Passive wrist rotation damping mechanism, myoelectric prosthetic hand and prosthetic body

Abstract

The application belongs to the technical field of artificial limbs and orthoses, and discloses a passive wrist joint rotation damping mechanism, an electromyographic artificial limb hand and an artificial limb body. The mechanism comprises a stud rotation plate, a first convex washer, a second convex washer, a connecting bottom plate and a nut. The stud rotation plate comprises a cylinder and a stud connected to the cylinder. The end of the stud away from the cylinder is sequentially threaded through the first convex washer, the second convex washer and the connecting bottom plate, and is then threadedly connected to the nut. The convex plane of the first convex washer is in contact with the convex plane of the second convex washer. The nut is used to press the connecting bottom plate by being screwed with the stud, so that the first convex washer and the second convex washer generate extrusion force in the vertical direction. The friction force generated by the extrusion of the first convex washer and the second convex washer forms the rotation damping torque of the mechanism. The rotation of the mechanism can be realized by overcoming the friction force, so that passive rotation is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of prosthetics and orthotics, and more specifically, relates to a passive wrist joint rotation damping mechanism, a myoelectric prosthetic hand, and a prosthetic limb. Background Technology

[0002] The wrist joint mechanism is one of the devices connecting the myoelectric prosthetic hand to the prosthetic socket. The wrist joint mechanism needs to be compatible with the quick-change connector of the front myoelectric prosthetic hand and the connection method of the rear prosthetic socket, allowing for a certain angle of relative rotation between the myoelectric prosthetic hand and the prosthetic socket. This allows for adjustment of the relative angle between the myoelectric prosthetic hand and the prosthetic socket when forearm amputees experience discomfort. Research shows that the number of people with upper limb amputations is large, and the total number of forearm amputees is considerable. However, many manufacturers produce prosthetic products with low technical content and poor quality.

[0003] Compared to other prosthetic products, the wrist joint mechanism of prostheses receives less attention. Currently, there are almost no forearm prostheses with wrist joints on the market. Users often need to bend over to adjust their arm gripping, or the lack of flexible design solutions leads to complex and costly replacements of myoelectric prosthetic hands and prosthetic sockets. For example, the connector for connecting a myoelectric prosthetic hand disclosed in Chinese invention patent CN112336582A requires a traction device and a positioning pin assembly, resulting in high manufacturing costs and complex replacement operations. Another example is the wrist joint mechanism disclosed in Chinese invention patent CN109434819A, which has a relatively complex structure requiring gears and relying on external power for control, making passive quick replacement impossible. However, with the rapid development of robotic dexterous hand technology, prosthetic products, especially myoelectric prosthetic hands and prosthetic sockets, are becoming increasingly common. How to connect these two products while allowing a certain degree of relative rotation, further facilitating the lives of people with limb disabilities, has become a key concern in this field. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the prior art, the present invention provides a passive wrist joint rotation damping mechanism, a myoelectric prosthetic hand and a prosthetic limb. The wrist joint rotation damping mechanism can be used to realize the dual-function connection of mechanical and electrical signals between the quick-change connector of the myoelectric prosthetic hand and the prosthetic socket, and to complete the relative rotation between the myoelectric prosthetic hand and the prosthetic socket at a certain angle, thereby facilitating the movement of people with limb disabilities.

[0005] To achieve the above objectives, according to one aspect of the present invention, a passive wrist joint rotation damping mechanism is provided. The passive wrist joint rotation damping mechanism includes a stud rotating plate, a first convex washer, a second convex washer, a connecting base plate, and a nut. The stud rotating plate includes a cylinder connected to a stud. One end of the stud away from the cylinder passes sequentially through the first convex washer, the second convex washer, and the connecting base plate before being threaded to the nut. The convex surface of the first convex washer contacts the convex surface of the second convex washer.

