Heart valve prosthesis steady-state flow testing device and testing method

Abstract

The invention discloses a steady-state flow testing device and method for an artificial heart valve. Relates to improvement of a steady-state flow testing system technology of the artificial heart valve. The technical problems that an existing testing device is unstable in operation, unreliable in performance, low in precision, not easy to replace a tested valve, complex in operation and the like are solved. According to the device, an energy storage medium box is connected with an inlet of a throttling branch and a second valve in parallel, the second valve is connected with an inlet of a valve testing loop, an outlet of the valve testing loop is connected with a forward flow testing loop A and a backflow testing loop B in parallel through valves, and the forward flow testing loop A and the backflow testing loop B are further connected with an outlet of the throttling branch and a medium storage box. And aiming at the front flow characteristic and the back flow characteristic, a test channel is set to be a switchable channel with two orders of magnitude, so that the data error is reduced. The tested valve does not need to be replaced by dismounting the pipeline. The forward flow nozzle and the backflow nozzle which are connected in parallel are adopted, the nozzles do not need to be replaced, two tests can be achieved on one set of testing equipment, the working efficiency is effectively improved, and the testing cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical test equipment, and in particular relates to an improvement to the steady-state flow test system technology of an artificial heart valve. Background Art

[0002] At present, artificial heart valve replacement is an important treatment for end-stage heart valve disease. However, existing artificial heart valves still have many technical bottlenecks in design, materials and manufacturing processes, resulting in a certain gap between their functional performance and the body's natural valves. Importantly, after the artificial heart valve is implanted in the human body, its hemodynamic characteristics are difficult to directly test. Hemodynamic characteristics are crucial for the normal functioning of artificial heart valves. They are related to whether the valve can effectively simulate the function of a normal heart valve and ensure the normal flow of blood in the heart. If the hemodynamic characteristics are abnormal, serious complications such as blood reflux and thrombosis may occur. Therefore, it is of great clinical significance to establish a complete in vitro testing system before clinical application to conduct a comprehensive and accurate evaluation of the working performance of artificial heart valves.

[0003] According to relevant technical regulations in this field, steady-state flow testing is an indispensable core link in the performance evaluation system of artificial heart valves. Steady-state flow testing is divided into forward flow testing and reflux testing. The forward flow test simulates the quasi-steady flow state during the peak period of ventricular ejection and tests the forward flow resistance performance of the valve; this resistance performance directly affects the load on the heart during the ejection process. If the resistance is too large, the heart needs to overcome greater resistance to push blood through the valve, which will further increase the burden on the heart. The reflux test simulates the leakage state after the valve is completely closed and measures the closing quality of the valve. Under normal circumstances, the heart valve should be able to effectively prevent blood from flowing back after closing, and the reflux test can accurately measure the closing quality of the valve. If there is a leakage problem in the valve, it will cause blood to flow back, affecting the normal blood circulation and function of the heart.

[0004] Currently, most steady-state flow testing devices for artificial heart valves still use a traditional approach, where test conditions are achieved by adjusting the liquid level. These traditional testing systems suffer from poor operational stability, insufficient performance reliability, and cumbersome operational procedures. Furthermore, the need to change valves of different specifications during testing, as well as switching between forward and reverse flow testing, requires nozzle replacement, a complex process that significantly impacts testing efficiency.

[0005] Furthermore, the patent document "CN220293713U, A Steady-State Flow Test System for Heart Valve" proposes a technical solution for a test system to understand the hemodynamic characteristics of artificial heart valves. The patent document claims that the test system can simultaneously measure the pressure differential and regurgitant leakage of an isolated heart valve, as well as the pressure differential and leakage flow of a calibrated standard nozzle. The calibrated standard nozzle serves as a comparison, calculating the acceptable accuracy tolerance by obtaining the pressure differential of the standard nozzle. The data measured using the calibrated standard nozzle ensures reasonable and reliable test data for the pressure differential and regurgitant leakage of the isolated heart valve, providing realistic experimental data support for the design of valve repair devices. However, after reading the entire text, we believe that the patent document has the following technical problems: First, in this technical solution, valve replacement is very complicated, and the entire pipeline needs to be removed to remove the stent that clamps the valve; second, the nozzles for forward flow and reflux tests are different, and the nozzles need to be replaced when switching between tests; replacing the nozzle also requires removing the pipeline, which is more cumbersome, and when the pipeline is removed, the medium in the pipeline will also be vented; third, during the forward flow and reflux tests, due to the large transvalvular pressure difference at both ends of the valve, the two are at different orders of magnitude. If the technical solution of this document is followed, it is difficult to obtain accurate pressure data.

[0006] Therefore, how to design a test system that can adapt to process detection of two different orders of magnitude of forward flow and backflow to improve test stability, reliability and accuracy, and facilitate sample replacement has become a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0007] In response to the above shortcomings, the present invention provides an artificial heart valve steady-state flow testing device and testing method, which solves many technical problems of existing testing devices, such as unstable operation, unreliable performance, low accuracy, difficult replacement of the tested valve, and complex operation.

[0008] An artificial heart valve steady-state flow test device of the present invention comprises a control circuit and a circulation circuit, wherein the control circuit comprises a controller, and the circulation circuit comprises: a pump, an energy storage medium box, a valve test circuit, a forward flow test circuit, a backflow test circuit, a throttling branch, and a medium storage box; The pump is connected to the energy storage medium box, the energy storage medium box is connected in parallel to the inlet of the throttling branch and valve 2, the valve 2 is connected to the inlet of the valve test circuit, the outlet of the valve test circuit is connected in parallel to the forward flow test circuit and the reflux test circuit through valve 3, and the forward flow test circuit and the reflux test circuit are further connected to the outlet of the throttling branch and the medium storage box; A flow stabilizer is also provided in front of the second valve; The forward flow test circuit includes a forward flow nozzle, a pressure differential sensor 4, a valve 4 and a valve 5, wherein the valve 5, the forward flow nozzle and the valve 4 are connected in sequence, the pressure differential sensor 4 is connected in parallel with the forward flow nozzle; the pressure differential sensor 4 is connected to the controller; The backflow test circuit includes a backflow nozzle, a pressure differential sensor 3, a valve 6 and a valve 7, wherein the valve 7, the backflow nozzle and the valve 6 are connected in sequence, the pressure differential sensor 3 is connected in parallel with the backflow nozzle; the pressure differential sensor 3 is connected to the controller; The aperture of the forward flow nozzle opening of the forward flow nozzle is larger than the aperture of the reverse flow nozzle opening of the reverse flow nozzle.

