Tactile Vision Substitution Systems
Since the pioneering work performed by Bach-y-Rita et al. [Nature 221 (1969)] several different technologies have been explored to construct devices which are able to provide blind subjects with a substitution for vision making use of their tactile perception. Such devices are called tactile vision substitution systems (TVSS). In general three classes of stimuli, mechanotactile, electrotactile and thermotactile, have been exploited. A comprehensive overview including also applications of tactile displays for sighted people in the context of virtual reality can be found in the nice book by G.C. Burdea : Force and touch feedback for virtual reality, John Wiley & Sons, Inc., New York (1996).
Modern microelectronics offers the fascinating opportunity to develop intelligent vision chips tactile sensory perception. This pneumatic display (PTD) is operated with air pressure and can thus be used in the strong field of an fMRI magnet.