Computational Modeling of Cardiac Ablation Incorporating Electrothermomechanical Interactions

2020 ◽  
Vol 3 (4) ◽  
Author(s):  
Sundeep Singh ◽  
Roderick Melnik
Keyword(s):  
Blood Flow ◽  
Computational Modeling ◽  
Radio Frequency ◽  
Treatment Outcomes ◽  
Cardiac Tissue ◽  
Numerical Study ◽  
Cardiac Ablation ◽  
Cardiac Chamber ◽  
Ablation Volume ◽  
Fully Coupled

Abstract The application of radio frequency ablation (RFA) has been widely explored in treating various types of cardiac arrhythmias. Computational modeling provides a safe and viable alternative to ex vivo and in vivo experimental studies for quantifying the effects of different variables efficiently and reliably, apart from providing a priori estimates of the ablation volume attained during cardiac ablation procedures. In this contribution, we report a fully coupled electrothermomechanical model for a more accurate prediction of the treatment outcomes during the radio frequency cardiac ablation. A numerical model comprising of cardiac tissue and the cardiac chamber has been developed in which an electrode has been inserted perpendicular to the cardiac tissue to simulate actual clinical procedures. Temperature-dependent heat capacity, electrical and thermal conductivities, and blood perfusion rate have been considered to model more realistic scenarios. The effects of blood flow and contact force of the electrode tip on the treatment outcomes of a fully coupled model of RFA have been systematically investigated. The numerical study demonstrates that the predicted ablation volume of RFA is significantly dependent on the blood flow rate in the cardiac chamber and also on the tissue deformation induced due to electrode insertion depth of 1.5 mm or higher.

Computational Model of Radiofrequency Ablation of Cardiac Tissues Incorporating Thermo-Electro-Mechanical Interactions

2020 ◽  
Author(s):  
Sundeep Singh ◽  
Roderick Melnik
Keyword(s):  
Radiofrequency Ablation ◽  
Cardiac Tissue ◽  
A Priori Estimates ◽  
Ex Vivo ◽  
Numerical Study ◽  
Experimental Studies ◽  
Computational Modelling ◽  
Cardiac Ablation ◽  
Fully Coupled

Abstract The application of radiofrequency ablation (RFA) has been widely explored in treating various types of cardiac arrhythmias. Computational modelling provides a safe and viable alternative to ex vivo and in vivo experimental studies for quantifying the effects of different variables efficiently and reliably, apart from providing a priori estimates of the ablation volume attained during cardiac ablation procedures. In this contribution, we report a fully coupled thermo-electro-mechanical model for a more accurate prediction of the treatment outcomes during the radiofrequency cardiac ablation. A numerical model comprising of cardiac tissue and the cardiac chamber has been developed in which an electrode has been inserted perpendicular to the cardiac tissue to simulate actual clinical procedures. Temperature-dependent heat capacity, electrical and thermal conductivities, and blood perfusion rate have been considered to model more realistic scenarios. The effects of blood flow and contact force of the electrode tip on the efficacy of a fully coupled model of RFA have been systematically investigated. The numerical study predicts that the efficacy of RFA is significantly dependent on the thermo-electro-mechanical parameters of the cardiac tissue.

scholarly journals Fluid–Structure Interaction and Non-Fourier Effects in Coupled Electro-Thermo-Mechanical Models for Cardiac Ablation

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 294
Author(s):  
Sundeep Singh ◽  
Roderick Melnik
Keyword(s):  
Relaxation Time ◽  
Temperature Distribution ◽  
Treatment Outcomes ◽  
Cardiac Tissue ◽  
Fluid Structure Interaction ◽  
Thermal Relaxation ◽  
Cardiac Ablation ◽  
Time Effects ◽  
Structure Interaction ◽  
Electrode Insertion

