Effect of wall elasticity on flow instability and wall shear stress of a patient-specific aneurysm model in middle cerebral artery

Abstract

The purpose of this study is to experimentally investigate the effect of wall deformation on flow behavior using a cerebral aneurysm model that considers patient-specific elastic deformation. Therefore, we measured by two-dimensional PIV and compared the time-series change of flow velocity and wall shear stress (WSS) under the condition of deformation of the model and the condition of less-deformation. The model used in this study was fabricated by the dipping method and is made of silicon. Imaging was performed using a high-speed camera and a UV laser. WSS was calculated from the wall-parallel velocity component at a distance of 0.25 mm from the aneurysm wall. As a result, turbulence of the flow velocity between cycles was observed under both less-deformation and deformed conditions, confirming the instability of the flow. In addition, the wall shear stress was smaller under deformation conditions than under less-deformation conditions, suggesting that the elastic deformation of the aneurysm wall reduces the wall shear stress.