Artificial knee joint friction and wear experimental device

Abstract

This invention provides an experimental device for friction and wear testing of an artificial knee joint, belonging to the field of material friction and wear technology. It includes a lifting module, with a femoral clamping module at its top. The femoral clamping module contains a polyurethane elastomer sealed chamber, and a tibial clamping module is connected below this chamber. An intelligent temperature-controlled circulating hydraulic pump is located on one side of the polyurethane elastomer sealed chamber. This invention achieves reciprocating motion through a reversing valve control. Combined with sub-millimeter precision adjustment of the hydraulic actuator and differentiated installation positions, it realizes high-precision flexion, extension, and torsional movements of the artificial knee joint. A stable base load is provided by a central hydraulic loading module, while the unnecessary torque from the dual electromagnetic loading modules cancels each other out. Simultaneously, instantaneous impact force is superimposed on the stable hydraulic load through instantaneous power switching, enriching the loading methods of the experimental device for friction and wear testing of an artificial knee joint.

Description

Technical Field

[0001] This utility model belongs to the field of material friction and wear technology, and specifically relates to an experimental device for friction and wear of artificial knee joints. Background Technology

[0002] An artificial knee joint (also known as a knee prosthesis) is a medical device surgically implanted into the human body to replace a diseased or damaged knee joint, aiming to restore joint function, relieve pain, and improve patients' quality of life. An artificial knee joint friction and wear testing device is a specialized testing machine capable of accurately measuring the friction and wear performance of artificial knee joint prostheses. It aims to establish a testing platform that more closely approximates the actual working conditions of the human knee joint, providing a scientific basis for prosthesis performance optimization and clinical evaluation. However, at present, at least three problems need to be solved in the testing of the friction and wear performance of artificial knee joint prostheses: 1. The simplified reciprocating motion in the experiment differs significantly from the actual knee joint motion, especially since the reciprocating motion of the knee joint often involves changes in the force angle such as torsional motion; 2. When the human body performs explosive movements such as jumping, the knee joint is subjected to instantaneous high-load impact. Existing testing systems mostly use continuous and stable loading methods, making it difficult to realistically simulate dynamic impact loads; 3. Existing friction and wear experiments are mostly conducted in an air environment, which differs significantly from the actual physiological environment of the human knee joint. This environmental difference has a decisive impact on the lubrication characteristics, friction coefficient, and wear mechanism of the joint. Therefore, it is necessary to design a novel experimental device for artificial knee joint friction and wear to improve the accuracy and scientific validity of the experimental results.

[0003] To establish a friction and wear experimental testing platform that more closely resembles the actual working conditions of the human knee joint, and to address issues such as simple motion trajectories, difficulty in achieving instantaneous high-load impact loading, and significant differences in experimental testing conditions, this invention proposes an artificial knee joint friction and wear experimental device. The device aims to achieve the following during experimental testing: First, based on the coordinated drive of a hydraulic actuator and a hydraulic motor, precise angle adjustment and reciprocating torsional motion of the output shaft are achieved, meeting the biomimetic motion requirements of knee joint prosthesis flexion-extension, torsion, and reciprocating friction experiments; Second, through an electromagnetic loading module, transient force step changes during human knee joint movement are simulated, reproducing the mechanical characteristics under physiological load conditions; Third, through a polyurethane elastomer sleeve and an intelligent temperature-controlled circulating hydraulic pump, a fluid environment close to that of the human knee joint is constructed, achieving comprehensive simulation of temperature and lubrication. Utility Model Content

[0004] The purpose of this invention is to provide an experimental device for testing the friction and wear of an artificial knee joint, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] An experimental device for testing friction and wear of an artificial knee joint, comprising:

[0007] The lifting module includes a femoral clamping module at its top, with a polyurethane elastomer sealed chamber inside. A tibial clamping module is connected below the polyurethane elastomer sealed chamber. An intelligent temperature-controlled circulating hydraulic pump is installed on one side of the polyurethane elastomer sealed chamber. The lifting module contains a hydraulic actuator for driving the femoral clamping module to move up and down. A hydraulic-electromagnetic composite loading system is installed on the outer surface of the femoral clamping module. Femoral and tibial experimental prostheses are fixed to the femoral and tibial clamping modules, respectively. The upper and lower ends of the polyurethane elastomer sealed chamber are sealed with O-rings.

