How the Samsung Galaxy S5 Measures Your Heart Rate

One of the many new features in the Samsung Galaxy S5 smartphone is a heart-rate sensor. Built into the phone next to the camera flash, the sensor can read a person's heart rate when he holds his finger up to it for a few seconds.

The technology that Samsung uses isn't new, but it's the first time we've seen it in a smartphone. It works by shining the phone's LED light on your fingertip, letting the sensor detect the blood flow beneath the skin.

We had a chance to try out the S5's sensor at Samsung's New York unveiling of its new products, and it seems to work quickly — and well. You could question the practicality of a heart-rate sensor that requires positioning your finger on the phone in a non-natural way, versus a sensor you can wear on your chest or wrist (all the new Samsung Gear smartwatches also boast heart-rate sensors), but it's a neat trick you can't do with any other phone. Yet. Read more...