CN112294504A

CN112294504A - Shoulder joint prosthesis performance test platform

Info

Publication number: CN112294504A
Application number: CN201910690908.2A
Authority: CN
Inventors: 余红薇
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-07-29
Filing date: 2019-07-29
Publication date: 2021-02-02

Abstract

The invention provides a shoulder joint prosthesis performance test platform, which comprises: the platform can effectively evaluate the basic performance of the shoulder joint prosthesis, can test the rotation angle of the shoulder joint prosthesis in each direction, can test the friction characteristic of the shoulder joint prosthesis, has powerful functions, has certain guiding significance for the material selection and the structural design of the shoulder joint prosthesis, and fills the gap of the performance evaluation of the shoulder joint prosthesis.

Description

Shoulder joint prosthesis performance test platform

Technical Field

The invention relates to the field of medical instruments, in particular to a shoulder joint prosthesis performance test platform.

Background

The shoulder joint is the most flexible ball-and-socket joint with the largest range of motion of the human body, the ball part is composed of skin bones with spherical proximal ends, the socket part is composed of joints with concave shoulder and foot bones, and the shoulder joint, the shoulder and foot bones, the clavicle and the skin bones form the shoulder joint, which is one of the most important friction pair joints of the upper limbs of the human body. Can do the exercises of anteflexion, retroflexion, adduction, abduction, internal rotation, external rotation, circumgyration and the like.

The artificial shoulder joint is used for transduction and effectively reconstructing the function of the diseased joint, so that the life quality of a patient is improved, and the functions of relieving pain, stabilizing the joint, correcting deformity and the like are achieved. After the artificial shoulder joint is implanted into a body, a new biological friction pair is formed, the artificial shoulder joint is in a complex human body operation environment and simultaneously bears the comprehensive effects of tension, pressure, torsion, interfacial shear force, fatigue, abrasion and corrosion, and the implant is inevitably abraded or even fails after long-time use. The types of the artificial shoulder joint prostheses appearing on the market are diversified, but an experimental platform for evaluating and testing the performance of the artificial shoulder joint prostheses is blank, and the recent and future failure problems of the artificial shoulder joints cannot be predicted and effectively evaluated. Therefore, the development of a performance test platform capable of truly simulating the motion mechanism of the human shoulder joint has important and profound significance for clinical use of different types of shoulder joint prosthesis materials and structural forms.

Disclosure of Invention

In order to solve the technical problem, the invention provides a shoulder joint prosthesis performance test platform.

The invention is realized by the following technical scheme:

a shoulder prosthesis performance testing platform, comprising: the device comprises a test platform, a humerus head fixing platform, an air pump, a complete machine support, a parallel rotating platform, a glenoid fixing platform, a pressure sensor, a simulation cabin, a PLC and a PC upper computer.

Further, the humerus head fixing platform, the air pump and the whole machine support are fixed on the test platform, the parallel rotating platform is fixed on the whole machine support, the glenoid fixing platform is fixed on the moving platform of the parallel rotating platform, the simulation bin is located at the upper end of the humerus head fixing platform, the pressure sensor is arranged on the artificial shoulder joint prosthesis to be tested, and the PLC and the PC upper computer are located on the test platform.

Further, the humerus head fixing platform comprises a platform support, an air cylinder, a guide rail and a humerus head clamping mechanism.

Further, the platform support is of a hollow structure at the bottom and is fixed on the test platform, the air cylinder and the guide rail are fixed on the platform support, the air cylinder is located at the rear end of the humerus head clamping mechanism, the air cylinder is connected with the air pump pipeline, the humerus head clamping mechanism is fixed at the front end of the moving rod of the air cylinder, the guide rail is located at the two ends of the humerus head clamping mechanism, and the humerus head clamping mechanism is pushed by the air cylinder to perform linear reciprocating motion along the guide rail.

