Biomechanical experiment device for evaluating movement stability of shoulder joint

Abstract

The invention discloses a biomechanical experimental device for evaluating shoulder joint movement stability, an industrial robot in the biomechanical experimental device is arranged on one side of a muscle loading routing system, a shoulder blade fixing rack is arranged in the muscle loading routing system, a shoulder blade of a shoulder joint specimen is fixedly mounted on the shoulder blade fixing rack, and the shoulder blade of the shoulder joint specimen is fixedly mounted on the shoulder blade fixing rack. According to the shoulder blade fixing rack, the abduction angle and the front / rear inclination angle of shoulder blade installation can be adjusted; the humerus of the shoulder joint specimen is fixedly installed at the tail end of the industrial robot through a customized humerus clamp, and the customized humerus clamp can adjust the humerus clamping position and the humerus internal and external rotation angle; the muscle loading routing system can adjust the direction and height of a fixed pulley through a two-connecting-rod mechanism and a fixed pulley fixing rod, so that the direction of initial muscle tension applied by hanging a heavy object is consistent with the physiological direction of a muscle action line, the muscle stress trend can be simulated, and the muscle stress in-vivo condition is closer to that of muscle stress.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and particularly relates to a biomechanical experimental device for evaluating the motion stability of the shoulder joint. Background Art

[0002] The stability of the shoulder joint mainly refers to the stability of the glenohumeral joint, that is, the position of the humeral head is always maintained within the physiological range relative to the glenoid cavity. The shoulder joint is the joint with the largest range of motion in the human body, and shoulder joint stability plays an important role in maintaining normal functional shoulder joint movement. Shoulder joint instability is likely to cause shoulder joint dislocation, and then cause problems such as fractures, seriously affecting the daily life of patients. The rotator cuff muscles are of great significance for maintaining the motion stability of the shoulder joint. Therefore, by combining advanced electromechanical technology with biomechanics and simulating shoulder joint movement in vitro, the contribution degree of each part of the rotator cuff muscles in maintaining the motion stability of the shoulder joint can be specifically analyzed. By studying the kinematics and dynamics of the shoulder joint in normal, pathological, and treatment states, as well as the mechanism of the rotator cuff muscles in maintaining the motion stability of the shoulder joint, it is of great significance for the repair of rotator cuff muscle injuries, and understanding the relevant content of shoulder joint osteo-muscle biomechanics is also crucial for understanding the pathology of the shoulder joint and formulating new surgical repair strategies. However, at present, the mechanism by which the rotator cuff muscles maintain the motion stability of the shoulder joint has not been clearly and specifically expressed. More often, the active movement of the shoulder joint is achieved through muscle loading, which is not completely consistent with the biomechanical mechanism by which the rotator cuff muscles maintain the humeral head within the glenoid cavity through muscle tension.

[0003] For example, patent (CN112816329A) discloses a shoulder joint biomechanical experimental platform, including: a bracket, a base, a scapula fixation and muscle loading unit, a humerus clamping and rotation unit, a humerus motion guiding arc frame, and a humerus displacement detection unit. The active movement of the shoulder joint is achieved by applying loads to each part of the rotator cuff muscles through a cylinder. However, the shoulder joint movement achieved by this device is simple, and it can only achieve abduction and adduction movements of the shoulder joint in a single plane, and cannot simulate the complex movements of the shoulder joint; the method of adjusting the baffle is used to adjust the direction of the muscle loading force line, but using this method will cause the influence of the frictional force between the surgical suture and the adjusting baffle.

[0004] "Quantitative Assessment of Glenohumeral Translation after Anterior Shoulder Dislocation and Subsequent Arthroscopic Bankart Repair" by Marquardt B et al. (The American Journal of Sports Medicine, 2006) used a robotic arm-assisted shoulder simulator to measure the anterior-posterior translation and external rotation of the shoulder joint at 0° and 90° of abduction in the intact, dislocated, and Bankart injury-repaired conditions of the shoulder joint. By introducing a robotic arm, the abduction movement of the shoulder joint was reproduced. However, the shoulder joint motion simulation was relatively simple, and the rotator cuff muscles around the shoulder joint were not activated, so the physiological effects of the musculoskeletal system could not be reflected.

