What types of devices are used in hospitals, based on pressure, for inhalation therapy to save lives?

barometric chamber doesn't have a letter next to it. Anyway, did you even stop to think about this? five minutes on wikipedia could have given you the answer. baro means pressure. Those are used in decompression sickness, air emboli, and CO poisoning. A and B are both diagnostic tools and have no therapeutic uses and nothing to do with pressure. Iron lungs aren't used anymore, otherwise that would be correct. Respirators are also therapeutic, used in hospitals, and based on pressure.