When Rice University graduate student Mayank Kumar and colleagues visited Texas Children’s Hospital in 2013 they took note of the tangle of wires attached to premature infants to monitor their vitals. The wires frequently had to be removed or adjusted, which can potentially damage the preemies' delicate skin, whenever mothers fed or cared for the babies.
So Kumar and Rice University professors Ashok Veeraraghavan, PhD, and Ashutosh Sabharwal, PhD, developed a video camera-based system that measures patients' pulse and breathing by analyzing the changes in their skin color over time.
The system, called DistancePPG, corrects for challenges that have caused similar technology to be unreliable such as low-light conditions, dark skin tones and movement. According to a university release:
The Rice team solved these challenges 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.
“Our key finding was that the strength of the skin-color change signal is different in different regions of the face, so we developed a weighted-averaging algorithm,” Kumar said. “It improved the accuracy of derived vital signs, rapidly expanding the scope, viability, reach and utility of camera-based vital-sign monitoring.”
By incorporating tracking to compensate for movement — even a smile — DistancePPG perceived a pulse rate to within one beat per minute, even for diverse skin tones under varied lighting conditions.
Kumar said he expects the software to find its way to mobile phones, tablets and computers so people can reliably measure their own vital signs whenever and wherever they choose.
There's more about how the system works in the above video.