Kinematic Analysis of an Exoskeleton-Based Robot for Elbow and Wrist Rehabilitation (original) (raw)
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Modeling and development of an exoskeleton robot for rehabilitation of wrist movements
2010
As a stage toward a complete upper-arm motion assisted exoskeleton robot (i.e., 7DOF) this paper focused on the development of a 2DOF exoskeleton robot to rehabilitate and to ease wrist joint movements. To perform essential daily activities the movement of shoulder, elbow, and wrist play a vital role and proper functioning of the upper-limb is essential. We therefore have been developing an exoskeleton robot (ExoRob) to rehabilitate and to ease upper limb motion. The proposed 2DOF ExoRob is designed to be worn on the lateral side of the forearm in order to provide naturalistic movements (i.e., flexion/extension and radial/ulnar deviation) of the wrist joint. This paper also focuses on the modeling and control of the proposed ExoRob. A kinematic model of ExoRob has been developed based on modified Denavit-Hartenberg notations. In dynamic simulations of the proposed ExoRob, a nonlinear sliding mode control technique is employed, where trajectory tracking that corresponds to typical rehab (passive) exercises has been carried out to evaluate the performances of the developed model and controller. Moreover experiments were carried out with PID controller to further evaluate the developed model regard to trajectory tracking. Simulated and experimental results show that the controller is able to maneuver the ExoRob efficiently to track the desired trajectories, which in this case consisted in passive arm movements. Such movements are typically used in rehabilitation and could be performed very efficiently with the developed ExoRob and the controller.
Design of a robot-assisted exoskeleton for passive wrist and forearm rehabilitation
Mechanical Sciences, 2019
This paper presents a new exoskeleton design for wrist and forearm rehabilitation. The contribution of this study is to offer a methodology which shows how to adapt a serial manipulator that reduces the number of actuators used on exoskeleton design for the rehabilitation. The system offered is a combination of end-effectorand exoskeleton-based devices. The passive exoskeleton is attached to the end effector of the manipulator, which provides motion for the purpose of rehabilitation process. The Denso VP 6-Axis Articulated Robot is used to control motion of the exoskeleton during the rehabilitation process. The exoskeleton is designed to be used for both wrist and forearm motions. The desired moving capabilities of the exoskeleton are flexion-extension (FE) and adduction-abduction (AA) motions for the wrist and pronation-supination (PS) motion for the forearm. The anatomical structure of a human limb is taken as a constraint during the design. The joints on the exoskeleton can be locked or unlocked manually in order to restrict or enable the movements. The parts of the exoskeleton include mechanical stoppers to prevent the excessive motion. One passive degree of freedom (DOF) is added in order to prevent misalignment problems between the axes of FE and AA motions. Kinematic feedback of the experiments is performed by using a wireless motion tracker assembled on the exoskeleton. The results proved that motion transmission from robot to exoskeleton is satisfactorily achieved. Instead of different exoskeletons in which each axis is driven and controlled separately, one serial robot with adaptable passive exoskeletons is adequate to facilitate rehabilitation exercises.
A robot for wrist rehabilitation
2001
In 1991, a novel robot named MIT-MANUS was introduced as a test bed to study the potential of using robots to assist in and quantify the neuro-rehabilitation of motor function. It proved an excellent fit for the rehabilitation of shoulder and elbow of stroke patients with results in clinical trials showing a reduction of impairment in these joints. The greater reduction in impairment was limited to the group of muscles exercised. This suggests a need for additional robots to rehabilitate other degrees of freedom. This paper outlines the mechanical design of a robot for wrist rehabilitation.
—Rehabilitation is the best cure method for patients who suffer physical disability in their upper limbs organ. Maintaining the intensity of practice during treatment, is the main factor that makes the robots the best option for rehabilitation, because robots do not get tired and do the practices with constant intensity under supervision of the doctor. Two main categories of rehabilitation robots are End-Effector base rehabilitation robot and wearable rehabilitation robots. Nowadays, the investigations are made on wearable robots. Wearable robots are divided into three types of Exoskeleton robots, Prosthetic robots and Orthotic robot. In this paper a new structure for an Orthotic wearable robot is developed to human wrist rehabilitation. This structure has an automatic base that provides using of robot for both hands. This robot has three degree of freedom that is similar to human wrist joint. Conceptual design, mechanical design, kinematics and dynamic analysis and multiple impedance control are implemented in this paper.
