Double-ring circulation system for in-vitro drainage test of extracorporeal membrane pulmonary oxygenation vein drainage tube

Abstract

The invention discloses a double-ring circulation system for in-vitro drainage test of an in-vitro membrane pulmonary oxygenation vein drainage tube, and belongs to the technical field of medical engineering. According to the invention, the blood circulation simulation module can accurately load and simulate the blood flow waveform of the inferior vena cava of a human body under physiological or pathological conditions, and the vein drainage module can effectively simulate the drainage effect of extracorporeal membrane oxygenation vein drainage and is used for evaluating the drainage effect. According to the double-circulation system, by replacing the rigid / elastic vein simulation tube, the influence rule of the drainage mode of the vein drainage tube on the drainage efficiency and the vein adherence problem is explored. And a more scientific and effective in-vitro test evaluation experiment platform is provided for effectively evaluating the hydrodynamic performance when the drainage hole of the vein drainage tube is blocked and improving the drainage efficiency of the vein drainage tube.

Description

Technical Field

[0001] The present invention belongs to the field of medical engineering technology and relates to a double-loop circulation system for in vitro drainage testing of extracorporeal membrane oxygenation venous drainage tubes. The present invention is an in vitro testing and evaluation system for the wall obstruction of the drainage holes of venous drainage tubes designed based on hemodynamic principles, clinical operation simulation, signal monitoring technology and automatic control technology. Background Art

[0002] Extracorporeal membrane oxygenation (ECMO), also known as an extracorporeal artificial heart and lung, is a critical care emergency treatment technology that supports the breathing and circulation of patients with severe cardiopulmonary failure through an extracorporeal circulation device.

[0003] The working principle of ECMO is to draw the patient's blood out of the body through the venous drainage tube, drive it into the oxygenator outside the body through a centrifugal pump, and then return it to the patient's body through the arterial cannula. During the ECMO blood drainage process, an important problem encountered in clinical practice is that the drainage holes of the venous drainage tube are blocked by the wall, which in turn causes the tube shaking phenomenon. The deformation and movement of the venous blood vessel wall will cause unstable vibration of the cannula, further causing blockage of the drainage pipeline, thereby significantly reducing the blood circulation flow, resulting in the inability to carry out normal treatment, and even causing other organs of the patient to face a huge risk of ischemia and hypoxia, seriously affecting the patient's life. The main reason for the blockage of the drainage holes of the venous drainage tube is that the human body's venous walls are very soft. Under insufficient capacity or large negative pressure, the venous wall will collapse and wrap around the venous drainage tube, blocking the drainage holes of the venous drainage tube and affecting the drainage efficiency.

[0004] When selecting a real animal model for in vivo experiments, strict surgical operations are required, including establishing drainage pathways, performing appropriate anesthesia and analgesia, etc., to ensure the safety of the animals during the experiment, and to avoid the occurrence of thrombosis or bleeding complications. In vitro testing can achieve more flexible control, improve the controllability and repeatability of the experiment, save time compared to in vivo experiments, reduce experimental costs, and reduce possible ethical and safety risks during the experiment. The pulsatile blood pump output flow used in the early in vitro test system failed to meet the high flow requirements of ECMO, and the in vitro fluid dynamics model currently used to test the performance of venous drainage tubes is to place the venous drainage tube in a test container for experimentation, using a single rigid simulation tube for testing, without evaluating the effects of different types of cannulation and drainage methods on the anti-adhesion function. The test container used cannot simulate the blood flow of the inferior vena cava in the human body, and does not accurately simulate the real environment in the body, so it cannot reflect the situation of the drainage hole of the venous drainage tube being blocked by the wall in clinical practice, and cannot effectively evaluate the fluid dynamics performance of the drainage hole of the venous drainage tube when it is blocked. Therefore, there is an urgent need for an in vitro circulation test system that can simulate the in vivo blood flow circulation and the drainage process of the venous drainage tube.

