Lower limb full-length mechanical test system and method

Abstract

The invention discloses a lower limb full-length mechanical test system and method, which are characterized in that through a movable body, a test sample, a fixed base, a sliding guide rail and a ball screw, the load of knee joints and peripheral ligaments when the lower limb stands or bends at a certain angle is simulated, and the required information is measured by using corresponding sensors; and measuring the load of the knee joint and the peripheral ligament in the full length of the lower limb by using a corresponding sensor under the simulated gait, half squat, deep squat or stair climbing motion posture load. By the adoption of the technical scheme, the load of actual activity on the knee joint can be output and simulated, and the biomechanical state of the knee joint or the knee joint prosthesis in the full-length lower limb under the set condition can be scientifically, rapidly and completely simulated.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical health, and particularly relates to a full-length lower limb mechanical testing system and method. Background Art

[0002] In different movement postures, accurately measuring biomechanical parameters such as stress and strain, and load of the in-vivo knee joint or knee joint prosthesis is a major difficulty. And this information plays an important role in the research and development of more perfect knee joint prostheses and understanding the biomechanical movement laws of the knee joint. Internationally, knee joint prosthesis implants with a sensing system are implanted into patients for data collection. However, this method has a long process, high risk and is extremely complex, and will be restricted by human ethics. Existing testing means mainly use local knee joints or only knee joint prostheses, and cannot truly restore the actual load of the knee joint. There is a lack of instrument equipment for analyzing the biomechanical parameters of the knee joint in the full-length lower limb model under loads such as simulated gait walking, half-squatting, and deep-squatting. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a full-length lower limb mechanical testing system and method, which can output the load on the knee joint simulating actual activities, and can scientifically, quickly and completely simulate the biomechanical state of the knee joint or knee joint prosthesis in the full-length lower limb under established conditions.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A full-length lower limb mechanical testing system includes: a movable body, a test sample, a fixed base, a sliding guide rail, and a ball screw;

[0006] The movable body includes: a dust-proof machine cover, a mobile drive motor module, a synchronous belt, a movable body bottom plate, an adjustable synchronous belt pulley, a lead screw connection synchronous belt pulley, a force sensor, an acetabular socket, a biceps femoris knee flexion module, and a quadriceps femoris knee extension module; the test sample includes: bones and prostheses, muscles, and ligament replacement modules; the fixed base includes: a gastrocnemius knee flexion module, a fixed base bottom plate, legs, and a fixed pin module; the muscle drive modules of the biceps femoris knee flexion module, the quadriceps femoris knee extension module, and the gastrocnemius knee flexion module have the same structure, including: a module base, a simulated muscle drive motor, a drive wheel, and a fixed pulley.

[0007] Through the movable body, the test sample, the fixed base, the sliding guide rail, and the ball screw, the load on the knee joint and the surrounding ligaments when the lower limb stands or bends at a certain angle is simulated, and the required information is measured by corresponding sensors, and the load on the knee joint and the surrounding ligaments in the full-length lower limb is measured by corresponding sensors under load in movement postures such as gait, half-squatting, deep-squatting or going up stairs.

[0008] Preferably, the moving drive motor module inside the movable body is connected to a synchronous belt through a synchronous pulley, and the rotation is transmitted to the lead screw by connecting the synchronous pulley. The movable body moves up and down along the sliding guide through the ball screw; the adjustable synchronous pulley is used to adjust the tension of the synchronous belt and avoid the interference of the sliding guide on the synchronous belt; the dust-proof cover is used to protect the structure inside the movable body; the lower end of the acetabular socket is in contact connection with the femoral head, and the acetabular structure at the lower end of the acetabular socket restricts the degree of freedom of the femoral head, allowing it to rotate only in the acetabulum; the upper end of the acetabular socket is connected to the force sensor to measure the load force received by the acetabular socket.

