Artificial catheter mechanical compliance tester and testing method

Abstract

The invention belongs to the technical field of medical biological materials and medical instrument performance testing, and particularly discloses an artificial catheter mechanical compliance tester and a testing method. The mechanical compliance tester for the artificial catheter comprises a mounting module, a liquid supply module, a pressure regulating module, a laser measuring instrument and a compliance test host PLC (Programmable Logic Controller). The mounting module comprises a fixing part and an adjusting part and is used for mounting the artificial catheter in the test chamber; the liquid supply module comprises a constant-temperature solution tank for providing a circulating solution for the test chamber; the pressure regulating module comprises an oscillation generator for enabling the artificial catheter to generate periodic expansion and contraction and a pressure pump for regulating the internal pressure of the artificial catheter; the laser measuring instrument comprises a laser measuring probe and a mounting rack which can adjust the position of the laser measuring probe to enable the laser measuring probe to be aligned with the artificial catheter for diameter measurement. The tester quantitatively detects the compliance of the artificial blood vessel under a continuous flow state, can continuously measure the same sample, and is high in accuracy and good in repeatability.

Description

Technical Field

[0001] The invention belongs to the technical field of performance testing of medical biomaterials and medical devices, and particularly relates to an artificial catheter mechanical compliance tester and a testing method. The artificial catheter mechanical compliance tester is suitable for compliance testing of artificial catheters. Background Art

[0002] The compliance of an artificial catheter is the ability of the catheter to change in volume or shape when subjected to internal pressure, and generally reflects its flexibility, expandability, and adaptability to pressure changes. This characteristic is crucial in medical applications and directly affects the function, safety, and patient comfort of the catheter. High compliance means that the catheter is soft and easily deformed, which can buffer pressure fluctuations and reduce irritation to surrounding tissues (such as blood vessels and urethra), but may lead to structural instability due to excessive expansion. Low compliance means that the catheter is more rigid and can maintain its shape and patency, but may increase the risk of tissue damage (such as friction and compression). Therefore, measuring and matching the compliance of artificial catheters is an important issue.

[0003] Conventional compliance testing devices typically use a pump to pump water into an artificial catheter, then measure its dimensions using a measuring component. This test environment involves water only inside the catheter, not outside. This significantly differs from the actual environment in which the catheter is used, impacting measurement accuracy. Furthermore, conventional devices typically attach the artificial catheter to a rubber tube (e.g., CN101393095A) and then clamp the tube at both ends. This method maintains the catheter in a well-extended state for easy dimensional measurement. However, the rubber tube also exhibits mechanical responsiveness, which significantly affects the accuracy of compliance measurements. Furthermore, conventional testing devices struggle to meet the compliance measurement requirements for artificial catheters of varying lengths. Summary of the Invention

[0004] To solve the above problems, the present invention provides an artificial catheter mechanical compliance tester and testing method, which can accurately test the mechanical compliance of artificial catheters in a device that continuously flows and simulates the microenvironment of tissue fluid (water, PBS, blood, bile, urine, etc.).

[0005] In order to achieve the above object, the specific technical solutions adopted by the present invention are as follows:

[0006] In a first aspect, the present invention provides an artificial catheter mechanical compliance tester, comprising:

[0007] A test chamber, provided with a liquid inlet and a liquid outlet;

[0008] An installation module is used to install the artificial catheter in the test chamber. The module includes a fixing member and an adjusting member that penetrate from both sides of the test chamber. The two ends of the artificial catheter are tied and fixed to the inner sides of the fixing member and the adjusting member respectively. The internal hollow space of the fixing member is connected to the artificial catheter. The adjusting member adjusts the extension state of the artificial catheter by translation.

