Eye Trackers

Eye tracking devices are communication and control systems that monitor eye movements and allow people with total loss of mobility and speech to control a computer or mobile device by eye movement alone.

Special software allows a person to type by looking at control icons or data displayed on the screen, and may include text completion technology to speed up the typing process, as in today’s smartphones. The user can also generate speech by typing a message or selecting from multiple phrases.

For example, the DynaVox EyeMax system uses eye-tracking technology for computers, watching TV, reading books, and talking for people with limited mobility. The device’s camera tracks the user’s eye movements, allowing them to use the device simply by blinking or looking into their eyes. At the same time, DynaVox offers a wide range of tools and applications for people who need help communicating.

These systems are expensive, so they are less common than less sophisticated devices, but technology is evolving both in terms of their development and price.

Chinese scientists at Tsinghua University have developed a noninvasive brain-computer interface with the fastest eye-movement-to-data conversion rate to date. The system uses a very precise measurement of changes in frequency and phase of potentials in the brain caused by eye movement, through which the voice system can determine the direction of the user’s gaze directed at a particular letter.

Scientists have developed a new method of frequency-phase modulation and a user-configurable algorithm that allows synchronous modulation and demodulation of electroencephalogram data. This enables the user to communicate at a rate of up to 60 letters per minute (approximately 12 words), which was hitherto unattainable.