Rigidity-variable multi-degree-of-freedom upper limb rehabilitation device

Abstract

The invention relates to the technical field of medical instruments, in particular to a variable-stiffness multi-degree-of-freedom upper limb rehabilitation device which comprises a base, a plurality of driving motors are arranged on the base, driving shafts of the driving motors are connected with driving arms, the other ends of the driving arms are hinged to driven arms, and the lengths of the driven arms can be adjusted; a variable-stiffness module is fixedly nested in each driven arm and is driven by a variable-stiffness motor, the other end of each driven arm is hinged to a working platform, a handle driven by a handle motor is arranged on the working platform so as to enable the handle to rotate, and an arm support is arranged on one side of the handle; and the driving motor, the variable stiffness motor and the handle motor are electrically connected with the man-machine interaction platform. The rigidity of the variable rigidity module is changed to influence the rigidity of the whole device, and the wide rigidity interval of the device can adapt to various rehabilitation modes and different rehabilitation stages; the hand is fixed, the forearm is fixed through the arm support, then the device is controlled to operate, and rehabilitation of shoulders, elbows and wrists in multiple dimensions can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of medical device technology, specifically to a multi-degree-of-freedom upper limb rehabilitation device equipped with a variable stiffness module. Specifically, the device utilizes a three-degree-of-freedom parallel mechanism and other components to achieve precise and efficient training for patients with upper limb motor dysfunction, while addressing the shortcomings of existing upper limb rehabilitation devices in terms of cost, portability, ease of use, and stiffness adaptability. Background Art

[0002] With the advancement of modern medical technology and the increasing demand for healthy living, effective rehabilitation treatment has become increasingly important for patients with impaired upper limb motor function due to various injuries. As a key part of the human body for completing numerous fine motor movements and daily activities, the loss or limitation of upper limb motor function can have a significant negative impact on patients' ability to care for themselves and their quality of life.

[0003] Currently, commonly used upper limb rehabilitation methods in clinical practice primarily include traditional manual-assisted rehabilitation training and training using rehabilitation equipment. Traditional manual-assisted training relies on one-on-one assistance from rehabilitation therapists to help patients with passive joint movements, assisted or resisted exercises, and other tasks. While this approach allows for more precise control of training intensity and range of motion based on real-time patient feedback, it suffers from inefficiencies, high labor costs, and the difficulty in ensuring long-term, frequent training. This significantly limits the effectiveness of rehabilitation and the scope of patients it can address.

[0004] While existing upper limb rehabilitation devices are available in a variety of styles, such as simple range of motion trainers and suspension training devices, they generally suffer from limited functionality and limited flexibility and diversity in movement patterns. Most devices only target specific joints or achieve simple, fixed motion trajectories, failing to simulate the complex multi-degree-of-freedom movements of the human upper limb in its natural state. This makes them unable to meet the personalized rehabilitation training needs of different patients, who vary in injury severity and recovery stage.

[0005] In addition, although some high-end rehabilitation robots have certain multi-degree-of-freedom movement capabilities, they are often complex in structure, too expensive, and not easy to carry. They are not easy to promote and popularize in primary medical institutions and families, making it difficult for many patients to obtain appropriate and effective rehabilitation treatment resources.

[0006] By rationally utilizing the structural characteristics of multi-degree-of-freedom parallel mechanisms and variable stiffness modules, it is hoped that a cost-effective upper limb rehabilitation device can be developed that can address the shortcomings of existing rehabilitation methods, align with the biomechanical characteristics of the human upper limb, and provide a cost-effective solution, thereby reducing the cost of upper limb rehabilitation treatment and improving its efficiency. In this context, this invention, with its unique kinematic characteristics and modular structural design, offers advantages such as portability, affordability, wide applicability, and home use, providing a new approach and solution for upper limb rehabilitation training. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention provides an upper limb rehabilitation device with variable stiffness and multiple degrees of freedom.

[0008] The purpose of the present invention is to be achieved by adopting the following technical solutions. A variable stiffness multi-degree-of-freedom upper limb rehabilitation device proposed in accordance with the present invention includes a base, a plurality of drive motors are arranged on the base, the drive shafts of the drive motors are all connected to the active arm, the other end of the active arm is hinged to the driven arm, the length of the driven arm can be adjusted, a variable stiffness module is fixed and nested in the driven arm, the variable stiffness module is driven by the variable stiffness motor, the other end of the driven arm is hinged to the working platform, a handle driven by the handle motor is arranged on the working platform, and an arm support is arranged on one side of the handle; the drive motor, the variable stiffness motor, and the handle motor are electrically connected to the human-computer interaction platform.

[0009] Furthermore, the overall shape of the base is an equilateral triangle, and the drive motor is arranged at the vertex of the equilateral triangle; the base includes a motor fixing base located at the vertex of the equilateral triangle, a double-convex connecting rod and a concave-convex connecting rod connecting the two motor fixing bases, the side wall of the motor fixing base is provided with two extension arms with an angle of 60°, the end face of the extension arm is provided with a groove, both ends of the double-convex connecting rod are provided with a boss, one end of the concave-convex connecting rod is provided with a boss, and the other end is provided with a groove; the boss at one end of the double-convex connecting rod is inserted into the groove of the extension arm on the motor fixing base, and the boss at the other end is inserted into the groove of the end of the concave-convex connecting rod, and the boss at the other end of the concave-convex connecting rod is inserted into the groove of the extension arm on the other motor fixing base, and a locking piece is used to pass through the joint between the motor fixing base and the double-convex connecting rod, the joint between the motor fixing base and the concave-convex connecting rod, and the joint between the double-convex connecting rod and the concave-convex connecting rod to realize the fixed setting of the base, and the drive motor is arranged on the motor fixing base.