[0005] The present invention constructs an in vitro blood circulation system that can accurately and truly simulate the blood flow environment of the inferior vena cava in vivo. Combined with elastic tube materials that simulate the mechanical properties of blood vessels, in vitro testing and evaluation of the drainage efficiency of venous drainage tubes under different blood flow conditions are performed, which has important clinical significance and practical value for improving ECMO venous drainage efficiency, optimizing venous drainage tube design, and improving clinical surgical operations. Summary of the invention

[0006] The purpose of the present invention is to design and construct a double-loop circulation system for in vitro drainage testing of extracorporeal membrane oxygenation venous drainage tubes, which can simulate the blood flow circulation of the inferior vena cava in vitro and the drainage process of the venous drainage tube. In addition, a rigid venous simulation tube is used to carry out drainage experiments on venous drainage tubes to test the effects of venous drainage tubes and drainage methods on drainage efficiency, and a venous simulation tube with in vivo venous elastic characteristics is used to carry out drainage experiments on venous drainage tubes to test the effects of venous drainage tubes and drainage methods on drainage efficiency and anti-adhesion function.

[0007] The technical solution of the present invention is as follows:

[0008] A double-loop circulation system for an ex vivo drainage test of an extracorporeal membrane oxygenation venous drainage tube comprises a blood circulation simulation module and a venous drainage circulation module.

[0009] The blood circulation simulation module includes: a blood circulation circuit L B and a blood flow control loading and signal detection unit. The blood circulation circuit L BThe invention comprises: a first programmable flow pump A-1, a Y-shaped three-way pipe A-2, an inferior vena cava simulation tube A-3, a liquid storage bottle A-4 and a lifting platform A-5. The first programmable flow pump A-1 drives the solution in the liquid storage bottle A-4 fixed on the lifting platform A-5 through flow waveform programming control, pumps the solution into the first inlet of the Y-shaped three-way pipe A-2 through the catheter, flows through the inferior vena cava simulation tube A-3, and finally flows back to the liquid storage bottle A-4. The inferior vena cava simulation tube A-3 is made of catheters of different materials and different rigidities according to the size, shape and test conditions of the human inferior vena cava; the liquid storage bottle A-4 is fixed on the lifting platform A-5, which is higher than the common horizontal plane where the first programmable flow pump A-1, the Y-type three-way pipe A-2 and the inferior vena cava simulation tube A-3 are located; the lifting platform A-5 can adjust the vertical height h of the liquid storage bottle A-4, and use Pascal's law p=ρgh to provide a basic pressure value p by adjusting the height h to simulate the basic pressure of the inferior vena cava, where ρ represents the density of the solution and g represents the acceleration of gravity.

[0010] The blood flow control loading and signal detection unit ( Figure 2 ) includes: a main control host computer C-1, a first single-chip microcomputer and a driving module C-2, a direct current power supply C-3, and a first flow sensor C-4. The first single-chip microcomputer and the driving module C-2 are composed of a single-chip microcomputer and a motor driving module. The main control host computer C-1 inputs the instruction into the single-chip microcomputer in the first single-chip microcomputer and the driving module C-2 through the communication wire. The first flow sensor C-4 is arranged at the outlet pipe of the first programmable flow pump A-1, and converts the flow information into flow velocity information through the formula: flow velocity V = flow rate Q / pipe diameter cross-sectional area S, and then passes through the communication wire to the single-chip microcomputer in the first single-chip microcomputer and the driving module C-2 and transmits it back to the main control host computer C-1; the direct current power supply C-3 provides a stable power electrical signal to the motor driving module in the first single-chip microcomputer and the driving module C-2, and after the action of the motor driving module, it is loaded on the first programmable flow pump A-1 to generate a stable motor torque and speed. Furthermore, the blood flow control loading and signal detection unit adopts a proportional-integral-differential control method. The first flow sensor C-4 transmits the flow rate information back to the first single-chip microcomputer and the single-chip microcomputer in the driving module C-2. The single-chip microcomputer continuously fits the measured flow rate information with the input human inferior vena cava simulation waveform, outputs a continuously corrected pulse width modulation signal, and loads it to the first programmable flow pump A-1 through the driving module to accurately output the set flow rate waveform.

