rehabilitation robotics

ARGO structure is based on a commercial passive Reciprocated Gait Orthosis (RGO) for Cerebral Palsy (CP) children, which has been modified to accomodate sensors and actuators. ARGO is intended for patients who can still apply a certain amount of force with their legs, at least enough to slightly raise up a feet. Thus, we want to motivate the patient to use his muscles by amplifying or facilitating the movements, rather than binding the trajectory to a walking pattern. In fact, although it is possible to find some common patterns on CP patient’s walk (crouch gait, scissor walking or toe walking), the actual walk varies a lot from patient to patient. Each walking strategy comes from the adaptation of the patient to his own body’s pathology, which are highly specific. Thus, forcing the user to adopt a normal walk would be not only useless, but possibly even dangerous for the patient. This drove us to the exigence of developing a non-coercive device, able to detect the force that the wearer is applying with his thigh, and appropriately compensate the joint torque. This is obtained using force control technology. Another innovative aspect is the minimal actuator arrangement which allows to reduce the complexity and cost while exhibiting high system transparency. In fact we arrange pneumatic artificial muscles in non-antagonist configuration exploiting the NFW mechanical reciprocation.