Title: A robot prosthetic finger system based on finger joint angle estimation using EMG signals

Authors: Nozomu Araki; Shintaro Nakatani; Kenji Inaya; Yasuo Konishi; Kunihiko Mabuchi

Addresses: Division of Mechanical Systems, Department of Mechanical Engineering, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo, 671-2201, Japan ' Division of Mechanical Systems, Department of Mechanical Engineering, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo, 671-2201, Japan ' Division of Mechanical Systems, Department of Mechanical Engineering, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo, 671-2201, Japan ' Division of Mechanical Systems, Department of Mechanical Engineering, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo, 671-2201, Japan ' Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan

Abstract: The goal of this study was to develop a robot prosthetic hand system for an amputee that estimates his desired finger angle from neural signals, and operates with the motion he intends. Consequently, we considered a method for estimating finger joint angle from biosignals. We have previously proposed a finger joint angle estimation method based on surface electromyography (EMG) signals and a linear model. This method was based on a histogram of EMG signals, and may be applicable to surface EMG signals as well as neural signals. To confirm this, we carried out finger joint angle estimation experiments using both surface EMG signals and needle EMG signals measured at deep layers of muscles and are similar to neural signals. Moreover, an artificial finger robot has been designed and developed for finger amputation patients. This finger robot has 2-DOF and each joint is worked with motors and cables. The joint angles are controlled by a PID method. Using this robot and applying our proposed finger joint angle estimation method, we carried out experiments in which the robot is synchronised with the subject's third finger motion. As a result, it was confirmed that our system is technically feasible for application to a real prosthetic hand system.

Keywords: electromyograms; surface EMG signals; needle EMG signals; robot fingers; finger joint angle estimation; robot hands; prosthetic hands; prosthetic fingers; finger amputees; biosignals; neural signals; robot motion; robot control; bioengineering.

DOI: 10.1504/IJAMECHS.2013.060015

International Journal of Advanced Mechatronic Systems, 2013 Vol.5 No.6, pp.383 - 390

Published online: 19 Mar 2014 *

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