[0010] Furthermore, the active arm includes a type I connector, an active rod, and a type II connector I. The type I connector is connected to the drive shaft of the drive motor. The side walls of the type I connector and the type II connector I are provided with protrusions, and the end faces of the protrusions are provided with grooves. Both ends of the active rod are provided with bosses, and the bosses at both ends are respectively inserted into the grooves of the type I connector and the grooves of the type II connector I, and then a locking piece is used to connect the type I connector, the active rod, and the type II connector I into an active arm.

[0011] Furthermore, the active arm is hinged to the driven arm through a rotating shaft, and the rotating shaft includes a long round nut and a thumb screw. The long round nut passes through the through hole of the active arm and the through hole of the driven arm, and both ends of the long round nut are threadedly connected to the thumb screw.

[0012] Furthermore, the driven arm includes a type II connector II, a length gear column, a variable stiffness module, a long rod shell, a short rod shell, and a type II connector III. The type II connector II is hinged to the active arm, and a groove is provided on the raised end face of the side wall of the type II connector II. One end of the long rod shell is provided with a boss, and the boss of the long rod shell is inserted into the groove of the type II connector II, and a locking piece is used to fix the joint of the type II connector II and the long rod shell. The other end of the long rod shell is open, and the length gear column is slidably inserted into the opening of the long rod shell. A plurality of holes are arranged axially on the length gear column, and a through hole is provided on the side wall of the long rod shell. , a locking piece is used to pass through the through hole on the long rod shell and one of the holes on the length gear column to achieve length adjustment and fixation, and a slider is set at the end of the length gear column; an opening is set at one end of the short rod shell, and the length gear column is slidably passed through the opening of the short rod shell, and the slider is fixedly connected to the variable stiffness module in the short rod shell, and a boss is provided on the other end face of the short rod shell, and the side wall of the type II connector III is provided with a protrusion with a groove on the end face, and the boss on the short rod shell is inserted into the groove of the type II connector III, and a locking piece is used to pass through the joint between the short rod shell and the type II connector III to achieve fixed connection.

[0013] Furthermore, the variable stiffness module includes a micro motor, an elastic rope, a force block, and a pulley. The micro motor is fixed in a short rod housing, the rotating shaft of the micro motor is connected to the gear set, a rotating column is provided on the output gear of the gear set, a through hole is provided on the rotating column, the force block is fixedly connected to the slider, a through hole is provided on the force block, pulleys are provided on the inner walls of the short rod housing on both sides of the force block, the shafts of the pulleys are fixed on the inner wall of the short rod housing, the elastic rope is arranged in a closed loop, and the elastic rope passes through the through hole on the rotating column, bypasses the pulley on one side, passes through the through hole on the force block, and bypasses the pulley on the other side in sequence.

[0014] Furthermore, a cover plate is provided on the wall of the short rod housing, and the cover plate is located at a position corresponding to the micro motor.

[0015] Furthermore, the working platform includes a base, a shell, a bearing, a handle, a palm fixing device, a gear set, a handle motor, and an arm support. The shell is arranged on the base. The shell and the handle are both annular bodies. The bearing is nested in the inner wall of the shell, and the handle is nested in the inner wall of the bearing. A column for easy handholding is passed through the middle cavity of the handle. The palm fixing device is rotatably arranged on the edge of the handle, and the palm fixing device is in the shape of a swing arm; a large gear is sleeved on the handle, and a small gear meshing with the large gear is rotatably arranged on the shell. The large gear and the small gear form a gear set, and a handle motor fixedly connected to the small gear is fixed on the shell.

[0016] Furthermore, an arm rest is provided on the base. After the palm is placed in the handle, the arm can be placed on the arm rest. The arm rest includes a slide groove, an arm rest base plate, and a slide belt. The arm rest base plate is fixed on the base, and the slide groove is fixed on the arm rest base plate. A semicircular groove is provided on the upper part of the slide groove, and a slide belt is slidably provided in the semicircular groove. The slide belt is a semicircular plate-shaped body, and the outer wall of the slide belt slides and fits with the inner wall of the slide groove and can be fixed.

[0017] Furthermore, the palm fixing device includes a hand clamping block, a double-hole connecting rod, a slot active connecting rod, a double rotating shaft, a rotating key, a spring, and a chuck. The hand clamping block is in the shape of a swing arm, and a double rotating shaft is fixedly provided at one end of the hand clamping block. The double rotating shaft includes two relatively fixed rotating shafts, and the double-hole connecting rod and the slot active connecting rod are rotatably connected to the two rotating shafts of the double rotating shafts respectively. The double-hole connecting rod is rotatably set on the handle, and the other end of the slot active connecting rod is provided with a limiting protrusion facing the side of the handle, and a rotating key is provided on the side away from the handle. The rotating key is provided with an annular protrusion and a handle at the end. The part between the annular protrusion of the rotating key and the handle is slid through the chuck, and the chuck is fixed on the handle. An elastic member is sleeved on the rotating key between the annular protrusion and the chuck, and the handle is provided with a groove corresponding to the limiting protrusion on the slot active connecting rod. Under the action of the elastic member, the limiting protrusion is inserted into the groove and rests on the bottom surface of the groove.

