System and method for testing compliance of artificial blood vessel

Abstract

The invention discloses a system and a method for testing compliance of an artificial blood vessel, and relates to the technical field of medical instrument testing equipment. The device comprises a testing bin, a sample to be tested can be contained in the testing bin, and the testing bin is provided with a liquid inlet pipe and a liquid outlet pipe which are communicated with an inner cavity of the sample to be tested; and the main circulation liquid path comprises a liquid inlet channel and a liquid outlet channel which are communicated with the test bin, and an external liquid circulation system communicated with the liquid inlet channel and the liquid outlet channel. Under the constant temperature condition of 37 DEG C, a physiological liquid flowing environment is simulated, pulse type and continuous liquid flow modes are compatible, different operation cycles and target flows can be set according to test requirements, and structural response evaluation and compliance endpoint evaluation of a sample under long-term dynamic loading are achieved; the system has the advantages of being closed in structure, stable in operation, adjustable in parameter, high in repeatability and the like, and is suitable for compliance characteristic verification and comparative study of catheter instruments.

Description

Technical Field

[0001] This invention belongs to the field of medical device testing equipment technology, and in particular relates to a system and method for testing the compliance of artificial blood vessels. Background Technology

[0002] Long-term implantable endovascular medical devices, such as artificial blood vessels, urinary stents, and gastrointestinal feeding catheters, play a crucial role in clinical applications. These devices not only need to withstand complex physiological stress environments, including continuous fluid impact, cavity peristalsis, and tissue compression, but also need to adapt to varying conditions such as internal temperature and humidity. Among these, compliance, as a core indicator measuring the structural volume response capability of a device under dynamic pressure, is directly related to the device's tissue compatibility, fluid patency, and control of long-term complications, and is a key factor in ensuring patient treatment safety and efficacy.

[0003] Taking artificial blood vessels as an example, their compliance needs to match that of natural blood vessels in order to maintain hemodynamic stability, reduce the risk of turbulence and thrombosis, and thus protect the patient's life and health. Similarly, urinary stents need to remain unobstructed under the regular contraction and expansion of the urinary system to prevent urine retention and infection. Gastrointestinal nutrition catheters, on the other hand, need to maintain the integrity of the lumen structure and the stability of function in the complex environment of the digestive tract, including peristalsis, high humidity and high temperature conditions, to ensure effective delivery of nutrients.

[0004] However, existing compliance testing methods have significant limitations. Most testing methods still rely on static pressure combined with single-point measurement, which cannot effectively simulate the continuous fluid flow state and performance changes of devices under long-term stress loads in vivo. For example, artificial blood vessel compliance testing equipment cannot stably simulate the blood environment, lacks accuracy, and has poor long-term testing stability, making it difficult to meet the high standards of reliability and quantifiability required by modern clinical and registration testing.

[0005] Against this backdrop, it is particularly urgent and indispensable to develop a compliance testing system that is modular in structure, has a settable operating cycle, can simulate different types of fluid modes (such as pulsed or continuous flow), and supports temperature control (such as 37°C) and liquid circulation. Summary of the Invention

[0006] The purpose of this invention is to provide a system and method for compliance testing of artificial blood vessels. With core advantages such as simulating the real physiological environment, dynamic loading assessment, precise endpoint quantification, structural closure and stability, wide applicability, non-destructive and high repeatability, and convenient operation, it provides an innovative solution for compliance testing of long-term implantable endovascular medical devices and has significant clinical and industrial application value.

[0007] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: In a first aspect, the present invention provides a system for testing the compliance of artificial blood vessels, comprising a test chamber that can accommodate a sample to be tested, and the test chamber is provided with an inlet pipe and an outlet pipe communicating with the inner cavity of the sample to be tested.

[0008] A main circulating fluid circuit includes an inlet channel and an outlet channel connected to the test chamber, and an external fluid circulation system connected to the inlet channel and the outlet channel. The external fluid circulation system includes a peristaltic pump and two three-way PVC hoses connected to each other to simulate the fluid circulation environment in the human body. The third ends of the two three-way PVC hoses are respectively connected to the inlet pipe and the outlet pipe.

