A multi-degree-of-freedom bionic foot rehabilitation robot device

Abstract

The application discloses a multi-degree-of-freedom bionic foot rehabilitation robot device, which comprises an outer frame, a four-section bionic foot sole plate and a parallel driving mechanism. The four-section bionic foot sole plate is connected through a rotating shaft hinge and a slider and slide rod structure, and simulates the biomechanical movement of the rear foot area, the middle foot area, the front foot area and the toe bone area of a human foot. The parallel driving mechanism adjusts the posture of each foot sole plate section, realizes the multi-degree-of-freedom movement and deformation compensation of the ankle joint and the foot, and is wearable on the foot and suitable for the rehabilitation training of patients with lower limb motor dysfunction.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of rehabilitation medical devices, and relates to a multi-degree-of-freedom bionic foot rehabilitation robot device. BACKGROUND

[0002] As an important auxiliary device for patients with lower limb motor dysfunction, the foot rehabilitation robot has a wide application in gait training of patients with stroke, spinal cord injury and the like. The traditional foot rehabilitation device is usually composed of a fixed support and a simple hinge, and the foot of the patient needs to be passively followed by the mechanical trajectory movement. However, the human foot, as one of the most complex biomechanical structures of the human body, contains 28 bones, 33 joints and multiple muscle synergies, and its movement involves multi-degree-of-freedom coordinated movement such as ankle dorsiflexion / planter flexion, inversion / eversion, forefoot pronation / supination and dynamic deformation of the arch.

[0003] In the prior art, the mainstream lower limb exoskeleton and foot rehabilitation device generally adopts a rigid foot plate design, simplifies the foot into a single rigid plate, and only designs 1-2 degrees of freedom flexion and extension movement of the ankle joint, which cannot simulate the arch deformation and the activity of the metatarsophalangeal joint, resulting in abnormal foot pressure distribution during training and easily causing complications such as plantar fasciitis. Since the forefoot and the hindfoot are fixedly connected, the effect of forefoot pronation / supination on gait stability during walking is ignored.

[0004] In addition, biomechanical studies on arch deformation show that the arch length changes by 2-3 cm in normal gait, and the existing rigid foot plate design forces the arch to maintain a static shape, which not only limits the activation of the foot muscles, but also may cause the arch ligament to relax. Therefore, there is an urgent need for a bionic rehabilitation device that can reproduce multi-segment coordinated movement of the foot and reduce mechanical impact. SUMMARY

[0005] In order to overcome the problems of the single rigid foot plate of the existing foot rehabilitation robot, such as lack of degrees of freedom, and inability to simulate multi-segment coordinated movement of the foot, the application provides a multi-degree-of-freedom bionic foot rehabilitation robot device, which realizes multi-dimensional movement of the foot and ankle joint and dynamic deformation compensation of the arch through the coordinated design of the four-segment bionic foot plate and the parallel driving mechanism.

[0006] To achieve the above purpose, the technical scheme adopted by the application is as follows:

[0007] A multi-degree-of-freedom bionic foot rehabilitation robot device, comprising a device outer frame, a four-segment bionic foot plate and a parallel driving mechanism; the four-segment bionic foot plate and the parallel driving mechanism are located inside the outer frame, a flexible shoe is arranged above the four-segment bionic foot plate, and the parallel driving mechanism drives the four-segment bionic foot plate together and acts on the flexible shoe, thereby pulling the foot to move.

[0008] Furthermore, the four-segment bionic foot plate includes a toe plate area, a forefoot plate area, a midfoot plate area, and a posteriorfoot plate area connected in sequence. The toe plate area and the forefoot plate area are connected by a single-degree-of-freedom hinge shaft one, the forefoot plate area and the midfoot plate area are connected by a single-degree-of-freedom hinge shaft two, and the midfoot plate area and the posteriorfoot plate area are connected by a two-degree-of-freedom slider mechanism.

[0009] Furthermore, the two-degree-of-freedom slider mechanism includes a linear slider guide rail, an optical axis slider, and a slider support. The linear slider guide rail is fixed to the bottom of the midfoot area of ​​the foot plate, and the slider support is fixed to the bottom of the rearfoot area of ​​the foot plate. One end of the optical axis slider is hinged to the slider support through a slider pin to achieve single-degree-of-freedom rotation, and the other end passes through the linear slider guide rail and slides freely along the axial direction.

