Most of these doctors (99.999%) personally endorsing hyperbaric chamber brands are paid off somehow; either a free unit for them to have with a nice little check for their "input" on why their hyperbaric oxygen chamber is so good. THESE DOCTORS ARE JUST COMPANY MASCOTS FOR THAT EFFECT! If you really look into the medical industry's reputation of who these doctors are, they are nobodies with huge egos from "telling people what to do" just because they are "doctors". Don't be tricked into thinking that these doctors actually mentioned the brand because they were on a search like you for the best hyperbaric oxygen chamber. But if they did, you'd never know about it through the company's websites whoring them out to seem "therapeutic-grade". By the way, a "doctor's endorsement" doesn't mean that the particular hyperbaric treatment chambers are made with medical research. Don't become the sucker.