Review of Control Methods for Upper Limb Telerehabilitation With Robotic Exoskeletons

Given the escalating unmet demand for physical rehabilitation due to the growing global aging population and the effects of the coronavirus COVID-19 including increased incidents of stroke, hospital bed shortages, and clinics closures, robotic telerehabilitation is an emerging, timely, and crucial technology. Rehabilitating the upper limbs of affected patients is of upmost importance for restoring physical function and lighten the societal burden due to disabilities. So far, the majority of the research in robotic telerehabilitation for upper limbs has been performed with end-effector-type assistive robots; however, the use of robotic exoskeletons has significant and distinctive benefits. Although there are surveys written about control methods for upper limb robotic exoskeletons and other surveys written about bilateral teleoperation control methods, there are no surveys written specifically about telerehabilitation control methods for upper limbs using robotic exoskeletons. As a result, this article reviews the state-of-the-art control strategies including various advanced linear and nonlinear control approaches for upper limb rehabilitation robotic exoskeletons, bilateral teleoperation, and several state-of-the-art telerehabilitation applications with upper limb robotic exoskeletons. The benefits, drawbacks, challenges, and future directions of existing methodologies are extensively discussed. This article offers a comprehensive overview and insight for new researchers in the area of telerehabilitation robotic exoskeletons.