A three-degree-of-freedom ankle rehabilitation robot

Abstract

A three-degree-of-freedom ankle rehabilitation robot includes a horizontal turntable and a two-degree-of-freedom rotating pedal. The two-degree-of-freedom rotating pedal employs a spherical parallel mechanism and is mounted on the horizontal turntable by screws. The invention also provides a specific implementation structure for the horizontal turntable and the two-degree-of-freedom rotating pedal. This invention provides a three-degree-of-freedom ankle rehabilitation robot, aiming to improve the safety, compliance, and effectiveness of ankle rehabilitation training, while reducing the control difficulty of the parallel structure.

Description

Technical Field

[0001] This invention relates to the fields of robotics, rehabilitation medicine, and medical devices, and more specifically, to an ankle rehabilitation robot for patients with ankle injuries. Background Technology

[0002] The ankle joint is the most complex force-bearing center in the human body. When standing still, the ankle joint bears the pressure equivalent to twice the body weight; when standing on the forefoot, the pressure is equivalent to three times the body weight; and during weight-bearing propulsion, the pressure is equivalent to five times the body weight. Therefore, ankle injuries are one of the most common diseases in clinical orthopedics. If injuries are not treated promptly and effectively, they can seriously affect a patient's daily life and, in severe cases, lead to sequelae.

[0003] Traditional ankle rehabilitation methods vary depending on the situation. For minor ankle sprains, patients should follow the RICE principle; for severe ligament tears, surgery is necessary, followed by postoperative rehabilitation training assisted by a physician. Common ankle rehabilitation methods include ankle pump exercises and device-assisted training. Professional physician assistance is essential for ankle rehabilitation training; otherwise, ineffective training or even secondary injury may occur.

[0004] Introducing robots into ankle rehabilitation training systems can significantly improve the effectiveness of ankle joint exercise training. When using robots for assisted rehabilitation training, patients will frequently interact with the robot, which places high demands on the robot's operational compliance, safety, and effectiveness. Summary of the Invention

[0005] To overcome the shortcomings in the safety and effectiveness of existing robots in ankle rehabilitation training, this invention provides a three-degree-of-freedom ankle rehabilitation robot, which aims to improve the safety, compliance and effectiveness of ankle rehabilitation training, while reducing the control difficulty of parallel structures.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A three-degree-of-freedom ankle joint rehabilitation robot includes a horizontal turntable and a two-degree-of-freedom rotating pedal, wherein the two-degree-of-freedom rotating pedal adopts a spherical parallel mechanism and is mounted on the horizontal turntable.

[0008] Furthermore, the two-degree-of-freedom rotary pedal includes a support assembly, a pedal assembly, a left / right drive linkage assembly, a driven linkage assembly, and a geared motor assembly. The left / right drive linkage assembly is mounted on the drive shaft of the support assembly via a flat key, and the driven linkage assembly is mounted on the drive shaft of the support assembly via a bearing. The pedal assembly forms a revolute pair with the driven linkage assembly and the left / right drive linkage assembly, respectively. The two sets of geared motor assemblies are mounted on both sides of the support assembly via flat keys and screws.

[0009] Furthermore, the horizontal turntable includes a fixed base, a turntable, a transmission vertical shaft assembly, and a worm gear reducer motor assembly. The worm gear reducer motor assembly is mounted on the fixed base; the transmission vertical shaft assembly is connected to the worm gear reducer motor assembly via a flat key.

[0010] Furthermore, the transmission vertical shaft assembly includes a vertical shaft housing, a vertical shaft, a planar thrust bearing, a first bearing middle cover, and a turntable connector. The worm gear reducer motor assembly includes a worm gear reducer and a motor. The vertical shaft housing is mounted on the worm gear reducer using array screws. The vertical shaft is mounted inside the vertical shaft housing via the planar thrust bearing and is axially positioned using the first bearing middle cover. The turntable connector is mounted on the end of the vertical shaft using a flat key and fixed with set screws. The turntable is mounted on the turntable connector using array screws, and the turntable can rotate horizontally with the vertical shaft.

