Artificial knee joint wear tester

Abstract

The present application discloses an artificial knee joint wear tester, which comprises: a workbench, a second sensor and a swing mechanism; the workbench is provided with four guide pillars and a horizontal top plate; the guide pillars are arranged in a rectangular shape; the horizontal top plate is fixed to the top of the guide pillars; a cam is installed on the horizontal top plate; the cam is connected to the first motor; the cam is connected to the transmission shaft, the transmission shaft is connected to the spring, and the spring is on the connecting plate; the connecting plate is provided with a first sensor, and the connecting plate is connected to the middle plate through a telescopic column; the middle plate is movably connected to the four guide pillars; the middle plate is provided with a first sensor; the middle plate is connected to the left fixed plate and the right fixed plate; the second motor is installed on the left fixed plate; the second motor is connected to the swing plate; the swing plate is movably connected to the right fixed plate; the second clamp is provided on the swing plate; a pulley is provided on the horizontal top plate; the middle plate is connected to the counterweight block through a steel wire rope; the steel wire rope passes around the pulley; and a second sensor is installed above the bottom plate to drive the second sensor to swing. The present application can obtain more comprehensive wear test data.

Description

Technical Field

[0001] The present application relates to the technical field of medical equipment testing, and in particular to an artificial knee joint wear testing machine. Background Art

[0002] With the advancement of technology, implanting artificial frames into the human body to replace bone joints to help patients gain the ability to move freely is now a common technology in the medical field. After the artificial prosthesis is implanted in the human body, it will produce relative movement with the human body's own bones and tissues during service. In this process, if the artificial frame is worn, the small particles produced will be retained in the human body and cause health hazards. Therefore, wear tests are required after the artificial prosthesis is manufactured. The wear test of artificial knee joints in the prior art mainly includes two parts: comprehensive wear test and joint simulation test. Among them, the joint simulation test is mainly carried out in a sliding contact manner on various types of disc-type friction and wear testing machines. The problem with this technical solution is: In addition, the human knee joint movement mode is a complex multi-degree-of-freedom movement mode with flexion, rolling, sliding, lateral displacement and axial rotation. Conventional disc-type friction and wear testing machines are not sufficient to test its friction and wear performance. In addition, the prior art is to test a single sample to be tested, so it is impossible to eliminate the detection interference caused by external sudden factors. Therefore, how to develop a new type of artificial knee joint wear testing machine to overcome the above problems is a direction that technicians in this field need to study. Summary of the invention

[0003] The present application provides an artificial knee joint wear testing machine that can avoid interference from external sudden factors, while enabling artificial knee joint samples to achieve various movement modes close to those of natural knee joints, thereby obtaining more comprehensive wear test data.

[0004] The technical solutions adopted are as follows:

[0005] A wear tester for artificial knee joints, comprising: a workbench; the upper end surface of the workbench is provided with four guide pillars, the four guide pillars are of equal length, extend in the vertical direction and are arranged in a rectangular shape; the top ends of the four guide pillars are respectively connected to a horizontal top plate; a cam is installed on the horizontal top plate; the cam is connected to a first motor; the first motor is used to drive the cam to rotate; the cam is connected to the upper end of the transmission shaft, and is used to drive the transmission shaft to reciprocate in the vertical direction; the lower end of the transmission shaft is connected to the upper end of the spring, and the lower end of the spring is against the upper end surface of the connecting plate; the lower end surface of the connecting plate is provided with a telescopic column, and the connecting plate is connected to the middle plate through the telescopic column; the four corners of the middle plate are respectively movably connected to the four guide pillars; the upper end surface of the middle plate is provided with a first sensor, the first sensor is provided with a first placement groove, the first placement groove Used to place comparison samples; the first sensor is used to sense the pressure value of the comparison sample; the middle plate is connected to the left fixed plate and the right fixed plate respectively by bolts; the left fixed plate is equipped with a second motor; the second motor is connected to the swing plate, used to drive the swing plate to reciprocate in the horizontal direction; the swing plate is movably connected to the right fixed plate; a pulley block is provided on the horizontal top plate; the middle plate is connected to one end of the steel wire rope, and the other end of the steel wire rope passes through the pulley block and is connected to the counterweight block; a positioning seat and a swing mechanism are also installed on the workbench; the positioning seat is located below the middle plate, and a second placement slot is provided on the positioning seat, and the second placement slot is used to place the sample to be tested; a second sensor is installed below the positioning seat, and the second sensor is used to sense the pressure value of the sample to be tested; the swing mechanism is connected to the positioning seat, and is used to drive the positioning seat to swing.

