New Technique for Studying Sleep

Researchers at Beth Israel DeaconessMedical Center (Boston, Mass) may havecreated a less costly alternative to determinethe stability and quality of sleep. Themethod, known as a "sleep spectrogram," uses information hidden in the beat-to-beatchanges of the heart's electrical signals.

Using training and datasets of 35polysomnograms each, the researchersevaluated the relationship of an electrocardiogram-based measure of cardiopulmonaryinteraction with respect to standardsleep staging, as well as to the cyclic alternatingpattern classification. The researchersalso assessed the pattern of coupling in15 healthy participants. The results of thestudy, reported in Sleep (September 1,2005), showed that non-rapid-eye-movementsleep in adults indicates a spontaneousabrupt transition between high-andlow-frequency cardiopulmonary couplingregimens. The investigators concluded thatthe sleep spectrogram might be used tohelp understand the mechanisms of sleepcontrol, identify sleep disorders, and testthe effectiveness of sleep aids and othermedications.