ECMO cannula performance test device and test method thereof

Abstract

The application discloses a medical instrument detection technical field, and relates to an ECMO cannula performance test equipment and a test method thereof, which comprises a visual box body and an intelligent control box, the visual box body is used for installing a cannula to be tested and providing a liquid environment, the cannula is connected with a water inlet, a pulsating flow generation module, a main flow pump, a flow meter and a water outlet in the visual box body through a circulating pipeline to form a continuous liquid passage, and the visual box body is additionally provided with a first pressure sensor for testing the water pressure of the cannula, a second pressure sensor for testing the liquid pressure of the cannula, a micro pressure sensor for testing the pressure values at different positions in the cannula and a strain monitoring device for monitoring the deformation degree of the cannula. The application realizes the control of the size of the liquid flow through the cannula, the flow speed and the pulsating flow, and can output the internal pressure field distribution of the cannula, the corresponding flow pressure drop curve and the structural deformation analysis diagram.

Description

Technical Field

[0001] This invention relates to an ECMO cannulation performance testing device and its testing method, belonging to the field of medical device testing technology. Background Technology

[0002] Extracorporeal membrane oxygenation (ECMO) is an advanced life support technology primarily used clinically for individuals with heart or respiratory failure. It temporarily or partially replaces the function of the heart and lungs in cases of severe cardiopulmonary failure, buying time for treatment and recovery. The core principle of ECMO is to draw blood from a vein using an extracorporeal circulation device, oxygenate it through an artificial membrane lung (membrane lung), replenish oxygen, and remove carbon dioxide. The oxygenated blood is then returned to the patient via a vein or artery.

[0003] ECMO mainly consists of intravascular cannulas, connecting tubing, a power pump, an oxygenator, a supply tubing, and a monitoring system. When ECMO is operating, different cannula sizes have varying effects on the blood flow through them, which in turn affects the patient's blood pressure and oxygen saturation. To improve the safety of ECMO cannula use, it is necessary to test the internal pressure distribution of different cannula sizes and the pressure drop across the entire cannula corresponding to the flow rate. Currently, there is a lack of dedicated equipment for performance testing of ECMO cannulas, and it is also impossible to test the internal pressure distribution and cannula deformation. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an ECMO cannula performance testing device and its testing method. A circulation pipeline is constructed to simulate the blood flow environment in the human body. During the test, as the flow rate of the fluid flowing through the cannula changes dynamically, the internal pressure value of the cannula, the pressure difference before and after cannula insertion, and the deformation of the cannula are measured. After processing by an intelligent control system, the device can then draw a cloud map of the internal pressure field distribution, a flow rate-pressure drop curve relationship diagram, and a structural deformation analysis diagram. The device is easy to operate and provides an intuitive display.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] In a first aspect, the present invention provides an ECMO cannula performance testing device, comprising: a visualization chamber and an intelligent control box. The visualization chamber is used to install the cannula to be tested and provide a liquid environment. The cannula is connected in sequence to an inlet, a pulsating flow generation module, a main flow pump, a flow meter, and an outlet within the visualization chamber via a circulation pipeline to form a continuous liquid path. The visualization chamber is also equipped with a first pressure sensor for testing the water pressure of the cannula, a second pressure sensor for testing the pressure of the liquid flowing out of the cannula, a miniature pressure sensor for testing the pressure values ​​at different locations within the cannula, and a strain monitoring device for monitoring the degree of cannula deformation. The intelligent control box regulates the liquid flow rate and pulsation state of the continuous liquid path by controlling the main flow pump and the pulsating flow generation module. The miniature pressure sensor, flow meter, first pressure sensor, second pressure sensor, and strain monitoring device feed the detection information back to the intelligent control box through a circuit system for analysis of the internal pressure field distribution, flow rate pressure drop, and structural deformation of the cannula, and then outputs an analysis graph.

[0007] Furthermore, the visualization enclosure is connected to a temperature control module for controlling the liquid temperature and a viscosity control system for adjusting the fluid viscosity.

[0008] Furthermore, the bottom of the visualization box is provided with a concave groove, and multiple movable brackets for placing the ECMO cannula, the first pressure sensor, and the second pressure sensor on the same horizontal plane are installed on the concave groove.

