Non-vascular stent fatigue testing apparatus

Abstract

This invention belongs to the field of non-vascular stent fatigue testing technology, specifically a non-vascular stent fatigue testing device. It includes: an environmental chamber containing a simulated liquid; a support frame fixedly connected to the bottom of the environmental chamber; a first telescopic rod fixedly connected to the bottom of the support frame; a first plate fixedly connected below the first telescopic rod; a first rod fixedly connected below the first plate; and a second plate fixedly connected below the first rod. The non-vascular stent fatigue testing device also includes: a composite testing unit. By setting up the composite testing unit, this invention can perform multi-axis composite load testing on non-vascular stents, thereby more realistically simulating the load conditions experienced by non-vascular stents in vivo, thus improving the realism of the simulation.

Description

Technical Field

[0001] This invention belongs to the field of non-vascular stent fatigue testing technology, specifically a non-vascular stent fatigue testing device. Background Technology

[0002] Non-vascular stents are tubular medical devices implanted in lumens or cavities outside the human vascular system to support narrowed or collapsed areas and keep cavities open; non-vascular stents require fatigue testing.

[0003] When performing fatigue testing on non-vascular stents, an airbag clamp system is typically used. The airbag clamp mainly consists of two parts: a flexible airbag and a rigid outer sleeve. The flexible airbag is connected to a pressure controller. During testing, the controller periodically inflates and deflates the airbag. When inflated, the air pressure causes the flexible airbag to expand radially, squeezing the non-vascular stent outward. However, because the rigid sleeve blocks the non-vascular stent, the flexible airbag cannot expand outward, and its pressure is converted into a uniform, 360-degree inward compressive force on the non-vascular stent. When deflated, the flexible airbag contracts, relieving the pressure on the non-vascular stent. This process is repeated to achieve the test.

[0004] However, the above tests are too simplistic in terms of load on non-vascular stents. In vivo, non-vascular stents are subjected to multi-axial composite loads, so they cannot reproduce the complex biomechanical environment in vivo, resulting in simulation distortion.

[0005] In view of this, the present invention provides a non-vascular stent fatigue testing device to solve the above-mentioned technical problems. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies and enable multi-axis composite load testing of non-vascular stents, thereby more realistically simulating the load conditions of non-vascular stents in vivo, this invention provides a non-vascular stent fatigue testing device.

[0007] The technical solution adopted by this invention to solve its technical problem is: a non-vascular stent fatigue testing device, comprising: an environmental chamber containing a simulated liquid; a support frame fixedly connected to the bottom of the environmental chamber; a first telescopic rod fixedly connected to the bottom of the upper part of the support frame; a first plate fixedly connected below the first telescopic rod; a first rod fixedly connected below the first plate; and a second plate fixedly connected below the first rod; the non-vascular stent fatigue testing device further comprises: a composite testing unit, which is capable of performing multi-axis composite load tests on non-vascular stents, thereby more realistically simulating the load conditions of non-vascular stents in vivo and improving the realism of the simulation;

[0008] The simulated solution is designed to mimic human bodily fluids and can be a saline solution at 37°C.

[0009] Preferably, the composite testing unit includes: an outer tube, with several tube frames provided on the top of the second plate, and an outer tube fixedly connected to the top of each tube frame; a motion plate, with a motion plate provided on the top of the second plate, and an airbag frame fixedly connected to the top of the motion plate corresponding to each outer tube; a first motor fixedly connected inside each airbag frame, and a rotating disk rotatably connected to the part of each airbag frame facing the outer tube, the rotating disk being fixedly connected to the output shaft of the first motor; a support rod fixedly connected to the center of the rotating disk, the support rod extending into the outer tube; a tubular airbag fixedly connected to the side of the rotating disk, the tubular airbag wrapping the support rod; several through holes are opened on the rotating disk, the through holes being distributed in a ring on the rotating disk, each through hole being covered by a tubular airbag, and a ventilation chamber opened inside each airbag frame, the ventilation chamber being able to communicate with multiple through holes, the ventilation chamber being connected to an external air pump through an air pipe.

