I am not really involved with these tests: I believe they are not the same people every time, because doctors tend to be quite busy, and don't have much free ti

I am not really involved with these tests: I believe they are not the same people every time, because doctors tend to be quite busy, and don't have much free time available. They are coming at least from different continents, but obviously to answer the sibling's comment they are selected by the company, from a pool of advanced users or early adopters, so not necessarily a good reflection of the whole population of final users. And this is an issue in itself because the product is influenced by expert users, but at least, you cannot release a totally horrible or misleading UI that no user has ever seen before. The other side effect, intended or not, is that you cannot change the UI at every iteration of the product because these tests tends to be costly, as a result, the evolution of the design is quite conservative, which might also explain in part why medical devices UI tends to look "outdated".