“Rhythm” was designed to automatically generates daily sleep time via smartphone use behaviors. We use App-recorded midpoint of sleep time to assess circadian rhythm. The correlation of App-recorded and self-reported circadian rhythm reach 90.4% in our study.


【Android version over 5.1】

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. 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.

2.  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


Room A3234, No. 35 Keyan Road, Zhunan Town, Miaoli County 35053, Taiwan
TEL: 886-37206166 EXT 36383

E-mail: yuhsuanlin@nhri.org.tw