Validity of Two Consumer Multisport Activity Tracker and One Accelerometer against Polysomnography for Measuring Sleep Parameters and Vital Data in a Laboratory Setting in Sleep Patients

Abstract

Two commercial multisport activity trackers (Garmin Forerunner 945 and Polar Ignite) and the accelerometer ActiGraph GT9X were evaluated in measuring vital data, sleep stages and sleep/wake patterns against polysomnography (PSG). Forty-nine adult patients with suspected sleep disorders (30 males/19 females) completed a one-night PSG sleep examination followed by a multiple sleep latency test (MSLT). Sleep parameters, time in bed (TIB), total sleep time (TST), wake after sleep onset (WASO), sleep onset latency (SOL), awake time (WASO + SOL), sleep stages (light, deep, REM sleep) and the number of sleep cycles were compared. Both commercial trackers showed high accuracy in measuring vital data (HR, HRV, SpO2, respiratory rate), r > 0.92. For TIB and TST, all three trackers showed medium to high correlation, r > 0.42. Garmin had significant overestimation of TST, with MAE of 84.63 min and MAPE of 25.32%. Polar also had an overestimation of TST, with MAE of 45.08 min and MAPE of 13.80%. ActiGraph GT9X results were inconspicuous. The trackers significantly underestimated awake times (WASO + SOL) with weak correlation, r = 0.11–0.57. The highest MAE was 50.35 min and the highest MAPE was 83.02% for WASO for Garmin and ActiGraph GT9X; Polar had the highest MAE of 21.17 min and the highest MAPE of 141.61% for SOL. Garmin showed significant deviations for sleep stages (p < 0.045), while Polar only showed significant deviations for sleep cycle (p = 0.000), r < 0.50. Garmin and Polar overestimated light sleep and underestimated deep sleep, Garmin significantly, with MAE up to 64.94 min and MAPE up to 116.50%. Both commercial trackers Garmin and Polar did not detect any daytime sleep at all during the MSLT test. The use of the multisport activity trackers for sleep analysis can only be recommended for general daily use and for research purposes. If precise data on sleep stages and parameters are required, their use is limited. The accuracy of the vital data measurement was adequate. Further studies are needed to evaluate their use for medical purposes, inside and outside of the sleep laboratory. The accelerometer ActiGraph GT9X showed overall suitable accuracy in detecting sleep/wake patterns.

Acute beetroot juice reduces blood pressure in young Black and White males but not females

“…Sleep duration regularity (sleep SD) was operationalized using the standard deviation (SD) of nightly sleep duration [ 60 ]. The validity of GT9X-derived sleep parameters has been previously established against gold-standard polysomnography [ 61 ].…”

Characteristics of macroscopic sleep structure in patients with mild cognitive impairment: a systematic review

“…It is recommended by the American Academy of Sleep Medicine (AASM) as a home sleep monitoring measurement for healthy adults and patients with particular sleep disorder types ( 17 ). Most Actigraphy devices can only be used for determining sleep-wake patterns and cannot detect or further analyse sleep stages (light, deep, or REM sleep) ( 18 ). PSG monitoring is based on information that is recorded on the EEG, EOG, and chin EMG for determining wakefulness and sleep stages together.…”

“…According to the AASM Handbook for the Interpretation of Sleep and Related Events ( 20 ) and the Handbook of Standardized Terminology, Techniques and Classification Systems for Human Sleep Stages by Rechtschaffen and Kales ( 21 ), PSG measures the following sleep structure parameters: light out time (hh: mm), light on time (hh: mm), total recording time (TRT; min), SL (min), TST (min), WASO (min), REML (min), SE (%), wake time (min), non-rapid eye movement (NREM) sleep duration, including N1 (S1) stage sleep time (min), N2 (S2) stage sleep time (min) and N3 [S3+S4/slow wave sleep (SWS)] stage sleep time (min), REM sleep time (min), the proportion of each sleep stage [N1 (S1), N2 (S2), N3 (S3+S4/SWS), REM)](%), number of awakenings (times) and arousal index (AI; times/hour) ( 22 ). Most Actigraphy devices also measure the following structural parameters of sleep: time in bed (TIB; min), TST (min), mean activity during TIB (AMEAN; min), sleep minutes during TIB (SMIN; min), SE, WASO (min), latency to persistent sleep (min), SL (min), mean sleep episode (MSEP; min), long sleep episodes (LSEPs; min), longest sleep episode (LGSEP; min), waking minutes (min), activity index (ACTX), number of awakenings (times), AI (times/hour) and sleep fragmentation index (SFI) ( 18 , 23 ). The main objective measures and measurement criteria that are included in this study are TST, which is the sum of the actual sleep time between the time the lights are switched off and the time they are turned on, i.e., the sum of the time in each sleep period; SE, which is TST/TRT × 100%; WASO, which is the sum of all waking times between the first sleep frame and the conclusion of the recording; SL, which is the time from the start of recording to the appearance of the first sleep epoch; REML, which is the time from the first sleep epoch to the first REM stage; the proportion of each sleep period (%), which is the percentage of sleep time in each sleep stage [N1 (S1), N2 (S2), N3 (S3+S4), REM stage] of total sleep time; the number of awakenings (times) that occur during sleep; and AI (times/hour), which is the number of arousals that occur for each hour of sleep ( 22 , 23 ).…”

Performance Evaluation of a New Sport Watch in Sleep Tracking: A Comparison against Overnight Polysomnography in Young Adults

“…Sleep deprivation can negatively impact decision making, increase anxiety and irritability, and elevate the risk of cardiovascular and gastrointestinal diseases, mental illness, and cancer [1]. Moreover, sleep plays a key role in cognitive function and physical recovery that can affect academic performance and sports performance [1][2][3][4][5]. Objective sleep quality measurements derived from wearables could provide an alternative opportunity to the use of sleep diaries to analyze individuals' sleep patterns for a prolonged period of time and suggest changes to sleep hygiene and the implementation of behavioral interventions that could prevent the negative health consequences of poor sleep [6,7].…”

“…Different commercial sleep tracking wearables have become available during the last decade (Table 1). For example, wrist actigraphy utilizes an accelerometer built in a wristwatch, and it records movement as a surrogate measurement of wakefulness and inactivity as a proxy measurement of sleep [3,12]. The majority of first-generation sleep trackers included a tri-axial accelerometer to use movement data to determine sleep/awake timing [7].…”