Current gastrointestinal (GI) treatments often require costly, invasive procedures with limited accuracy. Traditional monitoring methods, such as endoscopies and surface electrogastrograms, are constrained by the physical limitations of external tools and epicutaneous measurements, which are prone to noise and lack spatial precision. There is a growing need for more specific, temporally precise, and less invasive approaches to improve diagnostic and therapeutic outcomes. Ingestible devices present a promising solution by providing direct access to the GI tract and enteric nervous system. These miniaturized, biocompatible capsules can monitor key physiological signals such as pH, temperature, pressure, and biomolecular activity while preserving natural GI function. Integrated multi-electrode systems allow for improved electrogastrogram recordings, tissue impedance testing, and neuromodulation of enteric and autonomic systems. These features position ingestible devices as a transformative tool for improving the precision, efficiency, and patient experience of GI care.
Chronic vagus nerve neuromodulation of colonic motility using OIC pig model
Up to 80% of non-cancer patients on chronic opioids develop opioid-induced constipation (OIC), which worsens over time. Using a pig model of OIC induced by chronic loperamide, we evaluated whether cervical vagus nerve stimulation (CBVNS) could alleviate constipation.
We collaborate with Dr. Million Mulugeta’s team from UCLA medical school and created a OIC porcine model. These Yucatan minipigs were implanted with CBVN cuff electrodes and cecal cannulas, then administered daily loperamide. Colon motility was assessed via manometry. Acute CBVNS effects were tested in naïve-anesthetized pigs, while repeated CBVNS (R-CBVNS) was applied in OIC pigs. Manometry data from multiple colon segments were analyzed using motility index, frequency band power, and burst contraction features.
Acute CBVNS induced pan-colonic contractions. R-CBVNS improved motility in OIC pigs by enhancing proximal colon contraction frequency and modulating contraction rate, duration, and possibly secretory function, as indicated by increased stool water content.
Published Paper: https://doi.org/10.1111/nmo.13925 https://doi.org/10.1152/physiol.2024.39.S1.1242