Mohammad Habibur Rahman

Development of a whole arm wearable robotic exoskeleton for rehabilitation and to assist upper limb movements

To assist physically disabled people with impaired upper limb function, we have developed a new 7-DOF exoskeleton-type robot named Motion Assistive Robotic-Exoskeleton for Superior Extremity (ETS-MARSE) to ease daily upper limb movements and to provide effective rehabilitation therapy to the superior extremity. The ETS-MARSE comprises a shoulder motion support part, an elbow and forearm motion support part, and a wrist motion support part. It is designed to be worn on the lateral side of the upper limb in order to provide naturalistic movements of the shoulder (vertical and horizontal flexion/extension and internal/external rotation), elbow (flexion/extension), forearm (pronation/supination), and wrist joint (radial/ulnar deviation and flexion/extension). This paper focuses on the modeling, design, development, and control of the ETS-MARSE. Experiments were carried out with healthy male human subjects in whom trajectory tracking in the form of passive rehabilitation exercises (i.e., pre-programmed trajectories recommended by a therapist/clinician) were carried out. Experimental results show that the ETS-MARSE can efficiently perform passive rehabilitation therapy.

Development and control of a wearable robot for rehabilitation of elbow and shoulder joint movements

We have been developing an exoskeleton robot (ExoRob) for assisting daily upper limb movements (i.e., shoulder, elbow and wrist). In this paper we have focused on the development of a 2DOF ExoRob to rehabilitate elbow joint flexion/extension and shoulder joint internal/external rotation, as a step toward the development of a complete (i.e., 3DOF) shoulder motion assisted exoskeleton robot. The proposed ExoRob is designed to be worn on the lateral side of the upper arm in order to provide naturalistic movements at the level of elbow (flexion/extension) and shoulder joint internal/external rotation. 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 novel nonlinear sliding mode control technique with exponential reaching law and computed torque control technique is employed, 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 drive the ExoRob efficiently to track the desired trajectories, which in this case consisted in passive arm movements. Such movements are used in rehabilitation and could be performed very efficiently with the developed ExoRob and the controller. Experiments were carried out to validate the simulated results as well as to evaluate the performance of the controller.

Modeling and development of an exoskeleton robot for rehabilitation of wrist movements

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.

Adaptation Strategy for the 3DOF Exoskeleton for Upper-Limb Motion Assist

Exoskeletons are expected to be used as wearable haptic devices and power assist robot systems. We have been studying exoskeletons to assist the human motion in daily activity and rehabilitation. The EMG (electromyogram), which directly reflects the human motion intention, has been used to control the exoskeleton without any special control equipment. This paper presents a strategy that realizes the effective adaptation of the EMG-based exoskeleton controller (i.e., robot-human interface) to any persons.

Development of a 4DoFs exoskeleton robot for passive arm movement assistance

Proper functioning of the upper limbs is important to manage essential activities of daily living. To provide assistance and rehabilitation to individuals with upper limb dysfunction due to conditions such as stroke or spinal cord injuries, we have developed a 4DoFs exoskeleton robot (ExoRob). The ExoRob was designed to be worn on the lateral side of the upper arm, to conform to a naturalistic range of movement for the shoulder and elbow joints. This paper focuses on the modelling, design, development, and control of the ExoRob. Experiments were carried out with healthy human subjects where trajectories tracking in the form of passive rehabilitation exercises were performed. Further experiments were carried out with the master exoskeleton arm (mExoArm, an upper-limb prototype exoskeleton arm) where subjects operate the mExoArm (like a joystick) to maneuver the ExoRob to provide passive rehabilitation. Experimental results show that the ExoRob can effectively perform passive rehabilitation exercises.

Exoskeleton robot for rehabilitation of elbow and forearm movements

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.

