In putting together the article above, Christina Farr was gracious enough to listen to my theory about Apple’s not-so-secret plan that explains why there’s suddenly an ECG in the Apple Watch 4. What surprised me the most is that everyone focused on it as an ECG, including all of the tech and digital health press, and missed Apple’s brilliant, extremely broad patent from 2014.
If you go looking, the name for what Apple patented (again, brilliantly) is a way of measuring something called pulse transit time (PTT) from wrist-worn devices alone. PTT is a proxy for cardiovascular health, in the same way measuring blood pressure with a cuff is a proxy for cardiovascular health. What you’ll find is that as of a little more than a decade ago, pulse transit time in laboratory settings was considered unreliable as a proxy for a blood pressure cuff. But then… that wasn’t being done by Apple.
Continue reading “Hardware, software, data, and how Apple’s control of all three defines the future of digital health”