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Koivumäki JT, Hoffman J, Maleckar MM, Einevoll GT, Sundnes J. Computational cardiac physiology for new modelers: Origins, foundations, and future. Acta Physiol (Oxf) 2022; 236:e13865. [PMID: 35959512 DOI: 10.1111/apha.13865] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 01/29/2023]
Abstract
Mathematical models of the cardiovascular system have come a long way since they were first introduced in the early 19th century. Driven by a rapid development of experimental techniques, numerical methods, and computer hardware, detailed models that describe physical scales from the molecular level up to organs and organ systems have been derived and used for physiological research. Mathematical and computational models can be seen as condensed and quantitative formulations of extensive physiological knowledge and are used for formulating and testing hypotheses, interpreting and directing experimental research, and have contributed substantially to our understanding of cardiovascular physiology. However, in spite of the strengths of mathematics to precisely describe complex relationships and the obvious need for the mathematical and computational models to be informed by experimental data, there still exist considerable barriers between experimental and computational physiological research. In this review, we present a historical overview of the development of mathematical and computational models in cardiovascular physiology, including the current state of the art. We further argue why a tighter integration is needed between experimental and computational scientists in physiology, and point out important obstacles and challenges that must be overcome in order to fully realize the synergy of experimental and computational physiological research.
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Affiliation(s)
- Jussi T Koivumäki
- Faculty of Medicine and Health Technology, and Centre of Excellence in Body-on-Chip Research, Tampere University, Tampere, Finland
| | - Johan Hoffman
- Division of Computational Science and Technology, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Mary M Maleckar
- Computational Physiology Department, Simula Research Laboratory, Oslo, Norway
| | - Gaute T Einevoll
- Centre for Integrative Neuroplasticity, University of Oslo, Oslo, Norway.,Department of Physics, University of Oslo, Oslo, Norway.,Department of Physics, Norwegian University of Life Sciences, Ås, Norway
| | - Joakim Sundnes
- Computational Physiology Department, Simula Research Laboratory, Oslo, Norway
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2
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Goubergrits L, Vellguth K, Obermeier L, Schlief A, Tautz L, Bruening J, Lamecker H, Szengel A, Nemchyna O, Knosalla C, Kuehne T, Solowjowa N. CT-Based Analysis of Left Ventricular Hemodynamics Using Statistical Shape Modeling and Computational Fluid Dynamics. Front Cardiovasc Med 2022; 9:901902. [PMID: 35865389 PMCID: PMC9294248 DOI: 10.3389/fcvm.2022.901902] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/07/2022] [Indexed: 11/17/2022] Open
Abstract
Background Cardiac computed tomography (CCT) based computational fluid dynamics (CFD) allows to assess intracardiac flow features, which are hypothesized as an early predictor for heart diseases and may support treatment decisions. However, the understanding of intracardiac flow is challenging due to high variability in heart shapes and contractility. Using statistical shape modeling (SSM) in combination with CFD facilitates an intracardiac flow analysis. The aim of this study is to prove the usability of a new approach to describe various cohorts. Materials and Methods CCT data of 125 patients (mean age: 60.6 ± 10.0 years, 16.8% woman) were used to generate SSMs representing aneurysmatic and non-aneurysmatic left ventricles (LVs). Using SSMs, seven group-averaged LV shapes and contraction fields were generated: four representing patients with and without aneurysms and with mild or severe mitral regurgitation (MR), and three distinguishing aneurysmatic patients with true, intermediate aneurysms, and globally hypokinetic LVs. End-diastolic LV volumes of the groups varied between 258 and 347 ml, whereas ejection fractions varied between 21 and 26%. MR degrees varied from 1.0 to 2.5. Prescribed motion CFD was used to simulate intracardiac flow, which was analyzed regarding large-scale flow features, kinetic energy, washout, and pressure gradients. Results SSMs of aneurysmatic and non-aneurysmatic LVs were generated. Differences in shapes and contractility were found in the first three shape modes. Ninety percent of the cumulative shape variance is described with approximately 30 modes. A comparison of hemodynamics between all groups found shape-, contractility- and MR-dependent differences. Disturbed blood washout in the apex region was found in the aneurysmatic cases. With increasing MR, the diastolic jet becomes less coherent, whereas energy dissipation increases by decreasing kinetic energy. The poorest blood washout was found for the globally hypokinetic group, whereas the weakest blood washout in the apex region was found for the true aneurysm group. Conclusion The proposed CCT-based analysis of hemodynamics combining CFD with SSM seems promising to facilitate the analysis of intracardiac flow, thus increasing the value of CCT for diagnostic and treatment decisions. With further enhancement of the computational approach, the methodology has the potential to be embedded in clinical routine workflows and support clinicians.
