Robotic index finger prosthesis using stackable double 4-BAR mechanisms

Abstract

This paper suggests a robotic index finger prosthesis realized to be one degree-of-freedom by using stackable double 4-bar mechanisms. Also its control method makes use of two electromyographic (EMG) signals measured on skin surfaces of flexor digitorum superficialis (FDS) and extensor indicis (EI) in a lower arm. In this paper, we assume that EMG signals have some relations with velocity of muscle movement by neglecting finger dynamics due to its negligible small mass. In order to obtain desired position and velocity of robotic index finger, the measured raw EMG signals are processed by sequential procedures such as root mean squaring, applying threshold operation to extract the initial burst part, subtracting antagonistic EMG signal, and integrating by every 2millisecond. Finally the effectiveness of the suggested mechanism and control method is verified through experiments.