Oral/nasal cannula manifold

An oral/nasal manifold for collection of exhaled nasal and oral gases respired by a patient, comprising:

• two nasal prongs for insertion into nostrils of the patient;
• a collection tube for the collection of exhaled gases from the patient, one end of said tube connected to one of said nasal prongs;
• and
• an oral conduit prong for placement near an oral cavity of the patient for the collection of orally exhaled gases from the patient, the conduit passage of said one nasal prong passage and said oral conduit passage being straight, and the straight passage of said oral conduit connected to and aligned in the same plane as the straight passage of said one of said nasal prongs, whereby the aligned conduit passages are connected with the conduit passage of said collection tube without any adjacent connected void volumes in any of said cannula passages, and the pressures of the exhaled nasal and oral gases of the patient directly oppose each other in said straight aligned passages to provide an optimal sampling of the patient's exhaled gases for analysis.

A method of collecting exhaled gases from a patient, the method comprising:

• providing an oral/nasal manifold having two nasal prongs for insertion into the nostrils of the patient with one end of a collection tube for collecting exhaled gases from the patient connected to the conduit passage of one of the nasal cannula prongs, and an oral prong with a distal port for placement near the oral cavity of the patient and having a straight conduit passage connected with a straight conduit passage of said one of the nasal prongs;
• connecting the straight conduit passage of said oral prong to said straight conduit passage of said one nasal prong in alignment in the same plane and thereby providing a connection to the conduit passage of said collection tube without the inclusion of any ancillary void volumes in any of said conduit passages;
• inserting said nasal prongs into the nostrils of the patient;
• placing said oral distal port near the oral cavity of the patient;
• attaching said collection tube to a gas analyzer;
• and
• applying a vacuum force at said gas analyzer, such that the exhaled gases flowing through the connected manifold conduit passages move from said collection tube to said gas analyzer and the pressures of the exhaled nasal and oral gases of the patient directly oppose each other in said straight aligned conduit passages to provide an optimal sampling of the patient's exhaled gases for analysis.