Investigation of user load and evaluation of power assistive control on cycling wheelchair

Wheelchairs, walkers, and electric wheelchairs are well-known support devices for patients with lowerlimb disabilities. However, disuse of lower limbs presents an ongoing barrier to rehabilitation, and can eventually lead to disuse syndrome. To overcome this situation, researchers have designed the cycling wheelchair. The cycling wheelchair is accessible to most patients who can bend their lower limbs. It is primarily used in rehabilitation facilities with planar floors and gentle slopes. To become practicable for everyday use, cycling wheelchairs require sufficient power to travel up steeper slopes or across bumpy surfaces. This paper aims to clarify the power consumed by users in everyday environments by measuring the tread force on the pedals. The investigation targets lower-limb disabled subjects and unimpaired subjects. It was observed that some of the users could not summon sufficient power for uphill travel. In addition, hemiplegic subjects with only one unimpaired leg placed large load on their healthy limb. As a first step to overcome this problem, we introduce traveling resistance compensation control into a cycling wheelchair and evaluate its efficacy.