SLEEP APNEA MONITORING AND DIAGNOSIS BASED ON PULSE OXIMETERY AND TRACHEAL SOUND SIGNALS

摘要

Detection of apnea/hypopnea events to calculate an apnea/hypopneaindex is obtained by analysis of breathing pattern of a patient from breathingandsnore sounds and a finger probe recording the SaO2 signal. A detector analyzesmicrophone signals to detect breath, snore and noise sounds in response to adetected drop in the SaO2 level greater than 2% and to extract and analyze thebreathing sounds from a limited time period starting prior to the drop of theSaO2signal and ending at least at the end of each drop. Separated time periods aredivided phases with snore sounds and those with breathing sounds and anestimated breathing volume adjacent to a snore phase is used to estimate theairflow of the snore phase. The relative and absolute energy and duration ofthesound periods is used to classify the sound periods into the three groups ofbreath,snore and noise.