While I’m sure the obvious systemic issues contribute to not looking for alternatives, that does sound like largely an issue inherent to optical pulse oximeters. Engineers aren’t miracle workers, they can’t change physics to their liking.

I’m sure pulse oximeters now are more accurate than they were 20 years ago. The fact we’re still using them is because no alternatives have been found which are as easy to use, reliable, and non-invasive as pulse oximeters, even with the known downsides.

Repository: a collection of computer code for a software program (or app if you insist).

Fork: a copy of a repository so you can edit it without affecting the original.

Pull request: a request to the owner of a repo to bring in some changes you made in a fork.

I think I even got the word count down.