An intravascular thrombus aspiration catheter performance evaluation system and method

Abstract

The present application belongs to the technical field of medical device simulation testing, and particularly relates to a system and method for evaluating the performance of an intravascular thrombus aspiration catheter. The present application precisely simulates the coupling effects of different atmospheric base pressures on the compliance of a flexible artificial blood vessel wall and the characteristics of a negative pressure aspiration device. It can accurately calibrate the failure threshold and performance decay law of a thrombus aspiration medical device under extreme altitude working conditions, providing real and safe surgical window data with guiding value for clinical use. At the same time, the present application solidifies the complex cross-altitude multi-parameter coupling test into a standard evaluation procedure, which can provide solid methodological support for the development of industry standardization technical standards, and can serve as a standardized testing and verification platform to assist medical device enterprises in carrying out product limit performance testing, quantitative compliance screening and high-precision algorithm calibration, thereby filling the industry gap in cross-altitude performance evaluation and engineering verification of such medical devices.

Description

Technical Field

[0001] This invention belongs to the field of medical device simulation testing technology, specifically relating to a system and method for evaluating the performance of an intravascular thrombus aspiration catheter. Background Technology

[0002] Intravascular thrombus aspiration catheters are key medical devices used in interventional procedures to remove thrombi from blood vessels and restore blood flow. Their core working principle relies on the physical pressure difference (ΔP) between an external negative pressure source and the target vascular environment, using powerful instantaneous suction to pull the thrombus attached to the vessel wall into the lumen.

[0003] However, in evaluating the performance of this device and its actual clinical application, the following physical and environmental challenges urgently need to be addressed: (1) Performance drift caused by ambient base pressure: The low air pressure in high-altitude environments leads to a severe decline in aspiration efficiency, and the rigid tube test cannot reproduce the inward collapse of flexible artificial blood vessels. These are well-known physical facts in the industry. The performance of intravascular thrombus aspiration catheters is highly dependent on the atmospheric base pressure of the working environment. In high-altitude areas such as Lhasa, the atmospheric pressure is usually below 70 kPa (far lower than 101.3 kPa in plain areas). Due to the significant drop in external ambient base pressure, the effective negative pressure physical bandwidth that the system can provide is compressed. This change in environmental pressure will cause the actual aspiration force of the device in high-altitude environments to be significantly weaker than that in plain areas. If its performance is evaluated only in plain environments, it will not be able to truly reflect its failure risk under extreme altitude conditions.

[0004] (2) The impact of diverse vascular interactions on aspiration efficiency: When evaluating the performance of intravascular thrombus aspiration catheters, using rigid tubes made of stainless steel or resin as a simulation environment cannot accurately reflect the real working condition of thrombus adhesion to the compliant vessel wall. In actual clinical aspiration, the high negative pressure generated by the catheter induces inward radial deformation of the vessel wall (collapse effect), which directly alters the hydrodynamic characteristics within the lumen. Since different types of artificial blood vessels are used in clinical practice, their material elastic modulus and compliance vary, making the interaction between the catheter and different vessel walls extremely complex and directly affecting the comprehensiveness of catheter performance evaluation.

[0005] (3) Data distortion in the evaluation system: Existing testing equipment is difficult to coordinately simulate "dynamic pulsating pressure" and "cross-altitude atmospheric base pressure" within the same system. In particular, under different absolute pressure environments, the compliance performance of different types of artificial blood vessels will drift, which will further interfere with the accurate assessment of the performance of intravascular thrombus aspiration catheters. If diverse flexible artificial blood vessel models cannot be introduced into the experimental design and the real atmospheric pressure gap cannot be simulated, the actual working critical point of the device under extreme environments will not be obtained, resulting in a serious disconnect between performance evaluation data and actual clinical performance.

[0006] Therefore, developing a comprehensive evaluation system that can accurately simulate the low-pressure environment of high altitudes and can be coupled with different types of artificial blood vessels for in-depth exploration is a physical prerequisite for objectively measuring the performance of intravascular thrombus aspiration catheters. Summary of the Invention

[0007] The purpose of this invention is to provide a performance evaluation system and testing method for intravascular thrombus aspiration catheters to solve the problems mentioned in the background art.