[0011] In this invention, the horizontal turntable serves as the supporting component of the two-degree-of-freedom rotating pedal, providing the pedal with a third degree of rotational freedom.

[0012] Furthermore, the support assembly is composed of various support parts. The driven linkage assembly includes a drive shaft, a driven rod, a driven cam, a second bearing cover, and a front guide shaft. The support assembly is fixed to the turntable by screws. The drive shaft is symmetrically arranged on the main support via bearings, all of which can perform high-speed transmission. The driven cam is mounted on the drive shaft via bearings and is axially positioned by the second bearing cover. The driven rod connects the symmetrically arranged driven cams via array screws, so that a pair of driven cams move synchronously. The front guide shaft is mounted on the driven rod by screws.

[0013] Furthermore, each of the left / right drive linkage assemblies includes a drive wheel, a drive linkage, a spherical linkage, and a linkage shaft. The drive wheel is mounted on the drive shaft via a flat key; the drive linkage is mounted on the drive wheel via screws, and the drive linkage has a certain bending angle; the linkage shaft is mounted on the drive linkage via screws; one end of the spherical linkage is mounted on the drive shaft via a pair of bearings, and the other end is connected to the rear guide shaft via bearings.

[0014] Furthermore, the pedal assembly includes a pedal, a pedal connector, a motion link, and a rear guide shaft. The pedal is mounted on the motion link via the pedal connector; the rear guide shaft is mounted on the motion link via screws; the motion link forms a revolute joint with the front guide shaft, and the rear guide shaft forms a revolute joint with the spherical link; the position of the front / rear guide shafts can determine the posture of the pedal.

[0015] The technical concept of this invention is as follows:

[0016] In this invention, the axes of the vertical axis, drive axis, connecting rod axis, and front / rear guide axis are extended to intersect at a fixed point above the pedal, so that the spherical connecting rod and the pedal always rotate around that point in three degrees of freedom.

[0017] This invention uses a horizontal turntable to support a two-degree-of-freedom rotating pedal. The horizontal turntable consists of a fixed base and the turntable itself. The fixed base remains stable during machine operation. The worm gear reducer motor transmits driving force to the turntable through a vertical shaft, allowing the turntable to rotate around the vertical shaft on a horizontal plane, indirectly driving the pedal to rotate on the horizontal plane.

[0018] The two-degree-of-freedom rotary pedal controls its posture by controlling the positions of the front and rear guide shafts. A geared motor transmits power to the drive wheels via a drive shaft; one end of the drive linkage connects to the drive wheel, and the other end connects to the linkage shaft; a spherical connecting rod forms a revolute joint with both the linkage shaft and the rear guide shaft, with their axes intersecting at a fixed point; one end of the driven cam is mounted on the drive shaft, and the other end connects to the front guide shaft, allowing the front guide shaft to rotate in the machine's sagittal plane; the pedal forms a revolute joint with the front guide shaft and is connected to the rear guide shaft via screws; thus, the two-degree-of-freedom rotation of the pedal can be controlled by adjusting the rotation angle of a pair of drive wheels.

[0019] The beneficial effects of this invention are mainly reflected in the following aspects: 1) During the operation of this invention, the pedal always rotates around a fixed point above, which coincides with the patient's ankle joint, avoiding unnecessary displacement of the patient's ankle joint during rehabilitation and improving the safety and effectiveness of the structural rehabilitation process. 2) This invention reduces the difficulty of structural control and ensures structural reliability by partially decoupling the parallel structure. Attached Figure Description

[0020] Figure 1 This is the overall structural diagram of the present invention.

[0021] Figure 2 This is a schematic diagram of the horizontal turntable structure of the present invention.

[0022] Figure 3 This is a schematic diagram of the two-degree-of-freedom rotary pedal structure of the present invention.

[0023] Figure 4 yes Figure 3 A schematic diagram of the bottom structure of the two-degree-of-freedom rotating pedal of the present invention.

