Blood pump rotating speed regulation and control method based on multi-target parameter optimization and experimental platform

Abstract

The invention relates to a blood pump rotating speed regulation and control method based on multi-target parameter optimization and an experimental platform, and the method comprises the steps: enabling a heart pressure and flow curve after a blood pump is implanted to more accord with normal physiological parameters by adjusting the rotating speed and the suspension position of a blood pump impeller; the method comprises the following steps: constructing an experimental platform with an upper computer, a blood pump, a simulated heart pump, a laser displacement sensor, a pressure sensor, a flow sensor, a micro-motion platform, a fixed base, a liquid storage cavity and an electromagnetic proportional valve as components; firstly, extracted physiological parameters of a patient are given to a blood pump and a simulated heart pump through an upper computer, the heart failure state and the normal physiological state of the patient are simulated through an experiment platform, and then pressure and flow parameters provided when an impeller works at different rotating speeds and suspension positions in the blood pump are measured; and the pressure and the flow of the blood pump are taken as optimization targets, so that the impeller works at different rotating speeds and suspension positions, and the pressure and the flow after the blood pump is assisted better conform to real values of a human body.

Description

Technical field:

[0001] The present invention relates to the field of medical equipment and devices, and in particular to a blood pump speed control method and an experimental platform based on multi-objective parameter optimization. Background technology:

[0002] The heart is an important organ that drives blood circulation in the human body. Once the heart is diseased or has other diseases such as heart failure, the heart's blood output will decrease, thus affecting blood circulation and the normal functioning of the human body. Due to the shortage of existing heart donors, implanting a blood pump is commonly used to treat heart diseases such as heart failure.

[0003] As a rotating machine, the blood pump can adjust the flow rate and head of the device by adjusting the impeller speed. When the impeller speed is adjustable, the flow rate and head of the device are positively correlated with the impeller speed. When the impeller speed is constant, the flow rate and head of the device are negatively correlated. Similarly, when the flow rate or head of the device is constant, the head or flow rate can be changed by controlling the impeller speed. Since the blood pump is a device implanted in the body for the treatment of heart failure, the inlet flow of the blood pump will continue to change due to the patient's degree of heart failure and cardiac cycle. When the impeller speed is constant but the inlet flow is reduced, the device is prone to suction, which affects the heart function. In addition, too high or too low an impeller speed can also cause reflux.

[0004] In this regard, this method controls the impeller suspension position and rotation speed with the outlet pressure and flow of the blood pump as the optimization target while ensuring that the blood pump impeller rotates stably at a specified speed at a specified position, so that the pressure and flow after the blood pump assistance are more consistent with the real values ​​of the human body. Summary of the invention:

[0005] Based on an in-depth study of the background technology, the purpose of the present invention is to provide a heart pump speed control method and experimental platform based on multi-objective parameter optimization. While controlling the blood pump impeller to rotate stably at a specified speed in different suspension positions, the method measures parameters such as the inlet and outlet pressures and flow rates of the heart pump through devices such as pressure sensors and flow sensors, and takes the pressure and flow rate of the blood pump as optimization targets, so that the impeller works at different rotation speeds and suspension positions, so that the pressure and flow rate after the blood pump assistance are more consistent with the real values ​​of the human body.

[0006] The technical solution adopted by the present invention is as follows:

[0007] The experimental platform comprises: a host computer (G), a blood pump (E), a simulated heart pump (A), a laser displacement sensor (D), a pressure sensor (B), a flow sensor (F), a micro-motion platform (C), a fixed base (L), a liquid storage chamber (H), and an electromagnetic proportional valve (J); the liquid storage chamber (H1), the electromagnetic proportional valve (J) and the liquid storage chamber (H2) are connected in series, and the outlet of the liquid storage chamber (H2) and the inlet of the liquid storage chamber (H1) are connected in series with the blood pump (E) and / or the simulated heart pump (A) to form a loop to ensure that the liquid can circulate in the experimental platform, the flow sensor (F2) and the flow sensor (F1) are respectively located at the outlet of the liquid storage chamber (H2) and the inlet of the simulated heart pump (H1), the pressure sensor (B) is respectively located at the inlet and outlet of the blood pump (E), the outlet of the liquid storage chamber (H2) and the inlet of the liquid storage chamber (H1), and the laser displacement sensor (D) is located above the blood pump (E) and is installed on the fixed base (L) through the micro-motion platform (C).

