CAPTURING SHOULDER MOTION AS AN INPUT FOR EXTERNALLY-POWERED, SHOULDER DISARTICULATION PROSTHESES

Abstract

Prosthetists have been fitting externally-powered components to individuals with “shoulder disarticulation”, upper extremity amputations for decades. These components have ranged from momentary contact switches that permitted carbon-dioxide to pass through tubes in order to create an articulating motion, to force sensitive resistors (FSRs) that vary the amount of resistance between thin conductive plates in order to permit varied current to flow and provide input to an electrical motor. Activation of these types of inputs requires contact by the user with their remaining residual limb or, in the case of individuals with congenital deficiencies, phocomelic digits. A variety of pull switches have also been used to harness the body motions provided by the user, which activate an electro-mechanical switch used to drive a motor. With the use of coupled rotary potentiometers, the authors have chosen to investigate a unique approach to ipsilateral shoulder motion as a control source for two degrees of freedom.