Communication via eye blinks and eyebrow raises: video-based human-computer interfaces

Two video-based human-computer interaction tools are introduced that can activate a binary switch and issue a selection command. BlinkLink, as the first tool is called, automatically detects a users eye blinks and accurately measures their durations. The system is intended to provide an alternate input modality to allow people with severe disabilities to access a computer. Voluntary long blinks trigger mouse clicks, while involuntary short blinks are ignored. The system enables communication using blink patterns: sequences of long and short blinks which are interpreted as semiotic messages. The second tool, EyebrowClicker, automatically detects when a user raises his or her eyebrows and then triggers a mouse click. Both systems can initialize themselves, track the eyes at frame rate, and recover in the event of errors. No special lighting is required. The systems have been tested with interactive games and a spelling program. Results demonstrate overall detection accuracy of 95.6% for BlinkLink and 89.0% for EyebrowClicker.