[0008] The technical problem to be solved by the present invention is achieved by the following technical solution: a performance evaluation system for intravascular thrombus aspiration catheter, comprising a high-simulation pressure source module, an environmental pressure simulation chamber, a coupling test module, a puncture sheath, a thrombus aspiration catheter and a negative pressure aspiration device; The environmental pressure simulation chamber is a closed test space with a first connecting pipe and a second connecting pipe on the side wall that are connected to the outside. The high-simulation pressure source module includes a constant temperature storage tank, a circulation pipeline, a first pressure regulating valve, a circulation pump, and a first pressure pump. The constant temperature storage tank contains test liquid. The constant temperature storage tank is connected to a first connecting pipeline and a second connecting pipeline through the circulation pipeline. A circulation pump is installed on the circulation pipeline. The first pressure pump is connected to the constant temperature storage tank. A first pressure regulating valve is installed between the first pressure pump and the constant temperature storage tank. The environmental pressure simulation chamber and the constant temperature storage tank are each equipped with an independent temperature control system; the temperature control system of the constant temperature storage tank is used to simulate different human body temperatures, and the temperature control system of the environmental pressure simulation chamber is used to simulate environmental temperatures. The environmental pressure simulation chamber is connected to a vacuum pump and a second pressurizing pump, and a second pressure regulating valve is provided between the second pressurizing pump and the environmental pressure simulation chamber. The coupling test module includes a first adapter and a second adapter installed in an environmental pressure simulation chamber. The first adapter and the second adapter are detachably connected to a first connecting pipe and a second connecting pipe, respectively. The first adapter and the second adapter are used to connect an artificial blood vessel. The artificial blood vessel is detachably installed on the first adapter and the second adapter. The inner wall of the artificial blood vessel is provided with simulated thrombi. The artificial blood vessel is connected to the first adapter and the second adapter via slip rings. The outer sides of the ends of the first adapter and the second adapter are respectively provided with a first conical surface, and the inner side of the slip ring is provided with a second conical surface that matches the first conical surface. The artificial blood vessel is disposed between the first conical surface and the second conical surface. The first adapter, the second adapter, the first connecting pipe, the second connecting pipe, and the circulation pipe are all made of rigid materials; The puncture sheath is connected to an artificial blood vessel, and the inlet of the puncture sheath is located outside the environmental pressure simulation chamber; The thrombus aspiration catheter is inserted into the artificial blood vessel through the puncture sheath. The thrombus aspiration catheter is connected to the negative pressure aspiration device, which is located outside the environmental pressure simulation chamber. A flow meter is installed on the thrombus aspiration catheter. Isolation valves are respectively installed on the first and second adapters. This invention utilizes a slip ring connection to solve the industry problem of conventional mechanical clamping easily crushing and damaging flexible artificial blood vessels, ensuring absolute physical isolation between the internal flow channel of the artificial blood vessel and the air pressure inside the chamber when the environmental pressure simulation chamber is evacuated to below 70 kPa. Furthermore, it facilitates the disassembly and installation of the artificial blood vessel.

[0009] Preferably, the simulated thrombus is formed into the desired shape on the inner wall of the artificial blood vessel by casting or cutting using a mold.

[0010] Preferably, the temperature control system of this invention includes an electric heating device and a temperature sensor installed in the environmental pressure simulation chamber and the constant temperature storage tank. The control system enables closed-loop control of the temperature of the medium inside the environmental pressure simulation chamber and the constant temperature storage tank.

[0011] Preferably, the first connecting pipe and the second connecting pipe are connected to the bottom of the constant temperature storage tank to avoid the influence of gas on the test results.

[0012] Preferably, the circulation pipeline is provided with a section of silicone tube for connecting the puncture sheath, which facilitates the insertion of the thrombus aspiration catheter from the outside of the environmental pressure simulation chamber without affecting the installation and removal of the artificial blood vessel.