[0018] Compared with the prior art, the present invention is beneficial in that:

[0019] The present invention discloses a multi-degree-of-freedom modular upper limb rehabilitation device equipped with a variable stiffness module, which is suitable for upper limb rehabilitation for patients with neurological diseases such as stroke and cerebral palsy, patients with musculoskeletal diseases such as frozen shoulder and elbow adhesions, and elderly people with upper limb dysfunction. When in use, first hold the handle with your hand, and the palm fixing device fixes the position of the wearer's palm. The human-computer interaction platform reads pre-recorded clinical assessment data, calculates and sets the hand movement trajectory and wrist posture suitable for the patient, and sends the motion control data to the motor respectively, so that each motor rotates based on the control instruction, thereby driving the working platform to generate two-degree-of-freedom translational motion in the plane and flexion and extension rotation around the wrist. The handle motor drives the handle to generate internal and external rotation motion of the wrist to complete the rehabilitation exercise training of the upper limb. The variable stiffness module affects the stiffness of the entire device by changing its own stiffness. The wide stiffness range of the device can adapt to a variety of rehabilitation modes and different rehabilitation stages, improve the flexibility of the rehabilitation device, and achieve more natural human-computer interaction.

[0020] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, which can be implemented in accordance with the contents of the specification, and to make the objects, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 1. It is a top view of an embodiment of an upper limb rehabilitation device with variable stiffness and multiple degrees of freedom according to the present invention;

[0022] Figure 2 yes Figure 1 Schematic diagram of the decomposition;

[0023] Figure 3 yes Figure 1 Exploded diagram of the active arm, driven arm and rotating shaft;

[0024] Figure 4 yes Figure 1 Exploded view of the active boom

[0025] Figure 5 yes Figure 1 Exploded view of the middle follower arm;

[0026] Figure 6 yes Figure 5 Schematic diagram of the variable stiffness module mounted in the follower arm;

[0027] Figure 7 yes Figure 1 Schematic diagram of the working platform;

[0028] Figure 8 yes Figure 1 Exploded view of the working platform;

[0029] Figure 9 yes Figure 8 Schematic diagram of the mid-palm fixation device;

[0030] Figure 10 for Figure 8 Schematic diagram of the mid-palm fixation device from another perspective;

[0031] Figure 11 yes Figure 8 Exploded view of the middle arm support;

[0032] Figure 12 Schematic diagram of an application scenario of an embodiment of a variable stiffness multi-degree-of-freedom upper limb rehabilitation device of the present invention;

[0033] Figure 13 Schematic diagram of the principle of the variable stiffness module in an embodiment of the present invention.

[0034] Reference numerals:

[0035] 1-base, 11-motor fixing seat, 12-double convex connecting rod, 13-concave-convex connecting rod;

[0036] 111- extension arm;

[0037] 2- drive motor;

[0038] 3-active arm, 31-type I connector, 32-active rod, 33-type II connector I;

[0039] 4- driven arm, 41- type II connector II, 42- length shift column, 43- variable stiffness module, 44- long rod housing, 45- short rod housing, 46- cover plate, 47- limit pin, 48- type II connector III;

[0040] 421-slider;

[0041] 431- micro motor, 432- elastic rope, 433- force block, 434- pulley;

[0042] 5-working platform, 51-base, 52-housing, 53-bearing, 54-handle, 55-palm fixing device, 56-gear set, 57-front panel, 58-stepping motor, 59-arm support;

[0043] 551-hand block, 552-double-hole connecting rod, 553-slot active connecting rod, 554-double rotating shaft, 555-rotating key, 556-spring, 557-half-thread bolt, 558-chuck;

[0044] 591-slideway, 592-arm support base plate, 593-connecting screw, 594-limiting screw, 595-slide belt;

[0045] 6-rotating shaft, 61-round long nut, 62-thumbnail screw. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] An embodiment of the variable stiffness multi-degree-of-freedom upper limb rehabilitation device of the present invention is as follows: Figures 1 to 11 As shown, the device of the present invention is based on a multi-degree-of-freedom parallel mechanism, and the device includes a base 1, a drive motor 2, an active arm 3, a driven arm 4, a working platform 5, and a rotating shaft 6.

[0048] The base 1 includes a motor mounting base 11, a double-convex connecting rod 12, and a male-concave connecting rod 13. In this embodiment, the base 1 is an equilateral triangle, with the motor mounting bases 11 located at the three vertices of the equilateral triangle. The distance from the center of one motor base (i.e., the vertex of the equilateral triangle) to the center of another motor base is 600 mm.

[0049] The sidewalls of the motor mount 11 are provided with two extension arms 111, with an angle of 60° between them. The end surfaces of the extension arms 111 are provided with grooves. A double-convex connecting rod 12 has bosses at both ends, while a concave-convex connecting rod 13 has a boss at one end and a groove at the other. The boss at one end of the double-convex connecting rod 12 fits into the groove of the extension arm 111 on the motor mount 11, while the boss at the other end fits into the groove at the end of the concave-convex connecting rod 13. The boss at the other end of the concave-convex connecting rod 13 fits into the groove of the extension arm 111 on another motor mount 11. The double-convex connecting rod 12 and the concave-convex connecting rod 12 are used to position the three motor mounts 11. Screws or pins are inserted through the joints between the motor mount 11 and the double-convex connecting rod 12, the joints between the motor mount 11 and the concave-convex connecting rod 13, and the joints between the double-convex connecting rod 12 and the concave-convex connecting rod 13 to secure the base 1.

[0050] The driving motor 2 is arranged on the motor fixing seat 11 .

