Arm rehabilitation with a robotic exoskeleleton in Virtual Reality

Several studies demonstrate the importance of an early, constant and intensive rehabilitation following cerebral accidents. This kind of therapy is an expensive procedure in terms of human resources and time, and the increase of both life expectance of world population and incidence of stroke is making the administration of such therapies more and more important. The development of new robotic devices for rehabilitation can help to reduce this cost and lead to new effective therapeutic procedures. In this paper we present an exoskeleton for the robotic-assisted rehabilitation of the upper limb. This article describes the main issues in the design of an exoskeletal robot with high performance, in terms of backdrivability, low inertia, large workspace isomorphic to the human arm and high payload to weight ratio. The implementation of three different robotic schemes of therapy in virtual reality with this exoskeleton, based on an impedance control architecture, are presented and discussed in detail. Finally the experimental results of a preliminary evaluation of functionality of the system carried out on one patient are presented, and compared with the performance in the execution of the exercise obtained with healthy volunteers. Moreover, other preliminary results from an extended pilot clinical study with the L-Exos are reported and discussed.