Patent ID: 7329304

Claim:
A portable oxygen concentrator, comprising: a plurality of sieve beds adapted to absorb nitrogen from air, including a first sieve bed and a second sieve bed, each sieve bed in the plurality of sieve beds comprising an air inlet/outlet end and an oxygen inlet/outlet end; a reservoir communicating with the oxygen inlet/outlet ends of the plurality of sieve beds and adapted to store oxygen from the plurality of sieve beds; a compressor adapted to deliver air at one or more desired pressures to the air inlet/outlet ends of the plurality of sieve beds; a set of valves disposed between the compressor and the air inlet/outlet ends of the plurality of sieve beds; a pressure sensor adapted to measure a reservoir pressure within the reservoir; an oxygen sensor adapted to measure an oxygen purity within the reservoir before delivery to a user; and a controller coupled to the valves and adapted to selectively open and close the valves to alternately charge the first sieve bed while purging the second sieve bed, and charge the second sieve bed while purging the first sieve bed, wherein the controller is coupled to the pressure sensor and is adapted to monitor the reservoir pressure, wherein the controller adjusts a charge/purge duration that the first and the second sieve beds are alternately purged at least partially based upon the reservoir pressure, and wherein the controller is coupled to the oxygen sensor and adapted to adjust the charge/purge duration at least partially based upon the oxygen purity.