Ming-Zher Poh who is a MIT student studying Electrical and Medical Engineering has created a Medical Mirror using a cheap camera as the medical sensor. The camera doesn’t have to be anything special, the cheap webcam in your laptop would do just fine. It is looking for a person and tracks their face. Once it is locked onto the face it monitors the slight changes caused by blood flow.
“Public-domain software is used to identify the position of the face in the image, and then the digital information from this area is broken down into the separate red, green and blue portions of the video image. Poh continues to work on developing the capability to get blood pressure and blood-oxygen measurements from the same video images. Extracting such data from optical imagery should work, he says, since conventional blood oxygen sensors already work by using optical detection, although they use a dedicated light source rather than ambient lighting.”