Furthermore, the glenoid fixing platform is cylindrical with a recess in the middle, threads are arranged on the outer surface of the cylindrical shape, and the glenoid fixing platform is inserted into a circular hole in the center of the movable platform of the parallel rotating platform and is locked by the threads of the fixing plate.

Furthermore, the lower end face of the artificial glenoid fixing platform is an inclined plane, the inclined plane and the horizontal plane form an included angle of 45 degrees, and the axis of the middle recess is normal to the lower end face and used for fixing the artificial glenoid.

The invention has the beneficial effects that:

the invention provides a shoulder joint prosthesis performance test platform which can effectively evaluate the basic performance of a shoulder joint prosthesis, can test the rotation angle of the shoulder joint prosthesis in each direction, can test the friction characteristic of the shoulder joint prosthesis, has strong functions, has certain guiding significance for the material selection and the structural design of the shoulder joint prosthesis, and fills the blank of the performance evaluation of the shoulder joint prosthesis.

The invention puts the test unit into the simulation bin, can simulate the friction condition of the real human body joint, utilizes the three-rotation parallel rotating platform to simulate the motion mode of the human body knee joint, and can simulate the friction and wear characteristics of the real human body shoulder joint.

According to the invention, under the regulation and control of the PLC intelligent control system, all links are mutually matched, the automation degree is high, the operation is simple, a plurality of abrasion tests can be simultaneously carried out for comparison or comparison, and the labor intensity of personnel is reduced.

Drawings

FIG. 1 is a schematic structural diagram of a shoulder joint prosthesis performance testing platform provided in this embodiment;

FIG. 2 is a schematic view of a parallel rotary platform provided in the present embodiment;

FIG. 3 is a schematic structural diagram of a simulation bin provided in this embodiment;

FIG. 4 is a PLC general framework diagram of a shoulder joint prosthesis performance test platform provided by the embodiment;

fig. 5 is a motion curve diagram applied to the artificial shoulder joint prosthesis provided by the embodiment.

Wherein: 1-test platform, 2-humerus head fixing platform, 3-air pump, 4-complete machine support, 5-parallel rotating platform, 6-glenoid fixing platform, 7-pressure sensor, 8-simulation cabin, 9-PLC, 10-PC upper computer, 201-platform support, 202-air cylinder, 203-guide rail, 204-humerus head clamping mechanism, 501-static platform, 502-moving platform, I-single open chain I, II-single open chain II, III-single open chain III, 801-metal frame, 802-glass window, 803-connecting plate, 804-sealing ring, 805-upper cover, 806-liquid inlet, 807-liquid outlet.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.

Example 1:

a shoulder prosthesis performance testing platform, as shown in fig. 1, comprising: the device comprises a test platform 1, a humerus head fixing platform 2, an air pump 3, a whole machine support 4, a parallel rotating platform 5, a glenoid fixing platform 6, a pressure sensor 7, a simulation bin 8, a PLC 9 and a PC upper computer 10. The humerus head fixing platform, the air pump and the whole machine support are fixed on the testing platform, the parallel rotating platform is fixed on the whole machine support, the glenoid fixing platform is fixed on the moving platform of the parallel rotating platform, the simulation bin is located at the upper end of the humerus head fixing platform and used for simulating real human body friction conditions when the shoulder joint prosthesis moves, the pressure sensor is arranged on the artificial shoulder joint prosthesis to be tested and used for collecting corresponding performance parameters of the artificial shoulder joint prosthesis, and the PLC and the PC upper computer are located on the testing platform and jointly complete intelligent control over the shoulder joint prosthesis performance testing platform.

