Modelling and Simulation in Biomedical Research

Brief Overview Of The Field

The search for the best way of understanding and then explaining motion in general and flow in particular has preoccupied the human mind for centuries. The focus of our research program is blood flow. In itself and in the context of the whole human body function, blood flow is one of the hidden-to-the-naked-eye phenomena, difficult to visualize, expose and explain. The need for a thorough examination lies in the tight connection between arteries, their vessel walls and the blood flowing through. The goal of our research is elucidating the role of fluid mechanic forces in cardiovascular disease and treatment. Arteries adjust their caliber to maintain the level of wall shear stress, the frictional force exerted by flowing blood against the vessel wall. The endothelial cells that line the wall, cells which also respond to and express various molecular factors, mediate this behaviour. Atherosclerosis (fatty deposits in the artery wall) and aneurysms (ballooning of the artery wall) tend to develop at sites of complicated blood flow patterns. Their rupture, the event that precipitates many heart attacks and strokes, is determined in large part by the mechanical forces exerted on them. The success of vascular surgeries or minimally invasive procedures depends on the skill of the surgeon or interventionalist as much as it depends on the type of intervention or the design of the medical device chosen. The right strategy is crucial in avoiding the induction of further blood-flow-induced complications. With the discovery of the connection between flow patterns and circulatory system disease, the value and significance of computational fluid dynamics (CFD) was acknowledged, and CFD experts have been since involved in the designing and developing of the techniques and devices used in various vascular interventions (such as bypass grafts, stents or coils).

The need for exploring unseen areas of the body is not new: it has been preoccupying anatomists and clinicians since the dawn of medical science, but became the driving force behind perfecting the medical visualization techniques and technology over the last century. It all appears to have begun with Roentgen’s discovery of X-rays, which initiated the modern age of medical imaging and set in motion a series of developments and applications that lead to previously unthinkable discoveries in the field. The initial accidental discovery was almost immediately followed by well-designed experiments that helped calibrate and adjust the apparatus and, subsequently, angiography was born from the idea of replacing blood with a radio-opaque dye.¹