[0013] This invention also discloses a method for evaluating the performance of an intravascular thrombus aspiration catheter, utilizing the aforementioned intravascular thrombus aspiration catheter performance evaluation system, comprising the following steps: S1, Catheter intervention and thrombus implantation A simulated thrombus is implanted at a predetermined location on the artificial blood vessel, and the puncture sheath is guided from the outside of the environmental pressure simulation chamber to the entrance of the artificial blood vessel. The thrombus aspiration catheter is inserted into the artificial blood vessel through the puncture sheath, and the tip of the thrombus aspiration catheter is brought into contact with the simulated thrombus. Connect the thrombus aspiration catheter to the negative pressure aspiration device; S2, Physiological Blood Pressure Simulation The artificial blood vessel to be tested is connected between the first and second adapters, and the test liquid is injected into the constant temperature storage tank. The temperature control system is used to control the test liquid in the constant temperature storage tank to stabilize at the preset temperature, simulating the human body temperature. Start the circulation pump to circulate the test liquid between the thermostatic storage tank and the artificial blood vessel; Under different altitude conditions, the pressure inside the constant temperature storage tank is adjusted by the first pressurizing pump and the first pressure regulating valve, and simulated human pulsating blood pressure is applied to the artificial blood vessel based on the atmospheric pressure at the corresponding altitude. The fluctuation of human blood pressure under different altitude pressures is "the local altitude pressure plus the pulsating blood pressure in the human body". For example, the venous pressure and arterial pressure of a person are 75~120 mmHg. In Jinan, it is 101 kPa + 75~120 mmHg; in Lhasa, it is 66 kPa + 75~120 mmHg. S3, Base Pressure Simulation The pressure inside the environmental pressure simulation chamber is adjusted by using a vacuum pump, a second pressurizing pump, and a second pressure regulating valve to simulate atmospheric pressure under corresponding altitude conditions. For example, the environmental pressure simulation chamber can be evacuated by the vacuum pump to reach the preset simulation pressure to simulate non-standard atmospheric pressure under corresponding altitude conditions. This method can be used to simulate any atmospheric base pressure environment below 70 kPa. The temperature control system is used to stabilize the gas in the environmental pressure simulation chamber at a preset temperature, simulating the environmental temperature under corresponding altitude conditions. S4. Dynamic Evaluation of Suction Performance Start the negative pressure suction device to perform the suction task. Set the pressure of the negative pressure suction device at the corresponding altitude according to the preset simulated pressure in the environmental pressure simulation chamber. Record the time T for thrombus aspiration to be completed or the proportion of thrombus residue within a preset time at different altitudes; Residual percentage = (residual thrombus weight / initial thrombus weight) × 100%; Record the aspiration flow rate of the thrombus aspiration catheter at different altitudes; the aspiration flow rate is a clinical use parameter of the aspiration catheter, and it was controlled according to the flow rate requirements during the experiment; The simulated altitude is used as the horizontal axis and the corresponding suction completion time T is used as the vertical axis to perform data fitting and generate a feature curve. The simulated altitudes and the corresponding residual proportion of thrombi within a preset time are fitted to generate characteristic curves.

[0014] Under the same high-altitude, low-pressure conditions, catheter A removed the blood clot in 10 seconds, while catheter B took 30 seconds. Clearly, catheter A performed better clinically and saved lives faster in extreme environments.

[0015] Residual percentage: This refers to how cleanly the blood was aspirated. After aspiration stops, some fragmented thrombi may remain on the vessel wall. Residual percentage = (weight of residual thrombi / weight of initial thrombi) × 100%. The lower this number, the stronger the catheter performance and the better the clinical recanalization effect.

[0016] Preferably, the present invention further includes step S5, adjusting the hardness, viscosity or shape of the simulated thrombus on the inner wall of the artificial blood vessel, and repeating steps S1-S4.

[0017] The preferred method of this invention for determining the residual proportion of thrombus within a preset time is as follows: The mass of the simulated thrombus implanted in step S1 is M1; The simulated thrombus with mass M1 was dried to obtain the dried simulated thrombus with mass M2. In step S4, the simulated thrombus drawn out by the negative pressure suction device (400) is dried, and the mass of the dried simulated thrombus is M3. The residual percentage of the simulated thrombus in the artificial blood vessel (500) is ((M2-M3) / M2)×100%.

[0018] This invention aims to provide a simulation system capable of accurately evaluating the performance of intravascular thrombus aspiration catheters. It simulates the impact of different atmospheric base pressures (such as environments below 70 kPa in Lhasa) on vascular wall compliance and negative pressure aspiration devices, thereby reflecting the failure threshold of thrombus aspiration medical devices under extreme altitude conditions. For example, in Jinan, due to the high atmospheric pressure, the negative pressure aspiration device can provide a negative pressure value of -85 kPa. However, in Lhasa, where the atmospheric pressure is only -66 kPa, the same negative pressure source will only provide a negative pressure value of -50 kPa, rendering the device ineffective for aspiration during surgery.

[0019] The entire experiment of this invention is based on the controlled variable method (keeping the same artificial blood vessel, the same simulated thrombus, and the same pulsatile blood pressure conditions), and comprehensively evaluates the working effect of medical devices at specific high altitudes by changing the vacuum degree in the environmental pressure simulation chamber (simulating atmospheric pressure at different altitudes).

[0020] (i) The ability to complete the suction within the specified time is used to evaluate "suction efficiency / time performance". Experimental procedure: Under specific simulated altitude and air pressure, if the catheter can completely aspirate the thrombus within the clinically prescribed time, the aspiration completion time T is directly recorded.

[0021] The output chart is: Altitude-Aspiration Time Curve.

