De Menech Quentin, Osorio Salazar Andres, Bourgogne Quentin, Civet Yoan, Baldit Adrien, Perriard Yves
Integrated Actuators Laboratory (LAI), Ecole polytechnique fédérale de Lausanne (EPFL), Neuchâtel, 2002, Switzerland.
ENIM, Université de Lorraine, Metz, 57000, France.
Biomech Model Mechanobiol. 2025 Jun;24(3):1031-1042. doi: 10.1007/s10237-025-01951-w. Epub 2025 Apr 10.
Lower urinary tract symptoms (LUTS), particularly urinary incontinence (UI), represent a significant global health challenge, affecting millions of patients worldwide. The artificial urinary sphincter (AUS) remains one of the most effective intervention for severe UI, with its design relying on a detailed understanding of the urethral biomechanics. Given the ethical and logistical constraints of using human tissue, porcine urethras, which share anatomical and mechanical similarities with human urethras, are widely employed in preclinical studies. This study investigates the uniaxial mechanical characterization of porcine urethral tissue under controlled conditions. Fresh porcine urethral samples were subjected to uniaxial tensile testing along both the longitudinal and circumferential directions to characterize their anisotropic mechanical properties. Experimental results were compared with existing datasets to validate findings. Additionally, conventional hyperelastic models were assessed to fit experimental results, and a novel anisotropic constitutive model with physical parameters was developed. This fiber model, which incorporates fiber modulus, volume, and orientation, uses a single set of parameters to predict behavior in both directions. It demonstrated improved accuracy, reaching the performance of the Gasser-Ogden-Holzapfel (GOH) model, with root mean square errors (RMSEs) of 9.24% and 12.98% in the circumferential and longitudinal directions, respectively. In contrast, the Yeoh and Ogden models were unable to fit both directions using a single set of parameters, yielding RMSEs values exceeding 30%. With its enhanced physical relevance, the fiber model having a more physical meaning holds promise for applications in the biomechanical analysis of fiber-composed soft tissues.
下尿路症状（LUTS），尤其是尿失禁（UI），是一项重大的全球健康挑战，影响着全球数百万患者。人工尿道括约肌（AUS）仍然是治疗严重尿失禁最有效的干预措施之一，其设计依赖于对尿道生物力学的详细了解。鉴于使用人体组织存在伦理和后勤方面的限制，猪尿道在解剖学和力学上与人类尿道相似，因此在临床前研究中被广泛使用。本研究在可控条件下研究了猪尿道组织的单轴力学特性。对新鲜猪尿道样本沿纵向和周向进行单轴拉伸试验，以表征其各向异性力学性能。将实验结果与现有数据集进行比较以验证研究结果。此外，评估了传统的超弹性模型以拟合实验结果，并开发了一种具有物理参数的新型各向异性本构模型。这种纤维模型结合了纤维模量、体积和取向，使用一组参数来预测两个方向上的行为。它表现出更高的准确性，达到了Gasser-Ogden-Holzapfel（GOH）模型的性能，在周向和纵向方向上的均方根误差（RMSE）分别为9.24%和12.98%。相比之下，Yeoh和Ogden模型无法使用一组参数拟合两个方向，产生的RMSE值超过30%。具有增强的物理相关性且更具物理意义的纤维模型在纤维组成的软组织生物力学分析中的应用前景广阔。
