The Full Stack of a Health Wearable: Silicon to Software

It’s the golden episode (season 3, episode 3), and Eden and Ellen are getting a little science-y. This one’s all about health tech wearables — the rings, watches, and bands tracking your every move, and what’s really happening under the hood. We break down: How the hardware senses your body — optical PPG (photoplethysmography), ECG, LED light, and why the fingertip and earlobe are prime real estate for readings The metrics — heart rate, HRV, respiratory rate, blood oxygen, blood pressure, temperature, and how each one is actually derived Signal vs. noise — why your ring is more trustworthy asleep than mid-workout, and the adaptive filtering that cancels out your footsteps AI, machine learning & inference — the difference between measured data and educated guesses, and why you are your own baseline (and why that baseline is the real product lock-in) The competitors — Oura, Whoop, Garmin, Apple, and up-and-comers like the Lumia ear cuff Your data & who’s protecting it — privacy policies, consent screens, Washington’s My Health My Data Act, Senator Cassidy’s proposed HIPRA, and what happens to your data when a company changes hands As always — we’re no doctors, lawyers, or geopolitical specialists. Stay safe out there.