The Xiaomi Mi 11 flagship smartphone was unveiled in China yesterday as the first Snapdragon 888 smartphone. Mi 11 also comes with a 2K 120Hz AMOLED display, 108MP camera, and 50W wireless charging. One of the features that many may overlook is the in-display optical fingerprint sensor.
It has become commonplace in AMOLED display phones. But the in-display optical fingerprint sensor aboard the Mi 11 apparently doubles as a heart rate monitor as well.
Mi 11 Fingerprint Sensor Works As Heart Rate Monitor
Now, as seen in the tweet below, this optical fingerprint sensor makes Xiaomi’s 2021 flagship smartphone stand out as it’s capable of heart rate monitoring. Yes, you will be able to measure your heart rate using the fingerprint sensor on the Mi 11.
— Goodix (@GoodixTech) December 28, 2020
Now, for those wondering – how can the optical fingerprint sensor be used for heart rate monitoring? Well, if you know the basics, an optical fingerprint sensor works by clicking pictures of your fingers using a tiny camera under the display. And as XDA Developers points out, heart rate monitoring works in a similar manner.
Most fitness bands and watches these days feature a PPG heart rate sensor. PPG stands for Photoplethysmography. This is an optical method that uses a light source (which can be the MI 11’s AMOLED display) and a photodetector (camera under the display) to measure blood circulation. Goodix appears to have figured out how to take multiple photos in quick succession and calculate the variation in blood circulation.
Xiaomi already provides a heart rate monitoring feature via the Mi Health app, which made its debut with MIUI 12 skin earlier this year. It uses the camera and LED flash to measure a user’s heart rate. It is possible that the company has configured the app to work with Goodix’s fingerprint sensor as well.