[0006] The nut, by tightening with the stud, presses the connecting base plate, causing the first convex washer and the second convex washer to generate a compressive force in the vertical direction. The friction generated by the compression between the first convex washer and the second convex washer forms the rotational damping torque of the passive wrist joint rotational damping mechanism. By overcoming the friction, the rotation of the passive wrist joint rotational damping mechanism can be achieved, thereby realizing passive rotation.

[0007] Furthermore, the cylinder has four protrusions evenly distributed around its circumference, and each protrusion has a first threaded hole. The passive wrist joint rotation damping mechanism is connected to the quick-change connector of the myoelectric prosthetic hand through the first threaded hole.

[0008] Furthermore, the stud rotating plate is also provided with a receiving hole, which penetrates the cylinder and the stud, through which wires transmitting current and signals in the myoelectric prosthesis hand pass to connect with the control board inside the prosthesis receiving cavity.

[0009] Furthermore, the structure of the first convex washer is the same as that of the second convex washer.

[0010] Furthermore, the first convex washer is conical, comprising a large end face, a small end face, and a fan-shaped surface connecting the large end face and the small end face, wherein the small end face is a convex plane.

[0011] Furthermore, a plurality of spaced stripes are formed on the convex plane, the stripes being used to increase the friction between the first convex pad and the second convex pad.

[0012] Furthermore, a groove is provided at one end of the connecting base plate, and a central hole is provided on the bottom surface of the groove. The central hole penetrates the connecting base plate and is used for the stud to pass through and to provide wiring space for the control signal line and power line of the myoelectric prosthetic hand; the groove is used to accommodate the first convex washer and the second convex washer.

[0013] Furthermore, the connecting base plate is provided with four evenly distributed second threaded holes on its circumference, and the connecting base plate is threadedly connected to the prosthesis receiving cavity through the four second threaded holes.

[0014] The present invention provides a myoelectric prosthetic hand, the myoelectric prosthetic hand including a quick-change connector and a passive wrist joint rotation damping mechanism as described above, the quick-change connector being connected to the passive wrist joint rotation damping mechanism.

[0015] The present invention also provides a prosthetic limb, the prosthetic limb comprising a myoelectric prosthetic hand, a quick-change connector, a prosthetic receiving cavity, and a passive wrist joint rotation damping mechanism as described above, wherein the quick-change connector is connected to the myoelectric prosthetic hand, and the passive wrist joint rotation damping mechanism is connected to the quick-change connector and the prosthetic receiving cavity.

[0016] In summary, compared with the prior art, the passive wrist joint rotation damping mechanism, myoelectric prosthetic hand, and prosthetic limb provided by the present invention have the following beneficial effects:

[0017] 1. The passive wrist joint rotation damping mechanism achieves a simple threaded connection between the quick-change connector of the myoelectric prosthetic hand and the prosthetic receiving cavity, enabling simple and quick disassembly and replacement. It is convenient to disassemble and repair when the patient feels uncomfortable with the myoelectric prosthetic hand or when switching to other actuators.

[0018] 2. The relative rotation between the myoelectric prosthetic hand and the prosthetic socket is mainly achieved by the friction between the two convex pads in the passive wrist joint rotation damping mechanism. This allows for relative rotation at any angle within a certain range, enabling the operator to adjust the relative angle according to their own needs, resulting in high flexibility.

[0019] 3. The damped relative rotation between the myoelectric prosthetic hand and the prosthetic socket mainly relies on overcoming the friction of the two convex washers. By properly adjusting the tightness between the nut and the stud, the vertical compressive force between the two convex washers can be changed, thereby changing the magnitude of the damping. Therefore, the operator can adjust the magnitude of the rotational damping according to their own needs before wearing the prosthetic socket, which is convenient and flexible.

[0020] 4. When the myoelectric prosthetic hand and the prosthetic socket rotate relative to each other, the wires that transmit current and signals between them undergo a slight rotation. Since the power line and signal line are both located at the axis of rotation, the reserved wire length margin during relative rotation can ensure a stable circuit connection during rotation, thereby enabling the myoelectric prosthetic hand to receive a stable control signal.

