Brainwave communication

A system that allows people with severe brain injuries to communicate using only eye movements and the power of thought is being developed by a researcher at Portsmouth University.

Dr Paul Gnanayutham, senior lecturer in the School of Computer Science and Software Engineering, developed the communication interface for patients whose injury has left them unable to speak and motor-impaired.

The system is inspired by a gaming interface and consists of three electrodes — the same as used for ECG — attached to the forehead. These pick up tiny voltages from the brain, which are then sent to a box that filters and amplifies them.

The resulting signal is fed into the parallel port of a PC to control a cursor on the screen.

‘It’s hard to control thoughts and words, so we split the screen into tiles or stepping-stones,’ said Gnanayutham. ‘These could be a simple yes and no, or up to six targets, spread in areas the patient can access.’

Gnanayutham tested his system with five patients at the Holy Cross Hospital in Haslemere, Surrey, which works with people with severe disabilities.

One woman was unable to move her eyes or forehead but, by using thought alone, could answer yes or no to questions. A man injured in a mountain climbing accident could navigate the screen more clearly and had six targets to chose from. This was used to enhance his daily routine, gathering information on what he would like to do at different times of day.

‘The concept is nothing new — brain waves were discovered in 1925,’ said Gnanayutham. ‘I want to create an affordable, portable device that people could buy off the shelf and set up without any experts needing to be there.’