[0010] Preferably, each outer tube is fixedly connected to an annular electromagnet at one end relative to the airbag frame. An annular cavity is formed inside the tube wall of each outer tube near the annular electromagnet. An annular block is slidably connected inside the annular cavity. A spring is fixedly connected between the annular block and the end of the annular cavity. An annular airbag is fixedly embedded in the inner wall of the outer tube. The annular airbag is located at the end of the outer tube near the annular electromagnet and communicates with the interior of the annular cavity. A connecting rod is fixedly connected to the annular block. The end of the connecting rod passes through the outer tube and the annular electromagnet and protrudes from the outer tube. A compression block is fixedly connected to the end of the connecting rod. The annular electromagnet can attract the compression block.

[0011] A non-vascular stent is fitted over a tubular balloon. Then, a telescopic rod moves a second plate down into an environmental chamber for simulation testing. During the test, air is intermittently pumped into the tubular balloon via an air pump and ventilation chamber, causing the balloon to expand and contract intermittently. Due to the constraint of the outer tube, the pressure is converted into a uniform, 360-degree inward compressive force on the non-vascular stent, thus achieving the test—this is the existing testing method. However, in vivo, the non-vascular stent bears multi-axial composite loads. For example, esophageal / intestinal stents also experience torsional loads, and airway stents experience bending due to neck rotation. Therefore, an annular electromagnet can be energized to attract a compression block, causing the annular block to compress the annular cavity. This compresses the first spring, inflates the annular balloon, and compresses the non-vascular stent, fixing one end of the stent. Then, a motor drives a rotating disk and the tubular balloon to rotate slightly back and forth. The rotation amplitude can be set. Because the stent is fitted over the tubular balloon, it also twists, simulating the stent's torsion within the body.

[0012] Preferably, each of the sleeve holders is slidably engaged with the second plate;

[0013] The cannula frame slides and snaps into the No. 2 plate. This design allows the cannula frame to be detached, facilitating the installation of non-vascular stents. In addition, different sizes of outer cannulas can be replaced to meet different testing needs.

[0014] Preferably, a cavity is formed at the top of the second plate and below the corresponding moving plate. One end of the first cavity is fixedly connected to an electromagnet, and the other end of the first cavity is slidably connected to a control block. A second spring is fixedly connected between the first electromagnet and the control block. The first electromagnet can attract the control block. A square block is fixedly connected to the bottom of the moving plate, and the square block is connected to the control block.

[0015] Preferably, a lead screw is rotatably connected inside the control block, the lead screw is driven by a motor, and the square block is threadedly connected to the lead screw.

[0016] Preferably, an elastic membrane is fixedly connected between the square block and the control block, and between the control block and the side wall of the first cavity;

[0017] Within the body, the esophageal / intestinal stent also exhibits linear motion along its length, i.e., peristalsis along the digestive tract. Therefore, as described above, when one end of the fixed stent is energized and de-energized, the control block moves closer to or further away from the first electromagnet in coordination with the second spring. Because the square block is fixed to the motion plate, the tubular balloon stretches and contracts along its length, driving the non-vascular stent to move linearly along its length, simulating the linear motion of the non-vascular stent along its length, such as peristalsis in the digestive tract. In addition, when the non-vascular stent is fixed at one end, the lead screw rotates, causing the square block to move back and forth left and right, causing the tubular balloon to bend left and right, and thus the non-vascular stent to bend left and right, simulating left and right bending motion. The amplitude of the above movements can be controlled, and the elastic membrane can be made of rubber. The elastic membrane prevents the simulated liquid from entering the device.

