A multi-mode parallel valve fatigue life test device

Abstract

The present invention belongs to the field of medical device technology, and specifically relates to a multi-mode parallel valve fatigue life test device, including a flow channel module, a drive module, a compliance module, and a valve installation module. The valve installation module includes a valve installation tube, and one end of the valve installation tube is provided with a plurality of valve installation holes. The flow channel module includes a first flow channel tube and a second flow channel tube. The first flow channel tube connects the valve installation tube and the drive module, and the second flow channel tube is provided with an image acquisition processing module. The image acquisition processing module includes an image collector and an image processor, and collects images at the valve installation holes in the valve installation tube facing the image, and transmits them to the image processor for processing and output. The valve fatigue life test device of the present invention can realize the simultaneous testing of multiple valve parts, can control a single variable, and has more rigorous test results. The instantaneous state of the valve is directly tracked by three-dimensional imaging analysis through image acquisition, which provides a certain theoretical basis for valve test evaluation and optimization.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices, and in particular relates to a multi-mode parallel valve fatigue life testing device. Background Art

[0002] Artificial heart valve replacement technology has been successfully applied in clinical practice and has become a routine operation in cardiac surgery. The lives of millions of heart valve patients have been extended. Artificial heart valves have become a high-tech industry in the world. At present, dozens of artificial heart valve products have entered the market. As an artificial organ, people are most concerned about how long it can work without failure after being implanted in the body, that is, the fatigue life of the artificial heart valve. The US FDA and 150 organizations have clearly stipulated that in vitro simulated fatigue tests must be conducted. IS05840-3:2013 clearly states that the fatigue performance of the support structure of the transcatheter artificial heart valve should be evaluated, and the test shows that it is reasonable to ensure that the support structure withstands at least 400×106 test cycles under critical load modes to maintain its function.

[0003] How the in vitro accelerated fatigue life test is related to the physiological conditions in vivo, that is, whether the in vitro experimental data can reflect the working conditions of the designed artificial heart valve in vivo to a certain extent, is a problem of concern at home and abroad. At the same time, as a high-risk Class III implantable medical device, artificial heart valves have strict requirements on the uniformity of valve performance produced by enterprises. Since the test is irreversibly destructive and costly, the possible failure modes of the valve should be fully identified in the early product development and design. The prior art, such as the patent document with publication number CN103622763A, discloses a multi-mode parallel valve fatigue life test device, which at least includes a body composed of upper and lower flow channels interconnected with each other, an opening is set on one side of the bottom of the body, a linear motor is loaded on one side of the top, and a liquid container is set on the other side of the top that is connected to the body and has an open cover on the top. A damper is provided directly below the linear motor at one end of the lower layer, and a temperature sensor is provided at the other end. The upper layer of the main body also includes a valve holder with a through hole, which is horizontally placed in the flow channel of the upper layer of the main body and arranged below the liquid container; a piston with a rolling diaphragm is connected to the shaft of the linear motor, and the piston is inserted into the main body. The linear motor of the present invention directly applies the load waveform to the test liquid through current control and transmits it to the test valve or other test pieces according to Pascal's law, and filters the high-frequency oscillation signal in the test fluid through the liquid container. The above-mentioned test device cannot test multiple groups of valve parts under the same control variable, and the observation window cannot reflect the instantaneous movement state of the valve, including the opening and closing of the valve. If the leaflet cannot be effectively opened or closed completely, the valve leakage will increase, and even the change in the valve flow field will produce excessive shear stress, which will damage blood cells and activate platelets, directly affecting the performance and durability of the valve and reducing the effectiveness of the test.

