CPC A61M 16/0069 (2014.02) [A61M 16/0051 (2013.01); A61M 16/026 (2017.08); A61M 16/109 (2014.02); A61M 16/16 (2013.01); A61M 16/161 (2014.02); A61M 2205/15 (2013.01); A61M 2205/18 (2013.01); A61M 2205/3368 (2013.01); A61M 2205/3386 (2013.01); A61M 2205/502 (2013.01); A61M 2205/581 (2013.01); A61M 2205/583 (2013.01)] | 9 Claims |
1. A method for adding humidity to gas delivered by a positive airway pressure apparatus, the method comprising:
producing, with a blower, a flow of pressurized gas at a variable flow rate;
transporting the flow of pressurized gas from the blower to a user interface via a delivery tube positioned between the blower and the user interface;
detecting, with a controller, one or both of an inspiratory phase and an expiratory phase of one or more breath cycles;
introducing, during a power interval, humidity into a portion of the flow of pressurized gas to produce a discrete flow of pressurized gas with added humidity, the humidity introduced by a vaporizing device having an outlet proximate the blower and in communication with the flow of pressurized gas; and
determining, automatically with the controller, a start time and duration of the power interval so that the flow of pressurized gas with added humidity reaches the user interface at or near an onset of an inspiratory phase of a current or future breath cycle and ends at or near an end of the inspiratory phase, or at or near an onset of an expiratory phase, of the current or future breath cycle, wherein determining the start time and duration of the power interval comprises:
measuring one or more characteristics of a previous breath cycle;
determining ideal values of the start time and duration of the power interval for the previous breath cycle;
comparing the ideal values of the start time and duration of the power interval for the previous breath cycle to actual values of the start time and duration used;
calculating an error between the ideal values and the actual values of the start time and duration of the power interval for the previous breath cycle; and
predicting the start time and duration of the power interval for the current or future breath cycle based at least in part upon the error calculated.
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