ReGear: an upper and lower limb simultaneous system for stroke rehabilitation

Rehabilitation robotics is a rapidly advancing field that improves the treatment methods for several neurological injuries, including motor recovery for post-stroke patients. However, most of the structures consider upper and lower limb exercises separated. This paper concerns the development of a novel robotics structure called "ReGear" designed for a combined process of providing rehabilitation and helping post-stroke patients perform simple training sessions of both paretic limbs, simultaneously. The main goals of this structure are to assist motor recovery and improve the coordination of both affected limbs. Initially, a mathematical model of the proposed device is developed based on the geometrical relations and desired angular motion. Therefore, a tridimensional model is constructed and applied to computational simulations. Afterward, a prototype is built, including a microcontroller and a DC motor coupled with a rotary encoder. An assist-as-needed control design is applied to the system, which is connected to an electronic game developed to enhance the experience during the training sessions. The clinical trial tests were performed on healthy and post-stroke subjects, applying surface electromyography to correlate the muscular activity of both limbs with the system and game response. The experimental results demonstrate good responsiveness of ReGear and preliminary evidence that it can provide active-passive motion training for patients recovering from a stroke.