac output flow estimation device. The estimation device includes a data storage element, a data acquisition element, and a data processing element 300. The catheter pump 100 has pump operating parameters, which include various parameter values ​​exhibited by the catheter pump 100 during operation. For example, the pump operating parameters may include at least the pump output flow rate Q. pump The values ​​of parameters such as rotational speed (n), motor current (I), etc., can be used to influence the cardiac output (Q). ’ heart The estimation can be made by those skilled in the art, who can obtain different pump operating parameters of the duct pump 100 as needed, and no limitation is made here. The data acquisition element includes a temperature sensor 200 disposed on the duct pump 100, the temperature sensor 200 being used to acquire the current temperature rise value ΔT of the duct pump 100. ՛ The data processing element 300 is connected to the data storage element and the data acquisition element. The data storage element can be used to store data based on the original cardiac output Q when the same type of catheter pump is placed in the pulsation model for testing. heart The original core output Q generated by the pump operating parameters and the temperature rise value ΔT. heart The estimation relationship between the temperature rise value ΔT and the estimated relationship can be used to estimate the cardiac output Q after the catheter pump is implanted. ’ heart Then the data processing element will process the current temperature rise value ΔT. ’Substitute into the estimation formula to estimate the cardiac output Q ’ heart .

[0052] Temperature sensor 200 is a component that can acquire temperature information and is suitable for assembly with duct pump 100. For example, temperature sensor 200 can be a thermocouple, thermistor, resistance temperature detector (RTD), etc. The signal line of temperature sensor 200 can extend from the cable junction at the tail of duct pump 100 to the surface of duct pump 100, especially to the motor surface of duct pump 100, for example, its probe can be attached to the motor surface to form an assembly. Preferably, the probe can be located in the middle part of the motor in the axial direction.

[0053] The data processing element 300 may include a controller, processor, etc., to meet the corresponding calculation tasks, and is not limited thereto. During data acquisition, the signal acquisition frequency of the temperature sensor 200 can be greater than or equal to 200 Hz. The temperature data is transmitted to the data processing element 300 of the duct pump 100 via a signal line for various processing tasks such as calculation, display, and recording. Furthermore, during data acquisition, the current data of the motor of the duct pump 100 can also be acquired simultaneously. The current data can also be transmitted to the data processing element 300 of the duct pump 100 via a signal line for various processing tasks such as calculation, display, and recording. In addition, those skilled in the art can acquire and transmit other data as needed, and are not limited thereto.

[0054] In this embodiment, the above estimation relationship can be established through the following experiment: using the working environment of the catheter pump 100 simulated by the pulsation model, the actual operating state of the catheter pump 100 is placed into this working environment, and the original cardiac output Q is obtained by running the catheter pump 100. heart (i.e., the output of the pulsating model), pump operating parameters and temperature rise value ΔT, and then based on the original core output Q heart The pump operating parameters and the temperature rise value ΔT are used to generate an estimation formula. After obtaining this estimation formula, the temperature rise value ΔT at different times during operation after the duct pump is implanted can be estimated based on the estimation formula. ՛ The corresponding cardiac output Q ’ heart .

[0055] The temperature of the duct pump 100 mainly depends on the heat generated by the motor. Therefore, the temperature sensor 200 can also be directly installed on the surface of the motor of the duct pump 100 to obtain the temperature rise value of the motor surface of the duct pump 100. Therefore, the temperature rise value ΔT can be directly expressed as the temperature rise value of the motor surface of the duct pump 100.

[0056] In this embodiment, the heat generated by the catheter pump 100 during normal operation is used as the sole heat source for the thermal dilution method, and the heat source of the catheter pump 100 is used as a parameter to estimate the cardiac output Q. ’ heart Without introducing other heat sources, this allows for direct estimation of the cardiac output Q of the human native heart (500). ’ heart In principle, this ensures the heart's own output Q. ’ heart The high accuracy of the estimation can be used to provide doctors with information about the patient's cardiac performance and to give adjustment suggestions for the catheter pump 100, which effectively improves the operability of the operation and reduces blood supply insufficiency caused by insufficient support strength of the catheter pump 100 or blood damage caused by excessive support strength of the catheter pump 100.

[0057] Accordingly, the present invention also provides a catheter pump system, which includes a catheter pump and the estimation device. Therefore, this catheter pump system can estimate cardiac output by means of the estimation device and the catheter pump, so as to better control the operation of the catheter pump. Furthermore, the catheter pump system may also include a display unit 400, such as a display screen, which is electrically connected to the data processing element and can be used to display various data information, including but not limited to the native cardiac output Q. heart Various pump operating parameters, temperature rise ΔT, cardiac output Q ’ heart etc. are not specified here.