[0009] Furthermore, the intelligent control box is equipped with a control circuit including a PLC, and the control circuit is electrically connected to a miniature pressure sensor, a main flow pump, a flow meter, a pulsating flow generation module, a first pressure sensor, a second pressure sensor, and a strain monitoring device. The surface of the intelligent control box is equipped with a water pump switch button, a uniform flow increase mode button, a pulsating flow mode button, a pressure drop indicator light, a deformation indicator light, a USB flash drive interface, and a touch screen, all electrically connected to the control circuit.

[0010] Furthermore, the liquid environment within the visualization chamber includes at least one of the following: glycerol, water, phosphate buffer solution, and suspended particulate solution.

[0011] Furthermore, there are multiple miniature pressure sensors, and the sensor contacts are located on the inner surface of the cannula.

[0012] Furthermore, the analysis of the internal pressure field distribution, flow rate pressure drop, and structural deformation of the insertion tube includes: pressure field distribution interpolation calculation, dynamic flow rate pressure drop relationship analysis, and structural deformation risk index assessment. The pressure field distribution interpolation calculation formula is as follows: In the formula: P(x,y) is the interpolated pressure value at any position (x,y) inside the cannula; wi is the weighting coefficient; Pi is the measured value of the i-th micro pressure sensor; n is the number of sensor points; α is the fluid dynamics model correction factor; CFD(x,y) is the pressure Laplace operator in the fluid dynamics model.

[0013] Furthermore, the dynamic flow-pressure drop relationship analysis formula is as follows: In the formula: ΔPd is the dynamic pressure drop; Q is the real-time flow rate; denoted as , where A is the rate of change in flow rate; f is the pulse amplitude; t is the heart rate; and K1, K2, and K3 are model coefficients.

[0014] Furthermore, the formula for assessing the structural deformation risk index is as follows: In the formula: Rs is the deformation risk index. These are the measured strain values; σ is the reference strain threshold; σ is the standard deviation of stress fluctuation; β and γ are weighting coefficients.

[0015] Secondly, the present invention provides a testing method for an ECMO cannulation performance testing device, comprising:

[0016] S1: Connect the tube to be tested to the pipeline at the front end of the second pressure sensor, and then place it horizontally on the movable bracket in the concave groove at the bottom of the visualization box; place the first pressure sensor on the movable bracket, at the same horizontal line as the tube, connect the miniature pressure sensor to the tube, and attach the strain monitoring device to the outer wall of the tube.

[0017] S2: Open the water valve of the visualization chamber to fill with liquid. When the liquid in the visualization chamber reaches the specified capacity, close the water valve, open the temperature control module, adjust the liquid temperature to a suitable temperature that simulates human blood, open the viscosity control system, and set the initial viscosity parameters according to the test requirements.

[0018] S3: Turn on the intelligent control box, set the parameters of the pulsating flow generation module through the touch screen to simulate different pulsatile blood flow scenarios, adjust the current speed, speed increase control, and maximum speed to the specified value; select the uniform flow mode or pulsating flow mode, turn on the water pump switch button, and the liquid will start circulating according to the current settings;

[0019] S4: Connect the USB flash drive to the USB flash drive interface, click the touch screen to start data recording. In the constant flow mode, turn on the self-increase button. The liquid flow rate changes according to the currently set increase value and adjusts the flow rate step according to the real-time pressure drop changes. In the pulsating flow mode, the liquid exhibits a pulsating flow state.

[0020] S5: After the flow rate circulates stably and reaches the preset maximum speed, turn off the water pump switch to end the uniform flow mode; after the test data is collected, turn off the water pump switch to end the pulsating flow mode.

[0021] S6: The touchscreen displays the internal pressure field distribution cloud map of the cannula, the corresponding flow rate and pressure drop curve relationship diagram, the structural deformation analysis diagram, and the flow distribution ratio analysis results of the main hole and each side hole of the cannula with side holes. At the same time, the intelligent control box uses test data to correct the CFD digital model and displays the predicted performance curves under different conditions. The test data can be exported via USB flash drive for further in-depth analysis.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0023] I. This invention achieves control over the flow rate, flow rate increase, and pulsating flow of liquid flowing through the insertion tube by electrically connecting an intelligent control box with a micro pressure sensor, a first pressure sensor, a second pressure sensor, a flow meter, a main flow pump, a pulsating flow generation module, and a strain monitoring device. Combined with the intelligent control box, it dynamically adjusts the flow rate step according to real-time pressure drop changes, analyzes the internal pressure field distribution of the insertion tube, the corresponding flow rate pressure drop curve, and structural deformation, and can output and intuitively display the analysis diagram.