[0009] Preferably, in the muscle drives of the biceps femoris knee flexion module, the quadriceps femoris knee extension module, and the gastrocnemius knee flexion module, the simulated muscle drive motor drives the driving wheel to rotate, driving the muscle and ligament replacement module to move around the fixed pulley; in the transmission system, the muscle force of the corresponding muscle module can be calculated through the torque feedback of the simulated muscle drive motor; the fixed pulley is used to control the direction of the muscle and ligament to conform to the corresponding anatomical laws; the installation positions of the biceps femoris knee flexion module and the quadriceps femoris knee extension module on the movable body floor, and the installation position of the gastrocnemius knee flexion module on the fixed base floor.

[0010] Preferably, the fixed pin module, the sliding guide, and the ball screw are fixed on the fixed base floor, and the pre-drilled holes at the distal end of the tibia and fibula at the lower end of the test sample are connected to the fixed pin module, allowing the distal end of the tibia and fibula to rotate freely around the C4 fixed pin module.

[0011] The present invention also provides a method for testing the full-length mechanics of the lower limb, including:

[0012] Step S1: Simulate the loading of the knee joint and surrounding ligaments when standing or flexing the knee at a certain angle, and measure the required information with the corresponding sensors;

[0013] Step S2: Simulate the loading of the knee joint and surrounding ligaments in the full length of the lower limb under the load of gait, half-squat, full-squat or stair-climbing movement postures, and measure with the corresponding sensors.

[0014] Preferably, in step S1, according to the body weight and geometric structure of the model, determine the load F on the lower limb and the femoral length L F , tibia length L T , and realize knee flexion at different angles by lowering the movable body; maintain the knee flexion angle, and the biceps femoris knee flexion module, the quadriceps femoris knee extension module, and the gastrocnemius knee flexion module apply muscle forces according to the test data. By gradually increasing the muscle force of the quadriceps femoris knee extension module, make the measurement result of the force sensor equal to the load F on the lower limb; realize the static measurement of the full length of the lower limb by inserting stress and strain gauges into the knee joint.

[0015] Preferably, in step S2, according to the geometric structure of the model, determine the femoral length L of the lower limb F, tibia length L T , by lowering the movable body A, the knee flexion during exercise is achieved; according to the muscle force data collected from the exercise process experiment, the discrete point method is adopted; by inserting the stress strain gauge into the knee joint, the measurement and collection of the required data during the dynamic exercise process are completed.

[0016] The present invention applies lower limb loads close to real working conditions in vitro, uses lower limb full-length models with different alignments and different prosthesis installation deviations to test, and measures the biomechanical parameters of the knee joint or knee joint prosthesis. The technical solution of the present invention can simulate the real load of the knee joint in vitro, avoiding dangerous and complicated clinical experimental testing processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0018] Figure 1 This is a structural diagram of a lower limb full-length mechanical testing system according to an embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of the upper structure of the movable body;

[0020] Figure 3 It is a schematic diagram of the lower structure of the movable body;

[0021] Figure 4 It is a schematic diagram of the fixed base structure;

[0022] Figure 5 This is a schematic diagram of the muscle force application module structure;

[0023] Figure 6 This is a schematic diagram for calculating the knee flexion angle;

[0024] Figure 7 This is a schematic diagram of the measurement with the knee flexed at 90°;

[0025] Figure 8 This is a static measurement flow chart;

[0026] Figure 9 This is a dynamic measurement flow chart. DETAILED DESCRIPTION

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0029] Embodiment 1:

[0030] As Figures 1 to 7 shown, the embodiment of the present invention provides a full-leg biomechanical testing system, including: a moving body A, a test sample B, a fixed base C, a sliding guide rail D, and a ball screw E.

[0031] The moving body A includes: a dust-proof machine cover A1, a moving drive motor module A2, a synchronous belt A3, a moving body base plate A4, an adjustable synchronous belt pulley A5, a lead screw connection synchronous belt pulley A6, a force sensor A7, an acetabular socket A8, a biceps femoris knee flexion module A9, and a quadriceps femoris knee extension module A10.

