Method and device for monitoring sleep

A method for detecting at least one breathing parameter, which is characteristic for the breathing status of a sleeping subject, comprising the steps of: measuring the time course of at least one repeatedly changing breathing state quantity of the cardiovascular system of said subject; Determining respiration intervals each representing the duration of one breath, from the results of measurement; and determination of the statistical variables derived therefrom, is formed by the variability of the respiration intervals in phases nichtobstruierter breathing and / or respiration parameter. Also described are uses of the method in the control of ventilation equipment and in the signaling of respiratory states of sleeping subject and apparatus for implementing the method.