Oxygen concentrators (oxygen generators) are a type of medical device that you may use as part of oxygen therapy. If you have a condition that affects your lungs or even if you have some difficulty breathing, an oxygen concentrator helps get your body the oxygen it needs to function.
Unlike a compressed or liquid oxygen tank that you must replace or refill when you run out of oxygen, an oxygen concentrator continuously purifies the air around you (atmospheric air) to deliver 90% to 95% pure oxygen. You breathe in the oxygen through a plastic mask that fits over your mouth and nose or a flexible plastic tube with two prongs that go into your nostrils (nasal cannula).