Parameter Estimation of a Simple, Realistic Stochastic Model of Gastric Emptying of Pellets Under Fasting Conditions

Gastric emptying is the process by which the stomach releases food into the duodenum. The stomach exhibits regular churning contractions, occasionally coupled with peristaltic contractions and relaxation of the pyloric sphincter to produce an intermittent spurting of partially digested chyme into the duodenum. While most of the mathematical models of gastric emptying proposed in the literature are deterministic, it seems clear that the gastric emptying process itself is stochastic. Recently, our research group proposed a stochastic model to represent this irregular decrease in stomach content: the model closely mimics the inherently irregular behaviour of the gastric emptying mechanism.

In this study, a simulated maximum likelihood method was used to estimate the model parameters of the stochastic model for gastric emptying. An algorithm for partitioning a sample of subjects into subgroups with different gastric emptying rates was also presented. The proposed procedure for parameter estimation of the stochastic model is relatively simple to implement and can be used to analyse real patient data. The algorithm for identifying gastric emptying dynamics in subjects could provide useful information for further studies on the prediction of long-term energy balance.

Reference: Satiracoo P, De Gaetano A. Parameter estimation of a simple, realistic stochastic model of gastric emptying of pellets under fasting conditions. J Biol Syst 2021 Sep;29(3):561-76.