There are some apps that make it seem like we live in Harry Potter’s world. Cardiio is one of those apps. By simply holding your iPhone in front of you, you can measure your heart rate in seconds.
According to their Web site, this is how it works:
“Cardiio is powered by cutting-edge research and science conducted at the MIT Media Lab. Every time your heart beats, more blood is pumped into your face. This slight increase in blood volume causes more light to be absorbed, and hence less light is reflected from your face. Cardiio uses your camera to track these tiny changes in reflected light that are not visible to the human eye and calculate your heart beat!
Measurement accuracy is within 3 beats/min of a clinical pulse oximeter when performed at rest in a well-lit environment.”