[0009] a liquid supply module, comprising a constant temperature solution tank for providing a circulating solution to the test chamber, wherein the constant temperature solution tank is connected to a liquid inlet and a liquid outlet of the test chamber respectively through pipes;

[0010] a pressure regulating module comprising an oscillation generator connected to the outer end of the fixing member via a pipe for causing the artificial catheter to periodically expand and contract (simulating blood pumping) and a pressure pump disposed in the constant temperature solution tank and connected to the pipe connecting the fixing member and the oscillation generator for regulating the internal pressure of the artificial catheter;

[0011] The laser measuring instrument comprises a laser measuring probe and a mounting frame which can adjust the position of the laser measuring probe so as to align the laser measuring probe with an artificial catheter for diameter measurement.

[0012] Furthermore, the adjusting member includes a connecting rod, a load rope and a load assembly; the connecting rod is slidably connected to the test chamber, and its outer end is connected to the load rope. The load assembly includes a shell and a rotating wheel and a weight arranged in the shell, and the outer end of the load rope passes around the rotating wheel and is downwardly connected to the weight.

[0013] Furthermore, the adjusting member also includes a locking member, which is a sleeve structure, the bottom of which is fixedly connected to the shell, the tube body is sleeved on the connecting rod, and a first threaded hole is formed through the tube body for inserting a screw to lock the connecting rod.

[0014] Furthermore, the liquid supply module also includes a circulating peristaltic pump, a heater and a temperature sensor arranged in the constant temperature solution tank.

[0015] Furthermore, the oscillation generator includes a first motor, a push block arranged on the output shaft of the first motor, and a balloon arranged on the outside of the push block, which is squeezed by the end face of the pushed block to periodically expand and contract; the balloon is elastic and non-permeable, and has an opening, which is connected to the fixing member through a pipe.

[0016] Furthermore, the pressure regulating module further includes a pressure sensor provided on a connecting pipe between the fixing member and the oscillation generator.

[0017] Furthermore, in the laser measuring instrument, the mounting frame includes a translation portion, a lifting portion, and a probe mounting member;

[0018] The translation portion includes a base and a translation block mounted on the base, wherein a horizontal screw is provided in the base, and the translation block is driven by the horizontal screw to move in a direction parallel to the installation direction of the artificial catheter;

[0019] The lifting part includes a screw rod frame and a lifting block sleeved on the screw rod frame, the screw rod frame is provided with a vertical screw, and the lifting block is driven by the vertical screw to move up and down;

[0020] The probe mounting piece is fixed on the side of the lifting block, with its length direction perpendicular to the installation direction of the artificial catheter, and the laser measuring probe is installed on one side of the probe mounting piece.

[0021] Furthermore, the probe mounting part is a 4040 aluminum profile, which has a horizontal slide groove along the length direction. A second threaded hole is provided on the surface of the laser measurement probe near the two side edges for screws to pass through. The head of the screw is placed in the horizontal slide groove and can move in the slide groove.

[0022] Furthermore, the laser measuring instrument further includes a laser measuring instrument PLC; the artificial catheter mechanical compliance tester further includes a compliance test host PLC.

[0023] In a second aspect, the present invention provides a method for testing the mechanical compliance of an artificial catheter, which is performed using the above-mentioned artificial catheter mechanical compliance tester, and specifically comprises the following steps:

[0024] S1. Add simulated tissue fluid to the constant temperature solution tank;

[0025] S2. Turn on the heater in the constant temperature solution tank to heat the solution to the desired temperature;

[0026] S3. Install the artificial catheter into the sealed test chamber and adjust the laser spot emitted by the laser measurement probe so that it illuminates the center of the catheter sample.

[0027] S4. After the sample is loaded, adjust the length of the load rope and apply a longitudinal load to the end of the load rope to ensure that the artificial catheter is properly extended.

[0028] S5. Start the circulating peristaltic pump to draw the constant temperature solution from the constant temperature solution tank into the test chamber, forming a circulating flow. The circulating peristaltic pump is used to adjust the pressure in the test chamber and the linear velocity of the pressurized solution. The catheter sample is immersed and adapted before testing.