[0009] A pressure loading tube applies a constant rated pressure to the sample cavity during the endpoint evaluation phase via a controllable pressurization device.

[0010] Multiple valves are used to control the opening and closing of the liquid channels during the testing process.

[0011] A filling structure is provided at the upper end of the test chamber for venting gas before testing.

[0012] An exhaust structure is provided, which is located at the upper end of the test chamber.

[0013] As a preferred embodiment of the present invention, the test chamber is made of polytetrafluoroethylene.

[0014] As a preferred embodiment of the present invention, each of the inlet pipe, outlet pipe, inlet channel, outlet channel and pressure loading pipe is provided with a valve.

[0015] As a preferred embodiment of the present invention, the controllable pressurization device includes a syringe, an infusion tube with a Luer female connector is installed on the syringe, and a Luer male connector is provided at the end of the pressure loading tube.

[0016] As a preferred embodiment of the present invention, the filling structure includes a filling pipe that passes through and is fixed to the top of the test chamber; a shut-off valve is installed on the filling pipe.

[0017] As a preferred embodiment of the present invention, the exhaust structure includes an overflow pipe that runs through and is fixed to the top of the test chamber.

[0018] As a preferred embodiment of the present invention, a non-contact flow meter is installed on the inlet pipe and the inlet channel respectively.

[0019] In a second aspect, this application provides a method for testing the compliance of artificial blood vessels, applied to the system for testing the compliance of artificial blood vessels described in the first aspect. The method for testing the compliance of artificial blood vessels includes an initial preparation phase, a long-term loading operation phase, and a compliance endpoint assessment phase, all completed in a constant temperature chamber. The initial preparation phase includes the following steps: S01, Injection: Inject the circulating medium from the injection tube into the test chamber; S02. Circulation and exhaust: After the liquid level in the test chamber exceeds the height of the inlet pipe and the outlet pipe, open all the valves, start the peristaltic pump in the main circulation circuit, and close the valve on the pressure loading pipe after it stably outputs the circulating medium. When the inlet pipe and the inlet channel no longer output bubbles into the test chamber, and there are no bubbles in the test chamber, close the shut-off valve and the peristaltic pump, and then close all the valves. The long-term loading and running phase includes the following steps: SS01. After completing the initial preparation stage, open the inlet pipe, outlet pipe, inlet channel and outlet channel, and turn on the peristaltic pump to drive the circulating medium to circulate in the sample to be tested and in the test chamber. SS02. Set the peristaltic pump operating mode. The peristaltic pump can switch between pulse or continuous operating modes to adapt to the clinical use environment of different devices. SS03. Flow monitoring: The flow rate is monitored in real time by non-contact flow meters installed on the inlet pipe and the inlet channel respectively, and targeted load simulation is achieved by adjusting the valves on the inlet pipe and the inlet channel respectively. SS04. Set the operating cycle and set the long-term operating time for the peristaltic pump; The compliance endpoint assessment phase includes the following steps: SSS01. After completing the long-term loading and running phase, install the overflow module, insert the U-shaped overflow conduit into the overflow pipe, and place the waste liquid collection tank directly below the output end of the U-shaped overflow conduit. SSS02: Close the valves on the inlet pipe, outlet pipe, inlet channel, and outlet channel; connect the controllable pressurization device to the upper end of the pressure loading pipe; and push at constant pressure. SSS03, Measure the liquid overflow length, measure and calculate the volume V1 of the liquid column growth length in the U-shaped overflow conduit, calculate the volume V2 of the circulating medium in the waste liquid collection tank, and calculate the total volume V3 = V1 + V2; SSS04, Compliance endpoint assessment, wherein the normal volume of the sample to be tested is V4, and the volume change rate of the sample to be tested is K=V3 / V4.

[0020] As a preferred embodiment of the present invention, the circulating medium is water, simulated body fluid, simulated blood, or simulated urine.

