Realistic computer simulation of bolus flow during swallowing. (November 2020)

• Record Type: Journal Article
• Authors: Michiwaki, Yukihiro; Kamiya, Tetsu; Kikuchi, Takahiro; Toyama, Yoshio; Takai, Megumi; Hanyu, Keigo; Inoue, Motoki; Yahiro, Nobutaka; Koshizuka, Seiichi
• Is Part Of: Food hydrocolloids. Volume 108(2020)
• Publication Date: 2020-11
• Subjects: Swallowing simulation -- Aspiration -- Computer simulation -- Velocity -- Shear rate -- Viscosity -- Trajectory analysis; Hydrocolloids -- Periodicals; Food additives -- Periodicals; Colloïdes -- Périodiques; Aliments -- Additifs -- Périodiques; Colloids; Food additives; Periodicals; Electronic journals; 664.06
• DOI: 10.1016/j.foodhyd.2020.106040
• Languages: English
• ISSNs: 0268-005X

Abstract

Abstract: In this study, swallow simulation, Swallow Vision ®, was used to estimate the velocity, shear rate, and viscosity of food during swallowing. The subjects were a healthy young person and an elderly patient with aspiration. The test food was a Newtonian fluid (viscosity 2.5 mPa･ s) and a non-Newtonian fluid (viscosity 300 mPa･s at a shear rate of 50 [1/s]). A realistic numerical organ model was created based on Computed Tomography and Video-fluorography while swallowing the test food, and the bolus flow was analyzed using a numerical model whose validation was evaluated. Consequently, in the analysis of a model in which a healthy person swallowed the Newtonian fluid, the median velocity of the bolus flow changed in the range of 0.2–0.6 m/s, and there was a bimodal peak. The median shear rate ranged from 75 to 200 [1/s], and there were three peaks. In the swallowing of the non-Newtonian fluid, the flow velocity smoothly changed between 0.1 and 0.5 m/s, the shear rate varied between 50 and 100 [1/s], and the average of the median values during the entire swallowing process was 78 [1/s]. The trajectory analysis of the simulation model of the dysphagia patient demonstrated that the aspirated particles flowed faster than the non-aspirated particles. These results indicate that the numerical simulation based on medical images can analyze the bolus flow during swallowing, although there are still issues to be solved. Graphical abstract: Although the Newtonian fluid particles change their shear rate with time, the most frequent shear rate is approximately 100 [1/s]. Particle having the most frequent shear rate are quite a few about 100 in number. Consequently, the frequency distribution of the shear rate is constantly wide.In the non-Newtonian fluid, the frequency distribution has a sharp peak, approximately 75 [1/s] of shear rate, where more than 200 particles gather. Consequently, the frequency distribution spreads to an area narrower than that of the Newtonian fluid. Image 1 Highlights: Computer simulation estimated velocity, shear rate, and viscosity during swallowing. A Newtonian fluid velocity change had two peak values. A shear rate of a non-Newtonian fluid changed as the swallowing process proceeded.