How'd you like to check your pulse, respiration, and blood pressure as you brush your teeth in the mirror each morning? A PhD candidate at the Harvard-MIT Division of Health Sciences and Technology is working to make this a reality in the near future.
Electrical and medical engineering student Ming-Zher Poh has already used low-res Webcam imaging to measure the human pulse. He's now working on adding respiration, blood oxygen levels, and blood pressure to the list--all by having people simply peer into a camera or, for those who'd rather multitask, into a mirror in front of that camera.
The system works by measuring the slightest variations in brightness produced by blood flow through blood vessels in the face. Poh used public-domain software to identify facial positions in any given image and break that information into separate red, green, and blue portions of the video images.
To deal with both movement in front of the lens as well as different ambient light, Poh adapted a method known as ICA (Independent Component Analysis)--a signal-processing technique originally developed to extract a single voice from a room of conversations--to find the pulse signal amid all the video noise.
The pulse results turned out to be pretty reliable when compared with measurements taken by an FDA-approved monitoring device.… Read more