respiratory disturbance index in a group of adults indicating that the flip flop state index as related to a high respiratory disturbance if the flip flop state index was higher than 0 1 then it was predicted that patient was an osa patient this prediction was validated against rdi numbers calculated independently from these calculations roc and percentages of hits and misses were calculated in another group of apnea patients receiving cpap treatment a lower phase variability was found in the part of the night with a high cpap value than in the part of the night with a low cpap value normative values of the flip flop state index calculated from this data should provide a tool to help judge whether the pressure too high or too low while thoracic abdominal asynchrony taa is a known measure that has been used for copd other respiratory abnormalities and in paradoxical breathing during sleep it has not been used in diagnosis of apnea the study of paradoxical breathing where the phase angle between abdominal effort and thoracic effort is about 90 degrees has shown that long periods of paradoxical breathing are deleterious however no connection has been made between paradoxical breathing and apnea literature in this field has been more concerned with the absolute measure of phase angle rather than the rate of phase angle change with time the rate of change of phase angle correlates to the respiratory disturbance index the number of times arousal from.