[Artificial vision for the human blind]

Since 1960 many attempts have been made to develop visual prostheses for the blind; most of the devices based on the production of phosphenes through electrical stimulation with microelectrodes at the retina, optic nerve, lateral geniculate or occipital lobe are incapable to reconstruct a coherent retinotopic map (coordinate match between the image and the visual perception of the patient); furthermore they display important restrictions at the biomaterial level that hinder their final implantation through surgical techniques which at present time offers more risks than benefits to the patient. Considering the new theories about intermodal perception it is possible the acquisition of visual information through other senses; The Micromechanics and Mecatronics Group (GMM) from The Center of Applied Sciences and Technological Development at The National Autonomous University of Mexico by this paper, describes the experimental design and psychophysical data necessary for the construction of a visual sensory substitution prostheses with a vibrotactile system. The vibrotactile mechanism locates different bars over the epidermis in a predetermined way to reproduce a point by point matrix order in a logical sequence of rows and columns that allow the construction of an image with an external device that not require invasive procedures.