The Eye Mouse
Federal University of Pernambuco (Msc, 2008 - 2009)
"... eyes have the power to speak a great language." Martin Buber.
Eye Tracking consists in extracting some information from the human’s eyes. In this process, the final goal can be as simple as determining whether an individual’s eyes are opened or closed, or as complex as accurately determining the 3-D point in space where the subject is focusing his gaze.
When the machine becomes capable of extracting information from the human’s eyes, several applications emerge, such as;
- improvement in websites and mobile devices interfaces based on studies of user’s attention;
- enhancement in communication capabilities of physically impaired people;
- multimodal interaction in mobile devices.
Motivated to help people facing the locked-in-syndrome, a condition where the individual, although maintaining his consciousness, is unable to voluntarily control any muscle except those around the eyes, I worked with three low-cost eye tracking systems.
Eye-Tracking System 1
The first is composed by wearable glasses, with an ordinary USB webcam and an infrared LED mounted on them. After a brief calibration, this system makes the computer’s mouse to go to the position on the screen where the user is looking at with reasonable accuracy.
Eye-Tracking System 2
The second is mounted directly onto the computer screen and measures the user’s gaze vector with respect to the 3-D environment. Again, the mouse pointer goes to the point on the screen where the individual is looking at with higher accuracy in comparison with the previous approach. In addition, since the system is remote and not head-mounted, it allows a certain freedom in head movement.
Eye-Tracking System 3
Finally, the third implementation couples an eye tracking with a text prediction software. The algorithm relies only on the computer built-in camera and detects the user’s face and eyes. The pupil centers are computed and, when the eyes remain looking up for a given time, it triggers a command on the automatic text predictor software. The whole system was designed to enhance the communication capabilities of those with very strict eye movements, where the individual is able to generate only one symbol (open/ close eyes, look up/ down, etc.) when communicating.