"MIT discovers yet another use for a simple webcam: measuring your pulse rate. It's desktop video-chatting and heart physician in one tiny unit.
The work is the result of studies by graduate student Ming-Zher Poh, and it's all about a clever algorithm that looks at a webcam feed of your face and measures subtle brightness changes in your skin over time. It's possible, Poh found, to calculate the pulse rate of a person on camera by using a public-domain face-tracking solution and then examining the different color channels of a face in a video feed. The trickiest part wasn't even the pulse detection, but accounting for all the lighting and color effects as the subject's face naturally moved in the ambient lighting conditions. Overcoming this involved adapting algorithms from those in voice recognition systems that isolate a particular voice from a room of other voices."
Read the whole thing.
I can see additional uses for this technology that have severe privacy implications, such as checking the pulse and respiration rates of everyone passing through an airport security line.