A wrist and elbow collaborative flexible rehabilitation robot based on joint decoupling strategy

Abstract

The application relates to a wrist-elbow collaborative flexible rehabilitation robot based on a joint decoupling strategy, which comprises a finger limiting bandage, an elbow flexible driver, a gas transmission structure, an elbow tight binding structure, a wrist flexible driver, a wrist flexible driver fixing sleeve, a module connecting piece A and a module connecting piece B. The elbow flexible driver and the wrist flexible driver are both pneumatic soft body drivers, and the connecting pieces of each are made of flexible materials. The wrist-elbow collaborative flexible rehabilitation robot based on the joint decoupling strategy is ingenious and reasonable in structure. Through cooperation of the wrist joint driver and the elbow joint driver, the flexible rehabilitation robot is innovatively used to realize internal rotation / external rotation movement of the elbow joint of the human upper limb, realizes a rehabilitation action of wrist-elbow collaborative training, improves the adaptability of the upper limb exoskeleton rehabilitation robot to rehabilitation needs, improves the wearing comfort and motion flexibility, and finally realizes flexible, soft and safe rehabilitation movement of the wrist and elbow joints.

Description

Technical Field

[0001] This invention relates to the field of robotics, and in particular to a wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy. Background Technology

[0002] Stroke, also known as cerebrovascular accident, is a local brain dysfunction caused by acute cerebrovascular disease. It is the second leading cause of death and the third leading cause of disability worldwide. It is characterized by high incidence, high mortality, high disability rate, and high recurrence rate. Upper limb dysfunction is a common problem in stroke. Therefore, effective rehabilitation treatment is an effective way to improve motor dysfunction in hemiplegic upper limbs.

[0003] Previously, the main rehabilitation method involved manual training assisted by therapists. However, this method consumed a significant amount of medical resources. With the development of intelligent robotics technology, exoskeleton robot-assisted rehabilitation technology has gradually replaced manual rehabilitation, alleviating the pressure on medical resources. As rehabilitation demands continue to increase, traditional rigid exoskeleton rehabilitation robots are insufficient for rehabilitation work, exhibiting poor flexibility and a tendency to cause secondary injuries. In recent years, the emergence of flexible exoskeleton rehabilitation robots has solved this problem. They are highly flexible and easy to carry. Flexible upper limb exoskeleton rehabilitation robots are flexible rehabilitation robots that organically integrate multiple disciplines such as robotics, ergonomics, informatics, fluid mechanics, control science, and medical rehabilitation, enabling partial functional compensation in the upper limbs.

[0004] However, existing flexible upper limb exoskeleton rehabilitation robots generally present two problems:

[0005] The first problem is that there are few devices available for wrist internal / external rotation rehabilitation movements, making it difficult to adapt to the diverse rehabilitation subjects and needs.

[0006] The second issue is that while existing flexible upper limb exoskeleton rehabilitation robots partially utilize flexible actuation and transmission methods such as pneumatic muscles and ropes, most of the structures in contact with the upper limb are rigid. Like rigid exoskeleton robots, these can still potentially cause secondary injury to the patient's upper limb, exhibiting poor compliance. Furthermore, most upper limb exoskeleton rehabilitation robots do not adequately consider the fit between the robot and the human upper limb, failing to effectively improve patient comfort and compliance during rehabilitation, thus hindering the successful execution of rehabilitation movements. Summary of the Invention

[0007] Therefore, the technical problem to be solved by the present invention is to overcome the difficulties in the prior art, such as the limited number of devices for wrist joint internal / external rotation rehabilitation movements in flexible upper limb exoskeleton robots, and the fact that although some flexible drive and transmission methods such as pneumatic muscles and ropes are used, most of the structures in contact with the upper limb are rigid structures.