[0005] "In Vitro Simulation of Shoulder Motion Driven by Three-Dimensional Scapular and Humeral Kinematics" by Sulkar H et al. (ASME. J Biomech Eng. May 2022) used a robot to simulate the specific three-dimensional motion trajectories of the scapula and humerus of healthy subjects on cadaveric arms, and used kinematic positioning accuracy, repeatability, and muscle force repeatability indicators to characterize the system performance; analyzed the influence of the differences between the input motion and cadaveric specimens on shoulder motion simulation. The scapular and humeral motions of a specific population were collected, and the robot was used to control the scapula and humerus respectively to reproduce the motion trajectories. However, this shoulder joint motion was a step motion and could not truly reflect the shoulder joint dynamics.

[0006] "The effect of muscle loading on the kinematics of in vitro glenohumeral abduction" by Kedgley AE et al. (Journal of biomechanics, 2007) used air cylinders to load the deltoid muscle and rotator cuff muscle groups to achieve the active movement of the shoulder joint, evaluated the influence of four different muscle loading rates on active shoulder joint abduction, approximately replicated the in vivo joint dynamics, and was also the first case in international reports to use in vivo muscle loading ratio data. However, this muscle loading rate could not represent the true physiological load.

[0007] Therefore, the specific expression of the mechanism by which the muscles around the shoulder joint maintain the movement stability of the shoulder joint is not clear at present. More often, the active movement of the shoulder joint is achieved through muscle loading, which is not completely consistent with the biomechanical mechanism by which the muscles around the shoulder joint maintain the humeral head within the glenoid cavity through muscle tension, and further improvement is needed. Summary of the Invention

[0008] The present invention provides a biomechanical experimental device for evaluating the movement stability of the shoulder joint, which is used to study the mechanism of action of the rotator cuff muscles in maintaining the movement stability of the shoulder joint.

[0009] To solve the above problems, the technical solutions provided by the present invention are as follows:

[0010] An embodiment of the present invention provides a biomechanical experimental device for evaluating the movement stability of the shoulder joint, including an industrial robot (1), a customized humerus fixture (2), a scapula fixing gantry (3), a muscle loading wire routing system (4), and a shoulder joint specimen (320). The industrial robot (1) is arranged on one side of the muscle loading wire routing system (4), the scapula fixing gantry (3) is arranged inside the muscle loading wire routing system (4), the scapula of the shoulder joint specimen (320) is mounted and fixed on the scapula fixing gantry (3), and the humerus of the shoulder joint specimen (320) is mounted and fixed at the end of the industrial robot (1) through the customized humerus fixture (2).

[0011] According to an optional embodiment of the present invention, the customized humerus fixture (2) includes a biceps brachii long head - short head muscle wire routing guide plate (201), a customized angle aluminum (202), a tension sensor (203), a pulley mounting seat (204), a V-shaped pulley (205), a humerus fixing sleeve (206), a micro cylinder mounting seat (207), and a micro cylinder (208);

[0012] The customized angle aluminum (202) is fixed to the end of the industrial robot (1) by bolts, and the biceps brachii long head - short head muscle wire routing guide plate (201) is on the customized angle aluminum (202) by bolts; the pulley mounting seat (204) is fixed to the customized angle aluminum (202) by bolts, the V-shaped pulley (205) is fixed to the pulley mounting seat (204) by bolts, two micro cylinder mounting seats (207) are fixed to the customized angle aluminum (202) by threads, and two micro cylinders (208) are fixed to two micro cylinder mounting seats (207) by bolts;

[0013] The humerus fixing sleeve (206) is fixed on the customized angle aluminum (202) by bolts. Screws are screwed inward through the outer ring of the humerus fixing sleeve (206) to fix the humerus in the shoulder joint specimen (320), and the internal and external rotation angles of the humerus fixation are adjusted through the arc guide groove on the customized angle aluminum (202).

[0014] According to an optional embodiment of the present invention, the scapula fixing gantry (3) includes a mounting plate (301), a column (302), an electric push rod bracket (303), an electric push rod (304), a T-shaped fixing seat (305), a rotating shaft (306), a pedestal bearing (307), a T-shaped rotating seat (308), a transition disc (309), a grooved disc (310), a support cylinder (311), a two-link mechanism mounting plate (312), a six-axis force / torque sensor lower mounting plate (313), a six-axis force / torque sensor (314), a six-axis force / torque sensor upper mounting plate (315), a rotating connector (316), a scapula mounting plate (317), a clavicle fixing support rod (318) and a clavicle sleeve (319);