Further, the humerus head fixing platform comprises a platform support 201, a cylinder 202, a guide rail 203 and a humerus head clamping mechanism 204, the platform support is of a hollow structure at the bottom and is fixed on the test platform, the cylinder and the guide rail are fixed on the platform support, the cylinder is located at the rear end of the humerus head clamping mechanism, the cylinder is connected with an air pump pipeline and used for pushing the humerus head to move upwards and providing a load applied during the movement of the platform, the humerus head clamping mechanism is fixed at the front end of a moving rod of the cylinder, the guide rail is located at two ends of the humerus head clamping mechanism, and the humerus head clamping mechanism is pushed by the cylinder to perform linear reciprocating motion along the guide rail.

Further, the parallel rotating platform is shown in fig. 2 and comprises a static platform 501, a moving platform 502, three single open chains I, ii, iii and three servo motors, the parallel rotating platform further comprises a specific topological structure, the topological structure of the parallel rotating platform is 2-RRR + SPS, and the single open chain I has a structure of 2-RRR + SPS

The single open chain II has the same structural arrangement as I, and the kinematic chain structure thereof

The structure of the single open chain III (S31/P3/S32) is equivalent to

The axes of the revolute pairs R11, R12 and R13 are intersected at the same point O1, the axes of the revolute pairs R21, R22 and R23 are intersected at the same point O2, the parallel rotary platform has three rotational degrees of freedom, namely rotation along an X axis, a Y axis and a Z axis, the driving pairs of the parallel motion platform are R11, R12 and P3 and are respectively driven by corresponding servo motors M1, M2 and M3.

Furthermore, the glenoid fixing platform is in a sunken cylindrical shape in the middle, threads are arranged on the outer surface of the cylindrical shape, the glenoid fixing platform is inserted into a round hole in the center of a movable platform of the parallel rotating platform and is locked by the threads of the fixing plate, the lower end face of the glenoid fixing platform is an inclined plane and has a 45-degree included angle with the horizontal plane, and the axis normal of the middle sunken part is normal to the lower end face and is used for fixing the artificial glenoid.

Further, the simulation chamber is shown in fig. 3, and comprises a metal frame 801, a glass window 802, a connecting plate 803, a sealing ring 804, an upper cover 805, a liquid inlet 806, and a liquid outlet 807, the connecting plate is disposed on the bottom surface of the metal frame, the connecting plate is provided with a connecting hole, used for matching with the humerus head fixing platform, the humerus head prosthesis passes through the connecting hole to enter the inside of the simulation cabin, the sealing ring is used for sealing, the glass window is arranged at the periphery of the metal frame to facilitate the direct observation of the test process, the upper cover is arranged at the upper end of the metal frame, used for reducing impurities from entering the inside of the simulation cabin, the upper cover places the glenoid fixing platform into the inside of the simulation cabin, but does not influence the movement of the glenoid fixing platform in all directions, and the liquid inlet and the liquid outlet are respectively arranged at the upper end and the lower end of the side wall of the metal frame and are used for adding and discharging the artificial joint liquid.

Further, the shoulder joint prosthesis performance test platforms can be arranged side by side and used for setting parallel tests and realizing comparison, and preferably 3-6 test stations can be arranged.

Example 2:

a shoulder joint prosthesis performance test platform is shown in the general structure of fig. 4, and the PLC is respectively connected with a PC upper computer, a servo motor M1, a servo motor M2, a servo motor M3, an air cylinder, an air pump and a pressure sensor. The PLC is electrically connected with the PC upper computer and is used for setting functional parameters such as test types, cycle times, applied loads, motion curves and the like; the PLC is electrically connected with the servo motor M1, the servo motor M2 and the servo motor M3 and is used for driving corresponding revolute pairs R11, R21 and P3 to operate in parallel, so that the rotation and the speed of the parallel rotating platform are controlled; the PLC is electrically connected with the air cylinder and the air pump and is used for controlling the height position of the humerus head fixing platform and the applied load; the PLC is electrically connected with the pressure sensor and is used for feeding back the load borne by the artificial shoulder joint prosthesis to form closed-loop control.

