Researchers at Beth Israel Deaconess Medical Center (Boston, Mass) may have created a less costly alternative to determine the stability and quality of sleep. The method, known as a "sleep spectrogram," uses information hidden in the beat-to-beat changes of the heart's electrical signals.
Using training and datasets of 35 polysomnograms each, the researchers evaluated the relationship of an electrocardiogram- based measure of cardiopulmonary interaction with respect to standard sleep staging, as well as to the cyclic alternating pattern classification. The researchers also assessed the pattern of coupling in 15 healthy participants. The results of the study, reported in Sleep (September 1, 2005), showed that non-rapid-eye-movement sleep in adults indicates a spontaneous abrupt transition between high-and low-frequency cardiopulmonary coupling regimens. The investigators concluded that the sleep spectrogram might be used to help understand the mechanisms of sleep control, identify sleep disorders, and test the effectiveness of sleep aids and other medications.