[0015] The mounting plate (301) is fixed on the middle connecting plate of the frame of the muscle loading wire routing system (4) by bolts. The bottom end of the column (302) is fixed on the mounting plate (301) by bolts. The electric push rod bracket (303) is connected to the column (302) by bolts. The upper and lower ends of the electric push rod (304) are connected to the electric push rod bracket (303) by pins. The T-shaped fixing seat (305) is connected to the column (302) by bolts. Both ends of the rotating shaft (306) are supported by the pedestal bearing (307), and the pedestal bearing (307) is connected to the T-shaped fixing seat (305) by bolts. The T-shaped rotating seat (308) is connected to the rotating shaft (306) by a key. The transition disc (309) is connected to the T-shaped rotating seat (308) by bolts. The grooved disc (310) is connected to the transition disc (309) by bolts. The bottom end of the support cylinder (311) is connected to the grooved disc (310) by bolts;

[0016] The two-link mechanism mounting plate (312) is connected to the upper end of the support cylinder (311) by bolts. The six-axis force / torque sensor lower mounting plate (313) is connected to the grooved disc (310) by bolts. The six-axis force / torque sensor (314) is connected to the six-axis force / torque sensor lower mounting plate (313) by bolts. The six-axis force / torque sensor upper mounting plate (315) is connected to the six-axis force / torque sensor (314) by bolts. The rotary connector (316) is connected to the six-axis force / torque sensor upper mounting plate (315) by bolts. The scapula mounting plate (317) is connected to the rotary connector (316) by bolts. The bottom end of the clavicle fixing support rod (318) is connected to the grooved disc (310) by bolts. The left end of the clavicle sleeve (319) is connected to the clavicle fixing support rod (318) by bolts;

[0017] The shoulder joint specimen (320) includes a scapula, a humerus and a clavicle. Among them, the scapula is fixedly connected to the scapula mounting plate (317) by bolts. The humerus is fixed to the end of the industrial robot (1) by the customized humerus fixture (2). The clavicle is inserted into the clavicle sleeve (319), and a screw is screwed inwards on the outer ring of the clavicle sleeve (319) to fix the clavicle.

[0018] According to an optional embodiment of the present invention, the muscle loading wire routing system (4) includes a first fixed pulley (401), a fixed pulley fixing rod (402), a fixed pulley fixing rod mounting plate (403), an aluminum profile (404), a weight (405), an angle iron (406), a bracket (407), a biceps brachii long and short head loading structure (408), a tension sensor (409) and a two-link mechanism (410);

[0019] The fixed pulley fixing rod mounting plate (403) is fixed to the aluminum profile (404) by the angle iron (406). The upper end of the fixed pulley fixing rod (402) is connected to the fixed pulley fixing rod mounting plate (403) by bolts. The first fixed pulley (401) is connected to the fixed pulley fixing rod (402) by bolts. The bracket (407) is composed of the aluminum profile (404) spliced by the angle iron (406) and is used to mount the scapula fixing bench (3). One end of the tension sensor (409) is connected to the tendon, and the other end hangs the weight through the first fixed pulley (401). The bottom end of the two-link mechanism (410) is connected to the two-link mechanism mounting plate (312) by bolts.

[0020] According to an alternative embodiment of the present invention, the two-link mechanism (410) includes a first link (501), a second link (502), and a second fixed pulley (503). The bottom end of the first link (501) is connected to the two-link mechanism mounting plate (312) by bolts. The second link (502) is connected to the first link (501) by bolts. The second fixed pulley (503) is connected to the second link (502) by bolts.

[0021] Beneficial effects: The embodiment of the present invention provides a biomechanical experimental device for evaluating the movement stability of the shoulder joint. The robotic arm is used to drag the humerus to reproduce the specific humerus movement of healthy subjects collected by the motion capture system. Through in vitro shoulder joint movement simulation, the action mechanism of each part of the rotator cuff muscles in maintaining the movement stability of the shoulder joint can be specifically analyzed. The customized humerus fixture designed by the present invention can adjust the position of the humerus clamping and the internal and external rotation angles of the humerus. When using the trajectory optimization algorithm to find the initial optimal industrial robot posture for completing a specific humerus movement, the adjustment of the internal and external rotation angles of the humerus is necessary. The scapula fixing gantry designed by the present invention can adjust the abduction angle and the anterior / posterior tilt angle of the scapula installation. The muscle loading wire routing system designed by the present invention can adjust the position of the fixed pulley by using a two-link mechanism and a chute, etc., so as to adjust the force line direction of the tensile force applied by the suspended weight to be consistent with the physiological direction of the muscle action line. The friction force generated by the present invention using a fixed pulley to adjust the force line direction is smaller. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 It is a schematic structural diagram of a biomechanical experimental device for evaluating the movement stability of the shoulder joint provided by an embodiment of the present application.

