Towards patient-specific cardiovascular modeling system using the immersed boundary technique

Computational fluid dynamics (CFD) study of the behavior of red blood cells (RBCs) in flow provides us informative insight into the mechanics of blood flow in microvessels. However, the size of computational domain is limited due to computational expense. Recently, we proposed a graphics processing unit (GPU) computing method for patient-specific pulmonary airflow simulations (Miki et al., in press). In this study, we extend this method to micro-scale blood flow simulations, where a lattice Boltzmann method (LBM) of fluid mechanics is coupled with a finite element method (FEM) of membrane mechanics by an immersed boundary method (IBM). We also present validation and performance of our method for micro-scale blood flow simulations.

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3D Reconstruction of the Left Ventricle From Four Echocardiographic Projections

Volume 1A: 34th Computers and Information in Engineering Conference ◽

10.1115/detc2014-34463 ◽

2014 ◽

Cited By ~ 2

Author(s):

Navaneetha Krishnan Rajan ◽

Zeying Song ◽

Kenneth R. Hoffmann ◽

Marek Belohlavek ◽

Eileen M. McMahon ◽

...

Keyword(s):

Left Ventricle ◽

Three Dimensional ◽

Image Data ◽

Left Ventricular ◽

The Body ◽

Patient Specific ◽

Immersed Boundary ◽

Cross Sectional ◽

Standard Format ◽

Automated Method

The left ventricle (LV) of a human heart receives oxygenated blood from the lungs and pumps it throughout the body via the aortic valve. Characterizing the LV geometry, its motion, and the ventricular flow is critical in assessing the heart’s health. An automated method has been developed in this work to generate a three-dimensional (3D) model of the LV from multiple-axis echocardiography (echo). Image data from three long-axis sections and a basal section is processed to compute spatial nodes on the LV surface. The generated surfaces are output in a standard format such that it can be imported into the curvilinear-immersed boundary (CURVIB) framework for numerical simulation of the flow inside the LV. The 3D LV model can be used for better understanding of the ventricular motion and the simulation framework provides a powerful tool for studying left ventricular flows on a patient specific basis. Future work would incorporate data from additional cross-sectional images.

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A Re-Engineered Software Interface and Workflow for the Open-Source SimVascular Cardiovascular Modeling Package

Journal of Biomechanical Engineering ◽

10.1115/1.4038751 ◽

2018 ◽

Vol 140 (2) ◽

Cited By ~ 15

Author(s):

Hongzhi Lan ◽

Adam Updegrove ◽

Nathan M. Wilson ◽

Gabriel D. Maher ◽

Shawn C. Shadden ◽

...

Keyword(s):

Open Source ◽

Computer Aided Design ◽

Three Dimensional ◽

User Interaction ◽

Solid Modeling ◽

Patient Specific ◽

Cardiovascular Modeling ◽

Software Interface ◽

Open Source Software Package ◽

3D Solid

Patient-specific simulation plays an important role in cardiovascular disease research, diagnosis, surgical planning and medical device design, as well as education in cardiovascular biomechanics. simvascular is an open-source software package encompassing an entire cardiovascular modeling and simulation pipeline from image segmentation, three-dimensional (3D) solid modeling, and mesh generation, to patient-specific simulation and analysis. SimVascular is widely used for cardiovascular basic science and clinical research as well as education, following increased adoption by users and development of a GATEWAY web portal to facilitate educational access. Initial efforts of the project focused on replacing commercial packages with open-source alternatives and adding increased functionality for multiscale modeling, fluid–structure interaction (FSI), and solid modeling operations. In this paper, we introduce a major SimVascular (SV) release that includes a new graphical user interface (GUI) designed to improve user experience. Additional improvements include enhanced data/project management, interactive tools to facilitate user interaction, new boundary condition (BC) functionality, plug-in mechanism to increase modularity, a new 3D segmentation tool, and new computer-aided design (CAD)-based solid modeling capabilities. Here, we focus on major changes to the software platform and outline features added in this new release. We also briefly describe our recent experiences using SimVascular in the classroom for bioengineering education.

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Demonstration of Patient-Specific Simulations to Assess Left Atrial Appendage Thrombogenesis Risk

Frontiers in Physiology ◽

10.3389/fphys.2021.596596 ◽

2021 ◽

Vol 12 ◽

Author(s):

Manuel García-Villalba ◽

Lorenzo Rossini ◽

Alejandro Gonzalo ◽

Davis Vigneault ◽

Pablo Martinez-Legazpi ◽

...

Keyword(s):