[0022] Clinical assessment value: A curve is presented showing that the aspiration time (T) increases with altitude (decreased air pressure). This serves as guidance for physicians: How much will the efficiency of the instruments decrease with increasing altitude in the patient's location? Is the procedure being performed within the safe surgical window?

[0023] (ii) Samples not collected within the specified time will be used to assess "residual performance". Experimental procedure: Set a fixed clinical surgery cutoff time. If the thrombus cannot be completely removed within the time limit (indicating that the instrument's effectiveness is limited at this altitude), then weigh the total weight difference of "artificial blood vessel + thrombus" before and after the experiment using a high-precision balance (total weight before the experiment M1 minus the residual total weight after the experiment M2), and obtain the absolute mass of the successfully removed thrombus ΔM = M1 - M2.

[0024] Output chart: Altitude-Suction Effect / Residual Mass Curve.

[0025] Clinical evaluation value: A trend curve is presented showing a decrease in thrombus clearance rate and an increase in residual thrombus mass with increasing altitude and within a fixed surgical time. This serves as guidance for physicians: What is the ultimate clearance effect of this instrument within the prescribed surgical time? How much thrombus will ultimately remain? Compared with the prior art, the beneficial effects of the present invention are: This invention, by accurately simulating the coupled effects of different atmospheric base pressures on the compliance of flexible artificial blood vessel walls and the characteristics of negative pressure aspiration devices, can not only precisely calibrate the failure threshold and performance decay patterns of thrombus aspiration medical devices under extreme altitude conditions, providing clinically valuable real-world safety surgical window data; but also solidify complex cross-altitude multi-parameter coupling tests into a standard evaluation procedure, providing solid methodological support for the development of standardized technical standards in the industry. Furthermore, it can serve as a standardized testing and verification platform, assisting medical device companies in conducting extreme performance testing, quantitative compliance screening, and high-precision algorithm calibration, filling the industry gap in cross-altitude performance evaluation and engineering verification of such medical devices. Attached Figure Description

[0026] Figure 1 A schematic diagram of the performance evaluation system for intravascular thrombus aspiration catheters; Figure 2 A three-dimensional view of an intravascular thrombus aspiration catheter performance evaluation system; The diagram shows: 100 environmental pressure simulation chamber, 200 puncture sheath, 300 thrombus aspiration catheter, and 400 negative pressure aspiration device. 101 First connecting pipe, 102 Second connecting pipe; 1. Constant temperature storage tank; 2. Circulation pipeline; 3. First pressure regulating valve; 4. Circulation pump; 5. First pressurizing pump; 6. Vacuum pump; 7. Second pressurizing pump; 8. Second pressure regulating valve; 9. First adapter; 10. Second adapter. 500 artificial blood vessels, 600 slip rings, 700 flow meters, 11 isolation valves, 21 silicone tubing, 12 electric heating devices, and 13 temperature sensors. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0028] like Figure 1 and Figure 2 As shown, an intravascular thrombus aspiration catheter performance evaluation system includes a high-fidelity pressure source module, an environmental pressure simulation chamber 100, a coupling test module, a puncture sheath 200, a thrombus aspiration catheter 300, and a negative pressure aspiration device 400.

[0029] The environmental pressure simulation chamber 100 is a closed test space, and a first connecting pipe 101 and a second connecting pipe 102 connected to the outside are provided on the side wall.

[0030] The high-simulation pressure source module includes a constant-temperature storage tank 1, a circulation pipeline 2, a first pressure regulating valve 3, a circulation pump 4, and a first pressurizing pump 5. The constant-temperature storage tank 1 contains a test liquid, which may be water or simulated blood. The constant-temperature storage tank 1 is connected to a first connecting pipeline 101 and a second connecting pipeline 102 via the circulation pipeline 2. The circulation pump 4 is installed on the circulation pipeline 2. The first pressurizing pump 5 is connected to the constant-temperature storage tank 1, and the first pressure regulating valve 3 is installed between the first pressurizing pump 5 and the constant-temperature storage tank 1. In this embodiment, the first connecting pipeline 101 and the second connecting pipeline 102 are respectively connected to the bottom of the constant-temperature storage tank 1.

[0031] The environmental pressure simulation chamber 100 and the constant temperature storage tank 1 are each equipped with an independent temperature control system.

[0032] Specifically, the temperature control system includes an electric heating device 12 and a temperature sensor 13 installed in the environmental pressure simulation chamber 100 and the constant temperature storage tank 1.

[0033] The environmental pressure simulation chamber 100 is connected to the vacuum pump 6 and the second pressurizing pump 7 respectively, and a second pressure regulating valve 8 is provided between the second pressurizing pump 7 and the environmental pressure simulation chamber 100.

