A.C. Kooijman and M.T. Uyar

Laboratory of Experimental Ophthalmology, School of Behavioral and Cognitive Neurosciences,
P.O.Box 30001,
9700 RB Groningen,
The Netherlands.

The development of electronic systems for communication and mobility is encouraged by evolving technologies. Some of these developments aim directly at the use by visually impaired people, other are destined for general application. Examples are artificial retinal and cortical implants, ultrasonic navigation aids, GPS and IR travel aids, vocal computer communication, etc..Some examples of these developments will be shown with some emphasis on travel aids. The results of a study of a new type of IR travel aid (EW) will be presented in comparison with another IR travel aid (BOS) and with passer-by travel assistance.

BOS is a talking sign post which points to a selection of destinations; EW is a talking route system that guides the user to the destination which is entered into the personal receiver at the start. Both systems make use of ceiling mounted beacons and infra-red communication between the beacons and the personal receiver. Twenty five visually impaired subjects used each system to walk four indoor routes. Results were compared to the way-finding performance after a verbal route description by a passer-by.

The time to cover the routes was significantly longer (146%) with the use of BOS and shorter (88%) with EW compared to the time needed after a verbal route description. It was easy to use system EW in combination with a guide dog. The number of times that additional information was needed or correction was given differed significantly between the systems. In reply to our question the subjects in our population declared unanimously to prefer the use of an electronic route system at a future visit to the hospital above a verbal route description.

The functionality of the two systems differed significantly in these test conditions. BOS prolonged considerable the time to walk along a route due to the time needed to hear the instructions at each junction in the route. This is in strong contrast to the results with EW: the subjects covered the routes 40 percent faster than with the use of BOS. We did not test the ease to handle the systems in daily use. It can be anticipated that for some people the handling of BOS might be simpler than the handling of EW. For those people BOS might present a good alternative to EW to find the way independently.

Route systems may not only be useful for visually impaired people, but also for people with topographical disabilities and for people without significant impairments to find their way in complex buildings, museums and cities.