[0018] Preferably, a second electromagnet is fixedly connected to one end of the support rod near the airbag frame, and a sliding ring is slidably connected to the other end of the support rod away from the airbag frame. A third spring is fixedly connected between the second electromagnet and the sliding ring, and the second electromagnet can attract the sliding ring. Several contact rods are rotatably connected around the sliding ring, and torsion springs are provided at the connection points. A third electromagnet is fixedly provided around the sliding ring at the corresponding positions of the contact rods, and the third electromagnet can attract the contact rods so that the contact rods are parallel to the support rod. At this time, the torsion springs are charged.

[0019] In the body, non-vascular stents also experience localized point loads, such as the instantaneous high pressure when a food bolus or feces passes through the esophagus / intestine. Therefore, when the tubular balloon inflates, the third electromagnet is de-energized. Under the reset of the torsion spring, the contact rod expands and contacts the inner wall of the tubular balloon from the inside, and then contacts the non-vascular stent. At this time, the second electromagnet is energized again, attracting the sliding ring. The third spring is compressed, causing the contact rod to move and contact the stent. This simulates the instantaneous high pressure when a food bolus or feces passes through the esophagus / intestine, making the simulation results closer to reality.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. The non-vascular stent fatigue testing device of the present invention, by setting up a composite testing unit, can perform multi-axis composite load testing on non-vascular stents, thereby more realistically simulating the load conditions of non-vascular stents in vivo; thus improving the realism of the simulation.

[0022] 2. The non-vascular stent fatigue testing device of the present invention involves energizing a ring electromagnet to attract a compression block, causing the ring block to compress the ring cavity, compressing a spring, inflating the ring airbag, and compressing the non-vascular stent to fix one end of the stent. Subsequently, a motor drives a rotating disk and a tubular airbag to rotate slightly back and forth. The rotation amplitude can be set. Since the stent is fitted on the tubular airbag, the stent also twists, simulating the torsion of the stent in the body. Attached Figure Description

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] Figure 1 This is a perspective view of the present invention;

[0025] Figure 2 This is a partial three-dimensional representation of the present invention. Figure 1 ;

[0026] Figure 3 This is a partial three-dimensional representation of the present invention. Figure 2 ;

[0027] Figure 4 This is a partial three-dimensional representation of the present invention. Figure 3 ;

[0028] Figure 5 yes Figure 4 Side sectional view;

[0029] Figure 6 This is a cross-sectional view of the outer tube, support rod, airbag frame, and tubular airbag of the present invention;

[0030] Figure 7 yes Figure 6 A magnified view of part A;

[0031] Figure 8 This is a cross-sectional view of the outer sleeve of the present invention;

[0032] Figure 9 yes Figure 8 A magnified view of section B;

[0033] In the diagram: 1. Environmental chamber; 11. Support frame; 12. Telescopic rod No. 1; 13. Plate No. 1; 14. Rod No. 1; 15. Plate No. 2; 2. Composite test unit; 21. Outer tube; 22. Tube frame; 23. Motion plate; 24. Airbag frame; 25. Motor No. 1; 26. Rotating disk; 27. Support rod; 28. Tubular airbag; 29. ​​Through hole; 3. Ventilation chamber; 4. Ring electromagnet; 41. Ring cavity; 42. Ring block; 43. Spring No. 1; 44. Ring airbag; 45. Connecting rod; 46. Compression block; 5. Cavity No. 1; 51. Electromagnet No. 1; 52. Control block; 53. Spring No. 2; 54. Square block; 55. Lead screw; 6. Elastic membrane; 7. Electromagnet No. 2; 71. Sliding ring; 72. Spring No. 3; 73. Contact rod; 74. Electromagnet No. 3. Detailed Implementation

[0034] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0035] like Figure 1 As shown, the non-vascular stent fatigue testing device of the present invention includes: an environmental chamber 1 containing a simulated liquid; a support frame 11 is fixedly connected to the bottom of the environmental chamber 1, a first telescopic rod 12 is fixedly connected to the bottom of the upper part of the support frame 11, a first plate 13 is fixedly connected below the first telescopic rod 12, a first rod 14 is fixedly connected below the first plate 13, and a second plate 15 is fixedly connected below the first rod 14; the non-vascular stent fatigue testing device also includes: a composite testing unit 2, which is arranged above the second plate 15 and between the first plate 13 and the second plate 15. The composite testing unit 2 can perform multi-axis composite load testing on the non-vascular stent, thereby more realistically simulating the load conditions of the non-vascular stent in the body;