Residence Time ◽

Left Atrial ◽

Left Atrial Appendage ◽

Blood Stasis ◽

Bleeding Risk ◽

Atrial Appendage ◽

Patient Specific ◽

Immersed Boundary ◽

Moving Wall ◽

And Function

Atrial fibrillation (AF) alters left atrial (LA) hemodynamics, which can lead to thrombosis in the left atrial appendage (LAA), systemic embolism and stroke. A personalized risk-stratification of AF patients for stroke would permit improved balancing of preventive anticoagulation therapies against bleeding risk. We investigated how LA anatomy and function impact LA and LAA hemodynamics, and explored whether patient-specific analysis by computational fluid dynamics (CFD) can predict the risk of LAA thrombosis. We analyzed 4D-CT acquisitions of LA wall motion with an in-house immersed-boundary CFD solver. We considered six patients with diverse atrial function, three with either a LAA thrombus (removed digitally before running the simulations) or a history of transient ischemic attacks (LAAT/TIA-pos), and three without a LAA thrombus or TIA (LAAT/TIA-neg). We found that blood inside the left atrial appendage of LAAT/TIA-pos patients had marked alterations in residence time and kinetic energy when compared with LAAT/TIA-neg patients. In addition, we showed how the LA conduit, reservoir and booster functions distinctly affect LA and LAA hemodynamics. Finally, fixed-wall and moving-wall simulations produced different LA hemodynamics and residence time predictions for each patient. Consequently, fixed-wall simulations risk-stratified our small cohort for LAA thrombosis worse than moving-wall simulations, particularly patients with intermediate LAA residence time. Overall, these results suggest that both wall kinetics and LAA morphology contribute to LAA blood stasis and thrombosis.

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Hybrid 4D cardiovascular modeling based on patient-specific clinical images for real-time PCI surgery simulation

Graphical Models ◽

10.1016/j.gmod.2018.11.002 ◽

2019 ◽

Vol 101 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Shuai Li ◽

Zhijun Xie ◽

Qing Xia ◽

Aimin Hao ◽

Hong Qin

Keyword(s):

Real Time ◽

Patient Specific ◽

Surgery Simulation ◽

Clinical Images ◽

Cardiovascular Modeling

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Patient-specific cardiovascular modeling in pulmonary hypertension : assessment of hemodynamic and mechanical ventricular interaction

10.26481/dis.20100702jl ◽

2010 ◽

Author(s):

J.E. Lumens

Keyword(s):

Pulmonary Hypertension ◽

Patient Specific ◽

Cardiovascular Modeling ◽

Ventricular Interaction

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Demonstration of Patient-Specific Simulations To Assess Left Atrial Appendage Thrombogenesis Risk

10.1101/2020.05.07.083220 ◽

2020 ◽

Author(s):

Manuel García-Villalba ◽

Lorenzo Rossini ◽

Alejandro Gonzalo ◽

Davis Vigneault ◽

Pablo Martinez-Legazpi ◽

...

Keyword(s):

Left Atrial ◽

Left Atrial Appendage ◽

Bleeding Risk ◽

Atrial Appendage ◽

Patient Specific ◽

Immersed Boundary ◽

Moving Wall ◽

History Of ◽

Small Cohort ◽

And Function

AbstractAtrial fibrillation (AF) alters left atrial (LA) hemodynamics, which can lead to thrombosis in the left atrial appendage (LAA), systemic embolism and stroke. A personalized risk-stratification of AF patients for stroke would permit improved balancing of preventive anticoagulation therapies against bleeding risk. We investigated how LA anatomy and function impact LA and LAA hemodynamics, and explored whether patient-specific analysis by computational fluid dynamics (CFD) can predict the risk of LAA thrombosis. We analyzed 4D-CT acquisitions of LA wall motion with an in-house immersed-boundary CFD solver. We considered six patients with diverse atrial function, three without a LAA thrombus (LAAT/TIA-neg), and three with either a LAA thrombus (removed digitally before running the simulations) or a history of transient ischemic attacks (LAAT/TIA-pos). We found that blood inside the left atrial appendage of LAAT/TIA-pos patients had marked alterations in residence time and kinetic energy when compared with LAAT/TIA-neg patients. In addition, we showed how the LA conduit, reservoir and booster functions distinctly affect LA and LAA hemodynamics. While the flow dynamics of fixed-wall and moving-wall simulations differ significantly, fixed-wall simulations risk-stratified our small cohort for LAA thrombosis only slightly worse than moving-wall simulations.

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Development of an Anatomically Realistic Left Ventricle Physical Model and Multi-Modality Experimental Platform for Validation of Patient-Specific Computational Simulations

ASME 2012 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2012-80613 ◽

2012 ◽

Author(s):

Brandon Chaffins ◽

Trung Le ◽

Arvind Santhanakrishnan ◽

Lucia Mirabella ◽

Fotis Sotiropoulos ◽

...

Keyword(s):

Left Ventricle ◽

Physical Model ◽

Heart Diseases ◽

Normal Volunteer ◽

Patient Specific ◽

Immersed Boundary ◽

Reconstruction Method ◽

Left Heart ◽

Recent Trends ◽

Numerical Solver

Recent trends in bioengineering, also supported by the FDA [1], highlight the importance of experimental validation of numerical solvers used in medicine in order to use numerical solvers for surgical planning. Efforts to improve the diagnosis of left heart diseases have pointed to the importance of hemodynamic patterns in the left ventricle [2] and the use of CFD simulations could aid in repair and treatment of left heart disease. In this study, we aim to experimentally validate the Curvilinear Immersed Boundary solver (CURVIB) [3] to use patient specific data for simulations. As a first step, an idealized left heart model with a single deforming wall was used for comparison of the diastolic intra-ventricular flow field between experimental and CFD results. The inputs for the numerical solver include the dynamics of LV wall motion as well as the mitral and aortic flows. We have achieved good agreement between the experimental and CFD and our goal is to translate the solver to use clinical data. We present a reconstruction method for the LV deformation from normal volunteer MRI images and an anatomically realistic LV physical model that has been designed for validation.

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