[0034] The coupling test module includes a first adapter 9 and a second adapter 10 disposed within an environmental pressure simulation chamber 100. The first adapter 9 and the second adapter 10 are detachably connected to the first connecting pipe 101 and the second connecting pipe 102 respectively (with interference fit or threaded connection). The first adapter 9 and the second adapter 10 are used to connect an artificial blood vessel 500. The artificial blood vessel 500 is detachably disposed on the first adapter 9 and the second adapter 10. The inner wall of the artificial blood vessel 500 is provided with simulated thrombi.

[0035] The artificial blood vessel 500 is connected to the first adapter 9 and the second adapter 10 via slip rings 600. The outer ends of the first adapter 9 and the second adapter 10 are respectively provided with a first conical surface, and the inner side of the slip ring 600 is provided with a second conical surface that matches the first conical surface. The artificial blood vessel 500 is disposed between the first and second conical surfaces. The slip ring 600 is either interference-fitted with the first adapter 9 and the second adapter 10 or connected via threads.

[0036] The first adapter 9, the second adapter 10, the first connecting pipe 101, the second connecting pipe 102, and the circulation pipe 2 are all made of rigid materials to avoid affecting the compliance of the artificial blood vessel and to ensure the accuracy of the test results. For example, the first connecting pipe 101 and the second connecting pipe 102 are polytetrafluoroethylene (PTFE) pipes.

[0037] The puncture sheath 200 is connected to the artificial blood vessel 500, and the inlet of the puncture sheath 200 is located outside the environmental pressure simulation chamber 100. Specifically, a silicone tube 21 is provided on the circulation pipe 2 for connecting the puncture sheath 200.

[0038] The thrombus aspiration catheter 300 is inserted into the artificial blood vessel 500 through the puncture sheath 200. The thrombus aspiration catheter 300 is connected to a negative pressure aspiration device 400, which is located outside the environmental pressure simulation chamber 100. A flow meter 700 is installed on the thrombus aspiration catheter 300. A flow meter is connected in series in the peripheral tubing of the artificial blood vessel 500. The flow meter is electrically connected to the control software and is used to collect and transmit dynamic aspiration flow data to the control software in real time.

[0039] Isolation valves 11 are respectively provided on the first adapter 9 and the second adapter 10.

[0040] The simulated thrombus is formed into the desired shape on the inner wall of the artificial blood vessel 500 by casting or cutting using a mold. The inner wall of the artificial blood vessel 500 is provided with simulated thrombi of different hardness, viscosity and shape.

[0041] A method for evaluating the performance of an intravascular thrombus aspiration catheter, utilizing the intravascular thrombus aspiration catheter performance evaluation system described in this embodiment, includes the following steps: S1, Catheter intervention and thrombus implantation A simulated thrombus is implanted at a predetermined location in the artificial blood vessel 500, and the puncture sheath 200 is guided from the outside of the environmental pressure simulation chamber 100 to the entrance of the artificial blood vessel.

[0042] The thrombus aspiration catheter 300 is inserted into the artificial blood vessel through the puncture sheath 200, and the tip of the thrombus aspiration catheter 300 is brought into contact with the simulated thrombus.

[0043] Connect the thrombus aspiration catheter 300 to the negative pressure aspiration device 400.

[0044] S2, Physiological Blood Pressure Simulation The artificial blood vessel 500 to be tested is connected between the first adapter 9 and the second adapter 10. Test liquid is injected into the constant temperature storage tank 1. The temperature control system is used to control the test liquid in the constant temperature storage tank 1 to stabilize at the preset temperature, simulating human body temperature.

[0045] Start the circulation pump 4 to circulate the test liquid between the constant temperature storage tank 1 and the artificial blood vessel 500.

[0046] Under different altitude conditions, the pressure inside the constant temperature storage tank 1 is adjusted by the first pressurizing pump 5 and the first pressure regulating valve 3, and simulated human pulsating blood pressure is applied to the artificial blood vessel 500 based on the atmospheric pressure at the corresponding altitude.

[0047] S3, Base Pressure Simulation The pressure inside the environmental pressure simulation chamber 100 is adjusted by using vacuum pump 6, second pressurization pump 7, and second pressure regulating valve 8 to simulate atmospheric pressure under corresponding altitude conditions.

[0048] The temperature control system is used to stabilize the gas in the environmental pressure simulation chamber 100 at a preset temperature, simulating the environmental temperature under corresponding altitude conditions.

