Assuming you want to do entrepreneurship in the future, I think your question is too general.
What is the scope of "ideas or startups" are you thinking of? The next generation of da Vinci surgery? Virtual reality programs where you can teach medical students how to do surgery in 3D hyper-interactive holograms? Or do you want to make mammograms, X-ray and CT scans cheaper, safer in the long run, and more efficient? What are your interests? Or you just want to pursue whatever is in need?
Are you trying to think of ways to invent brand-new, ground-breaking entities that we have never seen before? Or are you thinking of ways to make existing softwares and devices cheaper, so that they can be applicable in rural areas, even developing countries?
It will be also helpful to know what type of audience to whom you are trying to sell. Is it for medical schools? Large hospitals? Rural hospitals? Small clinics? Nurses? PAs? Surgeons?
What are your objectives? Do you just want for-profit companies later on? Do you just want patents and published papers? Or do you want to target specific problems that are personal to you?
I am asking these questions, because we can talk about problems all day long; however, sometimes depending on how you define problems, even if they look the same at first, solutions might not be all about creating startups and etc, but maybe simply making a cheat sheet where you can remind yourself key questions or information that you tend to forget as a doctor.
For example, if you are interested in reducing some medical errors, I would start with this to show you what I meant:
http://www.hulu.com/watch/122111
Start from 23:23 if you are busy.
