Sensing for respiratory circuits

Abstract

Some embodiments provide a breathing assistance apparatus comprising a conduit for conveying gases therein, the conduit comprising circuitry. The circuitry may comprise at least one heater wire part to heat gases in the conduit, in use, and at least one sensor wire part comprising at least one sensor for monitoring a parameter of the gases in the conduit. There is also provided a controller to control provision of AC power or AC voltage to the heater wire part; and control selective reading of the sensor. The controller may be configured to read the sensor at or about a particular portion of the AC power waveform provided to the heater wire part.

Dependencies are inferred from the claim text.