I am not a "nurse inventor", but I share your concerns about having my idea stolen and someone else taking the credit (and $$$), from MY idea or invention.
This is called a "back door" copyright".
Type up you idea (or story, writing), in as much detail as you can.
Then put it in an envelope and mail it back to yourself, and when you get it back in the mail, (this is the most important!), leave the letter UNOPENED!. It now has a legal date stamp courtesy of the Post Office. Put it in a safe place.
You then have legal proof that it WAS your idea, (or Intellectual Property), and can prove it.
You might want to contact an attorney who specializes in copyrights, and get some legal advice. In the meantime, the letter should prove your ownership in the short term. Hope that helps.
Lindarn, RN, BSN, CCRN