Viscoelastic Properties of Aorta From Oscillatory Pressure Tests

Aorta is the largest and most important artery in the body due to its role in conveying all of the oxygenated blood to smaller branches and ultimately to all of the organs in the body. Knowing its mechanical characteristics and material properties is a basic stage in almost all studies on aorta e.g. evaluating the effect of aging and disease, design and manufacturing of compatible stents and traumatic aortic rupture. Since blood vessels are non-homogeneous, non-linear viscoelastic materials and can experience large deformations, a unique formulation that can describe their mechanical behavior under various loading conditions has not been developed yet. Several previous studies looked into modeling of the blood vessels at large deformation, but the models developed did not include the time dependency of the material [1,2]. In this work, we characterized the material properties of aorta under biaxial oscillatory loading at large deformations taking into account its time dependency. A viscoelastic model was developed to describe the relationship between the inflation and pressure.