[0008] To address the aforementioned technical problems, this invention provides a wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy, comprising: a finger limiting strap, an elbow flexible actuator, a gas delivery tube, an elbow tightening structure, a wrist flexible actuator, module connector A, module connector B, and a wrist flexible actuator fixing sleeve; wherein, the elbow flexible actuator and the wrist flexible actuator are both pneumatic soft actuators, and the finger limiting strap, the elbow tightening structure, module connector A, and module connector B are all made of flexible materials, and the finger limiting strap, the elbow tightening structure, module connector A, and module connector B are attached to the surface of the human body. This invention relates to a wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy. With its ingenious and rational structure, it innovatively achieves internal / external rotation of the elbow joint of the upper limb through the collaboration of wrist and elbow joint actuators. This enables wrist-elbow coordinated rehabilitation exercises and simultaneously improves the adaptability of the upper limb exoskeleton rehabilitation robot to rehabilitation needs, enhancing wearing comfort and movement smoothness. Ultimately, it achieves flexible, smooth, and safe rehabilitation movements of the wrist and elbow joints to meet diverse rehabilitation needs, improve patient wearing comfort, enhance the smoothness of rehabilitation movements, and safely and efficiently complete rehabilitation actions.

[0009] In one embodiment of the present invention, both module connector A and module connector B serve a connecting function. One end of the elbow flexible actuator is connected to the thumb end of the finger limiting strap via module connector A, and the other end of the elbow flexible actuator is connected to module connector B. The finger limiting strap is connected to module connector A, the elbow tightening structure is connected to module connector B, the wrist flexible actuator fixing sleeve is fitted on the human wrist, and two gas delivery tubes are provided, which are respectively connected to the elbow flexible actuator and the wrist flexible actuator.

[0010] In one embodiment of the present invention, the wrist flexible actuator includes a flexible semi-cylindrical air cavity, wound fibers, a unilateral limiting layer, and a flexible bottom layer.

[0011] In one embodiment of the present invention, the flexible semi-cylindrical air cavity is in the shape of a semi-cylindrical body and is made of silicone elastomer. One end of the flexible semi-cylindrical air cavity has a pneumatic interface, which is the interface of the gas delivery pipe.

[0012] In one embodiment of the present invention, the winding fiber is Kevlar fiber, and the winding fiber is bidirectionally wound around the outside of the flexible semi-cylindrical air cavity.

[0013] In one embodiment of the present invention, the unilateral limiting layer is a flexible nylon material, and the unilateral limiting layer is attached between the flexible semi-cylindrical air cavity and the flexible bottom layer.

[0014] In one embodiment of the present invention, the flexible bottom layer is made of the same silicone material as the flexible semi-cylindrical air cavity, and the flexible bottom layer is in the shape of a cuboid.

[0015] In one embodiment of the present invention, the elbow flexible actuator includes a locking mechanism, a second pneumatic interface, and a fiber-constrained air chamber. The second pneumatic interface is the interface of the gas delivery pipe, the fiber-constrained air chamber is a flexible air chamber made of McKibben muscle sheath braided tubing, and the locking mechanism is a bolt locking mechanism that locks the second pneumatic interface and the fiber-constrained air chamber.

[0016] In one embodiment of the present invention, both the elbow tightening structure and the wrist flexible actuator fixing sleeve are made of Velcro straps.

[0017] In one embodiment of the present invention, the rehabilitation robot further includes a contact force sensing system and a joint angle and overall posture sensing system. The contact force sensing system includes multiple thin-film pressure sensors and multiple tension sensors, and the joint angle and overall posture sensing system includes multiple bending sensors and a six-axis posture sensor.

[0018] The technical solution of the present invention has the following advantages compared with the prior art:

[0019] 1) The wrist-elbow coordinated flexible rehabilitation robot disclosed in this invention has an ingenious and reasonable structure. It addresses the fact that existing technologies rarely achieve internal / external rotation rehabilitation movements of the elbow joint. Through the collaboration of wrist joint actuators and elbow joint actuators, this invention innovatively realizes the internal / external rotation movements of the elbow joint of the human upper limb by the flexible rehabilitation robot, realizes the rehabilitation movements of wrist-elbow coordinated training, and improves the adaptability of the upper limb exoskeleton rehabilitation robot to different rehabilitation subjects and rehabilitation needs.

[0020] 2) The wrist-elbow coordinated flexible rehabilitation robot disclosed in this invention addresses the problem that although some existing upper limb exoskeleton rehabilitation robots use flexible drive and transmission methods such as pneumatic muscles and ropes, most of the parts in contact with the upper limb are rigid structures. Like rigid exoskeleton robots, they may still cause secondary damage to the patient's upper limb and have poor flexibility. The robot adopts fully flexible components that conform to the human body, improves wearing comfort and movement flexibility, and achieves flexible, compliant and safe rehabilitation tasks. Attached Figure Description

[0021] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0022] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the wrist-elbow coordinated flexible rehabilitation robot based on the joint decoupling strategy of this invention. Figure 1 ;

[0023] Figure 2 This is a schematic diagram of the overall three-dimensional structure of the wrist-elbow coordinated flexible rehabilitation robot based on the joint decoupling strategy of this invention. Figure 2 ;

[0024] Figure 3 This is a schematic diagram of the overall structure of the wrist joint flexible actuator of the wrist-elbow coordinated flexible rehabilitation robot based on the joint decoupling strategy of the present invention.

