Development and evaluation of simplified EMG prosthetic hands

Abstract

Millions of physical disabilities, who have lost a hand or both hands, are in need of prosthetic hands not only for decoration but also for the functions to help them with basic daily activities. Although EMG prosthetic hands are being extensively studied to satisfy this need, most of them are too expensive to be economically available, difficult to operate and maintain by a user him/herself, or over heavy for longtime wearing. The aim of this study is therefore to develop a simplified EMG prosthetic hand (sim-EMGPH) to solve these problems. The sim-EMGPH consists of five parts: a lightweight robotic hand with two motors to realize the most frequent hand activities, a highly stretchable cosmetic glove with little load on the motors, an EMG measurement system including sensors with high wearability made of soft conductive materials, a controller implemented by a 32-bit microprocessor which performs EMG signal processing, pattern recognition, and motor control, and a human-friendly tablet interface for the user to operate the sim-EMGPH by him/herself. We manufactured three sim-EMGPHs for three subjects: two with congenital upper limb deficiency and one with upper limb amputation. Free task experiments showed that the subjects could operate the sim-EMGPHs by themselves to perform basic activities of daily living. Limitations revealed and improvement plans are also discussed in this paper.

sEMG Sensor Using Polypyrrole-Coated Nonwoven Fabric Sheet for Practical Control of Prosthetic Hand

“…This process decreases the accessibility of myoelectric prosthetic hands, especially for those who are poor and living in undeveloped areas. The goals of our current study and our preliminary studies (Jiang et al, 2014a , 2015 ) are to develop a low-cost and highly usable myoelectric prosthetic hand system in order to increase its accessibility, both economically and technically. In order to provide the technology and the opportunities necessary for people with disabilities to maximize their quality of life by using prosthetic hands, the whole system including the sEMG measurement should be conveniently adaptable to any person, since each person represents different conditions.…”

“…The subjects wearing the sensor band tried to control a prosthetic hand developed in a preliminary study (Jiang et al, 2014a ). The prosthetic hand consisted of a lightweight robotic hand with two motors to realize power grasp, precision grasp, and lateral grasp, a socket to mount the hand to the residual forearm, and a controller (SH72544R, Renesas Electronics Corporation, Japan) that performed EMG signal processing, pattern recognition, and motor control.…”

“…The 3-channel sEMG sensor band with the same structure as shown in Figure 3 was worn below the elbow, and the wet Ag/AgCl electrodes for comparison were adjusted to the same positions (Figure 6 ). The basic architecture of the pattern recognition algorithm was developed in the preceding study (Jiang et al, 2014a ). The data were sampled at 1600 kHz.…”

“…The objective of this study is therefore to develop usable and customizable sEMG sensors for practical control of a prosthetic hand in daily life. In preliminary studies, we developed both multi-DoF prosthetic hands with an interactive-wire driven mechanism (Seki et al, 2013 ; Morishita et al, 2014 ) and two DoF prosthetic hands simplified for quick practical use (Jiang et al, 2014a ). An fMRI study with amputees showed the adaptation process in the brain for control of the prosthetic hand (Kato et al, 2009 ).…”

A Mobile Exoskeleton Control System Using Electromyographic Signals from Human Muscles

“…To estimate more detailed characteristics reflecting complicated contraction patterns, spectral characteristics of EMG signal, isolation of potentials of motor unit action [6] using classification [7] and different methods of machine learning [8][9][10] are used.…”