[0024] Second, this invention simulates the ECMO cannula's operating environment through a visual enclosure, including the liquid environment, temperature environment, and non-Newtonian fluid characteristics simulated by a viscosity control system. Meanwhile, the movable bracket can load cannulas of different specifications, and the miniature pressure sensor is adapted to cannulas of different diameters, enabling testing of cannulas of multiple sizes. It also avoids interference factors from the contact surface with the enclosure, making the cannula testing more accurate.

[0025] Third, this invention utilizes a strain monitoring device to monitor the deformation of the intubation cannula under different flow rates to assess its structural stability. Through the CFD digital model correction function of the intelligent control box, performance curves under different conditions can be predicted using only a small amount of test data, reducing the number of tests and improving testing efficiency. The ingenious structural design and functional integration of the ECMO intubation cannula performance testing equipment enable testing not only of cannulas without side holes but also those with side holes, demonstrating high versatility and intelligence. Attached Figure Description

[0026] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1This is a schematic diagram of the structure of an ECMO cannulation performance testing device provided in an embodiment of the present invention;

[0028] Figure 2 A control circuit logic diagram of an ECMO cannulation performance testing device provided in an embodiment of the present invention;

[0029] In the diagram: 1. Visualized housing; 1-1. First pressure sensor; 1-2. Second pressure sensor; 1-3. Miniature pressure sensor; 1-4. Strain monitoring device; 1-5. Movable support; 1-6. Inlet; 1-7. Pulsating flow generation module; 1-8. Main flow pump; 1-9. Flow meter; 1-10. Outlet; 1-11. Water valve; 1-12. Temperature control module; 1-13. Viscosity control system; 1-14. ECMO cannula; 2. Intelligent control box; 2-1. Water pump switch button; 2-2. Uniform flow increase mode button; 2-3. Pulsating flow mode button; 2-4. Pressure drop indicator light; 2-5. Deformation indicator light; 2-6. USB interface; 2-7. Touch screen. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0031] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this invention is for describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. Example 1

[0032] Please see Figure 1 This embodiment proposes an ECMO cannula performance testing device, including a visualization chamber 1, a first pressure sensor 1-1, a second pressure sensor 1-2, a miniature pressure sensor 1-3, a strain monitoring device 1-4, a water inlet 1-6, a pulsating flow generation module 1-7, a main flow pump 1-8, a flow meter 1-9, a water outlet 1-10, a water valve 1-11, and an intelligent control box 2. The ECMO cannula 1-14 under test, located inside the visualization chamber 1, is sequentially connected to the second pressure sensor 1-2, the water inlet 1-6, the pulsating flow generation module 1-7, the main flow pump 1-8, the flow meter 1-9, and the water outlet 1-10 through a circulation pipeline, forming a continuous liquid path. Wherein:

[0033] The first pressure sensor 1-1 is used to test water pressure; the second pressure sensor 1-2 is used to test the pressure of the fluid flowing out of the cannula; the miniature pressure sensor 1-3 is used to test the pressure value at different locations inside the cannula, and then draw a cloud map of the pressure field distribution inside the cannula; the strain monitoring device 1-4 monitors the deformation degree of the cannula at different flow rates by attaching miniature strain gauges to the outer wall of the cannula, and evaluates its structural stability; the inlet 1-6 connects to the ECMO cannula 1-14 and injects fluid; the pulsating flow generation module 1-7 includes a servo piston pump, which is used to simulate pulsating blood flow under different heart rate and blood pressure waveforms; the main flow pump 1-8 is used to adjust the flow rate of the fluid flowing through the circulation pipeline; the flow meter 1-9 is used to test the flow rate value of the fluid flowing out of the cannula; the outlet 1-10 connects to the ECMO cannula 1-14 and discharges fluid; the water valve 1-11 is set on the side wall of the visualization box 1 to control the stopping and starting of fluid injection.

