This study aimed at developing a prototype of portable FES rehabilitation system for relearning gait pattern of healthy subjects, which can measure gait information during walking applying electrical stimulation for foot drop correction or providing timing information. A gait event detection method using an inertial sensor attached on the foot was determined based on gait of healthy subjects from simultaneous measurements with pressure sensors. From the result of comparing the detected gait event timings with EMG signal of the tibialis anterior muscle during walking of healthy subjects, the toe off and the foot flat timings detected by the inertial sensor were suggested to be useful to determine the stimulation timing for the foot drop correction. The gait event detection method was implemented in a prototype of portable FES rehabilitation system consisting of an 8-inch tablet-type device, 2 inertial sensors and an electrical stimulator. The portable system was examined with hemiplegic subjects under the conditions of FES foot drop correction and inducing voluntary effort to develop ankle dorsiflexion at the timing given by electrical stimulation with small stimulation intensity. The system was considered to be useful for gait rehabilitation of hemiplegia using FES foot drop correction or inducing voluntary effort.
Keywords: ankle dorsiflexion; biomedical measurement; electromyogram signal; electromyography; foot drop correction; gait analysis; gait event detection method; gait information measurement; gait relearning; hemiplegia; inertial sensor; medical disorders; patient rehabilitation; portable FES rehabilitation system; portable functional electrical stimulation rehabilitation system; pressure sensor; pressure sensors; tibialis anterior muscle; walking.