| Coronary atherosclerosis is a major cause of coronary heart disease and myocardial infarction,which not only has a negative impact on national health,but also imposes a heavy burden on the national economy.Investigating the mechanism of coronary atherosclerosis disease can help in the prevention and treatment of the disease.In this thesis,based on the CT image data of patients with coronary artery atherosclerosis,we used medical image processing software Mimics,reverse engineering software Geomagic studio,and modeling software Solidworks to extract,smooth,and recreate the 3D geometric structure of the patient’s left coronary artery,and finally realize the 3D modeling of the left coronary artery.Based on the fluid structure interaction method,we studied the hemodynamics of left coronary atherosclerosis,analyzed the relationship between the process of coronary atherosclerosis disease generation and blood flow state,and explored the influence of different factors on coronary atherosclerosis using numerical simulation results.The effect of left coronary artery morphology was investigated: the effect of three factors on coronary atherosclerosis based on Taguchi’s method: left main coronary artery diameter,angle of bifurcation of the left circumflex branch and left anterior descending branch,and left anterior descending artery length,with OSI as a response index.Data were rated using signal to noise ratio analysis,extreme variance analysis,analysis of variance,regression analysis and residual analysis.The results showed that the effects of all three factors on OSI values were significant,from strong to weak,in the order of anterior descending branch anterior length,bifurcation angle of left circumflex branch and left anterior descending branch,and main coronary artery diameter.A prediction model for the effect of the three factors on OSI values was established by regression analysis.The effect of plaque circumferential distribution was investigated: the role of plaque circumferential distribution on blood flow was analyzed when the degree of coronary atherosclerotic plaque stenosis was the same.Four 3D models with different plaque circumferential locations were constructed and numerically simulated under the same conditions,and the results showed that the plaque circumferential distribution had little effect on the risk of plaque rupture,had a greater effect on blood flow and flow velocity in each branch downstream of the plaque,and had a significant effect on WSS.The risk of further development of coronary atherosclerosis was greatest when the plaque was located on the side away from the left circumflex branch,followed by plaque on the side away from the heart and plaque on the side close to the heart,and the least risk was on the side of the plaque near the left circumflex branch.The effect of hypertension on the progression of coronary atherosclerosis was investigated: four numerical models with different pressures were constructed to simulate the effect of different severity of hypertension on coronary atherosclerosis.The findings suggest that hypertension expands atherosclerosis-inducing areas,which in turn promotes the development of coronary atherosclerosis.This paper concludes from the above studies that: three factors,anterior descending branch anterior length,angle of bifurcation between the left circumflex and left anterior descending branches,and diameter of the main coronary artery,have significant effects on the progression of coronary atherosclerosis;the risk of atherosclerosis development varies with the circumferential position of the plaque within the left coronary artery;and elevated blood pressure in hypertensive patients promotes the development of coronary atherosclerosis.The study findings can help clinicians develop treatment plans. |