[0004] In view of the above technical problems, it is necessary to improve them. Summary of the invention

[0005] Based on the above-mentioned deficiencies in the prior art, the present invention provides a multi-mode parallel valve fatigue life testing device.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0007] A multi-mode parallel valve fatigue life testing device comprises a flow channel module, a driving module, a compliance module and a valve installation module, wherein the valve installation module comprises a valve installation cylinder, one end of which is provided with a plurality of valve installation holes, the flow channel module comprises a first flow channel tube and a second flow channel tube, the first flow channel tube connects the valve installation cylinder and the driving module, the compliance module is connected to the wall of the second flow channel tube and is connected to the inside of the second flow channel tube; one end of the valve installation cylinder provided with a plurality of valve installation holes is connected to one end of the second flow channel tube, the other end of the second flow channel tube is connected to an end cover facing the valve installation cylinder, a mounting groove is provided in the center of the end cover, the mounting groove is used to connect an image acquisition and processing module, the image acquisition and processing module comprises an image collector and an image processor; the image collector is plugged into the mounting groove, collects images at the valve installation holes in the valve installation cylinder facing the image, and transmits the images to the image processor for processing and output.

[0008] As a preferred embodiment, one end of the first flow channel is connected to the valve mounting tube wall and communicated with the valve mounting tube, the other end of the first flow channel is communicated with the driving module, and a mounting frame is plugged into the port at the other end of the mounting tube wall, and the mounting frame is used to place a light source and / or an image collector.

[0009] As a preferred solution, the number of the plurality of valve mounting holes is 8, the valve mounting holes are arranged circumferentially, and the valve mounting holes are connected to electromagnetic valves to control the opening and closing of the valve mounting holes.

[0010] As a preferred solution, a lens holder is provided in the end cover mounting groove, and the lens holder is used for contacting and fitting the image collector.

[0011] As a preferred solution, the image collector includes at least two high-speed cameras arranged in parallel, the image processor includes an image acquisition card, a camera controller, and a computer, and the image collector cooperates with the image processor to perform three-dimensional imaging analysis of image acquisition.

[0012] As a preferred solution, the image collector further includes any one or more combinations of a light source, a black and white camera, a wide-angle camera, and a telephoto camera arranged in parallel with the high-speed camera.

[0013] As a preferred solution, a light source and / or an image collector is provided in the second flow channel tube.

[0014] As a preferred solution, a fluid viscosity compensator is provided in the first flow channel tube and / or the second flow channel tube.

[0015] As a preferred solution, a first pressure sensor is provided in the first flow channel tube, and a second pressure sensor is provided in the second flow channel tube.

[0016] As a preferred solution, any one or more combinations of a damper, a temperature controller, and a flow sensor are provided in the first flow channel tube and / or the second flow channel tube.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) Multiple valve mounting holes are installed in the valve mounting frame, which can realize the simultaneous testing of multiple valve components, and the test group and the control group are placed in the same test environment for analysis, strictly controlling a single variable, and the test results are more rigorous.

[0019] 2) The instantaneous state of the valve is directly tracked by three-dimensional imaging analysis using at least two high-speed cameras, which provides a feasible method for extracting the instantaneous motion state of the valve and also provides a certain theoretical basis for valve evaluation and optimization.

[0020] 3) Set up fluid viscosity compensators, dampers, temperature controllers and other devices to enhance the simulation of in vivo physiological conditions and enhance the effectiveness of measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a structural schematic diagram of a valve fatigue life test device according to a first embodiment of the present invention;

[0022] Figure 2 1 is a schematic diagram of the top view of the structure of the valve fatigue life test device according to the first embodiment of the present invention;

[0023] Figure 3 It is a structural schematic diagram of a valve mounting tube of a valve fatigue life testing device according to Embodiment 1 of the present invention;

[0024] Figure 4 It is a schematic cross-sectional structural diagram of a valve mounting cylinder of a valve fatigue life testing device according to Embodiment 1 of the present invention;

[0025] Figure 5 It is a structural schematic diagram of an image acquisition and processing module of a valve fatigue life test device according to the first embodiment of the present invention;

[0026] Figure 6 It is a structural schematic diagram of an image collector of a valve fatigue life test device according to the first embodiment of the present invention;

[0027] Figure 7 This is a comparison diagram of the test results of the valve fatigue life test device according to the first embodiment of the present invention;