[0011] The venous drainage circulation module includes: a venous drainage circulation loop L D , drainage control and signal detection unit. The venous drainage circulation loop L DIt includes: a second programmable flow pump B-1 and a venous drainage tube B-2. The second programmable flow pump B-1 controls the solution in the venous drainage tube B-2 which is drawn out from the inferior vena cava simulation tube A-3 and extends to the second inlet of the Y-type three-way tube A-2 through flow waveform programming, and draws the solution from the inferior vena cava simulation tube A-3 through a catheter to connect to a liquid storage bottle A-4 fixed on a lifting platform A-5. Furthermore, the venous drainage tube B-2 adopts venous drainage tubes with different clinical structural parameters such as the number of side holes, the number of side holes, the spatial distribution of side holes, etc., to test the drainage efficiency and wall adhesion of different venous drainage tubes.

[0012] The drainage control and signal detection unit ( Figure 2 ) includes: a second single-chip computer and a driving module D-1, a second flow sensor D-2, a wireless pressure sensor D-3, and a wireless flow sensor D-4. The second single-chip computer and the driving module D-1 are composed of a single-chip computer and a motor driving module. The main control host computer C-1 inputs the instruction into the single-chip computer in the second single-chip computer and the driving module D-1 through the communication wire. The second flow sensor D-2 is set at the outlet of the venous drainage tube B-2, and the flow information is converted into flow velocity information through the formula: flow velocity V = flow rate Q / tube diameter cross-sectional area S. After that, it is transmitted back to the main control host computer C-1 through the communication wire to the single-chip computer in the second single-chip computer and the driving module D-1; the wireless pressure sensor D-3, the wireless pressure sensor D-4, the wireless pressure sensor D-5, the wireless pressure sensor D-6, the wireless pressure sensor D-7, the wireless pressure sensor D-8, the wireless pressure sensor D-9, the wireless pressure sensor D-10, the wireless pressure sensor D-111, the wireless pressure sensor D-12, the wireless pressure sensor D-13, the wireless pressure sensor D-14, the wireless pressure sensor D-15, the wireless pressure sensor D-16, the wireless pressure sensor D-17, the wireless pressure sensor D-18, the wireless pressure sensor D-219, the wireless pressure sensor D-220, the wireless pressure sensor D-221, the wireless pressure sensor D-222, the wireless pressure sensor D-33, the wireless pressure sensor D-44. The flow sensor D-4 is arranged at the part of the venous drainage tube B-2 located at the inferior vena cava simulation tube A-3, and the drainage flow rate and pressure information at the venous drainage tube B-2 are transmitted back to the main control host computer C-1 in real time. The changes in the drainage flow rate and pressure information reflect the drainage efficiency and the wall adhesion. The DC power supply C-3 provides a stable power electrical signal to the motor drive module in the second single-chip microcomputer and the drive module D-1, and after the action of the motor drive module, it is loaded on the second programmable flow pump B-1 to generate a stable motor torque and speed. Further, the drainage control and signal detection unit adopts a proportional-integral-differential control method. The second flow sensor D-2 transmits the flow rate information back to the single-chip microcomputer in the second single-chip microcomputer and the drive module D-1. The single chip continuously fits the measured flow rate information with the input venous drainage waveform, and outputs a continuously corrected pulse width modulation signal, which is loaded on the second programmable flow pump B-1 through the drive module to accurately output the set flow rate waveform.

[0013] Furthermore: the selection of the inferior vena cava simulation tube A-3 is specifically as follows: an elastic hose with the same mechanical properties as the human inferior vena cava is used to test the drainage efficiency and wall adhesion during the drainage process; a transparent rigid tube is used to eliminate the influence of wall adhesion during the drainage process, so as to test the drainage efficiency alone.

