Digital Twin of the Stomach: Applications to Digestive Disorders and Surgery Planning

Objective: The recent advances in computational power have enabled the use of in-silico approaches in studying physiological flows. In this study, we aim to develop a digital twin of the human stomach, StomachSim, to simulate gastric biomechanics in case of motility disorders and surgery. Methods: A physiologically realistic model of the stomach, including the antral motility, is synthesized based on in-vivo imaging data. The mixing and gastric emptying are simulated using computational fluid dynamics (CFD). Fundic accommodation, terminal antral contraction, and the phasic opening of the pyloric sphincter are incorporated into the model. The enlargement and disruption of pyloric sphincter due to pyloric intervention procedures or pyloric incompetence is also implemented. The influence of food properties (density and viscosity), motility disorders (50% reduced amplitude of antral contractions), and pyloric intervention procedures on gastric mixing, duodenogastric reflux, and solid-food trituration is investigated. The gastric emptying rate and the transpyloric pressure gradient predicted by the model were in good agreement with existing in-vivo measurements in the literature. Results: Reduced antral motility led to inefficient mixing of gastric contents and 49% lower pressure forces and 33% reduced hydrodynamic shear stresses on solid food particles. In cases with pyloric incompetence, reduced motility resulted in 66% lower duodenogastric reflux rate. When the gastric contents were of higher viscosity, the proximal stomach applied a higher pressure to achieve the same emptying rate resulting in reduced duodenogastric reflux. Higher viscosity also led to over 7 times increased shear stresses on solid food particles. Food density, on the other hand, primarily affected the transport of refluxed contents – when the gastric contents were lighter, duodenal contents entering the stomach settled along the lower antrum, and when the gastric contents were heavier, the reflux contents were transported proximally towards the esophagus. Conclusion: The digital-twin model presented in this study allows the exploration of a wide set of parameters related to gastric function. Our simulations quantify the consequences of motility disorders on gastric digestion and duodenogastric reflux. The model also reports detailed force characteristics of solid food particles undergoing trituration. StomachSim offers a novel and potentially effective modality for examining the effect of gastric conditions and gastric surgical procedures on gastric function. The authors acknowledge support from NSF award CBET 2019405. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.