[0034] It should be noted that the bottom of the visualization box 1 is provided with a concave groove, on which multiple movable brackets 1-5 are installed. The brackets can be used to place the ECMO cannula 1-14, the first pressure sensor 1-1 and the second pressure sensor 1-2. The three are not only located on the same horizontal plane, but also can avoid contact with the bottom of the box, thus avoiding affecting the measurement of liquid flow rate, pressure and deformation values.

[0035] In addition, this ECMO cannula performance testing equipment is equipped with a temperature control module 1-12 and a viscosity control system 1-13. The temperature control module 1-12 can control the liquid temperature, thereby simulating blood temperature; the viscosity control system 1-13 can adjust the fluid viscosity in real time according to the shear rate, simulating the non-Newtonian fluid characteristics of blood. The liquid environment inside the visualization chamber 1 includes glycerol, water, phosphate buffer solution, and suspended particulate solution, all of which can simulate the liquid environment of blood vessels. The miniature pressure sensor 1-3 can be adapted to cannulas with diameters of 8-30 Fr. The contacts of the miniature pressure sensor 1-3 are located on the inner surface of the cannula at different positions. The main flow pump 1-8 is used to regulate the flow rate of the liquid flowing through the circulation pipeline, with a flow rate adjustment accuracy of 0.01 L / min and an adjustable flow rate range of 0~8.00 L / min.

[0036] The intelligent control box 2 controls the main flow pump 1-8 and the pulsating flow generation module 1-7 to adjust the flow rate of the entire circulation pipeline. The micro pressure sensor 1-3, flow meter 1-9, first pressure sensor 1-1, second pressure sensor 1-2 and strain monitoring device 1-4 feed information back to the intelligent control box 2 through the circuit system for processing, thereby obtaining the internal pressure field distribution cloud map, flow pressure drop curve and structural deformation analysis diagram of the ECMO cannula 1-14. Moreover, its intelligent alarm function can compare the pressure drop value and deformation value of the cannula according to the preset safety value to determine whether the cannula under test is qualified.

[0037] In the aforementioned ECMO cannula performance testing equipment, the intelligent control box 2 includes a box frame. The box frame is equipped with a water pump switch button 2-1, a uniform flow increase mode button 2-2, a pulsating flow mode button 2-3, a pressure drop indicator light 2-4, a deformation indicator light 2-5, a USB flash drive interface 2-6, and a touch screen 2-7. The box frame contains a control circuit, which is electrically connected to a heat dissipation device, a PLC, a DAQ data acquisition card, a PC host computer, a stepper motor driver, a main flow pump 1-8, a pulsating flow generation module 1-7, a first pressure sensor 1-1, a second pressure sensor 1-2, a flow meter 1-9, a miniature pressure sensor 1-3, a strain monitoring device 1-4, the water pump switch button 2-1, the uniform flow increase mode button 2-2, the pulsating flow mode button 2-3, the pressure drop indicator light 2-4, the deformation indicator light 2-5, the USB flash drive interface 2-6, and the touch screen 2-7. The PLC indirectly controls the main flow pumps 1-8 by controlling the stepper motor driver. It can adjust the flow rate increase rate to an accuracy of 0.01L / min / s and supports AI-based intelligent testing functions. It dynamically adjusts the flow step according to real-time pressure drop changes and automatically refines the step size at the pressure drop threshold, achieving a more intelligent and accurate flow testing function.

[0038] Please see Figure 2 The intelligent control box 2 is equipped with a circuit control system including a PLC, a PC host computer, a touch screen, a DAQ acquisition card, and a temperature control module 1-12. The PLC is electrically connected to the PC host computer, the viscosity control system 1-13, the first pressure sensor 1-1, the second pressure sensor 1-2, the pulsating flow generation module 1-7, the main flow pump 1-8, and the flow meter 1-9. The PC host computer is electrically connected to the DAQ acquisition card, and the DAQ acquisition card is electrically connected to the miniature pressure sensor 1-3. The miniature pressure sensor 1-3, the first pressure sensor 1-1, and the second pressure sensor 1-2 are set in the visualization box 1 to detect the tube under test. The temperature control module 1-12, the viscosity control system 1-13, and the flow meter are all connected to the visualization box 1. The intelligent control box 2 can process test data in real time, draw cloud maps of the internal pressure field distribution of the cannula, flow rate and pressure drop curves, and structural deformation analysis diagrams, and supports reading and exporting historical measurement data; at the same time, it integrates CFD digital model correction function, which can optimize model parameters in real time using test data, and predict cannula performance under different flow rates and viscosities with a small amount of test data.