[0009] Furthermore, the valve test circuit includes a valve test section, a solenoid valve 1, a solenoid valve 2, a pressure differential sensor 2 and a pressure differential sensor 1, a valve clamp, The solenoid valve 1, the pressure differential sensor 2 and the solenoid valve 2 are connected in sequence, and then connected in parallel with the pressure differential sensor 1 and the valve test section; The solenoid valve 1, the solenoid valve 2, the pressure difference sensor 2 and the pressure difference sensor 1 are respectively connected to the controller.

[0010] Furthermore, the valve test section includes a front section, a rear section and a valve clamp, the front section and the rear section are arranged opposite to each other, a clamping station adapted to the valve clamp is formed in front of the front section and the rear section, the valve clamp is clamped in the clamping station, the top surfaces of the front section and the rear section are respectively provided with exhaust valves, the opposite surfaces of the front section and the rear section are respectively provided with inflatable sealing rings corresponding to the valve clamp, and the inflatable sealing rings are connected to an air pump.

[0011] Furthermore, the valve clamp is a T-shaped clamp, which includes a sheet-like body and a hanging ring. A hole for accommodating the valve to be measured is opened in the center of the sheet-like body, and a silicone sleeve is also provided between the valve to be measured and the hole.

[0012] Furthermore, the valve clamp is a turntable clamp, which includes a turntable body and a turntable bracket. The turntable body is provided with a central rotating shaft, and the central rotating shaft is movably connected to the turntable bracket. The turntable bracket is fixed on the top surface of the front section or the rear section; a plurality of accommodating holes on the same circumference are arranged on the turntable body, and the outer circle of the valve to be measured is covered with a second silicone sleeve, and the second silicone sleeve is further arranged in the accommodating hole.

[0013] An axially movable positioning pin is provided on the turntable bracket, and a plurality of positioning holes are evenly distributed on the outer side of the turntable body around the central rotating shaft. The positioning pin is used to lock the turntable body.

[0014] Furthermore, the valve clamp is a snap-on clamp, which includes a snap-on clamp, an upper box cover, a lower box cover and a hinge. One side of the upper box cover and the lower box cover are respectively fixedly connected to the upper and lower hinge pieces of the hinge, and the other side of the upper box cover and the lower box cover are fixedly connected to the snap-on clamp. Semicircular holes for accommodating the valve to be tested are respectively provided between the upper box cover and the lower box cover, and positioning grooves are provided on the semicircular holes. The outer circular sleeve of the valve to be tested is provided with a positioning silicone sleeve that is adapted to the positioning grooves.

[0015] Furthermore, the valve clamp is an opening and closing clamp, which includes a gasket, a second buckle and a clamp box. The clamp box is a left and right opening and closing structure. A hole for accommodating the valve to be tested is provided in the center of the clamp box. A silicone sleeve three is provided between the valve to be tested and the hole. Gasket holes with a diameter larger than the hole are provided on both sides of the clamp box, and the gasket is provided in the gasket hole.

[0016] For example, a method for testing an artificial heart valve using a steady-state flow testing device of the present invention includes placing the artificial heart valve into a valve fixture, starting the system, and then performing the following steps: 1) Forward flow test, 1.1) Preparation before testing, 1.1.1) Install the valve to be tested into the valve fixture in the forward direction, fix the valve fixture in the valve test section, and seal the sealing position of the valve test section by stepping on the air pump. 1.1.2) Fill the circulation pipeline with liquid and open all valves. 1.1.3) Valve control, Close valves 6 and 7 to disconnect the backflow test circuit and prepare for the forward flow test. 1.2) Start the test. 1.2.1) Parameter settings, Select the specifications of the valve to be tested and select the test flow rate in turn. The test flow rate selection parameters are: 5L / min, 10L / min, 15L / min, 20L / min, 25L / min and 30L / min; 1.2.2) Get the forward flow value, Where: Q 前 The real-time flow rate of the valve under test in the forward direction, in m 3 / s, C is the flow coefficient, the value range is: 0.9-0.99, A 前 is the orifice area of ​​the forward flow nozzle, in m 2 , is the pressure difference before and after the forward flow nozzle, in Pa, collected by the pressure difference sensor 904. is the density of the test liquid, unit: kg / m 3 , 1.2.3) Read the transvalvular pressure difference of the forward flow valve. At the same time, read the transvalvular pressure difference value Δp displayed by the pressure difference sensor 2. 前 , 1.2.4) Obtain the effective valve area, Where: EOA is the effective orifice area, in cm 2 , q vRMS During the positive pressure difference period, Q 前 The root mean square of the unit is ml / s, Δp during the positive pressure difference 前 The average value, in mmHg, is the density of the test liquid, in g / cm 3 ; 2) Install the valve to be tested face down. 3) Reflux test, 3.1) Install the valve to be tested in the reverse direction into the valve fixture, fix the valve fixture in the valve test section, seal the sealing position of the valve test section by stepping on the air pump, and then fill the circulation pipeline with liquid. The valve control during the backflow test is: close valve 4 and valve 5, open valve 6 and valve 7, and prepare for the backflow test. 3.2) Start the test. 3.2.1) Parameter settings, Select the specifications of the valve to be tested and select the test transvalvular pressure difference in turn. The specific parameters are: 40mmHg, 80mmHg, 120mmHg, 160mmHg, 200mmHg; 3.2.2) Read the reverse transvalvular pressure difference of the valve. The transvalvular pressure difference Δp of the valve when the valve is installed in reverse is read by the pressure differential sensor 返 , 3.2.3) Obtaining reflux flow data: The flow rate is calculated using the pressure difference of the reflux nozzle - flow rate calculation formula, as follows: Where: Q 返 is the reflux flow rate, in m 3 / s, A 返 is the orifice area of ​​the return nozzle, in m 2 ; is the pressure difference before and after the reflux nozzle, in Pa, collected by the pressure difference sensor 3: is the density of the test liquid, in kg / m 3 , 4) Complete the test of one valve under test.

