defensive publishing for medical ideas?

[Joern Rennecke]

I've got an idea for a mediacal procedure.  It's one of those things that
are obvious once you put all the pieces together, put with a huge potential.
I think it would be immoral to put a premium on its use, so it shoudn't be
patented.  But undoubtedly some will try to.
Where is the best place for defensive publication of such ideas?