Controlled energy flow in hybrid orthosis for generating functional swing phase of biped walking

During this study we have introduced a new concept in othosis action "controlled energy flow". Based on this concept, a spring is used for knee flexion and the gravity force is used to assist hip flexion and also artificila stimulating muscle are used as a power source. In this study it is proposed that active contraction of muscles might be articially replaced by a spring knee orthosis to provide near-natural swing phase trajectory than that produced by the flexion reflex for gait in sprinal cord inhured subjects. The spring brake orthosis (SBO) is a new gait restoration system in which stored spring elastic energy and potential energy of limb segments are motion. A hybrid SBO approach is proposed in which a mechanical orthosis with on-off brakes at the hip and knee and a spring to oppose knee extension is combined with electical stimulation of the knee extensors. A low duty cycle of quadriceps stimulation in assemed to lead to minimal muscle fatigue. It is also shown that hip flexion can be produced without the need for withdrawal reflex, hip flexor stimulus or any mechanical actuator at the hip. Simultaneous hip and knee flexion leads to improved ground clearance sompared to conventional reciprocationg gait orthoses. A hip flexion angle of 21 degrees was achieved by a non-impaired subject wearing a prototype prthosis.

کلیدواژه ها:

Locomotion ، Man-machine interfaces ، leg ، Gait ، Orthosis