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Affiliation(s)
- Leonid Goubergrits
- Institute of Computer-Assisted Cardiovascular Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Einstein Center Digital Future, Berlin, Germany
| | - Katharina Vellguth
- Institute of Computer-Assisted Cardiovascular Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Lukas Obermeier
- Institute of Computer-Assisted Cardiovascular Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Adriano Schlief
- Institute of Computer-Assisted Cardiovascular Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Lennart Tautz
- Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Jan Bruening
- Institute of Computer-Assisted Cardiovascular Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | | | - Olena Nemchyna
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Christoph Knosalla
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
- German Centre for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Titus Kuehne
- Institute of Computer-Assisted Cardiovascular Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
- German Centre for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany
| | - Natalia Solowjowa
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
- *Correspondence: Natalia Solowjowa
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Obermeier L, Vellguth K, Schlief A, Tautz L, Bruening J, Knosalla C, Kuehne T, Solowjowa N, Goubergrits L. CT-Based Simulation of Left Ventricular Hemodynamics: A Pilot Study in Mitral Regurgitation and Left Ventricle Aneurysm Patients. Front Cardiovasc Med 2022; 9:828556. [PMID: 35391837 PMCID: PMC8980692 DOI: 10.3389/fcvm.2022.828556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/03/2022] [Indexed: 12/30/2022] Open
Abstract
BackgroundCardiac CT (CCT) is well suited for a detailed analysis of heart structures due to its high spatial resolution, but in contrast to MRI and echocardiography, CCT does not allow an assessment of intracardiac flow. Computational fluid dynamics (CFD) can complement this shortcoming. It enables the computation of hemodynamics at a high spatio-temporal resolution based on medical images. The aim of this proposed study is to establish a CCT-based CFD methodology for the analysis of left ventricle (LV) hemodynamics and to assess the usability of the computational framework for clinical practice.Materials and MethodsThe methodology is demonstrated by means of four cases selected from a cohort of 125 multiphase CCT examinations of heart failure patients. These cases represent subcohorts of patients with and without LV aneurysm and with severe and no mitral regurgitation (MR). All selected LVs are dilated and characterized by a reduced ejection fraction (EF). End-diastolic and end-systolic image data was used to reconstruct LV geometries with 2D valves as well as the ventricular movement. The intraventricular hemodynamics were computed with a prescribed-motion CFD approach and evaluated in terms of large-scale flow patterns, energetic behavior, and intraventricular washout.ResultsIn the MR patients, a disrupted E-wave jet, a fragmentary diastolic vortex formation and an increased specific energy dissipation in systole are observed. In all cases, regions with an impaired washout are visible. The results furthermore indicate that considering several cycles might provide a more detailed view of the washout process. The pre-processing times and computational expenses are in reach of clinical feasibility.ConclusionThe proposed CCT-based CFD method allows to compute patient-specific intraventricular hemodynamics and thus complements the informative value of CCT. The method can be applied to any CCT data of common quality and represents a fair balance between model accuracy and overall expenses. With further model enhancements, the computational framework has the potential to be embedded in clinical routine workflows, to support clinical decision making and treatment planning.
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Affiliation(s)
- Lukas Obermeier
- Institute of Computer-Assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
- *Correspondence: Lukas Obermeier
| | - Katharina Vellguth
- Institute of Computer-Assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Adriano Schlief
- Institute of Computer-Assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Lennart Tautz
- Institute of Computer-Assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Jan Bruening
- Institute of Computer-Assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Christoph Knosalla
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt - Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Titus Kuehne
- Institute of Computer-Assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
- Department of Congenital Heart Disease, German Heart Center Berlin, Berlin, Germany
| | - Natalia Solowjowa
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Leonid Goubergrits
- Institute of Computer-Assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Einstein Center Digital Future, Berlin, Germany
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4
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Fatehi Hassanabad A, Wiebe K, Ali IS. Clinical and hemodynamic outcomes of the Dor procedure in adults with ischemic cardiomyopathy. J Card Surg 2021; 36:4345-4366. [PMID: 34494297 DOI: 10.1111/jocs.15968] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/07/2021] [Accepted: 07/26/2021] [Indexed: 11/30/2022]
Abstract
Ischemic cardiomyopathy continues to be a major contributor to congestive heart failure, which places a significant burden on our healthcare system. Improving medications and different coronary revascularization strategies are the mainstays in the management of ischemic cardiomyopathy. Although medications and mechanical circulatory support are playing an ever-increasing role, cardiac transplantation remains the gold standard for treating advanced heart failure. Given the small number of available and suitable donor hearts, transplantation is limited for the majority of patients. Surgical ventricular restoration has repeatedly been suggested as a viable alternative in managing heart failure in select patients, as it is believed that surgically returning the ventricle to its original dimensions is possible and associated with favorable outcomes. The purpose of this manuscript is to comprehensively review the current literature on various surgical strategies for ventricular restoration. We also contextualize the published data with respect to ventricular function, volume, structure, arrhythmias, mitral regurgitation, and clinical outcomes.
