This phone case can measure blood pressure

Samsung, in partnership with the University of California, San Francisco (UCSF), will introduce an app on March 15, or, a day before the official S9 launch, which will let you log blood pressure readings made solely with the new and improved heart rate sensor on the back of the S9. There are plenty of apps in the Play store that use your camera and LED flash illumination to try and analyze the pressure readings. These usually show blood pressure that is too low, so Samsung's approach with the heart rate sensor may take precision a step up. 

The blood pressure reading case in question uses a sensor as well, and an app that tells you how much pressure to apply on it, thus measuring the cut in blood flow to the finger, and extrapolating blood pressure readings. Co-developed by Ramakrishna Mukkamala, a professor at Michigan State University’s College of Engineering, the case took volunteer participants only two ties on average to start taking BP measurements. 

Compared to finger cufflinks it was at least as accurate, but arm cuffs deviated from its results, so there is still work to be done when it comes to precision. The researchers patented the technology, and licensed it to Digitouch Health, so hopefully we'll have a commercial device launched soon, as it's a drag to lug around blood pressure measuring cuffs.

source: Science