[0029] S6. Start the pressure pump to adjust the solution pressure to the desired value and pump it into the artificial catheter. This pressure is the P1 value.

[0030] S7. Set the number of tests and test frequency in the laser measuring instrument PLC. You can select multiple measurements at the same location or adjust the position of the laser measuring probe through the mounting bracket to perform multiple measurements at different locations.

[0031] During the test, turn on the oscillator and squeeze the airbag at a frequency of 60 ± 10 times / min, causing the sample to cyclically expand and contract, thereby increasing the pressure from P1 to P2 and back again.

[0032] S9. The laser measuring instrument measures the outer diameter of the artificial catheter under pressure P1 and P2, and the inner radius R of the artificial catheter under P1 and P2 is obtained based on the wall thickness. p1 and R p2 , the compliance is calculated according to the following formula:

[0033] C=(R p2 -R p1 ) / (R p1 ×(P2-P1))×10 4 ;

[0034] Where: C—compliance, %; P1—low pressure value, unit is mmHg; P2—high pressure value, unit is mmHg; R p1 —Inner radius after low pressure; R p2 —Inner radius after high pressure application;

[0035] S10. The compliance test host PLC records multiple compliance measurement data, removes abnormal data, and calculates the average value of the remaining valid data to obtain the mechanical compliance performance of the artificial catheter.

[0036] Furthermore, in step S1, the constant temperature solution tank has a volume of 30 liters, a temperature control accuracy of ±0.1 to 0.5°C, and a temperature control range of 18 to 50°C; 20 to 25 L of simulated tissue fluid is added to the constant temperature solution tank.

[0037] Furthermore, in step S4, a pulley is passed around the end of the load rope, and a weight of 0.294 to 0.588 N (suspended mass of 30 to 60 g) is hung to form a longitudinal load, so that the catheter sample has a good extension shape in the immersion solution, which facilitates the laser measuring instrument to measure its outer diameter change.

[0038] Furthermore, in step S6, the pressure in the test chamber is adjusted in a range of 1 kPa to 25 kPa, and the linear velocity of the buffer solution is adjusted in a range of 10 to 100 mL / min.

[0039] Furthermore, in step S10 , the compliance deviation is effectively determined as follows: the deviation of the measured multiple sets of data is 0.6 to 1.4 with the average value as the reference, and values exceeding this range are eliminated as abnormal data.

[0040] In a third aspect, the present invention provides the application of the above-mentioned artificial catheter mechanical compliance tester or artificial catheter mechanical compliance testing method in the mechanical compliance testing of artificial blood vessels, biliary stents and urethral tubes.

[0041] The present invention has the following beneficial effects:

[0042] 1. The liquid supply module circulates liquid into the test chamber, so that the outside of the artificial catheter is also in a liquid environment. At the same time, the pressure regulating module composed of a pressure sensor, a pressure pump and an oscillation generator is used to fill the interior of the artificial catheter with liquid and provide periodic pressure changes, maximizing the simulation of the human physiological state of the blood vessels. Continuous measurements are performed in this environment, effectively improving the accuracy of the artificial catheter compliance test.

[0043] 2. The artificial catheter is loaded into the test chamber through an installation module composed of fixing parts and adjusting parts. The adjusting parts composed of connecting rods, load ropes, load components, and locking parts ensure that the artificial catheter is measured in a good extended state in the form of load adjustment. There is no need to tie the two ends of the artificial catheter and then insert a rubber tube to provide a certain support as in the existing technology. This ensures the extension state of the catheter while improving the accuracy of the measurement.

[0044] 3. The adjustment part not only ensures the good extension state of the catheter, but also can adapt to artificial catheters of different lengths by adjusting the position of the connecting rod and the length of the load rope, meeting the diverse measurement needs of artificial catheters.

