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Advances in numerical simulation have allowed the investigation of complex interaction of blood flow through elastic arteries which can be useful in demonstrating the disease progression and haemodynamics of cardiovascular diseases such as atherosclerosis. In the present study, patient is diagnosed with an occluded right Internal Carotid Artery (ICA) with partial stenosis at root of right External Carotid Artery (ECA) and partial stenosis at the root of left ICA. 3D patient specific carotid bifurcation is generated based on CT scan data using MIMICS-14.0 and numerical analysis is performed using FSI in ANSYS-14.5. The blood flow is assumed to be incompressible, homogenous and Newtonian, while artery wall is assumed to behave linearly elastic. The two-way sequentially coupled transient FSI analysis is performed using FSI solver for three pulse cycles and haemodynamic parameters such as flow pattern, Wall Shear Stress (WSS), pressure contours and arterial wall deformation are studied at the bifurcation and critical zones. The variation in flow behavior is investigated throughout the pulse and simulation results obtained reveals that there is a considerable increase in the flow behavior in partially stenosed carotid unlike occluded carotid. The investigation also demonstrates disturbed flow pattern especially at the bifurcation and stenosed zone elevating the haemodynamic variation during peak systole and later part of pulse cycle. The obtained results agree well with the clinical observation and demonstrate the potential of patient specific numerical studies in prognosis of disease progression and plaque rupture.

Atherosclerosis has been leading cause of deaths in several countries. Recent technical advances have allowed the investigation of stenotic flows and in understanding the implications with increased severity. Such studies shall provide detailed understanding of flow across stenosis and its progression. In the present study, a large artery representing segment of aorta is considered as test specimen. Experimental study is carried out by generating the pulsatile flow through pulsatile duplicator. Flow across normal and various severities of stenosis such as 25%, 50% and 75% are studied. Numerical simulation using CFD is also carried out in similar normal and stenosed models. A novel concept of using pulse duplicator to generate pulsatile waves and investigate the different stenosed models has been adopted. Results obtained experimentally and numerically are compared and agree well with that of clinical observations. This study demonstrates significant variation of haemodynamic in post-stenotic region with increased stenosis. Increased pulse pressure, phase lag is observed with increased severity. It is also observed that stenosis greater than 75% is significant as flow complexity is induced with considerable disturbance even in early and latter part of pulse cycle. Such study shall be useful in understanding the flow changes in stenosis and enhance clinical observation.

Gravity associated with postural changes has a strong bearing on haemodynamics of blood flow in arteries. Its effect on stenosed cases has not been widely investigated. In the present study, variation observed in blood flow during postural changes is investigated for different conditions like standing, sleeping and head-down position. A fluid structure interaction study is carried out for idealized normal and 75 % eccentric and concentric stenosed common carotid normal artery. The results clearly indicate the effects of altered gravity on flow conditions. It was found to be very significant during head-down position and demonstrated very high arterial blood pressure in stenosed common carotid when compared with normal carotid.

Atherosclerosis (stenosis) is a common cardiovascular disease in which the blood vessel restructures by narrowing, thickening and gets hardened due to the deposition of plaque. A detailed study of narrowing of arteries applying computational aspects which leads to better findings in order to know the underlying mechanics of development and progression of such diseases. Such kind of analysis can be a useful tool for the medical professionals to study the realistic physiological conditions. They can simulate and observe the blood flow in arteries. In the present study, a case of normal and stenosed carotid bifurcation is simulated. The models are generated in CATIA based on the clinical data obtained from a patient using Ultrasound Doppler. A transient FSI analysis considering Newtonian behavior is performed to compare the significance of High Blood Pressure (HBP) and Normal Blood Pressure (NBP) on carotid bifurcation. The FSI simulation is carried out for both HBP and NBP conditions for several pulse cycles on normal and stenosed models using ANSYS13.0 to demonstrate the changes in flow behavior at various sections of the model. The computed results agree well with clinical observations and available literature as seen in case of NBP.