[0028] Among them: 11. first flow channel tube; 12. second flow channel tube; 2. linear motor; 21. piston; 22. motor protection cover; 3. liquid chamber; 31. exhaust valve; 4. valve mounting tube; 41. valve mounting hole; 42. solenoid valve; 5. end cover; 51. mounting slot; 52. lens bracket; 6. image acquisition device; 61. image acquisition card; 62. camera controller; 63. computer; 64. auxiliary light source; 65. high-speed camera; 7. temperature controller; 8. damper; 91. first pressure sensor; 92. second pressure sensor; 10. fluid viscosity compensator; 11. flow sensor. DETAILED DESCRIPTION

[0029] In order to more clearly illustrate the embodiments of the present invention, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only embodiments of the present invention, and for those of ordinary skill in the art, other accompanying drawings and other implementation methods can be obtained based on these drawings without creative work.

[0030] Embodiment 1:

[0031] like Figure 1-7 As shown, the valve fatigue life test device of this embodiment is used for in vitro accelerated fatigue life test of artificial heart valves, including a flow channel module, a drive module, a compliance module, and a valve installation module. The valve installation module includes a valve installation tube 4, and one end of the valve installation tube 4 is provided with a plurality of valve installation holes 41. The flow channel module includes a first flow channel tube 11 and a second flow channel tube 12. The first flow channel tube 11 connects the valve installation tube 4 and the drive module. The compliance module is connected to the wall of the second flow channel tube 12 and is connected to the second flow channel tube 12. 2; one end of the valve mounting tube 4 is provided with a plurality of valve mounting holes 41, which is connected to one end of the second flow channel tube 12; the other end of the second flow channel tube 12 is connected to an end cover 5 facing the valve mounting tube 4; a mounting groove 51 is provided in the center of the end cover 5; the mounting groove 51 is used to connect the image acquisition processing module, and the image acquisition processing module includes an image collector 6 and an image processor; the image collector 6 is plugged into the mounting groove 51, collects images at the valve mounting holes 41 in the valve mounting tube 4 facing the image, and transmits them to the image processor for processing and output.

[0032] Specifically, the driving module is composed of a linear motor 2 and a piston 21. The linear motor 2 is installed at one end of the first flow channel tube 11, and the piston 21 extends into the first flow channel tube 11. A motor protection sleeve 22 is installed at the other end of the linear motor 2. One end of the first flow channel is connected to the wall of the valve mounting tube 4 and connected to the valve mounting tube 4. One end of the linear motor 2 is connected to the piston 21 through a screw rod. The piston 21 is driven to reciprocate by an electrode to simulate the movement of a ventricular pump. The constant pressure of the load is directly loaded on the test fluid in the flow channel module by controlling the current. The load received by the test fluid is transmitted to the valve assembly to be tested. The linear motor 2 is connected to a corresponding control end such as a computer 63. The power source is controlled by an electrode controller using a left ventricular drive control algorithm obtained by simulation to adjust the movement of the linear motor 2, so that the artificial heart valve fatigue test system The system is more consistent with the physiological state of the human blood circulation system; the first flow channel tube 11 is bent at 90 degrees, leaving the port space at the other end of the valve mounting tube 4 wall empty, and the left space can facilitate the disassembly and installation of the valve mounting tube 4. Preferably, the left space is also opposite to the valve mounting hole 41, and the port plug-in mounting frame of the valve mounting tube 4 at this empty end can set up a light source and / or an image collector 6. The light source is preferably an LED cold light source to reduce interference with experimental detection. At the same time, the image collector 6 attached here can assist the image collector 6 at the end cover 5 to establish a more complete three-dimensional imaging and collect more valve movement state data; the compliance module is composed of a liquid storage chamber 3, and the top of the liquid storage chamber 3 has an exhaust valve 31. The liquid storage chamber 3 is connected to the wall of the second flow channel tube 12 and is connected to the second flow channel tube 12.

