Validation of an automated wireless system to monitor sleep in healthy adults

The availability of a reliable system to record sleep stage measures easily and automatically in ambulatory settings could be of utility for research and clinical work. The aim of this study was to evaluate a novel wireless system (WS) that does not require skilled preparation for the automatic collection and scoring of human sleep. Twenty-nine healthy adults underwent concurrent sleep measurement via the WS, polysomnography (PSG) and an actigraph (ACT) in a sleep laboratory for one assessment night preceded by an acclimation night. The PSG recordings were scored by two experienced trained technicians from separate laboratories. Each recording was scored by both technicians to Rechtschaffen and Kales (R&K) criteria. The WS and ACT were compared with each of the PSG scores and a consensus PSG score, and the PSG scores were compared with each other. Inter-rater agreement was assessed for each pair over all pooled epochs by percentage agreement, Cohen's kappa and intraclass correlation coefficient. The WS agreement with each of the two PSG scores for sleep stages was 75.8 and 74.7%, respectively. WS agreement with each of the two PSG scores for sleep/wakefulness was 92.6 and 91.1%, ACT agreement with PSG was 86.3 and 85.7%. The PSG scorers' agreement with each other for sleep stages was 83.2%, and for sleep/wakefulness was 95.8%. The findings from the current study indicate that the WS may provide an easy to use and accurate complement to other established technologies for measuring sleep in healthy adults.