Zone heating for respiratory circuits

A medical tube comprising:

• a first segment and a second segment, each segment comprising:
• an elongate hollow body spirally wound to form an elongate tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall surrounding the lumen, wherein the elongate hollow body has in a transverse cross-section a wall defining at least a portion of the lumen of the elongate tube;
• a reinforcement portion extending along a length of the elongate hollow body being spirally wound between adjacent turns of the elongate hollow body, wherein the reinforcement portion defines at least a portion of the lumen of the elongate tube and is more rigid than the wall of the elongate hollow body;
• and
• one or more conductive filaments embedded or encapsulated within the reinforcement portion;
• and
• a segment connector adapted to connect the first segment to the second segment, the segment connector comprising:
• connection pads configured to couple the one or more conductive filaments from the first segment to the one or more conductive filaments from the second segment;
• and
• a power diode coupled to the connection pads,
• wherein the power diode prevents power of a first polarity that is delivered to the one or more conductive filaments of the first segment from being delivered to the one or more conductive filaments of the second segment, and
• wherein the power diode allows power of a second polarity that is delivered to the one or more conductive filaments of the first segment to be delivered to the one or more conductive filaments of the second segment,
• wherein a heater circuit comprising the one or more conductive filaments of the first and second segments is independent of another heater circuit that heats another tube.