Computer simulations of the hydrodynamics within the human gastrointestinal tract

这个博士项目的目标是开发一个计算机模型来描述粘性流体在结肠中的运动，这种运动是由各种运动事件引起的，例如混合（分割）和周期性收缩的灵活的墙壁问题。就药物吸收而言，结肠是研究最少的胃肠道区域，但对于口服制剂，结肠吸收代表了增加给药间隔的唯一真实的机会。然而，结肠吸收的程度和重要性很难预测，因为通过时间和渗透性变化很大;缺乏对流体流动的了解以及缺乏体内预测模型。方法。如今，数学建模和计算机模拟已成为医学研究的重要工具。计算机模拟模型越来越多地支持传统的体内和体外模型，以更好地理解许多生理和生物力学现象。此外，机理模型（PBPK）对药物开发做出了重大贡献，并要求其成为制药行业向监管机构（FDA）应用的一部分。在这个项目中，成功的候选人将建立一个基于称为离散多物理的新建模技术的结肠计算机模型[1]。该模型将用于研究结肠中的流体动力学和传质，从而更深入地了解药物在该器官中的吸收机制。

The objective.This PhD project will develop a computer model that describes the motion of viscous fluids in the colon caused by various motility events such as mixing (segmentation) and periodic contractions of its flexible walls (peristalsis).The problem.The colon is the least researched GI region in terms of drug absorption, yet for orally administered formulations, colonic absorption represents the only real opportunity to increase the interval between doses. The extent and importance of colonic absorption are, however, difficult to predict due to the highly variable transit time and permeability; lack of knowledge on fluid flow and a lack of in vivo predictive models. The approach. Nowadays, mathematical modelling and computer simulations have become a valuable investigation tool in medicine. In-silico models are increasingly supporting traditional in-vivo and in-vitro models to achieve a better understanding of many physiological and biomechanics phenomena. In addition, mechanistic models (PBPK) have significantly contributed on drug development and it's required to be part of applications of pharmaceutical industries to regulatory bodies (FDA). During this project, the successful candidate will set up a computer model of the colon based on a novel modelling technique called Discrete Multi-Physics [1]. The model will be used to investigate the hydrodynamics and the mass transfer in the colon gaining a deeper understanding of the mechanisms of drug absorption in this organ.