Patel Bhavesh, Gizzi Alessio, Hashemi Javad, Awakeem Yousif, Gregersen Hans, Kassab Ghassan
California Medical Innovations Institute, 11107 Roselle St, San Diego, CA 92121, USA.
Department of Engineering, Campus Bio-Medico University of Rome, Via A. del Portillo 21, 00128 Rome, IT.
Mater Des. 2022 May;217. doi: 10.1016/j.matdes.2022.110576. Epub 2022 Mar 24.
The gastrointestinal (GI) tract is a continuous channel through the body that consists of the esophagus, the stomach, the small intestine, the large intestine, and the rectum. Its primary functions are to move the intake of food for digestion before storing and ultimately expulsion of feces. The mechanical behavior of GI tissues thus plays a crucial role for GI function in health and disease. The mechanical properties are characterized by a biomechanical constitutive model, which is a mathematical representation of the relation between load and deformation in a tissue. Hence, validated biomechanical constitutive models are essential to characterize and simulate the mechanical behavior of the GI tract. Here, a systematic review of these constitutive models is provided. This review is limited to studies where a model of the strain energy function is proposed to characterize the stress-strain relation of a GI tissue. Several needs are identified for more advanced modeling including: 1) Microstructural models that provide actual structure-function relations; 2) Validation of coupled electro-mechanical models accounting for active muscle contractions; 3) Human data to develop and validate models. The findings from this review provide guidelines for using existing constitutive models as well as perspective and directions for future studies.
胃肠道是贯穿人体的一个连续通道，由食管、胃、小肠、大肠和直肠组成。其主要功能是在储存并最终排出粪便之前，推动摄入的食物进行消化。因此，胃肠道组织的力学行为对健康和疾病状态下的胃肠道功能起着至关重要的作用。力学特性由生物力学本构模型来表征，该模型是组织中载荷与变形之间关系的数学表示。因此，经过验证的生物力学本构模型对于表征和模拟胃肠道的力学行为至关重要。在此，提供了对这些本构模型的系统综述。本综述仅限于那些提出应变能函数模型以表征胃肠道组织应力 - 应变关系的研究。确定了对更先进建模的若干需求，包括：1）提供实际结构 - 功能关系的微观结构模型；2）考虑主动肌肉收缩的耦合机电模型的验证；3）用于开发和验证模型的人体数据。本综述的结果为使用现有本构模型提供了指导方针，并为未来研究提供了视角和方向。
