Check out this website I found at
newscenter.philips.com
How it works
Your heartbeat causes small changes in the color of your face. These changes are not visible to the eye, but with advanced software the iPad 2 camera detects these ‘micro-blushes’ to measure your heart rate. When you breathe, your chest moves up and down. With advanced software, the iPad 2 camera tracks the movement of your chest to measure your breathing rate.
The App offers iPad 2 users the possibility of simply measuring their heart rate and breathing rate in the comfort of their home*. The App offers the option to immediately share your results via Facebook, Twitter or e-mail.