Another not quite direct answer, but at least in my part of the world these kind of companies are more often "spin-outs" from university research departments an

Another not quite direct answer, but at least in my part of the world these kind of companies are more often "spin-outs" from university research departments and institutes rather than "start-ups" from the general economy. It might be worth having a look the universities doing research in this area, then seeing if any of them have a group in a business incubator.