[0021] The present invention has the following beneficial effects: 1. This invention simulates a real physiological environment, supporting the simulation of physiological fluid flow under a constant temperature of 37℃. Temperature fluctuations during long-term testing are ≤0.5℃. It is compatible with both pulsed and continuous fluid flow modes, accurately reproducing the complex fluid flow state and long-term stress load conditions within the human body. This characteristic makes the test results closer to clinical reality, significantly improving the reliability of the assessment.

[0022] 2. This invention, through dynamic loading and structural response evaluation, allows the system to be set with a continuous operating cycle and target flow rate of over 72 hours, enabling the evaluation of the structural response of samples under long-term dynamic loading. Real-time flow monitoring using a non-contact flow meter, combined with valve adjustment, achieves targeted load simulation, providing precise data support for instrument performance optimization. The overall accuracy of this compliance testing system is within ±5%.

[0023] 3. This invention provides precise quantification of endpoint assessment. During the compliance endpoint assessment stage, a constant pressure is applied using a controllable pressurization device, and the volume of liquid overflow is measured using a U-shaped overflow conduit and a waste liquid collection tank. The volume change rate of the sample is then calculated. This quantitative indicator provides an intuitive and comparable assessment basis for device compliance.

[0024] 4. This invention features a closed structure and stable operation. The system adopts a closed structural design, combined with a PTFE test chamber and precision valve control, ensuring the stability and repeatability of the testing process. Simultaneously, the modular design facilitates operation and maintenance, reducing the impact of human error on the results.

[0025] 5. This invention is not only applicable to compliance testing of artificial blood vessels, but can also be extended to the verification and comparative studies of long-term implantable endovascular medical devices such as urinary stents and gastrointestinal nutrition catheters. Its flexible parameter adjustment capability meets the clinical needs of different devices.

[0026] 6. This invention integrates functions such as liquid injection, venting, circulation drive, pressure loading, and flow monitoring, simplifying the testing process. The integrated design of the constant temperature chamber further improves testing efficiency and shortens the research and development cycle.

[0027] 7. This invention is non-destructive and highly repeatable. Compared with traditional static pressure testing, this invention achieves non-destructive dynamic evaluation, avoiding the impact of sample damage on the results. At the same time, the highly repeatable testing process ensures data consistency, providing strong support for device registration testing and clinical applications. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a system for testing the compliance of artificial blood vessels according to the present invention.

[0030] The attached diagram lists the components represented by each number as follows: 1-Test chamber, 2-Inlet pipe, 3-Outlet pipe, 4-Inlet channel, 5-Outlet channel, 6-Pressure loading pipe, 7-Peristaltic pump, 8-T-way PVC hose, 9-Valve, 10-Sample to be tested, 11-Addition pipe, 12-Stop valve, 13-Overflow pipe, 14-Non-contact flow meter. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Specific Implementation Example 1: Please see Figure 1 As shown, the present invention is a system for testing the compliance of artificial blood vessels, comprising a test chamber 1, which can accommodate a sample 10 to be tested, and the test chamber 1 is provided with an inlet pipe 2 and an outlet pipe 3 communicating with the inner cavity of the sample 10. Both the inlet pipe 2 and the outlet pipe 3 are equipped with Luer connectors at their connection ends to the sample 10.

[0033] A main circulating fluid circuit includes an inlet channel 4 and an outlet channel 5 connected to the test chamber 1, as well as an external fluid circulation system connected to the inlet channel 4 and the outlet channel 5. The external fluid circulation system includes a peristaltic pump 7 and two three-way PVC hoses 8 connected to each other to simulate the fluid circulation environment inside the human body. The third ends of the two three-way PVC hoses 8 are respectively connected to the inlet pipe 2 and the outlet pipe 3.

[0034] A pressure loading tube 6 applies a constant rated pressure to the sample cavity during the endpoint evaluation phase via a controllable pressurization device. The controllable pressurization device includes a syringe with an infusion tubing fitted with a Luer female connector, and a Luer male connector at the end of the pressure loading tube 6.