[0036] During fatigue testing of non-vascular stents, an airbag clamp system is typically used. This system consists of two main parts: a flexible airbag and a rigid outer sleeve 21. The flexible airbag is connected to a pressure controller. During testing, the controller periodically inflates and deflates the airbag. Inflation causes the flexible airbag to expand radially, compressing the non-vascular stent outwards. However, because the rigid sleeve blocks the outward expansion of the non-vascular stent, the flexible airbag cannot expand further, and its pressure is converted into a uniform, 360-degree inward compressive force on the non-vascular stent. Deflating the airbag releases the pressure on the non-vascular stent, and this process is repeated to achieve the test. However, the above test results in a single load on the non-vascular stent. In vivo, the non-vascular stent experiences multi-axial composite loads, making it impossible to reproduce the complex biomechanical environment in vivo, leading to simulation distortion. Therefore, a composite testing unit 2 is introduced. This unit can perform multi-axial composite load testing on the non-vascular stent, thus more realistically simulating the load conditions experienced by the non-vascular stent in vivo and improving the realism of the simulation.

[0037] The simulated solution is designed to mimic human bodily fluids and can be a saline solution at 37°C.

[0038] As one specific embodiment of the present invention, such as Figure 1 , Figure 2 , Figure 3 , Figure 6 As shown, the composite test unit 2 includes: an outer tube 21, with several tube frames 22 mounted on the top of the second plate 15, each tube frame 22 having an outer tube 21 fixedly connected to its top; a motion plate 23, with a motion plate 23 mounted on the top of the second plate 15, and an airbag frame 24 fixedly connected to the top of the motion plate 23 corresponding to each outer tube 21; a first motor 25 fixedly connected inside each airbag frame 24, and a rotating disk 26 rotatably connected to the part of each airbag frame 24 facing the outer tube 21, the rotating disk 26 and the first motor 25... The output shaft is fixedly connected; a support rod 27 is fixedly connected to the center of the rotating disk 26, and the support rod 27 extends into the outer sleeve 21; a tubular airbag 28 is fixedly connected to the side of the rotating disk 26, and the tubular airbag 28 wraps the support rod 27; several through holes 29 are opened on the rotating disk 26, and the through holes 29 are distributed in a ring on the rotating disk 26. Each through hole 29 is covered by the tubular airbag 28. Each airbag frame 24 has a ventilation chamber 3 inside, and the ventilation chamber 3 can communicate with multiple through holes 29. The ventilation chamber 3 is connected to an external air pump through an air pipe.

[0039] like Figure 8 , Figure 9As shown, each outer tube 21 is fixedly connected to one end of the airbag frame 24 with an annular electromagnet 4. An annular cavity 41 is formed in the inner wall of each outer tube 21 near the annular electromagnet 4. An annular block 42 is slidably connected in the annular cavity 41. A spring 43 is fixedly connected between the annular block 42 and the end of the annular cavity 41. An annular airbag 44 is fixedly embedded in the inner wall of the outer tube 21. The annular airbag 44 is located at the end of the outer tube 21 near the annular electromagnet 4 and communicates with the inside of the annular cavity 41. A connecting rod 45 is fixedly connected to the annular block 42. The end of the connecting rod 45 passes through the outer tube 21 and the annular electromagnet 4 and protrudes from the outer tube 21. A compression block 46 is fixedly connected to the end of the connecting rod 45. The annular electromagnet 4 can attract the compression block 46.

