Stair ascent assistance for cerebral palsy with robot suit HAL

Cerebral palsy (CP) patients require a wheelchair for moving when their lower limbs are severely paralyzed. Wheelchair users have issues moving around due to the lack of optimal infrastructure. We achieved a voluntary walking of a CP patient who uses wheelchair by using our developed hybrid assistive limb (HAL). In addition to voluntary walking, if HAL realizes voluntary stair climbing, it is expected that patients will acquire a wider range of activities than using a wheelchair. This study focuses on stair ascent. The purpose of this study is to propose an automatic control method for stair ascent assistance, and to verify the effectiveness of the proposed method. In this method, a phase of stair ascent is determined by proposed phase determination based on a height of landing area, CoGRF in sagittal plane and lateral plane. Proposed automatic control generates torque for assisting each phase movement during stair ascent. As an experiment, healthy male subject went through a course including flat area and stairs. As a result, we verified that the phase determination could determine the phase during stair ascent and switch between the walking assistance method and stair ascent assistance method. The proposed automatic control generated torque for assisting movement of each phase. We found this proposed method is applicable to for walking and stair ascent assistance.