Article

Textile-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. METHODS: We 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. RESULTS: Our 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. CONCLUSIONS: This study demonstrates the potential of using
textile-based transducers in future devices that provide active gait assistance.

Langue : ANGLAIS