Sensation thresholds for vibrotactile information transfer

The authors present results of determining sensation thresholds to vibration waveforms in a range of frequencies and duty cycles for vibrotactile information transfer applied to the visually handicapped. The stimulation waveform is composed of an excitatory part, i.e. a burst of rectangular pulses, and a recovery time, i.e. a period of no stimulation, to minimize adaptation. Several subjects were tested, all giving similar threshold curves. The results make it possible to determine a combination of parameters that permits optimization of sensation with minimization of power delivered