Because of its translucency, phone optical sensors can capture red light reflected from hemoglobin under skin, allowing TOI to visualize and measure blood flow changes.
In a study, two-minute iPhone selfie videos of 1,328 adults were analyzed. Three types of blood pressure were measured with 95 percent accuracy. Pre-recorded videos can also be used.
The technology is being commercialized through Nuralogix, a company founded by Lee and Zheng, which is already measuring resting heart rate using videos.
Click to view University of Toronto video.