Three-Dimension Stress and Strain Distributions Across Five-Layer Human Aortic Wall

Abstract

One of the implications of the structural changes in biomedical aspects is the change in stress and strain of the blood vessel. This research, therefore, aims to predict three-dimension stress and strain distributions across five-layer human aortic wall. In experiments, local aortic diameters can be obtained from cross-correlation technique on the ultrasound signal. Continuum mechanics is used as an approach to the results. The multilayer arterial wall is considered to be composed of five different layers. The three-dimensional effects are incorporated within the five-concentric axisymmetric layers while incorporating the nonlinear elastic characteristics under combined extension and inflation. Constitutive equation of fiber-reinforced material is employed for three major layers of intima, media and adventitia and constitutive equation of isotropic material is employed for other two layers of endothelium and internal elastic lamina. Relevant parameters for each layer are obtained by using nonlinear least square method fitted to in vivo experimental data on human aorta. Results from mechanical modeling, parameters could be precisely obtained with root of minimizes function of mean square error of pressures of 0.5631 kPa. Local stresses and strains distribution across deformed arterial wall could be illustrated and has been interpreted.