[0017] In view of the forward flow and reflux characteristics, the present invention innovatively sets the test channel as a switchable test channel that can adapt to two different orders of magnitude of flow. The forward flow test and the reflux test use pressure differential sensors of different ranges, which reduces the error of the test data. The forward flow nozzle and the reflux nozzle are connected in parallel, and the nozzle switching can also be completed by switching the manual ball valve. The valve clamp also adopts a variety of implementation methods. It is clamped and sealed by an inflatable sealing ring, and the tested valves of different specifications can be quickly replaced to adapt to different test scenarios. The control system can clearly observe the data curve of the transvalvular pressure difference and the system flow. After the curve stabilizes, the test data can be collected. The collected flow and transvalvular pressure difference of the tested valve will be displayed in the data report, and the effective valve orifice area will be automatically calculated by the internal program. The test report will be output after the test is completed. The transvalvular pressure difference value Δp of the valve can be seen in the report. 前 The calculated effective valve area (EOA) data can be used to evaluate the blood flow resistance and flow capacity of the valve, and to assess whether it can meet the physiological needs of the human body; provide a reliable performance basis for valve design optimization and clinical application, and calculate the regurgitant flow rate Q 返 This data can be used to evaluate the "gold standard" parameters of artificial heart valve closing performance and verify the valve's closing integrity and structural reliability.

[0018] The present invention does not require dismantling the entire pipeline to replace the valve to be tested, but only requires replacing the valve to be tested in the valve fixture. At the same time, the present invention adopts parallel connection of the forward flow nozzle and the reverse flow nozzle, and there is no need to replace the nozzle when switching the test. Both forward flow and reverse flow tests can be achieved on a set of test equipment, which effectively improves the test accuracy and work efficiency and reduces the test cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a three-dimensional schematic diagram of the present invention; Figure 2 It is the hydraulic control principle diagram of the present invention; Figure 3 This is a schematic diagram of the forward flow test of the present invention; Figure 4 This is a schematic diagram of the hydraulic control principle during the forward flow test of the present invention; Figure 5 It is a schematic diagram of the reflux test of the present invention; Figure 6 This is a schematic diagram of the hydraulic control principle during the reflux test of the present invention; Figure 7 It is a structural schematic diagram of the backflow nozzle in the present invention; Figure 8 This is a schematic diagram of the assembly structure of the forward flow nozzle test section of the present invention; Figure 9 Schematic diagram of the structure of the forward flow nozzle of the present invention; Figure 10 It is the control principle diagram of the present invention; Figure 11 It is a control flow chart of the present invention; Figure 12 is a stereoscopic diagram of the valve test section of the present invention; Figure 13 is a three-dimensional diagram of a first structural form of the valve clamp of the present invention; Figure 14 1 is a schematic diagram of the valve clamp in the first structural form in the installed state; Figure 15 is a schematic structural diagram of a first structural form of a valve clamp; Figure 16 is a three-dimensional diagram of the second structural form of the valve clamp of the present invention; Figure 17 1 is a schematic diagram of the second structural form of the valve clamp in the installed state; Figure 18 is a schematic structural diagram of a second structural form of the valve clamp; Figure 19 is a three-dimensional diagram of a third structural form of the valve clamp of the present invention; Figure 20 1 is a schematic diagram of the third structural form of the valve clamp in the installed state; Figure 21 is a schematic structural diagram of a third structural form of the valve clamp; Figure 22 is a three-dimensional diagram of a fourth structural form of the valve clamp of the present invention; Figure 23 1 is a schematic diagram of the fourth structural form of the valve clamp in the installed state; Figure 24 is a schematic structural diagram of a fourth structural form of the valve clamp; Figure 25 is the calibration curve diagram of the forward flow nozzle; Figure 26 It is the calibration curve of the return nozzle.

[0021] In the figure, 1 is the rack. 2 is the medium storage tank, 201 is valve 1, 3 is the pump, 4 is the energy storage medium box, 5 is a tee, 6 is the main flow path, 601 is the flow stabilizer, 602 is valve 2, 603 is valve 3, 7 is the throttle branch, 701 is the throttle valve, 8 is the valve test section, 800 is the valve to be tested, 801 is the inflation pump, 81 is the front section, 82 is the back section, 83 is the clamping station, 84 is the inflation seal ring, 85 is the exhaust valve, 9 is a differential pressure sensor, 901 is a differential pressure sensor 1, 902 is a differential pressure sensor 2, 9021 is a solenoid valve 1, 9022 is a solenoid valve 2, 903 is a differential pressure sensor 3, 904 is a differential pressure sensor 4, 10 is the controller, 11 is the return line, 12 is a valve clamp, 121 is T-type clamp, 1211 is silicone sleeve 1, 1212 is lifting ring, 122 is the turntable fixture, 1221 is the second silicone sleeve, 1222 is the turntable bracket, 12221 is the positioning pin, 1223 is the center shaft, 1224 is the receiving hole, 1225 is the positioning hole, 123 is a snap-on fixture, 1231 is a positioning silicone sleeve, 1232 is snap 1, 1233 is the upper box cover, 1234 is the lower box cover, 1235 is the hinge, 1236 is the positioning slot, 124 is the opening and closing clamp, 1241 is the silicone sleeve 3, 1242 is the gasket, 1243 is the buckle 2, 1244 is the clamp box A is the forward flow test circuit, A0 is the forward flow nozzle, A01 is the forward flow nozzle port, A1 is valve four, A2 is valve five, B is the reflux test circuit, B0 is the reflux nozzle, B01 is the reflux nozzle opening, B1 is valve six, and B2 is valve seven. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0023] Among them, the drawings are only used for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting this patent; in order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0024] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "inside", "outside" and the like indicate an orientation or position relationship based on the orientation or position relationship shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0025] In the description of the present invention, unless otherwise expressly specified or limited, when the term "connection" or the like appears to indicate a connection relationship between components, such term should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be internal communication between two components or an interaction between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0026] The following is attached with the instruction manual Figure 1-26 , the present invention is further described.

