What is some of the technology to improve Wayfinding?

Over the last thirty years, engineers have devoted considerable resources to developing electronic systems to help a person who is blind avoid obstacles; these use technology such as ultrasonics, lasers and infra-red.

Many of the devices just provided information about the range of the nearest object; a 'picture' could be built up by moving the sensor from side to side. Other devices have attempted to give a more complete image of the environment but at the expense of providing an excessive amount of information to the user who is blind.

The capacities of the senses of hearing and touch are very small compared to that of the visual channel for a human. Selecting and processing the information to make best use of the non-visual channels is not a simple task. The sensors in future devices are likely to involve more than one modality (e.g. both a video camera and an ultrasonic transceiver) in order to obtain the necessary data which can be processed to produce an accurate image of the immediate environment.

For a person who is blind, the problem of getting about is not just that of not walking into objects. One problem is that of knowing the layout of the environment; here, an embossed map can help. However, embossed maps are not easy to produce or interpret since just embossing a sighted map seldom leads to an intelligible embossed map.

Even with an embossed map and a mobility aid, it is still very easy for a person who is blind to get lost. A number of electronic orientation aids have been developed, but few have been widely used because of the cost of modifying the environment.

One type of system uses infra-red transmitters mounted at street corners; the infra-red signal is modulated so that a receiver, held by the person who is blind, gives out an audible message. These systems can also be used to indicate the status of traffic lights. Similar radio-based systems have been used in some countries, and the advent of Bluetooth is likely to dramatically reduce the cost of installing such systems.