[0045] 4. The structural optimization of the laser measuring instrument mounting frame enables multi-directional adjustment of the laser measuring probe position with high precision, ensuring that the laser position can be aligned with the catheter, thereby improving the reliability of the measurement results. It also facilitates measurement at different positions and adjustment of the measurement position when changing different samples, thereby improving test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 Schematic diagram of the simplified structure of the catheter compliance tester of the present invention.

[0047] Figure 2 It is a three-dimensional structural diagram of the catheter compliance tester of the present invention.

[0048] Figure 3 1 is a top view of the catheter compliance tester of the present invention.

[0049] Figure 4 It is a structural schematic diagram of the installation module in the catheter compliance tester of the present invention.

[0050] Figure 5 Schematic diagram of the structure of the oscillation generator in the catheter compliance tester of the present invention.

[0051] Figure 6 This is a schematic structural diagram of a mounting frame for mounting a laser measuring probe in the catheter compliance tester of the present invention.

[0052] Figure 7 This is a schematic diagram of the installation of the laser measurement probe in the catheter compliance tester of the present invention on the 4040 aluminum profile.

[0053] Figure 8 This is a schematic diagram of the laser measuring probe in the catheter compliance tester of the present invention emitting laser light to an artificial catheter.

[0054] In the figure: 1 - artificial catheter; 2 - test chamber, 21 - liquid inlet, 22 - liquid outlet; 3 - fixing part; 4 - adjusting part, 41 - connecting rod, 42 - load rope, 43 - load assembly, 44 - locking part, 431 - rotating wheel, 432 - weight, 433 - housing, 441 - first threaded hole; 5 - constant temperature solution tank; 6 - oscillation generator, 61 - balloon, 62 - push block, 63 - first motor; 7 - laser measuring instrument, 71 - laser measuring probe, 72 - mounting bracket, 73 - laser measuring instrument PLC, 74 - laser, 711 - second threaded hole, 721 - base, 722 - second motor, 723 - translation block, 724 - screw rack, 725 - handwheel, 726 lifting block, 727 - probe mounting part, 7271 - horizontal slide; 8 - compliance test host PLC. DETAILED DESCRIPTION

[0055] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0056] Example 1

[0057] This embodiment provides an artificial catheter mechanical compliance tester, the structure of which is as follows: Figure 1-3 As shown, it includes a test chamber 2, a mounting module, a liquid supply module, a pressure regulating module, a laser measuring instrument 7 and a compliance test host PLC 8.

[0058] The test chamber 2 is a set of sealed acrylic small grooves, which are detachable.

[0059] The installation module is used to install the artificial catheter 1 in the test chamber 2. The module includes a fixing member 3 and an adjusting member 4 that are respectively inserted from both sides of the test chamber 2. The two ends of the artificial catheter 1 are tied and fixed to the inner sides of the fixing member 3 and the adjusting member 4. The interior of the fixing member 2 is hollow and communicates with the artificial catheter 1. The adjusting member 4 is as shown in FIG. Figure 2 and 4As shown, it includes a connecting rod 41, a load rope 42, a load assembly 43 and a locking member 44; the connecting rod 41 is slidably connected to the test chamber 2, and its outer end is connected to the load rope 42. The load assembly 43 includes a shell 433 and a rotating wheel 431 and a weight 432 arranged in the shell 433. The outer end of the load rope 42 passes around the rotating wheel 431 and is downwardly connected to the weight 432. The weight 432 drives the connecting rod 41 to move horizontally and thus adjust the extension state of the artificial catheter 1; the locking member 44 is a sleeve structure, the bottom of which is fixedly connected to the shell 433, the tube body is sleeved on the connecting rod 41, and the tube body is provided with a first threaded hole 441 for inserting a screw to lock the connecting rod 41.

