A method and system for the analysis of a patient's oximetry data to detect sleep-disordered breathing is provided. The system employs an algorithm to reliably detect patient arousals and correlate those with accelerated heart rate and oxygen saturation levels in a manner that detects sleep-disordered breathing via the respiratory mask. Initially a timing channel is formed based on a plethsmography signal using an optical finger sensor. Based on the pleth waveform, a respiratory wave form is prepared that represents respiration rate. An arousal mask is applied to the signal based on attenuations in the pleth signal. Once arousals are identified the time required for changes to propagate from the lungs to the blood gas is subtracted from the onset time of the arousal. As a result if the timing agrees with dropping oxygen saturation or falling arterial pH then the arousal is indicated as a chemoreflex related arousal.
