Form perception with a 49-point electrotactile stimulus array on the tongue: A technical note

Form perception with the tongue was studied with a 49-point electrotactile array. Five sighted adult human subjects (3M/2F) each received 4 blocks of 12 tactile patterns, approximations of circles, squares, and vertex-up equi lateral triangles, sized to 4x4, 5x5, 6x6, and 7x7 electrode arrays. Percep tion with electrical stimulation of the tongue is better than with fingerti p electrotactile stimulation, and the tongue requires 3% (5-15 V) of the vo ltage. The mean current for tongue subjects was 1.612 mA. Tongue shape reco gnition performance across all sizes was 79.8%. The approximate dimensions of the electrotactile array and the dimensions of compartments built into d ental retainers have been determined. The goal is to develop a practical, c osmetically acceptable, wireless system for blind persons, with a miniature TV camera, microelectronics, and FM transmitter built into a pair of glass es, and the electrotactile array in a dental orthodontic retainer.