“The pulse oximeters used in emergency rooms, ambulances, and home care effectively measure blood oxygen, but that actually doesn’t change much until you’re basically near death,” says Brian Pogue, Dartmouth’s Robert A. Pritzker Professor of Biomedical Engineering and co-author of the study.

“What we really want is not the blood oxygen, but the tissue oxygen. That’s a much more subtle indicator of tissue function and a better dynamic indicator of health.”

Current methods for measuring tissue oxygen involve expensive camera systems or require extra sensors injected into the body or attached in an inpatient setting. The research team based in Dartmouth’s Thayer School of Engineering uses a regular cell phone camera paired with a pulsed LED light and a topical activation cream.