Design of FES based muscle stimulator device using EMG and insole force resistive sensors for foot drop patients

Department of Information Engineering, University of Brescia, Via Branze 38, Brescia, 25123, Italy

Adv. Mater. Lett., 2018, 9 (11), pp 776-780

DOI: 10.5185/amlett.2018.2170

Publication Date (Web): Jul 24, 2018

Copyright © IAAM-VBRI Press

E-mail: m.khan004@unibs.it

Abstract

In the presented research, design of functional electrical stimulation (FES) based muscle stimulator device has been described which is used to correct and enhance the gait activity of foot drop patients. The device mainly comprises of FES unit for electrical pulse generation, an electromyography (EMG) sensor V3 for feedback system and insole force-sensitive resistive sensors (FSR) to control ON/OFF timing of device. The device controls the ankle flexion without excessive eversion or inversion of foot (i.e. balanced flexion) by stimulation of common peroneal nerve and tibialis anterior muscle (TA). The efficiency of device is assessed by evaluating gait temporal and spatial parameters (TSP’s) and 3-dimensional gait kinematics (ankle flexion) of footdrop patients by “Peak Motus Motion Measurement System”. It has been found that use of FES stimulator increases the walking speed by 19%, cadence by 7%, step length by 11% and stride length by 15.5%. In addition, it is also observed that stride time, stance time, step time, single support time and double support time is decreased by 5%, 17%, 22%, 15% and 18% respectively. Moreover, kinematics analysis of foot shows that the device prevented the footdrop up to 30° by controlling the ankle flexion and extension magnitude. Thus, the obtained results suggest that the proposed FES based stimulator device provides enough stimulation to peroneal nerve required for stable gait activity of footdrop patients.

Keywords

Foot drop, functional electrical stimulation (FES), muscle stimulator device, force-sensitive resistive sensors (FSR), gait temporal and spatial parameters (TSP&rsquo,s), 3-dimensional gait kinematics, tibialis anterior muscle, peroneal nerve.