Patent ID: 8322339

Claim:
A method of detecting a fault condition in a breathing assistance system for providing breathing assistance to a patient, the method performed by a control system configured to implement logic, instructions, and/or algorithms stored in computer readable storage media, the method comprising: the control system receiving from a pressure sensor a plurality of pressure measurements taken over time, each pressure measurement comprising a measurement of a gas pressure in the breathing assistance system; the control system determining a filtered pressure error value by comparing the plurality of pressure measurements to a target pressure value, the determination including filtering a plurality of values; the control system receiving from a flow sensor a plurality of flow rate measurements taken over time, each flow rate measurement comprising a measurement of a gas flow rate in the breathing assistance system; the control system filtering the plurality of flow rate measurements to determine a filtered flow rate value; and the control system comparing the filtered pressure error value to a pressure error threshold value; the control system determining the existence of a fault condition regarding the operation of the breathing assistance system, the fault condition determined based at least on both (a) the comparison of the filtered pressure error value to the pressure error threshold value and (b) the filtered flow rate value.