[0051] The active arm 3 includes a type I connector 31, an active rod 32, and a type II connector I 33. The type I connector 31 is connected to the drive shaft of the drive motor 2, and is used to drive the active arm 3 to rotate or swing. The side wall of the type I connector 31 is provided with a protrusion, and the end face of the protrusion is provided with a groove. The side wall of the type II connector I 33 is provided with a protrusion, and the end face of the protrusion is provided with a groove. Bosses are provided at both ends of the active rod 32, and the bosses at both ends are respectively inserted into the grooves of the type I connector 31 and the grooves of the type II connector I 33, and then screws or pins are used to connect the type I connector 31, the active rod 32, and the type II connector I 33 to form the active arm 3. In this embodiment, the working length of the active arm is 250 mm.

[0052] The Type II connector I 33 is hinged to the driven arm 4 via a rotating shaft 6. The rotating shaft includes a long circular nut 61 and a thumb screw 62. The long circular nut 61 is inserted into a through hole in the Type II connector I 33 and a through hole in the Type II connector II 41 on the driven arm 4. The thumb screws 62 are threaded onto the ends of the long circular nut 61 to prevent the long circular nut 61 from falling off and to prevent it from clamping the Type II connector I 33 and Type II 41, allowing the Type II connectors I 33 and II 41 to rotate relative to each other.

[0053] The driven arm 4 includes a Type II connector II 41, a length shift column 42, a variable stiffness module 43, a long rod housing 44, a short rod housing 45, a cover plate 46, a limit pin 47, and a Type II connector III 48. The Type II connector II 41 is hinged to the active arm 3. The raised end surface of the side wall of the Type II connector II 41 is provided with a groove. One end of the long rod housing 44 is provided with a boss that fits into the groove. A limit pin 47 passes through the junction of the Type II connector II 41 and the long rod housing 44 to achieve a fixed connection between the Type II connector II 41 and the long rod housing 44. The other end of the long rod housing 44 is open, and the length shift column 42 slides through the opening of the long rod housing 44, allowing the length shift column 42 to enter the long rod housing 44. The length shift column 42 is cylindrical in shape, with multiple holes arranged axially along the cylinder. The sidewall of the long rod housing 44 is provided with a through-hole. When the length shift column 42 slides to a certain position within the long rod housing 44, one of the holes on the cylinder aligns with the through-hole in the long rod housing 44. A stop pin 47 then passes through the through-hole and the hole in the length shift column 42, achieving adjustment and fixation of the length shift column 42. A slider 421 is provided at the end of the length shift column 42. An opening is provided at one end of the short rod housing 45. The length shift column 42 slides through the opening in the short rod housing 45, and the slider 421 slides within the short rod housing 45. A boss is provided on the other end of the short rod housing 45. A protrusion is provided on the sidewall of the Type II connector III 48, and a groove is provided on the end face of the protrusion. The boss on the short rod housing 45 fits into the groove. A stop pin 47 is provided at the junction between the short rod housing 45 and the Type II connector III 48 to achieve fixation. In this embodiment, the distance between the centers of the two II-type connectors of the driven arm 4 is 250 mm to 292 mm, that is, the length of the driven arm 4 varies within a range of 42 mm.

[0054] The main cross-section dimensions of the active arm 3 and the passive arm 4 are both 20mm by 15mm. The circular portion of both connectors (including Type I and Type II connectors) has a diameter of 35mm. The bosses on the active and passive arms 3 (including those on the active rod 32, the long rod housing 44, and the short rod housing 45) are all 10mm in length, width, and height. The grooves in the connectors (including Type I and Type II connectors) are 10.05mm in length, width, and depth.

[0055] A variable stiffness module 43 is disposed within the short rod housing 45 and comprises a micromotor 431, an elastic cord 432, a force block 433, and a pulley 434. The micromotor 431 is secured within the short rod housing 45, its rotating shaft connected to a gear train. A rotating column with a through hole is disposed on the output gear of the gear train. The force block 433 is fixedly connected to the slider 421 via screws or bolts and can slide with the slider 421. The force block 433 is provided with a through hole. Pulleys 434 are disposed on the inner wall of the short rod housing 45 on either side of the force block 433, with their shafts fixed to the inner wall of the short rod housing 45. The elastic cord 432 is arranged in a closed loop, passing through the through hole in the rotating column, around one pulley 434, through the through hole in the force block 433, and around the other pulley 434. In this embodiment, a cover plate 46 is provided on the wall of the short rod housing 45 , and the cover plate 46 faces the micro motor 431 . After opening the cover plate 46 , the micro motor 431 and other components connected to the micro motor 431 can be checked or repaired.

[0056] In this embodiment, the elastic cord 432 is made of nylon 66. In the variable stiffness module 43, the rotation of the rotating column on the micromotor 431 can twist or untwist the closed-loop elastic cord 432, thereby controlling the stretching or relaxation of the elastic cord 432, which directly affects the module's stiffness. When the elastic cord 432 is stretched, the stiffness of the variable stiffness module 43 increases; conversely, when the elastic cord 432 is relaxed, the stiffness decreases. This adjustability allows the variable stiffness module 43 to dynamically adjust the stiffness of the entire device according to demand. The variable stiffness module 43 not only affects its own stiffness but also influences the stiffness of the entire device through its connection and coordination with other components. In a multi-degree-of-freedom parallel mechanism, the stiffness of the variable stiffness module 43 is positively correlated with the stiffness of the entire device. The specific mathematical model is as follows.

[0057] The stiffness calculation of the variable stiffness module 43 is as follows: Figure 13 As shown, d is the distance between the two pulleys 434, and x is the input force F applied to the force block 433 in the variable stiffness module 43. in The displacement that occurs when c is the tension on the elastic cord 432, F out is the equivalent output force applied by the variable stiffness module to the outside, which is equal to F in Equal, according to Figure 13 get:

[0058]

[0059] Among them F in is the restoring force of the variable stiffness module 43 (i.e. Figure 13 The input force F received by the medium variable stiffness module 43 in ), the above formula is:

[0060]

[0061] Among them, k 绳 for Figure 13 k in c , that is, the stiffness of the elastic rope 432.