[0035] Multiple valves 9 are used to control the opening and closing status of the liquid channels during the testing process. Specifically, a valve 9 is installed on each of the inlet pipe 2, outlet pipe 3, inlet channel 4, outlet channel 5, and pressure loading pipe 6.

[0036] A filling structure is provided, located at the top of the test chamber 1, for venting gas before testing. The filling structure includes a filling pipe 11 that extends through and is fixed to the top of the test chamber 1. A shut-off valve 12 is installed on the filling pipe 11.

[0037] An exhaust structure is provided, located at the top of the test chamber 1. The exhaust structure includes an overflow pipe 13 that runs through and is fixed to the top of the test chamber 1.

[0038] Among them, test chamber 1 is made of polytetrafluoroethylene, which has excellent chemical corrosion resistance and sealing properties.

[0039] Among them, a non-contact flow meter 14 is installed on the inlet pipe 2 and the inlet channel 4 respectively for real-time monitoring of flow.

[0040] A specific application of this embodiment is as follows: In actual testing, the sample 10 to be tested is first placed in the test chamber 1 and the test chamber 1 is sealed. The inlet pipe 2, outlet pipe 3, and pressure loading pipe 6 are then connected. Then, a circulating medium (such as water, simulated body fluid, simulated blood, or simulated urine, depending on the type of sample 10 to be tested; this compliance testing system is applicable to artificial blood vessels, urinary stents, gastrointestinal nutrition catheters, etc.) is injected into the test chamber 1 through the injection pipe 11, and the injection process is controlled by the shut-off valve 12. After the injection is completed, all valves 9 are opened, and the peristaltic pump 7 is started to circulate and vent air, ensuring that there are no air bubbles in the test chamber 1. Subsequently, the operating mode (pulse or continuous) of the peristaltic pump 7 is set as needed, and the operating cycle is set. During the long-term load operation phase, the flow rate is monitored in real time through the non-contact flow meter 14, and the valves 9 are adjusted as needed to achieve targeted load simulation. Specific Implementation Example 2: Based on the same technical concept, the second embodiment of this application provides a method for testing the compliance of artificial blood vessels, applied to the system for testing the compliance of artificial blood vessels in the first embodiment. The method for testing the compliance of artificial blood vessels includes completing an initial preparation phase, a long-term loading operation phase, and a compliance endpoint evaluation phase within a constant temperature chamber (set temperature 37°C). The entire testing process takes place in the middle of the constant temperature chamber, where the temperature of all equipment reaches a stable state. The temperature fluctuation of the tested components throughout the entire testing process is ≤0.5°C, simulating a body temperature testing environment with accurate and reliable results.

[0042] The initial preparation phase includes the following steps: S01, Injection: Inject the circulating medium into the test chamber 1 through the injection pipe 11.

[0043] S02. Circulation and venting: After the liquid level in test chamber 1 exceeds the height of inlet pipe 2 and outlet pipe 3, open all valves 9 and start the peristaltic pump 7 in the main circulating liquid circuit. After the pressure loading pipe 6 stably outputs circulating medium, close valve 9 on it. When inlet pipe 2 and inlet channel 4 no longer output air bubbles into test chamber 1, and test chamber 1 is completely free of air bubbles, close shut-off valve 12 and peristaltic pump 7, and then immediately close all valves 9. The closed structure design and precision valve control of the test chamber effectively reduce leakage and external interference during the test process. The impact of these factors on test accuracy is minimized, thereby indirectly improving the accuracy of compliance testing.

[0044] The long-term loading and running phase includes the following steps: SS01. After completing the initial preparation stage, open the inlet pipe 2, outlet pipe 3, inlet channel 4 and outlet channel 5, and turn on the peristaltic pump 7 to drive the circulating medium to circulate in the sample to be tested 10 and the test chamber 1.

[0045] SS02. Set the operating mode of peristaltic pump 7. Peristaltic pump 7 can switch between pulse or continuous operating modes to adapt to different clinical use environments of the device.