[0058] Accordingly, the present invention also provides a method for estimating cardiac output, the estimation method comprising the following steps:

[0059] Start the duct pump and obtain the current temperature rise value ΔT of the duct pump. ’ Estimate the current temperature rise ΔT based on the stored estimation formula. ’ Corresponding cardiac output Q ’ heart .

[0060] This estimation method can be implemented based on the aforementioned estimation device and catheter pump system, or it can be implemented using other suitable devices or systems. Those skilled in the art can choose other devices according to their needs, and no limitation is made here. This estimation method can also utilize the heat generated by the catheter pump 100 during normal operation as the sole heat source for the thermal dilution method to directly estimate the cardiac output Q of the human native heart 500. ’ heart In principle, this ensures the heart's own output Q. ’ heartFor the accuracy of the estimation, please refer to the previous records, which will not be repeated here.

[0061] The estimation device, the duct pump system, and the estimation method essentially only use the temperature rise value ΔT of the duct pump 100 (such as the surface of the duct pump 100, especially the surface of the motor) as the estimation parameter, and its theoretical basis is as follows:

[0062] See Figure 3 The figure shows a performance curve of the duct pump 100 at a specific rotational speed, representing the flow rate of the duct pump 100 and the pressure difference between its inlet 110 and outlet 120. The horizontal axis represents the flow rate Q (L / min) of the duct pump 100, and the vertical axis represents the pressure difference ΔP (mmHg) between the inlet 110 and outlet 120. The specific operation to obtain this performance curve is as follows: The duct pump 100 is placed in a circulating fluid pipeline, which may include a throttle valve, a pressure sensor, and a flow sensor. During the measurement process, the rotational speed n of the duct pump 100 is kept constant. The opening of the throttle valve is adjusted, and the pressure difference between the inlet 110 and outlet 120 is measured as ΔP. ​​The reading from the flow sensor is recorded as the flow rate Q of the duct pump 100. The data of pressure difference ΔP and flow rate Q after each adjustment of the throttle valve are plotted in a table, thus obtaining the performance curve of the duct pump 100 at the current constant rotational speed n. Using the same method, the performance curves of the duct pump 100 at other constant speeds n can be obtained. Figure 3 It can be seen that the curve characteristics in this performance curve indicate that a smaller pressure difference ΔP corresponds to a larger flow rate Q, and the two are inversely proportional. That is, the smaller the pressure difference ΔP, the larger the flow rate Q.

[0063] See Figure 4 The figure shows the performance curve of the motor current I (A) of the duct pump 100 and the flow rate Q (L / min) of the duct pump 100 (the voltage of the duct pump 100 remains constant). The horizontal axis represents the flow rate Q (L / min) of the duct pump 100, and the vertical axis represents the motor current I (A) of the duct pump 100. The curve characteristics of this performance curve show that a larger flow rate Q corresponds to a higher motor current I, and the two are positively correlated, that is, the larger the flow rate Q, the larger the motor current I.

[0064] comprehensive Figure 3 and Figure 4 As shown by the two curves, a smaller pressure difference ΔP corresponds to a higher motor current I. The pressure difference ΔP and the motor current I are positively correlated, that is, the smaller the pressure difference ΔP, the larger the motor current I.

[0065] See Figure 5It can be seen that during the pulsation simulation of the catheter pump 100, the catheter pump 100 operates at a constant speed n. Due to the opening and closing of valve 600, the catheter pump 100 will operate in two states, namely, state A: valve 600 is closed, the inlet pressure 110 of the catheter pump is the left ventricular pressure, and the outlet pressure is the aortic pressure. At this time, the pressure difference ΔP is large, the flow rate Q is small, and the motor current I is low. Correspondingly, the heat generated by the motor of the catheter pump 100 is small. At this time, the heat dissipation of the catheter pump 100 (such as the surface of the catheter pump 100, especially the surface of the motor) is mainly... The heat dissipation of the duct pump 100 relies on the convective heat transfer effect brought about by the flow rate. State B: Valve 600 is open, the pressure of the left ventricle and the aorta is connected, the pressure difference ΔP between the inlet 110 and outlet 120 of the duct pump is small, the flow rate Q is large, and the motor current I is high. Correspondingly, the motor of the duct pump 100 generates a lot of heat. At this time, the heat dissipation of the duct pump 100 (such as the surface of the duct pump 100, especially the surface of the motor) mainly relies on the convective heat transfer effect brought about by the flow rate of the duct pump 100 and the flow rate of the human native heart 500.

