Study on the Design and Analysis of a 4-DOF Robot for Trunk Rehabilitation

Abstract

This paper presents the development of a robotic system for rehabilitation of the trunk’s ability to maintainpostural control under different balance conditions. The system, developed with extensive input from rehabilitationand biomedical engineering experts, consists of a seat mounted on a robotic mechanism capable of moving itwith four degrees of freedom (3 rotational and 1 translational). The seat surface has built in instrumentation togauge the movements of the user’s center of pressure (COP) and it can be moved either to track the movementsof the COP or according to operator given commands. The system allows two types of leg support. A groundmounted footrest allows participation of legs in postural control while a seat connected footrest constrains the legmovement and limits their involvement in postural control. The design evolution over several prototypes ispresented and computer aided structural analysis is used to determine the feasibility of the designed components. The system is pilot tested by a stroke patient and is determined to have potential for use as a trunkrehabilitation tool. Future works involve more detailed studies to evaluate the effects of using this system and todetermine its efficacy as a rehabilitation tool.