Automatic identification of gait events using an instrumented sock

Abstract

BackgroundTextile-based transducers are an emerging technology in which piezo-resistive properties of materials are used to measure an applied strain. By incorporating these sensors into a sock, this technology offers the potential to detect critical events during the stance phase of the gait cycle. This could prove useful in several applications, such as functional electrical stimulation (FES) systems to assist gait.MethodsWe investigated the output of a knitted resistive strain sensor during walking and sought to determine the degree of similarity between the sensor output and the ankle angle in the sagittal plane. In addition, we investigated whether it would be possible to predict three key gait events, heel strike, heel lift and toe off, with a relatively straight-forward algorithm. This worked by predicting gait events to occur at fixed time offsets from specific peaks in the sensor signal.ResultsOur results showed that, for all subjects, the sensor output exhibited the same general characteristics as the ankle joint angle. However, there were large between-subjects differences in the degree of similarity between the two curves. Despite this variability, it was possible to accurately predict gait events using a simple algorithm. This algorithm displayed high levels of trial-to-trial repeatability.ConclusionsThis study demonstrates the potential of using textile-based transducers in future devices that provide active gait assistance.

E-textiles in Clinical Rehabilitation: A Scoping Review

“…Unfortunately, although the authors described a dynamic walking test, no quantitative results were reported. On a related front, Preece et al [38] created an instrumented sock to identify heel strike, heel lift, and toe off during the gait cycle. The sock contained knitted strain sensors formed using the characteristics of the knitting pattern, which allowed loops of conductive yarn to come into or out of contact with each other as the fabric stretched, decreasing or increasing the effective length of the conductor and proportionally, the resistance.…”

Gait Segmentation Method Using a Plantar Pressure Measurement System with Custom-Made Capacitive Sensors

“…Some research papers describe textile implementations for actigraphy and gait analysis. These works show the development and implementation of smart socks with embedded pressure and strain sensors [6][7][8][9][10][11][12], and they have shown results in movement classification. However, embedding electronics in a sock usually take place outside the textile structure, which makes it uncomfortable to the user and could affect normal gait conditions.…”

Beyond Cognitive and Affective Issues: Designing Smart Learning Environments for Psychomotor Personalized Learning

“…Aimed to reduce the intrusion while gathering data, e-textiles can track different kinds of phenomena (Fleury, Sugar, & Chau, 2015), such as strain (Gioberto & Dunne, 2013;Giorgino, Tormene, Lorussi, de Rossi, & Quaglini, 2009;Preece et al, 2011;Tormene et al, 2012;Yamada et al, 2011), acceleration (Harms, Amft, & Troester, 2010;Zysset et al, 2013), joint movements (Lee, Lee, Kim, & Lee, 2011), bend angle (Lorussi, Galatolo, & Bartalesi, 2013), posture (Di Rienzo et al, 2009), or pressure (Shu et al, 2010).…”