US Patent 7588029 Humidified gases delivery apparatus

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 localized electrical resistance of the material is positively related to the localized 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.