Patent ID: 8752548

Claim:
A patient ventilation system comprising: a breathing circuit comprising an inspiratory channel and an expiratory channel adapted for connection to a patient; a gas mixing arrangement connected to said inspiratory channel to deliver a gas mixture comprising oxygen and a second gas to said patient via said inspiratory channel, said gas mixing arrangement being configured to regulate an amount of said second gas in said gas mixture; at least two gas inlets connected to said gas mixing arrangement, said second gas being supplied to said gas mixing arrangement via one of said gas inlets; a gas identification unit configured to detect an identity of said second gas by actively measuring a value of an identity-indicating characteristic of said second gas; a flow meter through which said second gas flows; and a correction unit connected to said gas identification unit that generates a correction value dependent on the detected identity of said second gas by said gas identification unit, said correction unit supplying said correction value to said flow meter to calibrate said flow meter to accurately detect flow of said second gas having the detected identity.