Patent ID: 6802314
Filing Date: 2004-10-12
Classification: A61M,G01F,G08B,Y10S

Abstract:
Humidification apparatus for humidifying a gas flow to be supplied to a patient or other person in need of such gas comprising:humidification chamber means for holding a quantity of water and having an inlet and an outlet to allow said gas flow to pass through said humidification chamber means, gas flow temperature sensing means for sensing the gas temperature within or adjacent said humidification chamber means, heating means provided adjacent said humidification chamber means for providing heat to said quantity of water in said humidification chamber means in order to provide water vapour to said gas flow passing through said humidification chamber means, heating means power utilisation sensing means for monitoring power being used by said heating means, temperature sensing means for sensing the temperature of said heating means, gas transportation pathway means connected to said outlet of said humidification chamber means for conveying said gas flow to said patient or other person in need of such gas, said gas transportation pathway means having a patient end, distal to said end connected to said outlet of said humidification chamber means, alarm means for providing a warning signal after a predetermined alarm time, and a controller connected to said gas flow temperature sensing means, said heating means temperature sensing means and said heating means power utilization sensing means, said controller configured to: i) determine a difference temperature by subtracting the gas temperature determined by said gas flow temperature sensing means from the temperature sensed by said temperature sensing means, ii) determine a power requirement value for the heating means from said heating means power utilisation sensing means, iii) calculate a thermal conductivity value by dividing said power requirement value by said difference temperature, iv) activate said alarm means if said calculated thermal conductivity value is less than a predetermined minimum allowable thermal conductivity value, wherein said controller provides that said humidification apparatus is configured to sense the temperature of the heating means, sense the gas flow temperature and sense the power used by said heating means and calculate thermal conductivity based on what is sensed, and output an alarm depending on the calculated thermal conductivity.