The gut-brain axis, which is mediated via enteric and central neurohormonal signaling, is known to regulate a broad set of physiological functions from feeding to emotional behavior. Various pharmaceuticals and surgical interventions, such as motility agents and bariatric surgery, are used to modulate this axis. Such approaches, however, are associated with off-target effects or post-procedure recovery time and expose patients to substantial risks. Electrical stimulation has also been used to attempt to modulate the gut-brain axis with greater spatial and temporal resolution. Electrical stimulation of the gastrointestinal (GI) tract, however, has generally required invasive intervention for electrode placement on serosal tissue. Stimulating mucosal tissue remains challenging because of the presence of gastric and intestinal fluid, which can influence the effectiveness of local luminal stimulation. Here, we report the development of a bioinspired ingestible fluid-wicking capsule for active stimulation and hormone modulation (FLASH) capable of rapidly wicking fluid and locally stimulating mucosal tissue, resulting in systemic modulation of an orexigenic GI hormone. Drawing inspiration from Moloch horridus, the “thorny devil” lizard with water-wicking skin, we developed a capsule surface capable of displacing fluid. We characterized the stimulation parameters for modulation of various GI hormones in a porcine model and applied these parameters to an ingestible capsule system. FLASH can be orally administered to modulate GI hormones and is safely excreted with no adverse effects in porcine models. We anticipate that this device could be used to treat metabolic, GI, and neuropsychiatric disorders noninvasively with minimal off-target effects.

The mental and physiological stress experienced by surgeons during operations has been identified as an important human factor that impacts surgical performance and patient safety. It is crucial to objectively measure and quantify surgeons' stress via physiological signals in order to enhance the understanding of how stress contributes to surgical outcomes. Current clinical and consumer devices for monitoring bio signals are not well adapted for use in the operating room; therefore, we designed an unobtrusive system, that measures select signals that correlate with stress and stores the data for integration into a data processing pipeline. Herein, we present a proof-of-concept device that captures data from ECG, EMG, EDA, and IMU sensors and initial testing results. Clinical Relevance-Developing quantitative measures of stress in clinicians provides a means to understand, monitor and, potentially, mitigate situations that compromise their wellbeing and also affect the quality of patient care.