I'm not an expert on medical positioning, but I've often admired the clean and crisp look of Stefan Hattenbach's Stalemate, available from Fountain. According to the website, Stalemate "was originally constructed as a proprietary font for a German IT-company." Moreover, it "was designed to work both in print and on screen and experience shows that it performs well in both environments." It could be just what you're looking for.

Here's a link to a PDF sample as well. Good luck!

Hi Diane,

First off, I'm not quite a professional yet, I'm a student, so my suggestions may not be 100%, but here they are anyways :) If you're going to be using a sans for the body copy, I'd recommend a serif font, or a sans with some character for the display type. Here's just a few of my suggestions…

Democratica if a quirky font that is modern/hi-tech, and I don't know it seems kinda 'medical' to me
http://www.myfonts.com/fonts/emigre/democratica/

Modern 735 is more conservative, but certainly is professional, and modern.
http://www.myfonts.com/fonts/bitstream/modern-735/

Kingsbury Conensed is interesting.
http://www.myfonts.com/fonts/spiecegraphics/kingsbury-condensed-sg/

Ultra Bronzo is a sans, but has a good deal of character, fairly clean and high tech.
http://www.myfonts.com/fonts/thirstype/ultra-bronzo/

Ditto with Copperplate Modern…
http://www.myfonts.com/fonts/wiescherdesign/copperplate-modern/