[0040] During operation, the non-vascular stent is fitted over the tubular balloon 28. Then, the first telescopic rod 12 moves the second plate 15 down into the environmental chamber 1 for simulation testing. During the test, air is intermittently pumped into the tubular balloon 28 through the air pump and ventilation chamber 3, causing the balloon to intermittently expand and contract. Due to the constraint of the outer tube 21, the pressure is converted into a uniform, 360-degree inward compressive force on the non-vascular stent, thus achieving the test—this is the existing testing method. However, in vivo, the non-vascular stent bears multiaxial composite loads. For example, esophageal / intestinal stents also experience torsional loads, and airway stents experience bending due to neck rotation. Therefore, at this time, the annular electromagnet 4 can be energized to attract the compression block 46, causing the annular block 42 to compress the annular cavity 41. The first spring 43 is compressed, and the annular airbag 44 expands, compressing the non-vascular stent and fixing one end of the stent. Subsequently, the first motor 25 drives the rotating disk 26 and the tubular airbag 28 to rotate back and forth slightly. The rotation amplitude can be set. Since the stent is fitted on the tubular airbag 28, the stent also twists, simulating the twisting of the stent in the body. To ensure better clamping between the annular airbag 44 and the tubular airbag 28, the surface of the annular airbag 44 facing the inner wall of the outer sleeve 21 can be hardened. The area of ​​the balloon 28 corresponding to the annular balloon 44 also undergoes surface hardening treatment. Surface hardening treatment can be achieved by spraying a hard coating material, such as polyurethane coating or epoxy resin coating, or by adding reinforcing ribs, supporting frames, or plastic / metal frames to the inner or outer walls of the annular balloon 44 and the tubular balloon 28. Because the pressure at the mating point of the annular balloon 44 and the tubular balloon 28 is greater than in other areas, and because of the hardening treatment, the annular balloon 44 and the tubular balloon 28 can achieve a clamping effect. Furthermore, the movement of the non-vascular stent within the human body is within a certain range and is gentle; therefore, during simulation testing, the simulated movement does not need to be excessive. The large range of motion reduces excessive pulling on the stent, ensuring that the annular balloon 44 and the tubular balloon 28 can hold the non-vascular stent. This application uses the annular balloon 44 and the tubular balloon 28 to hold the stent directly inside the outer tube 21, which saves more space compared to clamping with telescopic cylinders and metal grippers, and can achieve clamping inside the outer tube 21. Since the stent is stuck in the human body channel, clamping it inside the outer tube 21 also simulates the situation where the stent is stuck in the human body channel. In addition, the relatively soft cooperation between the annular balloon 44 and the tubular balloon 28 simulates the soft tissue of the human body.

[0041] As one specific embodiment of the present invention, such as Figure 3 As shown, each sleeve bracket 22 is slidably engaged with plate number 15;

[0042] During operation, the cannula frame 22 slides and engages with the second plate 15. This design allows the cannula frame 22 to be detached, facilitating the installation of non-vascular stents. In addition, different sizes of outer cannulas 21 can be replaced to meet different testing needs.

[0043] As one specific embodiment of the present invention, such as Figure 2 , Figure 4 , Figure 5 As shown, a cavity 5 is opened at the top of the second plate 15 and below the corresponding moving plate 23. One end of the first cavity 5 is fixedly connected to an electromagnet 51, and the other end of the first cavity 5 is slidably connected to a control block 52. A second spring 53 is fixedly connected between the first electromagnet 51 and the control block 52. The first electromagnet 51 can attract the control block 52. A square block 54 is fixedly connected to the bottom of the moving plate 23. The square block 54 is connected to the control block 52.

[0044] like Figure 5 As shown, a lead screw 55 is rotatably connected inside the control block 52. The lead screw 55 is driven by a motor, and the square block 54 is threadedly connected to the lead screw 55.

[0045] like Figure 4 As shown, an elastic membrane 6 is fixed between the square block 54 and the control block 52, and between the control block 52 and the side wall of the first cavity 5.

