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 of sleep. This study evaluates the performance of two inexpensive and representative first-generation Chinese-made CCSTDs—the iSleep S200G and Sleep Dot B501—compared with PSG and actigraphy using standardized validation protocols. The objective is to assess their feasibility as alternatives for large-scale, long-term preliminary research that do 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. The iSleep S200G exhibited no significant differences compared to PSG 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 iSleep S200G and Sleep Dot B501 were comparable to or superior to actigraphy. Notably, the Epoch-by-epoch agreement of both devices are non-inferior to consumer-grade sleep 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 stages detection. The results also provide data references for researchers adopting the iterative upgrade of CCSTDs.