SWAN to Enable People with Visual Disabilities Handle New Terrain

A computerized tracking system is being developed to guide people with visual disabilities through unfamiliar territory like a city street by giving audio cues. System for Wearable Audio Navigation or SWAN is a prototype system that makes use of satellite technology.

The device uses information from two or three GPS trackers, four cameras placed on the user’s body, a digital compass, a light sensor and a head tracker which works out which way the user is facing. A laptop carried in the rucksack processes the information and directs them on their desired route through a virtual representation of the landscape.

The device passes information to the user by sending sound signals, produced by so-called “bone microphones”, via vibrations through the skull. The bone microphones are adjusted so that the user experiences a pinging sound that seems to originate from a point which is a meter away from them in their desired direction of motion.

“You bypass the normal hearing mechanism and you create the same perceptual phenomenon through a different way,” said Bruce Walker, one of Swan’s developers at the Georgia Institute of Technology in the US. The scientists are planning to produce a system using tiny cameras which can be placed in eye glasses or a lapel pin.

Two kinds of sounds are produced by these microphones. One is a repeated pinging beacon that guides the user to location of their choice. The alternative is a pedestrian version of car satellite navigation that is currently used in other systems already available in the market. Other sounds include those assigned in the device for recognizing objects like lampposts or post boxes. These signature sounds seem to come from the objects relative to the user.

The researchers say Swan could also be used by firefighters and soldiers in situations where visibility is impaired.

Source: Georgia Institute of Technology