[0006] By adopting this technical solution: the cam moves the transmission shaft downward during the rotation process, and the transmission shaft transmits the pressure to the connecting plate and the telescopic column through the spring. The telescopic column is compressed in this process, and the lower side of the connecting plate presses the comparison sample. At the same time, the middle plate moves downward synchronously, driving the swing plate to move downward synchronously, so that the lower side of the swing plate presses the sample to be tested synchronously. In this way, the comparison sample and the sample to be tested receive the same pressure value synchronously to achieve the effect of data comparison, thereby avoiding the interference of external sudden factors on the sample data. In the above process, the second motor is set to achieve the horizontal fine adjustment of the position of the swing plate, which helps to align the center of the swing plate with the sample to be tested and press down, and optimize the comparison data obtained. By setting the swing mechanism to achieve the left and right swing of the sample to be tested during the detection process, the wear test of the sample is closer to the various movement modes of the natural knee joint, so as to obtain more comprehensive wear test data. After the friction test is completed, the middle plate is pulled back to the initial position by operating the counterweight block.

[0007] Preferably, in the above-mentioned artificial knee joint wear testing machine: the swing mechanism includes a third motor, a disc and a rocker; the disc is coaxially mounted on the motor shaft of the third motor; the edge of the disc is movably connected to one end of the rocker, and the other end of the rocker is movably connected to the positioning seat.

[0008] By adopting this technical solution: when the third motor is driven, it drives the disc coaxially mounted on the motor shaft to rotate, and one end of the rocker rotates synchronously with the rotation of the disc. Since the length of the rocker is fixed, the positioning seat performs a reciprocating left and right swinging action under the transmission of the rocker.

[0009] More preferably, in the above-mentioned artificial knee joint wear testing machine: the swing mechanism also includes a guide rail and a chassis; the positioning seat is movably mounted on the chassis; and the chassis is snap-fitted and mounted on the guide rail.

[0010] By adopting this technical solution: the chassis is moved on the guide rail to fine-tune the relative position between the disc and the positioning seat, thereby indirectly adjusting the left and right swing amplitude of the positioning seat under the transmission of the rocker.

[0011] It is further preferred that the artificial knee joint wear testing machine further comprises an outer frame, wherein the outer frame is located outside the positioning frame, the positioning seat and the swing mechanism.

[0012] By adopting this technical solution, an outer frame is provided to realize external protection for the guide column, the positioning seat and the swing mechanism.

[0013] It is further preferred that, in the above-mentioned artificial knee joint wear testing machine: the bottom of the workbench is provided with universal wheels and liftable feet.

[0014] By adopting this technical solution: universal wheels are set to achieve rolling movement of the artificial knee wear tester. Liftable feet are set to lift the entire workbench after the artificial knee wear tester moves to the specified position, so that the universal wheels leave the ground, ensuring that the workbench is stable and motionless during the test.

[0015] Compared with the prior art, the present application has a simple structure and is easy to implement, and can enable artificial knee joint samples to imitate various movements of natural human knee joints during wear tests, thereby obtaining more comprehensive wear test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a three-dimensional view of Example 1, in which the steel wire rope and the sample to be tested are omitted;

[0017] Figure 2 for Figure 1 A schematic diagram of the structure of the second motor and the swing plate;

[0018] Figure 3 for Figure 1 Structural diagram of the middle swing mechanism;

[0019] Figure 4 for Figure 1 A side view schematic diagram of

[0020] Figure 5 for Figure 1 The main view schematic diagram is shown in FIG. , and the sample to be tested is added to this figure.

