An investigation into the reliability of upper-limb robotic exoskeleton measurements for clinical evaluation in neurorehabilitation

Robotic exoskeletons are increasingly being used for neurorehabilitation, due to a number of perceived advantages. Once such advantage is the potential to use the large amounts of previously unavailable measurements to provide continuous assessment of the patient. This study investigates the validity of such measurements through an experimental protocol. Reaching movements within and outside an upper-arm rehabilitation exoskeleton (ArmeoPower) of 10 healthy subjects are compared using five commonly-used kinematic metrics (Peak Speed, Time to Peak Speed, Curvature, Smoothness, Accuracy). The study finds that (1) the robotic exoskeleton significantly affects the reaching movements of healthy subjects, (2) the measurements of the exoskeleton accurately represent the movements of the wrist, and (3) evolution of the in-exoskeleton movements over multiple sessions is indicative of changes in movements outside the robot, even though differences remain - suggesting that evolution of this data may be used to monitor patient progress.