zher

Here's the link to the study published in The Lancet Global Health: http://www.thelancet.com/journals/langlo/article/PIIS2214-10...

that's right. what you're looking for is the transient changes (AC) in color due to increase blood perfusion whereas a person's baseline skin color can be considered the DC component.

thanks for catching that!

Yes, it's hard to believe, but it's really possible to sense the small color changes due to blood flow in the face using cameras. My earlier work described how you just need a simple webcam :)(http://web.mit.edu/newsoffice/2010/pulse-camera-1004.html). As a result, I'm working on Cardiio (http://cardiio.com) to bring this technology to both the web and mobile very soon. If you're interested in computer vision based biosensing, please sign up!