Does anyone have links or advice that would be helpful?
Like I don't know if I should try to sell the idea, build a company for it, or what. I think the best thing to do might be to partner with or sell the idea to an existing company that prices things reasonably (for patient benefit) and is already established in the medical device market (has experience with testing, approval, and marketing).
Your options are to try to patent it or/and try to build and market it. Neither is guaranteed.
However, nobody is going to want to give you money just for an idea. You need something to sell, either a patent or an established business.