[0014] Furthermore, a double-loop circulation system for in vitro drainage test of extracorporeal membrane oxygenation venous drainage tube was used to explore the effect of venous drainage tube structure and drainage method on drainage efficiency and venous wall adhesion. The experimental steps are as follows:

[0015] Step 1: The inferior vena cava simulation tube A-3 uses a rigid tube to carry out drainage experiments of venous drainage tubes under different pressure conditions to test the influence of the structure and drainage method of the venous drainage tube on the drainage efficiency;

[0016] Step 2: Use a venous simulation tube with the elastic characteristics of in vivo veins to carry out drainage experiments of venous drainage tubes under different pressure conditions to test the effects of venous drainage tube structure and drainage method on drainage efficiency and anti-adhesion function.

[0017] Beneficial effects of the present invention: The present invention can accurately load and simulate the blood flow waveform of the inferior vena cava of the human body under physiological or pathological conditions through the blood circulation simulation module, and the venous drainage module can provide a stable and continuous drainage effect. The dual circulation system of the present invention replaces the rigid / elastic venous simulation tube to explore the influence of the drainage method of the venous drainage tube on the drainage efficiency and the problem of venous adhesion. In order to effectively evaluate the fluid dynamics performance of the drainage hole of the venous drainage tube when it is blocked, and to improve the drainage efficiency of the venous drainage tube, a more scientific and effective in vitro test and evaluation experimental platform is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the structural diagram of the blood circulation simulation module and the venous drainage circulation module; B is the blood circulation circuit; L D It is the venous drainage circulation loop.

[0019] Figure 2 It is a structural diagram of the double-loop circulation system for the ex vivo drainage test of the extracorporeal membrane oxygenation venous drainage tube.

[0020] In the figure: A-1 is a programmable flow pump 1, A-2 is a Y-type three-way tube, A-3 is an inferior vena cava simulation tube, A-4 is a liquid storage bottle, A-5 is a lifting platform, B-1 is a programmable flow pump 2, B-2 is a venous drainage tube, C-1 is a main control host computer, C-2 is a single-chip microcomputer and drive module 1, C-3 is a DC power supply, C-4 is a flow sensor 1, D-1 is a single-chip microcomputer and drive module 2, D-2 is a flow sensor 2, D-3 is a wireless pressure sensor, and D-4 is a wireless flow sensor. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0022] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0023] If it is specifically set according to actual construction requirements, no specific restrictions will be made in this application. A dual-loop circulation system for ex vivo drainage testing of extracorporeal membrane oxygenation venous drainage tubes, characterized by including: a blood circulation loop and a venous drainage circulation module. The blood circulation loop (I) includes: a first programmable flow pump A-1, a Y-shaped three-way pipe A-2, an inferior vena cava simulation tube A-3, a liquid storage bottle A-4, a lifting platform A-5, a main control host computer C-1, a first single-chip microcomputer and a drive module C-2, a DC power supply C-3, and a first flow sensor C-4. The venous drainage module includes: a second programmable flow pump B-1, a venous drainage tube B-2, a second single-chip microcomputer and a drive module D-1, a second flow sensor D-2, a wireless pressure sensor D-3, and a wireless flow sensor D-4. Before the drainage test begins, place the device as follows: Figure 1 , Figure 2 Connections shown.

[0024] The working process of the double circulation system is:

[0025] The main control host computer C-1 is connected to the first single-chip microcomputer and the drive module C-2 and the second single-chip microcomputer and the drive module D-1 for parameter setting and data transmission; the DC power supply C-3 is connected to the drive modules in the first single-chip microcomputer and the drive module C-2 and the second single-chip microcomputer and the drive module D-1 respectively to supply power to the first programmable flow pump A-1 and the second programmable flow pump B-1; the height of the liquid storage bottle A-4 on the lifting platform A-5 is adjusted to simulate the basic pressure of the inferior vena cava; the drive module in the first single-chip microcomputer and the drive module C-2 is connected to the first programmable flow pump A-1 through a communication wire , drive the first programmable flow pump A-1 to output a waveform simulating the blood flow of the inferior vena cava, the inlet of the first programmable flow pump A-1 is connected to the outlet of the liquid storage bottle A-4 through a catheter, and the outlet of the first programmable flow pump A-1 is connected to the first inlet of the Y-type three-way pipe A-2 through a catheter; the first flow sensor C-4 is arranged at the outlet of the first programmable flow pump A-1, and is connected to the first single-chip microcomputer and the single-chip microcomputer in the driving module C-2 through a communication wire; one end of the inferior vena cava simulation tube A-3 is connected to the outlet of the Y-type three-way pipe A-2, and the other end is introduced into the liquid storage bottle A-4 fixed on the lifting platform A-5 through a catheter.

