KR20140005279U - A reconfigurable ankle exoskeleton device - Google Patents

Abstract

The present invention relates to a ungrounded, reconfigurable, parallel mechanism based force feedback exoskeleton device for a human ankle. The main use of the device is for balanced / proprioceptive sensory trainer, but exoskeleton devices can also be utilized to accommodate range of motion (RoM) / enhancement exercises. These devices are also used for cervical articulation exercises.

Description

Reconfigurable ankle exoskeleton device {A RECONFIGURABLE ANKLE EXOKELETON DEVICE}

The present invention relates to ungrounded, reconfigurable, parallel mechanism based, force feedback exoskeleton devices for human ankles. The main use of the device is for balanced / proprioception proprioception trainer, but an exoskeleton device can also be utilized to provide motion range (RoM) / reinforcement movements. These devices are also used for metatarsophalangeal joint movements.

The goal of rehabilitation is to restore the body, sensory and nerve abilities of patients who are injured by illness or injury. Ankle rehabilitation is generally required after sprained ankles, one of the most common injuries in sport and everyday life [1]. Loss of functional ability at the ankle, ability to withstand weight, and joint stability is also experienced after secondary congenital malformations of cerebral vascular disease and secondary nerve damage to seizures. To reinforce the muscles to withstand the weight, to promote the better perception of the joint position (proprioceptive sense), to ensure the perfection of the nerve, and to ensure dynamic To restore balance, physical therapy exercises are inevitable.

Rehabilitation of ankle injuries is generally treated as three sequential exercise steps [2], [3]. The movements in the initial stage first enable the complete RoM of the joint and then focus on strengthening the ankle muscles. Once the required RoM and flexibility are achieved, the muscles are not painful enough and are strong enough to tolerate some weight, and an intermediate stage of therapy can be initiated, concentrating on improving the proprioceptive sensory ability through the use of static balancing movements . In the final stages of therapy, more advanced dynamic balance exercises are practiced.

Conventional rehabilitation devices used to assist in physical therapy include ankle rehabilitation pumps and elastic bands for strengthening and stretching exercises; It is a simple manual device, such as foam rollers and wobble boards for proprietary aqueous sensory and balance motions. RoM exercises are usually performed manually by a therapist. While these types of equipment are simple and cost-effective, these conventional devices collect measurements of the patient's progress, monitor the patient's history for re-evaluation, customize, It is insufficient to acquire interactive treatment protocols. Therapeutic specialists are required to have these devices to concentrate fully on the patient during exercise and to convey the physical burden to exercise therapy.

Today, rehabilitation exercises are performed with the help of robotic devices. Aids to repetitive, physically related rehabilitation exercises using robotic devices can not only eliminate the physical burden of exercise therapy for therapists, but also reduce the cost associated with the application. Moreover, robot-mediated rehabilitation therapy can be used to provide quantitative measures of patient progress and to implement customized, interactive treatment protocols.

The beneficial effects of robotic assisted rehabilitation protocols have been demonstrated during conventional treatments through clinical trials in [4]. Recognizing the need for robotic assisted rehabilitation devices for ankle physical therapy, several designs have so far been proposed. Girone et al proposed a force feedback interface, called Rutgers ankle, based on the Stuart platform [5]. In [6], a virtual reality-based interactive training protocol was conducted using Rutgers ankle for orthopedic rehabilitation. The system has been further studied in [7] and [8] through several case studies. Home-centric remote ankle rehabilitation was mentioned in [9], while in [10] the system was extended to dual Stuart platform configurations for use in gait simulation and rehabilitation.

In [11], Dai et al proposed another robotic device to treat sprained ankle injuries. Unlike the Stewart platform design, the device goes to a degree of freedom (DoF) to include the orientation workspace of the human ankle. The static analysis presented in this reference emphasizes the importance of utilizing a central strut to achieve greater rigidity from the device. In [12], Agrawal et al. Proposed an ankle-foot shaping device for robot assisted rehabilitation and presented kinematic analysis and control of the proposed mechanism. Similarly, in [13], anklebots have been proposed by Roy et al. To help restore ankle function. The device can also be used to measure ankle rigidity, a strong bodily factor for locomotion.

