An oxygen concentrator is a medical device that concentrates oxygen from ambient air for delivery to patients who require supplemental oxygen therapy. Unlike compressed-oxygen cylinders, which store a finite supply, a concentrator produces oxygen continuously from room air for as long as it is supplied with electrical power.
Most modern concentrators use pressure swing adsorption (PSA) technology, in which compressed air is passed over a zeolite molecular sieve that adsorbs nitrogen, leaving oxygen-enriched gas that is typically 90 to 95 per cent pure.
History[edit | edit source]
The use of oxygen therapy was first reported in 1885, when the American physician George E. Holtzapple used oxygen to treat pneumonia. Oxygen concentrators for home use were developed in the late 1970s. The 1980s and 1990s brought rapid improvements: devices became smaller, quieter and more energy efficient. Portable oxygen concentrators were approved for use in the early 2000s.
Principle of operation[edit | edit source]
Ambient air contains about 78 per cent nitrogen, 21 per cent oxygen and 1 per cent other gases. An oxygen concentrator separates the nitrogen from the air using pressure swing adsorption. Compressed air passes into sieve beds filled with zeolite, which at high pressure preferentially adsorbs nitrogen molecules while allowing oxygen to pass through. The oxygen-enriched gas, typically 90 to 95 per cent pure, is collected and delivered to the patient.
Types[edit | edit source]
Stationary concentrators[edit | edit source]
Stationary (home) concentrators are designed for continuous use at a fixed location. They typically deliver continuous-flow oxygen at rates from 0.5 to 10 litres per minute.
Portable oxygen concentrators[edit | edit source]
Portable oxygen concentrators are battery-powered units that allow patients to move about and travel while receiving oxygen therapy. Many models are approved for use aboard commercial aircraft.
Medical uses[edit | edit source]
Oxygen concentrators are used to treat conditions that cause low blood oxygen levels, including COPD, pulmonary fibrosis, pneumonia, and respiratory distress caused by COVID-19.