Evaluation of sensation evoked by electrocutaneous stimulation on forearm in nondisabled subjects

Few studies are available in the literature on the sensations artificially created by dual-channel electrocutaneous stimulation. This study assessed the effect of a set of selected stimulation parameters on the sensations evoked by single- or dual-channel electrocutaneous stimulation. The investigated parameters included the stimulation site, the number of pulses, the number of stimulating channels (single- vs dual-channel), and the interleaved time between two channels. The modality, quality, location, and magnitude of the sensations were evaluated when the stimulations were applied on the forearm skin in 16 nondisabled subjects. Tactile perception was found to be induced more easily on the median and ulnar aspect than the dorsal and radial aspect of the forearm. Stimulation site significantly affected the magnitude of the sensation (p < 0.01). Dual-channel stimulation significantly increased the sensation magnitude (p < 0.05) only when the two electrodes were positioned closely. Moreover, a higher number of pulses evoked a movement perception more frequently and the interleaved time showed no significant effect on the magnitude of the sensation. The findings are expected to be useful for sensory substitution and augmentation applications. The results may also help improve users' acceptance of hand prostheses.