[0027] like Figure 1-2As shown, an artificial heart valve steady-state flow test device includes a control loop and a circulation loop, the control loop includes a controller 10, and the circulation loop includes: a pump 3, an energy storage medium box 4, a valve test loop, a forward flow test loop A, a reflux test loop B, a throttling branch 7 and a medium storage box 2; the pump 3 is connected to the energy storage medium box 4, the energy storage medium box 4 is connected in parallel to the inlet of the throttling branch 7 and valve two 602, the valve two 602 is connected to the inlet of the valve test loop, the outlet of the valve test loop is connected in parallel with the forward flow test loop A and the reflux test loop B through valve three 603, and the forward flow test loop A and the reflux test loop B are then connected to the outlet of the throttling branch 7 and the medium storage box 2. The entire system is mounted on frame 1. Its operating path is as follows: the low-level outlet of the medium storage tank 2 is connected to the pump 3 via valve 1 201, and then to the energy storage tank 4 via a pipeline. The rear end of the energy storage tank 4 is connected to the main flow 6 (which in turn has a flow stabilizer 601, valve 2 602, and then to the valve test section 8) via a tee 5. One end is connected to the main flow 6, which in turn has a flow stabilizer 601, valve 2 602, and then to the valve test section 8. The other end is connected to the throttling branch 7. The rear end of the valve test section 8 is connected to valve 3 603, which is then connected in parallel to the aforementioned forward flow test loop A and reflux test loop B. The outlets of the forward flow test loop A and reflux test loop B are connected to the return line 11 and the throttling branch 7. A throttling valve 701 is provided on the throttling branch 7 to facilitate adjustment of the system flow during the forward flow test. Regarding the control components, a container for accommodating a pressure differential sensor 9 is provided at the bottom of frame 1. Multiple pressure differential sensors are provided within the container, each of which is connected to a controller 10. The aperture of the forward flow nozzle opening A01 of the forward flow nozzle A0 is larger than the aperture of the return flow nozzle opening B01 of the return flow nozzle B0. In this embodiment, the aperture of the forward flow nozzle opening A01 is φ15-27 mm, and the aperture of the return flow nozzle opening B01 is φ2-8 mm.

[0028] Furthermore, a flow stabilizer 601 is provided in front of the second valve 602 to eliminate fluid flow fluctuations, maintain output stability, and improve system reliability.

[0029] Furthermore, the valve test circuit includes a valve test section 8, a solenoid valve 1 9021, a solenoid valve 2 9022, a pressure differential sensor 2 902 and a pressure differential sensor 1 901, a valve fixture 12, Solenoid valve 1 9021, differential pressure sensor 2 902 and solenoid valve 2 9022 are connected in sequence, and then connected in parallel with differential pressure sensor 1 901 and valve test section 8; Solenoid valve 1 9021, solenoid valve 2 9022, differential pressure sensor 2 902, and differential pressure sensor 1 901 are connected to the controller 10, respectively. The controller includes a PLC control system and an operating program. The PLC precisely controls the speed of pump 3, the opening of the electronically controlled ball valve, and the opening and closing of the solenoid valve, thereby achieving precise control of the entire test process. At the same time, the system collects measurement data from the high-precision differential pressure sensor in real time, forming a closed-loop feedback adjustment mechanism to ensure the stability and reliability of the test conditions. The operation interface integrates two functional modules: forward flow test and backflow test. Before the test begins, the operator needs to select the test type and register test-related information, including operator, test date, and batch data. The operation interface will display the optional valve specifications and corresponding test parameter settings. After confirming the parameters, the system will automatically adjust key parameters such as flow rate and pressure difference to the set values, and judge the system stability by monitoring data fluctuations in real time. After the data stabilizes, click the acquisition button to collect data. After the test is completed, click the save button to output the test report.

[0030] Furthermore, the forward flow test circuit A includes a forward flow nozzle A0, a pressure differential sensor four 904, a valve four A1 and a valve five A2. The valve five A2, the forward flow nozzle A0 and the valve four A1 are connected in sequence. The pressure differential sensor four 904 is connected in parallel with the forward flow nozzle A0. The pressure differential sensor four 904 is connected to the controller 10.

[0031] When performing forward flow testing on artificial heart valves, according to the test requirements given in standard ISO5840-2021, the transvalvular pressure difference of the valve under test is measured in increments of 5L / min within the flow range of 5L / min to 30L / min, and the effective valve orifice area is calculated. Figure 3-4As shown, the specific test is as follows: Initially, all valves are closed. Power on the control system, select the valve to be tested 800, and forwardly install the valve to be tested 800 into the corresponding valve fixture 12. The valve fixture 12 is then installed in the clamping station 83 between the front section 81 and the rear section 82 of the valve test section 8. Step on the air pump 801 to inflate the air sealing ring 84 to complete the sealing of the valve test section 8. Open all valves, inject the test medium into the medium storage box 2, open the exhaust valve 85 to exhaust, and stop injecting liquid when the entire forward flow test loop A is filled with liquid and the liquid level in the medium storage box 2 is higher than the inlet height of the medium storage box 2. Close valve six B1 and valve seven B2 to open the reflux test circuit B, open the operation interface of the controller 10, run the program, register the test related information (operator, test medium, etc.), start the motor, select the forward flow test, and the system will automatically open the solenoid valve one 9021 and the solenoid valve two 9022 at both ends of the pressure differential sensor two 902 to connect the pressure differential sensor two 902 to the system (the pressure difference across the disc in the forward flow is small, so the pressure differential sensor two 902 with a smaller range is used for detection to reduce errors). Continue to select the test point with a flow rate of 5L / min, and the system will automatically adjust the flow rate to 5L / min. The pressure differential sensor 4 904 measures the front and rear pressure differential of the forward flow nozzle A0. The system flow rate can be obtained through the flow-pressure differential calibration curve of the forward flow nozzle A0. Observe the flow fluctuation curve on the operation interface. After the data stabilizes, click the data acquisition button to collect the transvalvular pressure differential of the valve under test 800 measured by the pressure differential sensor 2 902. The calculation formula for the effective valve orifice area is set within the program, and the effective valve orifice area of ​​the valve under test 800 can also be obtained. After completing a test point, continue to select test points with flow rates of 10L / min, 15L / min, 20L / min, 25L / min, and 30L / min until the data collection of all test points is completed, the test report is output, the program is stopped, and the operation interface is closed. If you continue the test, click the stop button and replace the valve under test 800.

[0032] Furthermore, the reflux test circuit B includes a reflux nozzle B0, a pressure differential sensor 903, a valve 6 B1 and a valve 7 B2. The valve 7 B2, the reflux nozzle B0 and the valve 6 B1 are connected in sequence. The pressure differential sensor 903 is connected in parallel with the reflux nozzle B0. The pressure differential sensor 903 is connected to the controller 10.