[0046] SS03. Flow monitoring: Flow rate is monitored in real time using non-contact flow meters 14 installed on inlet pipe 2 and inlet channel 4, respectively. Targeted load simulation is achieved by adjusting valves 9 on inlet pipe 2 and inlet channel 4, respectively. The non-contact flow meters used in the system can monitor flow rate in real time and accurately. These flow meters have high accuracy, with an error range of ±1% to ±2%. This high-precision monitoring provides a reliable data foundation for subsequent structural response assessment and compliance calculations.

[0047] SS04. Set the operating cycle and set the peristaltic pump 7 to operate for more than 72 hours. The compliance endpoint assessment phase includes the following steps: SSS01. After completing the long-term loading and operation phase, install the overflow module, insert the U-shaped overflow conduit into the overflow pipe 13, and place the waste liquid collection tank directly below the output end of the U-shaped overflow conduit.

[0048] SSS02, close valves 9 on inlet pipe 2, outlet pipe 3, inlet channel 4 and outlet channel 5, connect the controllable pressurization device to the upper end of pressure loading pipe 6, and push at constant pressure.

[0049] SSS03. Measure the liquid overflow length, measure and calculate the volume V1 of the liquid column growth length in the U-shaped overflow conduit, calculate the volume V2 of the circulating medium in the waste liquid collection tank, and calculate the total volume V3 = V1 + V2.

[0050] SSS04, Compliance endpoint assessment: The normal volume of the test sample 10 is V4, and the volume change rate of the test sample 10 is K=V3 / V4.

[0051] The circulating medium is water, simulated body fluid, simulated blood, or simulated urine.

[0052] In actual operation, the initial preparation phase involves completing liquid injection and circulation venting. Following this, the long-term loading operation phase begins. The peristaltic pump 7's operating mode and cycle are set according to the testing requirements, and the flow rate is monitored and adjusted in real time. After the long-term operation concludes, the compliance endpoint assessment phase commences. This involves installing an overflow module, closing relevant valves, applying constant pressure, and measuring the liquid overflow length and volume. Finally, the volume change rate K of the test sample 10 is calculated to assess its compliance.

[0053] During the compliance endpoint assessment phase, a constant pressure is applied using a controlled pressurization device (such as a syringe connected to a pressure loading tube via an infusion tubing with a Luer female connector and a Luer male connector at the end of the pressure loading tube), and the volume of liquid overflow is precisely measured using a U-shaped overflow conduit and a waste collection tank. This quantitative assessment method has high accuracy because the measurement error of the U-shaped overflow conduit is typically small, and the volume measurement of the waste collection tank is also relatively accurate.

[0054] Considering the high accuracy of the non-contact flow meter, the stability of the closed structure of the test chamber, and the accuracy of the endpoint assessment method using the overflow pipe and controllable pressurization device, the overall accuracy of this compliance testing system is within ±5%.

[0055] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0056] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A system for testing the compliance of artificial blood vessels, characterized in that, include: A test chamber (1) is provided, which can accommodate the sample to be tested (10), and the test chamber (1) is provided with an inlet pipe (2) and an outlet pipe (3) that communicate with the inner cavity of the sample to be tested (10). A main circulating liquid circuit, the main circulating liquid circuit including an inlet channel (4) and an outlet channel (5) connected to the test chamber (1) and an external liquid circulation system connected to the inlet channel (4) and the outlet channel (5); The external liquid circulation system includes a peristaltic pump (7) and two three-way PVC hoses (8) connected to each other to simulate the liquid circulation environment in the human body; the third ends of the two three-way PVC hoses (8) are respectively connected to the inlet pipe (2) and the outlet pipe (3). A pressure loading tube (6) applies a constant rated pressure to the sample cavity during the endpoint evaluation stage via a controllable pressurization device; Multiple valves (9) are used to control the opening and closing status of the liquid passage in the test process; A filling structure is provided at the upper end of the test chamber (1) for venting gas before testing; An exhaust structure is provided at the upper end of the test chamber (1).

