alt Hacker NewsAll of these problems are solved by buying a CA$35 Colmi ring off Aliexpress.
1. If your finger changes size, spend another $35 for a second one.
2. If it gets scratched to shit, buy another one. Though I lift with my plastic R09 and there's only a bit of scratching around the edge. Other models are metal and should resist scratching better.
3. If it eventually breaks, get another one. Personally I fidget with mine a lot, so removing it before or after washing my hands happens unconsciously.
On top of that, the protocol has been reverse engineered so you can use Gadgetbridge or make your own app instead of using the stock one.
No idea how it compares, but my local Lidl was selling a smart ring for $15 so I decided to give it a shot. I assume half the measurements are "for entertainment purposes only" (glucose, blood pressure, stress [heart rate variability proxy?], blood oxygenation [might be ok with my skin tone, not sure I'd trust it]) but the others seem fairly accurate. Again, no idea how it compares to the pricier ones, but seems to match my pulse measured at neck and what I remember of my nightly sleep pretty well.
And yeah, I'm certainly not going to worry about it getting scratched or slightly wet. Actually, it got dropped and stepped on, and is slightly dented but still seems to run fine - the epoxy sealant for the electronics seems intact and while I was a bit concerned for the battery, that's been a while with no issues.
And, while I have no idea whether the app is quietly collecting data and pushing it to a server in china (if it is, it is doing it in a way that is sneaking past the firewall), at least it does not require creating an account to use.
So in that sense it is maybe more private than oura or samsung ?