Functional Electrical Stimulation and robotics devices: two complementary approaches to foster motor re-learning

Hybrid Rehabilitation Systems, combining Functional Electrical Stimulation (FES) with powered robotic devices can intensify the outcomes of neuromotor rehabilitation by taking full advantage of the combination of the two technologies. On one side, FES enhances neural plasticity, thus improving motor relearning, but FES-induced movements are hard to control due to the non-linear and time-dependent nature of the induced muscle contraction and are affected by the early onset of muscle fatigue, which limits a prolonged training. On the other side, robotic devices provide smooth motion, strong forces and endless training, but can be bulky and expensive. Combination with FES could enable motors’ power reduction, thus reducing robot encumbrance, and can promote a more active training. However, the combination of these two technologies poses several challenges in the design, control and clinical uptake of hybrid FES robotic systems. In this talk, I will present the state of the art of hybrid FES robotic systems, focusing on the current challenges in the design of a shared control which compensates for muscle fatigue and adapts to single users’ residual capability, and in the implementation of intuitive and self-calibrated procedures. The current evidence about the efficacy of hybrid systems will be also presented and clinical perspectives will be discussed.