摘要 |
A method and apparatus for detecting and distinguishing epochs of deep-sleep from epochs of light-sleep of a subject by sensing by a peripheral pulse signal related to the systemic circulation of the subject, preferably a peripheral arterial tone (PAT) sensor for sensing pulsatile arterial volume changes in a digit (e.g., a finger) of the subject reflecting sympathetic tone variations; analyzing the sensed pulse signals for determining therefrom a number of features, particularly seven specific variables in each of two time periods; and utilizing the results of the analysis for determining whether the epoch detected is a light-sleep epoch or a deep-sleep epoch. |