[0039] It should be noted that the ECMO cannula 1-14 to be tested is Fr26, with an 8×8 external connector and a tube length of 380mm, and is a cannula with side holes. The tip of the cannula is connected to the circulation tubing, then placed and fixed on the movable bracket 1-5. The first pressure sensor 1-1 is fixed to the two movable brackets 1-5 on one side of the water valve 1-11, and the second pressure sensor 1-2 is fixed to the two movable brackets 1-5 on the side near the inlet 1-6. Four miniature pressure sensors 1-3 are then connected inside the cannula, located inside the four side holes. Miniature strain gauges are attached to the outer wall of the cannula to monitor the deformation of the cannula at different flow rates. The ECMO cannula 1-14 can be with or without side holes.

[0040] The liquid in the visualization chamber 1 is glycerol, which is injected into the chamber through water valve 1-11. Once the liquid level reaches the designated position, water valve 1-11 is closed to stop the injection. The temperature control module 1-12 is turned on and set to 37℃ to heat the glycerol and maintain that temperature. The viscosity control system 1-13 is turned on and set to an initial viscosity of 3 mPa·s, allowing it to adjust the viscosity in real time according to the shear rate. The arterial flow generation module can simulate a pulsating waveform with a heart rate of 20-200 beats / minute, measuring the deformation and pressure values ​​of the cannula under dynamic conditions. The viscosity control system 1-13 adjusts the fluid viscosity range from 1 to 8 mPa·s, simulating the rheological characteristics of different blood types. The intelligent alarm function can be used to determine whether the pressure drop and deformation of the cannula are within acceptable limits. If acceptable, the device displays a green light; if unacceptable, the device displays a red light. Example 2

[0041] A testing method for an ECMO cannulation performance testing device includes the following steps:

[0042] In this embodiment, the ECMO cannula 1-14 with side holes, featuring Fr26 specification, 8×8 external connector, and a body length of 380mm, installed as in Embodiment 1, is used. Glycerin is injected and the valve is closed. The temperature and initial viscosity are set, specifically including:

[0043] Connect the tube to be tested to the pipeline at the front end of the second pressure sensor 1-2, and then place it horizontally on the movable bracket 1-5 in the groove; place the first pressure sensor 1-1 on the movable bracket 1-5, at the same horizontal line as the tube; connect the miniature pressure sensor 1-3 to the tube; attach the miniature strain gauge device to the outer wall of the tube.

[0044] Open the valve of the visualization chamber 1 to begin liquid filling. Stop filling and close the valve when the liquid level in the visualization chamber 1 reaches the appropriate level. Open the temperature control module 1-12 to adjust the liquid temperature to a suitable temperature that simulates human blood. Open the viscosity control system 1-13 to set the initial viscosity parameters according to the test requirements.

[0045] Turn on the power switch. The device will start and the main page will be displayed on touchscreen 2-7. Insert the USB flash drive into USB flash drive interface 2-6. Set the voltage drop value of the intelligent alarm function module to 20% and the deformation value to 1%. Adjust the current speed to 1L / min, the speed increase control to 0.1L / min / s, and the maximum speed to 8L / min. At the same time, enable the AI-based intelligent testing function.

[0046] Connect the USB flash drive to USB port 2-6 and click the "Start Data Recording" function on the screen. Turn on the water pump switch button 2-1 and the uniform flow increase mode button 2-2. The liquid in the visualization chamber 1 gradually increases at an initial flow rate of 1L / min in uniform flow increase mode. During the test, the pressure drop indicator 2-4 and the deformation indicator 2-5 are green, indicating that the pressure drop and deformation values ​​of the tube under test are qualified. After the flow rate reaches 8L / min, the flow rate stops increasing and maintains a stable flow circulation state. Turn off the water pump switch button 2-1 and the uniform flow increase mode button 2-2. The internal pressure field distribution cloud map of the tube, the corresponding flow rate-pressure drop curve relationship graph, and the structural deformation analysis graph can be viewed on the touch screen 2-7. At the same time, the intelligent control box 2 will use the test data to correct the CFD digital model, and the predicted performance curves under different conditions can be viewed. The test data can be exported via USB flash drive for further in-depth analysis. Example 3

[0047] A testing method for an ECMO cannulation performance testing device includes the following steps:

[0048] In this embodiment, the ECMO cannula 1-14 with side holes, which is of specification Fr26, external connector 8×8, and tube length of 380mm, installed in Embodiment 1, is used to inject glycerol and close the valve, and the temperature and initial viscosity are set.