[0008] The loop formed by the liquid storage chamber (H2), the liquid storage chamber (H1), the blood pump (E) and the simulated heart pump (A) includes two branches, one branch only has the simulated heart pump (A2), and the other branch includes the simulated heart pump (A1) and the blood pump (E). By controlling the rotation speed of the simulated heart pump (A1) and the simulated heart pump (A2), the flow and pressure curves under different physiological states can be simulated, wherein the simulated heart pump (A2) is used to simulate the blood output flow and pressure under normal / heart failure conditions, and the simulated heart pump (A1) is used to simulate the blood retention volume and pressure of the heart under heart failure conditions.

[0009] The blood pump includes: a blood pump motor, an upper pump shell, a lower pump shell, and an impeller. The upper pump shell and the lower pump shell form a closed cavity, leaving only an inlet and an outlet for transporting blood. The impeller is located between the upper pump shell and the lower pump shell, and is suspended and rotated by the blood pump motor located below the lower pump shell. The upper pump shell of the blood pump is processed with a through hole and sealed with transparent glass to form an observation hole for observing parameters such as the suspension position of the impeller inside the blood pump.

[0010] The host computer (G) is divided into a communication module, a signal acquisition and processing module and a control module; the communication module is used for data exchange between the signal acquisition and processing module and the control module, as well as data transmission between the host computer (G) and the outside world; the signal acquisition and processing module collects all sensor data of the experimental platform and performs filtering and noise reduction processing, and then transmits the data to the control module through the communication module; the control module is divided into a simulated heart pump (A) control module and a blood pump (E) control module, wherein the simulated heart pump (A) control module sets the actual rotation speed of the simulated heart pump (A) according to the hydraulic characteristic curve of the simulated heart pump (A) and the physiological parameters of the target patient, and the blood pump (E) control module transmits the signal to the current regulation module through the communication module, and changes the direct-axis current and quadrature-axis current of the blood pump motor through the current regulation module to adjust the suspension position and rotation speed of the impeller inside the blood pump (E).

[0011] The present invention also provides a heart pump speed control method based on multi-objective parameter optimization, comprising the following steps:

[0012] S1: Extract and analyze the physiological parameters of the target patient to obtain the heart rate HR and pressure difference curve H of the target patient 0 (t), flow curve Q 0 (t), and the turning point of each phase of the cardiac cycle t i ;

[0013] S2: The obtained parameters are processed and imported into the experimental platform so that it can output the pressure difference curve H of normal state or heart failure state 0 (t) and flow curve Q 0 (t);

[0014] S3: Adjust the inlet flow rate of the heart pump, the speed of the impeller and the specified position to obtain the inlet and outlet pressure difference curve H of the blood pump 1 (x,ω) and flow curve Q 1 (x,ω), and fit it to H 1 =f(x,ω,Q 1 );

[0015] S4: Screening the collected data points according to the suction and reflux conditions and the required pressure and flow rate of the simulation target to determine the speed, suspension position and flow range D of the blood pump under different working conditions;

[0016] S5: For each node t i Randomly generate initial parameters c i =[x i ,ω i ,Q i ] and perform polynomial fitting on all nodes to obtain the impeller speed curve ω(t);

[0017] S6: After comparing the measured values ​​obtained by the experimental platform with the simulated values, the loss function is obtained

[0018] S7: Determine the execution state of the next step according to the size of the loss function. When the loss function is less than 2, it is considered that the blood pump movement speed has met the design requirements. When the loss function is greater than 2, the input parameter c is i Make changes i =[Δx i ,Δω i ,ΔQ i ] until the loss function is less than 2;

[0019] S8: Output the corresponding impeller speed curve. Description of the drawings:

[0020] Figure 1 A schematic diagram of a blood pump experimental platform according to an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of the structure of a blood pump according to an embodiment of the present invention;

[0022] Figure 3 This is a working principle diagram of the blood pump experimental platform according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of a blood pump speed control method according to an embodiment of the present invention;

[0024] Figure 5 The lift, flow rate and speed curve of the blood pump according to the embodiment of the present invention;

[0025] Figure 6 A heart flow curve according to an embodiment of the present invention; Specific implementation method:

[0026] The present invention is further described in detail below.

