Patent ID: 9440042
Filing Date: 2016-09-13
CPC Classification: A61M,G01F

Claim Text:
1. A method of determining an amount of water amount in a humidification chamber within a humidified gases delivery system, said method comprising: delivering power to a heater used to heat contents of a humidification chamber; varying the delivered power to the heater over a period of time; determining a plurality of temperature measurements from a temperature sensor over the period of time in the humidification chamber responsive to varying the delivered power; determining a temperature change trend from the plurality of temperature measurements over the period of time; determine a flow rate of air flowing through the humidification chamber from a flow sensor or a pressure sensor; calculating an evaporation rate of water in the humidification chamber over the period of time based on the flow rate of air flowing through the humidification chamber and the temperature change trend; comparing the evaporation rate with a predetermined trend comprising a look up table storing a plurality of values corresponding to a relationship between the evaporation rate and known water amounts in the humidification chamber; and determining the amount of water within the humidification chamber based on said comparison.