[0024] Figure 2 It is a schematic structural diagram of a customized humerus fixture of a biomechanical experimental device for evaluating the movement stability of the shoulder joint provided by an embodiment of the present application.

[0025] Figure 3 It is a side view of a customized humerus fixture of a biomechanical experimental device for evaluating the movement stability of the shoulder joint provided by an embodiment of the present application.

[0026] Figure 4 It is a side view of a scapula fixing gantry of a biomechanical experimental device for evaluating the movement stability of the shoulder joint provided by an embodiment of the present application.

[0027] Figure 5 Front view of the scapula fixing gantry of a biomechanical experimental device for evaluating the kinematic stability of the shoulder joint provided by an embodiment of the present application.

[0028] Figure 6 Partial schematic view of the muscle loading wire routing system of a biomechanical experimental device for evaluating the kinematic stability of the shoulder joint provided by an embodiment of the present application.

[0029] Figure 7 Partial structural schematic view of a customized humeral fixture of a biomechanical experimental device for evaluating the kinematic stability of the shoulder joint provided by an embodiment of the present application.

[0030] Figure 8 Schematic view of the fixing of the weight hanging fixed pulley of a biomechanical experimental device for evaluating the kinematic stability of the shoulder joint provided by an embodiment of the present application.

[0031] Figure 9 Schematic view of the two-link mechanism of a biomechanical experimental device for evaluating the kinematic stability of the shoulder joint provided by an embodiment of the present application. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0033] As Figures 1 to 9 shown, an embodiment of the present invention provides a biomechanical experimental device for evaluating the kinematic stability of the shoulder joint, including an industrial robot 1, a customized humeral fixture 2, a scapula fixing gantry 3, a muscle loading wire routing system 4, and a shoulder joint specimen 320. The industrial robot 1 is arranged on one side of the muscle loading wire routing system 4, and the scapula fixing gantry 3 is arranged inside the muscle loading wire routing system 4. This biomechanical experimental device uses the scapula fixing gantry 3 to fix the scapula, simulates muscle tension by applying gravity to each rotator cuff muscle, the humerus is fixed to the end of the industrial robot 1 through the customized humeral fixture 2, and the industrial robot 1 is used to drag the humerus to reproduce specific humeral movements. The scapula of the shoulder joint specimen 320 is mounted on the scapula fixing gantry 3, and the humerus of the shoulder joint specimen 320 is mounted and fixed to the end of the industrial robot 1 through the customized humeral fixture 2.

[0034] Specifically, as Figure 1 , Figure 2 and Figure 3As shown, the customized humerus fixture 2 includes the biceps brachii long head - short head muscle routing guide plate 201, customized angle aluminum 202, a tension sensor 203, a pulley mounting seat 204, a V - shaped pulley 205, a humerus fixing sleeve 206, a micro - cylinder mounting seat 207, and a micro - cylinder 208.

[0035] The customized angle aluminum 202 is fixed to the end of the industrial robot 1 by bolts, and the biceps brachii long head - short head muscle routing guide plate 201 is on the customized angle aluminum 202 by bolts; the pulley mounting seat 204 is fixed to the customized angle aluminum 202 by bolts, the V - shaped pulley 205 is fixed to the pulley mounting seat 204 by bolts, two micro - cylinder mounting seats 207 are fixed to the customized angle aluminum 202 by threads, and two micro - cylinders 208 are fixed to the two micro - cylinder mounting seats 207 by bolts.

[0036] As Figure 3 shown, the humerus fixing sleeve 206 is fixed to the customized angle aluminum 202 by bolts. The humerus in the shoulder joint specimen 320 is fixed by screwing in screws inward through the outer ring of the humerus fixing sleeve 206, and the internal and external rotation angles of the humerus fixation are adjusted through the arc guide groove on the customized angle aluminum 202.

