Now that you (almost) have paying customers you need to prove that you can deliver the right quality at the right price. Figure out how exactly you will deliver your value proposition. Start with the aspects of your solution that are most critical for quality and price.
In a concierge test you deliver the value proposition as a personal service in order to gain first-hand experience with real customers. Only at a later stage you will automate these tasks for scaling.
As the Wizard of Oz you perform tasks manually that will later be automated. In contrast to the Conierge test (see above), customers do not necessarily notice this.
This article sheds light on the lengthy process med-tech start-ups go through before they can launch their product and presents ideas on how the ecosystem could better support start-up founders.
There are some important things to consider when entering a regulated market. In this article by Steve Blank, you will learn the most important points and find other helpful sources of information.