Design of a novel robotic over-ground walking device for gait rehabilitation

It is a well known fact that robotic-assisted gait rehabilitation can not only reduce labor intensity for therapists, but also potentially lead better functional outcomes than conventional therapy. Though current treadmill based devices are rather limited in their pelvic motions and can allow only one forward plane of motion. In this study, we present a novel robotic walking platform with an omni-directional mobile platform, an intuitive human-machine interface, an active body weight support (BWS) unit, and wearable motion capture system. The omni-directional platform coupled with BWS system allows unrestricted natural pelvic and trunk motion while walking. One can interacts with the system via an admittance control system based on a six degree-of-freedoms (DoFs) force/torque (FT) sensor. The admittance controller with virtual mass and damper parameters enables a natural and intuitive interface. In this study, we compared the velocities of the center of mass (CoM) of forward-backward, lateral and rotational movements with and without the device. Confirming the feasibility of the device, the result has shown that the forward-backward velocity was reduced by wearing the device while the other velocity profiles with and without the device showed no meaningful changes. Unlike treadmill based devices, the developed device turned out to support any locomotion in any direction while walking. This device can have potential to improve the mobility of the neurologically challenged by providing natural gait patterns, and these findings call attention to the possible further studies on extensive human sensorimotor learning system.