Seeing the human pulse

Researchers at MIT's Computer Science and Artificial Intelligence Laboratory have developed a new algorithm that can accurately measure the heart rates of people depicted in ordinary digital video by analyzing imperceptibly small head movements that accompany the rush of blood caused by the heart's contractions. In tests, the algorithm gave pulse measurements that were consistently within a few beats per minute of those produced by electrocardiograms (EKGs). It was also able to provide useful estimates of the time intervals between beats, a measurement that can be used to identify patients at risk for cardiac events. Guha Balakrishnan, a graduate student in MIT's Department of Electrical Engineering and Computer Science, and his two advisors -- John Guttag, the Dugald C. Jackson Professor of Electrical Engineering and Computer Science and director of MIT's Data-Driven Medicine Group, and professor of computer science and engineering Fredo Durand -- describe the new algorithm in a paper appearing this summer at the Institute of Electrical and Electronics Engineers' Computer Vision and Pattern Recognition conference. A video-based pulse-measurement system could be useful for monitoring newborns or the elderly, whose sensitive skin could be damaged by frequent attachment and removal of EKG leads.