[0060] The liquid supply module provides a constant, stable circulating solution (water, PBS, blood, bile, urine, or other simulated tissue fluid) to test chamber 2. It includes a constant-temperature solution tank 5, a circulating peristaltic pump, a heater, and a temperature sensor located within the tank. The tank 5 is connected to the liquid inlet 21 and liquid outlet 22 of test chamber 2 via pipes. The heater and temperature sensor maintain a constant temperature within the tank 5, while the circulating peristaltic pump delivers the solution to test chamber 2.

[0061] The pressure regulating module includes an oscillation generator 6 connected to the outer end of the fixing member 3 through a pipe for causing the artificial catheter 1 to expand and contract periodically, a pressure pump arranged in the constant temperature solution tank 5 and connected to the connecting pipe between the fixing member 3 and the oscillation generator 6 for regulating the internal pressure of the artificial catheter 1, and a pressure sensor arranged on the connecting pipe between the fixing member 3 and the oscillation generator 6. The oscillation generator 6 is as follows. Figure 5 As shown, it includes a first motor 63, a push block 62 arranged on the output shaft of the first motor 63, and a balloon 61 arranged on the outside of the push block 62 and squeezed by the end face of the pushed block 62 to periodically expand and contract. The bottom of the push block 62 is slidably connected to a base provided with a guide rail to limit and guide the push block 62 to improve the stability of the expansion and compression of the balloon 61; the balloon 61 has an opening, which is connected to the fixing member 3 through a pipe, so that the artificial catheter 1 undergoes periodic pressure changes under the influence of the balloon 61.

[0062] The laser measuring instrument 7 includes a laser measuring probe 71, a mounting frame 72 for adjusting the position of the laser measuring probe 71 so that the laser measuring probe 71 is aligned with the artificial catheter 1 for diameter measurement, and a laser measuring instrument PLC 73. Figure 6 As shown, it includes a translation part, a lifting part and a probe mounting part 727, and the specific structure is as follows:

[0063] The translation portion includes a base 721 and a translation block 723; a horizontal screw is provided in the base 721, and the horizontal screw is driven by a second motor 722, driving the screw nut sleeved on the horizontal screw to move in a direction parallel to the installation direction of the artificial catheter 1; the translation block 723 is sleeved on the base 721, and the bottom is fixedly connected to the screw nut on the horizontal screw and is driven to translate thereby.

[0064] The lifting part includes a screw rack 724 and a lifting block 726; a vertical screw is provided inside the screw rack 724, and a handwheel 725 is provided on the top of the vertical screw. Turning the handwheel 725 drives the vertical screw and drives the screw nut mounted thereon to move vertically; the lifting block 726 is mounted on the screw rack 724, and the inner side is fixedly connected to the screw nut on the vertical screw and is driven to lift and lower.

[0065] The probe mounting member 727 is fixed to the side of the lifting block 726, and its length direction is perpendicular to the installation direction of the artificial catheter 1. The laser measurement probe 71 is installed on one side. The surface of the laser measurement probe 71 is provided with a second threaded hole 711 near the edge of both sides for screws to penetrate and install the laser measurement probe 71 on the probe mounting member 727. The probe mounting member 727 can be Figure 6 The L-shaped plate shown in FIG, at this time, the laser measurement probe 71 is fixedly connected to the probe mounting member 727 by screws and nuts. As an example, the probe mounting member 727 can also be as shown in FIG. Figure 7 The 4040 aluminum profile shown in the figure is now slidably connected to the laser measuring probe 71 and the probe mounting member 727: the 4040 aluminum profile has a horizontal slide groove 7271 along the length direction, and after the two second threaded holes 711 of the laser measuring probe 71 are inserted with screws, the heads of the screws are placed in the horizontal slide grooves 7271, and the laser measuring probe 71 is adjusted on the y-axis by sliding the screws in the horizontal slide grooves 7271. The second motor 722 is started to move the probe on the x-axis, and the hand wheel 725 is turned to move the probe on the z-axis. At this time, the laser measuring probe 71 can be adjusted in three directions. The position of the laser measuring probe 71 is adjusted until the laser it emits is aligned with the artificial catheter 1 ( Figure 8 ) to measure the outer diameter of the catheter.

