Electrical and Mechanical Technologies in Sensory System Feedback and Control: Cybernetics in Physical Rehabilitation

Abstract

Studies involving sensory substitution or feedback date back to the 1960s. These seek to apply stimuli to body regions with full sensitivity to replace the information lost due to damaged, deficient, or absent sensory pathway. The main techniques applied are electrotactile stimulation (ETS) and vibrotactile stimulation. The objective of this article is to present a synopsis of current knowledge regarding technologies that employ electrical, mechanical, and pneumatic resources in the sensory system as tools for physical rehabilitation. ETS can be applied as a therapeutic intervention in the treatment of equilibrium disorders, as systems of myoelectric prostheses in amputees whose mechanoreceptors were removed together with the limb, as artificial skins developed prior to the application of prostheses and as prophylactic treatments for pressure sores. Vibrotactile or mechanotactile sensory substitutions that employ electromechanical and piezoelectric devices or inert gas jets facilitate the training of equilibrium maintenance in patients with vestibular alterations, as well as the development of alternative and expanded communication technologies in signaling and augmented reality for people with auditory and/or visual disabilities. The cybernetic resources developed for physical rehabilitation described herein were shown to efficiently generate sensory stimuli and the artificial control of tactile perception. Notwithstanding the greater functional simplicity of mechanotactile systems, the majority of the reviewed studies focused on ETS systems. The results of this study demonstrate the progress and potential of these technologies, as well as the results of evaluations of their use and current limitations in the electrical and mechanical devices employed in functional sensory system rehabilitation.