A new approach for assessing sleep architecture and continuity measures through the analysis of heart rate and wrist movements
Journal of Clinical Sleep Medicine
The objective of the study was to evaluate the reliability of a new methodology for assessing sleep architecture parameters based on heart rate and body movement recordings instead of polysomnography. 12 healthy male and female subjects between 18 to 40 years, without sleep disorders and not taking any drug or medication that could affect sleep, were recorded continuously during 5 consecutive nights. Together with the standard polysomnography, heart rate was recorded with a Holter and wrist movements by actimetry. On the 60 recorded nights, 48 artifact-free nights were analyzed by two independent and well-trained visual scorers according to the rules of the American Academy of Sleep Medicine. Sleep stages were assigned to every 30-sec epochs. In parallel, the same nights were analyzed by the new methodology using only heart rate and actimetry data, allowing a 1-sec epoch sleep stage classification. An evaluation of the sleep architecture was performed for each of these 48 nights, independently for the two visual scorings and the automatic analysis. Over the 48 nights, the intra-class correlation coefficient, used to assess the consistency or reproducibility of quantitative measurements made by different observers measuring the same quantity, was classified as “excellent” for 10 and “good” for 2 of the 12 sleep parameters measured. In conclusion, the analysis of the heart rate and body movements during sleep allows for the evaluation of sleep architecture and continuity that is equivalent to the one obtained by polysomnography. The technique used here is simple and robust enough to allow for at-home sleep monitoring.