[0010] Furthermore, the hinge of the second single-degree-of-freedom hinge axis is parallel to the direction of the foot arch.

[0011] Furthermore, the outer frame of the device includes an upper fixed plate and a lower fixed plate, which are fixedly connected by a support column, and the four-segment bionic foot plate is located above the lower fixed plate.

[0012] Furthermore, the parallel drive mechanism includes at least seven sets of linear actuators, each set of linear actuators including a motor, a lead screw mechanism, and a universal ball joint mechanism; wherein: the motor is fixed above the upper fixed plate; one end of the lead screw mechanism passes through the upper fixed plate and is fixedly connected to the output shaft of the motor via a coupling, and the other end is fixedly connected to the universal ball joint mechanism; the end of the universal ball joint mechanism away from the lead screw mechanism is connected to the four-segment bionic foot plate. Furthermore, the lead screw mechanism includes a lead screw and a lead screw sleeve, the lead screw being a ball screw, and the lead screw is embedded in the lead screw sleeve, forming a helical transmission engagement with the lead screw sleeve.

[0013] Furthermore, the universal ball joint mechanism includes a universal ball joint and a ball joint fixing frame; the ball joint fixing frame is fixed to the four-segment bionic foot plate, the universal ball joint includes a ball head and a housing part, the ball head is fixedly connected to the ball joint fixing frame, and the housing part is fixedly connected to the end of the lead screw sleeve away from the lead screw.

[0014] Furthermore, when the lead screw rotates around its own axis under the drive of the motor, it drives the lead screw sleeve to move up and down along the axis of the lead screw through the helical transmission cooperation with the lead screw sleeve, and then drives the four-segment bionic foot plate to move at the corresponding position through the universal ball joint mechanism.

[0015] Furthermore, the upper fixing plate has a leg hole in the center area for inserting the foot through the leg hole into the device, and a leg strap is provided above the leg hole for securing it.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] This invention reproduces multi-degree-of-freedom foot movements through the synergistic effect of a four-segment bionic foot plate and a parallel drive mechanism, including forefoot pronation / supination, phalanx flexion / extension, and arch deformation. Compared with traditional single-degree-of-freedom devices, the movement dimensions are significantly improved, and the natural gait is more closely matched. Parameters such as screw travel and foot plate size can be adjusted according to the patient's morphological parameters and rehabilitation stage. Attached Figure Description

[0018] Figure 1 This is an overall schematic diagram of the multi-degree-of-freedom bionic foot rehabilitation robot device in an embodiment of the present invention.

[0019] Figure 2 This is a schematic view of the foot plate of the multi-degree-of-freedom bionic foot rehabilitation robot device in an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the foot plate of the foot rehabilitation device of the multi-degree-of-freedom bionic foot rehabilitation robot device in an embodiment of the present invention.

[0021] Figure 4 This is a flowchart illustrating the motion of the multi-degree-of-freedom bionic foot rehabilitation robot device in an embodiment of the present invention.

[0022] In the diagram, the components are: 1. Upper fixing plate; 2. Leg strap; 3. Motor; 4. Lead screw; 5. Lead screw sleeve; 6. Support column; 7. Flexible shoe; 8. Universal ball joint; 9. Ball joint fixing frame; 10. Four-section bionic foot plate; 11. Lower fixing plate; 12. Toe bone area of ​​foot plate; 13. Forefoot area of ​​foot plate; 14. Midfoot area of ​​foot plate; 15. Rearfoot area of ​​foot plate; 16. Single-degree-of-freedom hinge pivot one; 17. Single-degree-of-freedom hinge pivot two; 18. Linear slider guide rail; 19. Optical axis slide rod; 20. Slide rod pin; 21. Slide rod bracket. Detailed Implementation

[0023] The multi-degree-of-freedom bionic foot rehabilitation robot device of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1As shown, a multi-degree-of-freedom bionic foot rehabilitation robot device includes an outer frame, a four-segment bionic foot plate 10, and a parallel drive mechanism; the four-segment bionic foot plate 10 and the parallel drive mechanism are located inside the outer frame. A flexible shoe 7 is provided above the four-segment bionic foot plate 10. The parallel drive mechanism jointly drives the four-segment bionic foot plate 10 and acts on the flexible shoe 7, thereby tractioning foot movement.