[0021] 5. The passive wrist joint rotation damping mechanism has a compact structure, small size, low manufacturing cost, strong overall stability, and high reliability.

[0022] 6. The wrist joint mechanism provided by this invention can be consistent with the circumference of a standardized prosthesis socket in terms of size. The connecting base plate of the wrist joint mechanism can be adapted to the standard specifications of the prosthesis socket. Different specifications of connecting modules can be designed according to the different sizes of prosthesis sockets and quick-change connectors, adapting to a variety of products and further realizing mass production. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a passive wrist joint rotation damping mechanism provided by the present invention;

[0024] Figure 2 yes Figure 1 An exploded schematic diagram of the passive wrist joint rotation damping mechanism.

[0025] Figure 3 yes Figure 1 A schematic diagram of the stud rotating plate of the passive wrist joint rotation damping mechanism.

[0026] Figure 4 yes Figure 1 A schematic diagram of the connecting base plate of the passive wrist joint rotation damping mechanism;

[0027] Figure 5 yes Figure 1 Exploded view of the passive wrist joint rotation damping mechanism, quick-change connector female assembly, standard parts for prosthesis receiving cavity interface, and conductive slip ring.

[0028] Figure 6 Is Figure 2 A schematic diagram showing the usage status of the passive wrist joint rotation damping mechanism.

[0029] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-stud rotating plate, 2-first convex washer, 3-second convex washer, 4-connecting base plate, 5-inner nut, 6-outer nut, 7-quick-change connector female assembly, 8-spring, 9-prosthetic receiving cavity interface standard part, 10-conductive slip ring, 11-prosthetic forearm connecting plate, 12-prosthetic upper arm connecting plate. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 This invention provides a passive wrist joint rotation damping mechanism, comprising a stud rotating plate 1, a first convex washer 2, a second convex washer 3, a connecting base plate 4, an inner nut 5, and an outer nut 6. The first convex washer 2, the second convex washer 3, the connecting base plate 4, the inner nut 5, and the outer nut 6 are sequentially connected to the stud rotating plate 1. The convex surface of the first convex washer 2 contacts the convex surface of the second convex washer 3. The inner nut 5 and the outer nut 6 are threadedly connected to the stud rotating plate 1. Tightening the inner nut 5 and the outer nut 6 to the stud rotating plate 1 can compress the connecting base plate 4, causing a large compressive force in the vertical direction on the first convex washer 2 and the second convex washer 3. The friction generated by the compression between the first convex washer 2 and the second convex washer 3 forms the rotational damping torque of the passive wrist joint rotation damping mechanism. By overcoming static friction with a certain force, the passive wrist joint rotation damping mechanism can be rotated, thus achieving the function of passive rotation. The stud rotating plate 1 is used to connect the quick-change connector of the myoelectric prosthetic hand, and the connecting base plate 4 is used to connect the prosthetic receiving cavity.

[0032] The stud rotating plate 1 includes a cylinder and a stud. One end of the cylinder has an annular groove, and the other end is fixed with one end of the stud. Four protrusions are evenly distributed around the circumference of the cylinder, each protrusion having a first threaded hole. The central axis of the first threaded hole coincides with the central axis of the stud rotating plate 1. The stud rotating plate 1 also has a receiving hole that passes through the cylinder and the stud, and its central axis coincides with the central axis of the stud rotating plate 1. The receiving hole is used for the wires transmitting current and signals in the myoelectric prosthesis hand to connect to the control board inside the prosthesis receiving cavity. The other end of the stud passes sequentially through the first convex washer 2, the second convex washer 3, and the connecting base plate 4 before being threaded to the inner nut 5 and the outer nut 6.