[0032] The test sample B includes: a bone and prosthesis B1, and a muscle and ligament replacement module B2.

[0033] The fixed base C includes: a gastrocnemius knee flexion module C1, a fixed base plate C2, legs C3, and a fixed pin module C4.

[0034] The biceps femoris knee flexion module A9, the quadriceps femoris knee extension module A10, and the gastrocnemius knee flexion module C1 have the same muscle drive structure, including: a module base F1, an analog muscle drive motor F2, a drive wheel F3, and a fixed pulley F4.

[0035] The moving drive motor module A2 inside the moving body A is connected to the synchronous belt A3 through a synchronous belt pulley, and the rotation is transmitted to the lead screw connection synchronous belt pulley A6. The moving body A moves up and down along the sliding guide rail D through the ball screw E. The adjustable synchronous belt pulley A5 is used to adjust the tension of the synchronous belt and at the same time avoid the interference of the sliding guide rail D on the synchronous belt A3. The dust-proof machine cover A1 is used to protect the internal structure of the moving body A. The lower end of the acetabular socket A8 is in contact connection with the femoral head. The acetabular structure at the lower end of the acetabular socket A8 restricts the degree of freedom of the femoral head so that it can only rotate in the acetabulum; the upper end of the acetabular socket A8 is connected to the force sensor A7 to measure the load force received by the acetabular socket A8. The drive motor of the moving drive motor module A2 is equipped with an encoder feedback. In the transmission system, the moving displacement of the moving body A can be calculated through the rotational displacement.

[0036] In the muscle drives of the biceps femoris knee flexion module A9, quadriceps femoris knee extension module A10, and gastrocnemius knee flexion module C1, the simulated muscle drive motor F2 is a motor with torque feedback. The simulated muscle drive motor F2 drives the drive wheel F3 to rotate, driving the muscle and ligament replacement module B2 to move around the fixed pulley F4. In the transmission system, the muscle force of the corresponding muscle module can be calculated through the torque feedback of the simulated muscle drive motor F2. The fixed pulley F4 is used to control the direction of the muscle and ligament replacement module B2 to make them conform to the corresponding anatomical laws. The installation positions of the biceps femoris knee flexion module A9 and quadriceps femoris knee extension module A10 on the moving body bottom plate A4, and the installation position of the gastrocnemius knee flexion module C1 on the fixed base bottom plate C2, can be reasonably adjusted through the reserved installation holes to adapt to the models with individual differences.

[0037] The fixed pin module C4, sliding guide D, and ball screw E are fixed on the fixed base bottom plate C2. The pre-drilled holes at the distal tibiofibular of the lower end of the test sample B are connected to the fixed pin module C4, enabling the distal tibiofibular to rotate freely around the fixed pin of the fixed pin module C4. According to the law of force balance of the human lower limb, the acetabular socket A8 and the fixed pin module C4 are on the same vertical line. The leg C3 supports the overall system.

[0038] As an implementation mode of the embodiment of the present invention, static measurement is realized through the lower limb full-length mechanical testing system, that is, simulating the load on the knee joint and surrounding ligaments when the lower limb stands or bends at a certain angle, and using the corresponding sensors to measure the required information. Specifically: as Figure 6 、 7 shown in Figure 8, according to the model body weight and geometric structure, determine the load F on the lower limb, the femoral length L F 、the tibial length L T , control the moving drive motor module A2 to rotate forward, so that the synchronous belt A3 drives the synchronous belt pulley A6 connected to the lead screw to rotate forward, causing the moving body A to descend a certain height. The height after descent is L, and the knee flexion angle is π - a, realizing knee flexion at different angles. Maintaining the knee flexion angle, control the rotation of each simulated muscle drive motor F2, and calculate the muscle tension of each muscle according to the feedback torque, that is: the biceps femoris knee flexion module A9, quadriceps femoris knee extension module A10, and gastrocnemius knee flexion module C1 apply muscle force according to the test data. By gradually increasing the muscle force of the quadriceps femoris knee extension module A10, make the measurement result of the force measuring sensor A7 equal to the load F on the lower limb. By inserting stress-strain gauges into the knee joint, etc., realize the static measurement of the lower limb full length.

