[Cardiogenic oscillation--utility of classifying types of sleep apnea].

Cardiogenic pulse waves that travel along the airway wall are captured as airflow variations synchronized with the electrocardiogram at the airway exit. We have used airflow variations caused by cardiogenic pulse waves (hereinafter referred to as cardiogenic oscillation) to classify types of sleep apnea. Pulse waves do not travel downstream if there is an airway obstruction or choke point (wave speed theory).