[0037] As Figure 4 and Figure 5 shown, the scapula fixing gantry 3 includes a mounting plate 301, a column 302, an electric push - rod support 303, an electric push - rod 304, a T - shaped fixing seat 305, a rotating shaft 306, a pedestal bearing 307, a T - shaped rotating seat 308, a transition disc 309, a grooved disc 310, a support cylinder 311, a two - link mechanism mounting plate 312, a six - axis force / torque sensor lower mounting plate 313, a six - axis force / torque sensor 314, a six - axis force / torque sensor upper mounting plate 315, a rotating connector 316, a scapula mounting plate 317, a clavicle fixing support rod 318, and a clavicle sleeve 319.

[0038] The mounting plate 301 is fixed to the middle connecting plate of the frame of the muscle loading routing system 4 by bolts. The bottom end of the column 302 is fixed to the mounting plate 301 by bolts. The electric push - rod support 303 is connected to the column 302 by bolts. The upper and lower ends of the electric push - rod 304 are connected to the electric push - rod support 303 by pins. The T - shaped fixing seat 305 is connected to the column 302 by bolts. Both ends of the rotating shaft 306 are supported by pedestal bearings 307, and the pedestal bearings 307 are connected to the T - shaped fixing seat 305 by bolts. The T - shaped rotating seat 308 is connected to the rotating shaft 306 by a key. The transition disc 309 is connected to the T - shaped rotating seat 308 by bolts. The grooved disc 310 is connected to the transition disc 309 by bolts. The bottom end of the support cylinder 311 is connected to the grooved disc 310 by bolts.

[0039] The two-link mechanism mounting plate 312 is connected to the upper end of the support cylinder 311 by bolts. The lower mounting plate 313 of the six-axis force / torque sensor is connected to the grooved disc 310 by bolts. The six-axis force / torque sensor 314 is connected to the lower mounting plate 313 of the six-axis force / torque sensor by bolts. The upper mounting plate 315 of the six-axis force / torque sensor is connected to the six-axis force / torque sensor 314 by bolts. The rotating connector 316 is connected to the upper mounting plate 315 of the six-axis force / torque sensor by bolts. The scapula mounting plate 317 is connected to the rotating connector 316 by bolts. The bottom end of the clavicle fixing support rod 318 is connected to the grooved disc 310 by bolts. The left end of the clavicle sleeve 319 is connected to the clavicle fixing support rod 318 by bolts.

[0040] The shoulder joint specimen 320 includes the scapula, the humerus, and the clavicle. Among them, the scapula is fixedly connected to the scapula mounting plate 317 by bolts. The humerus is fixed to the end of the industrial robot 1 by the customized humerus fixture 2. The clavicle is inserted into the clavicle sleeve 319, and screws are screwed inwards on the outer ring of the clavicle sleeve 319 to fix the clavicle.

[0041] As Figure 6 shown, the muscle loading wire system 4 includes a first fixed pulley 401, a fixed pulley fixing rod 402, a fixed pulley fixing rod mounting plate 403, an aluminum profile 404, a weight 405, an angle iron 406, a bracket 407, a biceps brachii long and short head loading structure 408, a tension sensor 409, and a two-link mechanism 410.

[0042] The fixed pulley fixing rod mounting plate 403 is fixed to the aluminum profile 404 by the angle iron 406. The upper end of the fixed pulley fixing rod 402 is connected to the fixed pulley fixing rod mounting plate 403 by bolts. The first fixed pulley 401 is connected to the fixed pulley fixing rod 402 by bolts. The bracket 407 is composed of the aluminum profile 404 spliced by the angle iron 406 and is used to mount the scapula fixing bench 3. One end of the tension sensor 409 is connected to the tendon, and the other end hangs the weight through the first fixed pulley 401. The bottom end of the two-link mechanism 410 is connected to the two-link mechanism mounting plate 312 by bolts.

[0043] As Figure 7As shown in the figure, it is a partial schematic diagram of biceps muscle loading. There are functional structures such as a six - dimensional force / torque sensor 314, a biceps brachii long - head - short - head muscle routing guide plate 201, a customized angle aluminum 202, a tension sensor 203, a pulley mounting seat 204, a V - shaped pulley 205, a humerus fixing sleeve 206, a micro - cylinder mounting seat 207, and a micro - cylinder 208 in the biceps muscle loading area. The loading of the biceps brachii long - head and short - head is realized by the micro - cylinder 208, and the action line of muscle loading can be adjusted by adjusting the biceps brachii long - head - short - head muscle routing guide plate 201, the pulley mounting seat 204, and the V - shaped pulley 205, so that the loading direction is consistent with the actual physiological action line direction of the muscle. During the process of the industrial robot 1 dragging the humerus to move, the loading direction of the biceps muscle will move together with the robot. Therefore, the biceps muscle loading system should be fixed at the end of the robotic arm and move with the robot.

