A non-intrusive and quantitative method and apparatus for diagnosing sleep apnea
and detecting apnea events by monitoring during sleep abdominal effort and thoracic
effort, determining the phase of each effort, determining the difference in phase
between each type of effort, and then determining the rate of phase angle change
and standard deviation over time. Also provided may be treatment when apnea events
are detected to trigger therapy apparatus such as airway positive pressure apparatus.