Abstract

In the last years, there has been an interest in development of simulators to reproduce the mechanical properties of the human digestive system. Particularly, there have been some approaches in the development of esophagus simulators. Such simulators intend to replicate the peristaltic wave conditions, but the reported experiments are related to indirect measurements in which the use of a fluid is not reported. In this work, an X-ray technique for visualizing the flow of bolus through an artificial esophageal simulator (AES) is proposed. For that purpose, particles of barium sulfate were thoroughly mixed with baby food, in order to create a suspension used as bolus. Barium sulfate particles used in the present work are insoluble in water with non-regular forms, a size distribution from 20 to 80 nm, and a specific surface area ranging from 10 to 50 m²/g. The advantage of using barium sulfate is its high absorption of X-rays, which allows obtaining a good contrast in radiographies, so that the transport of the bolus along the esophagus simulator can be easily tracked. The results revealed the appearance of secondary flows on the wave sides, which displace as the wave contracts. This was verified with the flow fields, in which it was observed that the bolus flows mainly along the central part of the wave and a small volume tends to retract. This confirms that the flow is extensional as the bolus is stretched and compressed during the peristalsis.

Graphical abstract

中文翻译：

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X射线技术，用于可视化食道模拟器中的推注流量

摘要

在过去的几年中，人们对开发模拟器以重现人体消化系统的机械特性产生了兴趣。特别地，在食道模拟器的开发中存在一些方法。这种模拟器旨在复制蠕动波条件，但是所报告的实验与间接测量有关，在间接测量中未报告使用流体。在这项工作中，提出了一种X射线技术，用于可视化通过人工食管模拟器（AES）的推注流量。为此，将硫酸钡颗粒与婴儿食品充分混合，以制成用作浓注的悬浮液。本工作中使用的硫酸钡颗粒不溶于水，其形态不规则，尺寸分布为20至80 nm，² /克。使用硫酸钡的优点是其对X射线的高吸收性，从而可以在射线照相中获得良好的对比度，从而可以轻松地追踪弹药沿食道模拟器的运输。结果表明，在波浪侧出现了二次流动，并随着波浪的收缩而位移。这在流场中得到了证实，其中观察到弹丸主要沿波的中心部分流动，并且小体积倾向于回缩。这证实了当蠕动期间推注团被拉伸和压缩时血流是扩张的。

图形概要