[0049] S4. Dynamic Evaluation of Suction Performance The negative pressure suction device 400 is activated to perform the suction task. The pressure of the negative pressure suction device 400 at the corresponding altitude is set according to the preset simulated pressure in the environmental pressure simulation chamber 100.

[0050] Record the time T for complete thrombus aspiration or the percentage of thrombus residue within a preset time at different altitudes. Record the time for complete thrombus aspiration and the percentage of thrombus residue within a preset time under the current altitude environment and corresponding vascular compliance conditions.

[0051] Residual percentage = (residual thrombus weight / initial thrombus weight) × 100%; Specifically, the method for determining the percentage of residual thrombus within a preset time is as follows: The mass of the simulated thrombus implanted in step S1 is M1.

[0052] A simulated thrombus with mass M1 was dried to obtain a dried simulated thrombus with mass M2.

[0053] In step S4, the simulated thrombus aspirated by the negative pressure suction device 400 is dried, and the mass of the dried simulated thrombus is M3.

[0054] The residual proportion of the simulated thrombus within the artificial blood vessel 500 is ((M2-M3) / M2)×100%. By fixing the initial mass of the simulated thrombus implanted in the artificial blood vessel, the simulated thrombus is dried using uniform drying process conditions to obtain its mass after drying. The aspirated simulated thrombus is dried using the same method, and then used to determine the proportion of simulated thrombus remaining inside the artificial blood vessel. By removing all moisture from the simulated thrombus, the influence of different water contents and absorption rates of the simulated thrombus can be effectively eliminated, ensuring the accuracy of the measurement data. Existing drying ovens can be used for drying; the drying temperature and time can be set as needed.

[0055] Record the aspiration flow rate of the thrombus aspiration catheter 300 at different altitudes. Record the deformation of the artificial blood vessel wall (collapse effect) under aspiration negative pressure and its dynamic interference with the catheter aspiration flow rate.

[0056] By using each simulated altitude as the x-axis and the corresponding suction completion time T as the y-axis, data fitting is performed to generate a characteristic curve.

[0057] The simulated altitudes and the corresponding residual proportion of thrombi within a preset time are fitted to generate characteristic curves.

[0058] The method for evaluating the performance of the intravascular thrombus aspiration catheter further includes step S5, adjusting the hardness, viscosity, or shape of the simulated thrombus on the inner wall of the artificial blood vessel 500, and repeating steps S1-S4. Specifically, the elasticity, viscosity, and shape of the simulated thrombus can be adjusted according to the needs of the simulation experiment. For example, the elasticity of the simulated thrombus can be changed by adjusting the ratio of guar gum to borax, where borax dominates the formation of the cross-linked network, transforming the material from a viscous fluid into an elastic gel; while when only guar gum (without borax) is used, it mainly provides viscosity and has virtually no elasticity.

[0059] Alternatively, the elasticity of the simulated thrombus can be altered by adjusting the ratio of polyacrylamide (PAAM) to alginate—high acrylamide concentration (e.g., 90% PAAM-Alg) corresponds to a hard thrombus, while high alginate concentration (e.g., 83% PAAM-Alg) corresponds to a soft thrombus. The two form an interpenetrating network, allowing for decoupled control of elasticity and viscosity, transforming the material from a simple viscous fluid into a gel with adjustable elasticity.

[0060] The composition and preparation method of the simulated thrombus are existing technologies and can be found in relevant literature, so they will not be described in detail here.

[0061] The shape of a simulated thrombus can be achieved through mold casting or cutting.

[0062] By combining quantitative data on the compliance of artificial blood vessels at different altitudes, this study evaluates the failure threshold and performance degradation pattern of thrombus aspiration catheters within artificial blood vessels in practical applications. Simulated thrombi are aspirated from the artificial blood vessel, and the amount of thrombi aspirated within a specified time is assessed using a weighing method to evaluate the failure threshold and performance degradation pattern of the thrombus aspiration medical device.

[0063] The so-called failure refers to the medical device's inability to complete the thrombus aspiration surgery within the specified time under specific high-altitude and low-pressure conditions.

[0064] After the test is completed, slowly restore the test chamber to normal pressure and shut down the heating and pumping systems.

[0065] Clean up any remaining tubing, replace with different types of artificial blood vessels as needed for the experiment, and proceed to the next round of coupling tests.

