Abstract: A method and apparatus for determining the air pressure in a lung comprises making a determination of the velocity of sound in the lung and estimating the pressure within the lung based on the determined velocity. The method also includes determining a difference in phase for sound between two positions with respect to the lung.

Abstract: A method of differentiating between OSA and CSA comprising: determining if chest motion above a chest motion threshold is present; determining if tracheal breath sound above a breath sounds threshold are present, classifying a state as OSA if the chest motion is above the threshold and the sounds are below the threshold; and classifying a state as CSA if both the chest motion and sounds are below their respective thresholds.

Abstract: A method of analyzing breath sounds produced by a respiratory system, the method comprising: measuring breath sounds produced by the respiratory system; tentatively identifying a signal as being caused by a breath sound of a given type if it meets a first criteria characteristic of the breath sound of the given type; and confirming said identification if a tentatively identified signal meets a second criteria characteristic of the breath sound of the given type.

Abstract: A phonopneumograph system for analyzing breath sounds includes a plurality of breath related sensors placed around the respiratory system of a patient for measuring breath related activity and a breath analyzer. The breath analyzer matches the breath sound data produced by the breath related sensors to a plurality of breath sound templates each of which parametrize one type of breath sound and determines the presence of regular and/or adventitious breath sounds only when the breath sound data matches, within predetermined goodness of fit criteria, one or more of the breath sound templates.