New technology enables writing with the eyes

In the future, celibates could quickly and easily paint numbers, words, and any shapes

Shown are unprocessed examples of numbers, letters and words that have been written by eye movements using a new technique. © Lorenceau et al., Current Biology
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A new technique opens up completely new ways of communicating to the whole body paralyzed: in the future they will be able to paint letters, words and numbers on a display simply by their eye movements. The technology for this has now been presented by a French brain researcher in the journal "Current Biology". So far, this type of writing was impossible because the pupils usually perform twitching, involuntary movements. These so-called saccades prevent camera programs from tracking and recognizing fine targeted movements of the eyes. In the new method, a blinking screen background prevents the saccades.

Already after a short training subjects would have learned to control their eye movements and generate readable forms, the researchers reported. For people who can no longer move their limbs, this is a quick and easy way to express themselves verbally and creatively.

So far, all over the body paralyzed people who can no longer speak, communicate very slowly and cumbersome with their environment: they look for a computer display with all the letters of the alphabet and then have to sequentially fix each letter for a moment and confirm by flashing. "The new technology now offers these people a whole range of opportunities they have not had before, " writes Jean Lorenceau of the Pierre et Marie Curie University in Paris. So they could draw any shapes or sign something like a pencil. With a little practice you could also write 20 to 30 letters per minute with your eyes, that's as fast as with your hand.

The researcher is currently working on improving his system. But next year, he announces, first tests will be done with patients suffering from amyotrophic lateral sclerosis (ALS). In this incurable disease, the nerves that control the muscles are progressively destroyed. As a result, patients suffer from increasingly severe paralysis and can not talk after some time. Eye writing could help them communicate better with their environment than before, says Lorenceau.

Flickering circles deceive the visual system

The core of the new system is a screen background with numerous randomly distributed circles. They change their contrast 720 times a minute, creating a quick flicker. "When the eyes are steady, this background only appears as a field of static disks, " explains Lorenceau. But if you move your eyes, this flickering creates a pseudo-movement: the circles seem to wander in the direction of the eye's movement. This effect fills the visual system and ensures that the saccades are omitted, as the researchers reported. display

A special camera and a computer program evaluate the eye movements of the "writing" person and determine the painted form. To facilitate the training, initially marks a ring of colored dots, where the gaze of the subject just goes. "It should be said that users do not immediately see the lines created by their eye movements, " explains Lorenceau. They therefore need to learn to write, so to speak, blindly. But this is surprisingly fast: After only three half-hour training sessions in front of such a display six subjects, numbers, letters and whole words learned to write legibly. (Doi: 10.1016 / j.cub.2012.06.026)

(Current Biology, 27.07.2012 - NPO)