October 8, 2010 | by Lars Aronsson
There are certain innovative apps that manage to impress you the first time you use them and make you wonder exactly what goes on behind the scenes. A few examples are the classic music identifying service Shazam, and Plink Art (now a part of Google Goggles) that automatically gives you information about virtually any known painting when you snap a photo of it. Another original application that you may already have heard of, not least since it currently is a featured app in the Market, is Instant Heart Rate.
By softly placing your finger on your phone’s camera lens for around 10 seconds, the app successfully measures your current heart rate. The mechanics that enable this trick are explained by the developers: apparently, the software tracks color changes in the light that passes through your finger.
With every heartbeat, your blood gets more oxygen rich and that causes the color of your skin to change, if ever so little. The app measures these changes and calculates your heart rate based on them. Of course, this may not be an app that you will have much practical use for unless you for some reason need to check your heart rate often, but it’s cool nonetheless and worth giving a try if you haven’t already.