Control Methods for Improving Mobility for Persons with Lower Limb Paralysis

Abstract

Described herein are rehabilitative intervention methods that: 1) enable paraplegics to ascend and descend stairs with a lower limb exoskeleton; 2) enhance exoskeleton assisted walking with supplemental FES to overcome moderate to severe spasticity; and 3) suppress clonus using FES during seated mobility. The stair controller combines predefined trajectory tracking with an emulated passive state that enables gravity to extend the leg until it meets the next stair tread so that individuals can traverse stairs independent of step height. Regarding the second intervention, subjects with moderate to severe spasticity are typically ineligible for exoskeleton assisted gait due to pathological muscle activation that opposes exoskeleton mediated motion. The supplemental stimulation controller was implemented with a lower limb exoskeleton and integrated stimulator to expand the inclusion criteria of exoskeletons whereby FES enhances the synergy between muscles and motors and allowed paraplegic individuals with moderate to severe spasticity to achieve normal gait kinematics. Lastly, the clonus intervention has provided a robust noninvasive treatment for clonus, that may provide an economical alternative to invasive and commonplace pharmacological interventions.