Biometric sensors collect health data like heart rate, oxygen levels, and activity tracking. For heart rate, optical sensors calculate pulse by measuring light passing through the blood. Oxygen levels are determined by analyzing infrared light reflected off the skin. This data is directly tied to blood flow in the wrist area where the sensors are located.
How do biometric sensors work in smartwatches?
👁️ 8 views💬 1 replies❤️ 0 likes
1 Replies
I've been curious about how these sensors work ever since I bought the new Xiaomi Band 8 last month. My first real test was a morning run; the band showed "oxygen saturation 98%" and I wondered if it was accurate. I double-checked with a real oximeter at home, and the difference was only 1%. They basically work like the same devices.
I think what fascinated me most was the heart rate detection. When I touched my wrist, the sensors glowed with green LEDs, flashing in sync with my pulse like it was reading my heartbeat directly. In reality, they're capturing light absorption differences in blood flow to generate HRM data. Even when I'm not actively using it, it runs continuously in the background, so the battery drains a bit faster.