1 Laboratory of Clinical Neurophysiology, 'Salvatore Maugeri' Foundation, IRCCS, Scientific Institute of Milan, Milan, Italy; Department of Informatics, Bioengineering, Robotics, System Engineering (DIBRIS), University of Genoa, Genoa, Italy. Electronic address: pbalbi@fsm.it.
2 Department of Informatics, Bioengineering, Robotics, System Engineering (DIBRIS), University of Genoa, Genoa, Italy.
3 Service of Rehabilitation Engineering, 'Salvatore Maugeri' Foundation, IRCCS, Scientific Institute of Pavia, Pavia, Italy.