I made a video with the amazing Steve Mould! Have you ever wondered how your Apple Watch/Fitbit/Garmin/etc can measure your heart rate from your wrist? Turns out the key is the little green flashing light…and I popped round to Steve’s, strapped him up with electrodes, and used the same principle to extract his heart rate from a video of his face!
We also look inside our hands using infrared light to explain how smartwatches (and those little finger-mounted pulse oximeters) can use more flickering lights—red and infrared this time—to work out how much oxygen there is in your blood.
And then, as a follow-up, I tested three popular brands of wearable—Apple, Fitbit and a bargain-basement £30 Mi Band—to see if the numbers they provide for heart rate, steps and sleep are actually accurate. These devices make a lot of claims about their health-tracking features…so how do they stack up?
These are the first two episodes in a series on smartwatches, so if there’s anything you’d particularly like investigating let me know! The next video will be about what you can actually do with the numbers that these devices spit out, and I’ve also got videos planned on calorie counts (accuracy and perils thereof), and the issues with heart rate sensors for Black people.
So check out the first two videos in the series on YouTube, and let me know if there’s anything in particular you’d like me to investigate!