Wrist Rehabilitation with Manipulator to Perform Passive and Active Exercises
Lékař a technika - Clinician and Technology
The paper characterizes basic dysfunctions and diseases of a human wrist as well as describes the mechanics and pathomorphology of the human hand. The radial-carpal joint was analyzed in terms of his ranges of motion. The results of the analysis, i.e. the number of degrees of freedom for a free hand, are included. The concept of manipulator construction for optimal rehabilitation of the wrist was developed. Expected effects of the exercises, which can be implemented on the designed manipulator, were also described. A comparative analysis of other appliances supporting the rehabilitation of the human upper limb were presented. The main purpose of the designed manipulator was to gain full control of implementation of exercises performed by the patient and to archive and precisely track the progress in the rehabilitation. An important feature of the designed manipulator is its versatility enabling its use for: exercises of both hands (left and right) with the repetitive movements, choo...
Ergonomic design of a wrist robot
International Journal of Intelligent Computing and Cybernetics, 2014
2014),"Integrated vision-based system for efficient, semi-automated control of a robotic manipulator", International Abstract Purpose -The purpose of this paper is to propose a method to avoid hyperstaticity and eventually reduce the magnitude of undesired force/torques. The authors also study the influence of hyperstaticity on human motor control during a redundant task. Design/methodology/approach -Increasing the level of transparency of robotic interfaces is critical to haptic investigations and applications. This issue is particularly important to robotic structures that mimic the human counterpart's morphology and attach directly to the limb. Problems arise for complex joints such as the wrist, which cannot be accurately matched with a traditional mechanical joint. In such cases, mechanical differences between human and robotic joint cause hyperstaticity (i.e. over-constrained) which, coupled with kinematic misalignment, leads to uncontrolled force/torque at the joint. This paper focusses on the prono-supination (PS) degree of freedom of the forearm. The overall force and torque in the wrist PS rotation is quantified by means of a wrist robot. Findings -A practical solution to avoid hyperstaticity and reduce the level of undesired force/torque in the wrist is presented. This technique is shown to reduce 75 percent of the force and 68 percent of the torque. It is also shown an over-constrained mechanism could alter human motor strategies. Practical implications -The presented solution could be taken into account in the early phase of design of robots. It could also be applied to modify the fixation points of commercial robots in order to reduce the magnitude of reaction forces and avoid changes in motor strategy during the robotic therapy. Originality/value -In this paper for the first time the authors study the effect of hyperstaticity on both reaction forces and human motor strategies.
Exoskeleton robot for rehabilitation of elbow and forearm movements
18th Mediterranean Conference on Control and Automation, MED'10, 2010
To perform essential daily activities the movement of shoulder, elbow, and wrist play a vital role and therefore proper functioning of upper-limb is very much essential. We therefore have been developing an exoskeleton robot (ExoRob) to rehabilitate and to ease upper limb motion. Toward to make a complete (i.e., 7DOF) upper-arm motion assisted robotic exoskeleton this paper focused on the development of a 2DOF exoskeleton robot to rehabilitate the elbow and forearm movements. The proposed 2DOF ExoRob is supposed to be worn on the lateral side of forearm and provide naturalistic range movements of elbow (flexion/extension) and forearm (pronation/supination) motions. This paper also focuses on the modeling and control of the proposed ExoRob. A kinematic model of the ExoRob has been developed based on modified Denavit-Hartenberg notations. Nonlinear sliding mode control technique is employed in dynamic simulation of the proposed ExoRob, where trajectory tracking that corresponds to typical rehab (passive) exercises has been carried out to evaluate the effectiveness of the developed model and controller. Simulated results show that the controller is able to maneuver the ExoRob efficiently to track the desired trajectories, which in this case consisted in passive arm movements. These movements are widely used in rehab therapy and could be performed efficiently with the developed ExoRob and the controller.