[0033] When performing a regurgitation test on an artificial heart valve, according to the test requirements given in the standard ISO5840-2021, the leakage flow corresponding to the reverse pressure difference of 5 equidistant valves is measured in the reverse pressure range of 5.2kPa to 26kPa (40mmHg-200mmHg). Figure 5-6As shown, the specific test is as follows: select the valve to be tested 800, reversely install the valve to be tested 800 into the corresponding valve fixture 12, and install the valve fixture 12 in the clamping station 83 between the front section 81 and the rear section 82 of the valve test section 8. Step on the air pump 801 to inflate the air sealing ring 84 to complete the sealing of the valve test section 8. Open all valves, inject test medium into the medium storage tank 2, open the exhaust valve 85, and stop the injection when the entire reflux test loop B is filled with liquid and the liquid level in the medium storage tank 2 is higher than the inlet height of the medium storage tank 2. (If a reflux test is performed after the forward flow test is completed, directly close valve four A1 and valve five A2 at both ends of the forward flow nozzle A0, open valve six B1 and valve seven B2 at both ends of the reflux nozzle B0, and replace the valve 800 under test in reverse.) Close valve four A1 and valve five A2 to prepare for the reflux test, open the operation interface of the controller 10, run the program, register the test related information (operator, test medium, etc.), select the reflux test, and the system will automatically close the solenoid valve one 9021 and the solenoid valve two 9022 at both ends of the pressure differential sensor two 902 to disconnect the pressure differential sensor two 902 from the system (the reflux cross-valve pressure difference is large, so the pressure differential sensor one 901 with a larger range is used for detection to reduce errors; if the pressure differential exceeds the range too much, the pressure differential sensor will be damaged). Select a test point with a transvalvular pressure difference of 40 mmHg, start pump 3, and pressure differential sensor 1 901 can measure the transvalvular pressure difference of the valve 800 under test. If the reading of pressure differential sensor 1 901 deviates from the set test point of 40 mmHg, the system will automatically adjust the working parameters of pump 3 until the transvalvular pressure difference of the valve is adjusted to 40 mmHg. Observe the transvalvular pressure difference fluctuation curve on the operation interface. After the data stabilizes, click the data acquisition button to collect the front and back pressure difference of the reflux nozzle B0 measured by pressure differential sensor 3 903. The system flow rate can be obtained through the nozzle flow-pressure differential calibration curve. After completing one test point, continue to select test points with transvalvular pressure differences of 80 mmHg, 120 mmHg, 160 mmHg, and 200 mmHg until data collection of all test points is completed and the test report is output. Stop the program and close the operation interface. If you continue the test, click the stop button and replace the valve 800 under test. The explanation for the "smaller transvalvular pressure difference in forward flow and larger transvalvular pressure difference in reflux flow" mentioned here is as follows: it is due to objective factors. The heart valve is similar to a one-way valve. In forward flow (that is, when blood flows in the forward direction, the pressure to open the valve is smaller, and in the reverse direction, the valve is closed, but blood will still objectively flow out of the gap at the edge of the valve), this is also the significance of the forward flow and reflux flow tests performed in the present invention.In addition, the main difference in structure between the forward flow nozzle A0 and the reflux nozzle B0 is that the aperture of the forward flow nozzle A01 is larger than the aperture of the reflux nozzle B01. This is to adapt to the blood flow characteristics, that is, since the forward flow rate is large, a larger flow area is required, and the reflux flow rate is small, a smaller flow area is adaptively used.

[0034] like Figure 12 The valve test section 8 includes a front section 81, a rear section 82 and a valve clamp 12. The front section 81 and the rear section 82 are arranged opposite to each other. A clamping station 83 adapted to the valve clamp 12 is formed between the front section 81 and the rear section 82. The valve clamp 12 is clamped in the clamping station 83. The top surfaces of the front section 81 and the rear section 82 are respectively provided with exhaust valves 85. The opposite surfaces of the front section 81 and the rear section 82 are respectively provided with inflation sealing rings 84 corresponding to the valve clamp 12. The inflation sealing ring 84 is connected to the inflation pump 801.

[0035] In this case, four types of valve clamps 12 are preferably used. The valve clamp 12 is a T-shaped clamp 121, such as Figure 13-15 As shown, T-shaped clamp 121 comprises a sheet-like body and a hanging ring 1212. A hole is defined in the center of the sheet-like body for accommodating the valve 800 under test, with a silicone sleeve 1211 positioned between the valve 800 under test and the hole. The bottom of hanging ring 1212 features a rectangular base plate with positioning posts. To use T-shaped clamp 121, the posts are inserted into the positioning holes defined in the front and rear sections 81 and 82. T-shaped clamp 121 is then installed in the clamping station 83. The air pump 801 is then pressed to inflate the inflatable sealing ring 84, which then clamps the valve to seal.

[0036] like Figure 16-18As shown, the valve fixture is a turntable fixture 122, which includes a turntable body and a turntable bracket 1222. The turntable body is provided with a central shaft 1223, which is movably connected to the turntable bracket 1222. The turntable bracket 1222 is fixedly mounted on the top surface of the front section 81 or the rear section 82. The turntable body is provided with a plurality of accommodating holes 1224 arranged on the same circumference. The outer circumference of the valve 800 to be tested is covered with a second silicone sleeve 1221, which is then positioned within the accommodating holes. When using the turntable fixture 122, multiple valves 800 to be tested are placed into the holes on the turntable body, and then the turntable body is installed in the clamping station 83. The characteristic of the turntable fixture 122 is that when testing the same flow direction, it is only necessary to pass the inflatable sealing ring 84 through the air pump 801 (the air pump 801 and the inflatable sealing ring 84 are connected by an air nozzle, and the air can be exhausted by pressing the air nozzle). After exhausting, the turntable body is rotated to allow the next valve to be tested 800 to enter the clamping station 83. After pressing the air pump 801 to expand the inflatable sealing ring 84, the valve fixture is clamped to complete the seal, thereby improving testing efficiency. To achieve the locking feature of the turntable fixture 122, an axially movable positioning pin 12221 is provided on the turntable bracket 1222, and a number of positioning holes 1225 are evenly distributed on the outside of the turntable body around the central rotation axis 1223. The positioning pin 12221 is used to lock the turntable body. It should be noted that the positioning pin 12221 can be manually pulled out and inserted in the axial direction. Of course, the positioning locking structure formed by the positioning hole 1225 and the positioning pin 12221 corresponds to the indexing position of the accommodating hole one by one.

