Preliminary assessment of variable geometry stair ascent and descent with a powered lower limb orthosis for individuals with paraplegia

This paper describes a controller for a lower-limb exoskeleton that enables variable-geometry stair ascent and descent for persons with lower limb paralysis. The controller was evaluated on a subject with T10 complete spinal cord injury (SCI) on two staircases, one with a riser height and tread depth of 18.4 × 27.9 cm (7.25 × 11 in) and the other 17.8 × 29.8 cm (7 × 11.75 in). The controller enabled ascent and descent of both staircases without explicit tuning for each, and with an average step rate of 12.9 step/min during ascent and 14.6 step/min during descent.