Article

This study determined the feasibility and performance of center of mass (COM)
acceleration feedback control of a neuroprosthesis utilizing functional
neuromuscular stimulation (FNS) to restore standing balance to a single subject
paralyzed by a motor and sensory complete, thoracic-level spinal cord injury. An
artificial neural network (ANN) was created to map gain-modulated changes in
total body COM acceleration estimated from body-mounted sensors to optimal
changes in stimulation required to maintain standing. Feedback gains were
systematically tuned to minimize the upper-limb (UL) loads applied by the subject
to an instrumented support device during internally generated postural
perturbations produced by volitional reaching and object manipulation. Total body
COM acceleration was accurately estimated (>90% variance explained) from 2
three-dimensional (3-D) accelerometers mounted on the pelvis and torso. Compared
with constant muscle stimulation employed clinically, COM acceleration feedback
control of stimulation improved standing performance by reducing the UL loading
required to resist internal postural disturbances by 27%. This case study
suggests that COM acceleration feedback could potentially be advantageous in a
standing neuroprosthesis since it can be implemented with only a few feedback
parameters and requires minimal instrumentation for comprehensive 3-D control of
dynamic standing function.

Langue : ANGLAIS