[0039] As an implementation mode of the embodiment of the present invention, dynamic measurement is realized through the lower limb full-length mechanical testing system, that is, simulating the load on the knee joint and surrounding ligaments in the lower limb full length under movement postures such as gait, half squat, full squat, or going up stairs, and specifically: asFigure 6 , 7 , as shown in Figure 9, determine the length L of the lower limb femur according to the model geometric structure F and the length L of the tibia T , control the mobile drive motor module A2 to rotate forward, so that the synchronous belt A3 drives the lead screw-connected synchronous pulley A6 to rotate forward, causing the moving body A to descend a certain height. The height after descent is L, and the knee flexion angle is π - a to achieve knee flexion at different angles. According to the muscle force data collected during the motion process experiment, the discrete point method is used. For example: divide the motion process into 10 points, and control each muscle force to reach the corresponding collected force according to the above control muscle force process. Mainly control the muscle force of the quadriceps femoris knee extension module A10 so that the measurement result of the force sensor A7 is equal to the load force collected in the experiment, then complete the data measurement at this point; then control the moving body A to descend a certain distance to achieve further knee flexion, and sequentially measure the remaining discrete points. By inserting stress and strain gauges into the knee joint, etc., complete the measurement and collection of the data required during the dynamic motion process

[0040] Embodiment 2:

[0041] The embodiment of the present invention also provides a method for testing the mechanics of the entire lower limb, including:

[0042] Step S1: Simulate the load on the knee joint and surrounding ligaments when the lower limb stands or bends at a certain angle, and use the corresponding sensors to measure the required information;

[0043] Step S2: Simulate the load on the knee joint and surrounding ligaments in the entire lower limb under the load of gait, half-squat, full-squat or stair-climbing motion postures, and use the corresponding sensors to measure the load

[0044] As an implementation manner of the embodiment of the present invention, in step S1, according to the model body weight and geometric structure, determine the load F on the lower limb, the length L of the femur F and the length L of the tibia T , by lowering the moving body, achieve knee flexion at different angles; maintain the knee flexion angle, and apply muscle forces to the biceps femoris knee flexion module, quadriceps femoris knee extension module, and gastrocnemius knee flexion module according to the test data. By gradually increasing the muscle force of the quadriceps femoris knee extension module, make the measurement result of the force sensor equal to the load F on the lower limb; by inserting stress and strain gauges into the knee joint, achieve static measurement of the entire lower limb

[0045] As an implementation manner of the embodiment of the present invention, in step S2, according to the model geometric structure, determine the length L of the lower limb femur F and the length L of the tibia T, by lowering the moving body A, knee flexion during movement is achieved; according to the muscle force data collected through experiments during the movement process, the discrete point method is adopted; by inserting stress-strain gauges into the knee joint, the measurement and collection of the data required during the dynamic movement process are completed.

[0046] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A full-length lower limb mechanical testing system, characterized in that, Including: A moving body, a test sample, a fixed base, a sliding guide rail, and a ball screw; The moving body includes: a dust-proof cover, a moving drive motor module, a synchronous belt, a moving body bottom plate, an adjustable synchronous belt pulley, a lead screw connecting synchronous belt pulley, a force sensor, an acetabular socket, a biceps femoris knee flexion module, and a quadriceps femoris knee extension module; The test sample includes: bones and prostheses, muscles, and ligament replacement modules; The fixed base includes: a gastrocnemius knee flexion module, a fixed base bottom plate, legs, and a fixed pin module; The muscle drive modules of the biceps femoris knee flexion module, the quadriceps femoris knee extension module, and the gastrocnemius knee flexion module have the same structure and include: a module base, a simulated muscle drive motor, a drive wheel, and a fixed pulley; Through the moving body, the test sample, the fixed base, the sliding guide rail, and the ball screw, the loads on the knee joint and the surrounding ligaments are simulated when the lower limb stands or bends at a certain angle, and the corresponding sensors are used to measure the required information. Also, under the load of gait, half-squat, full-squat, or stair-climbing movement postures, the corresponding sensors are used to measure the loads on the knee joint and the surrounding ligaments throughout the lower limb.