[0025] Figure 4 This is a schematic diagram of the key structure of the wrist joint flexible actuator of the wrist-elbow coordinated flexible rehabilitation robot based on the joint decoupling strategy of the present invention.

[0026] Figure 5 This is a schematic diagram of the overall structure of the elbow flexible actuator of the wrist-elbow coordinated flexible rehabilitation robot based on the joint decoupling strategy of the present invention.

[0027] Figure 6 This is a schematic diagram of the key structure of the elbow flexible actuator of the wrist-elbow coordinated flexible rehabilitation robot based on the joint decoupling strategy of the present invention.

[0028] Explanation of reference numerals in the accompanying drawings: 10. Finger limiting strap; 11. Elbow flexible actuator; 111. Locking mechanism; 112. Pneumatic interface; 113. Fiber restraint air chamber; 12. Gas delivery tube; 13. Elbow joint tightening structure; 14. Wrist joint flexible actuator; 141. Flexible semi-cylindrical air chamber; 142. Wrapped fiber; 143. Unilateral limiting layer; 144. Flexible bottom layer; 15. Module connector A; 16. Module connector B; 17. Wrist joint flexible actuator fixing sleeve. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0030] Reference Figure 1-6 As shown, the wrist-elbow coordinated flexible rehabilitation robot based on the joint decoupling strategy of the present invention includes a finger limiting strap 10, an elbow flexible actuator 11, a gas delivery tube 12, an elbow joint tightening structure 13, a wrist joint flexible actuator 14, a module connector A15, a module connector B16, and a wrist joint flexible actuator fixing sleeve 17.

[0031] The wrist joint flexible actuator 14 is fixed to the wrist joint via a wrist joint flexible actuator fixing sleeve 17. Gas is supplied to the wrist joint flexible actuator 14 through a gas delivery tube 12, enabling unilateral bending of the wrist joint flexible actuator 14 to drive the extension / flexion movement of the upper limb wrist joint. One end of the elbow flexible actuator 11 is connected to the finger limiting strap 10 via module connector A, and the other end is connected to the elbow joint tightening structure 13 via module connector B16. Gas is supplied to the elbow flexible actuator 11 to achieve the contraction / extension of the elbow joint flexible actuator. The finger limiting strap 10 restricts the movement of the thumb due to the inability of the palm to bend in the opposite direction. Therefore, the finger limiting strap 10 is used to restrict the rotation of the thumb when the elbow flexible actuator 11 contracts. The extension / flexion movement of the upper limb wrist joint achieved by the wrist joint flexible actuator 14 restricts the extension / flexion movement of the wrist joint when the elbow flexible actuator 11 contracts, thereby decoupling the elbow joint movement and achieving elbow-wrist combined rehabilitation training. In addition, the present invention uses fully flexible components that conform to the human body, improving wearing comfort and movement flexibility, and enabling flexible, smooth and safe rehabilitation tasks.

[0032] The aforementioned module connectors A15 and B16 serve a connecting function. One end of the elbow flexible actuator 11 is connected to the thumb end strap of the finger limiting strap 10 and module connector A15. The other end of the elbow flexible actuator 11 is connected to module connector B16. The finger limiting strap 10 is connected to module connector A15. The elbow tightening structure 13 is connected to module connector B16. The wrist joint flexible actuator fixing sleeve 17 is fixed on the human wrist. The wrist flexible actuator 14 is connected to the wrist joint flexible actuator fixing sleeve 17. The pneumatic delivery tube 12 has two tubes, which are respectively connected to the elbow flexible actuator 11 and the wrist joint flexible actuator 14.

[0033] The aforementioned wrist joint flexible actuator 14 includes a flexible semi-cylindrical air cavity 141, a wound fiber 142, a unilateral limiting layer 143, and a flexible bottom layer 144.

