Google Pixel phones will soon track your heart rate using only the camera

The latest exclusive feature of Google Pixel is the ability to track your heart and breathing rate without any extra hardware. The company says that starting next month, Google Fit on Pixel phones will track these health statistics using only the devices’ existing cameras.

We’ve seen heart rate tracking on smartphones before, thanks to Samsung’s Galaxy line. From the Galaxy S5 to the Galaxy S10, Samsung monitored the heart rate using a physical photoplethysmography (PPG) sensor on the back of the phone. Users can simply press a finger against the sensor and get a heart reading in seconds.

Pixel phones don’t have PPG, but Google’s solution is not that different. A PPG turns on a light (usually a green LED) on your skin, which is reflected by your bloodstream back to a nearby photoreception. It is basically a specialized camera. Google’s Pixel solution uses only the real camera. Google says, “To measure your heart rate, just place your finger on the lens of the rear camera.”

The breathing rate calculation uses the front camera. Google’s instructions (shown in the gallery, above) say to support the phone on something, turn on the selfie camera, and as long as your head and torso are in view, you can get a heart rate and breathing rate – reading the rate.

What we learned from previous Samsung smartphones was that it is better to leave heart rate tracking to smartwatches and fitness trackers. Wearables are in contact with your arm at all times and can passively monitor your heart rate while you exercise or during the day. The phone-based solution requires you to stop what you’re doing, open an app, press your finger against a sensor and hold it still for a few seconds while it takes a measurement. On Samsung phones, this was a nuisance and definitely not something you would want to do in the middle of a workout. Samsung also gave up on the feature, cutting the Galaxy S20’s PPG sensor, and no one missed it. The feature makes a little more sense when it’s “free” and doesn’t require any special hardware, but we still prefer to just use a fitness tracker, especially when decent PPG trackers 24/7 can be purchased for $ 30.

Google says these two features track “tiny physical signals at the pixel level – like chest movements to measure your breathing rate and subtle changes in the color of your fingers to your heart rate”. Google told The Verge that the heart rate sensor is accurate to 2%. The company does not have FDA approval for any of these new features, so they are for “general well-being” only and cannot be used for a medical diagnosis or to assess medical conditions.