Towards patient-specific cardiovascular modeling system using the immersed boundary technique
Tóm tắt
Previous research shows that the flow dynamics in the left ventricle (LV) reveal important information about cardiac health. This information can be used in early diagnosis of patients with potential heart problems. The current study introduces a patient-specific cardiovascular-modelling system (CMS) which simulates the flow dynamics in the LV to facilitate physicians in early diagnosis of patients before heart failure. The proposed system will identify possible disease conditions and facilitates early diagnosis through hybrid computational fluid dynamics (CFD) simulation and time-resolved magnetic resonance imaging (4-D MRI). The simulation is based on the 3-D heart model, which can simultaneously compute fluid and elastic boundary motions using the immersed boundary method. At this preliminary stage, the 4-D MRI is used to provide an appropriate comparison. This allows flexible investigation of the flow features in the ventricles and their responses. The results simulate various flow rates and kinetic energy in the diastole and systole phases, demonstrating the feasibility of capturing some of the important characteristics of the heart during different phases. However, some discrepancies exist in the pulmonary vein and aorta flow rate between the numerical and experimental data. Further studies are essential to investigate and solve the remaining problems before using the data in clinical diagnostics. The results show that by using a simple reservoir pressure boundary condition (RPBC), we are able to capture some essential variations found in the clinical data. Our approach establishes a first-step framework of a practical patient-specific CMS, which comprises a 3-D CFD model (without involving actual hemodynamic data yet) to simulate the heart and the 4-D PC-MRI system. At this stage, the 4-D PC-MRI system is used for verification purpose rather than input. This brings us closer to our goal of developing a practical patient-specific CMS, which will be pursued next. We anticipate that in the future, this hybrid system can potentially identify possible disease conditions in LV through comprehensive analysis and facilitates physicians in early diagnosis of probable cardiac problems.
Tài liệu tham khảo
Verhey J, Bara C: Influence on fluid dynamics of coronary artery outlet angle variation in artificial aortic root prosthesis. BioMedical Engineering OnLine 2008, 7: 9. 10.1186/1475-925X-7-9
Verhey J, Nathan N: Feasibility of rapid and automated importation of 3D echocardiographic left ventricular (LV) geometry into a finite element (FEM) analysis model. BioMedical Engineering OnLine 2004, 3: 32. 10.1186/1475-925X-3-32
Bellhouse BJ: Fluid mechanics of a model mitral valve and left ventricle. Cardiovascular Research 1972, 6: 199–210. 10.1093/cvr/6.2.199
Bolzon G, Zovatto L, Pedrizzetti G: Birth of three-dimensionality in a pulsed jet through a circular orifice. Journal of Fluid Mechanics 2003, 493: 209–218.
Wieting DW, Stripling TE: Dynamics and fluid dynamics of the mitral valve. Recent Progress in Mitral Valve Disease 1984, 13–46.
Reul H, Talukder N, Muller EW: Fluid mechanics of the natural mitral valve. Journal of Biomechanics 1981, 14: 361–372. 10.1016/0021-9290(81)90046-4
McQueen DM, Peskin CS, Yellin EL: Fluid dynamics of the mitral valve: physiological aspects of a mathematical model. American Journal of Physiology 1982, 242: 1095–1110.
Fortini S, Querzoli G, Cenedese A, Marchetti M: The effect of mitral valve on left ventricular flow. Book The Effect of Mitral Valve on Left Ventricular Flow 2008.
Domenichini F, Pedrizzetti G, Baccani B: Three-dimensional filling flow into a model left ventricle. Journal of Fluid Mechanics 2005, 539: 179–198. 10.1017/S0022112005005550
Saber NR, Gosman AD, Wood NB, Kilner PJ, Charrier CL, Firmin DN: Computational flow modeling of the left ventricle based on in vivo MRI data: Initial experience. Annals of Biomedical Engineering 2001, 29: 275–283.
