We’ve found the Oura Ring to be the closest thing to a medical wearable which is convenient and really hard to break.
For those interested in how the Oura Ring works, Jerrie who worked on the Omic prototype has sent through an interesting clip where the Oura is fully dismantled.
https://www.ifixit.com/Teardown/Oura+Ring+2+Teardown/135207
Enjoy!