Sharif Digital Repository

It is proved that the endothelial (artery inner lumen cells) function is associated with cardiovascular risk factors. Among all the common non-invasive methods employed in the research setting for assessing endothelial function, flow-mediated dilation is the most widely used one. This technique measures endothelial function by inducing reactive hyperemia using temporary arterial occlusion and measuring the resultant relative increase in blood vessel diameter via ultrasound. In this paper, the limitations associated with the ultrasound technique are overcome by using the photoplethysmogram (PPG) signal recorded during FMD. The correctness of this approach is investigated by modeling the AC... 

In this study, the influence of vascular bed comprising terminal arterial branches on heat transfer in a liver tumor exposed to high intensity focused ultrasound (HIFU) is studied numerically. Also, the effect of vascular density on temperature distribution is investigated. A coupled set of acoustics, thermal, and fluid models is used to calculate the temperature distribution in the liver. The numerical model is established based on the Westervelt and bioheat equations along with the Navier-Stokes equations. Moreover, the acoustic streaming effect is included with Newtonian and non-Newtonian flow assumptions. It is found that in a vascular bed comprising terminal arterial branches, the...