[0008] As a preferred embodiment of this utility model, the lifting module includes a lifting system hydraulic pump and a lifting system lower support. The lifting system hydraulic pump and the lifting system lower support are connected by a cylindrical pin to form a lifting system hinge structure. The spherical connection point connected to the femoral clamping module is used to realize the installation and fixation of the femoral experimental prosthesis.

[0009] As a preferred embodiment of this utility model, the femoral clamping module is provided with an open circular hole, which cooperates with the spherical connection to realize the installation and fixation of the femoral clamping module. The femoral clamping module is also provided with an electromagnetic loading module fixing hole and a hydraulic loading module fixing hole. The femoral clamping module is provided with a hydraulic actuator flexion and extension fixing part for fixing the hydraulic actuator and realizing the reproduction of the human knee joint flexion and extension movement. The surface of the femoral clamping module is provided with a hydraulic module force application plate groove to ensure uniform distribution of loading force.

[0010] As a preferred embodiment of this utility model, the tibial clamping module is provided with a tibial fixing pin at the bottom for fixing the tibial experimental prosthesis. The tibial clamping module is also provided with a hydraulic actuator torsion fixing part for use with the hydraulic actuator to fix the hydraulic actuator and realize the reproduction of the human knee joint torsion movement.

[0011] As a preferred embodiment of this utility model, the intelligent temperature-controlled circulating hydraulic pump includes an outlet pipe and a return pipe, which are connected to a polyurethane elastomer sealed chamber. The surface of the intelligent temperature-controlled circulating hydraulic pump is provided with a circulating pump and a temperature control module, which are used to simulate the human body temperature environment and drive the simulated body fluid to circulate in the system.

[0012] As a preferred embodiment of this utility model, the hydraulic-electromagnetic composite loading system comprises an electromagnetic loading module, a hydraulic loading module, a hydraulic loading module force application plate, and an electromagnetic loading module force application shaft. The electromagnetic loading module is connected to the hydraulic loading module through the electromagnetic loading module force application shaft. The hydraulic loading module and the hydraulic loading module force application plate are an integral unit used to provide the basic load.

[0013] As a preferred embodiment of this invention, the upper and lower ends of the polyurethane elastomer sealed chamber are sealed with O-rings to ensure that the simulated body fluid does not leak during the experiment and to maintain the sealing and stability of the experimental system.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] I. This utility model designs a dual-motor drive system for hydraulic actuators driven by hydraulic motors. Reciprocating motion is achieved through directional control valves. By combining sub-millimeter precision adjustment of the hydraulic actuators with differentiated installation positions of the hydraulic actuators, high-precision flexion, extension and torsion movements of the artificial knee joint are realized.

[0016] II. This utility model designs a hydraulic-electromagnetic composite loading system. The central hydraulic loading module provides a stable base load, while the dual electromagnetic loading modules cancel each other out the unnecessary torque. At the same time, the instantaneous impact force is superimposed on the stable hydraulic load by instantaneously switching on and off the power, which enriches the loading methods of the artificial knee joint friction and wear test device.

[0017] III. This utility model designs a composite system consisting of a polyurethane elastomer (PCU) sealed chamber and an intelligent temperature-controlled circulation system. The polyurethane elastomer sleeve isolates external interference and stores simulated body fluid, while the intelligent temperature-controlled circulating hydraulic pump realizes body fluid circulation and constant temperature (37±1℃), further restoring the actual working conditions of the artificial knee joint. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0019] Figure 1 This is a schematic diagram of the overall front structure of this utility model;

[0020] Figure 2 This is a cross-sectional view of the internal parts of the device on the right side of the front of this utility model;

[0021] Figure 3This is a schematic diagram of the closed cavity structure of the polyurethane elastomer of this utility model;

[0022] Figure 4 This is a schematic diagram of the elevator module structure of this utility model;

[0023] Figure 5 This is a schematic diagram of a half-section of the femoral clamping module of this utility model;

[0024] Figure 6 This is a half-sectional structural diagram of the tibial clamping module of this utility model;

[0025] Figure 7 This is a schematic diagram of the hydraulic-electromagnetic composite loading system of this utility model;

[0026] Figure 8 This is a schematic diagram of the assembly of the intelligent temperature-controlled circulating hydraulic pump of this utility model.

