Practicability verification of a visual aid system for the visually impaired

We developed an artificial visual aid system for the visually impaired using a passive type stereovision unit that incorporates a laser line marker as a supplementary light source. In this visual aid system, the distances to 24 points are measured in a linear direction using a triangulation method and the distance data conveyed to the visually impaired user through variation in the frequency of a piezoceramic oscillator Though the technique of conveying distance information to the user via changes in frequency is commonly used, its effectiveness has not been clarified. Therefore, as a guideline for verifying the practicability of the system developed, we set up a scenario in which a subject walked through a subway station using the newly developed system, actual visual information on the station was collected and this data was then conveyed to the subject enabling him to make decisions on where to walk. The results of this experiment verified the practicability of the newly developed system.