[0044] As Figure 8 shown, it is a schematic diagram of a fixed weight - hanging fixed pulley. The fixed weight - hanging fixed pulley includes a first fixed pulley 401, a fixed pulley fixing rod 402, and a fixed pulley fixing rod mounting plate 403. The first fixed pulley 401 is connected to the fixed pulley fixing rod 402 by bolts, and the fixed pulley fixing rod 402 is connected to the fixed pulley fixing rod mounting plate 403 by threads.

[0045] As Figure 9 shown, the two - link mechanism 410 includes a first link 501, a second link 502, and a second fixed pulley 503. The bottom end of the first link 501 is connected to the two - link mechanism mounting plate 312 by bolts, the second link 502 is connected to the first link 501 by bolts, and the second fixed pulley 503 is connected to the second link 502 by bolts.

[0046] The shoulder joint specimen 320 is fixed at the end of the industrial robot 1 through a customized humerus fixture 2. By calibrating the rotation center of the humeral head in the shoulder joint specimen 320 and the coordinate system at the end of the industrial robot 1, the rigid - body relationship between the shoulder joint specimen 320 and the end of the robotic arm 1 can be established. By optimizing the humerus motion data collected by the motion capture system and then programming the humerus motion data into the industrial robot 1 using the trajectory optimization algorithm, it is possible to use the industrial robot 1 to drag the humerus to reproduce the specific humerus motion collected by the motion capture system, enabling multi - degree - of - freedom humerus motion, which is closer to the real humerus motion compared to other extracorporeal shoulder joint motion simulation devices.

[0047] Figure 3 Combined Figure 1 and Figure 2, the fixation between the shoulder joint specimen 320 and the humerus fixing sleeve 406 is achieved by screwing a screw inward on the outer ring of the humerus fixing sleeve 406 to fix the humerus. The humerus fixing sleeve 406 is fixed to the customized angle aluminum 402 by bolt connection, and the internal and external rotation angles of the humerus fixation can be adjusted through the arc guide groove on the customized angle aluminum 402. When the trajectory optimization algorithm is searching for the initial optimal industrial robot posture to complete a specific humerus movement, the adjustment of the internal and external rotation angles of the humerus is necessary. Therefore, the adjustable internal and external rotation angles of the humerus will allow the internal and external rotation angles of the humerus to be adjusted to the initial humerus posture for completing a specific humerus movement within a short time, thereby improving the experimental efficiency.

[0048] As Figure 4 shown, the T-shaped rotating seat 308 is connected to the rotating shaft 306 by a key connection, and the rotating shaft 306 is supported by a pedestal bearing 307. Therefore, the T-shaped rotating seat 308 can rotate around the rotating shaft 306. By controlling the extension and retraction of the electric push rod 304, the rotation of the scapula in the vertical plane can be realized, so the scapulohumeral rhythm can be simulated. By rotating the bottom end of the clavicle fixing support rod 318 or moving and rotating the installation position of the clavicle sleeve 319 on the clavicle fixing support rod 318, the fixing position of the clavicle can be adjusted. By adjusting the fixing angle of the bolt connection between the scapula mounting plate 317 and the rotating connector 316, the abduction angle of the scapula mounting can be adjusted. As Figure 5 shown, as shown in the front view of the scapula fixing bench, by rotating and adjusting the fixing position of the rotating connector 316, the anterior / posterior tilt angle of the scapula mounting can be adjusted.

[0049] As Figure 6 shown, the muscle loading wire system 4 applies tensile force to each part of the rotator cuff muscles by hanging weights to simulate muscle tension, and different combinations of muscle tension can be simulated by hanging weights of different weights. The tendon of each muscle is sutured with a surgical suture and connected to one end of the force sensor 409, and the other end of the force sensor 409 is connected to a hanging weight through a fixed pulley. As Figure 7 shown, a partial schematic diagram of the biceps brachii muscle loading. The loading of the long head and short head of the biceps brachii is realized by a micro cylinder 208, and the action line of the muscle loading can be adjusted by adjusting the muscle wire guiding plates 201, pulley mounting seats 204 and V-shaped pulleys 205 of the long head and short head of the biceps brachii, so that the loading direction is consistent with the actual physiological direction of the muscle. During the process of the industrial robot 1 dragging the humerus to move, the loading direction of the biceps brachii will move with the robot. Therefore, it is necessary to fix the loading system of the biceps brachii at the end of the robotic arm to move with the robot. As Figure 8As shown in the schematic diagram of the fixed heavy object hanging on the fixed pulley, the position of the first fixed pulley 401 can be adjusted by adjusting its movement on the fixed pulley fixing rod 402; rotating the upper end of the fixed pulley fixing rod 402; and adjusting the movement of the fixed pulley fixing rod 402 in the chute of the fixed pulley fixing rod mounting plate 403.