[0027] In the diagram: 1. Lifting module; 2. Femoral clamping module; 3. Polyurethane elastomer sealed chamber; 4. Tibial clamping module; 5. Intelligent temperature-controlled circulating hydraulic pump; 6. Hydraulic actuator; 7. Hydraulic-electromagnetic composite loading system; 8. Femoral experimental prosthesis; 9. Tibial experimental prosthesis; 10. O-ring; 101. Lifting system hydraulic pump; 102. Lifting system hinge structure; 103. Lifting system lower support; 104. Spherical connection; 201. Opening hole; 202. 203. Fixing hole for electromagnetic loading module; 204. Fixing hole for hydraulic loading module; 205. Fixing point for flexion and extension of hydraulic actuator; 406. Slot for force application plate of hydraulic module; 407. Tibial fixation pin; 408. Fixing point for torsion of hydraulic actuator; 509. Outlet pipe; 5002. Return pipe; 501. Circulation pump; 502. Temperature control module; 703. Electromagnetic loading module; 704. Hydraulic loading module; 705. Force application plate of hydraulic loading module; 706. Force application shaft of electromagnetic loading module. Detailed Implementation

[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0031] Example

[0032] Reference Figures 1 to 8 This is an embodiment of the present invention, which provides an experimental device for testing the friction and wear of an artificial knee joint, comprising:

[0033] The elevator module 1 has a femoral clamping module 2 at its top. The femoral clamping module 2 has a polyurethane elastomer sealed chamber 3 inside. The tibial clamping module 4 is connected below the polyurethane elastomer sealed chamber 3. An intelligent temperature-controlled circulating hydraulic pump 5 is installed on one side of the polyurethane elastomer sealed chamber 3. The elevator module 1 has a hydraulic actuator 6 inside for driving the femoral clamping module 2 to move up and down. The outer surface of the femoral clamping module 2 is equipped with a hydraulic electromagnetic composite loading system 7. Femoral experimental prosthesis 8 and tibial experimental prosthesis 9 are fixed to the femoral clamping module 2 and tibial clamping module 4 respectively. The upper and lower ends of the polyurethane elastomer sealed chamber 3 are sealed with O-rings 10.

[0034] Specifically, the lifting module 1 includes a lifting system hydraulic pump 101 and a lifting system lower support 103. The lifting system hydraulic pump 101 and the lifting system lower support 103 are connected by a cylindrical pin to form a lifting system hinge structure 102 and a spherical connection 104 connected to the femoral clamping module 2, which is used to realize the installation and fixation of the femoral experimental prosthesis 8.

[0035] Furthermore, the femoral clamping module 2 is provided with an open circular hole 201, which cooperates with the spherical connection 104 to realize the installation and fixation of the femoral clamping module 2. The femoral clamping module 2 is also provided with an electromagnetic loading module fixing hole 202 and a hydraulic loading module fixing hole 203. The femoral clamping module 2 is provided with a hydraulic actuator flexion and extension fixing part 204 for fixing the hydraulic actuator 6 to realize the reproduction of the human knee joint flexion and extension movement. The surface of the femoral clamping module 2 is provided with a hydraulic module force application plate groove 205 to ensure uniform distribution of loading force.

[0036] Furthermore, the tibial clamping module 4 has a tibial fixation pin 401 at the bottom for fixing the tibial experimental prosthesis 9. The tibial clamping module 4 also has a hydraulic actuator torsion fixing part 402 for use with the hydraulic actuator 6 to fix the hydraulic actuator 6 and realize the reproduction of the human knee joint torsion movement.

[0037] Furthermore, the intelligent temperature-controlled circulating hydraulic pump 5 includes an outlet pipe 501 and a return pipe 502, which are connected to the polyurethane elastomer sealed chamber 3. The surface of the intelligent temperature-controlled circulating hydraulic pump 5 is provided with a circulating pump 503 and a temperature control module 504, which are used to simulate the human body temperature environment and drive the simulated body fluid to circulate in the system.

[0038] Preferably, the hydraulic-electromagnetic composite loading system 7 consists of an electromagnetic loading module 701, a hydraulic loading module 702, a hydraulic loading module force application plate 703, and an electromagnetic loading module force application shaft 704. The electromagnetic loading module 701 is connected to the hydraulic loading module 702 through the electromagnetic loading module force application shaft 704. The hydraulic loading module 702 and the hydraulic loading module force application plate 703 are an integral unit used to provide the basic load.