[0033] Please see Figure 5 The four first threaded holes are used to make threaded connections with the quick-change connector female assembly 7, thereby realizing the connection between the passive wrist joint rotation damping mechanism and the quick-change connector of the myoelectric prosthetic hand.

[0034] The structure of the first convex washer 2 is the same as that of the second convex washer 3. The first convex washer 2 is conical, including a large end face, a small end face, and a fan-shaped surface connecting the large end face and the small end face, wherein the small end face is the convex plane. The convex plane of the first convex washer 2 contacts the convex plane of the second convex washer 3. Multiple spaced stripes are formed on the convex plane, which makes the relative rotational contact between the first convex washer 2 and the second convex washer 3 tighter, thereby increasing the frictional force between them. The frictional force generated by the two pressing together forms the rotational damping torque of the passive wrist joint rotational damping mechanism. By overcoming the static friction with a certain force, the rotation of the passive wrist joint rotational damping mechanism can be realized.

[0035] One end of the connecting base plate 4 has a groove, and the bottom surface of the groove has a central hole that penetrates the connecting base plate 4. The groove is used to accommodate the first convex washer 2 and the second convex washer 3. The central hole is used for the stud to pass through and can provide wiring space for the control signal lines and power lines of the myoelectric prosthetic hand. The circumference of the connecting base plate 4 also has four evenly distributed second threaded holes. The connecting base plate 4 forms a threaded connection with the prosthetic receiving cavity through the four second threaded holes, thereby realizing the overall connection of the myoelectric prosthetic hand and the prosthetic receiving cavity.

[0036] The outer nut 6 and inner nut 5 mainly serve to provide longitudinal pressure for the contact between the two convex washers during the screwing and locking process. Furthermore, this method can be used to adjust the damping of the wrist rotation degree of freedom, and at the same time, it can provide a fastening effect for the connection between the stud rotating plate 1 and the connecting base plate 4.

[0037] In one embodiment, the myoelectric prosthetic hand includes a quick-change connector female assembly 7 and a spring 8 connected to the quick-change connector female assembly 7, with an annular groove for receiving the spring 8. The prosthetic socket includes a prosthetic socket interface standard 9 and a conductive slip ring 10. The conductive slip ring 10 is mounted on the prosthetic socket interface standard 9 and, in conjunction with the passive wrist joint rotation damping mechanism, further realizes the function of axial connection of the mechanical structure. The upper end wire connected to the quick-change connector female assembly 7 can rotate relative to the wire fixed on the prosthetic socket within the deformation range of the reserved wire length, providing a basis for the development of humanoid robotic arms for the wrist. In other robot design directions, the conductive slip ring 10 can also be used to further match the wrist degrees of freedom, making the product more durable.

[0038] Please see Figure 6Considering the similar functional characteristics of the elbow and wrist joints in the human body, this rotational damping mechanism can also be applied to the elbow joint. Specifically, the prosthetic forearm is fixed to the prosthetic forearm connecting plate 11, and the prosthetic upper arm is fixed to the prosthetic upper arm connecting plate 12. The convex surfaces of the first convex washer 2 and the second convex washer 3 contact each other and are placed between the prosthetic forearm connecting plate 11 and the prosthetic upper arm connecting plate 12. The prosthetic upper arm connecting plate 12 is then pressed together by tightening the inner nut 5 and the outer nut 6. Based on the same principle, a passive rotation function between the prosthetic forearm and the prosthetic upper arm is realized. This adds an important degree of rotational freedom to the prosthesis, which was originally just a fixed rigid body, allowing patients with upper limb amputations to manipulate the prosthesis more flexibly.

[0039] Furthermore, the passive wrist joint rotation damping mechanism can also be used as a rotating display stand. The connecting base plate 4 is connected to the standard prosthesis socket interface 9 as a fixed base for the rotating display stand, while the stud rotation plate 1 can serve as a rotating platform to place exhibits. The wrist joint rotation damping mechanism can also be applied to the display of other physical models, making the model more closely resemble the real object while also helping visitors understand the number and specific location of rotational degrees of freedom within the physical model. Therefore, the application scenarios for this wrist joint rotation mechanism are very broad.

