07 Oct 2004
Mobile Eye from ASL offers a convenient way to analyze the performance of sportsmen in action.
US eye-tracking specialist Applied Science Laboratories (ASL) has released a portable headset device about the size and weight of a pair of sunglasses. The system uses a belt mounted recording device to store data on the move and is as much at home on the golf course as in a flight simulator.
The technology relies on a low power infrared light source and a pair of miniature cameras to see where the user is looking.
"The pupil acts as a light sink, absorbing the light. It becomes the darkest spot on the [output] screen, making it easy to discriminate from other parts of the eye," ASL engineer Kim Hammel told Optics.org. "Corneal reflections are generated by a series of three small LEDs located [on the headset] just above the eye." By monitoring the pupil's location relative to the position of these corneal refelections, the unit can determine the wearer's point of gaze.
According to Hammel, the Mobile Eye's compact size is mainly due to the availability of small lightweight cameras. The unit features two - one showing an image of the eye and the other showing the field of view. Because the output field of view is superimposed with cross-hairs showing the point of gaze, you can see exactly where the user is looking.
The fact that the head-unit weights just 80 g and supports full motion of the head makes it an attractive option in sports analysis and coaching situations such as teeing off in golf, free throws in basketball or taking penalties in football. "You can put this on an expert, record the pro's eye movements and then teach them to a beginner," said Hammel. "Marketing people are also interested in the systems to see how people interact with websites."
ASL, based in Massachusetts, has been developing eye-tracking systems for 30 years and has customers across a number of market sectors such as medicine, cognitive science, biomechanics, training and simulation. For example, NASA and Boeing have been using ASL's eye-tracking for a number of years to examine the way people acquire and react to visual information.
Mobile Eye saves its interleaved eye and scene data on a 75 minute DVCR tape recorder powered by a rechargeable battery. The completed tape is transferred to a PC to generate the scene video complete with cursor overlay. Supplied with all necessary hardware and software the Mobile Eye system costs around $20,000.