Biomaterial Database

Nightcap: a reliable system for determining sleep onset latency. 2002

Jose L Cantero, and Mercedes Atienza, and Robert Stickgold, and J Allan Hobson

Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA. jose_cantero@hms.harvard.edu

Previous studies have demonstrated that the Nightcap home-based sleep-monitoring system can differentiate waking, NREM and REM sleep based on eyelid movements (ELMs) and head movement behavior. The present study aims at determining the reliability of the Nightcap in determining the human sleep onset latency (SOL) as revealed by standard polysomnography (PSG). Four naps were recorded in each of ten normal subjects using both PSG and the Nightcap simultaneously. The Nightcap algorithm scored sleep onset as the first of 4 consecutive 30-sec epochs with less than 5 ELMs. The mean percentage of agreement between the Nightcap and PSG was 93% (k = 0.79), and the average absolute difference was 45 sec (13.3% of SOL(PSG)). SOL(NC) differed by less than 1 min in 85% of onsets. Recordings of EEG activity from 90 sec before and after PSG-identified sleep onsets were subjected to spectral analysis. Changes in spectral power in the theta (4-7 Hz) and alpha (8-12 Hz) frequency bands during the transition into light sleep correlated well with eyelid behavior. However, changes in ELM density predicted sleep onset better than did changes in theta and alpha spectral power. These results suggest that the Nightcap may be a potential alternative to the PSG technique in the assessment of SOL in normal subjects.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009068	Movement	The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.	Movements
D004576	Electromyography	Recording of the changes in electric potential of muscle by means of surface or needle electrodes.	Electromyogram,Surface Electromyography,Electromyograms,Electromyographies,Electromyographies, Surface,Electromyography, Surface,Surface Electromyographies
D004867	Equipment Design	Methods and patterns of fabricating machines and related hardware.	Design, Equipment,Device Design,Medical Device Design,Design, Medical Device,Designs, Medical Device,Device Design, Medical,Device Designs, Medical,Medical Device Designs,Design, Device,Designs, Device,Designs, Equipment,Device Designs,Equipment Designs
D005143	Eyelids	Each of the upper and lower folds of SKIN which cover the EYE when closed.	Eyelid
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D012893	Sleep Wake Disorders	Abnormal sleep-wake schedule or pattern associated with the CIRCADIAN RHYTHM which affect the length, timing, and/or rigidity of the sleep-wake cycle relative to the day-night cycle.	Sleep Disorders,Long Sleeper Syndrome,Short Sleep Phenotype,Short Sleeper Syndrome,Sleep-Related Neurogenic Tachypnea,Subwakefullness Syndrome,Disorder, Sleep,Disorder, Sleep Wake,Disorders, Sleep,Disorders, Sleep Wake,Long Sleeper Syndromes,Neurogenic Tachypnea, Sleep-Related,Neurogenic Tachypneas, Sleep-Related,Phenotype, Short Sleep,Phenotypes, Short Sleep,Short Sleep Phenotypes,Short Sleeper Syndromes,Sleep Disorder,Sleep Phenotypes, Short,Sleep Related Neurogenic Tachypnea,Sleep Wake Disorder,Sleep-Related Neurogenic Tachypneas,Sleeper Syndrome, Long,Sleeper Syndrome, Short,Sleeper Syndromes, Long,Sleeper Syndromes, Short,Subwakefullness Syndromes,Syndrome, Long Sleeper,Syndrome, Short Sleeper,Syndrome, Subwakefullness,Syndromes, Long Sleeper,Syndromes, Short Sleeper,Syndromes, Subwakefullness,Tachypnea, Sleep-Related Neurogenic,Tachypneas, Sleep-Related Neurogenic,Wake Disorder, Sleep,Wake Disorders, Sleep
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor