how to create an electrocardiogram observation?

[Andresfyc]

[p2-apple]

This question goes beyond just how to use this library. An answer depends a lot on what exact data you have and what you want to do with it, e.g. storing it in an EHR vs. submitting it somewhere else.

The first step is figuring out if there is a profile that covers your use case, which varies by jurisdiction and other factors. My best advice is to head over to chat.fhir.org and ask there.