Assist-as-Needed Controller to a Task-based Knee Rehabilitation Exoskeleton

This research aims to design and implement an assist-as-needed controller and patient recovery tracking system into a novel task based knee rehabilitation exoskeleton device. The level of support from the exoskeleton is measured through the force sensing resistors (FSR) placed in the interface of lower- leg and the exoskeleton. The signal from the FSR is used as a feedback to control the actuator torque. The intent of the user to start, stop, move left, and right are associated with muscle activities, surface electromyography (sEMG) signals in the upper-leg. The preliminary results have shown that the system has provided the user a visual display of the amount of recovery and history while providing full autonomy to control the exoskeleton device. The successful implementation of these features can eliminate the need of constant supervision, and hence saves time and reduces cost of the rehabilitation process; which can also be used in a home-based or telerehabilitation settings.