Alan
To do something comprehensive you'll need to write both clinical & technical specifications. For the former put the onus on the clinical users to state explicitly the range of procedures they want to undertake using the scope together with specific imaging & manipulation requirements. If they are using it in conjunction with other equipment e.g. laser then the required interfaces should be listed. Then comes the displays. For all but the simplest requirements you're talking HD plus associated image capture, record and archive facilities & possible interfacing with hospital network. On the technical side apart from the usual general requirements the digital imaging requirements need to be detailed particularly if is to be interfaced & networked & a statement extracted from potential bidders on their commitment to software updates & virus prevention.
I have some old specs on microscopes themselves which I will send you.
Cheers
