The user manual for non-medical chamber recommends users to have a medical check-up before using the chamber. Anyone with average studies can operate the chamber as long as reads the user manual. The user manual for medical chamber states that the chamber can be used only with medical consent from a doctor and it requires medical assistance during the treatment.
So a doctor or hyperbaric technician has to be around when operating the chamber. This chamber will be certified as Class IIB medical device according to EEC 93/42. You have to check what regulations in your country say about using a Class IIB medical device.
That is the reason why small practices and private people prefer nonmedical status, while medical facilities want the medical version. In Japan this kind of chambers had been used for 20 years now mostly as nonmedical devices.