[0049] Turn on the power switch. The device will start and the main page will be displayed on touchscreen 2-7. Insert the USB flash drive into USB flash drive port 2-6. On touchscreen 2-7, set the simulated heart rate of the pulse flow module to 75 beats / minute; set the deformation value of the intelligent alarm function module to 1%; adjust the current speed to 3L / min, the speed increase control to 0L / min / s, and the maximum speed to 0L / min; and enable the AI-based intelligent testing function.

[0050] Connect the USB flash drive to USB port 2-6 and click "Enable Data Recording" on the screen. Turn on the water pump switch button 2-1 and the pulsating flow mode button 2-3. The liquid in the visualization chamber 1 exhibits a pulsating, circulating flow in pulsating flow mode. During the test, the deformation value indicator light 2-5 will be red, indicating that the deformation value of the tube under test is unqualified under the pulsating flow module. Turn off the water pump switch button 2-1 and the pulsating flow mode button 2-3. The tube structure deformation analysis diagram can be viewed on the touch screen 2-7. After acquiring relevant data using the USB flash drive, in-depth analysis of the test data of the unqualified tubes can be performed. Example 4

[0051] To improve overall testing efficiency, this embodiment further introduces three core calculation formulas: pressure field distribution interpolation calculation, dynamic flow-pressure drop relationship modeling, and structural deformation risk index assessment. All three are executed by the PC host computer of the intelligent control box 2 using Python or MATLAB algorithms, with data sources being real-time sensor output or preprocessed datasets. For dynamic simulation environments, such as AI-optimized flow adjustment and CFD model calibration, the calculation results are directly used to generate visualizations and performance evaluations, specifically including:

[0052] 1. Pressure field distribution interpolation calculation, used to generate pressure field distribution contour maps: In the formula: P(x, y) is the interpolated pressure value at any position (x, y) inside the cannula, and the output is the full-field distribution data; wi is the weighting coefficient, calculated based on the distance between the sensor position and the target point; Pi is the measured value of the i-th micro pressure sensor, and the data source is real-time acquisition; n is the number of sensor points; α is the fluid dynamics CFD model correction factor, used to correct simulation errors, obtained by training from historical test data, and in this example α=0.3; CFD(x, y) is the pressure Laplace operator in the fluid dynamics model, and the data source is the baseline CFD model pre-installed in the intelligent control box 2. The PC host computer uses the calculation results of this formula to draw a pressure field distribution cloud map, identify high-pressure areas such as those near the side holes, and optimize the side hole design to reduce the risk of hemolysis. The intelligent control box 2 also uses the pressure field data to correct the CFD model parameters for subsequent prediction.

[0053] II. Dynamic flow-pressure drop relationship modeling, used to generate flow-pressure drop curves: In the formula: ΔPd is the dynamic pressure drop, i.e. the pressure difference before and after cannulation; Q is the real-time flow rate; The rate of change of flow rate; The pulsation term simulates the effect of heart rate, where A is the pulsation amplitude, f is the heart rate, and t is time; K1, K2, and K3 are model coefficients representing the inherent resistance characteristics of the cannula. The intelligent control box 2 executes this formula to calculate and plots a flow-pressure drop curve, revealing the resistance fluctuations under pulsating flow. In this embodiment, when the flow rate increases to a certain value, the formula identifies… Increased flow rate caused a surge in pressure drop, triggering optimization: the PLC automatically slowed down the flow rate increase and refined the test step size at the pressure drop threshold. After the graph was output, engineers analyzed the resistance fluctuation characteristics to assess the stability of the cannula under pathological heart rates.