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Affiliation(s)
- Ali Fatehi Hassanabad
- Section of Cardiac Surgery, Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Kiana Wiebe
- Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Imtiaz S Ali
- Section of Cardiac Surgery, Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Baiocchi M, Barsoum S, Khodaei S, de la Torre Hernandez JM, Valentino SE, Dunford EC, MacDonald MJ, Keshavarz-Motamed Z. Effects of Choice of Medical Imaging Modalities on a Non-invasive Diagnostic and Monitoring Computational Framework for Patients With Complex Valvular, Vascular, and Ventricular Diseases Who Undergo Transcatheter Aortic Valve Replacement. Front Bioeng Biotechnol 2021; 9:643453. [PMID: 34307316 PMCID: PMC8297508 DOI: 10.3389/fbioe.2021.643453] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/19/2021] [Indexed: 11/13/2022] Open
Abstract
Due to the high individual differences in the anatomy and pathophysiology of patients, planning individualized treatment requires patient-specific diagnosis. Indeed, hemodynamic quantification can be immensely valuable for accurate diagnosis, however, we still lack precise diagnostic methods for numerous cardiovascular diseases including complex (and mixed) valvular, vascular, and ventricular interactions (C3VI) which is a complicated situation made even more challenging in the face of other cardiovascular pathologies. Transcatheter aortic valve replacement (TAVR) is a new less invasive intervention and is a growing alternative for patients with aortic stenosis. In a recent paper, we developed a non-invasive and Doppler-based diagnostic and monitoring computational mechanics framework for C3VI, called C3VI-DE that uses input parameters measured reliably using Doppler echocardiography. In the present work, we have developed another computational-mechanics framework for C3VI (called C3VI-CT). C3VI-CT uses the same lumped-parameter model core as C3VI-DE but its input parameters are measured using computed tomography and a sphygmomanometer. Both frameworks can quantify: (1) global hemodynamics (metrics of cardiac function); (2) local hemodynamics (metrics of circulatory function). We compared accuracy of the results obtained using C3VI-DE and C3VI-CT against catheterization data (gold standard) using a C3VI dataset (N = 49) for patients with C3VI who undergo TAVR in both pre and post-TAVR with a high variability. Because of the dataset variability and the broad range of diseases that it covers, it enables determining which framework can yield the most accurate results. In contrast with C3VI-CT, C3VI-DE tracks both the cardiac and vascular status and is in great agreement with cardiac catheter data.
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Affiliation(s)
- Melissa Baiocchi
- Department of Mechanical Engineering, McMaster University, Hamilton, ON, Canada
| | - Shirley Barsoum
- Department of Mechanical Engineering, McMaster University, Hamilton, ON, Canada
| | - Seyedvahid Khodaei
- Department of Mechanical Engineering, McMaster University, Hamilton, ON, Canada
| | | | | | - Emily C Dunford
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | | | - Zahra Keshavarz-Motamed
- Department of Mechanical Engineering, McMaster University, Hamilton, ON, Canada.,School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada.,School of Computational Science and Engineering, McMaster University, Hamilton, ON, Canada
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6
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Chen P, van Sloun RJG, Turco S, Wijkstra H, Filomena D, Agati L, Houthuizen P, Mischi M. Blood flow patterns estimation in the left ventricle with low-rate 2D and 3D dynamic contrast-enhanced ultrasound. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 198:105810. [PMID: 33218707 DOI: 10.1016/j.cmpb.2020.105810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 10/14/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND OBJECTIVE Left ventricle (LV) dysfunction always occurs at early heart-failure stages, producing variations in the LV flow patterns. Cardiac diagnostics may therefore benefit from flow-pattern analysis. Several visualization tools have been proposed that require ultrafast ultrasound acquisitions. However, ultrafast ultrasound is not standard in clinical scanners. Meanwhile techniques that can handle low frame rates are still lacking. As a result, the clinical translation of these techniques remains limited, especially for 3D acquisitions where the volume rates are intrinsically low. METHODS To overcome these limitations, we propose a novel technique for the estimation of LV blood velocity and relative-pressure fields from dynamic contrast-enhanced ultrasound (DCE-US) at low frame rates. Different from other methods, our method is based on the time-delays between time-intensity curves measured at neighbor pixels in the DCE-US loops. Using Navier-Stokes equation, we regularize the obtained velocity fields and derive relative-pressure estimates. Blood flow patterns were characterized with regard to their vorticity, relative-pressure changes (dp/dt) in the LV outflow tract, and viscous energy loss, as these reflect the ejection efficiency. RESULTS We evaluated the proposed method on 18 patients (9 responders and 9 non-responders) who underwent cardiac resynchronization therapy (CRT). After CRT, the responder group evidenced a significant (p<0.05) increase in vorticity and peak dp/dt, and a non-significant decrease in viscous energy loss. No significant difference was found in the non-responder group. Relative feature variation before and after CRT evidenced a significant difference (p<0.05) between responders and non-responders for vorticity and peak dp/dt. Finally, the method feasibility is also shown with 3D DCE-US. CONCLUSIONS Using the proposed method, adequate visualization and quantification of blood flow patterns are successfully enabled based on low-rate DCE-US of the LV, facilitating the clinical adoption of the method using standard ultrasound scanners. The clinical value of the method in the context of CRT is also shown.
