Humidified gases delivery apparatus

Abstract

A gases transportation pathway for use in supplying a humidified gases stream to a patient includes regulated conduit heating. The regulated conduit heating may include a section of positive temperature coefficient material wherein the localised electrical resistance of the material is positively related to the localised temperature. The regulated conduit heating may be a layer of positive temperature coefficient material within the wall of the gases transportation pathway with at least a pair of conductors running the length of the pathway and in electrically conductive contact with the positive temperature coefficient material.

1 . A gases transportation pathway for transporting humidified gases to a patient, said pathway comprising: 
 an enclosing wall including at least a layer of positive temperature coefficient material wherein the localised electrical resistance of said material is positively related to the localised temperature, and    at least two electrical conductors running the length of said pathway and disposed in electrical contact with said positive temperature coefficient material.    
     
     
         2 . A gases transportation pathway as claimed in  claim 1  wherein said wall includes at least one helically arranged ribbon of positive temperature coefficient material with adjacent turns of ribbon overlapping and fused to one another.  
     
     
         3 . A gases transportation pathway as claimed in  claim 2  wherein said conductors are arranged helically along said gases transportation pathway at least substantially constantly spaced from one another along the length of said gases transportation pathway.  
     
     
         4 . A gases transportation pathway as claimed in  claim 3  wherein at least a pair of said conductors are disposed within a said ribbon of positive temperature coefficient material, in constant position in relation to said ribbon.  
     
     
         5 . A gases transportation pathway as claimed in any one of claims I to  4  wherein said positive temperature coefficient material has a phase transformation temperature between 35° C. and 40° C.