Worcester Polytechnic Institute (WPI) researchers have developed a smart phone app that can measure heart rhythm and rate, respiration rate, and blood oxygen saturation using the phone’s built-in video camera.

As the camera’s light penetrates the skin, it reflects off pulsing blood in the finger. The app can correlate subtle shifts in the color of the reflected light with changes in the patient’s vital signs. Measurement of respiratory rate uses an algorithm developed for use with a pulse-oximeter, based on amplitude and frequency modulation sequences within the light signal.

The app yields vital signs as accurate as standard medical monitors now in clinical use, according to Ki Chon, professor and head of biomedical engineering at WPI. “It allows patients to make baseline measurements at any time, building a database that could allow for improved detection of disease states,” he said.

The researchers are also developing an app to detect atrial fibrillation, the most common form of cardiac arrhythmia, and a version for tablets like the iPad2.

Ref.: Scully, C. et al., Physiological Parameter Monitoring from Optical Recordings with a Mobile Phone,IEEE Transactions on Biomedical Engineering, 2011; [DOI: 10.1109/TBME.2011.2163157]