This is exactly the value proposition of my startup, TouchFree Labs. We're developing software that uses the Leap Motion Controller to allow surgeons to manipulate medical images inside of the operating room. You can see a demonstration of an early prototype here: http://www.youtube.com/watch?v=WaO-cimDOEQ. Demo starts at about 35s. (Apologies in advance for the low production value.)
Right now our bottleneck is medical expertise, and we're looking for surgeons who would be interested in collaborating with us. We're developing workflows that are tailored for different types of procedures, which requires very specialized knowledge. The application also learns the nuances of individual users' movements to improve gesture recognition, which requires lots of data.
I don't know how far away you are from Toronto, but if you could pass the message along to your dad, I'd be very grateful--if only to get some basic feedback. But if he's interested, he could be among the first surgeons in the world to use the Leap Motion inside of an operating room.