[0066] See Figure 6 The figure shows the temperature data of the catheter pump 100 (such as the surface of the catheter pump 100, especially the surface of the motor) obtained during the testing phase. The specific test is as follows: In the pulsation model (the simulated working environment of the catheter pump 100), the temperature of the simulated blood liquid is maintained at T0, such as T0 = 37°C. The catheter pump 100 is controlled to operate at a constant speed n, such as the speed of the catheter pump 100 n = 24000 rpm. The controlled variable in the experiment is the cardiac output Q of the left ventricle. ’ heart (Excluding the pump output flow Q generated by the duct pump 100) pump ), assuming Figure 6 The four curves T1, T2, T3, and T4 correspond to the cardiac output Q, respectively. ’ heart The motor temperature curves are for 1L / min, 2.5L / min, 4L / min and 5.5L / min. The fluctuations in the curves are due to pulsation. As the aortic valve opens and closes, the working state of the catheter pump 100 continuously switches between state A and state B.

[0067] Assumption Figure 6The horizontal axis represents the time sampling point, and the vertical axis represents the temperature of the tubular pump 100 (such as the surface of the tubular pump 100, especially the surface of the motor). Before time point T0, the tubular pump 100 is not started, and its temperature is equal to the temperature T0 of the isothermal liquid. From time point T0 onwards, the tubular pump 100 starts, and its temperature begins to rise. Temperature data is recorded from this point. After a certain number of cardiac cycles, such as a temperature sampling interval of more than 20 cardiac cycles, especially after 30 cardiac cycles, the obtained temperature data are averaged to obtain T. ave Then calculate the temperature rise ΔT of the duct pump 100 = (T ave - T0). By Figure 6 It can be seen that the temperature rise ΔT increases with the cardiac output Q. ’ heart The value of temperature rise (ΔT) decreases as temperature rise increases, and the two have a monotonic relationship. Therefore, it can be determined that the cardiac output (QQ) can be estimated by using the value of temperature rise (ΔT). ’ heart The value.

[0068] Therefore, based on the above conclusions, and considering the temperature rise ΔT of the catheter pump 100 and the cardiac output Q of the human native heart 500... ’ heart The monotonic relationship enables the realization of 500 times the cardiac output Q of the human native heart. ’ heart Direct estimation.

[0069] In one embodiment, the above-mentioned estimation relationship can be generated by the following steps: simulating the working environment of the catheter pump 100. In this embodiment, the catheter pump is placed into a pulsation model to simulate the working environment, and the pump operating parameters of the catheter pump 100 and the original cardiac output Q in the working environment are obtained. heart and temperature rise value ΔT; based on the original heart output Q heart The pump operating parameters and the temperature rise value ΔT generate the original core output Q. heart The estimation relationship between the temperature rise value ΔT and the temperature rise value ΔT is given in this embodiment as ΔT=A*Q. ՛ heart + B, where A and B are constant coefficients. Specifically, this can be achieved by maintaining the pump operating parameters n of the catheter pump 100 at a constant value; adjusting the original cardiac output Q. heart In different original heart output quantities Q heart Under these conditions, multiple temperature rise values ​​ΔT of the catheter pump 100 are collected; based on multiple original cardiac output values ​​Q heart The original core output quantity Q is generated by multiple temperature rise values ​​ΔT. heart The relationship between the estimated temperature rise value ΔT and the original cardiac output Q is...heart The temperature rise value ΔT of the duct pump 100 can be the temperature rise value of the motor surface of the duct pump 100, that is, the temperature rise value of the motor surface of the duct pump 100 can be directly obtained as the temperature rise value ΔT of the duct pump 100.

[0070] See Figure 7 and Figure 8 As shown, Figure 7 This represents the different native heart outputs Q. heart The temperature rise ΔT of the catheter pump 100 can be estimated using a fitted curve. This fitted curve visually demonstrates the relationship between the estimated temperature rise ΔT and the actual temperature rise. Therefore, when the temperature rise ΔT of the catheter pump 100 is known, the cardiac output Q can be directly estimated. ’ heart , Figure 7 The figure shows a linear relationship fit, and the estimated relationship is: ΔT=A*Q ՛ heart + B, Figure 7 R in 2 is the coefficient of determination in linear regression.