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Affiliation(s)
- Peiran Chen
- Department of Electrical Engineering, Eindhoven University of Technology, Netherlands.
| | - Ruud J G van Sloun
- Department of Electrical Engineering, Eindhoven University of Technology, Netherlands
| | - Simona Turco
- Department of Electrical Engineering, Eindhoven University of Technology, Netherlands
| | - Hessel Wijkstra
- Department of Electrical Engineering, Eindhoven University of Technology, Netherlands; Department of Urology, Amsterdam University Medical Centers, Netherlands
| | - Domenico Filomena
- Department of Cardiovascular, Respiratory, Nephrological, Aenesthesiological and Geriatric Sciences, Sapienza University of Rome, Italy
| | - Luciano Agati
- Department of Cardiovascular, Respiratory, Nephrological, Aenesthesiological and Geriatric Sciences, Sapienza University of Rome, Italy
| | | | - Massimo Mischi
- Department of Electrical Engineering, Eindhoven University of Technology, Netherlands
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7
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Kannojiya V, Das AK, Das PK. Simulation of Blood as Fluid: A Review From Rheological Aspects. IEEE Rev Biomed Eng 2021; 14:327-341. [DOI: 10.1109/rbme.2020.3011182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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8
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Impact of Mitral Regurgitation on the Flow in a Model of a Left Ventricle. Cardiovasc Eng Technol 2020; 11:708-718. [DOI: 10.1007/s13239-020-00490-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 09/24/2020] [Indexed: 11/25/2022]
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9
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Morud JC, Skjetne P, Urheim S, Dahl SK. The effect of chordae tendineae on systolic flow. Comput Biol Med 2019; 109:91-100. [PMID: 31054389 DOI: 10.1016/j.compbiomed.2019.04.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 04/10/2019] [Accepted: 04/20/2019] [Indexed: 11/25/2022]
Abstract
When using Computational Fluid Dynamics to simulate ventricular blood flow in the heart, it has been common practice to neglect the effect of the sub-valvular apparatus and the trabeculae on the flow conditions. In this study, we analyze the effect of neglecting the chordae tendineae on the fluid flow and pressure drop. To test the assumption we use a previously developed dynamic 3D model of the left ventricle, aorta and valves that is based on 3D echocardiographic recordings. To this model we add the chordae tendineae as a sub-grid model. The previously developed 3D model for the left ventricle during systole is based on real-time three-dimensional echocardiography (RT3DE) recordings of a 30 years old female volunteer. The segmented ventricular wall does not include details of the aorta and the mitral valve, so these were reconstructed. The subgrid model for the flow across the chordae tendineae is based on the Actuator Line Method, which means that they are represented by drag coefficients. The analysis shows that the effect of the chordae tendineae on the pressure drop and work efficiency of the normal heart during systole is minor, and it seems that for simulating ventricular fluid flow and pressure drop during systole, one can follow the current practice and ignore the chordae. However, there can be local effects such as small vortices behind the chordae. Whether such effects are important for a particular application must be evaluated for the given case.
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10
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Effects of left atrium on intraventricular flow in numerical simulations. Comput Biol Med 2019; 106:46-53. [DOI: 10.1016/j.compbiomed.2019.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 01/15/2019] [Accepted: 01/15/2019] [Indexed: 01/07/2023]
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11
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Khalafvand SS, Xu F, Westenberg J, Gijsen F, Kenjeres S. Intraventricular blood flow with a fully dynamic mitral valve model. Comput Biol Med 2019; 104:197-204. [DOI: 10.1016/j.compbiomed.2018.11.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 11/25/2022]
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12
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Zhong L, Zhang JM, Su B, Tan RS, Allen JC, Kassab GS. Application of Patient-Specific Computational Fluid Dynamics in Coronary and Intra-Cardiac Flow Simulations: Challenges and Opportunities. Front Physiol 2018; 9:742. [PMID: 29997520 PMCID: PMC6028770 DOI: 10.3389/fphys.2018.00742] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 05/28/2018] [Indexed: 12/13/2022] Open
Abstract
The emergence of new cardiac diagnostics and therapeutics of the heart has given rise to the challenging field of virtual design and testing of technologies in a patient-specific environment. Given the recent advances in medical imaging, computational power and mathematical algorithms, patient-specific cardiac models can be produced from cardiac images faster, and more efficiently than ever before. The emergence of patient-specific computational fluid dynamics (CFD) has paved the way for the new field of computer-aided diagnostics. This article provides a review of CFD methods, challenges and opportunities in coronary and intra-cardiac flow simulations. It includes a review of market products and clinical trials. Key components of patient-specific CFD are covered briefly which include image segmentation, geometry reconstruction, mesh generation, fluid-structure interaction, and solver techniques.
