title: Validation of Contact-Free Sleep Monitoring Device with Comparison to Polysomnography.
abstract: OBJECTIVE
  To validate a contact-free system designed to achieve maximal comfort during long-term sleep monitoring, together with high monitoring accuracy.
  
  
  METHODS
  We used a contact-free monitoring system (EarlySense, Ltd., Israel), comprising an under-the-mattress piezoelectric sensor and a smartphone application, to collect vital signs and analyze sleep. Heart rate (HR), respiratory rate (RR), body movement, and calculated sleep-related parameters from the EarlySense (ES) sensor were compared to data simultaneously generated by the gold standard, polysomnography (PSG). Subjects in the sleep laboratory underwent overnight technician-attended full PSG, whereas subjects at home were recorded for 1 to 3 nights with portable partial PSG devices. Data were compared epoch by epoch.
  
  
  RESULTS
  A total of 63 subjects (85 nights) were recorded under a variety of sleep conditions. Compared to PSG, the contact-free system showed similar values for average total sleep time (TST), % wake, % rapid eye movement, and % non-rapid eye movement sleep, with 96.1% and 93.3% accuracy of continuous measurement of HR and RR, respectively. We found a linear correlation between TST measured by the sensor and TST determined by PSG, with a coefficient of 0.98 (R = 0.87). Epoch-by-epoch comparison with PSG in the sleep laboratory setting revealed that the system showed sleep detection sensitivity, specificity, and accuracy of 92.5%, 80.4%, and 90.5%, respectively.
  
  
  CONCLUSIONS
  TST estimates with the contact-free sleep monitoring system were closely correlated with the gold-standard reference. This system shows good sleep staging capability with improved performance over accelerometer-based apps, and collects additional physiological information on heart rate and respiratory rate.
authors.affiliation: Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev.
authors.forename: Asher
authors.initials: A
authors.lastname: Tal
authors.affiliation: EarlySense Ltd., Ramat Gan, Israel.
authors.forename: Zvika
authors.initials: Z
authors.lastname: Shinar
authors.affiliation: Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev.
authors.forename: David
authors.initials: D
authors.lastname: Shaki
authors.affiliation: Clalit Health Services, Beer Sheva, Israel.
authors.forename: Shlomi
authors.initials: S
authors.lastname: Codish
authors.affiliation: Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev.
authors.forename: Aviv
authors.initials: A
authors.lastname: Goldbart
mesh_terms: D056044:Actigraphy / Q000295:instrumentation / Q000379:methods; D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods*; D009068:Movement / Q000502:physiology; D017286:Polysomnography; D015203:Reproducibility of Results; D012119:Respiration; D012680:Sensitivity and Specificity; D012893:Sleep Wake Disorders / Q000175:diagnosis* / Q000503:physiopathology; D000068997:Smartphone; D055815:Young Adult
keywords: actigraphy; home sleep monitoring; polysomnography; sleep architecture