[0039] It should be noted that the upper and lower ends of the polyurethane elastomer sealed chamber 3 are sealed with O-rings 10 to ensure that the simulated body fluid does not leak during the experiment and to maintain the sealing and stability of the experimental system.

[0040] In use, the overall structure is supported and its height is adjusted via the lifting module 1. A femoral clamping module 2 is installed at the top of the lifting module 1. The femoral clamping module 2 contains a polyurethane elastomer sealed chamber 3 to simulate the environment of a human knee joint. A tibial clamping module 4 is connected below this sealed chamber to clamp the tibial experimental prosthesis 9, and a tibial fixation pin 401 is located at its bottom to ensure secure installation of the prosthesis. An intelligent temperature-controlled circulating hydraulic pump 5 is installed on one side of the sealed chamber, connected to the chamber via an outlet pipe 501 and a return pipe 502. The circulating pump 503 drives the circulation of simulated body fluids, while the temperature control module 504 maintains the temperature inside the chamber close to human body temperature, thus creating experimental conditions close to a real physiological environment. The lifting module 1... The system includes a lifting system hydraulic pump 101 and a lifting system lower support 103, which together form a lifting system hinge structure 102 via a cylindrical pin, achieving stable support and flexible adjustment during the lifting process. The femoral clamping module 2 is connected to the lifting module via a spherical connector 104, facilitating angle adjustment and installation fixation in three-dimensional space. The femoral clamping module 2 has an open circular hole 201, which cooperates with the spherical connector 104 to complete the module's installation and positioning. In addition, the module also has an electromagnetic loading module fixing hole 202 and a hydraulic loading module fixing hole 203, facilitating the integrated installation of the loading module. The hydraulic actuator flexion / extension fixing point 204 is used to connect the hydraulic actuator 6 to simulate the flexion / extension movement of the knee joint. A hydraulic module force application plate groove 205 is provided on the module surface. This helps to distribute the loading force evenly, improving the accuracy and stability of the experiment. The tibial clamping module 4 also has a hydraulic actuator torsion fixing point 402 for connecting the hydraulic actuator 6 to simulate the torsional movement of the knee joint. By combining flexion and extension and torsion movements, the device can reproduce the multi-degree-of-freedom movement state of the human knee joint in daily activities, thus more realistically reflecting the wear and tear of the prosthesis in actual use. The hydraulic-electromagnetic composite loading system 7, as the core of the loading system, consists of an electromagnetic loading module 701, a hydraulic loading module 702, a hydraulic loading module force plate 703, and an electromagnetic loading module force shaft 704. The electromagnetic loading module 701 is connected to the hydraulic loading module through the force shaft, and the hydraulic loading module and the force plate are... The overall structure provides the basic load and enables dynamic loading. This system can flexibly adjust the magnitude and frequency of the loading force to meet the loading requirements under different experimental conditions, simulating the stress on the knee joint during different states such as walking and climbing stairs. During the experiment, the femoral experimental prosthesis 8 and the tibial experimental prosthesis 9 are fixed to the femoral clamping module 2 and the tibial clamping module 4, respectively, and are driven by the hydraulic actuator 6 to perform flexion, extension, and torsion movements. Simultaneously, the hydraulic-electromagnetic composite loading system 7 applies dynamic loads to simulate the joint stress state during human movement. The intelligent temperature-controlled circulating hydraulic pump 5 continuously delivers simulated body fluid into the polyurethane elastomer sealed chamber 3, maintaining the chamber's temperature and humidity environment, simulating the lubrication and nutrition functions of human synovial fluid. Throughout the entire experiment...O-ring 10 ensures the seal of the upper and lower end faces of the enclosed chamber, preventing liquid leakage and ensuring the continuity of the experiment and the safe operation of the equipment.

[0041] In summary, the high-precision flexion, extension, and torsion movements of the artificial knee joint are achieved through the dual-motor drive system of the hydraulic actuator 6. The hydraulic-electromagnetic composite loading system 7 achieves impact loading while ensuring stable load. Furthermore, the polyurethane elastomer sealed chamber 3 and the intelligent temperature-controlled circulating hydraulic pump 5 simulate the human synovial fluid environment, improving the simulation accuracy of the experiment. The overall structural design is reasonable, and the control precision is high, making it suitable for long-term friction and wear performance testing of artificial knee joint prostheses.

