Are stethoscopes on their way to becoming obsolete? It's possible, as scientists from Utah State University have developed a no-contact method of measuring a person's heartbeat utilizing a video camera and custom software.

The system is based on the fact that our skin subtly changes color as our heart beats, in a manner that can't be seen by the human eye but that can be detected by a camera.

"Hemoglobin in the blood has an absorption peak for green light," says Dr. Jake Gunther, who teamed up with his former student Nate Ruben to create the technology. "So when the heart pushes blood into arteries near the skin, more green light is absorbed and less is reflected. This means we see fewer green values in the images from the camera."

The software not only processes the color data, but it also computes an average over regions of the body where the skin is visible, such as the face, neck or arms. It is hoped that the patented system could find use in applications such as baby monitors, exercise equipment and even hospital settings.

The technology is being developed for commercialization via startup company Photorithm Inc. It may have some competition, however, as both EPFL and Ben-Gurion University have recently developed similar systems.