[0033] A plurality of valve mounting holes 41 are evenly arranged in the valve mounting tube 4. Preferably, the number of the valve mounting holes 41 is 8, and the 8 valve mounting holes 41 are arranged circumferentially. The detachably connected ring is on a bearing and can be rotated to adjust the position. An electromagnetic valve 42 is installed at the bottom or side of the valve mounting hole 41 and connected to a corresponding controller. The valve mounting hole 41 can be opened and closed according to experimental needs. Under normal circumstances, 1-8 valves can be measured at the same time, and different types of valve mounting holes 41 can be selected according to test needs to meet test needs. Since the image collector 6 at the end cover 5 is facing the valve mounting hole 41, the valve mounting tube 4 is made of a material with good light-gathering properties, such as applying a layer of reflective material on the wall of the valve mounting tube 4. Similarly, the wall of the second flow channel tube 12 can provide good lighting conditions for the image collector 6.

[0034] The end cap 5 is made of an opaque material. A layer of reflective material can be applied to one side of the end cap 5 facing the second flow channel tube 12 to form a good light-gathering environment in cooperation with the second flow channel tube 12. A lens holder 52 is provided in the mounting groove 51 of the end cap 5. The lens holder 52 is used to contact and fit the lens of the image collector 6. While installing and positioning, the position of the image collector 6 is not easy to shake. At the same time, the lens holder 52 can be selected to cooperate with different optical lenses, such as lenses with different convexities. In cooperation with the lens of the image collector 6, image acquisition functions such as magnification, focusing, and microscopic observation can be realized.

[0035] The image acquisition device 6 uses at least two high-speed cameras 65 arranged in parallel, and the image processor includes an image acquisition device card 61, a camera controller 62, and a computer 63. The image acquisition device 6 cooperates with the image processor to perform three-dimensional imaging analysis of image acquisition. A single high-speed camera 65 can track the movement state of the valve and capture the instantaneous opening and closing state of the valve. The two high-speed cameras 65 arranged in parallel are connected to the image acquisition device card 61, the camera controller 62, and the computer 63. The software program can realize three-dimensional imaging, and the accurate information such as the opening angle and opening area of ​​the valve can be calculated. At the same time, the three-dimensional movement model of the valve under test can be simulated. The movement state and defects can be carefully and comprehensively observed through the three-dimensional model in the computer 63, and simulation modifications can be performed in real time, which is greatly beneficial to the testing and development of the valve. Preferably, the image collector 6 can also be set with any one or more combinations of light sources, black and white cameras, wide-angle cameras, and telephoto cameras arranged in parallel with the high-speed camera 65, wherein the light source adopts LED cold light source or more advanced attosecond light source, which can greatly improve the image acquisition quality, and the black and white camera can improve the image acquisition quality in low light conditions by cooperating with the high-speed camera; the fusion algorithm in the wide-angle camera and the telephoto camera can provide smooth, high-quality optical zoom, and provide high-detail, low-noise image acquisition. Preferably, the end of the second flow channel tube 12 close to the valve mounting tube 4 can be plugged into the auxiliary light source 64 and / or the image collector 6 through the tube wall, and the auxiliary light source 64 can improve the lighting conditions in the second flow channel tube 12, and the newly added image collector 6 can cooperate with the image collector 6 at the end of the auxiliary end cover 5 to better collect image information for establishing a three-dimensional model.

[0036] Furthermore, any one or more combinations of a fluid viscosity compensator 10, a pressure sensor, a damper 8, a temperature controller 7, and a flow sensor 11 are provided in the first flow channel tube 11 and / or the second flow channel tube 12, so as to better control the conditions of the test device simulating the human body environment. For example, in this embodiment, a temperature controller 7, a damper 8, and a first pressure sensor 91 are provided in the first flow channel tube 11, and a second pressure sensor 92, a fluid annual compensator, and a flow sensor 11 are provided in the second flow channel tube 12; wherein, the fluid viscosity compensator 10 can monitor the viscosity of the simulated blood fluid circulating in the device in real time, and add reagent compensation in time according to the deviation from the viscosity baseline, so as to provide a stable viscosity level for the entire fatigue test process. , minimizing the deviation as much as possible; the first pressure sensor 91 and the second pressure sensor 92 are distributed on both sides of the valve mounting hole 41, and can test the systolic and diastolic pressures of the simulated aorta on both sides of the artificial heart valve; the temperature controller 7 is mainly composed of a temperature sensor and a heater. The temperature control system is connected to the computer 63. The temperature sensor detects the current liquid temperature and controls the real-time adjustment of the signal output to the heater so that the temperature of the simulated blood liquid in the test device is maintained within the range of 37°C±0.5°C during the test process, meeting the requirements of the normal body physiological environment; the damping device is used to simulate the intravascular resistance effect, is connected to the computer 63, and controls the resistance through an intelligent algorithm; the flow sensor can monitor the flow during the test.