Design and control of system for elbow rehabilitation: Preliminary findings
Advances in Clinical and Experimental Medicine, 2018
Background. The use of an exoskeleton elbow is considered an effective treatment in several pathologies, including post-stroke complications, traumatic brain injury (TBI) and spinal cord injury (SCI), as well as in patients with neurodegenerative disorders. The effectiveness of rehabilitation is closely linked to a suitably chosen therapy. The treatment can be performed only by specialized personnel, significantly supported with the use of automated devices. Objectives. The aim of this study was to present a novel exoskeleton for elbow rehabilitation without a complicated control system. Material and methods. Single-degree-of-freedom (SDOF) solution in constructing the prototype of an elbow exoskeleton for rehabilitation purposes has been applied. The simplicity of the actuation mechanism was set as one of the priorities in the design; thus, a single-axis stepper motor with a controller was found to be adequate for providing a reliable and precise source of motion for the exoskeleton. Results. Technological development may provide novel solutions, such as an exoskeleton-a wearable, external structure which supports or (in selected applications) even replaces the muscle actuation in the patient. The reported advantages of the proposed exoskeleton reflect current state-of-the-art. The proposed control strategy relies on closed-loop position control, performance, low manufacturing cost, and predicted performance in a rehabilitation scenario. All these factors play an important role in establishing the directions for further research, e.g., an integrated force sensor in the device, measurements of torque interactions on the elbow joint, and assessment and response to an overload of articulation. Conclusions. This study suggests not only the clinical but also the possible economic and logistical advantages offered by the portability of the system, and its effective support for therapists applying an elbow exoskeleton.
State-of-the-Art Robotic Devices for Wrist Rehabilitation: Design and Control Aspects
IEEE Transactions on Human-Machine Systems, 2020
Robot assisted physical therapy of the upper limb is becoming popular among the rehabilitation community. The wrist is the second most complicated joint in the upper limb after shoulder in terms of degrees of freedom. Several robotic devices have been developed during the past three decades for wrist joint rehabilitation. Intensive physical therapy and repetitive selfpractice, with objective measurement of performance could be provided by using these wrist rehabilitation robots at a low cost. There has been an increasing trend in the development of wrist rehabilitation robots to provide safe and customized therapy according to the disability level of patients. The mechanical design and control paradigms are two active fields of research undergoing rapid developments in the field of robot assisted wrist rehabilitation. The mechanical design of these robots could be divided into the categories of end-effector based robots and wearable robotic orthoses. The control for these wrist rehabilitation robots could also be divided into the conventional trajectory tracking control mode and the Assist-as-Needed control mode for providing customized robotic assistance. This paper presents a review of the mechanical design and control aspects of wrist rehabilitation robots. Experimental evaluations of these robots with healthy and neurologically impaired are also discussed along with the future directions of research in the design and control domains of wrist rehabilitation robots.
International Journal of Robotic Research, 2008
This paper presents the design, control and performance of a high fidelity four degree-of-freedom wrist exoskeleton robot, RiceWrist, for training and rehabilitation. The RiceWrist is intended to provide kinesthetic feedback during the training of motor skills or rehabilitation of reaching movements. Motivation for such applications is based on findings that show robot-assisted physical therapy aids in the rehabilitation process following neurological injuries. The exoskeleton device accommodates forearm supination and pronation, wrist flexion and extension and radial and ulnar deviation in a compact parallel mechanism design with low friction, zero backlash and high stiffness. As compared to other exoskeleton devices, the RiceWrist allows easy measurement of human joint angles and independent kinesthetic feedback to individual human joints. In this paper, joint-space as well as task-space position controllers and an impedance-based force controller for the device are presented. The kinematic performance of the device is characterized in terms of its workspace, singularities, manipulability, backlash and backdrivability. The dynamic performance of RiceWrist is characterized in terms of motor torque output, joint friction, step responses, behavior under closed loop set-point and trajectory tracking control and display of virtual walls. The device is singularity-free, encompasses most of the natural workspace of the human joints and exhibits low friction, zero-backlash and high manipulability, which are kinematic properties that characterize a highquality impedance display device. In addition, the device displays fast, accurate response under position control that matches human actuation bandwidth and the capability to display sufficiently hard contact with little coupling between controlled degrees-of-freedom.