[0066] The laser measuring instrument PLC 73 is electrically connected to the laser measuring probe 71 and the mounting bracket 72 , and is used to control the opening and closing of the laser measuring probe 71 and the position adjustment of the laser measuring probe by the mounting bracket 72 .

[0067] The compliance test host PLC 8 is electrically connected to the peristaltic pump, heater, temperature sensor, pressure pump, pressure sensor, oscillator 6, and laser measuring instrument 7 to control the operation of these components and data transmission. The compliance test host PLC 8 has a touch screen that displays the upper and lower limits of the test solution pressure, the pressure in the test chamber 2 and the linear velocity of the pressurized solution, the test temperature, the number of tests, and the test frequency. Upon test completion, the compliance value (unit: % / 100 mmHg) is automatically displayed.

[0068] Example 2

[0069] This embodiment provides a specific example of using the compliance tester of Example 1 to perform mechanical compliance testing of an artificial catheter, as follows:

[0070] S1. Add 25L of PBS buffer solution to the constant temperature solution tank 5;

[0071] S2. Set the solution temperature on the compliance test host PLC 8 and turn on the heater placed in the constant temperature solution tank 5 by controlling the temperature, preheat for 30 minutes, so that the water tank temperature reaches 37 ° C;

[0072] S3. A small-caliber electrospun artificial blood vessel was selected as the artificial catheter sample, having an outer diameter of 2.8 mm, a length of 40 mm, and a wall thickness of 0.4 mm. The sample was fixed in the test chamber by a fixing member 3 and an adjusting member 4, and the position of the laser spot was adjusted by the three-way adjustment function of the laser measuring instrument 7 mounting bracket 72 so that it was exactly in the middle of the sample.

[0073] S4. After the sample is loaded, a longitudinal preload of 0.588N (60g) is suspended at the end of the load link 42;

[0074] S5. Start the peristaltic pump and draw 37°C water from the constant temperature water tank 5 into the test chamber 2. Allow the sample to soak at 37°C for a period of time before testing. The temperature is controlled at 37°C, the pressure in the test chamber is 24.7 kPa, and the linear velocity of the buffer solution is 30 mL / min. The peristaltic pump and temperature sensor are suspended in the liquid to ensure a constant solution temperature and form a circulating flow.

[0075] S6. Set the PBS buffer solution pressure group P1-P2 of the test on the compliance test host PLC 8 at 10.7kPa-16.0kPa, start the pressure pump to adjust the solution pressure to the P1 value, and pump it into the artificial catheter 1;

[0076] S7. After the temperature reaches 37°C, set the laser measuring instrument PLC 73 to automatically test the same position for 10 consecutive cycles, with an interval of 120 seconds between each test.

[0077] S8. After the test is started, the push block 62 squeezes the airbag 61 at a frequency of 60 times / min, with a frequency of 150 oscillations, causing the sample to cyclically expand and contract, thereby increasing the pressure from P1 (10.7 kPa) to P2 (16.0 kPa) and switching back and forth;

[0078] S9. The compliance test host PLC 8 drives the laser measuring instrument 7 to automatically test. The system automatically tests, calculates, and transmits the measurement results. The laser measuring instrument 7 measures the outer diameter of the artificial catheter 1 under pressures P1 and P2, and obtains the inner radius R of the artificial catheter under pressures P1 and P2 based on the wall thickness. p1 and R p2 , the compliance test host PLC 8 calculates the compliance according to the following formula:

[0079] C=(R p2 -R p1 ) / (R p1 ×(P2-P1))×10 4 ;

[0080] Where: C—compliance, %; P1—low pressure value, unit is mmHg; P2—high pressure value, unit is mmHg; R p1 —Inner radius after low pressure; R p2 —Inner radius after high pressure application;

[0081] S10. The 10 measured results showed 4.23%, 3.78%, 3.40%, 7.91%, 4.99%, 5.68%, 8.70%, 4.80%, 3.79%, and 3.94%, of which 7.91% and 8.70% were abnormal data and were automatically eliminated. The calculated average compliance value was 4.33% / 100mmHg.