[0037] When operating, first, select a suitable valve mounting hole 41 according to the test needs, fix the artificial heart valve to be tested and the standard control valve in the valve mounting hole 41, and open the electromagnetic valve 42 corresponding to the channel with the valve to be tested. Finally, install the valve mounting tube 4 into the flow channel module. Connect the external water pump, open the exhaust valve 31 of the liquid chamber 3, inject the simulated human test fluid from the opening of the device, and fill the entire test device with the test fluid to remove the bubbles in the closed cavity. Connect the temperature controller 7, the damper 8, the first pressure sensor 91, the second pressure sensor 92, the fluid viscosity compensator 10 and the flow sensor 11 to the computer 63, debug the system and set the parameters. Start the temperature control, wait for the fluid temperature in the device to be heated to within the range of 37℃±0.5℃, adjust the gas-liquid ratio in the liquid chamber 3, and close the exhaust valve 31; start the linear motor 2, observe the pressure curve, adjust the damper 8, the exhaust valve 31 and the motor drive output, and start the test after stabilization.

[0038] During the test, the linear motor 2 controls the piston 21 to directly apply the load to the simulated human test fluid in the flow channel. When the motor reciprocates, the test fluid transfers the load to the valve to be tested, causing the valve to open; another section of the simulated human test fluid in the valve component directly passes a constant pressure. When the linear motor 2 drives the piston 21 to move outward, the pressure is greater than the pressure at the end of the linear motor 2, and the valve to be tested is closed. When the linear motor 2 drives the piston 21 to move inward, the pressure is less than the pressure at the end of the linear motor 2, and the valve to be tested is opened.

[0039] The high-speed camera 65 arranged in parallel at the end cover 5 tracks the movement state of the valve throughout the whole process, captures the instantaneous opening and closing state of the valve, cooperates with the image processor to perform three-dimensional imaging, model building, and information processing, and obtains accurate information such as the opening angle and opening area of ​​the valve. At the same time, the simulated body fluid viscosity compensation device monitors the viscosity of the circulating simulated human test fluid in real time, and solvent can be added in time for adjustment when fluctuations occur.

[0040] In the same production batch, four aortic valves with a size of 23 mm were selected for testing, and the simulated human test fluid was prepared based on the viscosity of adult male blood. The viscosity values ​​of the test fluid in the device during the first 48 hours of the test were collected and compared with the viscosity data of the general fatigue test device. The experimental data are as follows: Figure 7 As shown, it can be found that the viscosity of the simulated blood fluid in the test process of the present invention is more stable, so that the test data of valve fatigue is more realistic and consistent with statistical significance.

[0041] The image processor computer 63, in combination with the image processing software, selects an image with the largest valve opening angle of each aortic valve during the cardiac cycle as a reference, sets a three-coordinate system, inputs the key size parameters of the valve, determines the valve opening boundary and the area to be calculated, and obtains specific values ​​such as the opening angle and the open area according to the control algorithm of the computer 63. The following Table 1 is the data obtained from the opening area and the opening angle during different aortic valve fatigue processes in the implementation case of the present invention:

[0042] Aortic valve 1# 2# 3# 4# <![CDATA[Opening area / cm 2 > 1.55 1.31 1.45 1.37 Opening angle / ° 69 72 74 81

[0043] Table 1

[0044] It can be seen that under the same test environment, the opening area and opening angle of the valve in the same batch are significantly different. These data have a great driving force for the analysis of valve structure design, material selection, and production process parameters.