[0034] The aforementioned flexible wrist joint actuator 14 is cast using a silicone solution through a molding process. During casting, a centrifuge is used to remove air bubbles, improving the material strength of the actuator and resulting in high airtightness. The flexible semi-circular air cavity, the single-sided limiting layer, and the flexible bottom layer are connected by a colloidal solution.

[0035] The aforementioned flexible semi-cylindrical air cavity 141 is semi-cylindrical in shape and is made of highly compressible and stretchable silicon elastomer. One end has a pneumatic interface, which is the interface of the gas delivery pipe 12.

[0036] The aforementioned wound fiber 142 is a Kevlar fiber that is bidirectionally wound at a certain angle in the flexible semi-cylindrical air cavity 141.

[0037] The aforementioned flexible bottom layer 144 is made of the same silicone material as the flexible semi-cylindrical air cavity 141 and is in the shape of a cuboid. The single-sided limiting layer 143 is a non-stretchable nylon flexible material that is attached between the flexible semi-cylindrical air cavity 141 and the flexible bottom layer 144.

[0038] The aforementioned wound fiber 142 is mainly due to the uneven expansion of the air chamber of the wrist joint flexible actuator 14 after gas is filled, which hinders effective control of the actuator, i.e., the so-called balloon effect. The wound fiber 142 can limit the radial expansion of the chamber, maximize axial deformation, improve the system's energy conversion rate, increase the actuator's bending resistance, and improve the strength of the inner wall of the chamber. The fiber winding method of the wrist joint flexible actuator 14 is divided into unidirectional winding and bidirectional winding. Since the number of winding turns is half that of bidirectional winding, the constraint effect of single-fiber radial winding on the flexible actuator is smaller, and therefore it is more prone to bending deformation compared to bidirectional winding. However, due to the certain angle between the fiber winding and the radial end face of the actuator, the end of the flexible actuator rotates axially. Since the actuator used in the experiment is semi-cylindrical, the rotation angle is relatively small. Bidirectional symmetrical radial winding will cancel out the rotation effects in the two directions due to symmetry, and there will be basically no axial rotation. The specific winding method can be flexibly changed according to actual needs.

[0039] The aforementioned flexible elbow actuator 11 includes a locking mechanism 111, a second pneumatic interface 112, and a fiber-constrained air chamber 113. The second pneumatic interface 112 is the interface of the gas delivery pipe 12, and the fiber-constrained air chamber 113 is a flexible air chamber made of McKibben muscle sheath braided tubing. The locking mechanism 111 is a bolt locking mechanism that locks the second pneumatic interface 112 and the fiber-constrained air chamber 113.

[0040] The wrist joint flexible actuator 14 described above is a pneumatic tendon type actuator. In other embodiments, it can also be other types of flexible actuators that can achieve contraction and extension.

[0041] The aforementioned finger restraint strap 10 and the module connectors A15 and B16 are all made of non-stretchable flexible materials that conform to the human body.

[0042] The aforementioned finger restraint strap 10 utilizes the characteristic that the palm cannot bend in the opposite direction to restrict the bending of the thumb. When the thumb bends due to the contraction pull generated by the elbow flexible actuator 11, the palm provides a reverse force through the finger restraint strap 10 to restrict the bending of the thumb.

[0043] Both the elbow tightening structure 13 and the wrist joint flexible actuator fixing sleeve 17 are tightening straps modified from Velcro.

[0044] The elbow tightening structure described above is used to replace the traditional rigid mechanism to bear the tension of the elbow flexible actuator 11. The wrist joint flexible actuator fixing sleeve 17 is used to fix the wrist joint flexible actuator 14. Both are modified from Velcro straps. In other examples, other forms of tightening structures such as suction cups, flexible straps, etc. can also be used.

[0045] The rehabilitation robot of the present invention also includes a contact force sensing system and a joint angle and overall posture sensing system. The contact force sensing system includes multiple thin-film pressure sensors and multiple tension sensors, and the joint angle and overall posture sensing system includes multiple bending sensors and a six-axis posture sensor.

