Researchers from Rice University are developing an accurate, touch-free system that uses a video camera to monitor patients’ vital signs just by looking at their faces. The technique isn’t new, but researchers in Rice’s Scalable Health Initiative are making it work under conditions that have so far stumped earlier projects.

Called DistancePPG, the system can measure a patient’s pulse and breathing by analyzing the changes in one’s skin color over time. It can work in low-light conditions, and with dark skin tones and movement, relying on algorithms that correct for those variables. This, according to the project authors, was accomplished by adding a method to average skin-color change signals from different areas of the face and an algorithm to track a subject’s nose, eyes, mouth and whole face.

The system can work in low-light conditions, and with dark skin tones and movement, relying on algorithms that correct for those variables.The team of Rice, consisting of a graduate student Mayank Kumar and professors Ashok Veeraraghavan and Ashutosh Sabharwal, hopes that their system will let doctors diagnose patients from a distance, helping them reach underserved populations. Additionally, DistancePPG can also be helpful to monitor premature infants for whom blood pressure cuffs or wired probes can pose a threat.

The current DistancePPG installation requires a computer, but going forward the software will most likely find its way to mobile phones and tablets, so that people can reliably measure their own vital signs whenever and wherever they choose.

The National Science Foundation, the Texas Instruments Fellowship, the Texas Higher Education Coordinating Board and a Rice University Graduate Fellowship supported the research.