Patent ID: 7445602

Claim:
An airway adapter of a sensor for detecting a carbon dioxide gas in an expiration gas of a living body, the airway adapter comprising: an airway case, adapted to be disposed below nostrils of the living body, and formed with an airway passage extending across an optical axis of a light beam emitted from a light emitter of the sensor, the airway case having a front side and a back side that opposes the front side, the back side positioned adjacent a face of the living body when the airway case is positioned on the face of the living body; an oxygen supply tube; and a retainer that retains the oxygen supply tube on the front side of the airway case such that an exit of the oxygen supply tube is adjacent a side of the airway case other than the back side of the airway case, when the back side of the airway case is adjacent the face of the living body, whereby an oxygen gas supplied from the exit of the oxygen supply tube is not directly injected into the nostrils.