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Affiliation(s)
- Liang Zhong
- National Heart Centre Singapore, National Heart Research Institute of Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Jun-Mei Zhang
- National Heart Centre Singapore, National Heart Research Institute of Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Boyang Su
- National Heart Centre Singapore, National Heart Research Institute of Singapore, Singapore, Singapore
| | - Ru San Tan
- National Heart Centre Singapore, National Heart Research Institute of Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | | | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, United States
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13
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Assessment of human left ventricle flow using statistical shape modelling and computational fluid dynamics. J Biomech 2018; 74:116-125. [PMID: 29729852 DOI: 10.1016/j.jbiomech.2018.04.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 04/10/2018] [Accepted: 04/14/2018] [Indexed: 10/17/2022]
Abstract
Blood flow patterns in the human left ventricle (LV) have shown relation to cardiac health. However, most studies in the literature are limited to a few patients and results are hard to generalize. This study aims to provide a new framework to generate more generalized insights into LV blood flow as a function of changes in anatomy and wall motion. In this framework, we studied the four-dimensional blood flow in LV via computational fluid dynamics (CFD) in conjunction with a statistical shape model (SSM), built from segmented LV shapes of 150 subjects. We validated results in an in-vitro dynamic phantom via time-resolved optical particle image velocimetry (PIV) measurements. This combination of CFD and the SSM may be useful for systematically assessing blood flow patterns in the LV as a function of varying anatomy and has the potential to provide valuable data for diagnosis of LV functionality.
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14
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Caballero A, Mao W, Liang L, Oshinski J, Primiano C, McKay R, Kodali S, Sun W. Modeling Left Ventricular Blood Flow Using Smoothed Particle Hydrodynamics. Cardiovasc Eng Technol 2017; 8:465-479. [PMID: 28744784 DOI: 10.1007/s13239-017-0324-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 07/20/2017] [Indexed: 12/11/2022]
Abstract
This study aims to investigate the capability of smoothed particle hydrodynamics (SPH), a fully Lagrangian mesh-free method, to simulate the bulk blood flow dynamics in two realistic left ventricular (LV) models. Three dimensional geometries and motion of the LV, proximal left atrium and aortic root are extracted from cardiac magnetic resonance imaging and multi-slice computed tomography imaging data. SPH simulation results are analyzed and compared with those obtained using a traditional finite volume-based numerical method, and to in vivo phase contrast magnetic resonance imaging and echocardiography data, in terms of the large-scale blood flow phenomena usually clinically measured. A quantitative comparison of the velocity fields and global flow parameters between the in silico models and the in vivo data shows a reasonable agreement, given the inherent uncertainties and limitations in the modeling and imaging techniques. The results indicate the capability of SPH as a promising tool for predicting clinically relevant large-scale LV flow information.
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Affiliation(s)
- Andrés Caballero
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Wenbin Mao
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Liang Liang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - John Oshinski
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.,Department of Radiology & Imaging Science, Emory University, Atlanta, GA, USA
| | | | - Raymond McKay
- Cardiology Department, The Hartford Hospital, Hartford, CT, USA
| | - Susheel Kodali
- Structural Heart & Valve Center, Columbia University Medical Center, New York, NY, USA
| | - Wei Sun
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
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15
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Three-dimensional diastolic blood flow in the left ventricle. J Biomech 2017; 50:71-76. [DOI: 10.1016/j.jbiomech.2016.11.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 11/02/2016] [Indexed: 11/20/2022]
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16
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Doost SN, Ghista D, Su B, Zhong L, Morsi YS. Heart blood flow simulation: a perspective review. Biomed Eng Online 2016; 15:101. [PMID: 27562639 PMCID: PMC5000510 DOI: 10.1186/s12938-016-0224-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 08/15/2016] [Indexed: 02/03/2023] Open
Abstract
Cardiovascular disease (CVD), the leading cause of death today, incorporates a wide range of cardiovascular system malfunctions that affect heart functionality. It is believed that the hemodynamic loads exerted on the cardiovascular system, the left ventricle (LV) in particular, are the leading cause of CVD initiation and propagation. Moreover, it is believed that the diagnosis and prognosis of CVD at an early stage could reduce its high mortality and morbidity rate. Therefore, a set of robust clinical cardiovascular assessment tools has been introduced to compute the cardiovascular hemodynamics in order to provide useful insights to physicians to recognize indicators leading to CVD and also to aid the diagnosis of CVD. Recently, a combination of computational fluid dynamics (CFD) and different medical imaging tools, image-based CFD (IB-CFD), has been widely employed for cardiovascular functional assessment by providing reliable hemodynamic parameters. Even though the capability of CFD to provide reliable flow dynamics in general fluid mechanics problems has been widely demonstrated for many years, up to now, the clinical implications of the IB-CFD patient-specific LVs have not been applicable due to its limitations and complications. In this paper, we review investigations conducted to numerically simulate patient-specific human LV over the past 15 years using IB-CFD methods. Firstly, we divide different studies according to the different LV types (physiological and different pathological conditions) that have been chosen to reconstruct the geometry, and then discuss their contributions, methodologies, limitations, and findings. In this regard, we have studied CFD simulations of intraventricular flows and related cardiology insights, for (i) Physiological patient-specific LV models, (ii) Pathological heart patient-specific models, including myocardial infarction, dilated cardiomyopathy, hypertrophic cardiomyopathy and hypoplastic left heart syndrome. Finally, we discuss the current stage of the IB-CFD LV simulations in order to mimic realistic hemodynamics of patient-specific LVs. We can conclude that heart flow simulation is on the right track for developing into a useful clinical tool for heart function assessment, by (i) incorporating most of heart structures' (such as heart valves) operations, and (ii) providing useful diagnostic indices based hemodynamic parameters, for routine adoption in clinical usage.
