The system consists of an EEG cap, a USB signal processor and amplifier, and a laptop running the indendiX software. The cap has eight EEG electrodes, most of which are centred on your occipital lobe -- the visual processing centre at the back of your brain.
Once you've put on the cap and attached the chest strap to pull it firmly down onto your head, you squirt conductive gel into each electrode to improve signal transmission. There's also an ear clip that acts as a reference point -- the software compares the signal from the EEGs with the baseline figure from the ear clip to compensate for background noise.
The first step is calibration. The software displays a grid of letters, and you select the letters you want to try to spell. You concentrate on the letter you want, and the software flashes horizontal and vertical lines across the grid. When your letter is highlighted there is a recognition spike in your occipital lobe -- the P300 wave that the kit detects. Telling the equipment which letter you wish to spell in advance helps the software distinguish between genuine P300 waves and background noise.
After 10 minutes of calibration it was time to spell for real! It's like Sesame Street, only instead of a giant yellow bird, it's a brain reading device.
The process is the same as calibration, but you don’t select a word in advance. We tried to spell 'wired'. It came out as 'sired' -- an impressive first attempt. Our test room has large amounts of background noise thanks to air conditioning and several wireless networks in the vicinity, so was almost a worst-case scenario for interference.
Spelling words this way is a laborious process, but the system is adaptable -- instead of a grid of letters you could have a menu or a set of locations in a house; select the kitchen to have an electric wheelchair move there automatically.
Want to give it a go? The intendiX kit costs £8,500 from OpenVivo.
Posts
No comments:
Post a Comment