Cpap system

An apparatus for treating a respiratory disorder in a patient, the apparatus comprising:

• a motor-blower configured to generate a supply of air at a positive pressure relative to ambient pressure;
• a humidifier configured to provide water vapour to humidify the supply of pressurized air;
• a tube removably connected to the humidifier on one end and a patient interface on another end, the tube including one or more heating wires extending along the length of the tube and configured to heat the humidified supply of breathable air passed though the tube and one or more sensor wires extending along the length of the tube and coupled to a sensor configured to measure a property of the humidified supply of breathable gas in the tube;
• a controller including circuitry configured to control power provided to the one or more heating wires, control operation of the motor-blower, and control operation of the humidifier;
• and
• one or more high pass filters coupled between the one or more sensor wires and ground.