[0027] In order to facilitate the understanding of the technical content of the present invention, the technical solution is further described below in conjunction with the accompanying drawings. The words "front", "back", "upper", "lower" and other words indicating directions used in the description of the present invention are all statements based on the relationship between the accompanying drawings. The purpose is to facilitate description and cannot be regarded as a limitation on the technical content of the present invention. The words "connection" and other matching relationships involved should be understood in a broad sense unless clearly defined. They can be direct matching, indirect matching, fixed connection, detachable connection, etc. Those skilled in the art can understand the implementation methods based on the purpose of the present invention.

[0028] As the attached Figure 1As shown, the present invention provides an experimental platform for blood pump speed, the experimental platform comprising: a host computer (G), a blood pump (E), a simulated heart pump (A), a laser displacement sensor (D), a pressure sensor (B), a flow sensor (F), a micro-motion platform (C), a fixed base (L), a liquid storage chamber (H), and an electromagnetic proportional valve (J); the liquid storage chamber (H1), the electromagnetic proportional valve (J) and the liquid storage chamber (H2) are connected in series, and the outlet of the liquid storage chamber (H2) and the inlet of the liquid storage chamber (H1) are connected in series with the blood pump (E) and / or the simulated heart pump (A) to form a loop, so as to ensure that the liquid can be in the actual The test platform circulates flow. The flow sensor (F2) and flow sensor (F1) are respectively located at the outlet of the liquid storage chamber (H2) and the inlet of the simulated heart pump (H1), and are used to measure and calculate the actual flow of the test platform and different branches. The pressure sensor (B) is respectively located at the inlet and outlet of the blood pump (E), the outlet of the liquid storage chamber (H2) and the inlet of the liquid storage chamber (H1), and is used to measure and calculate the actual pressure of the test platform and different branches. The laser displacement sensor (D) is installed on the fixed base (L) through the micro-motion platform (C), and the actual suspension position of the impeller is measured through the observation hole of the pump casing on the blood pump.

[0029] The loop formed by the liquid storage chamber (H2), the liquid storage chamber (H1), the blood pump (E) and the simulated heart pump (A) includes two branches, one branch only has the simulated heart pump (A2), and the other branch includes the simulated heart pump (A1) and the blood pump (E). By controlling the rotation speed of the simulated heart pump (A1) and the simulated heart pump (A2), the flow and pressure curves under different physiological states can be simulated, wherein the simulated heart pump (A2) is used to simulate the blood output flow and pressure under normal / heart failure conditions, and the simulated heart pump (A1) is used to simulate the blood retention volume and pressure of the heart under heart failure conditions.

[0030] The host computer (G) is divided into a communication module, a signal acquisition and processing module and a control module; the communication module is used for data exchange between the signal acquisition and processing module and the control module, as well as data transmission between the host computer (G) and the outside world; the signal acquisition and processing module collects all sensor data of the experimental platform and performs filtering and noise reduction processing, and then transmits the data to the control module through the communication module; the control module is divided into a simulated heart pump (A) control module and a blood pump (E) control module, wherein the simulated heart pump (A) control module sets the actual rotation speed of the simulated heart pump (A) according to the hydraulic characteristic curve of the simulated heart pump (A) and the physiological parameters of the target patient, and the blood pump (E) control module transmits the signal to the current regulation module through the communication module, and changes the direct-axis current and quadrature-axis current of the blood pump motor through the current regulation module to adjust the suspension position and rotation speed of the impeller inside the blood pump (E).

[0031] As the attached Figure 2As shown, the blood pump includes: a blood pump motor, an upper pump shell, a lower pump shell, and an impeller. The upper pump shell and the lower pump shell form a closed cavity, leaving only an inlet and an outlet for transporting blood. The impeller is located between the upper pump shell and the lower pump shell, and is suspended and rotated by the blood pump motor located below the lower pump shell. The upper pump shell of the blood pump is processed with a through hole and sealed with transparent glass to form an observation hole for observing parameters such as the suspension position of the impeller inside the blood pump.

