On the development of a walking rehabilitation device with a large workspace.

Rehabilitation therapy aiming at helping a person to regain or improve the ability to walk is a labour-intensive activity. In this context, the patient is often limited to very restricted walking spaces. This paper presents a device that can support the weight of a person walking freely over a large workspace. The device is based on an overhead gantry mechanism combined with a cable routing that decouples the vertical motion from the horizontal displacements of the person. The mechanical architecture is first presented and it is shown that the principle can be applied to the design of a completely passive device in which the portion of the weight to be supported can be adjusted. A simplified dynamic model is also derived in order to highlight the characteristics of the device. A powered version of the device is then discussed. Finally, a prototype of a passive device built at full scale is presented and discussed. A video accompanying the paper illustrates the experimental tests underway with the prototype.