Institut de Mécanique des Fluides et des Solides, UdS-CNRS, University of Strasbourg, 2 Rue Boussingault, Strasbourg 67000, France.
J Biomech. 2011 Jun 3;44(9):1678-83. doi: 10.1016/j.jbiomech.2011.03.029. Epub 2011 Apr 9.
Understanding the mechanical properties of human liver is the most critical aspect of numerical modeling for medical applications and impact biomechanics. Many researchers work on identifying mechanical properties of the liver both in vivo and in vitro considering the high liver injury percentage in abdominal trauma and for easy detection of fatal liver diseases such as viral hepatitis, cirrhosis, etc. This study is performed to characterize mechanical properties of individual parts of the liver, namely Glisson's capsule and hepatic veins, as these parts are rarely characterized separately. The long term objective of this study is to develop a realistic liver model by characterizing individual parts and later integrating them. In vitro uniaxial quasi-static tensile tests are done on fresh unfrozen porcine hepatic parts for large deformations at the rate of 0.1mm/s with a Bose Electroforce 3200 biomaterials test instrument. Results show that mean values of small strain and large strain elastic moduli are 8.22 ± 3.42 and 48.15 ± 4.5 MPa for Glisson's capsule (30 samples) and 0.62 ± 0.41 and 2.81 ± 2.23 MPa for veins (20 samples), respectively, and are found to be in good agreement with data in the literature. Finally, a non-linear hyper-elastic constitutive law is proposed for the two separate liver constituents under study.
了解人体肝脏的力学特性是医学应用和冲击生物力学数值建模最关键的方面。许多研究人员致力于在体内和体外识别肝脏的力学特性，考虑到腹部创伤中肝脏损伤的高百分比，以及便于检测病毒性肝炎、肝硬化等致命肝脏疾病。本研究旨在对肝脏的各个部位（即 Glisson 囊和肝静脉）的力学特性进行特征化，因为这些部位很少单独进行特征化。本研究的长期目标是通过对各个部分进行特征化，然后将它们整合在一起，开发出一个现实的肝脏模型。使用 Bose Electroforce 3200 生物材料测试仪器，以 0.1mm/s 的速率对新鲜未冷冻的猪肝组织进行体外单轴准静态拉伸试验，以实现大变形。结果表明，Glisson 囊（30 个样本）的小应变和大应变弹性模量的平均值分别为 8.22±3.42 和 48.15±4.5MPa，而静脉（20 个样本）的小应变和大应变弹性模量的平均值分别为 0.62±0.41 和 2.81±2.23MPa，与文献中的数据吻合良好。最后，针对所研究的两种不同的肝脏成分，提出了一种非线性超弹性本构定律。
