3D tracking system lets users control a computer with their eyes

Built using off the shelf materials at a cost of just £40, the new low power device is designed to work out exactly where a person is looking by tracking their eye movements, allowing them to control a cursor on a screen just like a computer mouse. The GT3D device is made up of two video game console cameras, each costing less than £20, that are attached, outside of the line of vision, to a pair of glasses that cost just £3. The cameras constantly take pictures of the eye, working out where the pupil is pointing, and from this a set of calibrations can be developed to work out exactly where a person is looking on the screen. The researchers have also been able to use more detailed calibrations to work out the 3D gaze of the subjects – in other words, how far into the distance they were looking. It is believed that this could allow people to control an electronic wheelchair simply by looking where they want to go or control a robotic prosthetic arm. Not only can the device transmit data wirelessly over WiFi or via usb into any Windows or Linux computer, it also uses just 1W of power and has been calibrated so that a simple wink represents a mouse click. To demonstrate the effectiveness of the system, the researchers got participants to play the classic computer game Pong. In this game, the subject used his or her eyes to move a bat to hit a ball that was bouncing around the screen. Six of the subjects who had never used their eyes as a control input before were said to have registered a respectable score within 20% of the able bodied users after just 10 minutes of using the device for the first time. Dr Aldo Faisal, a lecturer in Neurotechnology at Imperial, commented: "Crucially, we have achieved two things: we have built a 3D eye tracking system hundreds of times cheaper than commercial systems and used it to build a real time brain machine interface that allows patients to interact more smoothly and more quickly than existing invasive technologies that are tens of thousands of times more expensive. "This is frugal innovation; developing smarter software and piggy-backing existing hardware to create devices that can help people worldwide independent of their healthcare circumstances."