Researchers are developing an in-car system to detect yawns and alert drivers before they nod off and kill somebody.

Aurobinda Mishra of Vanderbilt University and colleagues in India (Mihir Mohanty of ITER, in Orissa and Aurobinda Routray of IIT)  describe a computer program that can tell when you are yawning and could prevent road traffic accidents, they say.

The National Highway Traffic Safety Administration estimates that at least 100,000 road crashes are caused by driver fatigue each year.

The setup is based on an in-car camera hooked up to image-processing software that captures a sequence of images of the driver's face. It then analyses changes in the face and accurately identifies yawning as distinct from other facial movements such as smiling, talking, and singing. The yawn frequency is then correlated with fatigue behavior and could then be hooked up to a warning system to alert drivers to the need to take a break.

The algorithm is effective at yawn detection regardless of image intensity and contrast, small head movements, viewing angle, spectacle wearing, and skin color, the researchers write in the inaugural issue of the International Journal of Computational Vision and Robotics.

Similar systems have been envisioned that would rely on brain waves to detect sleepiness, but the camera setup would be less invasive than an electrode-laden helmet, the researchers point out.