Real time gait event detection during FES paraplegic walking

Functional electrical stimulation (FES) can used for standing and stepping in complete spinal cord injury (SCI) patients. A proposed method to enhance the performance of FES gait is through the use of feedback control to modify the muscle stimulation on a cycle-to-cycle or next-step basis. An essential component of such a controller is the knowledge of the timing of the gait cycle and gait events. The innovative feature in this work is the use of a multi-level gait event detector. The gait events are detected from insole force measurements in real time. The lower level of the detector, which is based upon previous classification work, estimates the phase of gait at each time sample. The upper level of the detector uses recently developed supervisory rules to detect the transitions between the phases, i.e. the gait events. The gait events of paraplegic patients walking with FES are detected in real time. The gait events of most interest, heel strike and toe off are detected within ±9% of the gait cycle duration