Xiaomi Mi 11’s fingerprint scanner doubles as a heart rate monitor
One of the standout features of the new Xiaomi Mi 11 is the inclusion of an in-display fingerprint sensor. In a world of face masks, the feature makes unlocking the device much easier, but that’s not actually why the feature is interesting. The fingerprint sensor doubles as a heart rate monitor.
The Xiaomi Mi 11 has an optical under-display fingerprint scanner like many other flagship smartphones, and that fingerprint scanner is supplied by Chinese vendor Goodix. Following the device’s announcement, Goodix PR reached out to us with the following statement.
“With the launch of Xiaomi Mi 11, I’m happy to share that Goodix’s ultra-thin optical IN-DISPLAY FINGERPRINT SENSOR™ again successfully was applied on this brand-new flagship. Its ultra-thin form factor opens up more internal space of slim body of Mi 11 while not compromising its excellent performance…A quick update about the ultra-thin optical IN-DISPLAY FINGERPRINT SENSOR™ it enables the heart rate monitoring feature of the Mi 11 for the first time, which can read your heart rate as accurately as smart band/watch does.”
— Goodix (@GoodixTech) December 28, 2020
The optical under-display fingerprint scanner literally takes a photo of your finger. The heart rate measurement uses a technique known as photoplethysmography (PPG). As exciting as the feature is, however, it’s worth noting that the technology has been criticized for being inaccurate. In a paper published in Nature, there are three areas where PPG is said to fall short: diverse skin types, motion artifacts, and signal crossover.
The use of PPG could have been implemented in smartphones before with optical under-display fingerprint scanners, but it was just a matter of figuring out how to take the images of your finger from the scanner and determining the heart rate based on changes in the image. Many wearables, including the Apple Watch, use PPG.
Xiaomi added heart rate monitoring support using the camera and LED flash to its Mi Health app back in September, so a feature like this makes sense for a more integrated experience. While PPG isn’t the most accurate way to measure your heart rate, it’s a convenient way to get an idea of your heart rate when you don’t have access to professional medical equipment.
If you’re not interested in the Mi 11’s fingerprint sensor/heart rate monitor, the device still has plenty to offer. It features a gorgeous design, triple-camera setup, and it’s the first device to launch with the new Qualcomm Snapdragon 888 processor.
The Xiaomi Mi 11 will be available to pre-order in China for CNY 3,999 ($612) for the 8GB + 128GB variant, CNY 4,299 ($657) for the 8GB + 256GB variant, and CNY 4,699 ($719) for the 12GB + 256GB variant. Pre-orders begin today in China, with open sales from January 1, 2021.