[Firecracker]

My friend and I hacked on something like this for a while, and eventually got something pretty accurate for measuring heart rate. Shipped on iOS as [0].

It did indeed require a lot of additional tweaks and benchmarking. Honestly don't think any part of our original algorithm or the tricks in the paper made it into the final version. Just doing a Fourier type thing works rarely (~20%), but the principle does work; you can get it working ~90% of the time. That said, I'd be surprised irregular heartbeat were doable in a short recording period. But I'd love to be surprised!

[0] Hands Free Heart Rate Monitor (free, private) https://apps.apple.com/app/id1457939511