An electrical stimulator for sensory substitution

This work presents an electrical stimulator system for use in sensory substitution (SS), as a mobility aid for visually handicapped people. The whole system passes visual information via cutaneous stimulation, and consists of a webcam, a PC, dedicated hardware to generate stimuli and a 15 x 20 electrode matrix. The same system can also be used in psycophysical and somesthesic research, or even for SS of deaf people, by changing the input signal from a camera to a microphone, and adapting its control software. Circuits for pixel addressing, for signal generation and for switching are described, as well as the software involved in generating a pulse train, which configures the stimuli patterns.