The accuracy of the THIM wearable device for estimating sleep onset latency

Hannah Scott, Ashwin Whitelaw, Alex Canty, Nicole Lovato, Leon Lack

Research output: Contribution to journalArticlepeer-review


STUDY OBJECTIVES:THIM is a wearable device designed to accurately estimate sleep onset. This article presents two studies that tested the original (Study 1) and a refined (Study 2) THIM sleep onset algorithms compared to polysomnography (PSG). METHODS:Twelve (Study 1) and twenty (Study 2) individuals slept in the laboratory on two nights where participants underwent THIM-administered sleep onset trials with simultaneous PSG recording. Participants attempted to fall asleep whilst using THIM, which woke them once it determined sleep onset. RESULTS:In Study 1, there was no significant difference between PSG (Mean, M = 1.94 min, SD = 1.32) and THIM-sleep onset latency (M = 2.05 min, SD = 1.38) on the first or second night, p > .07. There were moderate correlations between PSG and THIM on both nights, r(s) > .57, p < .001. On 23.74% of trials, PSG-sleep onset could not be determined before THIM ended the trial. With a revised THIM algorithm in Study 2, there was no significant difference between PSG (M = 3.41 min, SD = 2.21) and THIM-sleep onset latency (M = 3.65 min, SD = 2.18), p = .25, strong correspondence between the two devices, r(s) > .73, p < .001, narrow levels of agreement on Bland-Altman plots, and significantly less trials where PSG-sleep onset had not occurred (10.24%), p = .04. CONCLUSIONS:THIM showed a high degree of correspondence and agreement with PSG for estimating sleep onset. Future research will investigate whether THIM is accurate with an insomnia sample for clinical purposes.
Original languageEnglish
JournalJournal of Clinical Sleep Medicine
Publication statusE-pub ahead of print - 13 Jan 2021


  • wearable device
  • Consumer sleep technology
  • Polysomnography
  • Actigraphy
  • Sleep onset latency
  • Intensive sleep retraining

Fingerprint Dive into the research topics of 'The accuracy of the THIM wearable device for estimating sleep onset latency'. Together they form a unique fingerprint.

Cite this