Example 3:

as shown in fig. 2, the number of parallel mechanism-sharing kinematic pairs m of the parallel rotary platform is 9, the number of members n is 8, and the degree of freedom (DOF) formula is used

Determining the degree of freedom (DOF) of the mechanism as F ═ 3, and the three degrees of freedom are rotation along the X axis, the Y axis and the Z axis respectively;

if the degree of freedom F' of the obtained new mechanism is 0, the F preselected kinematic pairs may be simultaneously the drive pairs. Since the degree of freedom of the mechanism is 3, the revolute pairs R11, R21 and P3 of the pre-selected 3 branches are driving pairs, and the revolute pairs R11, R21 and P3 are stiffened to obtain the degree of freedom F' of the mechanism after the stiffening is 0, so that the existing criterion of the driving pairs is met.

Example 4:

a shoulder joint prosthesis performance test platform adopts a servo control system of PC + PLC, and the PLC is communicated with a PC upper computer through an R232 serial port. One mode of operation of the platform is a mobility test for determining the mobility of the artificial shoulder prosthesis, primarily the range of motion that rotates on each face under a specified load.

The workflow of the test is as follows:

1) placing the glenoid prosthesis into a glenoid fixing platform for fixing, wherein the axis of the glenoid prosthesis is superposed with the axis of the middle depression; placing the humerus head prosthesis into a humerus head clamping mechanism of a humerus head fixing platform for fixing, wherein the glenoid prosthesis is not contacted with the humerus head prosthesis;

2) after the equipment is powered on, a control system is initialized, a rotating platform, an air pump, an air cylinder and a sensor are connected in parallel for setting, and a pressure sensor is attached to the upper surface of the humeral head prosthesis;

3) selecting the activity performance test, the direction to be measured, the applied load and other parameters on a PC upper computer, wherein the test conditions of the test scheme are as follows: applying a constant load of 600N, and testing the motion ranges of a sagittal plane (flexion-extension), a coronal plane (adduction-abduction) and a transverse plane (internal rotation-external rotation);

4) clicking on a PC upper computer to start, driving the humerus head prosthesis fixing platform to slowly move upwards by the air cylinder until the humerus head prosthesis is clamped into the ball socket prosthesis, feeding back the acquired parameters in real time by the pressure sensor, returning the parameters to the PC upper computer until the load reaches preset parameters, stopping moving the humerus head prosthesis fixing platform, and pulling out the pressure sensor;

5) the PC upper computer starts the parallel rotating platform, sequentially drives the ball socket prosthesis to move according to the selected direction, when the feedback resistance received by the servo motor reaches a limit value, the parallel rotating platform reversely moves, the maximum angle reached is determined to be the maximum movement angle of the tested artificial shoulder joint prosthesis in the direction, and after the tests in all directions are sequentially completed, the movement parameters are fed back to the PC upper computer for recording;

6) and resetting after all the specified operations are completed.

Example 5:

after the artificial shoulder joint is implanted into a body, a new biological friction pair is formed, the artificial shoulder joint is in a complex human body operation environment and simultaneously bears the comprehensive effects of tension, pressure, torsion, interfacial shear force, fatigue, abrasion and corrosion, and the implant is inevitably abraded or even fails after long-time use. Therefore, the existing common joint material is utilized to simulate the real human body friction condition, simulate the friction and wear characteristics of the artificial shoulder joint, develop the research on the aspects of the biological tribological performance of the artificial shoulder joint prosthesis and the like, evaluate the friction and wear characteristics of the joint material, explore and prepare the artificial shoulder joint material with better performance, improve the use quality of the artificial shoulder joint material, prolong the service time of the artificial shoulder joint material, and have important technical significance.

