Navigation tool offers virtual world for the blind

Researchers at the University of Rochester have created a navigational assistant that can help inform visually impaired people of their whereabouts, or even bring new dimensions to museum navigation or campus tours for sighted individuals.

The system, nicknamed 'NAVI' for navigational assistance for the visually impaired, uses radio signals to gauge when someone is near passive transponders that can be as small as a grain of rice and located on the outside of a building, on a specific door inside, or on a painting or object of interest.

The system works like the security tags that are frequently on items in retail stores, or those used by certain petrol stations and fast-food chains that allow users to wave a tiny wand near a detector on a browser or cash register. In these circumstances, a radio signal is beamed from the detectors by the door, bowser, or cash register and is picked up and returned by a tag within a certain range. The security tags simply set off an alarm, while other tags can encode information, allowing the reader to debit an account for the sale.

The engineering students decided to make the reader portable and affix the tags to stationary objects, like buildings. The system can then use the encoded information to make possible an assistance device for the blind. They built a piece of equipment that was essentially a portable detector coupled to an audio playback device.

The students decided to connect a portable CD player to the device, programmed to play a particular track through an earphone whenever a certain tag was detected. It could be a simplistic message such as "Mr Smith's office door", to an elaborate discussion of a piece of art in a museum, or the history of a building on a self-guided campus tour. Using a CD player would allow a person to switch CDs for different purposes and locations; for instance, there may be a CD for getting around a city, complete with street names and structures of interest, or another to guide a user throughout an office building.

Future incarnations of the device could store information in solid-state memory that could be updated automatically when entering a new building, or allow people to lay out their own tags and record relevant information for each.