Patent ID: 9687177
Date: 2017-06-27
CPC Classifications: A61B,A61M,Y02A

Claim:
1. A method for controlling a processor to detect a sleep state from a measured flow of breathable gas, the method of the processor comprising: determining a plurality of respiratory characteristics from a measure of respiratory flow; detecting a sleep state from potential sleep states comprising a Non-REM sleep state and a REM sleep state, the detecting of the sleep state based on the determined respiratory characteristics, the detection of the sleep state based on data from the measure of flow from a flow sensor, the detecting of the sleep state not being based on data from electroencephalogram (E.E.G.), electromyography (E.M.G.) and electrooculography (E.O.G.) sensors; and indicating the detected sleep state, wherein the determined plurality of respiratory characteristics from which the sleep state is detected includes a set of two or more measures of (a) a measure of expiratory peak flow variation derived from a plurality of breaths, (b) a measure of a ratio of an expiratory peak flow location and expiratory time, (c) a measure of an expiratory peak flow location variation derived from a plurality of breaths, (d) a measure of an area of an expiratory peak flow, (e) a measure of an area of an expiratory peak flow variation, (f) a measure of a time from expiratory peak flow to inspiration start, (g) a measure of a time since last confirmed breath variability, (h) a measure of a high breath frequency period, and (i) a measure of inspiratory time variability.