[0082] In summary, the tester of the present invention approximately simulates the cyclic expansion process of blood vessels caused by the pressure exerted by the heart's cyclical pumping of blood on human blood vessels. By setting conditions such as temperature, solution pressure, cyclic pressure oscillations, and specific tissue solutions, the compliance performance of artificial blood vessels can be detected under continuous flow conditions, enabling continuous measurement of the same sample with high accuracy and good repeatability.

[0083] This specific implementation is merely an explanation of the present invention and is not a limitation of the present invention. Any changes made by those skilled in the art after reading the specification of the present invention will be protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. An artificial catheter mechanical compliance tester, characterized in that: include: A test chamber (2) is provided with a liquid inlet (21) and a liquid outlet (22); An installation module is used to install an artificial catheter (1) in the test chamber (2), the module comprising a fixing member (3) and an adjusting member (4) respectively inserted from both sides of the test chamber (2), the two ends of the artificial catheter (1) being tied and fixed to the inner sides of the fixing member (3) and the adjusting member (4), respectively; the interior of the fixing member (2) is hollow and communicates with the artificial catheter (1); the adjusting member (4) adjusts the extension state of the artificial catheter by translation; A liquid supply module comprises a constant temperature solution tank (5) for providing a circulating solution to the test chamber (2), wherein the constant temperature solution tank (5) is connected to a liquid inlet (21) and a liquid outlet (22) of the test chamber (2) via pipelines; A pressure regulating module comprises an oscillation generator (6) connected to the outer end of the fixing member (3) via a pipe for causing the artificial catheter (1) to generate periodic expansion and contraction, and a pressure pump arranged in the constant temperature solution tank (5) and connected to the connecting pipe between the fixing member (3) and the oscillation generator (6) for regulating the internal pressure of the artificial catheter (1); The laser measuring instrument (7) comprises a laser measuring probe (71) and a mounting frame (72) capable of adjusting the position of the laser measuring probe (71) so as to align the laser measuring probe (71) with the artificial catheter (1) for diameter measurement.

2. The artificial catheter mechanical compliance tester according to claim 1, characterized in that: The adjusting member (4) comprises a connecting rod (41), a load rope (42), and a load assembly (43); the connecting rod (41) is slidably connected to the test chamber (2), and its outer end is connected to the load rope (42); the load assembly (43) comprises a housing (433) and a rotating wheel (431) and a weight (432) arranged in the housing (433); the outer end of the load rope (42) passes around the rotating wheel (431) and is downwardly connected to the weight (432).

3. The artificial catheter mechanical compliance tester according to claim 2, characterized in that: The adjusting member (4) further comprises a locking member (44), which is a sleeve structure, the bottom of which is fixedly connected to the housing (433), the tube body being sleeved on the connecting rod (41), and a first threaded hole (441) being provided through the tube body for inserting a screw to lock the connecting rod (41).

4. The artificial catheter mechanical compliance tester according to claim 1, characterized in that: The liquid supply module further comprises a circulating peristaltic pump, a heater and a temperature sensor arranged in the constant temperature solution tank (5).

5. The artificial catheter mechanical compliance tester according to claim 1, characterized in that: The oscillation generator (6) comprises a first motor (63), a push block (62) arranged on the output shaft of the first motor (63), and a balloon (61) arranged outside the push block (62) and configured to periodically expand and contract when squeezed by the end face of the pushed block (62); the balloon (61) has an opening, which is connected to the fixing member (3) through a pipe.

