Patent ID: 7954490

Claim:
A method of providing concentrated oxygen product gas to a patient, the method comprising: producing product gas with an ambulatory oxygen separator using a vacuum swing adsorption process that includes: (a) introducing ambient air into a first end of a column containing an adsorbent material that preferentially adsorbs nitrogen and removes oxygen-rich product gas out a second end of the column; (b) evacuating the column through the first end to remove adsorbed gas from the column; (c) repressurizing the column by introducing product gas into the second end of the column and ambient air into the first end of the column, wherein introducing product gas occurs during an initial portion of the repressurization; (d) repeating steps (a)-(c); pumping the product gas from the separator to a storage reservoir; storing product gas produced by the vacuum swing absorption process in the reservoir of the ambulatory oxygen separator at a pressure of about 1.0 atm to 2.0 atm; delivering a fluid to the patient consisting essentially of the product gas through a dispensing valve that regulates the amount of product gas delivered from the reservoir to the patient; and controlling a cycle rate at which steps (a)-(c) are performed as a function of product gas delivered from the reservoir.