Portable oxygen concentrator

A portable oxygen concentrator, comprising:

• a plurality of sieve beds including first and second sieve beds;
• a compressor for delivering air to the sieve beds;
• a set of control valves between the compressor and the sieve beds;
• at least one reservoir communicating with the sieve beds for storing oxygen exiting from the sieve beds;
• a delivery valve communicating with the at least one reservoir;
• one or more pressure sensors for measuring reservoir pressure within the at least one reservoir and for measuring a pressure drop across the delivery valve;
• and
• a controller coupled to the control valves for selectively opening and closing the valves to alternately charge and purge the first and second sieve beds, the controller further coupled to the pressure sensors for monitoring the reservoir pressure and the pressure drop across the delivery valve, the controller further coupled to the delivery valve for selectively opening the delivery valve for predetermined pulse durations to deliver pulses of gas from the at least one reservoir to a user, the controller configured for adjusting the pulse durations based at least partially upon the reservoir pressure and the pressure drop across the delivery valve.

A method for concentrating oxygen using a portable apparatus comprising first and second sieve beds, each including first and second ends, and a reservoir communicating with the second ends of the sieve beds, the method comprising:

• cyclically charging a first sieve bed while purging a second sieve bed and charging the second sieve bed while purging the first sieve bed for charge/purge durations, whereby oxygen passes from the first and second sieve beds during charging into the reservoir;
• monitoring pressure within the reservoir;
• and
• adjusting the charge/purge durations based at least partially upon the pressure within the reservoir.