“Rhythm” is an automated, smartphone-based sleep recording application. It tracks smartphone use patterns to derive sleep times and analyze changes in sleep patterns. It has an accuracy of 90.4% for estimating sleep times and a consistency of 87% for detecting fluctuations in circadian rhythms, both of which demonstrate 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 lags. 


【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%.

Application Scope and Market Potential 

The technology of “Rhythm” can automatically estimate sleep time, sleep interruption time, and quantify sleep stability from mobile phone usage behavior. With its extremely low power consumption advantage, it can perform long-term objective recording, providing more objective record accuracy, and reflecting the user’s circadian rhythm. This can help understand the impact of using mobile phones before sleep on sleep and the impact of long-term sleep behavior on health. It is a significant breakthrough in behavioral measurement methods and has great application potential in clinical medical diagnoses such as sleep medicine and psychiatry.


Rhythm's Infographic Video

NHRI Digital Biomarkers Lab
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