Estimation and volitional feedback control of active work rate during robot-assisted gait

Body weight supported robotic-assisted devices are normally used in gait rehabilitation of neurologically impaired persons but also have potential for application in cardiopulmonary rehabilitation. In this paper, a method of estimating and controlling the rate of active work done during supported stepping is proposed and experimentally validated through ambulation of three subjects with a spinal cord injury. The estimation and feedback scheme enabled work rates to be produced in close agreement to reference values. The efficacy of the proposed control scheme will facilitate the use of the technology in cardiopulmonary training and testing protocols.