[0050] The position of the second fixed pulley 503 can be adjusted by rotating the bottom end of the first connecting rod 501; rotating the second connecting rod 502; and moving the second fixed pulley 503. By adjusting the positions of the first fixed pulley 401 and the second fixed pulley 503, the direction of the force line of the pulling force exerted on the hanging heavy object can be adjusted to be consistent with the physiological direction of the muscle action line. Compared with other external shoulder joint movement simulation devices that use a baffle to adjust the force line direction, using a fixed pulley to adjust the force line direction produces less frictional force.

[0051] The embodiment of the present invention provides a biomechanical experimental device for evaluating the movement stability of the shoulder joint, which is used to study the mechanism of action of the rotator cuff muscles in maintaining the movement stability of the shoulder joint. The invention uses the robotic arm of an industrial robot to drag the humerus to reproduce the specific movement of the humerus captured by motion capture, and can reproduce the multi-degree-of-freedom movement of the humerus, which is closer to the real humerus movement compared with other external shoulder joint movement simulation devices. The customized humerus fixture designed by the invention can, on the basis of realizing the fixation of the humerus, also realize the adjustment of the clamping position of the humerus and the internal / external rotation angle of the humerus. When using the trajectory optimization algorithm to find the initial optimal posture of the industrial robot to complete a specific humerus movement, the adjustment of the internal / external rotation angle of the humerus is necessary. The designed scapula fixing gantry of the invention can adjust the abduction angle and the anterior / posterior tilt angle of the scapula installation. The designed muscle loading wire routing system of the invention can adjust the orientation and height of the fixed pulley through a two-link mechanism and a fixed pulley fixing rod, so that the direction of the initial muscle tension exerted by hanging a heavy object is consistent with the physiological direction of the muscle action line, and can simulate the direction of muscle force, being closer to the in-vivo conditions of muscle force application.

[0052] The above is only the specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be covered within the protection scope of the present invention; those of ordinary skill in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention is subject to the scope defined by the claims.

Claims

1. A biomechanical experimental device for evaluating the motion stability of the shoulder joint, characterized in that It includes an industrial robot (1), a customized humerus fixture (2), a scapula fixing bench (3), a muscle loading wire routing system (4), and a shoulder joint specimen (320). The industrial robot (1) is arranged on one side of the muscle loading wire routing system (4), and the scapula fixing bench (3) is arranged inside the muscle loading wire routing system (4). The scapula of the shoulder joint specimen (320) is mounted and fixed on the scapula fixing bench (3), and the humerus of the shoulder joint specimen (320) is mounted and fixed at the end of the industrial robot (1) through the customized humerus fixture (2).

2. The biomechanical experimental device for evaluating the movement stability of the shoulder joint according to claim 1, wherein The customized humerus fixture (2) includes a biceps brachii long head - short head muscle wire routing guide plate (201), a customized angle aluminum (202), a tensile sensor (203), a pulley mounting seat (204), a V-shaped pulley (205), a humerus fixing sleeve (206), a micro cylinder mounting seat (207), and a micro cylinder (208); The customized angle aluminum (202) is fixed to the end of the industrial robot (1) by bolts, and the biceps brachii long head - short head muscle wire routing guide plate (201) is fixed to the customized angle aluminum (202) by bolts; the pulley mounting seat (204) is fixed to the customized angle aluminum (202) by bolts, the V-shaped pulley (205) is fixed to the pulley mounting seat (204) by bolts, two of the micro cylinder mounting seats (207) are fixed to the customized angle aluminum (202) by threads, and two of the micro cylinders (208) are fixed to two of the micro cylinder mounting seats (207) by bolts; The humerus fixing sleeve (206) is fixed to the customized angle aluminum (202) by bolts. Screws are screwed inwards through the outer ring of the humerus fixing sleeve (206) to fix the humerus in the shoulder joint specimen (320), and the internal and external rotation angles of the humerus fixation are adjusted through the arc guide groove on the customized angle aluminum (202).

