Modeling, implementation and control of a forearm-wrist rehabilitation devi

Official URL: http://risc01.sabanciuniv.edu/record=b1427173 (Table of Contents)

Using robotic devices in repetitive and physically involved rehabilitation exercises helps eliminate the physical burden of movement therapy for the therapists, and enables safe and versatile training with increased intensity. Robotic devices allow quantitative measurements of patient progress while enforcing, measuring, and evaluating patient movements. Furthermore, with the addition of virtual environments and haptic feedback, rehabilitation robots can be used to realize new treatment protocols. This thesis presents the design, implementation, and control of a parallel mechanism based exoskeleton that can be used to impose targeted therapeutic exercises to forearm and wrist. After the kinematic and dynamic model of the exoskeleton is formalized, the workspace and the dimensions of the device have been optimized considering multiple objective functions. Once the device has been implemented, experiments have been conducted in real-time to characterize its performance. The exoskeleton is subsequently controlled using a novel method to have been used in rehabilitation domain, the passive velocity field control. This control method minimizes the “contour error” rather than the trajectory error while keeping the system passive with respect to external torque inputs. Then, the forearm-wrist exoskeleton has been adapted as a part of a rehabilitation system that implements the multi-lateral shared control concept for rehabilitation. The multi-lateral rehabilitation system allows for patients to train with on-line virtual dynamic tasks, in collaboration with a therapist. Different control authority can be assigned to each agent such that therapists can guide or evaluate movements of patients, or share the control with them.