A number of inappropriate navigation devices have been foisted onto the visually impaired population over the past twenty years. These portable electronic devices are usually mounted on a long cane adaptation, or hand-held by the visually impaired user. Their function is primarily to help prevent a collision with an obstacle in the immediate path. Some of these navigation devices use laser technology to gauge subject-to-object distance. Others use infrared transceivers or ultrasonic pulse-echo techniques to locate and warn of obstacles. Some extend their role beyond giving warning signals, to crudely assisting the user map the immediate path ahead. These devices exhibit a number of problems, the most significant of which are related to the interface display that conveys navigation/obstacle warning information to the blind user. As sound is often used in these
displays, the vital auditory channel is typically compromised.
The author has produced a solution, which is at an early
stage of development. Several successful prototypes using
tactile displays, have been produced