[0046] A tension sensor is installed at connector B16 of the upper limb exoskeleton flexible rehabilitation robot module. Feature points are selected at the contact points between the wrist joint flexible actuator 14 and the human body, and pressure sensors are installed at these points to measure the output force of the flexible actuator in real time. Using the mathematical model of the flexible pneumatic actuator—the coupling relationship between output force F, input air pressure P, and deformation δ—the relationship between input air pressure P and deformation δ can be obtained given the output force. Therefore, by inputting air pressure through the pneumatic module, the deformation δ of the pneumatic actuator is controlled, thereby driving the upper limb exoskeleton flexible rehabilitation robot to perform rehabilitation movements. A flexion sensor is placed between the unilateral limiting layer and the flexible bottom layer of the wrist joint flexible actuator 14 to measure the flexion angle of wrist extension / flexion movements in real time. A six-axis posture sensor is placed on the forearm to measure the flexion angle of elbow internal / external rotation movements in real time. The real-time sensed information is used as feedback to correct the motion trajectory, improving the motion accuracy of the rehabilitation robot and enhancing user comfort and rehabilitation effectiveness.

[0047] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy, characterized in that, include: It includes a finger restraint strap, an elbow flexible actuator, a gas delivery tube, an elbow tightening structure, a wrist flexible actuator, module connector A, module connector B, and a wrist flexible actuator fixing sleeve. The elbow flexible actuator and the wrist flexible actuator are both pneumatic soft actuators. The finger limiting strap, the elbow tightening structure, the module connector A and the module connector B are all made of flexible materials, and the finger limiting strap, the elbow tightening structure, the module connector A and the module connector B are attached to the surface of the human body. Both module connector A and module connector B serve a connecting function. One end of the elbow flexible actuator is connected to the thumb end of the finger limiting strap via module connector A, and the other end of the elbow flexible actuator is connected to module connector B. The finger limiting strap is connected to module connector A, and the elbow tightening structure is connected to module connector B. The wrist flexible actuator fixing sleeve is fitted on the human wrist. There are two gas delivery tubes, and the two gas delivery tubes are respectively connected to the elbow flexible actuator and the wrist flexible actuator. The finger restraint strap can restrict the movement of the thumb by limiting the palm's inability to bend in the opposite direction. Therefore, by using the finger restraint strap to limit the rotation of the thumb when the elbow flexible actuator contracts, and by using the wrist flexible actuator to achieve the extension / flexion of the upper limb wrist joint, the extension / flexion of the wrist joint when the elbow flexible actuator contracts is restricted, thus achieving decoupling of elbow joint movements.

2. The wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy according to claim 1, characterized in that: The wrist flexible actuator includes a flexible semi-cylindrical air cavity, wound fibers, a unilateral limiting layer, and a flexible bottom layer.

3. The wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy according to claim 2, characterized in that: The flexible semi-cylindrical air cavity is semi-cylindrical in shape and is made of silicone elastomer. One end of the flexible semi-cylindrical air cavity has a pneumatic interface, which is the interface of the gas delivery pipe.

4. The wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy according to claim 2, characterized in that: The winding fiber is Kevlar fiber, and the winding fiber is bidirectionally wound around the outside of the flexible semi-cylindrical air cavity.

5. The wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy according to claim 2, characterized in that: The single-sided limiting layer is made of flexible nylon material, and the single-sided limiting layer is attached between the flexible semi-cylindrical air cavity and the flexible bottom layer.

6. The wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy according to claim 2, characterized in that: The flexible bottom layer is made of the same silicone material as the flexible semi-cylindrical air cavity, and the flexible bottom layer is rectangular.

7. The wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy according to claim 1, characterized in that: The elbow flexible actuator includes a locking mechanism, a second pneumatic interface, and a fiber-constrained air chamber. The second pneumatic interface is the interface of the gas delivery pipe. The fiber-constrained air chamber is a flexible air chamber made of McKibben muscle sheath braided tubing. The locking mechanism is a bolt locking mechanism that locks the second pneumatic interface and the fiber-constrained air chamber.

8. The wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy according to claim 1, characterized in that: Both the elbow tightening structure and the wrist flexible actuator fixing sleeve use Velcro straps.

9. The wrist-elbow coordinated flexible rehabilitation robot based on a joint decoupling strategy according to claim 1, characterized in that: The rehabilitation robot also includes a contact force sensing system and a joint angle and overall posture sensing system. The contact force sensing system includes multiple thin-film pressure sensors and multiple tension sensors, and the joint angle and overall posture sensing system includes multiple bending sensors and a six-axis posture sensor.

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