[0062] Solve for the stiffness k of the variable stiffness module 43 mod (Right now Figure 13 The expression of k) in is:

[0063]

[0064] For the entire installation:

[0065] K1 is the stiffness matrix of the parallel mechanism branch chain, which can be expressed as:

[0066]

[0067] where k i is the stiffness on the i-th branch.

[0068] The static stiffness matrix of the parallel mechanism is:

[0069] K=J T K1J

[0070] By solving the Jacobian matrix of the multi-degree-of-freedom mechanism, the static stiffness matrix of the parallel mechanism can be obtained. It can be seen that the stiffness of the variable stiffness module 43 is positively correlated with the stiffness of the device, and changes with the posture change of the parallel mechanism. By adjusting the stiffness of the variable stiffness module 43, the overall stiffness of the device can be controlled. When the patient's movements are abnormal or uncooperative, the robot stiffness is reduced to avoid excessive pulling or collision; the device stiffness is adjusted in real time according to the patient's activeness to stimulate their autonomous participation. In the early rehabilitation process, it is set to low stiffness mode, which is mainly used for passive training and muscle tension regulation; in the middle and late rehabilitation, the device stiffness is gradually increased to achieve semi-active or active training and enhance muscle strength and coordination.

[0071] The Type II connectors III48 at the ends of the three follower arms 4 are set on the working platform 5. The distance between the centers of the three circular holes on the working platform 5 that are concentric with the circular holes on the Type II connector III48 is 150 mm. The diameters of the above two circular holes (the circular holes on the Type II connector III48 and the circular holes on the working platform 5) are both 10.05 mm. The circular holes on the Type II connector III48 and the circular holes on the working platform 5 are superimposed on each other, and the two circular holes are inserted with long circular nuts. The outer diameter of the long circular nuts is 10 mm, the length is 30 mm, and the screw hole size is M5. A large head screw with a head diameter of 16 mm and a screw data of M5*8 is screwed into each end of the long circular nut, thereby realizing the hinged connection between the Type II connector III48 and the working platform 5. The long circular nut acts as a rotating shaft, and the large head screw prevents the nut from falling off.

[0072] The work platform 5 includes a base 51, a housing 52, a bearing 53, a handle 54, a palm fixing device 55, a gear set 56, a front panel 57, a stepper motor 58, and an armrest 59. The housing 52 is mounted on the base 51. The housing 52 is an annular body with a bearing 53 embedded in its inner wall. The handle 54 is also embedded in the inner wall of the bearing 53. The handle 54 is an annular body with a central cavity provided with a column for easy gripping. The edge of the handle 54 is provided with a palm fixing device 55. The palm fixing device 55 is in the shape of a swing arm and is rotatably mounted on the handle 54. After rotating to a certain angle, the palm fixing device 55 can be fixed to the handle 54. Thus, after the palm grasps the column on the handle 54, the palm is clamped and fixed by the palm fixing device 55, preventing the upper limb from moving during operation of the device, which would result in the inability to perform upper limb training and rehabilitation according to the movement trajectory set by the device. A large gear is mounted on the handle 54, and a small gear is rotatably mounted on the housing 52, meshing with the large gear. The large and small gears form a gear set 56. A stepper motor 58 is fixed to the housing 52, and its rotating shaft is fixedly connected to the small gear. The rotation of the stepper motor 58 drives the large gear, which in turn drives the handle 54. A front panel 57 is mounted on the side of the housing 52 facing the armrest 59, enclosing the bearing 53 and gear set 56 within the housing 52.

[0073] The palm fixing device 55 includes a gripping block 551, a double-hole connecting rod 552, a slot active connecting rod 553, a double rotating shaft 554 fixed by screws, a rotating key 555, a spring 556, a half-thread bolt 557, and a chuck 558. The gripping block 551 is in the shape of a swing arm, with a slot provided at one end thereof and a double rotating shaft 554 fixed thereto. The double rotating shaft 554 is fixed to the gripping block 551 by screws. The double rotating shaft comprises two relatively fixed rotating shafts, with the double-hole connecting rod 552 and the slot active connecting rod 553 respectively rotatably connected to the two rotating shafts of the double rotating shaft 554. The ends of the double-hole connecting rod 552 and the slot active connecting rod 553 are nested in the slots at the end of the gripping block 551. The half-thread bolt 557 includes a threaded section and an optical axis section. The threads of the threaded section are screwed into the handle 54. The optical axis section serves as the other rotating axis of the double-hole connecting rod 552, and the double-hole connecting rod 552 can slide on the optical axis section. One end of the slot active connecting rod 553 is rotatably connected to the double rotating axis 554. The other end is provided with a limiting protrusion 5531 on the side facing the handle 54 and a rotation key 555 on the side facing away from the handle 54. The rotation key 555 is provided with an annular protrusion 5551 and a handle 5552 at the end. The portion between the annular protrusion 5551 of the rotation key 555 and the handle 5552 slides through the chuck 558, which is fixed to the handle 54. A spring 556 is sleeved on the rotating key 555 between the annular protrusion 5551 and the chuck 558, and a groove is provided on the handle 54 corresponding to the limiting protrusion 5531 on the active connecting rod 553 of the card slot. Under the action of the spring 556, the limiting protrusion 5531 is inserted into the groove, and a plurality of anti-rotation protrusions are distributed on the end face of the limiting protrusion 5531. Under the action of the spring 556, the end face of the limiting protrusion 5531 is against the bottom surface of the groove, which can prevent the rotating key 555 from rotating, and cooperate with the double-hole connecting rod 552 to fix the hand clamping block 551, thereby adjusting the clamping position of the palm fixing device 55. To adjust the gear position, pull the rotary key 555, compress the spring 556, and separate the groove on the handle 54 from the limiting protrusion 5531 on the active connecting rod 553 of the slot. Turn the rotary key 555 to swing the active connecting rod 553, which in turn swings the clamping block 551 to adjust the clamping gear position. After the adjustment is completed, release the rotary key 555, and the active connecting rod 553 of the slot is pushed by the spring, so that the groove on the handle 54 and the limiting protrusion 5531 on the active connecting rod 553 cooperate to complete the limiting. In this embodiment, the chuck 558 is fixed to the handle 55 by four screws to determine the position of the spring. Through this palm fixing device 55, the palm fixing device 55 can be quickly adjusted to adapt to the user, fix the hand, and ensure smooth rehabilitation training.

