Evaluating the Feasibility of Low-Cost, Contactless Consumer Sleep-Tracking Devices as Measurement Tools for Preliminary Sleep Research

Compared to polysomnography (PSG) and actigraphy, contactless consumer sleep-tracking devices (CCSTDs) are low-cost, user-friendly, and non-disruptive to sleep. This study evaluated the performance of two inexpensive, representative first-generation Chinese-made CCSTDs (the iSleep S200G and Sleep Dot B501) against PSG and actigraphy, using standardized validation protocols. The objective was to assess their feasibility as alternatives for large-scale, long-term preliminary research that does not rely on single-day high-precision sleep data. Eleven healthy young adults (mean age = 26.5 ± 4.8 years) participated in a two-night sleep laboratory study using four devices in parallel. Compared with PSG, the iSleep S200G exhibited no significant differences in TST and SE, while the Sleep Dot B501 showed no significant differences in TST, SE, SOL, and WASO. The intraclass correlation coefficient values and epoch-by-epoch agreement of the iSleep S200G and Sleep Dot B501 were as good as or better than those of actigraphy. Notably, the epoch-by-epoch agreement metric of both devices was not inferior to other consumer sleep-tracking devices already used for long-term, large-scale sleep monitoring. Therefore, even within budget constraints, first-generation CCSTDs can effectively meet the requirements for long-term, large-scale sleep monitoring without sleep stage detection. The results also provided data references for researchers using iteratively upgraded CCSTDs.