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Affiliation(s)
- Siamak N Doost
- Biomechanics and Tissue Engineering Lab, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Australia
| | | | - Boyang Su
- National Heart Research Institute Singapore, National Heart Centre Singapore, 5 Hospital Drive, 169609, Singapore, Singapore
| | - Liang Zhong
- National Heart Research Institute Singapore, National Heart Centre Singapore, 5 Hospital Drive, 169609, Singapore, Singapore. .,Duke-NUS Medical School, Singapore, Singapore.
| | - Yosry S Morsi
- Biomechanics and Tissue Engineering Lab, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Australia
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Wan M, Huang W, Zhang JM, Zhao X, Allen JC, Tan RS, Wan X, Zhong L. Correcting motion in multiplanar cardiac magnetic resonance images. Biomed Eng Online 2016; 15:93. [PMID: 27503101 PMCID: PMC4977636 DOI: 10.1186/s12938-016-0216-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 07/27/2016] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Misalignment in cardiac magnetic resonance (CMR) images can adversely affect three-dimensional left ventricle modelling and downstream quantitative analysis. Currently, there are two types of approaches for dealing with realignment and motion distortion problems, one image based and the other geometry based. Image-based approaches are limited by the inherent non-homogeneity and anisotropy of CMR images. Geometry-based approaches rely on idealized models and over-simplified assumptions. This study was motivated by the need for a robust and effective approach for correcting motion related distortions due to misalignment in CMR images. METHODS A cine cardiac magnetic resonance image sequence was acquired using our routine clinical imaging protocol. The left ventricular endocardium was delineated manually with software assistance on all long and short-axis images. Long and short-axis contours were projected onto a patient-based coordinate system and then realigned using iterative registration. The realigned contour points were used to reconstruct the shape of the left ventricle for quantitative validation. RESULTS The method was tested on five myocardial infarction patients whose images showed substantial misalignment. Realignment time was about 16 seconds per case, using a 2.5 GHz CPU desktop with obvious elimination of the distortion in the reconstructed model. Using the long-axis contour as a reference in evaluating the reconstructed models, it was apparent that the models with realigned contours had better accuracy than the non-realigned ones. CONCLUSION This study presents a novel, geometry-based method for correcting motion distortions in CMR images. The method incorporates (1) manual delineation, (2) registration based on a generalized, iterative closest point algorithm, and (3) reconstruction of the shape of the left ventricle for quantitative validation. The effectiveness of our approach is corroborated both visually and by quantitative assessment. We envision the use of our method in current clinical practice as a means of improving accuracy in the evaluation of cardiac function.
