Automatic identification of gait events using an instrumented sock

And maybe we could put estim in there also to prevent
inversion.
http://www.jneuroengrehab.com/content/8/1/32/
Abstract (provisional)
Background
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