Breathing assistance apparatus

A breathing assistance apparatus adapted to deliver humidified gases at a desired level of humidity, flow and temperature for treatment of a patient, the apparatus comprising:

• a) a gases supply arrangement providing a flow of gases, b) a humidifier having a chamber adapted to receive a volume of water and a chamber heater to heat the water in the chamber, the chamber including an inlet and an outlet,
• c) a transportation pathway to convey the humidified gases from the humidifier to the patient, the transportation pathway comprising a pathway heater having a distal end and a proximal end, the proximal end being adjacent the humidifier, the pathway heater being configured to heat the transportation pathway, and
• d) a controller having stored instructions to complete the following steps following a conclusion of treatment of the patient:
• i) switch off power to the chamber heater,
• ii) set the flow of gases from the gases supply arrangement for a predetermined time, and switch off power to the chamber heater for at least a portion of the predetermined time, and
• iii) after the predetermined time, switch off the gases supply arrangement, and
• e) wherein the controller includes stored instructions to determine the conclusion of treatment of the patient when a substantial increase of flow of gases is detected exiting the gas supply arrangement for a second predetermined period of time.