A new set of software algorithms can amplify aspects of a video and reveal what is normally undetectable to human eyesight, making it possible to, for example, measure someone’s pulse by shooting a video of him and capturing the way blood is flowing across his face, Technology Review reports.

The software process, called “Eulerian video magnification” by the MIT computer scientists who developed the program, breaks apart the visual elements of every frame of a video and reconstructs them with the algorithm, which can amplify aspects of the video that are undetectable by the naked eye.

These aspects could include the variations in redness in a man’s face caused by his pulse.