Syrseloudis and Emiris studied the translational and rotational RoM of human ankles and feet through experiments in humans and the parallel triangular mechanism with a continuous additional axis of rotation is the most appropriate kinematic design to follow the foot kinematics associated with human ankles I concluded. In [15] Yoon and Ryu proposed a footpad device based on a hybrid four DoF parallel mechanism and presented a kinematic analysis of the new device. In [3] and [16], this study was extended to allow reconfiguration of the device to support several distinct motion modes.

Therefore, the purpose of this invention is to provide a device with a reconfigurable design. Its implementation is simple and the device can be fabricated by assembling commonly available components. By its reconfigurable capability, the device allows both range-of-motion RoM / enhancement motions and balance / proprioceptive sensory motions.

According to one embodiment of the present invention, the device may include a whole range of complexities of the human ankle for RoM / strengthening exercises. The device can support human weight during balance / proprioceptive sensory movements. Torsional joint motion can also be achieved through the reconfigurable design of the base plate.

According to one embodiment of the present invention, the device can be utilized as a clinical measurement tool. Ankle joint level movements, forces, and impedances can be determined to help diagnose.

According to one embodiment of the present invention, the device is ergonomic and takes into account the entire operating range of the human ankle. The device is lightweight and wearable; Therefore, it is portable. The device is intrinsically safe by the choice of its actuators.

According to one embodiment of the present invention, the device has higher control performance than similar devices by its parallel kinematic structure and optimized bandwidth.

According to one embodiment of the present invention, the device supports the complicated movements of the foot and is not limited to a single degree of freedom, as is the case with many existing designs.

According to one embodiment of the present invention, the device can be programmed to guide, assist, or block the patient during physical therapy and is implemented with a computer system. The level of auxiliary and resistance is software adjustable. The device can also be programmed to measure ankle joint parameters, such as ankle tension and impedance.

The aspects of the device according to the present invention include rehabilitation robots, robot assisted rehabilitation, physiotherapy devices, force feedback exoskeletons, tactile interfaces for treatment, clinical measurement devices, ankle rehabilitation systems, ankle orthopedic devices, Rehabilitation devices for treatment, devices for evaluating ankle function, and determination of ankle impedance.

Are included herein.

1 is a perspective view of a device;
Figure 2 is a side view of a device with a 3UPS configuration;
Figure 3 is a perspective view of a device operating with a 3RPS mechanism;
Figure 4 is a perspective view of the device when operating in a 3UPS mechanism (the intermediate link represents the human foot and ankle);
5 is a perspective view of the joint member used in the device in a non-locking position;
Figure 6 is a perspective view of the joint member used in the device in the locked position;
Figure 7 is a block diagram of a robust position control device with a reaction torque observer;

The following detailed description of the preferred embodiments is purely exemplary and in no way restricts the invention, its application, or uses.

Ankle therapy and measurement exoskeleton device (1)

A moving platform 2 against which the operator ' s feet rest,

A base platform 3 facing the legs of the operator,

A connecting member 4 for connecting the base platform 3 and the moving platform 2,

.

The exoskeleton device 1 further includes a joint member 5 for connecting the connecting member 4 to the base platform 3. With the aid of the joint member 5, the exoskeleton device 1 can separately support two different types of motion, RoM / strengthening movements and balance / proprioceptive sensory movements. The joint member 5 may alternatively be other modes. In a preferred embodiment of the present invention, it is switched between a universal joint and a revolute joint.

In a preferred embodiment of the present invention, the connecting member 4 is connected to the moving platform 2 using spherical joints.

The ankle joint may be formed as a series of kinematic chains of space having two revolute joints (RR), an upper ankle joint and a subtalar joint. The upper ankle joint supports a rotating dorsiflexion / plantar flexion movement while the subtalia joint supports a rotating supination / pronation movement. Abduction / adduction rotation is a complex movement that includes both inversion / pronation and abduction / adduction components.