[0074] In other embodiments, the palm fixing device 55 includes a hand clamping block 551. After adjusting the angle between the palm fixing device 55 and the handle 54, the palm fixing device 55 can be fixed to the handle 54 by bolts, nuts or screws. Other mechanisms that can adjust the angle between the palm fixing device 55 and the handle 54 and fix them can also be used.

[0075] An armrest 59 is also provided on the base 51. The armrest 59 is located on one side of the handle 54. After the palm of the hand is placed in the handle 54, the arm can be placed on the armrest 59. The armrest 59 includes a slide 591, an armrest base 592, a connecting screw 593, a limit screw 594, and a slide belt 595. The armrest base 592 is fixed to the base 51 by screws or bolts, thereby fixing the armrest 59 to the base 51. The slide 591 is fixed to the armrest base 592 by the connecting screw 593. The upper portion of the slide 591 is provided with a semicircular groove with a semicircular cross-section. A slide belt 595 is slidably provided in the semicircular groove. The slide belt 595 is a semicircular plate-shaped body. Its outer wall slides with the inner wall of the slide 591. After the slide belt 595 slides to a certain position, the position of the slide belt 595 is fixed by the limit screw 594.

[0076] The slide 595 and the straps work together to secure the forearm. The thickness of the forearm varies from person to person. Typically, the outer diameter of the forearm decreases as it approaches the wrist. During use, the slide 595 is moved according to the thickness of the user's forearm, so that the outer diameter of the forearm matches the slide 595. This allows the user to find the most suitable location for strapping, which increases comfort. The slide 595 is then secured to the slide groove 591, and the strap is then tied to the slide 595 to secure the forearm to the slide 595.

[0077] The semicircular opening of the chute 591 is provided with elongated holes extending along the length of the chute 591 on both sides, and threaded holes are provided on both sides of the slide belt 595. After the slide belt 595 slides to the appropriate position, the limit screws 594 are screwed through the elongated holes into the threaded holes to fix the slide belt 595 to the chute 591. The slide belt 595 is provided with holes for passing the strap.

[0078] The various motors of the device (including the drive motor 2, micro motor 431, and stepper motor 58) are electrically connected to the human-computer interaction platform. The human-computer interaction platform controls the operation of the motors according to the input information, and the information of the motor movements can be transmitted to the human-computer interaction platform and recorded.

[0079] The driving methods of the device of the present invention include the following two methods:

[0080] 1. Drag-to-Teach Method: The rehabilitation physician drags the handle to drive the device to simulate rehabilitation exercises. The motor movement information is transmitted to the human-computer interaction platform, which records the motor's rotation angle change process and posture information. The patient can call up this information at home. The patient holds the handle and places the upper limb on the armrest 59, so that the device reproduces the path planned by the rehabilitation physician and drives the patient's upper limb for rehabilitation.

[0081] 2. Algorithm planning method: Clinical data is collected in real time through electromyography and force sensors, and a plan suitable for the patient is planned in real time through the human-computer interaction platform. The method is recorded and called to promote the rehabilitation of the patient's upper limbs.

[0082] The device of the present invention has the characteristics of modular splicing. Each component unit of the device (including the working platform 5, handle 54, active arm 3, driven arm 4 and base 1) is equipped with fixed holes and slots. In actual production, whether to equip it with fixing parts can be determined according to the different processing accuracy, and the disassembly and assembly of the device is convenient. It breaks through the problem that conventional upper limb rehabilitation devices can only be used in relevant medical institutions and are not easy to carry. It realizes home rehabilitation and portability of the device. Figure 10 As shown, the device can be placed on a table for use. To fully utilize its lightweight, portable, and home-friendly features, it does not use parts made of high-density materials. The base 1 of the device does not provide any support and only determines the relative positions of the three drive motors 2. The stepped design of the active arm 3, driven arm 4, and work platform 5 from bottom to top prevents interference between the various parts of the device during movement and increases the working space of the work platform 5 for end-effector operations.

