Development of electrical stimulation method for moving a stimulus point using interferential current.

In the present study, we examined the dynamic range at each medium frequency (1 to 10 kHz) to explore the optimal frequency of the electrocutaneous stimulation using the interferential current method for sensory substitution system. Although the sensory, motor, and pain thresholds increased monotonically with respect to the frequency, the difference between sensory and motor thresholds was max at 5 kHz. Then, we examined the influence of the difference in phase and volume between two alternating currents at 5 kHz on the subjective sensing of the stimulus. When the subject increased the phase difference between two alternating currents, the subject felt that the sensing point moved clearly as one point. Our result implies that this stimulation method can transfer the spatial information with few electrodes. [ABSTRACT FROM AUTHOR]