Skin-conformal electronics for wearable electrogastrography monitoring

Electrogastrography (EGG), a non-invasive method for measuring gastric myoelectrical activity, offers valuable insights into gastrointestinal motility and functional disorders such as gastroparesis and functional dyspepsia. Despite its diagnostic potential, the clinical adoption of EGG has been limited due to its reliance on rigid electrodes and bulky instrumentation, which leads to motion artifacts and poor signal quality, and ultimately reduces patient comfort and restricting data collection to short-duration, stationary settings. To address these limitations, we present FlexEGG, a skin-conformal, flexible electronic system engineered for high-fidelity EGG monitoring in both clinical and real-world environments. The device incorporates a soft, stretchable electrode array specifically designed for the abdominal surface, utilizing a hybrid stretchable conductor composed of conductive polymer, silver nanowires (AgNWs), and polyurethane elastomer, which leads to good skin contact, signal stability, and mechanical conformability. A custom low-noise analog front-end and digital signal processing pipeline enables reliable acquisition of low-frequency, low-amplitude gastric slow waves. Additionally, FlexEGG supports simultaneous electrocardiogram (ECG) measurement, potentially facilitating integrated gut-heart axis monitoring for broader physiological assessment. In this study, we describe the design, implementation, and validation of FlexEGG in multi-channel, long-duration EGG and ECG recordings. Our findings demonstrate its potential as a wearable, non-invasive tool for continuous gastrointestinal electrophysiology monitoring, enabling new opportunities for diagnosing and managing digestive disorders in everyday settings.