[0040] The present invention also provides a myoelectric prosthetic hand, the myoelectric prosthetic hand including a quick-change connector and the passive wrist joint rotation damping mechanism suitable for the myoelectric prosthetic hand, the quick-change connector being connected to the mechanism.

[0041] The present invention also provides a prosthetic limb, the prosthetic limb comprising a myoelectric prosthetic hand, a quick-change connector, a prosthetic receiving cavity, and a passive wrist joint rotation damping mechanism as described above for the myoelectric prosthetic hand, wherein the quick-change connector is connected to the myoelectric prosthetic hand, and the mechanism is connected to the quick-change connector and the prosthetic receiving cavity respectively.

[0042] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A passive wrist joint rotation damping mechanism, characterized in that: The passive wrist joint rotation damping mechanism includes a stud rotating plate, a first convex washer, a second convex washer, a connecting base plate, and a nut. The stud rotating plate includes a cylinder and a stud connected to the cylinder. The stud rotating plate also has a receiving hole that passes through the cylinder and the stud, through which wires transmitting current and signals in the myoelectric prosthesis hand pass to connect with a control board inside the prosthesis receiving cavity. The end of the stud away from the cylinder passes sequentially through the first convex washer, the second convex washer, and the connecting base plate before being threaded to the nut. The convex surface of the first convex washer contacts the convex surface of the second convex washer. The nut, by tightening with the stud, presses against the connecting base plate, causing the first and second convex washers to exert a compressive force in the vertical direction. The friction generated by the compression between the first and second convex washers forms the rotational damping torque of the passive wrist joint rotation damping mechanism. By overcoming the friction, the passive wrist joint rotation damping mechanism can be rotated, thereby achieving passive rotation. The structure of the first convex washer is the same as that of the second convex washer. The first convex washer is conical, including a large end face, a small end face, and a fan-shaped surface connecting the large end face and the small end face, wherein the small end face is a convex plane. A groove is provided at one end of the connecting base plate to accommodate the first and second convex washers.

2. The passive wrist joint rotation damping mechanism as described in claim 1, characterized in that: The cylinder has four protrusions evenly distributed around its circumference, and each protrusion has a first threaded hole. The passive wrist joint rotation damping mechanism is connected to the quick-change connector of the myoelectric prosthetic hand through the first threaded hole.

3. The passive wrist joint rotation damping mechanism as described in claim 1, characterized in that: Multiple spaced stripes are formed on the convex plane, and the stripes are used to increase the friction between the first convex pad and the second convex pad.

4. The passive wrist joint rotation damping mechanism as described in any one of claims 1-3, characterized in that: The bottom surface of the groove has a central hole that penetrates the connecting base plate. The central hole is used for the stud to pass through and provides wiring space for the control signal line and power line of the myoelectric prosthetic hand.

5. The passive wrist joint rotation damping mechanism as described in claim 4, characterized in that: The connecting base plate is also provided with four evenly distributed second threaded holes on its circumference, and the connecting base plate is threadedly connected to the prosthesis receiving cavity through the four second threaded holes.

6. A myoelectric prosthetic hand, characterized in that: The myoelectric prosthetic hand includes a quick-change connector and a passive wrist joint rotation damping mechanism as described in any one of claims 1-5, wherein the quick-change connector is connected to the passive wrist joint rotation damping mechanism.

7. A prosthetic limb, characterized in that: The prosthetic limb includes a myoelectric prosthetic hand, a quick-change connector, a prosthetic socket, and a passive wrist joint rotation damping mechanism as described in any one of claims 1-5. The quick-change connector is connected to the myoelectric prosthetic hand, and the passive wrist joint rotation damping mechanism is connected to the quick-change connector and the prosthetic socket.

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