A haptic device-based reproduction system of active finger movement and its evaluation using sensory evoked potentials

To develop an experimental system that could be used for physiological experiments on voluntary finger movements in humans, we developed an experimental system that can realize passive finger movements by reproducing recorded users' own active movement trajectories using a haptic device called SPIDAR-GCC. The efficacy of the system was verified through high agreement of the finger trajectories between active and passive movements and no muscle activations during the passive movements. We further confirmed that high signal-to-noise ratio sensory evoked potentials (SEPs) derived from median nerve stimulation of the wrist was observed by electrical stimulation exceeding motor threshold without muscle fatigue throughout the experiment. As N20/P25 component of SEPs from 20 participants showed amplitude changes according to the movement conditions, these results suggested that the proposed experimental system has the capability to be utilized as a physiological experimental system for elucidating the neural control mechanisms of voluntary movements.