I think that stone has been turned quite awhile from now. It wouldn't make much sense to spend the money on patents especially the US one if all that wasn't reviewed by their attorneys. At the very least with Zoutman's and Shannon's backgrounds, they would know the regulations on ozone in hospital settings.
I think it been written in different ways on this board that they have created a machine that can probably be considered idiot proof as far as medical equipment. I believe training is part of the price?