6. The artificial catheter mechanical compliance tester according to claim 1, characterized in that: The pressure regulating module further comprises a pressure sensor arranged on a connecting pipe between the fixing member (3) and the oscillation generator (6).

7. The artificial catheter mechanical compliance tester according to claim 1, characterized in that: In the laser measuring instrument (7), the mounting frame (72) includes a translation portion, a lifting portion, and a probe mounting member (727); The translation portion includes a base (721) and a translation block (723) mounted on the base (721); a horizontal screw is provided in the base (721); and the translation block (723) is driven by the horizontal screw to move in a direction parallel to the installation direction of the artificial catheter (1); The lifting part includes a screw rod frame (724) and a lifting block (726) mounted on the screw rod frame (724). A vertical screw is provided in the screw rod frame (724), and the lifting block (726) is driven by the vertical screw to move up and down. The probe mounting member (727) is fixed on the side of the lifting block (726), and its length direction is perpendicular to the installation direction of the artificial catheter (1). The laser measurement probe (71) is installed on one side of the probe mounting member.

8. The artificial catheter mechanical compliance tester according to claim 7, characterized in that: The probe mounting member (727) is a 4040 aluminum profile and has a horizontal slide groove (7271) along its length. A second threaded hole (711) is provided on the surface of the laser measuring probe (71) near the two side edges for screws to pass through. The head of the screw is placed in the horizontal slide groove (7271) and can move in the slide groove.

9. The artificial catheter mechanical compliance tester according to claim 1, characterized in that: The laser measuring instrument (7) further comprises a laser measuring instrument PLC (73); and the artificial catheter mechanical compliance tester further comprises a compliance test host PLC (8).

10. A method for testing the mechanical compliance of an artificial catheter, characterized in that: The method is carried out using the artificial catheter mechanical compliance tester according to any one of claims 1 to 9, and specifically comprises the following steps: S1. Adding simulated tissue fluid to the constant temperature solution tank (5); S2. Turn on the constant temperature solution tank (5) in the heater to heat the solution to the desired temperature; S3. The artificial catheter (1) is installed in a sealed test chamber (2), and the position of the laser spot emitted by the laser measurement probe (71) is adjusted so that it is irradiated in the middle of the catheter sample; S4. After the sample is loaded, adjust the length of the load link (42) and apply a longitudinal load at its end so that the artificial catheter extends well; S5. Start the circulating peristaltic pump to draw the constant temperature solution from the constant temperature solution tank (5) and fill the test chamber (2), forming a circulating flow. The pressure in the test chamber (2) and the linear velocity of the pressurized solution are adjusted by the circulating peristaltic pump. The catheter sample is immersed and adapted before testing; S6. Start the pressure pump to adjust the solution pressure to the desired value and pump it into the artificial catheter (1). This pressure is the P1 value; S7. Set the number of tests and the test frequency in the laser measuring instrument PLC (73); S8. During the test, the oscillator (6) is turned on, and the push block (62) squeezes the airbag (61) at a frequency of 60±10 times / min, causing the sample to cyclically expand and contract, thereby increasing the pressure from P1 to P2 and reciprocating; S9. The laser measuring instrument (7) measures the outer diameter of the artificial catheter (1) under pressure P1 and P2, and the inner radius R of the artificial catheter under P1 and P2 is obtained according to the wall thickness. p1 and R p2 , the compliance is calculated according to the following formula: C=(R p2 -R p1 ) / (R p1 ×(P2-P1))×10 4 ; Where: C—compliance, %; P1—low pressure value, unit is mmHg; P2—high pressure value, unit is mmHg; R p1 —Inner radius after low pressure; R p2 —Inner radius after high pressure application; S10. The compliance test host PLC (8) records multiple compliance measurement data, removes abnormal data, and calculates the average value of the remaining valid data to obtain the mechanical compliance performance of the artificial catheter (1).

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