[0026] The second single-chip microcomputer is connected to the driving module in the driving module D-1 through a communication wire and the second programmable flow pump B-1 is driven to output the waveform of venous drainage; one end of the venous drainage tube B-2 enters from the second inlet of the Y-type three-way tube A-2, extends to a certain depth (the depth is adjustable) of the inferior vena cava simulation tube A-3, and the other end is connected to the inlet of the second programmable flow pump B-1 through a catheter; the second flow sensor D-2 is arranged at the drainage outlet of the venous drainage tube B-2, and is connected to the single-chip microcomputer in the second single-chip microcomputer and the driving module D-1 through a communication wire; the outlet of the second programmable flow pump B-1 is introduced into the liquid storage bottle A-4 fixed on the lifting platform A-5 through a catheter; the wireless pressure sensor D-3 and the wireless flow sensor D-4 are arranged in the part where the venous drainage tube B-2 extends to the inferior vena cava simulation tube A-3, which are used to monitor the real-time drainage flow rate and tube wall pressure of the drainage tube.

[0027] After the device is built, test experiments can be carried out. According to different situations, the inferior vena cava simulation tube A-3 can be replaced with a rigid tube and an elastic hose with the elastic characteristics of in vivo veins. The rigid tube is used to carry out drainage experiments of venous drainage tubes under different pressure conditions to test the influence of the structure and drainage method of venous drainage tubes on drainage efficiency; the elastic hose with the elastic characteristics of in vivo veins is used to carry out drainage experiments of venous drainage tubes under different pressure conditions to test the influence of the structure and drainage method of venous drainage tubes on drainage efficiency and anti-adhesion function.

[0028] The steps to complete the ex vivo drainage test of the venous drainage tube are as follows:

[0029] Step 1: Pretreatment: Install the inferior vena cava simulation tube A-3 as a rigid tube.

[0030] Step 2: Turn on the DC power supply C-3, and set the required inferior vena cava simulation waveform parameters and the drainage waveform parameters of the venous drainage tube B-2 on the main control host computer C-1.

[0031] Step 3. Press the machine switch to start the experiment. By observing the drainage flow rate and pressure value of the venous drainage tube B-2 part displayed by the main control host computer C-1 and transmitted by the wireless pressure sensor D-3 and the wireless flow sensor D-4, change the venous drainage flow rate, and record the flow rate discharged by the venous drainage tube per unit time under the corresponding conditions, and calculate the drainage efficiency.

[0032] Step 4: Turn off the machine and the rigid tube experiment is completed.

[0033] Step 5: Pretreatment: Replace the inferior vena cava simulation tube A-3 with an elastic tube having characteristic parameters of the human inferior vena cava.

[0034] Step 6: Turn on the DC power supply C-3, and set the required inferior vena cava simulation waveform parameters and the drainage waveform parameters of the venous drainage tube B-2 on the main control host computer C-1.

[0035] Step 7. By observing the drainage flow rate and pressure value of the venous drainage tube B-2 part transmitted by the wireless pressure sensor D-3 and the wireless flow sensor D-4 displayed by the main control host computer C-1, change the venous drainage flow rate, observe whether the wall adhesion phenomenon occurs, and record the flow rate discharged by the venous drainage tube per unit time under the corresponding conditions, calculate the drainage efficiency, and evaluate the anti-wall adhesion ability of the venous drainage tube.