[0083] The present invention discloses a multi-degree-of-freedom desktop-level modular upper limb rehabilitation device equipped with a variable stiffness module. The device is suitable for upper limb rehabilitation for patients with neurological diseases such as stroke and cerebral palsy, musculoskeletal diseases such as frozen shoulder and elbow adhesions, and elderly people with upper limb dysfunction. To use the device, the wearer first grasps the handle with their hand, and a palm fixation device secures the wearer's palm. The human-computer interaction platform reads pre-recorded clinical assessment data, calculates and sets a suitable hand motion trajectory and wrist posture for the patient, and then transmits motion control data to the motors, causing each motor to rotate based on the control instructions. This in turn drives the work platform 5 to generate two-degree-of-freedom translational motion within a plane and flexion and extension rotation around the wrist. The stepper motor 58 drives the handle to generate internal and external rotational motion around the wrist, completing upper limb rehabilitation exercise training. The variable stiffness module influences the stiffness of the entire device by changing its own stiffness. The device's wide stiffness range can accommodate a variety of rehabilitation modes and different rehabilitation stages, improving the flexibility of the rehabilitation device and achieving more natural human-computer interaction. Fix the hand, fix the forearm with an arm support, and then control the operation of the device to achieve multi-dimensional rehabilitation of the shoulder, elbow and wrist.

[0084] In other embodiments of the present invention, the shape of the base 1 is not limited, as long as it can fix the position of the drive motor 2.

[0085] In other embodiments of the present invention, the shapes of the active arm 3, the driven arm 4, and the working platform 5 are not limited, as long as the active arm 3 can drive the driven arm 4, move the working platform 5 in a two-dimensional plane to drive the movement of the upper limbs, and can drive the wrist to rotate.

[0086] In other embodiments of the present invention, the number and position of the drive motors 2 on the base 1 are not limited, and the drive motors 2 can be changed to drive the working platform 5 to move on a two-dimensional plane by changing the control program of the drive motors 2.

[0087] In other embodiments of the present invention, the length adjustment structure of the driven arm 4 (including the long rod shell 44, the short rod shell 45, and the length gear column 42) is not limited to the structure of the present invention, and other structures capable of adjusting the arm length in the prior art may also be adopted. Correspondingly, the setting method of the variable stiffness module 43 is also adjusted accordingly.

[0088] In other embodiments of the present invention, the micro motor 431 may be replaced by other types of variable stiffness motors for driving the variable stiffness module.

[0089] In other embodiments of the present invention, the stepping motor may be replaced by other handle motors capable of driving the handle to rotate.

[0090] In other embodiments of the present invention, the screws, pins, limit pins, and bolts may be replaced by other forms of locking members.

[0091] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and alterations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A variable stiffness multi-degree-of-freedom upper limb rehabilitation device, comprising a base (1), characterized in that: A plurality of drive motors (2) are provided on the base (1), the drive shafts of the drive motors (2) are all connected to the active arm (3), the other end of the active arm (3) is hinged to the driven arm (4), the length of the driven arm (4) is adjustable, a variable stiffness module (43) is fixedly nested in the driven arm (4), the variable stiffness module (43) is driven by the variable stiffness motor, the other end of the driven arm (4) is hinged to the working platform (5), a handle (54) driven by the handle motor is provided on the working platform (5) to rotate the handle, and an arm support (59) is provided on one side of the handle (54); the drive motor (2), the variable stiffness motor, and the handle motor are electrically connected to the human-computer interaction platform.

2. The variable stiffness multi-degree-of-freedom upper limb rehabilitation device according to claim 1, characterized in that: The overall shape of the base (1) is an equilateral triangle, and the drive motor (2) is arranged at the vertex of the equilateral triangle; the base (1) comprises a motor fixing seat (11) located at the vertex of the equilateral triangle, a double convex connecting rod (12) and a concave-convex connecting rod (13) connecting the two motor fixing seats (11); the side wall of the motor fixing seat (11) is provided with two extension arms (iii) with an angle of 60 degrees, the end surface of the extension arm (iii) is provided with a groove, both ends of the double convex connecting rod (12) are provided with a boss, one end of the concave-convex connecting rod (13) is provided with a boss and the other end is provided with a groove; the boss at one end of the double convex connecting rod (12) is inserted into the The boss at the other end of the extension arm (iii) on the motor fixing seat (11) is inserted into the groove of the end of the concave-convex connecting rod (13); the boss at the other end of the concave-convex connecting rod (13) is inserted into the groove of the extension arm (iii) on the other motor fixing seat (11); a locking piece is passed through the joint between the motor fixing seat (11) and the double-convex connecting rod (12), the joint between the motor fixing seat (11) and the concave-convex connecting rod (13), and the joint between the double-convex connecting rod (12) and the concave-convex connecting rod (13) to achieve the fixed arrangement of the base (1); and the drive motor (2) is arranged on the motor fixing seat (11).

3. The variable stiffness multi-degree-of-freedom upper limb rehabilitation device according to claim 1, characterized in that: The active arm (3) comprises a type I connector (31), an active rod (32), and a type II connector I (33). The type I connector (31) is connected to the drive shaft of the drive motor (2). The side walls of the type I connector (31) and the type II connector I (33) are both provided with protrusions, and the end faces of the protrusions are provided with grooves. Both ends of the active rod (32) are provided with bosses, and the bosses at both ends are respectively inserted into the grooves of the type I connector (31) and the grooves of the type II connector I (33). Then, a locking piece is used to connect the type I connector (31), the active rod (32), and the type II connector I (33) to form the active arm (3).

4. The variable stiffness multi-degree-of-freedom upper limb rehabilitation device according to claim 1, characterized in that: The active arm (3) is hinged to the driven arm (4) via a rotating shaft (6), the rotating shaft comprising a round long nut (61) and a thumb screw (62), the round long nut (61) passing through a through hole of the active arm (3) and a through hole of the driven arm (4), and both ends of the round long nut (61) are threadedly connected to the thumb screw (62).