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Affiliation(s)
- Min Wan
- Nanchang University, No. 999, Xuefu Dadao, Nanchang, People’s Republic of China
| | - Wei Huang
- Nanchang University, No. 999, Xuefu Dadao, Nanchang, People’s Republic of China
| | - Jun-Mei Zhang
- National Heart Centre Singapore, 5 Hospital Drive, Singapore, 169609 Singapore
- Duke-NUS Medical School Singapore, 8 College Road, Singapore, 169857 Singapore
| | - Xiaodan Zhao
- National Heart Centre Singapore, 5 Hospital Drive, Singapore, 169609 Singapore
| | - John Carson Allen
- Duke-NUS Medical School Singapore, 8 College Road, Singapore, 169857 Singapore
| | - Ru San Tan
- National Heart Centre Singapore, 5 Hospital Drive, Singapore, 169609 Singapore
- Duke-NUS Medical School Singapore, 8 College Road, Singapore, 169857 Singapore
| | - Xiaofeng Wan
- Nanchang University, No. 999, Xuefu Dadao, Nanchang, People’s Republic of China
| | - Liang Zhong
- National Heart Centre Singapore, 5 Hospital Drive, Singapore, 169609 Singapore
- Duke-NUS Medical School Singapore, 8 College Road, Singapore, 169857 Singapore
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Doost SN, Zhong L, Su B, Morsi YS. The numerical analysis of non-Newtonian blood flow in human patient-specific left ventricle. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2016; 127:232-247. [PMID: 26849955 DOI: 10.1016/j.cmpb.2015.12.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 12/21/2015] [Indexed: 06/05/2023]
Abstract
Recently, various non-invasive tools such as the magnetic resonance image (MRI), ultrasound imaging (USI), computed tomography (CT), and the computational fluid dynamics (CFD) have been widely utilized to enhance our current understanding of the physiological parameters that affect the initiation and the progression of the cardiovascular diseases (CVDs) associated with heart failure (HF). In particular, the hemodynamics of left ventricle (LV) has attracted the attention of the researchers due to its significant role in the heart functionality. In this study, CFD owing its capability of predicting detailed flow field was adopted to model the blood flow in images-based patient-specific LV over cardiac cycle. In most published studies, the blood is modeled as Newtonian that is not entirely accurate as the blood viscosity varies with the shear rate in non-linear manner. In this paper, we studied the effect of Newtonian assumption on the degree of accuracy of intraventricular hemodynamics. In doing so, various non-Newtonian models and Newtonian model are used in the analysis of the intraventricular flow and the viscosity of the blood. Initially, we used the cardiac MRI images to reconstruct the time-resolved geometry of the patient-specific LV. After the unstructured mesh generation, the simulations were conducted in the CFD commercial solver FLUENT to analyze the intraventricular hemodynamic parameters. The findings indicate that the Newtonian assumption cannot adequately simulate the flow dynamic within the LV over the cardiac cycle, which can be attributed to the pulsatile and recirculation nature of the flow and the low blood shear rate.
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Affiliation(s)
- Siamak N Doost
- Biomechanical and Tissue Engineering Lab, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Australia.
| | - Liang Zhong
- Duke-NUS Graduate Medical School, Singapore; National Heart Research Institute of Singapore, National Heart Centre, Singapore.
| | - Boyang Su
- National Heart Research Institute of Singapore, National Heart Centre, Singapore
| | - Yosry S Morsi
- Biomechanical and Tissue Engineering Lab, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Australia
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Su B, Tan RS, Tan JL, Guo KWQ, Zhang JM, Leng S, Zhao X, Allen JC, Zhong L. Cardiac MRI based numerical modeling of left ventricular fluid dynamics with mitral valve incorporated. J Biomech 2016; 49:1199-1205. [PMID: 26993615 DOI: 10.1016/j.jbiomech.2016.03.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 03/01/2016] [Accepted: 03/03/2016] [Indexed: 11/27/2022]
Abstract
Recent numerical studies were focused on the modeling of flow in patient-specific left ventricle (LV); however, the mitral valve (MV) was usually excluded. In this study, both patient-specific LV and MV were modeled to achieve a more realistic intraventricular flow. Cardiac MRI images were acquired from a pulmonary arterial hypertension (PAH) patient and a healthy volunteer, and manual segmentation was conducted to reconstruct three-dimensional (3D) LV and MV geometries at each frame. Based on these 3D geometries, vortex formation time (VFT) was derived, and the values were 4.0 and 6.5 for the normal subject and the PAH patient, respectively. Based on studies in the literature, VTF in the healthy subject fell within the normal range, while that in the PAH patient exceeded the threshold for normality. The vortex structures in the LV clearly showed that the vortex ring was initiated from the tips of the MV instead of the mitral annulus. The excessive VFT during the rapid filling phase in the PAH patient resulted in a trailing flow structure behind the primary vortex ring, which was not observed in the normal subject. It can be deduced from this study that incorporating the MV into a patient-specific model is necessary to produce more reasonable VFT and intraventricular flow.
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Affiliation(s)
- Boyang Su
- National Heart Centre Singapore, 5 Hospital Drive, 169609, Singapore
| | - Ru San Tan
- National Heart Centre Singapore, 5 Hospital Drive, 169609, Singapore; Duke-NUS Graduate Medical School Singapore, Singapore
| | - Ju Le Tan
- National Heart Centre Singapore, 5 Hospital Drive, 169609, Singapore
| | | | - Jun Mei Zhang
- National Heart Centre Singapore, 5 Hospital Drive, 169609, Singapore; Duke-NUS Graduate Medical School Singapore, Singapore
| | - Shuang Leng
- National Heart Centre Singapore, 5 Hospital Drive, 169609, Singapore
| | - Xiaodan Zhao
- National Heart Centre Singapore, 5 Hospital Drive, 169609, Singapore
| | | | - Liang Zhong
- National Heart Centre Singapore, 5 Hospital Drive, 169609, Singapore; Duke-NUS Graduate Medical School Singapore, Singapore.
