[deathflute]

I would scale down your medical operation bit by bit while spending more time building the skills necessary to launch your start up. Only once you are confident enough of pulling it off, would I work full time on it. Basically, not only you have the risk of your start up being a complete failure but also that you might not be able to pull it off technically. The latter risk can be completely hedged away by my first piece of advice.

[staunch]

Yes. Once you've built a few web apps and are confident you can build the one you want to be for your startup you're ready. At that time you should definitely go full-time if you want to maximize your chances of success.

Just don't go full-time until you're not going to be spending the first 6 months learning.