Manual and automatic control of FES-assisted indoor rowing exercise

An indoor rowing exercise system has been developed for paraplegics in which voluntary upper body movements are combined with electrically stimulated movements of the paralyzed leg muscles for total body exercise. Manual and automatic functional electrical stimulation (FES) control strategies have been used to control the stimulation intensities and coordinate the voluntary and FES generated movements. In manual control, voluntary button presses control the timing of stimulation while in automatic control a two-level hierarchical controller manages the movement coordination and stimulation delivery to the paralyzed muscles. Paraplegic volunteers found both controllers intuitive and easy to use. Automatic control spends more electrical stimulation per rowing cycle but it is more convenient and natural to use, continuous concentration on the movement and repeated thumb presses are not necessary, and it extends the user base of the FES rowing to paraplegics with higher level injury who can not press on the buttons but can pull/push the handlebar.