How does a portable oxygen concentrator work?

Portable oxygen concentrators are medical devices that help people with chronic lung conditions increase the oxygen level in their blood. Unlike the oxygen tanks and liquid oxygen systems that require replacement and refills, portable oxygen concentrators purify the oxygen from the air we breathe:

1. The concentrator draws in the air from the environment. The air that goes into the concentrator consists of about 20 percent oxygen, 78 percent nitrogen and 2 percent other gases.
2. The air is pulled into the cartridges filled with the material called Zeolite. Zeolite captures nitrogen through a process called pressure swing adsorption, thus concentrating the oxygen.
3. The concentrated oxygen is delivered to the patient via a nasal cannula.
4. Part of the oxygen is fed back through the cartridges to help clear out nitrogen and other gases that are then expelled back into the atmosphere.
5. The above process repeats.