It would not be possible to do this... A healthcare org has to refer to the patient records long after your visit is over. In a hospital, there is generally reporting that takes place which requires extensive reviews and audits of the care given, and alot of these audits can take place nearly half a year after you were seen. There is also the fact that after your visit, the record will be reviewed for medical coding, which is how you, your insurance, and or the gov't are billed for the care that you were given. The idea that when you leave, your record is locked, is just not realisitic. I can also say that the latest push by the federal government, with these EHR incentives, is pretty much going to do the opposite of what you are asking for.
I have seen medical practices on both ends of the security fence, and it is sad... I've been in practices that I would never, ever, visit as a patient because I have no faith in how things are run there from an IT security view point... At the same time, I have worked with other orginazations that do take security very seriously, and do everything possible to ensure that all data is kept private... The thing that really sucks is that you really have no way of knowing what type of office you are visiting until you see the report that your record has been leaked.
Someone else posted in here that most practices are afraid of HIPAA and will do anything to keep things safe... Unfortionately I have seen alot of practices that couldnt give a crap about HIPAA and won't listen to any reasons as to why they should not run bittorrent on their office computer. The bottom line is that until HIPAA and HITECH start producing more results, busting more practices, and making everyone aware that they do have teeth this is going to continue to be a problem. HIPAA has been around for a long time, but until HITECH came around it has been a joke, and only enforced in the worst of senarios. I still think that both of the policies are too loose, and enforcement on those policies today is still largely reactive, when it's too late.