Article

This study explores the feasibility of a hybrid system of exoskeletal bracing and
multichannel functional electrical stimulation (FES) to facilitate standing,
walking, and stair climbing after spinal cord injury (SCI). The orthotic
components consist of electromechanical joints that lock and unlock automatically
to provide upright stability and free movement powered by FES. Preliminary
results from a prototype device on nondisabled and SCI volunteers are presented.
A novel variable coupling hip-reciprocating mechanism either acts as a standard
reciprocating gait orthosis or allows each hip to independently lock or rotate
freely. Rotary actuators at each hip are configured in a closed hydraulic circuit
and regulated by a finite state postural controller based on real-time sensor
information. The knee mechanism locks during stance to prevent collapse and
unlocks during swing, while the ankle is constrained to move in the sagittal
plane under FES-only control. The trunk is fixed in a rigid corset, and new ankle
and trunk mechanisms are under development. Because the exoskeletal control
mechanisms were built from off-the-shelf components, weight and cosmesis
specifications for clinical use have not been met, although the power
requirements are low enough to provide more than 4 hours of continuous operation
with standard camcorder batteries.

Langue : ANGLAIS