[0025] like Figure 2 As shown, the four-segment bionic foot plate 10 includes a toe bone area 12, a forefoot area 13, a midfoot area 14, and a posterior foot area 15 connected in sequence, corresponding to the toe bone area, forefoot area, midfoot area, and posterior foot area of ​​the human foot, respectively.

[0026] like Figure 3 As shown, the plantar plate phalangeal region 12 and the plantar plate forefoot region 13 are connected by a single-degree-of-freedom hinge pivot 16, enabling flexion and extension movements of the metatarsophalangeal joint. The plantar plate forefoot region 13 and the plantar plate midfoot region 14 are connected by a single-degree-of-freedom hinge pivot 17. The hinge of the single-degree-of-freedom hinge pivot 17 is parallel to the arch of the foot, allowing the forefoot segment to rotate freely around its axis, simulating arch deformation.

[0027] The midfoot area 14 and rearfoot area 15 of the sole plate are connected by a two-degree-of-freedom sliding block mechanism. This mechanism includes a linear slider guide rail 18, a linear guide rod 19, and a slider support 21. The linear slider guide rail 18 is fixed to the bottom of the midfoot area 14, and the slider support 21 is fixed to the bottom of the rearfoot area 15. One end of the linear guide rod 19 is hinged to the slider support 21 via a slider pin 20, allowing for single-degree-of-freedom rotation around this hinge point; the other end passes through the linear slider guide rail 18 and can slide freely along its axial direction. Through this combination of rotational and sliding degrees of freedom, two-degree-of-freedom relative motion is achieved between the midfoot area 14 and the rearfoot area 15 of the sole plate.

[0028] The device of this invention provides motion assistance in a fixed position through an outer frame support. The outer frame includes an upper fixing plate 1 and a lower fixing plate 11. The upper fixing plate 1 has a leg hole in its central area for the foot to pass through and enter the device. A leg strap 2 is provided above the leg hole to secure the wearer's leg. The upper fixing plate 1 and the lower fixing plate 11 are fixedly connected by a support column 6. The four-segment bionic foot plate 10 and other mechanisms are located above the lower fixing plate 11, enabling multi-degree-of-freedom movement of the foot.

[0029] The parallel drive mechanism includes at least seven sets of linear actuators, each set of linear actuators including a motor 3, a lead screw mechanism and a universal ball joint mechanism; wherein: the motor 3 is fixed above the upper fixed plate 1; one end of the lead screw mechanism passes through the upper fixed plate 1 and is fixedly connected to the output shaft of the motor 3 through a coupling, and the other end is fixedly connected to the universal ball joint mechanism; the end of the universal ball joint mechanism away from the lead screw mechanism is connected to the four-segment bionic foot plate 10.

[0030] The lead screw mechanism includes a lead screw 4 and a lead screw sleeve 5. The lead screw 4 is a ball screw, and the lead screw 4 is embedded in the lead screw sleeve 5 and forms a helical transmission engagement with the lead screw sleeve 5.

[0031] The universal ball joint mechanism includes a universal ball joint 8 and a ball joint fixing frame 9; the ball joint fixing frame 9 is fixed on the four-segment bionic foot plate 10, the universal ball joint 8 includes a ball head and a shell part, the ball head is fixedly connected to the ball joint fixing frame 9, and the shell part is fixedly connected to the end of the lead screw sleeve 5 away from the lead screw 4.

[0032] When the lead screw 4 rotates around its own axis under the drive of the motor 3, it drives the lead screw sleeve 5 to move up and down along the axis of the lead screw 4 through the helical transmission cooperation with the lead screw sleeve 5. Then, through the universal ball joint mechanism, it drives the corresponding position of the four-segment bionic foot plate 10 to achieve the upward and downward movement.

