Effects of the polarity and waveform of the stimulus pulse train on the electrically-elicited pressure sensation

This study was designed to investigate effects of the polarity and waveform of the electrical stimulus pulse train on the electrically-elicited tactile sensation in terms of the sensory activation threshold. The experiments were conducted on 49 healthy subjects for 1) different polarities (anodic and cathodic), and 2) different waveforms (monophasic and biphasic). The findings included that 1) the tactile sensation became adapted to the constant stimulation, 2) the polarity of the pulse train did not make a significant difference in the activation threshold, 3) the required stimulation intensity for the biphasic waveform was almost twice higher than the monophasic waveform, 4) the activation threshold values showed a poor inter-individual consistency, but a strong intra-individual consistency, and 5) our stimulation protocol could be used for eliciting a pressure sensation.