2. The system for testing the compliance of artificial blood vessels according to claim 1, characterized in that, The test chamber (1) is made of polytetrafluoroethylene.

3. The system for testing the compliance of artificial blood vessels according to claim 2, characterized in that, A valve (9) is provided on each of the inlet pipe (2), outlet pipe (3), inlet channel (4), outlet channel (5) and pressure loading pipe (6).

4. The system for testing the compliance of artificial blood vessels according to claim 3, characterized in that, The controllable pressurization device includes a syringe, on which an infusion tube with a Luer female connector is installed, and the end of the pressure loading tube (6) is provided with a Luer male connector.

5. The system for testing the compliance of artificial blood vessels according to claim 4, characterized in that, The filling structure includes a filling pipe (11) that passes through and is fixed to the top of the test chamber (1); a shut-off valve (12) is installed on the filling pipe (11).

6. The system for testing the compliance of artificial blood vessels according to claim 5, characterized in that, The exhaust structure includes an overflow pipe (13) that runs through and is fixed to the top of the test chamber (1).

7. The system for testing the compliance of artificial blood vessels according to claim 6, characterized in that, A non-contact flow meter (14) is installed on the inlet pipe (2) and the inlet channel (4).

8. A method for testing the compliance of artificial blood vessels, characterized in that, The system for testing the compliance of artificial blood vessels as described in claim 7 includes an initial preparation phase, a long-term loading operation phase, and a compliance endpoint assessment phase all performed in a constant temperature chamber. The initial preparation phase includes the following steps: S01, Injection: Inject the circulating medium from the injection tube (11) into the test chamber (1); S02. Circulate exhaust. After the liquid level in the test chamber (1) exceeds the height of the inlet pipe (2) and the outlet pipe (3), open all the valves (9), start the peristaltic pump (7) in the main circulating liquid circuit, and close the valve (9) on the pressure loading pipe (6) after it stably outputs the circulating medium. When the inlet pipe (2) and the inlet channel (4) no longer output bubbles into the test chamber (1) and there are no bubbles in the test chamber (1), close the shut-off valve (12) and the peristaltic pump (7), and then close all the valves (9). The long-term loading and running phase includes the following steps: SS01. After completing the initial preparation stage, open the inlet pipe (2), outlet pipe (3), inlet channel (4) and outlet channel (5), and turn on the peristaltic pump (7) to drive the circulating medium to circulate in the sample to be tested (10) and the test chamber (1); SS02. Set the operating mode of the peristaltic pump (7). The peristaltic pump (7) can switch between pulse or continuous operating modes to adapt to the clinical use environment of different devices. SS03. Flow rate monitoring: The flow rate is monitored in real time by non-contact flow meters (14) installed on the inlet pipe (2) and the inlet channel (4) respectively. Targeted load simulation is achieved by adjusting the valves (9) on the inlet pipe (2) and the inlet channel (4) respectively. SS04. Set the operating cycle and set the long-term operating time for the peristaltic pump (7); The compliance endpoint assessment phase includes the following steps: SSS01. After completing the long-term loading and running phase, install the overflow module, insert the U-shaped overflow conduit into the overflow pipe (13), and place the waste liquid collection tank directly below the output end of the U-shaped overflow conduit. SSS02, close the valves (9) on the inlet pipe (2), outlet pipe (3), inlet channel (4) and outlet channel (5), connect the controllable pressurization device to the upper end of the pressure loading pipe (6), and push at constant pressure; SSS03, Measure the liquid overflow length, measure and calculate the volume V1 of the liquid column growth length in the U-shaped overflow conduit, calculate the volume V2 of the circulating medium in the waste liquid collection tank, and calculate the total volume V3 = V1 + V2; SSS04, Compliance endpoint assessment, the normal volume of the test sample (10) is V4, and the volume change rate of the test sample (10) is K=V3 / V4.

9. The method for testing the compliance of artificial blood vessels according to claim 8, characterized in that, The circulating medium is water, simulated body fluid, simulated blood, or simulated urine.

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