[0033] In one specific embodiment of the present invention, the parallel drive mechanism includes seven sets of linear actuators, utilizing a seven-degree-of-freedom parallel drive mechanism to achieve multi-degree-of-freedom drive. Three sets of linear actuators are symmetrically distributed on both sides and the rear of the posterior region 15 of the plantar plate. The ends of the lead screws are connected to the drive point in the posterior region of the plantar plate via universal joints. The movement of the posterior foot is controlled collaboratively by adjusting the stroke of the three sets of linear actuators. Three sets of linear actuators are arranged in the anterior region 13 of the plantar plate. The ends of the lead screw mechanisms are connected to corresponding positions in the anterior region via universal joints, driving forefoot pronation / supination and arch height adjustment. One independent linear actuator is vertically connected to the end of the phalanx region 12 of the plantar plate, driving flexion and extension movements of the phalanx via a lead screw.

[0034] like Figure 4 As shown, during actual operation, the device of the present invention can send signals to control the motor 3 through the control driver in the external electrical part. The motor 3 drives the lead screw 4 to rotate, and the lead screw sleeve 5 converts the rotational motion into axial motion, which drives the universal ball head 8 to move and act on the four-segment bionic foot plate 10, thereby realizing multi-degree-of-freedom movements of the foot such as vertical translation, pitching and rolling. A displacement sensor can be installed on the lead screw or the position control can be achieved by using the encoder built into the motor as the feedback signal source of the controller.

[0035] The working process and principle of the device of the present invention are as follows:

[0036] Step 1: Wearing and Initialization

[0037] After the system starts, the motor rotates, lowering the four-segment bionic footplate to its lowest point to complete the zero-point calibration of each linear actuator, and then controls the four-segment bionic footplate to rise to the preset initial position. The user passes their lower leg through the leg hole in the center of the upper fixing plate 1, allowing the foot to naturally fit into the flexible shoe 7. The foot is secured by the straps on the flexible shoe, ensuring close contact between the foot and each segment of the four-segment bionic footplate. The leg is further secured by the leg straps 2 to prevent movement deviation.

[0038] Step 2: Drive and Control Execution

[0039] The control core issues commands through the motion controller to control the motors in the seven sets of linear actuators. Each linear actuator drives the lead screw sleeve to generate axial linear displacement through the rotation of the lead screw.

[0040] Each linear actuator's end is connected to a four-segment bionic footplate via a universal ball joint, enabling it to adapt to angles in three dimensions. During the drive process, the interaction between the components is as follows:

[0041] Flexion and extension movements of the phalangeal region: Axial displacement in the vertical direction is provided by an independent linear actuator, which drives the phalangeal region to rotate around the first single-degree-of-freedom hinge through the universal ball joint, thereby simulating the flexion and extension of the metatarsophalangeal joint.

[0042] Forefoot pronation / supination: The combined motion of three sets of linear actuators in the forefoot area changes the direction of their action on the forefoot area, causing the forefoot area to rotate around the single-degree-of-freedom hinge 2, thereby realizing forefoot pronation and supination, which is one of the keys to foot stability regulation.

[0043] Longitudinal dynamic changes in the midfoot-hindfoot segment: A two-degree-of-freedom slider-slider mechanism located at the midfoot-hindfoot connection provides sliding compensation capabilities in both the anteroposterior and vertical directions. When the three sets of actuators in the hindfoot segment adjust their stroke asynchronously, they drive the slider to generate longitudinal stretching or compression, simulating the dynamic compression and rebound process of the arch of the foot during weight-bearing and take-off phases, thus achieving biomimetic compensation of the arch of the foot.

[0044] Multi-angle adjustment of the heel: Three sets of linear actuators are spatially symmetrically distributed around the heel area, and can achieve three-way adjustment of the area in terms of rise, pitch and roll through coordinated action to meet the needs of complex gait phases such as heel strike and lift-off.