According to the shoulder joint prosthesis performance test platform provided by the invention, the other working mode of the platform is wear performance test, so that a real human body friction condition can be simulated, and the artificial shoulder joint prosthesis biological friction performance test can be completed. The test work flow is as follows:

3) selecting friction performance test on a PC upper computer, and parameters such as running frequency, a motion curve, total test revolution, applied load, time point for replacing artificial joint fluid and the like, wherein the test conditions of the test scheme are as follows: a constant load of 700N was applied, the motion curve is shown in FIG. 5, the test frequency was 0.5. + -. 0.1Hz, and the test ambient temperature was 25 ℃. The total test revolution is 200 ten thousand, after 50 ten thousand, 100 ten thousand, 150 ten thousand and 200 ten thousand cycles of operation, the machine is stopped to measure the weight of the humeral head prosthesis and the glenoid prosthesis, the worn part is photographed, the fresh artificial joint fluid is replaced, and simultaneously the data recording work is done.

5) adding enough artificial joint liquid through a liquid inlet on the side wall of the simulation bin, covering the artificial shoulder joint prosthesis and covering an upper cover;

6) the PC upper computer starts the parallel rotating platform, drives the ball socket prosthesis to do reciprocating motion according to a set motion curve, simulates the basic motion of human shoulder joints, automatically stops the machine after reaching the specified times, and performs operations such as data recording and artificial joint fluid replacement until all test times are finished;

7) and resetting after all the specified operations are completed.

The experimental results of this test are: the stage weight loss and the accumulated weight loss of the glenoid prosthesis tested in the test are shown in table 1 along with the change of the test period.

TABLE 1 staged and cumulative weight loss for glenoid prostheses

From the above table, it can be seen that the overall trend of the phase wear volume of the tested glenoid prosthesis is first significantly increased, then slowly decreased and finally gradually leveled off as the number of trial revolutions increases. The phase wear volume reaches a maximum at 50-100 ten thousand rubs. If the artificial shoulder joint prostheses in different materials or structural forms are transversely compared under the same experimental conditions, the friction characteristics of the shoulder joint prostheses can be compared on a plurality of parameters, and the superiority and inferiority of the shoulder joint prostheses can be evaluated.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention, and it is therefore to be understood that the invention is not limited by the scope of the appended claims.

Claims

1. A shoulder prosthesis performance testing platform, comprising: the device comprises a test platform, a humerus head fixing platform, an air pump, a complete machine support, a parallel rotating platform, a glenoid fixing platform, a pressure sensor, a simulation cabin, a PLC and a PC upper computer.

2. The platform of claim 1, wherein the humerus head fixing platform, the air pump and the complete machine support are fixed on the testing platform, the parallel rotating platform is fixed on the complete machine support, the glenoid fixing platform is fixed on the moving platform of the parallel rotating platform, the simulation chamber is positioned at the upper end of the humerus head fixing platform, the pressure sensor is arranged on the artificial shoulder joint prosthesis to be tested, and the PLC and the PC upper computer are positioned on the testing platform.

3. The platform of claim 1, wherein the humeral head fixation platform comprises a platform support, a cylinder, a guide, a humeral head clamping mechanism.

4. The platform of claim 1, wherein the platform support is a hollow structure fixed on the testing platform, the cylinder and the guide rail are fixed on the platform support, the cylinder is located at the rear end of the humerus head clamping mechanism, the cylinder is connected with the air pump pipeline, the humerus head clamping mechanism is fixed at the front end of the motion rod of the cylinder, the guide rail is located at the two ends of the humerus head clamping mechanism, and the humerus head clamping mechanism moves linearly and reciprocally along the guide rail under the pushing of the cylinder.

5. The platform of claim 1, wherein the socket fixing platform is a cylinder with a recess in the middle, threads are arranged on the outer surface of the cylinder, and the socket fixing platform is inserted into a circular hole in the center of the movable platform of the parallel rotating platform and locked by the threads of the fixing plate.

6. The platform of claim 1, wherein the socket retaining platform has a lower end surface that is beveled at a 45 ° angle to the horizontal, and the central depression has an axis normal to the lower end surface for retaining the artificial socket.