Kitajima HD, Sundareswaran KS, Teisseyre TZ, Astary GW, Parks WJ, Skrinjar O, Oshinski JN, Yoganathan AP: Comparison of particle image velocimetry and phase contrast MRI in a patient-specific extracardiac total cavopulmonary connection. Journal of Biomechanical Engineering 2008, 130: 041004–041014. 10.1115/1.2900725
Markl M, Harloff A, Bley TA, Zaitsev M, Jung B, Weigang E, Langer M, Hennig J, Frydrychowicz A: Time-resolved 3D MR velocity mapping at 3T: Improved navigator-gated assessment of vascular anatomy and blood flow. Journal of Magnetic Resonance Imaging 2007, 25: 824–831. 10.1002/jmri.20871
WHO: Cardiovascular Disease Programme: Integrated Management of Cardiovascular Risk . In Integrated Management of Cardiovascular Risk. World Health Organization; 2002.
McQueen DM, Peskin CS: A three-dimensional computer model of the human heart for studying cardiac fluid dynamics. Computer Graph 2000, 34: 56–60.
Mandinov L, Eberli FR, Seiler C, Hess OM: Diastolic heart failure. Cardiovascular Research 2000, 45: 813–825. 10.1016/S0008-6363(99)00399-5
Vasan RS, Levy D: Defining diastolic heart failure - A call for standardized diagnostic criteria. Circulation 2000, 101: 2118–2121.
Wetzel S, Meckel S, Frydrychowicz A, Bonati L, Radue EW, Scheffler K, Hennig J, Markl M: In vivo assessment and visualization of intracranial arterial hemodynamics with flow-sensitized 4D MR imaging at 3T. American Journal of Neuroradiology 2007, 28: 433–438.
Lai MC, Peskin CS: An immersed boundary method with formal second-order accuracy and reduced numerical viscosity. Journal of Computational Physics 2000, 160: 705–719. 10.1006/jcph.2000.6483
Tseng YH, Ferziger JH: A ghost-cell immersed boundary method for flow in complex geometry. Journal of Computational Physics 2003, 192: 593–623. 10.1016/j.jcp.2003.07.024
Udaykumar HS, Mittal R, Rampunggoon P, Khanna A: A sharp interface cartesian grid method for simulating flows with complex moving boundaries. Journal of Computational Physics 2001, 174: 345–380. 10.1006/jcph.2001.6916
Kovacs SJ, McQueen DM, Peskin CS: Modelling cardiac fluid dynamics and diastolic function. Philosophical Transactions of the Royal Society of London Series a-Mathematical Physical and Engineering Sciences 2001, 359: 1299–1314. 10.1098/rsta.2001.0832
Mittal R, Iaccarino G: Immersed boundary methods. Annual Review Fluid Mechanics 2005, 37: 239–261. 10.1146/annurev.fluid.37.061903.175743
McQueen DM, Peskin CS: A 3-dimensional computational method for blood-flow in the heart. II. contractile fibers. Journal of Computational Physics 1989, 82: 289–297. 10.1016/0021-9991(89)90050-8
Baccani B, Domenichini F, Pedrizzetti G, Tonti G: Fluid dynamics of the left ventricular filling in dilated cardiomyopathy. Journal of Biomechanics 2002, 35: 665–671. 10.1016/S0021-9290(02)00005-2
Domenichini F, Querzoli G, Cenedese A, Pedrizzetti G: Combined experimental and numerical analysis of the flow structure into the left ventricle. Journal of Biomechanics 2007, 40: 1988–1994. 10.1016/j.jbiomech.2006.09.024
Pierrakos O, Vlachos PP: The Effect of Vortex Formation on Left Ventricular Filling and Mitral Valve Efficiency. Journal of Biomechanical Engineering 2006, 128: 527–539. 10.1115/1.2205863
Kilner PJ, Yang G-Z, Wilkes AJ, Mohiaddin RH, Firmin DN, Yacoub MH: Asymmetric redirection of flow through the heart. Nature 2000, 404: 759–761. 10.1038/35008075
Pressures and the Heart: How Pressures Change in the Heart [http://www.childrensheartinstitute.org/educate/bloodprs/prchange.htm]