[0037] like Figure 19-21 As shown, the valve clamp is a snap-on clamp 123, which includes a snap-on clamp 1232, an upper box cover 1233, a lower box cover 1234 and a hinge 1235. One side of the upper box cover 1233 and the lower box cover 1234 are respectively fixedly connected to the upper and lower hinge pieces of the hinge 1235, and the other side of the upper box cover 1233 and the lower box cover 1234 are fixedly connected to the snap-on clamp 1232. Semicircular holes for accommodating the valve 800 to be tested are respectively provided between the upper box cover 1233 and the lower box cover 1234, and positioning grooves 1236 are provided on the semicircular holes. The outer circular sleeve of the valve 800 to be tested is provided with a positioning silicone sleeve 1231 adapted to the positioning grooves 1236. When using the snap-on clamp 123, place the valve 800 to be tested into the positioning silicone sleeve 1231, place the positioning silicone sleeve 1231 into the positioning groove 1236, close the snap-on 1232 on the upper box cover 1233 and the lower box cover 1234, and then insert the snap-on clamp 1233 into the clamping station 83.

[0038] like Figure 22-24As shown, the valve clamp is an open-and-close clamp 124, which includes a gasket 1242, a second buckle 1243, and a clamp box 1244. The clamp box 1244 has a left-right opening and closing structure. The center of the clamp box 1244 is provided with a hole for accommodating the valve under test 800. A third silicone sleeve 1241 is placed between the valve under test 800 and the hole. The clamp box 1244 has gasket holes with a diameter larger than the hole, and gaskets 1242 are placed in the gasket holes. When using the open-and-close clamp 124, the valve under test 800 is placed in the third silicone sleeve 1241, the second buckle 1243 is closed, and the open-and-close clamp 124 is then inserted into the clamping station 83.

[0039] Before testing, the four valve clamps 12 are all sealed by pressing the air pump 801 to expand the inflatable sealing ring 84 and then clamping the valve clamp 12. During testing, the direction of the valve 800 to be tested is replaced or the valve can be removed by exhausting the air pump 801 after the test is completed.

[0040] A steady-state flow test method for an artificial heart valve comprises installing the artificial heart valve into a valve fixture, starting the system, and then performing the following steps: 1) Forward flow test, 1.1) Preparation before testing, 1.1.1) Install the valve 800 to be tested into the valve testing section 8. Select the target valve 800 to be tested, assemble it in the valve fixture 12, fix the valve fixture 12 in the valve test section 8, and seal the sealing position of the valve test section 8 by stepping on the air pump 801. 1.1.2) Fill the circulation pipeline with liquid. Open all manual ball valves, start pump 3, and inject test liquid into the circulation pipeline until the pipeline is completely filled. Confirm that the liquid level of the medium storage tank 2 is higher than the inlet end, and the liquid level of the energy storage medium tank 4 is higher than the outlet end. 1.1.3) Valve control: close valve 6 B1 and valve 7 B2 to make the backflow test loop B open circuit and prepare for the forward flow test. 1.2) Start the test. 1.2.1) Parameter setting: Fill in the test-related information on the operation interface, such as the number of the valve 800 to be tested, the test date, etc., select the specifications of the valve 800 to be tested, and select the test flow rate in turn. The specific parameters are: 5L / min, 10L / min, 15L / min, 20L / min, 25L / min and 30L / min. When the flow rate range is 5L / min to 30L / min, measure the transvalvular pressure difference of the forward flow of the valve to be tested in increments of 5L / min.

[0041] 1.2.2) Flow rate parameters: The flow rate is calculated by the pressure difference of the forward flow test nozzle - the flow rate calculation formula, the formula is as follows: Where: Q 前 The real-time flow rate of the valve under test in the forward direction, in m 3 / s, C is the flow coefficient, the value range is: 0.9-0.99, A 前 is the orifice area of ​​the forward flow nozzle, in m 2 , is the pressure difference before and after the forward flow nozzle, in Pa, collected by the pressure difference sensor 904. is the density of the test liquid, unit: kg / m 3 , Forward flow nozzle calibration curve, such as Figure 25 As can be seen from the figure: by fitting the curve with the calibration data points, the pressure difference and flow rate relationship of the forward flow nozzle is obtained, and then the forward flow rate can be obtained by collecting the pressure difference of the forward flow nozzle. 1.2.3) Read the positive transvalvular pressure difference: the transvalvular pressure difference ΔP of the valve 前 Real-time monitoring and collection are carried out through the differential pressure sensor 902. The sensor measurement accuracy meets the latest standard requirements (error range ≤ ±0.26kPa). The minimum measurement accuracy of all other measuring devices should be within ±5% of the full scale reading (for example: the accuracy of the flow meter is ±1.5l / min).

[0042] 1.2.4) Calculation of effective valve orifice area: Based on the relationship between flow rate and pressure difference, the effective valve orifice area of ​​the valve under test 800 is derived using the following formula: Where: EOA is the effective orifice area, in cm 2 , q vRMS During the positive pressure difference period, Q 前 The root mean square of the unit is ml / s, Δp during the positive pressure difference 前 The average value, in mmHg, is the density of the test liquid, in g / cm 3 ; The Δp of the valve during the positive pressure gradient is obtained in the steady-state forward flow test. 前 Average value The core purpose of these two parameters, effective valve area (EOA), is to evaluate the blood flow resistance and flow capacity of the valve, and to assess whether it can meet the physiological needs of the human body; to provide a reliable performance basis for valve design optimization and clinical application.

[0043] 2) Valve replacement operation process: System isolation and pressure relief: Close valve 2 602 and valve 3 603 to cut off the test loop fluid channel to prevent excessive loss of test solution in the pipeline and deflate the inflatable sealing ring 84.

[0044] Fixture removal and replacement: Take out the tested valve fixture 12 and replace it with the target valve (the valve model and assembly direction mark need to be checked).

[0045] Reassemble the valve clamp 12 and seal it by stepping on the air pump 801 to ensure that there is no liquid leakage at the interface of the valve clamp 12.

[0046] Test restart steps: Open valve 2 602 and valve 3 603 to restore circulation. Refill and exhaust according to the pre-test preparation process. After confirming that the liquid levels in the medium storage tank 2 and the energy storage medium tank 4 meet the requirements, start the test procedure.

