A Comparison of Inertial Measurement Units and Overnight Videography to Assess Sleep Biomechanics

Nicholas Buckley; Paul Davey; Lynn Jensen; Kevin Baptist; Angela Jacques; Bas Jansen; Amity Campbell; Jenny Downs

doi:10.3390/bioengineering10040408

A Comparison of Inertial Measurement Units and Overnight Videography to Assess Sleep Biomechanics

Bioengineering (Basel). 2023 Mar 25;10(4):408. doi: 10.3390/bioengineering10040408.

Authors

Nicholas Buckley^{1

2}, Paul Davey¹, Lynn Jensen³, Kevin Baptist⁴, Angela Jacques⁵, Bas Jansen⁴, Amity Campbell¹, Jenny Downs^{1

2}

Affiliations

¹ Curtin School of Allied Health, Curtin University, Perth 6102, Australia.
² Telethon Kids Institute, Perth 6009, Australia.
³ Physiotherapy Department, Perth Children's Hospital, Perth 6009, Australia.
⁴ Ace Therapy Services, Perth 6021, Australia.
⁵ Institute for Health Research, University of Notre Dame Australia, Fremantle 6160, Australia.

Abstract

Purpose: The assessment of sleep biomechanics (comprising movement and position during sleep) is of interest in a wide variety of clinical and research settings. However, there is no standard method by which sleep biomechanics are measured. This study aimed to (1) compare the intra- and inter-rater reliability of the current clinical standard, manually coded overnight videography, and (2) compare sleep position recorded using overnight videography to sleep position recorded using the XSENS DOT wearable sensor platform.

Methods: Ten healthy adult volunteers slept for one night with XSENS DOT units in situ (on their chest, pelvis, and left and right thighs), with three infrared video cameras recording concurrently. Ten clips per participant were edited from the video. Sleeping position in each clip was coded by six experienced allied health professionals using the novel Body Orientation During Sleep (BODS) Framework, comprising 12 sections in a 360-degree circle. Intra-rater reliability was assessed by calculating the differences between the BODS ratings from repeated clips and the percentage who were rated with a maximum of one section of the XSENS DOT value; the same methodology was used to establish the level of agreement between the XSENS DOT and allied health professional ratings of overnight videography. Bennett's S-Score was used to assess inter-rater reliability.

Results: High intra-rater reliability (90% of ratings with maximum difference of one section) and moderate inter-rater reliability (Bennett's S-Score 0.466 to 0.632) were demonstrated in the BODS ratings. The raters demonstrated high levels of agreement overall with the XSENS DOT platform, with 90% of ratings from allied health raters being within the range of at least 1 section of the BODS (as compared to the corresponding XSENS DOT produced rating).

Conclusions: The current clinical standard for assessing sleep biomechanics, manually rated overnight videography (as rated using the BODS Framework) demonstrated acceptable intra- and inter-rater reliability. Further, the XSENS DOT platform demonstrated satisfactory levels of agreement as compared to the current clinical standard, providing confidence for its use in future studies of sleep biomechanics.

Keywords: XSENS DOTs; overnight videography; sleep biomechanics.

Grants and funding

The authors declare that no funds, grants, or other support was received during the preparation of this manuscript, with the exception of the living expenses stipend received by Nicholas Buckley as part of the Research Training Program scholarship (administered by Curtin University).