Simultaneous Stomach–Brain Electrophysiology for Assessment of Sleep Quality and Continuity

Stanford researchers have developed a non-invasive electrophysiological system and method that characterizes gastric–cortical coupling during human sleep using simultaneous electroencephalography (EEG) and electrogastrography (EGG), yielding an objective physiological marker of sleep quality that conventional polysomnography and heart-rate variability cannot capture.

Existing sleep monitoring technologies such as clinical polysomnography, consumer wearables, and HRV-based trackers can measure only cortical and cardiac signals, leaving the visceral contribution to restorative sleep unmeasured. Objective sleep metrics consequently remain weakly correlated with how rested individuals actually feel. The Stanford team addressed this gap by identifying, for the first time, an infraslow oscillation intrinsic to the gastric rhythm ( 0.02 Hz), together with signal-processing pipelines to extract it from surface EGG recordings.

Companion algorithms quantify multiscale stomach–brain interactions using phase–amplitude coupling, von Mises phase concentration, cross-correlation against EEG sigma-band power, slow-wave oscillations and spindles, and linear mixed-effects modeling. Variance in gastric infraslow amplitude uniquely explains subjective sleep quality beyond standard polysomnographic and cardiac measures, establishing the stomach as a peripheral oscillator in the regulation of sleep continuity and interoceptive stability. Because EGG signals can be acquired from leads compatible with DC-coupled EEG or ECG hardware, the technology can be deployed as a software and algorithm upgrade to existing platforms with minimal additional sensing.