Airway adapter

Claim 1

An airway adapter for obtaining a sample gas flow from a patient's exhalations, comprising: a tubular body having a cylindrical wall containing an annular channel, said cylindrical wall and annular channel surrounding a hollow interior for passing a gas flow therethrough, the thickness of at least a portion of the wall of said adapter gradually increasing along the direction of gas flow from one end of said tubular body to said annular channel to form a first conical interior surface, the thickness of at least a portion of the wall of said adapter gradually decreasing along the direction of gas flow from said annular channel to the other end of said tubular body to form a protruding region of said wall in said hollow interior in the region of said annular channel; a port in said wall providing fluid communication between said annular channel and ambient atmosphere; and a plurality of radial channels extending between the interior of said tubular body and said annular channel to provide fluid communication therebetween, said radial channels forming a plurality of parallel slits through said protruding region, said slits being substantially parallel to the longitudinal axis of said adapter.

Claim 6

A method of forming an adapter for obtaining a sample gas flow from a patient's exhalations, the sample gas flow being obtained by a sampling air tube, the method comprising the steps of: forming two annular members having cylindrical walls and a hollow interior and opposing faces adapted for mating engagement; forming an annular groove in each of said opposing faces; forming a plurality of radial slots in each of said opposing faces which extend from the hollow interior to said annular groove; forming a cut out in each of said faces which extends from said annular groove to the periphery of said cylindrical wall; and joining said opposing faces together in such a way that said annular grooves form an annular channel, said radial slots form a plurality of radial channels and said cut outs form a port providing fluid communications between said annular groove and said sampling air tube.

Claim 7

A method of forming an adapter for obtaining a sample gas flow from a patient's exhalations, the sample gas flow being obtained by a sampling air tube, the method comprising the steps of: forming two annular members having cylindrical walls and a hollow interior and opposing faces adapted for mating engagement; forming an annular groove in each of said opposing faces; forming a plurality of radial slots in each of said opposing faces which extend from the hollow interior to said annular groove; forming a cut out in each of said faces which extends from said annular groove to the periphery of said cylindrical wall; and joining said opposing faces together in such a way that said annular grooves form an annular channel, said radial slots form a plurality of radial channels and said cut outs form a port providing fluid communications between said annular groove and said sampling air tube.