In the cardiovascular diseased (CVD) conditions, it is essential to choose a suitable rheological model for capturing the correct physics behind the hemodynamic in the multiply afflicted diseased arterial network. This study investigates the effect of blood rheology on hemodynamics in a blood vessel with abdominal aortic aneurysm (AAA) and right internal iliac stenosis (RIIAS). A model with AAA and RIIAS is reconstructed from a human subject's computed tomography (CT) data. Localized mesh generation and pulsatile inflow condition are considered. Non-Newtonian models such as the Power-law, Carreau, Cross, and Herschel Berkley models are used in simulations. The outcome from a validated computational model is compared with the Newtonian model to identify the suitable model for dealing with pathological complications under consideration. The capabilities and significance of various rheological models are also examined via Wall Pressure (WP), Wall Shear Stress (WSS), velocity, Global non-Newtonian importance factor (IG), Vorticity Streamlines, and Swirling Strength. It is noted that during the entire cardiac cycle, the IG factor of the cross model is found to be relatively more significant. Power Law depicts larger IG factor during peak systole and early diastole. Also, the cross model depicts larger WSS, WPS, swirling strength distribution and vorticity during the peak systolic and diastolic phases It is noted that IG ∼0.02 is an appropriate non-Newtonian blood activity cut-off value in the descending abdominal artery having AAA and RIIAS. The critical important WSS values are in the range of 0-9 Pa which is stated in WSS contour plot.

Globally, high death rates due to heart failure are an essential topic in medical research. Cardiovascular disease is the leading cause of cardiac dysfunction and collapse, with high mortality and morbidity rates. Early diagnosis and prognosis of CVD will reduce the risk of cardiovascular conditions. It is essential to develop various tools that provide accurate, real-time insight into the heart's physiology, functionality, and cardiac events. Due to the dispersed nature of the information and the reported results, a comprehensive literature review is required because there is a shortage of data about the hemodynamics analysis of blood flow in the ventricular region. Therefore, reviewing the status of hemodynamics analysis of ventricle blood flow is the prime importance of this review article. This article reviews the numerous investigations conducted over the past 15 years to simulate ventricular blood flow using experimental and computational techniques on patient-specific models or idealized models with or without specific medical conditions. This article discusses the fundamentals of hemodynamic analysis, such as the geometry types of a particular cardiac phase, medical conditions, and medical imaging methods. Recent developments in hemodynamic analysis, such as AI, HPC, and digital twins, were also mentioned in this comprehensive review study. This review article concluded that improvements in medical image processing and data acquisition techniques are needed to obtain accurate information regarding the functioning of the heart. Our review of previous studies shows that blood flow simulation is developing into a proper medical tool for instant heart function diagnosis.

New imaging methods have enabled the detection of unruptured abdominal aortic aneurysms (AAA). It is necessary to develop appropriate mathematical models for rupture prediction to allow a proper patient treatment plan. To provide valid hemodynamic parameters, high-fidelity numerical models with patient-specific boundary conditions are needed. Researchers have pointed out in recent research articles and reviews that those morphological parameters, such as shape, dilation ratio, neck angle, common iliac bifurcation angle, and AAA type, consistently correlate with the rupture mechanism. However, it is unclear how morphological indicators affect hemodynamics-based computational fluid dynamics predictions. The present work investigates the influence of AAA shape on local and global hemodynamics parameters and rupture predictions. Five cases of magnetic resonance imaging scan-based data for patient-specific aortofemoral artery modeling are explored. The inflow conditions are patient-specific, and an open loop system has been considered to model all five cases. Hemodynamics parameters in pulsating conditions, such as wall shear stress (WSS), velocity contour, time average WSS (TAWSS), oscillatory shear index (OSI), vorticity, and streamlines, are computed and investigated. Both maximum dilation diameter and aneurysm neck angle are found to have substantial effects on local hemodynamics parameters. The magnitude of WSS, TAWSS, and OSI increases and decreases non-linearly with a change in maximum diameter during the cardiac process. Also, aneurysms with doubly titled and completely saccular shape show complex streamlines, low WSS, and high residence time in the sac area of the wall.

Due to the high degree of curvature of the coronary arteries, normal blood flow patterns are disrupted, making them susceptible sites for stenosis and atherosclerosis, leading to decrease in flow. Myocardial ischemia and infarction are the results of this reduced myocardial flow perfusion. Therefore, we conducted an extensive hemodynamic analysis on a patient suspected to have chest pain because of coronary artery disease in order to recognize the processes behind behaviors instigated by intricate geometry of the coronary artery. First, using coronary computed tomography angiography data, which were obtained from an ethically approved data provider, a patient-specific model was reconstructed. Open-circuit resemblance lumped parameter network coupled with zero-three dimensional (0D-3D) model was built to mimic coronary pressure and flow. Hemodynamic parameters such as the flow streamlines, time-average wall shear stress, oscillatory shear index, flow rate, and relative resilience time were investigated using computational fluid dynamics. It is critical for cardiac specialists to adequately care for their patients and provide corrective therapies at early onset of coronary problems caused by myocardial infarctions and demand coronary bypass surgery and stenting. The open loop modeling approach with lumped parameter-based physiologically and geometrically realistic outflow pressures will assist cardiologists in analyzing blood dynamics using the medically imaged coronary arteries of their patients and computing the magnitude of the hemodynamic parameters to provide them with a reliable assessment of the risk of coronary arterial disease for their patients.

The study of patient-specific human arterial flow dynamics is well known to face challenges like a) apt geometric modelling, b) bifurcation zone meshing, and c) capturing the hemodynamic prone to variations with multiple disease complications. Due to aneurysms and stenosis in the same arterial network, the blood flow dynamics get affected, which needs to be explored. This study develops a new protocol for accurate geometric modelling, bifurcation zone meshing and numerically investigates the arterial network with abdominal aortic aneurysms (AAA) and right internal iliac stenosis (RIIAS). A realistic arterial model is reconstructed from the computed tomography (CT) data of a human subject. To understand the combined effect of the aneurysm and aortoiliac occlusive diseases in a patient, an arterial network with AAA, RIIAS, multiple branches tapering, and curvature has been considered. Clinically significant pulsatile blood flow simulations have been carried out to trace the alteration in the flow dynamics with multiple pathological complications under consideration. The transient blood flow dynamics are investigated via wall shear stress, wall pressure, velocity contour, streamlines, vorticity, and swirling strength. During the systolic deceleration phase, the rhythmic nested rapid secondary oscillatory WSS, adverse pressure gradients, high WSS, and high WP bands are noticed. Also, the above studies will help researchers, clinicians, and doctors understand the influence of morphological changes on hemodynamics in cardiovascular studies.

Abdominal artery (AA) that originates from the heart, starting from the top of the left ventricle is the largest artery in the body and supplies oxygenated blood to all of the abdominal and pelvic organs and the legs. Atherosclerosis which is hardening and narrowing of arteries which result in an inadequate blood supply to vital organs. Anatomical complexity is accomplished using computerized axial tomography (CT) and magnetic resonance (MR) data. The purpose of this work is to create CAD model of abdominal artery. The redundant information such as noises are removed using Thresholding and region growing operation using medical image modelling by a software (MIMICS V19). Further the detail geometric features of AA are examined using software (3MATIC V19) to compare the dimensional details of the anatomical organ. The data is made compatible for computational fluid dynamics (CFD) analysis by converting stereo lithography (STL) data into volume mesh using finite element modeling (FEM) software. Thus the developed Finite element (FE) model can be used for understanding the velocity profile, drug delivery and complex problem associated with the blood flow.