[0021] The corresponding relationship between the reference numerals and component names is as follows:

[0022] 1. Workbench; 2. Guide column; 3. Horizontal top plate; 4. Cam; 5. First motor; 6. Transmission shaft; 7. Spring; 8. Connecting plate; 9. Telescopic column; 10. Middle plate; 11. First sensor; 12. Left fixed plate; 13. Right fixed plate; 14. Second motor; 15. Swing plate; 16. Pulley; 17. Counterweight; 18. Positioning seat; 19. Second sensor; 20. Third motor; 21. Disc; 22. Rocker; 23. Guide rail; 24. Chassis; 25. Outer frame; 26. Universal wheel; 27. Liftable feet; 28. Comparison sample; 29. ​​Sample to be tested. DETAILED DESCRIPTION

[0023] like Figure 1-5 Shown is Example 1 of the present application:

[0024] An artificial knee joint wear testing machine comprises: a workbench 1; a universal wheel 26 and a liftable foot 27 are arranged at the bottom of the workbench 1.

[0025] The upper end surface of the workbench 1 is provided with four guide pillars 2, and the four guide pillars 2 are of equal length, extend in the vertical direction and are arranged in a rectangular shape; the top ends of the four guide pillars 2 are respectively connected to a horizontal top plate 3; a cam 4 is installed on the horizontal top plate 3; the cam 4 is connected to a first motor 5; the first motor 5 is used to drive the cam 4 to rotate; the cam 4 is connected to the upper end of the transmission shaft 6, and is used to drive the transmission shaft 6 to reciprocate in the vertical direction; the lower end of the transmission shaft 6 is connected to the upper end of the spring 7, and the lower end of the spring 7 is pressed against the upper end surface of the connecting plate 8; the lower end surface of the connecting plate 8 is provided with a telescopic column 9, and the connecting plate 8 is connected to the middle plate 10 through the telescopic column 9; the four corners of the middle plate 10 are respectively movably connected to the four guide pillars 2; the upper end surface of the middle plate 10 is provided with a first sensor 11, and the first sensor 11 is provided with a first placement groove, and the first placement groove is used to place the comparison sample 28; the first sensor 11 is used to sense The pressure value of the sample 28 should be compared; the middle plate 10 is connected to the left fixed plate 12 and the right fixed plate 13 by bolts respectively; a second motor 14 is installed on the left fixed plate 12; the second motor 14 is connected to the swing plate 15, which is used to drive the swing plate 15 to reciprocate in the horizontal direction; the swing plate 15 is movably connected to the right fixed plate 13; a pulley group 16 is provided on the horizontal top plate 3; the middle plate 10 is connected to one end of the wire rope, and the other end of the wire rope passes through the pulley group 16 and is connected to the counterweight 17; a positioning seat 18 and a swing mechanism are also installed on the workbench 1; the positioning seat 18 is located below the middle plate 10, and a second placement groove is provided on the positioning seat 18, and the second placement groove is used to place the sample 29 to be tested; a second sensor 19 is installed below the positioning seat 18, and the second sensor 19 is used to sense the pressure value of the sample 29 to be tested; the swing mechanism is connected to the positioning seat 18, and is used to drive the positioning seat 18 to swing.

[0026] Specifically, the swing mechanism includes a third motor 20, a disc 21, a rocker 22, a guide rail 23 and a chassis 24; the positioning seat 18 is movably mounted on the chassis 24; the chassis 24 is mounted on the guide rail 23 by snapping. The disc 21 is coaxially mounted on the motor shaft of the third motor 20; the edge of the disc 21 is movably connected to one end of the rocker 22, and the other end of the rocker 22 is movably connected to the positioning seat 18. It also includes an outer frame 25, which is located outside the guide column 2, the positioning seat 18 and the swing mechanism.

[0027] In this example: the first sensor 11 and the second sensor 19 are both weighing sensors NS-TH.

