A smartphone video selfie can show blood pressure

Scientists at the University of Toronto have devised a new app that works in conjunction with a smartphone camera to show several statistics about the health of the person in the image. The researchers have found that blood pressure can be measured by taking a quick video selfie. The tech in the research was co-created by Kang Lee, a professor of applied psychology and human development at the Ontario Institute for Studies in Education and Canada Research Chair in developmental nanoscience.

A postdoctoral researcher called Paul Zheng also helped develop the technology. The tech is called transdermal optical imaging, and in the research, the team measures the blood pressure of 1,328 Canadian and Chinese adults by capturing a two-minute video of their face on an iPhone. The results in the experiments were compared to standard devices used to measure blood pressure.

The team found that the tech was able to measure blood pressure with 95 to 96% accuracy. The discovery of the tech was an accident. Three years ago, the researchers were attempting to build a contactless lie detector, but in the process discovered that similar tech could measure blood pressure.

The tech works thanks to the translucent nature of facial skin. When light reaches the face, it penetrates the skin and reaches the hemoglobin in the blood underneath. The optical sensor is able to capture the reflected light from the hemoglobin and visualize how much blood is flowing underneath. The scientists formed a startup with an investor called Nuralogix.

Nuralogix developed a smartphone app called Anura that allows users to try the transdermal optical imaging software for themselves. The app enables people to record 30-second videos of their face and gives the measurements of stress levels and heart rate. In the fall, a version of the app will launch in China that measures blood pressure. More work is needed according to the team, the study didn't use people with very low or high blood pressure or those with very light or dark skin.