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Wan M, Huang W, Zhang JM, Zhao X, Tan RS, Wan X, Zhong L. Variational Reconstruction of Left Cardiac Structure from CMR Images. PLoS One 2015; 10:e0145570. [PMID: 26689551 PMCID: PMC4699201 DOI: 10.1371/journal.pone.0145570] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 12/04/2015] [Indexed: 11/20/2022] Open
Abstract
Cardiovascular Disease (CVD), accounting for 17% of overall deaths in the USA, is the leading cause of death over the world. Advances in medical imaging techniques make the quantitative assessment of both the anatomy and function of heart possible. The cardiac modeling is an invariable prerequisite for quantitative analysis. In this study, a novel method is proposed to reconstruct the left cardiac structure from multi-planed cardiac magnetic resonance (CMR) images and contours. Routine CMR examination was performed to acquire both long axis and short axis images. Trained technologists delineated the endocardial contours. Multiple sets of two dimensional contours were projected into the three dimensional patient-based coordinate system and registered to each other. The union of the registered point sets was applied a variational surface reconstruction algorithm based on Delaunay triangulation and graph-cuts. The resulting triangulated surfaces were further post-processed. Quantitative evaluation on our method was performed via computing the overlapping ratio between the reconstructed model and the manually delineated long axis contours, which validates our method. We envisage that this method could be used by radiographers and cardiologists to diagnose and assess cardiac function in patients with diverse heart diseases.
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Affiliation(s)
- Min Wan
- Nanchang University, Nanchang, Jiangxi Province, P.R.China 330031
- * E-mail: (MW); (LZ)
| | - Wei Huang
- Nanchang University, Nanchang, Jiangxi Province, P.R.China 330031
| | - Jun-Mei Zhang
- National Heart Centre Singapore, 5 Hospital Drive, Singapore 169609, Singapore
- Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857, Singapore
| | - Xiaodan Zhao
- National Heart Centre Singapore, 5 Hospital Drive, Singapore 169609, Singapore
| | - Ru San Tan
- National Heart Centre Singapore, 5 Hospital Drive, Singapore 169609, Singapore
- Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857, Singapore
| | - Xiaofeng Wan
- Nanchang University, Nanchang, Jiangxi Province, P.R.China 330031
| | - Liang Zhong
- National Heart Centre Singapore, 5 Hospital Drive, Singapore 169609, Singapore
- Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857, Singapore
- * E-mail: (MW); (LZ)
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Su B, Kabinejadian F, Phang HQ, Kumar GP, Cui F, Kim S, Tan RS, Hon JKF, Allen JC, Leo HL, Zhong L. Numerical Modeling of Intraventricular Flow during Diastole after Implantation of BMHV. PLoS One 2015; 10:e0126315. [PMID: 25961285 PMCID: PMC4427484 DOI: 10.1371/journal.pone.0126315] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 03/31/2015] [Indexed: 12/20/2022] Open
Abstract
This work presents a numerical simulation of intraventricular flow after the implantation of a bileaflet mechanical heart valve at the mitral position. The left ventricle was simplified conceptually as a truncated prolate spheroid and its motion was prescribed based on that of a healthy subject. The rigid leaflet rotation was driven by the transmitral flow and hence the leaflet dynamics were solved using fluid-structure interaction approach. The simulation results showed that the bileaflet mechanical heart valve at the mitral position behaved similarly to that at the aortic position. Sudden area expansion near the aortic root initiated a clockwise anterior vortex, and the continuous injection of flow through the orifice resulted in further growth of the anterior vortex during diastole, which dominated the intraventricular flow. This flow feature is beneficial to preserving the flow momentum and redirecting the blood flow towards the aortic valve. To the best of our knowledge, this is the first attempt to numerically model intraventricular flow with the mechanical heart valve incorporated at the mitral position using a fluid-structure interaction approach. This study facilitates future patient-specific studies.
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Affiliation(s)
- Boyang Su
- National Heart Research Institute of Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Foad Kabinejadian
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Hui Qun Phang
- Department of Surgery, National University of Singapore, Singapore, Singapore
| | | | - Fangsen Cui
- Institute of High Performance Computing, ASTAR, Singapore, Singapore
| | - Sangho Kim
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Ru San Tan
- National Heart Research Institute of Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Jimmy Kim Fatt Hon
- Department of Surgery, National University of Singapore, Singapore, Singapore
| | | | - Hwa Liang Leo
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Liang Zhong
- National Heart Research Institute of Singapore, National Heart Centre Singapore, Singapore, Singapore
- Duke-NUS Graduate Medical School, Singapore, Singapore
- * E-mail:
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