[0047] 3) Reflux test, 3.1) Install the valve 800 to be tested in the reverse direction into the valve fixture 12, fix the valve fixture 12 into the valve test section 8, seal the sealing position of the valve test section 8 by stepping on the air pump 801, and then fill the circulation pipeline with liquid. Valve and fixture assembly: Select the target valve 800 to be tested and fix it in the valve fixture 12 according to the reverse assembly requirements. Check the air tightness of the fixture sealing position by stepping on the air pump 801. Fill the circulation pipeline: Open all manual ball valves, start pump 3, and inject test liquid into the circulation pipeline until the pipeline is completely filled. Confirm that the liquid level in the medium storage tank 2 is higher than the inlet end and the liquid level in the energy storage medium tank 4 is higher than the outlet end.

[0048] Valve control: Close valve four A1 and valve five A2 to prepare for the backflow test.

[0049] 3.2) Start testing 3.2.1) Parameter Setting: Fill in the test-related information on the operation interface, such as the number of the valve 800 being tested, the test date, etc. Select the specifications of the valve 800 being tested, and select the test transvalvular pressure difference in turn. The specific parameters are: 40mmHg, 80mmHg, 120mmHg, 160mmHg, and 200mmHg.

[0050] 3.2.2) Transvalvular pressure difference parameter: transvalvular pressure difference of valve regurgitation Δp 返The differential pressure sensor 901 is used for real-time monitoring and collection, and the sensor's measurement accuracy meets the latest standard requirements.

[0051] 3.2.3) Flow data collection: The flow rate is calculated by the pressure difference of the return nozzle B01 - the flow rate calculation formula, the formula is as follows: Where: Q 返 is the reflux flow rate, in m 3 / s, A 返 is the orifice area of ​​the return nozzle, in m 2 ; is the pressure difference before and after the reflux nozzle, in Pa, collected by the pressure difference sensor 903: is the density of the test liquid, in kg / m 3 , Through this step, the reverse transvalvular pressure difference Δp of the valve is controlled 返 , obtain the pressure difference before and after the reflux nozzle , and then calculate the reflux flow Q according to the formula in step 3.2.3) 返 , reflux flow Q 返 It is the "gold standard" parameter for evaluating the closing performance of artificial heart valves, and its purpose is to verify the closing integrity and structural reliability of the valve.

[0052] Backflow nozzle calibration curve, such as Figure 26 ,It can be seen from the figure: by fitting the curve with the calibration data points, the pressure difference and flow rate relationship of the reflux nozzle is obtained, and then the reflux flow rate can be obtained by collecting the pressure difference of the reflux nozzle.

[0053] 4) Complete the test of one valve under test.

[0054] To test valves in batches, just repeat the above steps.

[0055] The above-described testing method of the present invention allows for both forward and reverse flow testing using only one set of the present test fixture by switching the test circuit, effectively obtaining the actual performance indicators of a single valve under test. When conducting batch testing, the test fixture of the present invention can be used to quickly replace the valve under test in one operating state, completing testing of a batch of products in one state before switching the test circuit to test another state of the batch.

[0056] It should be noted that the above-described specific embodiments are merely preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that, based on the technical content disclosed in this application, various modifications, equivalent substitutions, and variations may be made to the present invention. However, as long as these modifications do not depart from the spirit of the present invention, they are intended to be within the scope of protection of the present invention. Furthermore, certain terms used in the specification and claims of this application are not intended to be limiting and are provided solely for ease of description.

Claims

1. An artificial heart valve steady-state flow test device, comprising a control loop and a circulation loop, wherein the control loop comprises a controller (10), characterized in that: The circulation loop comprises: a pump (3), an energy storage medium box (4), a valve test loop, a forward flow test loop (A), a backflow test loop (B), a throttling branch (7) and a medium storage box (2); The pump (3) is connected to the energy storage medium box (4), the energy storage medium box (4) is connected in parallel to the inlet of the throttling branch (7) and valve 2 (602), the valve 2 (602) is connected to the inlet of the valve test circuit, the outlet of the valve test circuit is connected in parallel to the forward flow test circuit (A) and the reflux test circuit (B) through valve 3 (603), and the forward flow test circuit (A) and the reflux test circuit (B) are further connected to the outlet of the throttling branch (7) and the medium storage box (2); A flow stabilizer (601) is also provided in front of the second valve (602); The forward flow test circuit (A) includes a forward flow nozzle (A0), a pressure differential sensor four (904), a valve four (A1) and a valve five (A2), wherein the valve five (A2), the forward flow nozzle (A0) and the valve four (A1) are connected in sequence, and the pressure differential sensor four (904) is connected in parallel with the forward flow nozzle (A0); the pressure differential sensor four (904) is connected to the controller (10); The backflow test circuit (B) includes a backflow nozzle (B0), a differential pressure sensor 3 (903), a valve 6 (B1) and a valve 7 (B2), wherein the valve 7 (B2), the backflow nozzle (B0) and the valve 6 (B1) are connected in sequence, and the differential pressure sensor 3 (903) is connected in parallel with the backflow nozzle (B0); the differential pressure sensor 3 (903) is connected to the controller (10); The aperture of the forward flow nozzle opening (A01) of the forward flow nozzle (A0) is larger than the aperture of the reverse flow nozzle opening (B01) of the reverse flow nozzle (B0).

2. The artificial heart valve steady-state flow testing device according to claim 1, characterized in that: The valve test circuit includes a valve test section (8), a solenoid valve 1 (9021), a solenoid valve 2 (9022), a pressure differential sensor 2 (902) and a pressure differential sensor 1 (901), a valve clamp (12), The solenoid valve 1 (9021), the pressure differential sensor 2 (902) and the solenoid valve 2 (9022) are connected in sequence, and then connected in parallel with the pressure differential sensor 1 (901) and the valve test section (8); The solenoid valve 1 (9021), the solenoid valve 2 (9022), the pressure difference sensor 2 (902) and the pressure difference sensor 1 (901) are respectively connected to the controller (10).

3. The artificial heart valve steady-state flow testing device according to claim 2, characterized in that: The valve test section (8) includes a front section (81), a rear section (82) and a valve clamp (12), wherein the front section (81) and the rear section (82) are arranged relative to each other, and a clamping station (83) adapted to the valve clamp (12) is formed between the front section (81) and the rear section (82), and the valve clamp (12) is clamped in the clamping station (83), and the top surfaces of the front section (81) and the rear section (82) are respectively provided with exhaust valves (85), and the opposite surfaces of the front section (81) and the rear section (82) are respectively provided with inflation seals (84) corresponding to the valve clamp (12), and the inflation seals (84) are connected to an inflation pump (801).

