Honestly I think your chances are slim to none for HBS and Stanford unless you have some exceptional non-academic/non-scientific accomplishments to complement your profile.
As for Wharton, you may have an outside shot, but it comes down to how well you execute your application and whether you can show yourself to be more than a "lab rat" (i.e. you have strong interpersonal/leadership skills).
Columbia and Sloan will be stretches - unless if you'll regret not applying to one of H/S/W, you should focus on schools in this tier as your stretches (Columbia, Sloan, Kellogg, Chicago, and Tuck -- all of which are more or less equally hard to get in). Maybe choose 1-2 schools from this list.
Schools where you may be more competitive for are places like Duke, Michigan, Darden, Haas, UCLA, NYU, Cornell and Yale. Choose 3-4 from this group.
Beyond that, given your age and career path you really should focus on part-time or executive programs if you're planning on staying in healthcare, since you're not making a career switch as much as a switch in job function within the same industry (from technical to managerial). And money-wise it may be more worthwhile for you since you'll be working and studying at the same time with no lost income (not to mention that you'll be studying alongside students that are closer to your age than in full-time programs where most of the students are in their mid- to late-20s).
Alex Chu
alex@mbaapply.com
www.mbaapply.com
http://mbaapply.blogspot.com