[0054] III. Structural Deformation Risk Index Assessment, used to produce structural deformation analysis diagrams. In the formula: Rs is the deformation risk index, and the higher the value, the greater the risk of structural failure; The measured strain value is obtained from the strain gauge output of strain monitoring devices 1-4. In this embodiment, the average value of the middle section of the insertion tube is taken. The reference strain threshold is defined by the tubing material property library; σ is the stress fluctuation standard deviation, calculated from the strain data time series, reflecting the fluctuation intensity under pulsating flow; β and γ are weighting coefficients, emphasizing the influence of static deformation and dynamic fluctuation. In this example, β=0.7 and γ=0.3. The PC host computer performs the calculation, generates a structural deformation analysis diagram, displays high-risk areas, and quantifies the degree of deformation. In this embodiment, when the flow rate reaches 6.0 L / min, and the Rs exponent locally rises to a certain value, the equipment suggests reducing the upper limit of the test flow rate accordingly. The intelligent control box 2 combines this result with the pressure field distribution interpolation output to provide a comprehensive structural stability report for product improvement.

[0055] Upon completion of the test, the intelligent control box 2 integrates the results of the three formulas: a pressure field cloud map displays the high-pressure zone in the side orifice, the flow-pressure drop curve reveals dynamic resistance characteristics, and the deformation analysis diagram identifies risk points. In the output report, engineers use the pressure field data to optimize the CFD model for new cannulation prediction, adjust heart rate simulation parameters based on the pressure drop curve, and improve material selection using a risk index. All data is exportable. This embodiment demonstrates the synergistic application of the equipment in multi-parameter dynamic testing; the formula calculation results directly drive test optimization and design decisions, improving test accuracy and efficiency.

[0056] The above solution achieves intelligent data processing and optimization. By integrating AI algorithms and CFD model correction, it enables dynamic optimization of the testing process. For example, it automatically refines the flow step at the pressure drop threshold, reducing the number of invalid tests. The synchronous processing capability of the intelligent control box avoids the data silo problem in traditional methods, improving testing efficiency. In addition, the solution enables comprehensive and intuitive performance evaluation. Based on multi-dimensional data such as pressure field, flow pressure drop, and deformation, it generates visualized output cloud maps or curves. Engineers can intuitively identify bottlenecks in cannulation performance, such as high resistance areas or structural risk points. Compared with traditional point-based data reports, this is more conducive to optimizing product design.

[0057] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative and not exhaustive. All modifications within the scope of this invention or its equivalents are included in this invention.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. An ECMO cannulation performance testing device, characterized in that, include: The visualization box (1) and the intelligent control box (2) are used to install the tube to be tested and provide a liquid environment. The tube is connected to the inlet (1-6), the pulsating flow generation module (1-7), the main flow pump (1-8), the flow meter (1-9) and the outlet (1-10) in the visualization box (1) in sequence through a circulation pipeline to form a continuous liquid path. The visualization box (1) is also equipped with a first pressure sensor (1-1) for testing the water pressure of the tube, a second pressure sensor (1-2) for testing the pressure of the liquid flowing out of the tube, and a micro pressure sensor for testing the pressure values ​​at different positions in the tube. Force sensor (1-3) and strain monitoring device (1-4) for monitoring the degree of cannula deformation. The intelligent control box (2) regulates the liquid flow and pulsation state of the continuous liquid passage by controlling the main flow pump (1-8) and the pulsating flow generation module (1-7). The micro pressure sensor (1-3), flow meter (1-9), first pressure sensor (1-1), second pressure sensor (1-2) and strain monitoring device (1-4) feed the detection information back to the intelligent control box (2) through the circuit system to perform internal pressure field distribution, flow pressure drop and structural deformation analysis of the cannula, and output analysis diagram. The analysis of pressure field distribution, flow rate pressure drop, and structural deformation inside the cannula includes: pressure field distribution interpolation calculation, dynamic flow rate pressure drop relationship analysis, and structural deformation risk index assessment. The pressure field distribution interpolation calculation formula is as follows: In the formula: P(x,y) is the interpolated pressure value at any position (x,y) inside the cannula; wi is the weighting coefficient; Pi is the measured value of the i-th micro pressure sensor; n is the number of sensor points; α is the fluid dynamics model correction factor; CFD(x,y) is the pressure Laplace operator in the fluid dynamics model; The formula for analyzing the dynamic flow-pressure drop relationship is as follows: In the formula: ΔPd is the dynamic pressure drop; Q is the real-time flow rate; t is the rate of change of flow rate; A is the pulse amplitude; f is the heart rate; t is the time. K1, K2, and K3 are model coefficients.

