Triblive: After Fujitsu presented their pulse measurement system from video stream, Xerox too demonstrates a similar capability:
"Lalit K. Mestha, a research fellow at Xerox's research center in Webster, N.Y., demonstrated the technology at a media event last week in Xerox's PARC research lab in Palo Alto, Calif. While Mestha was sitting about 10 to 15 feet across the room, one of his Xerox colleagues pointed a webcam at his forehead and quickly was able to get a read on his pulse."
"When light hits human skin, some of it penetrates as far as 1 centimeter, Mestha explained. The light interacts with blood vessels, and the wavelengths of light reflected from below the skin varies as blood pulses through the vessels. Those changes can be detected by the image sensor in a standard webcam."