[0046] During operation, the esophageal / intestinal stent also exhibits linear motion along its length within the body, i.e., peristalsis along the digestive tract. Therefore, as described above, when one end of the fixed stent is energized, the first electromagnet 51 is switched on and off. With the cooperation of the second spring 53, the control block 52 moves closer to and further away from the first electromagnet 51. Since the square block 54 is fixed to the motion plate 23, the tubular balloon 28 stretches and contracts along its length, causing the non-vascular stent to move linearly along its length, simulating the linear motion of the non-vascular stent along its length, such as peristalsis of the digestive tract. In addition, when one end of the fixed non-vascular stent is fixed, the lead screw 55 rotates, causing the square block 54 to move back and forth left and right, causing the tubular balloon 28 to bend left and right, and thus the non-vascular stent to bend left and right, simulating left and right bending motion. The amplitude of the above movements can be controlled. The elastic membrane 6 can be made of rubber. The elastic membrane 6 is set to prevent the simulated liquid from entering the device. To reduce the influence of the first electromagnet 51 on the outside world, electromagnetic shielding treatment can be applied to the first cavity 5, such as by setting a Faraday cage on the inner wall of the first cavity 5.

[0047] As one specific embodiment of the present invention, such as Figure 6 , Figure 7As shown, a second electromagnet 7 is fixedly connected to one end of the support rod 27 near the airbag frame 24, and a sliding ring 71 is slidably connected to the other end of the support rod 27 away from the airbag frame 24. A third spring 72 is fixedly connected between the second electromagnet 7 and the sliding ring 71. The second electromagnet 7 can attract the sliding ring 71. Several contact rods 73 are rotatably connected around the sliding ring 71, and torsion springs are provided at the connection points. A third electromagnet 74 is fixedly provided around the sliding ring 71 at the corresponding positions of the contact rods 73. The third electromagnet 74 can attract the contact rods 73 so that the contact rods 73 are parallel to the support rod 27. At this time, the torsion springs are charged.

[0048] During operation, within the body, non-vascular stents experience localized point loads, such as the instantaneous high pressure experienced when a food bolus or feces passes through the esophagus / intestine. Therefore, when the tubular airbag 28 expands, electromagnet 74 is de-energized. Under the reset of the torsion spring, contact rod 73 expands, contacting the inner wall of the tubular airbag 28 from the inside, and then contacting the non-vascular stent. At this point, electromagnet 7 is energized again, attracting sliding ring 71, compressing spring 72, and causing contact rod 73 to move and contact the stent, simulating the instantaneous high pressure experienced when a food bolus or feces passes through the esophagus / intestine, making the simulation results closer to reality. Additionally, a metal mesh can be placed inside the tubular airbag 28, which, while increasing the strength of the tubular airbag 28, also reduces the influence of electromagnets 74 and 7 on the external environment.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention without departing from the spirit and scope of the present invention. Any modifications or equivalent substitutions should be covered within the protection scope of the claims of the present invention.