[0036] Step 8. When the experiment is over, turn off the machine.

[0037] This circulation test system has functions such as adjusting the pump speed and monitoring hemodynamic parameters. It can simulate the blood flow environment in different clinical situations, set up different degrees of channel blockage models, and simulate the effects of thrombus. By using this circulation system, we can systematically study the influence of the drainage method of the venous drainage tube on the drainage efficiency and anti-adhesion function, and evaluate the influence of blockage on the flow state. On this basis, we can optimize the structural parameters of the venous drainage tube and appropriately adjust the position of the cannula to simulate the influence of different cannula positions on the blood flow state, optimize the design of the venous drainage tube and the drainage method to improve clinical application.

Claims

1. A double-loop circulation system for in vitro drainage testing of extracorporeal membrane oxygenation venous drainage tubes, characterized in that: Includes blood circulation simulation module and venous drainage circulation module; The blood circulation simulation module includes: a blood circulation circuit L B and blood flow control loading and signal detection unit; the blood circulation circuit L B The invention comprises: a first programmable flow pump (A-1), a Y-shaped three-way pipe (A-2), an inferior vena cava simulation tube (A-3), a liquid storage bottle (A-4) and a lifting platform (A-5); the first programmable flow pump (A-1) drives the solution in the liquid storage bottle (A-4) fixed on the lifting platform (A-5) through flow waveform programming control, and pumps the solution into the first inlet of the Y-shaped three-way pipe (A-2) through a catheter, flows through the inferior vena cava simulation tube (A-3), and finally flows back to the liquid storage bottle (A-4); the inferior vena cava simulation tube (A-3) is arranged according to the size of the inferior vena cava of the human body, The morphology and test conditions require the selection of catheters of different materials and different rigidities; the liquid storage bottle (A-4) is fixed on the lifting platform (A-5), which is higher than the common horizontal plane where the first programmable flow pump (A-1), the Y-shaped three-way pipe (A-2), and the inferior vena cava simulation tube (A-3) are located; the lifting platform (A-5) can adjust the vertical height h of the liquid storage bottle (A-4), and use Pascal's law p=ρgh to provide a basic pressure value p by adjusting the height h to simulate the basic pressure of the inferior vena cava, where ρ represents the density of the solution and g represents the acceleration of gravity; The blood flow control loading and signal detection unit comprises: a main control host computer (C-1), a first single-chip microcomputer and a driving module (C-2), a direct current power supply (C-3), and a first flow sensor (C-4); the first single-chip microcomputer and the driving module (C-2) are composed of a single-chip microcomputer and a motor driving module, the main control host computer (C-1) inputs instructions into the single-chip microcomputer in the first single-chip microcomputer and the driving module (C-2) through a communication wire, the first flow sensor (C-4) is arranged at the outlet pipe of the first programmable flow pump (A-1), and converts the flow information into flow velocity information through the formula: flow velocity V = flow rate Q / pipe diameter cross-sectional area S, and then transmits it back to the main control host computer (C-1) through the communication wire to the single-chip microcomputer in the first single-chip microcomputer and the driving module (C-2); the direct current power supply (C-3) provides a stable power electrical signal to the motor driving module in the first single-chip microcomputer and the driving module (C-2), and after the action of the motor driving module, it is loaded on the first programmable flow pump (A-1) to generate a stable motor torque and speed; The venous drainage circulation module includes: a venous drainage circulation loop L D , drainage control and signal detection unit; the venous drainage circulation loop L D The invention comprises: a second programmable flow pump (B-1) and a venous drainage tube (B-2); the second programmable flow pump (B-1) controls the solution in the venous drainage tube (B-2) which is arranged in the inferior vena cava simulation tube (A-3) and extends to the second inlet of the Y-shaped three-way tube (A-2) through flow waveform programming, and draws the solution from the inferior vena cava simulation tube (A-3) through a catheter and connects the solution storage bottle (A-4) fixed on the lifting platform (A-5); The drainage control and signal detection unit comprises: a second single-chip microcomputer and a driving module (D-1), a second flow sensor (D-2), a wireless pressure sensor (D-3), and a wireless flow sensor (D-4); the second single-chip microcomputer and the driving module (D-1) are composed of a single-chip microcomputer and a motor driving module, the main control host computer (C-1) inputs the instruction into the single-chip microcomputer in the second single-chip microcomputer and the driving module (D-1) through the communication wire, the second flow sensor (D-2) is arranged at the outlet of the venous drainage tube (B-2), and the flow information is converted into flow velocity information through the formula: flow velocity V = flow rate Q / tube diameter cross-sectional area S, and then passed through the communication wire to the second single-chip microcomputer and the driving module (D- 1) is transmitted back to the main control host computer (C-1); the wireless pressure sensor (D-3) and the wireless flow sensor (D-4) are arranged at the part of the venous drainage tube (B-2) located at the inferior vena cava simulation tube (A-3), and the drainage flow rate and pressure information at the venous drainage tube (B-2) are transmitted back to the main control host computer (C-1) in real time. The changes in the drainage flow rate and pressure information reflect the drainage efficiency and the wall adhesion. The DC power supply (C-3) provides a stable power electrical signal to the motor drive module in the second single-chip microcomputer and the drive module (D-1), and after the action of the motor drive module, it is loaded on the second programmable flow pump (B-1) to generate a stable motor torque and speed; The selection of the inferior vena cava simulation tube (A-3) is as follows: an elastic hose with the same mechanical properties as the human inferior vena cava is used to test the drainage efficiency and wall adhesion during the drainage process; a transparent rigid tube is used to eliminate the influence of wall adhesion during the drainage process and to test the drainage efficiency alone.

