Patent ID: 7841988

Claim:
A nasal mask, adapted to be attached to a face of a subject so as to cover a nose of the subject, comprising: a shell, having a contact edge adapted to be brought into close contact with the face of the subject, thereby forming a sealed space therein; an attachment portion, disposed in the shell and having an inner space, the attachment portion being configured to detachably engage with a sensor disposed outside the shell and operable to measure concentration of carbon dioxide gas expired from the nostrils; and a guide member, disposed inside the shell and forming a passage adapted to introduce expired gas from nostrils into the inner space, wherein: the shell is formed with an inlet adapted to introduce external gas into the sealed space; the expired gas is guarded by the guide member from the external gas introduced through the inlet; and the attachment portion is formed with an outlet adapted to discharge the expired gas from the inner space to the sealed space.