4. The artificial heart valve steady-state flow testing device according to claim 3, characterized in that: The valve clamp is a T-shaped clamp (121), which comprises a sheet-like body and a hanging ring (1212). A hole for accommodating the valve to be tested (800) is provided at the center of the sheet-like body, and a silicone sleeve (1211) is provided between the valve to be tested (800) and the hole.

5. The artificial heart valve steady-state flow testing device according to claim 3, characterized in that: The valve clamp is a turntable clamp (122), and the turntable clamp (122) includes a turntable body and a turntable bracket (1222). The turntable body is provided with a central rotating shaft (1223), and the central rotating shaft (1223) is movably connected to the turntable bracket (1222). The turntable bracket (1222) is fixedly arranged on the top surface of the front section (81) or the rear section (82); a plurality of accommodating holes (1224) on the same circumference are arranged on the turntable body, and the outer circle of the valve to be tested (800) is provided with a second silicone sleeve (1221), and the second silicone sleeve (1221) is further arranged in the accommodating holes.

6. The artificial heart valve steady-state flow testing device according to claim 5, characterized in that: An axially movable positioning pin (12221) is provided on the turntable bracket (1222), and a plurality of positioning holes (1225) are evenly distributed on the outer side of the turntable body around the central rotating shaft (1223). The positioning pin (12221) is used to lock the turntable body.

7. The artificial heart valve steady-state flow testing device according to claim 3, characterized in that: The valve clamp is a snap-on clamp (123), which includes a snap-on clamp (1232), an upper box cover (1233), a lower box cover (1234) and a hinge (1235). One side of the upper box cover (1233) and the lower box cover (1234) are respectively fixedly connected to the upper and lower hinge pieces of the hinge (1235). The other side of the upper box cover (1233) and the lower box cover (1234) are fixedly connected to the snap-on clamp (1232). Semicircular holes for accommodating the valve (800) to be tested are respectively provided between the upper box cover (1233) and the lower box cover (1234). Positioning grooves (1236) are provided on the semicircular holes. The outer sleeve of the valve (800) to be tested is provided with a positioning silicone sleeve (1231) adapted to the positioning grooves (1236).

8. The artificial heart valve steady-state flow testing device according to claim 3, characterized in that: The valve clamp is an open-and-close clamp (124), and the open-and-close clamp (124) includes a gasket (1242), a second buckle (1243) and a clamp box (1244). The clamp box (1244) is a left-right opening and closing structure. A hole for accommodating the valve to be tested (800) is provided at the center of the clamp box (1244). A silicone sleeve (1241) is provided between the valve to be tested (800) and the hole. Gasket holes with a diameter larger than the hole are provided on both sides of the clamp box (1244), and the gasket (1242) is provided in the gasket hole.

9. A method for testing an artificial heart valve using a steady-state flow testing device for an artificial heart valve according to claim 1, characterized in that: Place the prosthetic heart valve into the valve fixture, start the system, and then follow these steps: 1) Forward flow test, 1.1) Preparation before testing, 1.1.1) The valve to be tested (800) is installed in the valve fixture (12) in the forward direction, the valve fixture (12) is fixed in the valve test section (8), and the sealing position of the valve test section (8) is sealed by stepping on the air pump (801). 1.1.2) Fill the circulation pipeline with liquid and open all valves. 1.1.3) Valve control, Close valve six (B1) and valve seven (B2) to open the backflow test circuit (B) and prepare for the forward flow test. 1.2) Start the test. 1.2.1) Parameter settings, Select the specifications of the valve (800) to be tested, and select the test flow rate in turn, the test flow rate selection parameters are: 5L / min, 10L / min, 15L / min, 20L / min, 25L / min and 30L / min; 1.2.2) Get the forward flow value, Where: Q 前 The real-time flow rate of the valve under test in the forward direction, in m 3 / s, C is the flow coefficient, the value range is: 0.9-0.99, A 前 is the orifice area of ​​the forward flow nozzle, in m 2 , is the pressure difference before and after the forward flow nozzle, in Pa, collected by the pressure difference sensor 4 (904), is the density of the test liquid, unit: kg / m 3 , 1.2.3) Read the transvalvular pressure difference of the forward flow valve. At the same time, the transvalvular pressure difference value Δp of the valve under test displayed by the pressure difference sensor 2 (902) is read. 前 , 1.2.4) Obtain the effective valve area, Where: EOA is the effective orifice area, in cm 2 , q vRMS During the positive pressure difference period, Q 前 The root mean square of the unit is ml / s, Δp during the positive pressure difference 前 The average value, in mmHg, is the density of the test liquid, in g / cm 3 ; 2) Install the valve to be tested face down. 3) Reflux test, 3.1) The valve to be tested (800) is installed in the valve fixture (12) in reverse, and the valve fixture (12) is fixed in the valve test section (8). The sealing position of the valve test section (8) is sealed by stepping on the air pump (801), and then the circulating pipeline is filled with liquid. The valve control during the backflow test is: close valve 4 (A1) and valve 5 (A2), open valve 6 (B1) and valve 7 (B2), and prepare for the backflow test. 3.2) Start the test. 3.2.1) Parameter settings, Select the specifications of the valve (800) to be tested, and select the test transvalvular pressure difference in turn, with the specific parameters being: 40 mmHg, 80 mmHg, 120 mmHg, 160 mmHg, and 200 mmHg; 3.2.2) Read the reverse transvalvular pressure difference of the valve. The transvalvular pressure difference Δp of the valve when the valve is installed in reverse is read by the pressure difference sensor 1 (901) 返 , 3.2.3) Obtaining reflux flow data: The flow rate is calculated by the pressure difference of the reflux nozzle (B01) - the flow rate calculation formula, which is as follows: Where: Q 返 is the reflux flow rate, in m 3 / s, A 返 is the orifice area of ​​the return nozzle, in m 2 ; is the pressure difference before and after the reflux nozzle, in Pa, collected by pressure difference sensor 3 (903): is the density of the test liquid, in kg / m 3 , 4) Complete the test of one valve under test.

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