Full-scale experiment to identify biomechanical parameters of the motor and evacuation functions of the stomach used in a mathematical model of food flow

The normal functioning of the stomach, duodenum and other parts of the digestive tract is important for the quality of food digestion. The advantage of mathematical models for studying digestive processes is the ability to predict the characteristics of food flow in the tract depending on various conditions (food properties, individual characteristics of the tract structure, the presence of functional disorders, etc.). However, to obtain adequate modeling results, it is necessary to determine the values of the model parameters with the required accuracy. Identification of parameters of mathematical models is carried out, as a rule, using experimental data. The purpose of this work was to identify the biomechanical parameters of the motor and evacuation functions of the stomach using a full-scale experiment for the subsequent use of the obtained values in a mathematical model. The article describes the procedure for conducting experimental studies to obtain individual parameters using ultrasound and biochemical blood tests. 10 experimental series of ultrasound studies were conducted after eating breakfast, which differed significantly in composition and caloric content, including both balanced diets (proteins, fats, carbohydrates) and those with a predominant content of fats, proteins or carbohydrates. The results provide data on gastric half-emptying time, the parameters of peristaltic waves in the antrum (amplitude, period, speed), the opening period and the diameter of the pyloric sphincter. Correlation coefficients characterizing the relationship between the composition of food taken and the parameters of the motor-evacuation function of the stomach are presented. The data obtained are supposed to be used in the future to construct the geometry of the individual shape of the stomach with time-varying parameters of shape and motility, and to conduct computational experiments with different food compositions. In subsequent publications, a detailed analysis of the relationships between the results of biochemical blood tests and the parameters of stomach motility and the composition of food taken is planned.