[0045] The above description is merely a preferred embodiment of the present invention. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solutions of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A multi-degree-of-freedom bionic foot rehabilitation robot device, characterized in that, It includes an outer frame, a four-segment bionic foot plate (10), and a parallel drive mechanism; the four-segment bionic foot plate (10) and the parallel drive mechanism are located inside the outer frame, and a flexible shoe (7) is provided above the four-segment bionic foot plate (10). The parallel drive mechanism jointly drives the four-segment bionic foot plate (10) and acts on the flexible shoe (7), thereby traction of foot movement; The four-segment bionic foot plate (10) includes a foot plate phalangeal region (12), a foot plate anterior region (13), a foot plate mid-foot region (14), and a foot plate posterior region (15) connected in sequence. The foot plate phalangeal region (12) and the foot plate anterior region (13) are connected by a single-degree-of-freedom hinge shaft one (16). The foot plate anterior region (13) and the foot plate mid-foot region (14) are connected by a single-degree-of-freedom hinge shaft two (17). The foot plate mid-foot region (14) and the foot plate posterior region (15) are connected by a two-degree-of-freedom slider mechanism. The two-degree-of-freedom slider mechanism includes a linear slider guide rail (18), an optical axis slider (19), and a slider bracket (21). The linear slider guide rail (18) is fixed to the bottom of the midfoot area (14) of the sole plate, and the slider bracket (21) is fixed to the bottom of the posterior foot area (15) of the sole plate. One end of the optical axis slider (19) is hinged to the slider bracket (21) through a slider pin (20) to achieve single-degree-of-freedom rotation, and the other end passes through the linear slider guide rail (18) and slides freely along the axial direction. The hinge of the single-degree-of-freedom hinge pivot (17) is parallel to the arch of the foot. The parallel drive mechanism includes seven sets of linear actuators, each set of linear actuators including a motor (3), a lead screw mechanism and a universal ball joint mechanism; three sets of linear actuators are symmetrically distributed on both sides and the back side of the plantar plate rear area (15), three sets of linear actuators are arranged in the plantar plate front area (13), and one set of independent linear actuators is vertically connected to the end of the plantar plate phalanx area (12).

2. The multi-degree-of-freedom bionic foot rehabilitation robot device according to claim 1, characterized in that, The outer frame includes an upper fixing plate (1) and a lower fixing plate (11), which are fixedly connected by a support column (6). The four-segment bionic foot plate (10) is fixed above the lower fixing plate (11).

3. The multi-degree-of-freedom bionic foot rehabilitation robot device according to claim 2, characterized in that, The motor (3) is fixed above the upper fixed plate (1); one end of the lead screw mechanism passes through the upper fixed plate (1) and is fixedly connected to the output shaft of the motor (3) through a coupling, and the other end is fixedly connected to the universal ball joint mechanism; the end of the universal ball joint mechanism away from the lead screw mechanism is connected to the four-segment bionic foot plate (10).

4. The multi-degree-of-freedom bionic foot rehabilitation robot device according to claim 3, characterized in that, The lead screw mechanism includes a lead screw (4) and a lead screw sleeve (5). The lead screw (4) is a ball screw, and the lead screw (4) is embedded in the lead screw sleeve (5) and forms a helical transmission cooperation with the lead screw sleeve (5).

5. The multi-degree-of-freedom bionic foot rehabilitation robot device according to claim 4, characterized in that, The universal ball joint mechanism includes a universal ball joint (8) and a ball joint fixing frame (9); the ball joint fixing frame (9) is fixed on the four-segment bionic foot plate (10); the universal ball joint (8) includes a ball head and a shell part; the ball head is fixedly connected to the ball joint fixing frame (9); and the shell part is fixedly connected to the end of the lead screw sleeve (5) away from the lead screw (4).

6. The multi-degree-of-freedom bionic foot rehabilitation robot device according to claim 4, characterized in that, When the lead screw (4) rotates around its own axis under the drive of the motor (3), it drives the lead screw sleeve (5) to move up and down along the axis of the lead screw (4) through the helical transmission with the lead screw sleeve (5), and then drives the four-section bionic foot plate (10) to move at the corresponding position through the universal ball joint mechanism.

7. The multi-degree-of-freedom bionic foot rehabilitation robot device according to claim 2, characterized in that, The upper fixing plate (1) has a leg hole in the center area for inserting the foot through the leg hole into the device. A leg strap (2) is provided above the leg hole for fixing.

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