A method and system for reliably estimating inspiration- to-expiration ratio from an acoustic physiological signal. A background sound level is set to an energy level whereat a predetermined share of data points on an energy envelope is below the energy level, after which respiration phase start and end times are determined at energy crossings above the background sound level, enabling more reliable determination of respiration phases. Moreover, reliably determined respiration phase start and end times, in addition to being used to estimate inspiration-to-expiration ratio, are applied to other purposes, such as estimating respiration period, validating an independently computed respiration period and/ or adjusting a sampling window of the acoustic physiological signal, reducing system complexity and conserving computational resources.
METHOD AND SYSTEM FOR RELIABLE INSPIRATION-TO-EXPIRATION RATIO EXTRACTION FROM ACOUSTIC PHYSIOLOGICAL SIGNAL