Experimental analysis on hemodynamic characteristics in a deformable stenoses

摘要

Atherosclerotic plaques are often built up at certain blood vessels, and they form a stenosis.The plaques may rupture with a high risk of clinical events, such as myocardial infarction and stroke.However, the exact mechanism of the rupture has not been fully understood yet.The existing diagnostic methods have technical limitation in accurate identification of vulnerable stenosis.The vulnerable stenosis ruptures when a local stress exceeds a certain threshold value.Mechanical forces related with flow structure have been investigated by analyzing blood flows in the stenotic vessel.However, the stenosis was assumed to maintain its shape under pulsatile flow conditions in most previous studies.Many in vivo clinical diagnoses reported the presence of deformable stenosis and its rupture.In this study, deformable stenosis models were fabricated to mimic more realistic vulnerable stenoses.The cross-section of the models has an asymmetrical plaque, a circular lumen, and a crescent-shaped lipid pool.Two similar models having different thickness (60,500μm) were tested to investigate the effect of cap thickness.The hemodynamic characteristics of blood flows around the deformable stenosis models were investigated experimentally using a pathline flow visualization.Particle Image Velocimetry (PIV) analysis will be conducted to analyze flow characteristics.This study would be helpful to understand the pathology of plaque rupture and to develop a new diagnostic means for accurate diagnosis of vulnerable stnoses.