Distance Feedback Travel Aid Haptic Display Design

This chapter introduces approaches of electronic travel (walking) aid (ETA) interface for visual information deficit and gives discussions on the high integrity design concept under restrictions of visualtactile sensational characteristics in substitution process. Here, we start from the concept formulation of ETA. The concept of ETA human interface is based on the sensory substitution between visual and tactile sensation. If human has lost the visual information caused by some sort of environment interference or physical troubles, this ETA assist the subjects to obstacle avoidance self-walking with transferring some environment information (depth, image, object and so on). Since the first prototype ETA model of TVSS (Tactile Vision Substitution System) in early 1960’s, enormous number of research and commercial instruments are developed with visual sensory substitution. Some of these models are still available in markets with improvements (e.g. sonic torch/guide, MOWAT sensor and so on.). The user with visually impaired using these devices claimed on the difficult understanding at complex environment like in crowds and ‘sensory overload’ in use as complexity of understanding, inhibition to other sensory function.