For comparison, to maintain a >94% blood oxygenation for my medical needs (staying conscious and alive!) at 607' ASL, I breathe 1.5 liters/min. of 95% pure oxygen. The gas is supplied by a concentrator which utilizes a zeolite molecular sieve. I used to need 4 l/m, but when I was hospitalized for a cardiac arrhythmia two years ago, I was treated with BiPAP: BiLevel Positive Airway Pressure. This therapy opened some of the cigarette-clogged alveoli in my poor old lungs, resulting in a much improved oxygen requirement. Lord knows I rue the day I took up smoking. It took forty-eight years for me to put those "health tubes" down. The Grim Reaper was in the room and he was walking directly toward me! Rapidly!
- Ed