[0066] The performance evaluation system and method for intravascular thrombus aspiration catheters described in this invention do not use pressure or flow rate as the core evaluation index. Instead, it constructs a unified flexible blood vessel and thrombus-loaded environment, and simulates atmospheric pressure gaps at different altitudes by changing the vacuum level of the environmental pressure simulation chamber 100. Finally, it outputs two comprehensive characteristic curves that intuitively reflect the clinical working effect and efficacy evolution of the device: 1) Evaluation curve of "altitude-aspiration completion time" under specific thrombus load: To ensure thrombus aspiration can be completed within a specified time, the time T required for a thrombus aspiration catheter 300 to completely remove a simulated thrombus was recorded at different simulated altitudes and atmospheric pressures. A characteristic curve was generated by fitting the data with each simulated altitude (or absolute atmospheric pressure) as the x-axis and the corresponding aspiration completion time T as the y-axis. This curve aims to provide clinicians with a visual assessment of the decrease in instrument efficiency and changes in surgical time costs due to increased altitude. (ii) Evaluation curve of "altitude-aspiration effect / residual mass" within a limited surgical time: To address situations where thrombi cannot be completely removed within a specified time, resulting in limited effectiveness, a clinically mandated surgical cutoff time is established. Before the experiment begins, the initial total mass M1 of the simulated thrombus and the initial total mass M2 after drying are weighed using a high-precision balance. Aspiration is performed under specific simulated altitude and air pressure, and the experiment is forcibly terminated after the specified time. Subsequently, the extracted simulated thrombus is filtered, collected, and subjected to the same drying process. The mass M3 of the dried extracted simulated thrombus is then weighed using a high-precision balance to obtain the residual proportion of the simulated thrombus within the artificial blood vessel 500. The vacuum level of the simulation chamber 100 is varied to simulate different altitudes, and the above steps are repeated. Multiple sets of altitude data are fitted with the corresponding residual proportion of thrombi (or thrombus clearance rate, residual proportion) within the preset time to generate a characteristic curve. This curve aims to provide clinicians with a direct assessment of the interference of high altitude and low pressure on the instrument's effectiveness and to quantitatively evaluate the actual limit clearance effect and thrombus residue performance of the medical device within the limited surgical time.

Claims

1. A performance evaluation system for an intravascular thrombus aspiration catheter, characterized in that: Includes a high-fidelity pressure source module, an environmental pressure simulation chamber (100), a coupling test module, a puncture sheath (200), a thrombus aspiration catheter (300), and a negative pressure aspiration device (400): The environmental pressure simulation chamber (100) is a closed test space, and a first connecting pipe (101) and a second connecting pipe (102) connected to the outside are provided on the side wall. The high-simulation pressure source module includes a constant temperature storage tank (1), a circulation pipeline (2), a first pressure regulating valve (3), a circulation pump (4), and a first pressurizing pump (5). The constant temperature storage tank (1) contains test liquid. The constant temperature storage tank (1) is connected to a first connecting pipeline (101) and a second connecting pipeline (102) through the circulation pipeline (2). The circulation pipeline (2) is equipped with a circulation pump (4). The first pressurizing pump (5) is connected to the constant temperature storage tank (1). The first pressure regulating valve (3) is provided between the first pressurizing pump (5) and the constant temperature storage tank (1). The environmental pressure simulation chamber (100) and the constant temperature storage tank (1) are each equipped with an independent temperature control system; The environmental pressure simulation chamber (100) is connected to the vacuum pump (6) and the second pressurizing pump (7) respectively. A second pressure regulating valve (8) is provided between the second pressurizing pump (7) and the environmental pressure simulation chamber (100). The coupling test module includes a first adapter (9) and a second adapter (10) disposed in an environmental pressure simulation chamber (100). The first adapter (9) and the second adapter (10) are detachably connected to a first connecting pipe (101) and a second connecting pipe (102), respectively. The first adapter (9) and the second adapter (10) are used to connect an artificial blood vessel (500). The artificial blood vessel (500) is detachably disposed on the first adapter (9) and the second adapter (10). The inner wall of the artificial blood vessel (500) is provided with simulated thrombi. The artificial blood vessel (500) is connected to the first adapter (9) and the second adapter (10) respectively via a slip ring (600). The outer sides of the ends of the first adapter (9) and the second adapter (10) are respectively provided with a first conical surface. The inner side of the slip ring (600) is provided with a second conical surface that matches the first conical surface. The artificial blood vessel (500) is disposed between the first conical surface and the second conical surface. The first adapter (9), the second adapter (10), the first connecting pipe (101), the second connecting pipe (102), and the circulation pipe (2) are all made of rigid materials; The puncture sheath (200) is connected to the artificial blood vessel (500), and the inlet of the puncture sheath (200) is located outside the environmental pressure simulation chamber (100); The thrombus aspiration catheter (300) is inserted into the artificial blood vessel (500) through the puncture sheath (200). The thrombus aspiration catheter (300) is connected to the negative pressure aspiration device (400). The negative pressure aspiration device (400) is located outside the environmental pressure simulation chamber (100). A flow meter (700) is installed on the thrombus aspiration catheter (300). Isolation valves (11) are respectively provided on the first adapter (9) and the second adapter (10).

