Endoscopic bite block

A detachably connectable bite block assembly comprising:

• (a) an oral-nasal cannula configured to collect exhaled breath for capnographic monitoring and to deliver oxygen, said oral-nasal cannula comprising:
• an oxygen delivery bore in fluid connection with at least one delivery opening and an oxygen supply tube, and
• an exhaled breath collection bore in fluid connection with an oral prong, at least one nasal prong and a breath collection tube;
• and
• (b) a bite block comprising:
• a hollow tubular portion configured for insertion into a subject's mouth, said hollow tubular portion configured to engage, on an outer portion thereof, said oxygen supply tube and thereby to detachably connect said bite block with said oral-nasal cannula, such that when said oxygen supply tube is engaged on said hollow tubular portion a valve is configured to open, and when said oxygen supply tube is disassembled from said hollow tubular portion the valve is configured to close;
• and
• a main body portion from which said hollow tubular portion extends, said main body portion comprising a longitudinal groove configured to detachably accommodate said oral prong of said oral-nasal cannula, such that oral breath exhaled through said hollow tubular portion is directed towards said groove for collection by said oral prong.