[0071] Figure 9 The diagram illustrates the specific process for estimating cardiac output. After implantation of the catheter pump, the first step is to determine if the implantation position is correct. If correct, the process then proceeds to estimate cardiac output, specifically as follows:

[0072] Collect temperature data of the motor surface of the duct pump 100 and calculate the current average temperature T. ՛ 0. Set the rotational speed n of the duct pump to operate at the current speed n. After the duct pump 100 starts and maintains a constant speed n, collect the temperature data of the motor surface of the duct pump 100, and calculate the average temperature T based on the collected temperature data. ՛ ave At this point, the initial temperature rise ΔT can be calculated. ՛ = (T ՛ ave - T ՛ 0), then based on the motor current I and the current temperature rise value ΔT ՛ Generate corrected temperature rise value ΔT ՛՛ ΔT ՛ The correction process can be achieved using the following formula, and the resulting temperature rise value is ΔT. ՛՛ :

[0073] That is, ΔT ՛՛ =ΔT ՛ +ΔT*[(I ave / I ՛ ave ) 2 -1]*ɑ; where, Iave I represents the average current value of the motor during the temperature sampling range of the duct pump 100 during operation. ՛ ave The real-time average current value of the motor of the duct pump 100 is given, and the value of α ranges from 0.8 to 1.2. The corrected temperature rise value ΔT is obtained. ՛՛ Then, the corrected temperature rise value ΔT can be obtained. ՛՛ Substitute the values ​​into the estimation formula to estimate the current cardiac output Q. ’ heart .

[0074] The pump output flow rate Q generated by the duct pump 100 itself pump The output can be estimated by measuring the motor current of the duct pump 100 and combining it with the rotational speed n of the duct pump 100. Assume the total output is Q. tol Then Q can be used tol = Q heart + Q pump The total output is calculated as Q. tol The total output is Q. tol All data results can be displayed on the display unit 400 for the doctor's reference, and can be used to assess the performance of the patient's native heart 500 during surgery, assisting the doctor in determining the support level of the catheter pump 100. If the total output is Q... tol If the level is not within the normal range, the pump speed n can be reset to another speed n, and the pump can be run at that other speed n. Then, the above steps are repeated until the total output is determined to be Q. tol If the level is within the normal range, the duct pump can operate at the corresponding speed n.

[0075] The aforementioned estimation formula includes multiple sub-formulas, each corresponding to a different rotational speed of the catheter pump. Therefore, the sub-formula matching the specified rotational speed can be used for calculation. In other words, estimation formulas and their fitting curves for other rotational speeds n can also be obtained. For example, the rotational speed n can be limited to representative values ​​such as 15000 rpm, 20000 rpm, 24000 rpm, 30000 rpm, or 33000 rpm. For instance, in one embodiment, the rotational speed n of the catheter pump 100 can be adjusted to generate the original cardiac output Q under different rotational speed n conditions. heart And the multiple estimation formulas for the temperature rise value ΔT, the corresponding estimation formulas and their fitting curves can realize the cardiac output Q at the corresponding rotational speed n. ’ heart The estimate.

[0076] The temperature rise value ΔT of the catheter pump 100 essentially characterizes the temperature rise level of the catheter pump 100 under normal operating conditions due to the influence of blood flow convection heat transfer, especially the temperature rise level of the motor of the catheter pump 100 under normal operating conditions due to the influence of blood flow convection heat transfer. Therefore, the temperature rise value ΔT is not limited to the original temperature value before the catheter pump 100 is started and the average temperature obtained within the temperature sampling interval after the catheter pump 100 is started, that is, ΔT = (T ave - T0), as long as it can reflect the temperature rise level of the duct pump 100, especially its motor, those skilled in the art can choose according to their needs, and there is no limitation here.

[0077] In one embodiment, the temperature rise value ΔT can be obtained in various ways, for example, the temperature rise value ΔT=T max –T0, where T0 is the temperature value of the duct pump 100 before operation, T max This refers to the highest temperature value within the temperature sampling range during the operation of the duct pump 100. Alternatively, the temperature rise value ΔT = T max –T min , among which, T min T represents the lowest temperature value within the temperature sampling range during the operation of the duct pump 100. max This refers to the highest temperature value within the temperature sampling range during the operation of the duct pump 100. Alternatively, the temperature rise value ΔT = T max –T ave , among which, T ave T represents the average temperature value within the temperature sampling interval during the operation of the duct pump 100. max This refers to the highest temperature value within the temperature sampling range during the operation of the duct pump 100. Alternatively, the temperature rise value ΔT = T min –T0, where T0 is the temperature value of the duct pump 100 before operation, T min This is the lowest temperature value within the temperature sampling range during the operation of the duct pump 100.

