Video demonstrating how and why those red and green LEDs measure heart rate and SpO2, and why they need to flash

Image of smartwatch above a hand, with violet light shining down on the hand, which reveals the veins

Smartwatches use a flashing green light to measure your heart rate and a red and infra-red light to measure your oxygen saturation. The way it works is really clever, and this video demonstrates that.

See https://youtu.be/BFZxlauizx0

#technology #health #smartwatches #heartrate #SpO2