“Rhythm” is a smartphone-based automatic sleep recording system. It tracks smartphone-use patterns to derive sleep times and analyzes changes in sleep patterns. It has an accuracy of 90.4% for sleep-time estimation and a consistency of 87% for circadian rhythm fluctuation, demonstrating the app’s reliability. It also displays sleep patterns graphically, and notes how sleep patterns differ between weekdays and weekends, helping users avoid social jet lag.


【Android version over 9.0】

The App “Rhythm” automatically recorded smartphone behaviors, mainly the notifications, screen-on and screen-off timing. This App collects data in the background without interrupting smartphone operation or impacting battery life (less than 1%). The App saves all recorded behavior data in a log file and routinely uploaded to the database.

Our previous study has preliminarily validated the consistency between App-recorded and self-reported sleep time. The overlap of total sleep time between App-record and self-reported was 90.4%.


1. Interpretation of Daily Human Behavior via Smartphone Digital Footprints: Examples from Smartphone Use, Sleeping Patterns, and Working Hours

Chiang TW, Chen SY, Lin YH.
Data Science:Survey Research-Method and Application. 2020 Oct;(No.45)043-071.

2. Validation of the Mobile App-Recorded Circadian Rhythm by a Digital Footprint.

Lin YH, Wong BY, Pan YC, Chiu YC, Lee YH.
JMIR Mhealth Uhealth. 2019 May 16;7(5):e13421.

3. Development of a mobile application (App) to delineate “digital chronotype” and the effects of delayed chronotype by bedtime smartphone use.

Lin YH, Wong BY, Lin SH, Chiu YC, Pan YC, Lee YH.
Journal of Psychiatric Research. 2019 Mar;110:9-15.

Rhythm's Introduction Video

Rhythm's Infographic Video

Rhythm's Press Conference

NHRI Digital Biomarkers Lab
Room A3234, No. 35 Keyan Road, Zhunan Town, Miaoli County 35053, Taiwan
886-37-206166 EXT 36383 | yuhsuanlin@nhri.org.tw