The human ureters have not been thoroughly explored from the biomechanics perspective, despite the wealth of such data for other soft-tissue types. This study was motivated by the need to use relevant biomechanical data from human ureters and microstructure-based material formulations for simulations of ureteral peristalsis and stenting. Our starting choice was the four-fiber family model that has proven its validity as a descriptor of the multiaxial response of cardiovascular tissues. The degree of model complexity, required for rigorous fits to passive quasi-static pressure-diameter-force data at several axial stretches, was systematically investigated. Ureteral segments from sixteen human autopsy subjects were evaluated. A diagonal and axial family model allowed equally-good fits as the full model for all age groups and ureteral regions; considerably better than those allowed by the phenomenological Fung-type model whose root-mean-square error of fitting was three-fold greater. This reduced model mimicked the structure seen in histologic sections, namely plentiful diagonal collagen fibers in the lamina propria and axial fibers in the muscle and adventitia. The paucity of elastin fibers and mixed muscle orientation justified the use of isotropic muscle-dominated matrix with small neo-Hookean parameter values. The significantly thicker lamina propria in the lower than the upper ureter of young subjects (312±27 vs. 232±26 μm; mean±standard error) corroborated the significant regional differences in diagonal-fiber family parameter values. The significant muscle thickening with age (upper ureter: 373±48 vs. 527±67 μm; middle: 388±29 vs. 575±69 μm; lower: 440±21 vs. 602±71 μm) corroborated the significant age-related increase in axial-fiber family parameter values.

尽管从其他软组织类型获得了丰富的数据，但从生物力学的角度尚未对人类输尿管进行彻底的研究。这项研究的动机是需要使用来自人输尿管的相关生物力学数据和基于微结构的材料配方来模拟输尿管蠕动和支架置入。我们的起始选择是四纤维家族模型，该模型已证明其可作为心血管组织多轴反应的描述子。系统研究了在几个轴向拉伸条件下严格拟合被动准静态压力直径力数据所需的模型复杂程度。评估了来自16位人体解剖学受试者的输尿管节段。对角线和轴向家庭模型允许所有年龄组和输尿管区域的完全拟合为良好的拟合；明显优于现象学的Fung型模型允许的拟合均方根误差大三倍的模型。这种简化的模型模仿了在组织学切片中看到的结构，即固有层中的大量对角胶原纤维以及肌肉和外膜中的轴向纤维。弹性蛋白纤维的稀缺性和混合的肌肉取向证明使用各向同性的以肌肉为主的基质具有较小的新霍克参数值是合理的。在年轻受试者的下部比上部输尿管明显厚的固有层（312±27 vs. 232±26μm；平均值±标准误差）证实了对角纤维家族参数值的显着区域差异。随着年龄的增长，肌肉明显增厚（上输尿管：373±48 vs. 527±67μm;中：388±29 vs. 575±69μm;下：440±21 vs.