[0024] In the diagram, 100-two-degree-of-freedom rotary pedal, 200-horizontal turntable, 101-drive wheel, 102-drive shaft, 103-drive connecting rod, 104-connecting rod shaft, 105-spherical connecting rod, 106-small bracket, 107-large bracket, 108-motor, 109-right-angle reducer, 110-motor connector, 111-driven cam, 112-driven long rod, 113-pedal, 114-motion connecting rod, 115-front guide shaft, 116-rear guide shaft, 117-pedal connector, 201-turntable, 202-vertical shaft, 203-turntable connector, 204-worm gear reducer, 205-vertical shaft housing, 206-motor, 207-fixed base. Detailed Implementation

[0025] The present invention will now be further described with reference to the accompanying drawings.

[0026] Reference Figures 1-4 A three-degree-of-freedom ankle rehabilitation robot includes a two-degree-of-freedom rotating pedal 100 and a horizontal turntable 200. The two-degree-of-freedom rotating pedal 100 is mounted on the horizontal turntable 200 and can be fixed together by screws.

[0027] Reference Figure 2 The horizontal turntable 200 includes a turntable 201, a vertical shaft 202, a turntable connector 203, a vertical shaft housing 205, a worm gear reducer 204, a motor 206, and a fixed base 207. The motor 206 is mounted on the worm gear reducer 204, and the worm gear reducer 204 is mounted on the fixed base 207, and they can be fixed together by screws. The vertical shaft housing 205 is mounted on the worm gear reducer 204 by array screws. The vertical shaft 202 is mounted inside the vertical shaft housing 205 by bearings and is connected to the worm gear reducer 204 by a flat key. The turntable connector 203 is mounted on the shaft end of the vertical shaft 202 by a flat key and fixed with set screws. The turntable 201 is mounted on the turntable connector 203 by array screws. Thus, the motor 206 can transmit power through the vertical shaft 202 to control the rotation of the turntable 201 on the horizontal plane.

[0028] Reference Figure 3 and Figure 4The two-degree-of-freedom rotary pedal 100 includes a drive wheel 101, a drive shaft 102, a drive link 103, a link shaft 104, a spherical link 105, a small bracket 106, a large bracket 107, a motor 108, a right-angle reducer 109, a motor connector 110, a driven cam 111, a driven long rod 112, a pedal 113, a motion link 114, a front guide shaft 115, a rear guide shaft 116, and a pedal connector 117. The small bracket 106 and the large bracket 107 are assembled into a bracket assembly by screws and mounted on the turntable 201 by screws. The drive shaft 102 is symmetrically arranged on the large bracket 107 by bearings, enabling high-speed transmission. The motor connector 110 is mounted on the side of the large bracket 107. The right-angle reducer 109 is mounted on the motor connector 110 by array screws, with the motor 108 mounted at its input end and the output end connected to the drive shaft 102. The driven cam 111 is mounted on the motor connector 110 by bearings. The following components are mounted on the drive shaft 102: a driven long rod 112 connects symmetrically arranged driven cams 111 via array screws, synchronizing the movement of the pair of driven cams 111; a front guide shaft 115 is mounted on the driven long rod 112 via screws; a drive wheel 101 is mounted on the drive shaft 102 via a flat key; a drive connecting rod 103 is mounted on the drive wheel 101 via screws, and the drive connecting rod 103 has a certain bending angle; a connecting rod shaft 104 is mounted on the drive connecting rod 103 via screws; one end of a spherical connecting rod 105 forms a revolute joint with the drive shaft 102 and the rear guide shaft 116 respectively; a pedal 113 is mounted on a motion connecting rod 114 via a pedal connector 117; the rear guide shaft 116 is mounted on the motion connecting rod 114 via screws; the motion connecting rod 114 forms a revolute joint with the front guide shaft 115; thus, the motor 108 can control the two-degree-of-freedom rotation of the pedal 113 by controlling the rotation angle of the pair of drive wheels 101.

[0029] The working process of this embodiment is as follows:

[0030] When using this ankle rehabilitation robot for ankle rehabilitation training, follow these steps: 1) Open the host computer program and complete the initialization; 2) The patient sits in the seat, adjusts to a comfortable sitting position, and places their feet on the machine's pedals; 3) Use straps to bind the patient's feet so that they cannot move freely; 4) Input the rehabilitation trajectory into the host computer program and control the motor to assist the patient in ankle rehabilitation training.

