阐明结直肠残余应力的生理影响。
Toward Elucidating the Physiological Impacts of Residual Stresses in the Colorectum.
机构信息
Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269; Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269.
Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269.
出版信息
J Biomech Eng. 2022 Jan 1;144(1). doi: 10.1115/1.4051846.
Irritable bowel syndrome afflicts 10-20% of the global population, causing visceral pain with increased sensitivity to colorectal distension and normal bowel movements. Understanding and predicting these biomechanics will further advance our understanding of visceral pain and complement the existing literature on visceral neurophysiology. We recently performed a series of experiments at three longitudinal segments (colonic, intermediate, and rectal) of the distal 30 mm of colorectums of mice. We also established and fitted constitutive models addressing mechanical heterogeneity in both the through-thickness and longitudinal directions of the colorectum. Afferent nerve endings, strategically located within the submucosa, are likely nociceptors that detect concentrations of mechanical stresses to evoke the perception of pain from the viscera. In this study, we aim to: (1) establish and validate a method for incorporating residual stresses into models of colorectums, (2) predict the effects of residual stresses on the intratissue mechanics within the colorectum, and (3) establish intratissue distributions of stretches and stresses within the colorectum in vivo. To these ends we developed two-layered, composite finite element models of the colorectum based on our experimental evidence and validated our approaches against independent experimental data. We included layer- and segment-specific residual stretches/stresses in our simulations via the prestrain algorithm built into the finite element software febio. Our models and modeling approaches allow researchers to predict both organ and intratissue biomechanics of the colorectum and may facilitate better understanding of the underlying mechanical mechanisms of visceral pain.
肠易激综合征影响全球 10-20%的人口,导致内脏疼痛,对结肠扩张和正常肠蠕动的敏感性增加。了解和预测这些生物力学将进一步加深我们对内脏疼痛的理解,并补充现有的内脏神经生理学文献。我们最近在小鼠远端 30mm 的三个纵向节段(结肠、中间和直肠)的结肠进行了一系列实验。我们还建立并拟合了描述结肠的厚度和纵向方向的力学异质性的本构模型。位于黏膜下层的传入神经末梢很可能是痛觉感受器,它们检测机械应力的浓度,以引起内脏的疼痛感知。在这项研究中,我们的目的是:(1)建立和验证一种将残余应力纳入结肠模型的方法,(2)预测残余应力对结肠内组织力学的影响,(3)建立活体结肠内组织拉伸和应力的分布。为此,我们根据实验证据开发了两层复合有限元模型,并使用 febio 有限元软件中的预应变算法对我们的方法进行了验证。我们通过预应变算法在我们的模拟中包含了层和节特异性的残余拉伸/应力。我们的模型和建模方法可以让研究人员预测结肠的器官和组织内生物力学,并有助于更好地理解内脏疼痛的潜在机械机制。