Cited by 240Non-Invasive Vital Sign MonitoringContext-Aware Activity Recognition SystemsSleep and related disorders

Sleep stage prediction with raw acceleration and photoplethysmography heart rate data derived from a consumer wearable device

Open access
Walch, Olivia, Huang, Yitong, Forger, Daniel, Goldstein, Cathy·2019·Sleep

Abstract

Wearable, multisensor, consumer devices that estimate sleep are now commonplace, but the algorithms used by these devices to score sleep are not open source, and the raw sensor data is rarely accessible for external use. As a result, these devices are limited in their usefulness for clinical and research applications, despite holding much promise. We used a mobile application of our own creation to collect raw acceleration data and heart rate from the Apple Watch worn by participants undergoing polysomnography, as well as during the ambulatory period preceding in lab testing. Using this data, we compared the contributions of multiple features (motion, local standard deviation in heart rate, and “clock proxy”) to performance across several classifiers. Best performance was achieved using neural nets, though the differences across classifiers were generally small. For sleep-wake classification, our method scored 90% of epochs correctly, with 59.6% of true wake epochs (specificity) and 93% of true sleep epochs (sensitivity) scored correctly. Accuracy for differentiating wake, NREM sleep, and REM sleep was approximately 72% when all features were used. We generalized our results by testing the models trained on Apple Watch data using data from the Multi-ethnic Study of Atherosclerosis (MESA), and found that we were able to predict sleep with performance comparable to testing on our own dataset. This study demonstrates, for the first time, the ability to analyze raw acceleration and heart rate data from a ubiquitous wearable device with accepted, disclosed mathematical methods to improve accuracy of sleep and sleep stage prediction.

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Crossref · 10.1093/sleep/zsz180

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  • Algorithms for sleep stage classification have used PPG-derived HR, PRV, RR, pulse wave morphology, and accelerometry in combination with PPG.

    “Algorithms have used PPG-derived HR [221], PRV [222], [223], RR [222], pulse wave morphology [223], and accelerometry in combination with PPG [222].”

    From Wearable Photoplethysmography for Cardiovascular Monitoring (2022) · cites this paper as [221]

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Authors
Walch, O., Huang, Y., Forger, D., & Goldstein, C.
Affiliations
  • University of Michigan (US)
  • Dartmouth College (US)
Corresponding author
Walch, Olivia
Venue
Sleep
Published
2019-08-13
Volume
42
Issue
12
ISSN
  • 0161-8105 (ISSN-L)
  • 1550-9109
OpenAlex
W2937191485
Cited by
240
References
56
Citations by year
2026: 20 · 2025: 42 · 2024: 33 · 2023: 38 · 2022: 39 · 2021: 40 · 2020: 28
FWCI
9.43
Type
journal article
Language
en
Open access
Locations
  • SLEEP (publishedVersion, cc-by-nc)
  • PubMed Central (publishedVersion, cc-by-nc)
  • PubMed (publishedVersion)
  • Smith ScholarWorks (Smith College) (submittedVersion, cc-by-nc)
Funders
Exercise & Sport Science Initiative University of Michigan (U056400, U049702, NSF DMS 1714094)
Topics
  • Physical Sciences › Engineering › Biomedical Engineering › Non-Invasive Vital Sign Monitoring
  • Physical Sciences › Computer Science › Computer Vision and Pattern Recognition › Context-Aware Activity Recognition Systems
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
Keywords
wearable devices, Apple Watch, accelerometry, photoplethysmography, heart rate, sleep-wake classification, NREM sleep, REM sleep, polysomnography, artificial neural networks, classifier comparison, MESA, cross-dataset generalization
MeSH terms
Acceleration, Wearable Electronic Devices, Adult, Algorithms, Data Interpretation, Statistical, Electroencephalography, Female, Forecasting, Heart Rate, Humans, Male, Middle Aged, Sleep Stages, Photoplethysmography, Polysomnography, Young Adult

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