Patent ID: 11938268
Assignee: RESMED PTY LTD
Field: Medical technology (Instruments)
Classification: CPC A  H | IPC A

Claim 0:
1. An apparatus for providing a supply of humidified pressurized breathable gas to a patient interface, the apparatus comprising: a flow generator configured to pressurize a supply of breathable gas; a humidifier configured to provide water vapour to humidify the supply of pressurized breathable gas; a heated tube configured to be connectable to the humidifier to heat and deliver the humidified supply of breathable gas to the patient interface; a sensor configured to measure a property of the humidified supply of breathable gas in the heated tube; a controller configured to control power provided to the heated tube and control operation of the flow generator; a set of low pass filters coupled between the sensor and the controller and a set of high pass filters coupled between the sensor and ground; and wherein the power supplied to the heated tube comprises a pulse width modulated power signal and at least a set of low pass filters is configured to filter frequencies near the frequencies of the pulse width modulated power signal and frequencies higher than the frequencies of the pulse width modulated power signal.