2. The performance evaluation system for intravascular thrombus aspiration catheters according to claim 1, characterized in that: The simulated thrombus is formed into the desired shape on the inner wall of the artificial blood vessel (500) by casting or cutting using a mold.

3. The performance evaluation system for intravascular thrombus aspiration catheters according to claim 1, characterized in that: The temperature control system includes an electric heating device (12) and a temperature sensor (13) installed in the environmental pressure simulation chamber (100) and the constant temperature storage tank (1).

4. The performance evaluation system for intravascular thrombus aspiration catheters according to claim 1, characterized in that: The first connecting pipe (101) and the second connecting pipe (102) are respectively connected to the bottom of the constant temperature storage tank (1).

5. The performance evaluation system for intravascular thrombus aspiration catheters according to claim 1, characterized in that: A section of silicone tube (21) is provided on the circulation pipe (2) for connecting the puncture sheath tube (200).

6. A method for evaluating the performance of an intravascular thrombus aspiration catheter, utilizing the intravascular thrombus aspiration catheter performance evaluation system according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1, Catheter intervention and thrombus implantation A simulated thrombus is implanted at a predetermined location in the artificial blood vessel (500), and the puncture sheath (200) is guided from the outside of the environmental pressure simulation chamber (100) to the entrance of the artificial blood vessel; The thrombus aspiration catheter (300) is inserted into the artificial blood vessel through the puncture sheath (200), and the tip of the thrombus aspiration catheter (300) is brought into contact with the simulated thrombus. Connect the thrombus aspiration catheter (300) to the negative pressure aspiration device (400); S2, Physiological Blood Pressure Simulation Connect the artificial blood vessel (500) to be tested between the first adapter (9) and the second adapter (10), inject the test liquid into the constant temperature storage tank (1), and use the temperature control system to control the test liquid in the constant temperature storage tank (1) to stabilize at the preset temperature, simulating the human body temperature; Start the circulation pump (4) to make the test liquid circulate between the constant temperature storage tank (1) and the artificial blood vessel (500); Under different altitude conditions, the pressure inside the constant temperature storage tank (1) is adjusted by the first pressurizing pump (5) and the first pressure regulating valve (3), and simulated human pulsating blood pressure is applied to the artificial blood vessel (500) based on the atmospheric pressure at the corresponding altitude. S3, Base Pressure Simulation The pressure inside the environmental pressure simulation chamber (100) is adjusted by using a vacuum pump (6), a second pressurizing pump (7), and a second pressure regulating valve (8) to simulate the atmospheric pressure under corresponding altitude conditions; The gas inside the environmental pressure simulation chamber (100) is kept at a preset temperature by using a temperature control system to simulate the environmental temperature under corresponding altitude conditions. S4. Dynamic Evaluation of Suction Performance Start the negative pressure suction device (400) to perform the suction task. According to the preset simulation pressure in the environmental pressure simulation chamber (100), set the pressure of the negative pressure suction device (400) at the corresponding altitude. Record the time T for thrombus aspiration to be completed or the proportion of thrombus residue within a preset time at different altitudes; Residual percentage = (residual thrombus weight / initial thrombus weight) × 100%; Record the aspiration flow rate of the thrombus aspiration catheter (300) at different altitudes; The simulated altitude is used as the horizontal axis and the corresponding suction completion time T is used as the vertical axis to perform data fitting and generate a feature curve. The simulated altitudes and the corresponding residual proportion of thrombi within a preset time are fitted to generate characteristic curves.

7. The method for evaluating the performance of an intravascular thrombus aspiration catheter according to claim 6, characterized in that: It also includes step S5, adjusting the hardness, viscosity or shape of the simulated thrombus on the inner wall of the artificial blood vessel (500), and repeating steps S1-S4.

8. The method for evaluating the performance of an intravascular thrombus aspiration catheter according to claim 6, characterized in that: The method for determining the percentage of residual thrombus within a preset time is as follows: The mass of the simulated thrombus implanted in step S1 is M1; The simulated thrombus with mass M1 was dried to obtain the dried simulated thrombus with mass M2. In step S4, the simulated thrombus drawn out by the negative pressure suction device (400) is dried, and the mass of the dried simulated thrombus is M3. The residual percentage of the simulated thrombus in the artificial blood vessel (500) is ((M2-M3) / M2)×100%.

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