[0032] As the attached Figure 3 and attached Figure 4 As shown, the present invention also provides a heart pump speed control method based on multi-objective parameter optimization, comprising the following steps:

[0033] S1: Extract and analyze the physiological parameters of the target patient to obtain the heart rate HR and pressure difference curve H of the target patient 0 (t), flow curve Q 0 (t), and the turning point of each phase of the cardiac cycle t i The heart flow curve is shown in the attached figure. Figure 5 As shown;

[0034] S2: The obtained parameters are processed and imported into the experimental platform so that it can output the pressure difference curve H of normal state or heart failure state 0 (t) and flow curve Q 0 (t);

[0035] S3: Adjust the inlet flow rate of the heart pump, the speed of the impeller and the specified position to obtain the inlet and outlet pressure difference curve H of the blood pump 1 (x,ω) and flow curve Q 1 (x,ω), and fit it to H 1 =f(x,ω,Q 1 ), the pressure-flow-speed curve of the blood pump is shown in the attached Figure 6 As shown;

[0036] S4: Since the blood pump can control the head by changing the impeller speed, the impeller suspension position and the blood pump flow rate, there can be multiple working conditions for the same head. For this, it is necessary to screen the collected data points according to the suction and backflow conditions and the required pressure and flow rate of the simulation target to determine the speed, suspension position and flow range D of the blood pump under different working conditions;

[0037] S5: For each node t i Randomly generate initial parameters c i =[x i ,ω i ,Q i ] and perform polynomial fitting on all nodes to obtain the impeller speed curve ω(t);

[0038] S6: After comparing the measured values ​​obtained by the experimental platform with the simulated values, the loss function is obtained

[0039] S7: Determine the execution state of the next step according to the size of the loss function. When the loss function is less than 2, it is considered that the blood pump movement speed has met the design requirements. When the loss function is greater than 2, the input parameter c is i Make changes i =[Δx i ,Δω i ,ΔQ i ] until the loss function is less than 2;

[0040] S8: Output the corresponding impeller speed curve.

[0041] The present invention provides a heart pump speed control method based on multi-objective parameter optimization, characterized in that: the screening condition of step S4 is H 1 (ω,x)∈[H min ,H max ], Q 1 (ω,x)∈[Q min ,Q max ], where Q min is the minimum value of the inlet flow, Q max is the maximum value of the inlet flow rate, H min is the minimum value of arterial pressure difference, H max is the maximum value of the arterial pressure difference, and the data points that meet the requirements are summarized to obtain (ω,x)∈D.

[0042] The present invention provides a heart pump speed control method based on multi-objective parameter optimization, characterized in that: in step S5, the initial parameter c i The value intervals are {Q(t i )|Q 0 (t i )-0.1 <Q(t i ) 0 (t i )+0.1}, {ω|0<ω<36000 / πd}, {x i |-0.3 <x i <0.3}, (ω i ,x i )∈D, where d is the diameter of the impeller in mm.

[0043] The present invention provides a heart pump speed control method based on multi-objective parameter optimization, characterized in that: in step S7, parameter c i and the changed parameter c i+1 Needs to be satisfied​

[0044] The device is also used to test magnetically suspended blood pumps of different structures. The functions and auxiliary systems of the device cannot be understood as limiting the scope of the invention patent. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A blood pump speed control method and experimental platform based on multi-objective parameter optimization, characterized in that: The device comprises: a host computer (G), a blood pump (E), a simulated heart pump (A), a laser displacement sensor (D), a pressure sensor (B), a flow sensor (F), a micro-motion platform (C), a fixed base (L), a liquid storage chamber (H), and an electromagnetic proportional valve (J); the liquid storage chamber (H1), the electromagnetic proportional valve (J) and the liquid storage chamber (H2) are connected in series, and the outlet of the liquid storage chamber (H2) and the inlet of the liquid storage chamber (H1) are connected in series with the blood pump (E) and / or the simulated heart pump (A) to form a loop to ensure that the liquid can circulate in the experimental platform, the flow sensor (F2) and the flow sensor (F1) are respectively located at the outlet of the liquid storage chamber (H2) and the inlet of the simulated heart pump (H1), the pressure sensor (B) is respectively located at the inlet and outlet of the blood pump (E), the outlet of the liquid storage chamber (H2) and the inlet of the liquid storage chamber (H1), and the laser displacement sensor (D) is located above the blood pump (E) and is installed on the fixed base (L) through the micro-motion platform (C).