[0028] In practice, the working process is as follows:

[0029] First, the comparison sample 28 is installed on the first placement slot, and the sample to be tested 29 is installed on the second placement slot. Then, the second motor 14 is started, and the second motor 14 drives the swing plate 15 to move in the horizontal direction, so that the pre-stress point is aligned with the center of the sample to be tested 29. Then, the first motor 5 is started, and the first motor 5 drives the cam 4 to rotate. During the rotation, the cam 4 pushes the transmission shaft 6 to move downward. The transmission shaft 6 transmits the pressure to the connecting plate 8 through the spring 7, and the spring 7 is compressed. At the same time, the telescopic column 9 is compressed in this process, so that the plate spacing between the connecting plate 8 and the middle plate 10 becomes smaller. At the same time, the lower side of the connecting plate 8 presses the comparison sample 28, and at the same time, the middle plate 10 is forced to move downward, and the middle plate 10 drives the swing plate 15 to move downward synchronously, so that the swing plate 15 presses the sample to be tested 29, so that the sample to be tested 29 is synchronously subjected to the same pressure value as the comparison sample 28. At this time, the first sensor 11 and the second sensor 19 synchronously output the pressure value readings of the sample to be tested 29 and the comparison sample 28 to achieve the effect of data comparison, thereby avoiding the interference of external sudden factors on the sample data. During the above experiment, the third motor 20 in the swing mechanism is started, and the mounting seat is driven to swing left and right through the rocker 22, so that the wear test of the sample is closer to the various movement modes of the natural knee joint, so as to obtain more comprehensive wear test data. After the friction test is completed, the middle plate 10 is stretched back to the initial position by operating the counterweight block 17.

[0030] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An artificial knee joint wear testing machine, characterized in that: include: Workbench; The upper end surface of the workbench is provided with four guide pillars, which are of equal length, extend in the vertical direction and are arranged in a rectangular shape; the top ends of the four guide pillars are respectively connected to a horizontal top plate; A cam is installed on the horizontal top plate; the cam is connected to the first motor; the first motor is used to drive the cam to rotate; the cam is connected to the upper end of the transmission shaft and is used to drive the transmission shaft to reciprocate in the vertical direction; the lower end of the transmission shaft is connected to the upper end of the spring, and the lower end of the spring is pressed against the upper end surface of the connecting plate; a telescopic column is provided on the lower end surface of the connecting plate, and the connecting plate is connected to the middle plate through the telescopic column; The four corners of the middle plate are movably connected to the four guide pillars respectively; the upper end surface of the middle plate is provided with a first sensor, and the first sensor is provided with a first placement groove, and the first placement groove is used to place the comparison sample; the first sensor is used to sense the pressure value of the comparison sample; the middle plate is respectively connected to the left fixed plate and the right fixed plate by bolts; the left fixed plate is installed with a second motor; the second motor is connected to the swing plate and is used to drive the swing plate to reciprocate in the horizontal direction; the swing plate is movably connected to the right fixed plate; a pulley block is provided on the horizontal top plate; the middle plate is connected to one end of the wire rope, and the other end of the wire rope passes through the pulley block and is connected to the counterweight block; The workbench is also equipped with a positioning seat and a swing mechanism; the positioning seat is located below the middle plate, and a second placement slot is provided on the positioning seat, and the second placement slot is used to place the sample to be tested; a second sensor is installed below the positioning seat, and the second sensor is used to sense the pressure value of the sample to be tested; the swing mechanism is connected to the positioning seat and is used to drive the positioning seat to swing; The swing mechanism comprises a third motor, a disc and a rocker; the disc is coaxially mounted on the motor shaft of the third motor; the edge of the disc is movably connected to one end of the rocker, and the other end of the rocker is movably connected to the positioning seat; The swing mechanism also includes a guide rail and a chassis; the positioning seat is movably installed on the chassis; and the chassis is embedded and installed on the guide rail.

2. The artificial knee joint wear testing machine according to claim 1, characterized in that: It also includes an outer frame, which is located outside the guide column, the positioning seat and the swing mechanism.

3. The artificial knee joint wear testing machine as claimed in claim 2, characterized in that: The bottom of the workbench is provided with universal wheels and liftable feet.

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