5. The variable stiffness multi-degree-of-freedom upper limb rehabilitation device according to claim 1, characterized in that: The driven arm (4) includes a type II connector II (41), a length shift column (42), a variable stiffness module (43), a long rod shell (44), a short rod shell (45), and a type II connector III (48). The type II connector II (41) is hinged to the active arm (3). A groove is provided on the raised end face of the side wall of the type II connector II (41). One end of the long rod shell (44) is provided with a boss. The boss of the long rod shell (44) is inserted into the groove of the type II connector II (41). A locking member is used to fix the joint of the type II connector II (41) and the long rod shell (44). The other end of the long rod shell (44) is open. The length shift column (42) is slidably inserted into the opening of the long rod shell (44). A plurality of holes are arranged axially on the length shift column (42). The side wall of the long rod shell (44) is provided with a boss. A through hole is provided, and a locking piece is used to pass through the through hole on the long rod shell (44) and one of the holes on the length gear column (42) to achieve length adjustment and fixation, and a slider (421) is provided at the end of the length gear column (42); an opening is provided at one end of the short rod shell (42), and the length gear column (42) is slidably penetrated in the opening of the short rod shell (45), and the slider (421) is fixedly connected to the variable stiffness module (43) in the short rod shell (45), and a boss is provided on the other end face of the short rod shell (45), and a protrusion with a groove on the end face is provided on the side wall of the II type connector III (48), and the boss on the short rod shell (45) is inserted into the groove of the II type connector III (48), and a locking piece is used to pass through the joint between the short rod shell (45) and the II type connector III (48) to achieve fixed connection.

6. The variable stiffness multi-degree-of-freedom upper limb rehabilitation device according to claim 5, characterized in that: The variable stiffness module (43) comprises a micro motor (431), an elastic rope (432), a force block (433), and a pulley (434). The micro motor (431) is fixed in a short rod housing (45). The rotating shaft of the micro motor (431) is connected to a gear set. A rotating column is provided on the output gear of the gear set. A through hole is provided on the rotating column. The force block (433) is fixedly connected to a slider (421). A through hole is provided on the force block (433). Pulleys (434) are provided on the inner walls of the short rod housing (45) on both sides of the force block (433). The shafts of the pulleys (434) are fixed on the inner wall of the short rod housing (45). The elastic rope (432) is arranged in a closed loop. The elastic rope (432) sequentially passes through the through hole on the rotating column, passes around the pulley (434) on one side, passes through the through hole on the force block (433), and passes around the pulley (434) on the other side.

7. The variable stiffness multi-degree-of-freedom upper limb rehabilitation device according to claim 6, characterized in that: A cover plate (46) is provided on the wall of the short rod housing (45), and the cover plate (46) is located at a position corresponding to the micro motor (431).

8. The variable stiffness multi-degree-of-freedom upper limb rehabilitation device according to claim 1, characterized in that: The working platform (5) comprises a base (51), a shell (52), a bearing (53), a handle (54), a palm fixing device (55), a gear set (56), a handle motor, and an arm support (59). The shell (52) is arranged on the base (51). The shell (52) and the handle (54) are both annular bodies. The bearing (53) is nested in the inner wall of the shell (52), and the handle (54) is nested in the inner wall of the bearing (53). A column convenient for hand holding is provided through the middle cavity of the handle (54). The palm fixing device (55) is rotatably arranged on the edge of the handle (54). The palm fixing device (55) is in the shape of a swing arm. A large gear is sleeved on the handle (54). A small gear meshing with the large gear is rotatably arranged on the shell (52). The large gear and the small gear form a gear set (56). The shell (52) is fixedly provided with a handle motor fixedly connected to the small gear.

9. The variable stiffness multi-degree-of-freedom upper limb rehabilitation device according to claim 8, characterized in that: An arm support (59) is provided on the base (51). After the palm is placed in the handle (54), the arm can be placed on the arm support (59). The arm support (59) includes a slide groove (591), an arm support base plate (592), and a slide belt (595). The arm support base plate (592) is fixed on the base (51). The slide groove (591) is fixed on the arm support base plate (592). A semicircular groove is provided on the upper part of the slide groove (591). A slide belt (595) is slidably provided in the semicircular groove. The slide belt (595) is a semicircular plate-shaped body. The outer wall of the slide belt (595) slides with the inner wall of the slide groove (591) and can be fixed.

10. The variable stiffness multi-degree-of-freedom upper limb rehabilitation device according to claim 1, characterized in that: The palm fixing device (55) comprises a hand clamping block (551), a double-hole connecting rod (552), a slot active connecting rod (553), a double rotating shaft (554), a rotating key (555), a spring (556), and a chuck (558). The hand clamping block (551) is in the shape of a swing arm. One end of the hand clamping block (551) is fixedly provided with a double rotating shaft (554). The double rotating shaft comprises two relatively fixed rotating shafts. The double-hole connecting rod (552) and the slot active connecting rod (553) are respectively rotatably connected to the two rotating shafts of the double rotating shaft (554). The double-hole connecting rod (552) is rotatably provided on the handle (54). The other end of the slot active connecting rod (553) is provided with a limiting protrusion (554) facing the side of the handle (54). 31) A rotating key (555) is provided on the side away from the handle (54), an annular protrusion (5551) is provided on the rotating key (555), and a handle (5552) is provided at the end. The portion between the annular protrusion (5551) and the handle (5552) of the rotating key (555) is slidably passed through the chuck (558), and the chuck (558) is fixed on the handle (54). An elastic member is sleeved on the rotating key (555) between the annular protrusion (5551) and the chuck (558), and a groove corresponding to the limiting protrusion (5531) on the active connecting rod (553) of the card slot is provided on the handle (54). Under the action of the elastic member, the limiting protrusion (5531) is inserted into the groove and rests on the bottom surface of the groove.

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