Humidification arrangement for a respiratory apparatus

A conduit for providing respiratory therapy to a patient, the conduit comprising:

• a first end that is configured to be connected to a flow generator device to receive a flow of pressurized gas for respiratory therapy generated by the flow generator device;
• a second end that is configured to be connected to a patient interface apparatus to provide the flow of pressurized gas to a patient;
• a central fluid passageway extending between the first end and the second end, wherein the central fluid passageway is configured to convey the flow of pressurized gas from the flow generator device to the patient interface apparatus;
• a helical tubular channel that forms a portion of the conduit by being wrapped around the central fluid passageway and extending between the first end and the second end in a spiral configuration, wherein the helical tubular channel is configured to contain a fluid volume that is spaced apart from the flow of pressurized gas to be conveyed through the central fluid passageway;
• and
• a heating element that forms another portion of the conduit by being wrapped around the central fluid passageway adjacent to the spiral configuration of the helical tubular channel, wherein an outer wall of the helical tubular channel is adjacent to and in contact with an outer wall of the heating element, and wherein the conduit has a varied outer circumference along its length.

A method of using a conduit for providing respiratory therapy, the method comprising:

• connecting a first end of the conduit to a flow generator device, the conduit including:
• a central fluid passageway extending between the first end and a second end, a helical tubular channel that forms a portion of the conduit by being wrapped around the central fluid passageway and extending between the first end and the second end in a spiral configuration, and a heating element that forms another portion of the conduit by being wrapped around the central fluid passageway adjacent to the spiral configuration of the helical tubular channel, wherein the helical tubular channel forms an inner wall of the central fluid passageway;
• connecting the second end of the conduit to a patient interface apparatus;
• and
• providing a flow of pressurized gas from the flow generator device, through the central fluid passageway of the conduit, and to the patient interface apparatus for respiratory therapy both while the helical tubular channel contains a fluid volume along the spiral configuration that is spaced apart from the flow of pressurized gas conveyed through the central fluid passageway and while the heating element supplies heat to the pressurized gas conveyed through the central fluid passageway.