[0042] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of this utility model. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structural equivalents but also equivalent structures. Without departing from the scope of this invention, other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments. Therefore, this invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0043] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the present invention as currently considered, or those features that are not relevant to implementing the present invention) may be omitted.

[0044] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0045] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An experimental device for testing the friction and wear of an artificial knee joint, characterized in that: include, The elevator module (1) has a femoral clamping module (2) at its top. The femoral clamping module (2) has a polyurethane elastomer sealed chamber (3) inside. The tibial clamping module (4) is connected below the polyurethane elastomer sealed chamber (3). A smart temperature-controlled circulating hydraulic pump (5) is provided on one side of the polyurethane elastomer sealed chamber (3). The elevator module (1) has a hydraulic actuator (6) inside for driving the femoral clamping module (2) to move up and down. The outer surface of the femoral clamping module (2) is provided with a hydraulic electromagnetic composite loading system (7). The femoral clamping module (2) and the tibial clamping module (4) are respectively fixed with a femoral experimental prosthesis (8) and a tibial experimental prosthesis (9). The upper and lower ends of the polyurethane elastomer sealed chamber (3) are sealed with O-rings (10).

2. The artificial knee joint friction and wear testing device according to claim 1, characterized in that: The lifting module (1) includes a lifting system hydraulic pump (101) and a lifting system lower support (103). The lifting system hydraulic pump (101) and the lifting system lower support (103) are connected by a cylindrical pin to form a lifting system hinge structure (102) and a spherical connection (104) connected to the femoral clamping module (2), which is used to realize the installation and fixation of the femoral experimental prosthesis (8).

3. The artificial knee joint friction and wear testing device according to claim 2, characterized in that: The femoral clamping module (2) is provided with an open circular hole (201). The open circular hole (201) cooperates with the spherical connection (104) to realize the installation and fixation of the femoral clamping module (2). The femoral clamping module (2) is also provided with an electromagnetic loading module fixing hole (202) and a hydraulic loading module fixing hole (203). The femoral clamping module (2) is provided with a hydraulic actuator flexion and extension fixing part (204) for fixing the hydraulic actuator (6) to realize the reproduction of the flexion and extension movement of the human knee joint. The surface of the femoral clamping module (2) is provided with a hydraulic module force application plate groove (205) to ensure uniform distribution of loading force.

4. The artificial knee joint friction and wear testing device according to claim 3, characterized in that: The tibial clamping module (4) is provided with a tibial fixation pin (401) at the bottom for fixing the tibial experimental prosthesis (9). The tibial clamping module (4) is also provided with a hydraulic actuator torsion fixing part (402) for use with the hydraulic actuator (6) to fix the hydraulic actuator (6) and realize the reproduction of the human knee joint torsion movement.

5. The artificial knee joint friction and wear testing device according to claim 4, characterized in that: The intelligent temperature-controlled circulating hydraulic pump (5) includes an outlet pipe (501) and a return pipe (502), which are connected to a polyurethane elastomer sealed chamber (3). The surface of the intelligent temperature-controlled circulating hydraulic pump (5) is provided with a circulating pump (503) and a temperature control module (504) for simulating the human body temperature environment and driving the simulated body fluid to circulate in the system.

6. The artificial knee joint friction and wear testing device according to claim 5, characterized in that: The hydraulic-electromagnetic composite loading system (7) consists of an electromagnetic loading module (701), a hydraulic loading module (702), a hydraulic loading module force plate (703), and an electromagnetic loading module force shaft (704). The electromagnetic loading module (701) is connected to the hydraulic loading module (702) through the electromagnetic loading module force shaft (704). The hydraulic loading module (702) and the hydraulic loading module force plate (703) are an integral unit used to provide the basic load.

7. The artificial knee joint friction and wear testing device according to claim 6, characterized in that: The upper and lower ends of the polyurethane elastomer sealed chamber (3) are sealed with O-rings (10) to ensure that the simulated body fluid does not leak during the experiment and to maintain the sealing and stability of the experimental system.

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