2. The full-length lower limb mechanical testing system according to claim 1, characterized in that The moving drive motor module inside the moving body is connected to the synchronous belt through the synchronous belt pulley, transfers the rotation to the lead screw connecting synchronous belt pulley, and makes the moving body move up and down along the sliding guide rail through the ball screw; The adjustable synchronous belt pulley is used to adjust the tension of the synchronous belt and at the same time avoid the interference of the sliding guide rail on the synchronous belt; The dust-proof cover is used to protect the internal structure of the moving body; The lower end of the acetabular socket is in contact connection with the femoral head, and the acetabular structure at the lower end of the acetabular socket restricts the freedom of the femoral head so that it can only rotate in the acetabulum; The upper end of the acetabular socket is connected to the force sensor to measure the load force received by the acetabular socket.

3. The full-length lower limb mechanical testing system according to claim 2, wherein In the muscle drive of the biceps femoris knee flexion module, the quadriceps femoris knee extension module, and the gastrocnemius knee flexion module, the simulated muscle drive motor drives the drive wheel to rotate, and drives the muscle and ligament replacement modules to move around the fixed pulley; In the transmission system, the muscle force of the corresponding muscle module can be calculated through the torque feedback of the simulated muscle drive motor; The fixed pulley is used to control the direction of the muscles and ligaments to conform to the corresponding anatomical laws; The installation positions of the biceps femoris knee flexion module and the quadriceps femoris knee extension module on the moving body bottom plate, and the installation position of the gastrocnemius knee flexion module on the fixed base bottom plate.

4. The full-leg biomechanical testing system according to claim 3, characterized in that, The fixed pin module, the sliding guide rail, and the ball screw are fixed on the fixed base bottom plate. The distal tibiofibular joint of the test sample at the lower end is pre-drilled and connected to the fixed pin module, so that the distal tibiofibular joint can rotate freely around the C4 fixed pin module.

5. A full-leg mechanical testing method, characterized in that Including: Step S1: Simulate the loads on the knee joint and the surrounding ligaments when the lower limb stands or bends at a certain angle, and use the corresponding sensors to measure the required information; Step S2: Simulate the loads on the knee joint and the surrounding ligaments throughout the lower limb under the load of gait, half-squat, full-squat, or stair-climbing movement postures, and use the corresponding sensors to measure.

6. The full-length lower limb mechanical testing method according to claim 5, wherein, In step S1, the load F of the lower limb and the femur length L are determined according to the model weight and geometric structure. F , tibia length L T By lowering the movable body, different angles of knee flexion can be achieved; maintaining the knee flexion angle, the biceps femoris knee flexion module, the quadriceps femoris knee extension module, and the gastrocnemius knee flexion module apply muscle force according to the test data, and by gradually increasing the muscle force of the quadriceps femoris knee extension module, the measurement result of the force sensor is made equal to the load F of the lower limb; by inserting a stress strain gauge into the knee joint, static measurement of the entire length of the lower limb can be achieved.

7. The full-length lower limb mechanical testing method according to claim 6, wherein, In step S2, according to the model geometric structure, the length L of the lower limb femur is determined F , and the length L of the tibia T . By lowering the moving body A, knee flexion during movement is achieved; according to the muscle force data collected through experiments during the movement process, the discrete point method is adopted; by inserting stress-strain gauges into the knee joint, the measurement and collection of the data required during the dynamic movement process are completed.

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