Abstract: Methods and apparatus for determining the occurrence of an apnea, patency and/or partial obstruction of the airway are disclosed. Respiratory air flow from a patient is measured to give an air flow signal. The determination of an apnea is performed by calculating the variance of the air flow signal over a moving time window and comparing the variance with a threshold value. One determination of partial obstruction of the airway is performed by detecting the inspiratory part of the air flow signal, scaling it to unity duration and area and calculating an index value of the amplitude of the scaled signal over a mid-portion. Alternatively, the index value is a measure of the flatness of the air flow signal over the mid-portion.

Abstract: Methods and apparatus for determining the occurrence of an apnea, patency and/or partial obstruction of the airway are disclosed. Respiratory air flow from a patient is measured to give an air flow signal. The determination of an apnea is performed by calculating the variance of the air flow signal over a moving time window and comparing the variance with a threshold value. One determination of partial obstruction of the airway is performed by detecting the inspiratory part of the air flow signal, scaling it to unity duration and area and calculating an index value of the amplitude of the scaled signal over a mid-portion. Alternatively, the index value is a measure of the flatness of the air flow signal over the mid-portion.

Abstract: A combination mouth and nasal mask (40) for assisted respiration or CPAP is disclosed.The combination mask (40) has a frame (42) to the rear side of which is mounted a separate nasal cushion (44) and mouth cushion (46). Both the nasal cushion (44) and the mouth cushion (46) separately form a rolled edge seal around the patient's face in the vicinity of the nose and in the vicinity of the lips. Inlet air is communicated from within the housing (48) to the mouth chamber, circumscribed by the mouth cushion (46) by means of one or more interconnecting tubes (62).The proportion of air communicated to the mouth chamber (48) is controlled by the sizing and number of the tube(s), thus providing for free flow of air, restricted flow of air and pressure equalisation, or zero flow of air.A mouth mask (10) for assisted respiration or CPAP also is disclosed.