Therapist-in-the-Loop Robotics-Assisted Mirror Rehabilitation Therapy An Assist-as-Needed Framework

This paper presents a Therapist-in-the-Loop (TIL) framework for robotics-assisted mirror rehabilitation therapy integrated with adaptive Assist-as-Needed (ANN) training, to be adjusted based on the impairment and disability level of the patient’s affected limb. The framework provides a Patient’s Functional Limb (PFL)-mediated therapy, in the sense that therapeutic training is transferred from the therapist to the Patient’s Impaired Limb (PIL) through the PFL medium. This allows the patient to use his/her PFL to adjust the desired trajectory generated by the therapist, if the trajectory is felt to be painful or uncomfortable for the PIL. Closed-loop system stability has been investigated in the presence of communication delays. For this purpose, a combination of the Circle Criterion and the Small-Gain Theorem has been applied to account both for time-delay and the time-varying adaptive ANN training. Experiments to investigate the performance of the proposed framework are reported.