Echolocation device enables blind to ‘visualise’ environment

Blind people could be given a ‘second sight’ by scientists at Leeds University with an invention based on the echolocation of bats. The ‘Spatial Imager’ emits ultra sound in exactly the same way as bats do to manoeuvre their way around obstacles in the dark. The device causes a small vibration to fingers corresponding to where the obstruction is, providing the user with a ‘tactile map’ of their environment.

The idea was sparked by a chance conversation between a group of academics at the University - Deborah Withington, a neurophysiologist, Dean Waters, a biologist and bat expert, Brian Hoyle, an electronics expert and food scientist Malcolm Povey.

"Malcolm was talking about how ultra sound is used in the food industry to detect something as small as a bruise on an apple in a batch, and I asked whether ultra sound could be used in a tactile way." said Professor Withington, whose research specialises in human sensory systems.

Professor Withington believes the device would be more effective than the conventional white stick because it would give a wider area of spatial awareness, not only detecting obstacles in front of and around the user, but also those that hang from above. In addition, the range of the device’s ultra sound could be altered to suit the user’s requirements. The device could fit onto a stick or more discreetly into a glove - "It would depend whether the recipient wanted other people to be aware of their disability or not," she said.

The sense of hearing also is an important navigational tool for both the sighted and the blind. However, current devices give audible warnings of obstructions, usually through earphones. By using the sense of touch instead, the Spacial Imager provides an extra dimension, freeing the sense of hearing to be used as normal.

The Spatial Imager could also be of use to the fire brigade and police divers in situations where visability is impaired. For example, firefighters entering smoke filled environments could be guided around any obstructions, as could underwater search teams diving in murky waters.

The academics have formed a company, Sound Foresight Ltd, to develop the concept further. The invention has won a Smart Award for innovation from the Department of Trade and Industry to fund a prototype and further research. The company hopes the device will be commercially available within two years and the RNIB has expressed an interest in its development.