WASHINGTON, Aug. 6 (Xinhua) -- Blood pressure monitoring might be one day as easy as taking a video selfie with a smartphone, according to a research report published Tuesday in a professional U.S. journal.
The study released in the American Heart Association journal Circulation: Cardiovascular Imaging showed that a tool in a smartphone could measure blood pressure by detecting blood flow changes in facial videos, enabling a contactless and non-invasive blood pressure monitoring method.
Researchers from the University of Toronto measured the blood flow of 1,328 Canadian and Chinese adults by capturing two-minute videos using iPhones equipped with transdermal optical imaging software.
The light penetrates the outer layer of their skin, which allows digital optical sensors in smartphones to visualize and extract blood flow patterns, according to the study.
They compared the smartphone-captured systolic and diastolic pressure measurement to blood pressure readings with a traditional cuff-based device. They found that on average, the transdermal optical imaging predicted systolic blood pressure with nearly 95 percent accuracy and diastolic blood pressure at nearly 96 percent accuracy.
The limitations of the study include that participants' faces are videoed in a well-controlled environment with fixed lighting and none of the skin tones are extremely dark or fair.
The researchers are also working on reducing the needed video length from two minutes to 30 seconds, in order to make the technology more user-friendly.