Upper-Limb Robotic Rehabilitation Exoskeleton: Tremor Suppression

Abstract

Tremor is the most common movement disorder and is an important source of functional disability, affecting many daily tasks. For cases where treatment is not successful, the path to take is technological aids in the form of mechanisms attached to the arm (robotic exoskeletons). This article has evaluated the different aspects of the WOTAS robotic exoskeleton. The WOTAS was evaluated with patients in real situations and a number of clinical tasks were defined, which were selected when the evaluation was done with the systems. Ten patients took part in the clinical experimentation stage of the system. The patients wore the device while it operated in three possible operation modes: monitoring, passive suppression and active suppression. Clinical effectiveness (from the variables obtained) and user acceptance were the base for selecting the best combination of algorithm parameters. Flaccidity and white tissue characteristics of the muscular system were the main disadvantages to providing the compensatory force on the arm, at the moment when the algorithms intervened to suppress tremor. However, reductions of approximately 80% in tremor power were obtained in patients suffering severe tremor. From the results and tremor reduction obtained in the system evaluation trials, the importance of these exoskeleton devices was demonstrated.