[0045] The valve fatigue life test device of the present embodiment can install 1-8 valves at the same time for synchronous testing, and can place the test group and the control group under the same test environment for analysis, strictly control a single variable, and make the test result more rigorous, providing a convenient and effective test system for testing multiple artificial valves at the same time and analyzing the performance differences between valves; the parallel high-speed cameras 65 are used to directly track the instantaneous state of the valve, providing a feasible method for extracting the valve movement, and also providing a certain theoretical basis for valve evaluation and optimization; at the same time, a fluid viscosity compensator 10 is provided to monitor the viscosity of the simulated blood fluid in the system in real time, and compensate the reagent in time, so as to maintain a stable viscosity level during the entire test process and reduce the impact of viscosity imbalance on the test results.

[0046] It should be noted that the above description is only a detailed description of the preferred embodiments and principles of the present invention. For ordinary technicians in this field, there will be changes in the specific implementation methods based on the ideas provided by the present invention, and these changes should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-mode parallel valve fatigue life test device, comprising a flow channel module, a drive module, a compliance module, and a valve installation module, characterized in that: The valve installation module includes a valve installation tube, one end of which is provided with a plurality of valve installation holes, the flow channel module includes a first flow channel tube and a second flow channel tube, the first flow channel tube is connected with the valve installation tube and the driving module, the compliance module is connected to the wall of the second flow channel tube and is connected to the second flow channel tube; one end of the valve installation tube provided with a plurality of valve installation holes is connected with one end of the second flow channel tube, the other end of the second flow channel tube is connected with an end cover facing the valve installation tube, the center of the end cover is provided with a mounting groove, the mounting groove is used to connect the image acquisition processing module, the image acquisition processing module includes an image collector and an image processor; the image collector is plugged into the mounting groove, collects images at the valve installation holes in the valve installation tube facing the image, and transmits the images to the image processor for processing and output; The valve mounting holes are arranged circumferentially, and the valve mounting holes are connected to electromagnetic valves to control the opening and closing of the valve mounting holes; A lens bracket is provided in the end cover mounting groove, and the lens bracket is used to contact and fit the image collector; An auxiliary light source and an image collector are inserted into the tube wall of the second flow channel tube near one end of the valve mounting tube, and the auxiliary light source improves the lighting conditions inside the second flow channel tube, and the image collector on the tube wall of the second flow channel tube assists in cooperating with the image collector on the end cover to collect and establish corresponding three-dimensional model image information.

2. A multi-mode parallel valve fatigue life test device as claimed in claim 1, characterized in that: One end of the first flow channel is connected to the valve mounting tube wall and communicated with the valve mounting tube, the other end of the first flow channel is communicated with the driving module, and a mounting frame is plugged into the port at the other end of the mounting tube wall, and the mounting frame is used to place a light source and / or an image collector.

3. A multi-mode parallel valve fatigue life test device as claimed in claim 1, characterized in that: The image collector includes at least two high-speed cameras arranged in parallel, the image processor includes an image acquisition card, a camera controller, and a computer, and the image collector cooperates with the image processor to perform three-dimensional imaging analysis of image acquisition.

4. A multi-mode parallel valve fatigue life test device as claimed in claim 3, characterized in that: The image collector also includes any one or more combinations of a light source, a black and white camera, a wide-angle camera, and a telephoto camera arranged in parallel with the high-speed camera.

5. A multi-mode parallel valve fatigue life test device as claimed in claim 1, characterized in that: A light source and / or an image collector is arranged in the second flow channel tube.

6. A multi-mode parallel valve fatigue life test device as claimed in claim 1, characterized in that: A fluid viscosity compensator is provided in the first flow channel tube and / or the second flow channel tube.

7. A multi-mode parallel valve fatigue life test device as claimed in claim 6, characterized in that: A first pressure sensor is disposed in the first flow channel tube, and a second pressure sensor is disposed in the second flow channel tube.

8. A multi-mode parallel valve fatigue life test device as claimed in claim 7, characterized in that: Any one or more combinations of a damper, a temperature controller, and a flow sensor are arranged in the first flow channel tube and / or the second flow channel tube.

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