eLEGS
A THKAF exoskeleton, eLEGS, is developed to support patients
who have difficulties in lower-limb functions of sitting, walking,and standing [8]. Its hip and knee f/e are actuated, while ankle
d/p is passively actuated with a spring. A finite state machine is
used to determine the movements of the two exoskeleton legs.
During walking, one stride cycle is separated into four states: left
swing, left double stance, right swing, and right double stance.
Stance to swing transition is mainly triggered by the user moving
his/her crutches and shifting his/her body weight; swing to stance
transition is mainly triggered by heel strike detection. In sitting
down and standing up maneuvers, the two robotic legs are
actuated symmetrically with the same trajectory: even though,
each leg is controlled separately.
Five subjects with varying SCI levels and completeness tested
eLEGS and all of them were able to quickly learn to use the machine
to deploy consistent cadences [8].