[0078] In one embodiment, the temperature sampling interval includes at least 20 cardiac cycles, for example, acquired after 30 cardiac cycles. Specifically, the temperature sampling interval can be 20 cardiac cycles, 25 cardiac cycles, 30 cardiac cycles, 35 cardiac cycles, 40 cardiac cycles, 45 cardiac cycles, 50 cardiac cycles, 55 cardiac cycles, or 60 cardiac cycles, etc., and is not limited here.

[0079] In a specific estimation embodiment, taking the temperature rise of the motor surface of the duct pump 100 as an example, the duct pump 100 can be placed inside the body and put into normal working condition. Before turning on the duct pump 100, the temperature data of the motor surface of the duct pump 100 is collected and the current average temperature T is calculated.՛ 0. After the tubing pump 100 starts and maintains a constant speed n, the temperature data of the motor surface of the tubing pump 100 is collected, ensuring that the temperature sampling interval is more than 20 cardiac cycles. For example, at 30 cardiac cycles, the average temperature T is calculated based on the collected temperature data. ՛ ave At this point, the current temperature rise value ΔT ՛ = (T ՛ ave - T ՛ 0). Obtain the current temperature rise value ΔT of the duct pump 100. ՛ Then, the current temperature rise value ΔT is... ՛ Substituting the values ​​into the estimation formula, the current cardiac output Q can be estimated. ’ heart .

[0080] Because pulsation models may deviate from the real human body environment, and different patients have different cardiovascular structures and blood characteristics, the obtained ΔT... ՛ Corrective treatment is performed, ΔT ՛ The corrective treatment can be calculated based on the current and temperature rise data of the catheter itself. Specifically, the motor current I of the catheter pump 100 can be obtained, and the corrective treatment can be performed based on the motor current I and the current temperature rise value ΔT. ՛ Generate corrected temperature rise value ΔT ՛՛ The corrected temperature rise value ΔT ՛՛ Substitute the values ​​into the estimation formula to estimate the current cardiac output Q. ’ heart Therefore, during the above simulation process, while recording the temperature data of the tubing pump 100, the motor current data of the tubing pump 100 can also be recorded, for example, to calculate the average current I over a certain number of cardiac cycles. ave The sampling interval for current data (referred to as the current sampling interval) can be consistent with the sampling time for temperature data (referred to as the temperature sampling interval). Averaging the obtained current data yields I. ave .

[0081] ΔT ՛ The correction process can be achieved using the following formula, and the resulting temperature rise value is ΔT. ՛՛ :

[0082] That is, ΔT ՛՛ =ΔT ՛ +ΔT*[(I ave / I ՛ ave ) 2 -1]*ɑ; where, I aveI represents the average current value of the motor during the temperature sampling range of the duct pump 100 during operation. ՛ ave The real-time average current value of the motor of the catheter pump 100 is α, and the value of α ranges from 0.8 to 1.2. The correction coefficient α can be obtained by testing on a pulsation model. For example, by controlling the magnitude of peripheral resistance, the blood circulation system of different patients can be simulated, and the correction coefficient α can be calculated. The magnitude of the correction coefficient α is related to the characteristics of the catheter pump 100 and the test conditions. For example, the value of the correction coefficient α can be 0.8, 0.9, 1.0, 1.1, 1.2, etc. Those skilled in the art can choose appropriate values ​​according to actual needs, and no limitation is made here.

[0083] The pump output flow rate Q generated by the duct pump 100 itself pump The output can be estimated by measuring the motor current of the duct pump 100 and combining it with the rotational speed n of the duct pump 100. Assume the total output is Q. tol Then Q tol = Q heart + Q pump Q heart Q pump Q tol All data results can be displayed on the display unit 400 for doctors to refer to, and can be used to assess the performance of the patient's native heart 500 during surgery, and assist doctors in judging the support level of the catheter pump 100.