3. The biomechanical experimental device for evaluating the movement stability of the shoulder joint according to claim 2, characterized in that, The scapula fixing bench (3) includes a mounting plate (301), a column (302), an electric push rod support (303), an electric push rod (304), a T-shaped fixing seat (305), a rotating shaft (306), a pedestal bearing (307), a T-shaped rotating seat (308), a transition disc (309), a grooved disc (310), a support cylinder (311), a two-link mechanism mounting plate (312), a six-axis force / torque sensor lower mounting plate (313), a six-axis force / torque sensor (314), a six-axis force / torque sensor upper mounting plate (315), a rotating connector (316), a scapula mounting plate (317), a clavicle fixing support rod (318), and a clavicle sleeve (319); The installation plate (301) is fixed to the middle connecting plate of the frame of the muscle loading wire system (4) by bolts. The bottom end of the upright column (302) is fixed to the installation plate (301) by bolts. The electric push rod bracket (303) is connected to the upright column (302) by bolts. The upper and lower ends of the electric push rod (304) are connected to the electric push rod bracket (303) by pins. The T-shaped fixing seat (305) is connected to the upright column (302) by bolts. Both ends of the rotating shaft (306) are supported by the pedestal bearings (307). The pedestal bearings (307) are connected to the T-shaped fixing seat (305) by bolts. The T-shaped rotating seat (308) is connected to the rotating shaft (306) by a key. The transition disc (309) is connected to the T-shaped rotating seat (308) by bolts. The grooved disc (310) is connected to the transition disc (309) by bolts. The bottom end of the support cylinder (311) is connected to the grooved disc (310) by bolts. The two-link mechanism installation plate (312) is connected to the upper end of the support cylinder (311) by bolts. The six-axis force / torque sensor lower installation plate (313) is connected to the grooved disc (310) by bolts. The six-axis force / torque sensor (314) is connected to the six-axis force / torque sensor lower installation plate (313) by bolts. The six-axis force / torque sensor upper installation plate (315) is connected to the six-axis force / torque sensor (314) by bolts. The rotating connector (316) is connected to the six-axis force / torque sensor upper installation plate (315) by bolts. The scapula installation plate (317) is connected to the rotating connector (316) by bolts. The bottom end of the clavicle fixing support rod (318) is connected to the grooved disc (310) by bolts. The left end of the clavicle sleeve (319) is connected to the clavicle fixing support rod (318) by bolts. The shoulder joint specimen (320) includes a scapula, a humerus and a clavicle. Among them, the scapula is fixed to the scapula installation plate (317) by bolts. The humerus is fixed to the end of the industrial robot (1) by the customized humerus fixture (2). The clavicle is inserted into the clavicle sleeve (319), and a screw is screwed inwards on the outer ring of the clavicle sleeve (319) to fix the clavicle.

4. The biomechanical experimental device for evaluating the motion stability of the shoulder joint according to claim 3, characterized in that, The muscle loading wire system (4) includes a first fixed pulley (401), a fixed pulley fixing rod (402), a fixed pulley fixing rod installation plate (403), an aluminum profile (404), a weight (405), an angle iron (406), a bracket (407), a biceps brachii long and short head loading structure (408), a tension sensor (409) and a two-link mechanism (410). The fixed pulley fixed rod mounting plate (403) is fixed on the aluminum profile (404) through an angle iron (406). The upper end of the fixed pulley fixed rod (402) is connected to the fixed pulley fixed rod mounting plate (403) by bolts. The first fixed pulley (401) is connected to the fixed pulley fixed rod (402) by bolts. The bracket (407) is composed of aluminum profiles (404) spliced through the angle iron (406) and is used to mount the scapula fixing gantry (3). One end of the tension sensor (409) is connected to the tendon, and the other end hangs a heavy object through the first fixed pulley (401). The bottom end of the two-link mechanism (410) is connected to the two-link mechanism mounting plate (312) by bolts.

5. The biomechanical experimental device for evaluating the movement stability of the shoulder joint according to claim 4, wherein, The two-link mechanism (410) includes a first link (501), a second link (502), and a second fixed pulley (503). The bottom end of the first link (501) is connected to the two-link mechanism mounting plate (312) by bolts. The second link (502) is connected to the first link (501) by bolts. The second fixed pulley (503) is connected to the second link (502) by bolts.

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