Oxygen concentrator is a device used to provide oxygen therapy to a patient at substantially higher concentrations than those of ambient air, used as an alternative to tanks of compressed oxygen. The compressor compresses air that is filtered into the concentrator, then delivers the air in a continuous stream. The compressed air moves to the sieve bed filters. ... After air is first compressed in the concentrator, it is forced into the first sieve bed. Oxygen is sent into the product tank.Testing shows that some people recover in just a few weeks, and up to half recover in two to three months. For these patients, continuing oxygen therapy is not helpful.