The kinematic chain used in the preferred embodiment of the present invention is a closed kinematic chain (parallel mechanism). The closed kinematic chain is used as an exoskeleton and it is supported in consideration of the natural movements of human joints when the operator wears the device 1. [ Closed kinematic chains provide compact designs with high rigidity and low inertia. Closed kinematic chains can be placed on or grounded on parts of the mechanism that experience low acceleration.

The closed kinematic chain used in the present invention can be used with at least two different mechanisms with the aid of the joint member 5. By this fact, the device 1 obtains a reconfigurable characteristic. In a preferred embodiment of the present invention it can be used separately from each other in a 3UPS (universal, prismatic, spherical) and 3RPS (revolute, prism, spherical) mechanism.

In a preferred embodiment of the present invention, the joint member 5 is a reconfigurable joint that may optionally be used in unlocked or locked positions. At the non-locking position, the reconfigurable joint 5 is free to rotate about the two axes A, B. The first axis A is tangential to the base plate 3 while the second axis B is perpendicular to the base plate 3. [ When the joint 5 is unlocked, a series of revolute joints function as a universal joint that rotates about the desired axes. When the second joint axis B is a lock, the reconfigurable joint 5 is restricted to function as a revolute joint and can rotate freely only around the first axis A. Thus, the reconfigurable joint 5 allows the 3UPS mechanism to be reconfigured with the 3RPS mechanism, and vice versa.

The connecting member 4 basically comprises a drive unit 6 and a moving element 7. The driving unit 6 can apply a necessary force on the moving element 7 and can move the moving element 7. In a preferred embodiment of the present invention, the drive unit 6 is an electric motor, while the moving element 7 is at least one extendable link.

When a closed kinematic chain is used as the 3UPS mechanism, the reconfigurable joint 5 is in the unlocked position, i.e. rotates freely about the desired axes A and B, and acts as a universal joint. In addition, the legs of the operator act as central links of the mechanism, i.e. the ankle of the operator becomes the absence of the mechanism. In the preferred embodiment of the present invention, the mechanism is a symmetrical 3UPS mechanism and the universal joint 5 and the spherical joints are spaced 120 [deg.] Along the periphery of the base platform 3 and the moving platform 2. When worn by the user, the 3UPS mechanism mounted on the human ankle has two degrees of freedom (DoF) corresponding to the coupled motion of the moving platform 2 relative to the fixed base platform 3 . The length of the extendable links 7 is operated to control this DoF. The moving platform 2 has a distance z from the base platform 3 and does not have translational motion transverse to the vertical axis through the base 2. [ Even when the operator is fully passive, the two DoF 3UPS mechanisms have three working joints; Therefore, it is a redundant mechanism. This redundancy can be exploited to increase the effective working space of the device 1 since the resolution can be realized when the device 1 approaches singularities within the workspace. have.

When a closed kinematic chain is used as the 3RPS mechanism, the reconfigurable joint 5 is in the locked position, i.e. the rotational movement of the joint 5 relative to the second axis B is prevented. The reconfigurable joint 5 acts as a revolute joint and its axis of rotation is directed along the tangents of the base platform 3. The base platform 3 is mounted to the upper mid-calf of the leg via a manual revolute joint to allow internal / external rotations of the foot. In the preferred embodiment of the present invention, the mechanism is a symmetrical 3RPS mechanism and the revolute joints 5 and the spherical joints are spaced 120 [deg.] Along the periphery of the base platform 3 and the moving platform 2. The 3RPS mechanism has three DoFs corresponding to the height z. Extendable links 7 are operated to control this DoF. The mobile platform 2 has non-specificities for limited values of the revolute joint angles and limited translational motion traversing the vertical axis through the base 3.

When the closed kinematic chain is in the 3UPS mode, the device 1 can be utilized as a RoM / enriched motion device, while when in the 3RPS mode it can be utilized as a balanced / proprioceptive sensory motor device .

The joints between the exoskeleton device 1 and the actuators are designed as elastic to ensure small joint alignment defects and fabrication defects and to ensure safety. The elasticity allows the relative movement of the limb of the human to the device 1 when the kinematics of the device 1 collide with the natural movement of the ankle.