[0031] This ankle rehabilitation robot can be used for repetitive training of movements such as dorsiflexion / plantarflexion and inversion / eversion during ankle rehabilitation. Passive training strategies, active training strategies, and a hybrid active-passive training strategy can be employed during training. During rehabilitation, the patient's ankle joint remains stationary while the pedal rotates around the patient's ankle joint in three degrees of freedom, ensuring the safety and effectiveness of ankle joint movement training.

[0032] The embodiments described in this specification are merely examples of implementations of the inventive concept and are for illustrative purposes only. The scope of protection of this invention should not be considered limited to the specific forms described in these embodiments; rather, it extends to equivalent technical means conceived by those skilled in the art based on the inventive concept.

Claims

1. A three-degree-of-freedom ankle joint rehabilitation robot, characterized in that, The robot includes a horizontal turntable and a two-degree-of-freedom rotating pedal. The two-degree-of-freedom rotating pedal adopts a spherical parallel mechanism and is mounted on the horizontal turntable. The two-degree-of-freedom rotary pedal includes a support assembly, a pedal assembly, a left / right drive linkage assembly, a driven linkage assembly, and a geared motor assembly. The left / right drive linkage assembly is mounted on the drive shaft of the support assembly via a flat key. The driven linkage assembly is mounted on the drive shaft of the support assembly via a bearing. The pedal assembly forms a revolute pair with the driven linkage assembly and the left / right drive linkage assembly, respectively. The two sets of geared motor assemblies are mounted on both sides of the support assembly via flat keys and screws. Small and large brackets are assembled into a bracket assembly by screws. The two bracket assemblies are mounted on the turntable by screws. The driven linkage assembly includes a drive shaft, a driven long rod, a driven cam, a second bearing cover, and a front guide shaft. The bracket assembly is fixed to the turntable by screws. The drive shaft is symmetrically arranged on the two large brackets by bearings, both of which can perform high-speed transmission. The driven cam is mounted on the drive shaft by bearings and is axially positioned by the second bearing cover. The driven long rod connects the symmetrically arranged driven cams by array screws, so that the movement of a pair of driven cams is synchronized. The front guide shaft is mounted on the driven long rod by screws. The left / right drive linkage assembly includes a drive wheel, a drive linkage, a spherical linkage, and a linkage shaft. The drive wheel is mounted on the drive shaft via a flat key. The drive linkage is mounted on the drive wheel via screws and has a certain bending angle. The linkage shaft is mounted on the drive linkage via screws. One end of the spherical linkage is mounted on the drive shaft via a pair of bearings, and the other end is connected to the rear guide shaft of the pedal assembly via a bearing. The pedal assembly includes a pedal, a pedal connector, a motion link, and a rear guide shaft. The pedal is mounted on the motion link via the pedal connector. The rear guide shaft is mounted on the motion link via screws. The rear guide shaft forms a revolute joint with the spherical link, and the motion link forms a revolute joint with the front guide shaft. The positions of the front and rear guide shafts determine the posture of the pedal.

2. The three-degree-of-freedom ankle joint rehabilitation robot as described in claim 1, characterized in that, The horizontal turntable includes a fixed base, a turntable, a transmission vertical shaft assembly, and a worm gear reducer motor assembly. The worm gear reducer motor assembly is mounted on the fixed base, and the transmission vertical shaft assembly is connected to the worm gear reducer motor assembly via a flat key.

3. The three-degree-of-freedom ankle joint rehabilitation robot as described in claim 2, characterized in that, The transmission vertical shaft assembly includes a vertical shaft housing, a vertical shaft, a planar thrust bearing, a first bearing cover, and a turntable connector. The worm gear reducer motor assembly includes a worm gear reducer and a motor. The vertical shaft housing is mounted on the worm gear reducer using array screws. The vertical shaft is mounted inside the vertical shaft housing via the planar thrust bearing and is axially positioned using the first bearing cover. The turntable connector is mounted on the end of the vertical shaft using a flat key and secured with set screws. The turntable is mounted on the turntable connector using array screws, and the turntable can rotate horizontally with the vertical shaft.

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