This is HBO?

At sea level atmospheric pressure is about 15 pounds per square inch, or 100 kPa (kilopascals), or 760 mm Hg (millimeters of mercury) or 30 inches of mercury, or 15 psi (pounds per square inch) or 1 bar. Please note For simplicity I have rounded widely. At this pressure the air we breathe is about 20% oxygen. With hyperbaric oxygen (HBO) to a patient is placed in a pressure chamber usually filled with oxygen 100%. The pressure is increased to two atmospheres, or twice the normal atmospheric pressure. This increased pressure causes the oxygen in the tissues and plasma, and the body is less dependent on the oxygen dissociation curve of hemoglobin and blood circulation. Hyperbaric therapy has been used with divers and water workers drawer deep suffering of the curve. HBO is used to treat carbon monoxide poisoning, victims of gas gangrene, tetanus (I'm not sure about that) and more recently of a stroke. It is being studied for treating spinal cord injuries and cerebral palsy.

Traumatic Brain Injury Hyperbaric Oxygen Therapy