2. The blood pump speed control method and experimental platform based on multi-objective parameter optimization according to claim 1, characterized in that: The loop formed by the liquid storage chamber (H2), the liquid storage chamber (H1), the blood pump (E) and the simulated heart pump (A) includes two branches, one branch only has the simulated heart pump (A2), and the other branch includes the simulated heart pump (A1) and the blood pump (E). By controlling the rotation speed of the simulated heart pump (A1) and the simulated heart pump (A2), the flow and pressure curves under different physiological states can be simulated, wherein the simulated heart pump (A2) is used to simulate the blood output flow and pressure under normal / heart failure conditions, and the simulated heart pump (A1) is used to simulate the blood retention volume and pressure of the heart under heart failure conditions.

3. The blood pump speed control method and experimental platform based on multi-objective parameter optimization according to claim 1, characterized in that: The blood pump includes: a blood pump motor, an upper pump shell, a lower pump shell, and an impeller. The upper pump shell and the lower pump shell form a closed cavity, leaving only an inlet and an outlet for transporting blood. The impeller is located between the upper pump shell and the lower pump shell, and is suspended and rotated by the blood pump motor located below the lower pump shell. The upper pump shell of the blood pump is processed with a through hole and sealed with transparent glass to form an observation hole for observing parameters such as the suspension position of the impeller inside the blood pump.

4. The blood pump speed control method and experimental platform based on multi-objective parameter optimization according to claim 1, characterized in that: The host computer (G) is divided into a communication module, a signal acquisition and processing module and a control module; the communication module is used for data exchange between the signal acquisition and processing module and the control module, as well as data transmission between the host computer (G) and the outside world; the signal acquisition and processing module collects all sensor data of the experimental platform and performs filtering and noise reduction processing, and then transmits the data to the control module through the communication module; the control module is divided into a simulated heart pump (A) control module and a blood pump (E) control module, wherein the simulated heart pump (A) control module sets the actual rotation speed of the simulated heart pump (A) according to the hydraulic characteristic curve of the simulated heart pump (A) and the physiological parameters of the target patient, and the blood pump (E) control module transmits the signal to the current regulation module through the communication module, and changes the direct-axis current and quadrature-axis current of the blood pump motor through the current regulation module to adjust the suspension position and rotation speed of the impeller inside the blood pump (E).

5. The blood pump speed control method and experimental platform based on multi-objective parameter optimization according to claim 1, characterized in that: The method comprises the following steps: S1: Extract and analyze the physiological parameters of the target patient to obtain the target patient's heart rate HR, pressure difference curve H0(t), flow curve Q0(t), and the time inflection point t of each stage of the cardiac cycle i ; S2: The obtained parameters are processed and imported into the experimental platform so that it can output the pressure difference curve H0(t) and flow curve Q0(t) in normal state or heart failure state; S3: adjusting the inlet flow rate of the heart pump, the speed of the impeller and the designated position, obtaining the inlet and outlet pressure difference curve H1(x,ω) and the flow curve Q1(x,ω) of the blood pump, and fitting them to H1=f(x,ω,Q1); S4: Screening the collected data points according to the suction and reflux conditions and the required pressure and flow rate of the simulation target to determine the speed, suspension position and flow range D of the blood pump under different working conditions; S5: For each node t i Randomly generate initial parameters c i =[x i ,ω i ,Q i ] and perform polynomial fitting on all nodes to obtain the impeller speed curve ω(t); S6: After comparing the measured values ​​obtained by the experimental platform with the simulated values, the loss function is obtained S7: Determine the execution state of the next step according to the size of the loss function. When the loss function is less than 2, it is considered that the blood pump movement speed has met the design requirements. When the loss function is greater than 2, the input parameter c is i Make changes i =[Δx i ,Δω i ,ΔQ i ] until the loss function is less than 2; S8: Output the corresponding impeller speed curve.

Images