DYNAMIC MODELING AND EVALUATION OF A ROBOTIC EXOSKELETON FOR UPPER-LIMB REHABILITATION

Proper functioning of the shoulder, elbow, and wrist movements play a vital role in the performance of essential daily activities. To assist physically disabled people with impaired upper-limb function, we have been developing an exoskeleton robot (ExoRob) to rehabilitate and to ease upper limb motion. The proposed ExoRob will be comprised of seven degrees of freedom (DOFs) to enable natural movements of the human upper-limb. This paper focuses on the kinematic and dynamic modeling of the proposed ExoRob that corresponds to human upper-limbs. For this purpose, a nonlinear computed torque control technique was employed. In simulations, trajectory tracking corresponding to typical rehabilitation exercises were carried out to evaluate the performances of the developed model and controller. For the experimental part, only 3DOFs (elbow, wrist flexion/extension, wrist abduction/adduction) were considered. Simulated and experimental results show that the controller was able to maneuver the proposed ExoRob efficiently in order to track the desired trajectories, which in this case consisted in passive arm movements. Such movements are widely used in therapy and were performed efficiently with the developed ExoRob and the controller.

Development and control of a robotic exoskeleton for shoulder, elbow and forearm movement assistance

World health organization reports, annually more than 15 million people worldwide suffer a stroke and cardiovascular disease, among which 85% of stroke patients incur acute arm impairment, and 40% of victims are chronically impaired or permanently disabled. This results a burden on the families, communities and to the country as well. Rehabilitation programs are the main way to promote functional recovery in these individuals. Since the number of such cases is constantly growing and that the duration of treatment is long, an intelligent robot could significantly contribute to the success of these programs. We therefore developed a new 5DoFs robotic exoskeleton named MARSE-5 motion assistive robotic-exoskeleton for superior extremity that supposed to be worn on the lateral side of upper arm to rehabilitate and ease the shoulder, elbow and forearm movements. This paper focused on the design, modeling, development and control of the proposed MARSE-5. To control the exoskeleton, a nonlinear sliding mode control SMC technique was employed. In experiments, trajectory tracking that corresponds to typical passive rehabilitation exercises was carried out. Experimental results reveal that the controller is able to maneuver the MARSE-5 efficiently to track the desired trajectories.

Force-position control of a robotic exoskeleton to provide upper extremity movement assistance

This paper presents an upper extremity (UE) wearable robot, ETS-MARSE and its control strategy to provide movement assistance and active rehabilitation exercises to physically disabled individuals having impaired UE function. The ETS-MARSE was designed to be worn on the lateral side of UE and is able to assist arm movements at the level of shoulder, elbow, forearm and wrist joint movements. Considering the dynamic modelling of the robot system and the UE motion which are non-linear in nature, a non-linear sliding mode control with exponential reaching law was used to manoeuvre the ETS-MARSE and to provide both passive and assisted arm movement therapy. To provide passive arm movement therapy, pre-programmed trajectories corresponding to recommended passive rehabilitation exercises were used to manoeuvre the ETS-MARSE, whereas in case of assisted rehabilitation therapy user interaction wrist force sensor signals were used to steer the ETS-MARSE in assisting the UE movements. Experiments involving healthy human subjects were performed with the developed ETS-MARSE to evaluate the controller’s performance and that of the ETS-MARSE in regards to providing the therapeutic exercises. Experimental results indicate that with the proposed control strategy, ETS-MARSE can effectively deliver rehabilitation exercises.

Tele-operation of a robotic exoskeleton for rehabilitation and passive arm movement assistance

A robotic exoskeleton, the MARSE-4 has been developed to provide passive rehabilitation therapy to the physically disabled individuals with impaired upper-limb function. In this paper we focused on the tele-operation of the MARSE-4 using an upper-limb prototype 7DoFs (lower scaled) master exoskeleton arm (mExoArm.) The MARSE-4 has 4DoFs and is able to assist elbow (flexion/extension), forearm (pronation/supination) and wrist joint movements (radial/ulnar deviation, and flexion/extension). Modified Denavit-Hartenberg conventions were used in the kinematic modeling of the exoskeleton. In control, a nonlinear computed torque control and a linear PID control techniques were employed to maneuver the MARSE-4 to follow the desired trajectory. Experimental results show that the MARSE-4 can efficiently track the desired trajectories as generated by mExoArm and therefore guarantee to tele-operate the MARSE to deliver passive therapy for wrist, elbow, and forearm movements.