Oxygen concentrators filter surrounding air, compressing it to the required density and then delivering purified medical grade oxygen into a pulse-dose delivery system or continuous stream system to the patient.
It’s also equipped with special filters and sieve beds which help remove Nitrogen from the air to ensure delivery of completely purified oxygen to the patient. These devices also come with an electronic user interface so you can adjust the levels of oxygen concentration and delivery settings. You then inhale the oxygen through the nasal cannula or special mask.
You generally measure the oxygen concentrator output in LPM (liters per minute). Your doctor will determine what level of oxygen you need, which may vary at rest, during sleep, and when you exercise.