In one embodiment of the present invention, the weight of device 1 is distributed over upper mid-calves and upper legs using tight straps around the knee.

In another embodiment of the present invention, the weight of the device 1 can be distributed to the body by hanging the device 1 from the shoulder of the operator.

The exoskeleton device 1 further comprises a control unit (not shown in the figures) and at least two sensors (not shown in the figures). One of the sensors measures the length of the connecting member (4) while the second sensor measures the amount of axial rotation of the joint member (5). The measured data of the elements are processed by the control unit to calculate the configuration of the device 1 and to measure the forces acting on it (1). In particular, the forward kinematics of the device 1 are used to calculate the configuration of the mobile platform 2, while the kinematics of the device 1 are software It is used in conjunction with an applied reaction torque observer.

To measure the ankle parameters, the link (1) lengths of the kinematic chain must be known to coincide with the rotational axes of the revolute joints. The determination of the operator's bone length is relatively simple, as ankle x-ray images can be studied to achieve reasonably accurate measurements. However, since the motion of the ankle depends on the size and orientation of the foot bones and the shape of the articulated surfaces, the determination of the rotational axes is not straightforward. Only the course measurements of joint axes can be obtained for studying x-ray images. Measurements of more accurate joint axes are desirable for studying ankle motion and such measurements may be made possible by data collected in the exoskeleton.

Given a good measure of bone length, the rotational axes of the revolute joints of the human ankle preferably collect position data from the three rotational sensors and extensible links 7 located on the joint member 5, Can be determined by instructing the operator to perform free RoM motions. Once the data is available, the configuration level forward kinematics of the 3UPS mechanism is resolved for the mobile platform 2 configurations at each instant. Once the foot configurations are recorded, the constituent level inverse kinematics of the two link RR manipulators with unrecognized revolute joint axes (representing the human ankle) are determined by the amount of rotation about these axes, Axis.

Given the kinetic characteristics of the exoskeleton device 1 and the configuration and motion level advances and inverse kinematics of the combined 3UPS-RR system (the exoskeleton associated with the human ankle), a reaction torque observer is provided A rigid position control device may be implemented to characterize the dynamic characteristics of the ankle. In particular, with a robust position control device, the exoskeleton device 1 can command the ankle to draw the desired trajectory, while disturbance forces can be measured during this exercise by the unknown dynamics of the ankle . In the control device implementation, the known kinetic forces of the exoskeleton device 1 are added to the system in a feed forward fashion to ensure that the disturbances acting on the system are due solely to the ankle's unknown dynamics. Under such control, the forces commanded by the control device act against the unconstrained dynamics of the ankle. Thus, assuming that actuator forces can be mapped to joint torques in the ankle and all other disturbances are relatively small, these torques provide a measurement close to the actual joint torques by ankle dynamics.

The exoskeleton device 1 may perform passive, active, assist, and resistance exercise modes. Virtual tunnels and force fields within these tunnels can be implemented to allow safe practice with assistance or resistance.

Since the device 1 in the 3UPS configuration allows all possible movements of the ankle within its full range, the device 1 can be used for clinical measurements. First, the device can be used to determine the range of motion of the patient. As the patient moves on his / her ankle, the device can record and measure the time history (trajectory) of such movement. Given a time history of the measured movement, it is possible to determine how quickly the patient completes the motion, the amount of error associated with the reference trajectory, and how flat / periodic these movements are. Since the dynamics of the device 1 are known, it is also possible to show the measured configuration changes with respect to the rotation of the ankle joint. This possibility allows measurement of the direction, velocity and smoothness of the ankle joint motion. The coordination and synergy of the joint motion can also be detected from these measurements.

Disturbance forces due to the non-known kinetics of the ankle can be measured during this exercise, using a robust position control device and by instructing the exoskeleton device 1 to draw the desired trajectory, as described above. These forces can also be expressed in joint torques in the ankle using ankle dynamics.

