Eye-pad of the future Paralysed patients could 'talk' by using their pupils like a pencil to write sentences



10:54 GMT, 27 July 2012

Patients who have lost the ability to move could soon be able to communicate by 'writing' with their eyes.

Researchers have created a new technology that trains people to move their pupils in a smooth cursive motion and then traces these words onto a screen.

Our eyes never cease to move and it is normally impossible to control those movements smoothly in any direction.


Professor Lorenceau

Dr Lorenceau wearing his head-mounted display

However, a team led by Jean Lorenceau of Universit Pierre et Marie Curie-Paris realised they could effectively trick the eye muscles to voluntarily produce continuous movements.

Dr Lorenceau said: 'Contrary to the current belief, we show that one can gain complete, voluntary control over smooth pursuit eye movements.

'The discovery also provides a tool to use smooth pursuit eye movements as a pencil to draw, write, or generate a signature.'


Examples of digits, letters, words and drawings using the new display

Examples of digits, letters, words and drawings created by eye movements using the new display

The scientist found that after just a few half-hour training sessions healthy volunteers could write words onto a screen at a rate of 20-30 characters per minute. This is similar to normal handwriting.

The advance could be of great benefit for people deprived of limb movements, such as those who cannot move following a stroke or suffer from conditions such as motor neurone disease.

Dr Lorenceau said they would be able to use the device to 'enjoy a personal and emotionally rich way of communicating with others.'

The team got a hint that smooth
eye movements just might be possible by accident. Dr Lorenceau
was moving his own eyes in front of an unusual visual display in his lab
and discovered that it produced some odd effects.

For one thing, he
could see his own eye movements and with a little practice, he gradually
discovered that he could control them.

Using this experience, the team developed a technique that harnessed the strange illusion. They created a flickering screen filled with static discs at different contrast levels. When viewing the discs directly they appear still but when the gaze is shifted they then appear to move in the same direction.

Lorenceau reported in Current Biology: 'After brief training, participants gain volitional control over smooth pursuit eye movements and can generate digits, letters, words or drawings at will.'

He said the device could also help
to improve eye movement control in people with certain conditions such
as dyslexia or ADHD and for experts, such as athletes or surgeons,
whose activities strongly rely on eye movements.

Lorenceau is now working on a better version of his eye writer, and tests with patients with neurodegenerative disease should start next year.