[0084] In addition, this embodiment also provides a control method for a duct pump system. In this embodiment, the control method can be configured to automatically determine the total output Q. tol Whether the value is within the preset normal threshold. In this embodiment, the normal threshold refers to the normal output range of the human heart, and the total output Q. tol An excessively high or low value will trigger an alarm program, automatically providing an alarm message and prompting the doctor to adjust the support level of catheter pump 100; and / or, automatically adjust the current pump operating parameters of the catheter pump. It can also be used to monitor the patient's cardiac performance before removing catheter pump 100; that is, when the doctor is preparing to remove catheter pump 100, the support level of catheter pump 100 is gradually reduced, and the cardiac output Q of the native heart 500 is continuously observed. heart It can determine whether the human native heart 500 is recovering its normal function, and thus determine whether to stop the catheter pump 100 and remove it from the human body.

[0085] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0086] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A duct pump system, characterized in that, The duct pump system includes: The data acquisition element is used to acquire the pump operating parameters of the ducted pump and the current temperature rise value ΔT of the ducted pump. ’ ; Data storage element for storing native cardiac output Q heart The estimation relationship between temperature rise ΔT and temperature rise value; A data processing element, connected to the data storage element and the data acquisition element, transmits the current temperature rise value ΔT. ’ Substitute into the estimation formula to estimate the cardiac output Q ’ heart .

2. The duct pump system according to claim 1, characterized in that, The data processing element is also configured to process the cardiac output Q. ’ heart And the pump output flow rate Q in the pump operating parameters pump Calculate the total output Q tol .

3. The duct pump system according to claim 1, characterized in that, The data acquisition element includes a temperature sensor disposed on the surface of the motor of the duct pump, and the current temperature rise value ΔT ’ This is the current temperature rise value on the motor surface of the duct pump.

4. The duct pump system according to claim 1, characterized in that, The duct pump system includes: The display unit is electrically connected to the data processing element.

5. A method for estimating cardiac output flow, characterized in that, The estimation method includes the following steps: Obtain the pump operating parameters and the current temperature rise value ΔT of the ducted pump. ’ The current temperature rise value ΔT ’ Substitute the original heart output quantity Q heart The estimation relationship between the cardiac output Q and the temperature rise ΔT is used to estimate the cardiac output Q. ’ heart .

6. The estimation method according to claim 5, characterized in that, The temperature rise value ΔT of the duct pump is the temperature rise value of the motor surface of the duct pump.

7. The estimation method according to claim 5, characterized in that, Obtaining the temperature rise value ΔT includes the following steps: The temperature rise value ΔT=T max –T0, where T0 is the temperature value before the duct pump starts operating, T max The highest temperature value within the temperature sampling range during the operation of the duct pump; or, The temperature rise value ΔT=T max –T min , among which, T min T represents the lowest temperature value within the temperature sampling range during the operation of the duct pump. max The highest temperature value within the temperature sampling range during the operation of the duct pump; or, The temperature rise value ΔT=T max –T ave , among which, T ave T represents the average temperature value within the temperature sampling range during the operation of the duct pump. max The highest temperature value within the temperature sampling range during the operation of the duct pump; or, The temperature rise value ΔT=T min –T0, where T0 is the temperature value before the duct pump starts operating, T min This represents the lowest temperature value within the temperature sampling range during the operation of the duct pump.

8. The estimation method according to claim 7, characterized in that, The temperature sampling interval includes at least 20 cardiac cycles.

9. The estimation method according to claim 5, characterized in that, The estimation formula includes multiple sub-formulas, each corresponding to a different speed range of the duct pump; the estimation method further includes the following steps: The pump operating parameters include the motor current I of the duct pump, based on the motor current I and the current temperature rise value ΔT. ՛ Generate corrected temperature rise value ΔT ՛՛ The corrected temperature rise value ΔT ՛՛ Substitute the values ​​into the estimation formula to estimate the cardiac output Q. ’ heart .

10. The estimation method according to claim 9, characterized in that, The estimation method further includes the following steps: The corrected temperature rise value ΔT ՛՛ =ΔT ՛ +ΔT*[(I ave / I ave ՛ ) 2 -1]*ɑ; Among them, I ave I represents the average current value of the motor during the temperature sampling range of the duct pump operation. ՛ ave The real-time average current value of the motor of the duct pump is given by α, which ranges from 0.8 to 1.

2.

11. A control method for a duct pump system, characterized in that, include: The cardiac output Q is estimated using the method for estimating cardiac output as described in any one of claims 5 to 10. ’ heart ; Based on the cardiac output Q ’ heart The pump output flow rate Q in the pump operating parameters pump The total output is calculated as Q. tol .

12. The control method according to claim 11, characterized in that, The control method further includes: Determine the total output quantity Q tol If the value is within the preset normal threshold, then adjust the pump operating parameters of the duct pump and / or output alarm information.

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