Claims

1. A non-vascular stent fatigue testing device, comprising: An environmental chamber (1) containing a simulated liquid; The environmental chamber (1) is fixedly connected to a support frame (11) at the bottom. A telescopic rod (12) is fixedly connected to the bottom of the support frame (11). A plate (13) is fixedly connected to the bottom of the telescopic rod (12). A rod (14) is fixedly connected to the bottom of the plate (13). A plate (15) is fixedly connected to the bottom of the rod (14). The non-vascular stent fatigue testing device is characterized in that it further includes: Composite test unit (2), a composite test unit (2) is provided above the second plate (15) and between the first plate (13) and the second plate (15). The composite test unit (2) can perform multi-axis composite load test on non-vascular stents, thereby more realistically simulating the load situation of non-vascular stents in the body. The composite test unit (2) includes: The outer sleeve (21) is provided with several sleeve brackets (22) on the top of the second plate (15), and the top of each sleeve bracket (22) is fixedly connected to the outer sleeve (21); A motion plate (23) is provided on the top of the second plate (15). An airbag frame (24) is fixedly connected to the top of the motion plate (23) and to the corresponding part of each outer tube (21). A first motor (25) is fixedly connected inside each airbag frame (24). A rotating disk (26) is rotatably connected to the part of each airbag frame (24) facing the outer tube (21). The rotating disk (26) is fixedly connected to the output shaft of the first motor (25). A support rod (27) is fixedly connected to the center of the rotating disk (26). The support rod (27) extends... The outer sleeve (21) is inserted into the interior; a tubular airbag (28) is fixedly connected to the side of the rotating disk (26), and the tubular airbag (28) wraps the support rod (27); a number of through holes (29) are opened on the rotating disk (26), the through holes (29) are distributed in a ring on the rotating disk (26), each of the through holes (29) is covered by the tubular airbag (28), each of the airbag frames (24) is provided with a ventilation chamber (3), the ventilation chamber (3) can communicate with multiple through holes (29), and the ventilation chamber (3) is connected to an external air pump through an air pipe; Each outer tube (21) is fixedly connected to one end of the airbag frame (24) with a ring electromagnet (4). An annular cavity (41) is formed inside the tube wall of each outer tube (21) near the annular electromagnet (4). An annular block (42) is slidably connected inside the annular cavity (41). A spring (43) is fixedly connected between the annular block (42) and the end of the annular cavity (41). An annular airbag (44) is fixedly embedded in the inner wall of the outer tube (21). The annular airbag (44) is located at the end of the outer tube (21) near the annular electromagnet (4). The annular airbag (44) communicates with the interior of the annular cavity (41); a connecting rod (45) is fixedly connected to the annular block (42), the end of the connecting rod (45) passes through the outer sleeve (21) and the annular electromagnet (4) and protrudes from the outer sleeve (21), and a squeezing block (46) is fixedly connected to the end of the connecting rod (45), and the annular electromagnet (4) can attract the squeezing block (46); the annular airbag (44) is surface hardened on the side facing the inner wall of the outer sleeve (21), and the tubular airbag (28) is surface hardened on the part corresponding to the annular airbag (44).

2. The non-vascular stent fatigue testing device according to claim 1, characterized in that: Each of the aforementioned sleeve holders (22) is slidably engaged with plate number two (15).

3. The non-vascular stent fatigue testing device according to claim 2, characterized in that: A cavity (5) is opened at the top of the second plate (15) and below the corresponding moving plate (23). One end of the first cavity (5) is fixedly connected to an electromagnet (51), and the other end of the first cavity (5) is slidably connected to a control block (52). A second spring (53) is fixedly connected between the first electromagnet (51) and the control block (52). The first electromagnet (51) can attract the control block (52). A square block (54) is fixedly connected to the bottom of the moving plate (23), and the square block (54) is connected to the control block (52).

4. The non-vascular stent fatigue testing device according to claim 3, characterized in that: The control block (52) is internally connected to a lead screw (55), which is driven by a motor. The square block (54) is threadedly connected to the lead screw (55).

5. The non-vascular stent fatigue testing device according to claim 4, characterized in that: An elastic membrane (6) is fixed between the square block (54) and the control block (52), and between the control block (52) and the side wall of the first cavity (5).

6. The non-vascular stent fatigue testing device according to claim 5, characterized in that: The support rod (27) is fixedly connected to a second electromagnet (7) at one end near the airbag frame (24), and a sliding ring (71) is slidably connected to the other end of the support rod (27) away from the airbag frame (24). A third spring (72) is fixedly connected between the second electromagnet (7) and the sliding ring (71). The second electromagnet (7) can attract the sliding ring (71). Several contact rods (73) are rotatably connected around the sliding ring (71), and torsion springs are provided at the connection points. A third electromagnet (74) is fixedly provided around the sliding ring (71) at the corresponding positions of the contact rods (73). The third electromagnet (74) can attract the contact rods (73) so that the contact rods (73) are parallel to the support rod (27). At this time, the torsion springs are charged.

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