This measurement technique can be used to determine the maximum joint torques that can affect the tone and impedance of the patient's ankle in any configuration of the ankle. In particular, if the gains of the robust position control device are set to stay in some reference configuration and the patient is required to exert a maximum torque on his / her ankle joints, then the disturbance forces acting on the control device Can be expressed in joint torques to measure human ankle joint torques for the axes. Finally, given a pre-specified reference locus for a robust position controller, the joint torques can be measured at each instant and the relationship between joint rotation and joint torques can be measured to determine the ankle impedance and / Can be used.

In other embodiments of the present invention, ungrounded, wearable, and reconfigurable ankle care and measurement exoskeleton devices may be combined with virtual reality games.

The detailed description of the present invention is intended to be purely exemplary, and variations that do not depart from the gist of the present invention are intended to be within the scope of the present invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

1: exoskeleton device
2: Mobile Platform
3: Base platform
4:
5: joint member
6: drive unit
7: Moving element
references:
[1] H. Tropp and H. Alaranta, Sports Injuries: Basic Principles of Prevention and Treatment, Proprioceptive Sensory and Adjustment Training in Injury Prevention. Oxford, 1993
[2] D. Hung, M. Kennedy, A. Rowland, JD Purdy, and M. Yampolsky, "Anchor Rehabilitation: Evidence-Based Approach", Vanderbilt Rehabilitation Services.
[3] J. Yoon, J. Ryu, and K. Lim, "A New Reconfigurable Ankle Rehabilitation Robot for Various Exercise Modes", Robot System Journal (now Field Robot Journal), vol. 22, no. 1, pp. 15-33, 2006.
[4] R. Ekkelenkamp, P. Veltink, S. Stramigioli, and H van der Kooij, "Evaluation of Virtual Model Control for Selection of Walking Functions Using Exoskeleton", Rehabilitation Robotics, 2007. ICORR2007. IEEE 10th International Conference on, pp. 693-699, June 2007.
[5] M. Girone, G. Burdea, and M. Bouzit, "Rehabilitation Interface of Rutgers Ankle Orthopedic Surgery", in Proceedings of the ASME Haptics Symposium, vol. 67, 1999, pp. 305-312.
[6] M. Girone, G. Burdea, and M. Bouzit, V. Popescu, and J. Deutsch, "Orthopedic Rehabilitation Using Rutgers Ankle Interface" in Proceedings of Virtual Reality Meets Medicine 2000, pp. 89-95.
[7] JE Deutsch, J. Latonio, G. Burdea, and R. Boian, "Rehabilitation of Musculoskeletal Injuries Using Rutgers Ankle Tactile Interface: Reports of Three Cases", in Proceedings of Eurohaptics 2001, July 1- 4, 2001, pp. 93-98.
[8] JE Deutsch, J. Latonio, GC Burdea, and R. Boian, "Post-Stroke Rehabilitation with Rutgers Ankle System: A Case Study", Presence: Teleoper. Virtual Environ., Vol. 10, no. 4, pp. 416 ^ 130, 2001.
[9] M. Girone, G. Burdea, M. Bouzit, V. Popescu, and JE Deutsch, "Stuart platform-based systems for ankle communication rehabilitation", Autonomous Robots, vol. 10, no. 2, pp. 203-212, 2001.
[10] RF Boian, M. Bouzit, GC BURDEA, J. Lewis, and JE Deutsch, "Dual Stuart Platform Mobility Simulator", in Proceedings of the ICORR 2005, 9th International Conference on Rehabilitation Robotics, 2005, pp. 550-555.
[11] JS Dai, T. Zhao, and C. Nester, "Stiffness Analysis of Sprained Ankle Physical Therapy and Robotic Rehabilitation Devices Based on Mechanism Integration," Auton. Robots, vol. 16, no. 2, pp. 207-218, 2004.
[12] A. Agrawal, S. Banala, S. Agrawal, and S. Binder-Macleod, "Design of a Two-Degree-of-Freedom Ankle-Horn for Robot Rehabilitation," Rehabilitation Robotics, 2005. ICORR 2005. 9th International Conference on, pp. 41-44, June-1 July 2005.
[13] A. Roy, H. Krebs, S. Patterson, T. Judkins, I. Khanna, L. Forrester, R. Macko, and N. Hogan, "Measurement of Human Ankle Rigidity Using Anchor Bots," Rehabilitation Robot Engineering, 2007. ICORR 2007. IEEE 10th International Conference on, pp. 356-363, June 2007.
[14] CE Syrseloudis, IZ Emiris, CN Maganaris, and TE Lilas, "Design Framework for Simple Robot Ankle Evaluation and Rehabilitation Devices", Medical Biotechnology Society, 2008. EMBS 2008. 30th Annual International Conference of the IEEE, pp. 4310-4313, AUG. 2008.
[15] J. Yoon and J. Ryu, "Application of the Hydro-4Dof Parallel Mechanism with Two Platforms to a New Family and Footpad Device", Journal of Robotic Systems, vol. 22, no. 5, pp. 287-298, 2005.
[16] ---, "A New Reconstructable Ankle / Foot Rehabilitation Robot", Robotics and Automation, 2005. ICRA 2005. Proceedings of the 2005 IEEE International Conference on, pp. 2290-2295, April 2005.