2. The ECMO cannulation performance testing equipment according to claim 1, characterized in that, The visualization box (1) is connected to a temperature control module (1-12) for controlling the liquid temperature and a viscosity control system (1-13) for adjusting the fluid viscosity.

3. The ECMO cannulation performance testing equipment according to claim 1, characterized in that, The inner bottom of the visualization box (1) is provided with a concave groove, and multiple movable brackets (1-5) are installed on the concave groove for placing the ECMO cannula (1-14), the first pressure sensor (1-1), and the second pressure sensor (1-2) on the same horizontal plane.

4. The ECMO cannulation performance testing equipment according to claim 1, characterized in that, The intelligent control box (2) is equipped with a control circuit containing a PLC, and the control circuit is electrically connected to a micro pressure sensor (1-3), a main flow pump (1-8), a flow meter (1-9), a pulsating flow generation module (1-7), a first pressure sensor (1-1), a second pressure sensor (1-2), and a strain monitoring device (1-4). The surface of the intelligent control box (2) is equipped with a water pump switch button (2-1), a uniform flow increase mode button (2-2), a pulsating flow mode button (2-3), a pressure drop indicator light (2-4), a deformation indicator light (2-5), a USB flash drive interface (2-6), and a touch screen (2-7), which are electrically connected to the control circuit.

5. The ECMO cannulation performance testing equipment according to claim 1, characterized in that, The liquid environment inside the visualization box (1) includes at least one of the following: glycerol, water, phosphate buffer solution, and suspended particulate solution.

6. The ECMO cannulation performance testing equipment according to claim 1, characterized in that, There are multiple miniature pressure sensors (1-3), and the sensor contacts are located on the inner surface of the cannula.

7. The ECMO cannulation performance testing equipment according to claim 1, characterized in that, The formula for assessing the structural deformation risk index is as follows: In the formula: Rs is the deformation risk index. These are the measured strain values; σ is the reference strain threshold; σ is the standard deviation of stress fluctuation; β and γ are weighting coefficients.

8. A testing method for an ECMO cannula performance testing device, implemented based on the ECMO cannula performance testing device as described in any one of claims 1-7, characterized in that, include: S1: Connect the tube to be tested to the pipeline at the front end of the second pressure sensor (1-2), and then place it horizontally on the movable bracket (1-5) in the concave groove at the bottom of the visualization box (1); place the first pressure sensor (1-1) on the movable bracket (1-5) and place it on the same horizontal line as the tube; connect the miniature pressure sensor (1-3) to the tube; attach the strain monitoring device (1-4) to the outer wall of the tube. S2: Open the water valve (1-11) of the visualization chamber (1) to fill the liquid. When the liquid in the visualization chamber (1) reaches the specified capacity, close the water valve (1-11), open the temperature control module (1-12), adjust the liquid temperature to the appropriate temperature that simulates human blood, open the viscosity control system (1-13), and set the initial viscosity parameters according to the test requirements. S3: Turn on the intelligent control box (2), set the parameters of the pulsating flow generation module through the touch screen (2-7) to simulate different pulsating blood flow scenarios, adjust the current speed, speed increase control, and maximum speed to the specified value; select the uniform flow mode or pulsating flow mode, turn on the water pump switch button (2-1), and the liquid will start to circulate according to the current settings; S4: Connect the USB flash drive to the USB flash drive interface (2-6), click the touch screen (2-7) to start data recording. In the uniform flow mode, turn on the self-increase button. The liquid flow rate changes according to the currently set growth rate value and adjusts the flow rate step according to the real-time pressure drop changes. In the pulsating flow mode, the liquid exhibits a pulsating flow state. S5: After the flow rate circulates and stabilizes and reaches the preset maximum speed, turn off the water pump switch button (2-1) to end the uniform flow increase mode; after the test data is collected, turn off the water pump switch button (2-1) to end the pulsating flow mode. S6: On the touch screen (2-7), you can view the internal pressure field distribution cloud map of the cannula, the corresponding flow rate pressure drop curve relationship diagram, the structural deformation analysis diagram, and the flow distribution ratio analysis results of the main hole and each side hole of the cannula with side holes; at the same time, the intelligent control box (2) uses the test data to correct the CFD digital model and displays the prediction performance curve under different conditions. The test data is exported via USB flash drive for further in-depth analysis.

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