2. A double-loop circulation system for extracorporeal membrane oxygenation venous drainage tube ex vivo drainage testing according to claim 1, characterized in that: The blood flow control loading and signal detection unit adopts a proportional-integral-differential control method. The first flow sensor (C-4) transmits the flow rate information back to the first single-chip microcomputer and the single-chip microcomputer in the driving module (C-2). The single-chip microcomputer continuously fits the measured flow rate information with the input human inferior vena cava simulation waveform, outputs a continuously corrected pulse width modulation signal, and loads it to the first programmable flow pump (A-1) through the driving module to accurately output the set flow rate waveform.

3. A double-loop circulation system for extracorporeal membrane oxygenation venous drainage tube ex vivo drainage testing according to claim 1, characterized in that: The venous drainage tube (B-2) adopts venous drainage tubes with different clinical structural parameters such as the number of side holes, the number of side holes, the spatial distribution of side holes, etc., to test the drainage efficiency and wall adhesion of different venous drainage tubes.

4. A double-loop circulation system for extracorporeal membrane oxygenation venous drainage tube ex vivo drainage testing according to claim 1, characterized in that: The drainage control and signal detection unit adopts a proportional-integral-differential control method. The second flow sensor (D-2) transmits the flow rate information back to the second single-chip microcomputer and the single-chip microcomputer in the driving module (D-1). The single-chip microcomputer continuously fits the measured flow rate information with the input venous drainage waveform, outputs a continuously corrected pulse width modulation signal, and is loaded onto the second programmable flow pump (B-1) through the driving module to accurately output the set flow rate waveform.

5. A double-loop circulation system for extracorporeal membrane oxygenation venous drainage tube ex vivo drainage testing according to claim 1, characterized in that: The double-loop circulation system was used to explore the effects of the structure and method of venous drainage tube on drainage efficiency and venous wall adhesion. The experimental steps are as follows: Step 1: The inferior vena cava simulation tube (A-3) uses a rigid tube to carry out drainage experiments of venous drainage tubes under different pressure conditions to test the influence of venous drainage tube structure and drainage method on drainage efficiency; Step 2: Use a venous simulation tube with the elastic characteristics of in vivo veins to carry out drainage experiments of venous drainage tubes under different pressure conditions to test the effects of venous drainage tube structure and drainage method on drainage efficiency and anti-adhesion function.

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