Claims (16)

A base platform that abuts an operator's leg;
A moving platform for mating with the feet of the operator;
A connecting member connecting the base platform and the moving platform; And
A joint member connecting the connecting member to the moving platform;
And a non-earthed, wearable, and reconfigurable ankle care and measurement exoskeleton device. The method according to claim 1,
Wherein the exoskeleton device is capable of supporting two different motion types: RoM / strengthening movements and balance / proprioceptive sensory movements separately from each other. 3. The method according to claim 1 or 2,
Characterized in that the joint member is a reconfigurable joint and the reconfigurable joint at the unlocked position is free to rotate about the two axes, the first axis is tangential to the base plate and the second axis is perpendicular to the base plate An ungrounded ankle therapy and measurement exoskeleton device. The method of claim 3,
Characterized in that when said reconfigurable joint is non-locking, a series of revolute joints acts as a universal joint rotating about said preferred axes. The method of claim 3,
Wherein when the second joint axis is a lock, the reconfigurable joint is restricted to function as a revolute joint so that it is free to rotate only about the uni-axial. 6. The method according to any one of claims 1 to 5,
Wherein the reconfigurable joint allows a 3UPS mechanism in which the device is used as a RoM / enhanced motion device to be reconfigured with a 3RPS mechanism in which the device is used as a balanced / proprietary sensory motion device, and vice versa. An ankle care and measurement exoskeleton device. The method according to claim 6,
Characterized in that when the device is used in a 3UPS mechanism, the reconfigurable joint is in a non-locking position and acts as a universal joint and the leg of the operator acts as the center links of the mechanism. . The method according to claim 6,
Wherein the reconfigurable joint is in the locked position when the device is used as a 3RPS mechanism and acts as a revolute joint and the rotational axis is directed along the tangents of the base platform. 9. The method according to any one of claims 1 to 8,
Wherein the connecting member comprises a drive unit and a moving element. ≪ Desc / Clms Page number 14 > 10. The method according to any one of claims 1 to 9,
A control unit, and at least two sensors. 11. The method according to any one of claims 1 to 10,
Wherein the device is capable of performing passive, active, assist, and resistance exercise modes. ≪ Desc / Clms Page number 19 > 12. The method of claim 11,
Wherein the virtual tunnels and the field of forces within the tunnels are provided with the auxiliary or resistive modes to enable secure practice. 13. The method of claim 12,
Ungrounded ankle therapy and measurement exoskeleton devices combined with virtual reality games. 14. The method according to any one of claims 1 to 13,
≪ / RTI > further comprising a rigid position control device having a torque observer. A method of using an ungrounded ankle care and measurement exoskeleton device according to any one of claims 10 to 14 for performing clinical measurements. Joint configuration, movement speed, trajectory, trajectory error, smoothness of movement, range of motion, coordination and cooperation, maximum joint torques in any configuration, joint torque during tracing of any trajectory, ankle tension and impedance 15. An unbalanced ankle care and measurement exoskeleton device according to claim 15.

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