Hyperbaric Oxygen Therapy
Hyperbaric oxygen therapy (HBOT) is a medical treatment in which the patient is entirely enclosed in a pressure chamber breathing 100% oxygen at greater than normal atmospheric pressure.
Hyperbaric therapy was originally used to recompress deep sea divers once they got to the surface to avoid geting the 'bends'. By decompressing divers slowly in a vessel at the surface they could avoid gas bubbles from forming in their bodies, which could cause 'stroke-like' symptoms.