Design and Simulation of a Simplified Mechanism for Sit-to-Stand Assisting Devices

Ottaviano E.;Rea P.;Errea P.;Pinto C.

2013-01-01

---

Abstract

Standing up deals with the transition from two stable postures, namely the seated and standing ones, with a movement concerning all body segments except the feet. The transfer from sitting to standing and back requires both voluntary movement of different body segments that contribute to the change of posture and equilibrium control during an important displacement of the Centre Of Gravity (COG) of the body. This operation can be considered of great importance for impaired and elderly people to achieve minimal mobility and independence in daily life activities. In this paper we propose the design of a simplified mechanism to be used in assisting device for aiding the sit-to-stand. In particular, experimental tests are carried out to track and record point trajectories and the orientation of the trunk during the sit-to-stand. Twenty healthy adult volunteers were recruited for a trial in order to derive a suitable theoretical trajectory of the point of interest. Finally, according to the experimental results, a proposal and simulation are presented for a novel mechanical system. In particular, in this paper a suitable theoretical trajectory of the point of interest is used to derive a 1-DOF mechanism, which is able to reproduce the requested motion.