What does the term "test of choice" means in the U.S. healthcare system? 
What does an approval as a "test of choice" for a medical device means?
How many devices\procedures were approved as a "test of choice" in the
past three, five, and ten years?
How long does the whole process takes from application to first orders
of such device from clinics and hospitals?

You are likely to get better results by posting each of these items as
a separate question. When multiple questions are bundled together,
some Researchers may be leery of taking on a project, since a failure
to be able to answer any part of the package will mean that no
compensation can be received by the Researcher.

thanks, I'll do so