In this study, a fully coupled electro-thermo-mechanical model of radiofrequency (RF)-assisted cardiac ablation has been developed, incorporating fluid–structure interaction, thermal relaxation time effects and porous media approach. A non-Fourier based bio-heat transfer model has been used for predicting the temperature distribution and ablation zone during the cardiac ablation. The blood has been modeled as a Newtonian fluid and the velocity fields are obtained utilizing the Navier–Stokes equations. The thermal stresses induced due to the heating of the cardiac tissue have also been accounted. Parametric studies have been conducted to investigate the effect of cardiac tissue porosity, thermal relaxation time effects, electrode insertion depths and orientations on the treatment outcomes of the cardiac ablation. The results are presented in terms of predicted temperature distributions and ablation volumes for different cases of interest utilizing a finite element based COMSOL Multiphysics software. It has been found that electrode insertion depth and orientation has a significant effect on the treatment outcomes of cardiac ablation. Further, porosity of cardiac tissue also plays an important role in the prediction of temperature distribution and ablation volume during RF-assisted cardiac ablation. Moreover, thermal relaxation times only affect the treatment outcomes for shorter treatment times of less than 30 s.

scholarly journals Numerical Study of Blood Flow Through Artificial Heart Valves

2021 ◽  
Vol 1094 (1) ◽  
pp. 012120
Author(s):  
Hussein Togun ◽  
Ali Abdul Hussain ◽  
Saja Ahmed ◽  
Iman Abdul hussain ◽  
Huda Shaker
Keyword(s):  
Blood Flow ◽  
Artificial Heart ◽  
Heart Valves ◽  
Numerical Study ◽  
Artificial Heart Valves ◽  
Flow Through

scholarly journals Recapitulating Cardiac Structure and Function In Vitro from Simple to Complex Engineering

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 386
Author(s):  
Ana Santos ◽  
Yongjun Jang ◽  
Inwoo Son ◽  
Jongseong Kim ◽  
Yongdoo Park
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Computational Modeling ◽  
Cardiac Tissue ◽  
Cardiac Development ◽  
Heart Tissue ◽  
Cardiac Tissue Engineering ◽  
Cardiac Cells

Cardiac tissue engineering aims to generate in vivo-like functional tissue for the study of cardiac development, homeostasis, and regeneration. Since the heart is composed of various types of cells and extracellular matrix with a specific microenvironment, the fabrication of cardiac tissue in vitro requires integrating technologies of cardiac cells, biomaterials, fabrication, and computational modeling to model the complexity of heart tissue. Here, we review the recent progress of engineering techniques from simple to complex for fabricating matured cardiac tissue in vitro. Advancements in cardiomyocytes, extracellular matrix, geometry, and computational modeling will be discussed based on a technology perspective and their use for preparation of functional cardiac tissue. Since the heart is a very complex system at multiscale levels, an understanding of each technique and their interactions would be highly beneficial to the development of a fully functional heart in cardiac tissue engineering.

A NUMERICAL STUDY ON THE HEMODYNAMIC AND SHEAR STRESS OF DOUBLE ANEURYSM THROUGH S-SHAPED VESSEL

2015 ◽  
Vol 27 (04) ◽  
pp. 1550033 ◽  
Author(s):  
Mahdi Halabian ◽  
Alireza Karimi ◽  
Borhan Beigzadeh ◽  
Mahdi Navidbakhsh
Keyword(s):  
Blood Flow ◽  
Mechanical Behavior ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
The Body ◽  
Sweep Angle ◽  
Abdominal Aortic ◽  
Hemodynamic Characteristics ◽  
Refined Meshes

Abdominal aortic aneurysm (AAA) is a degenerative disease defined as the abnormal ballooning of the abdominal aorta (AA) wall which is usually caused by atherosclerosis. The aneurysm grows larger and eventually ruptures if it is not diagnosed and treated. Aneurysms occur mostly in the aorta, the main artery of the chest and abdomen. The aorta carries blood flow from the heart to all parts of the body, including the vital organs, the legs, and feet. The objective of the present study is to investigate the combined effects of aneurysm and curvature on flow characteristics in S-shaped bends with sweep angle of 90° at Reynolds number of 900. The fluid mechanics of blood flow in a curved artery with abnormal aortic is studied through a mathematical analysis and employing Cosmos flow simulation. Blood is modeled as an incompressible non-Newtonian fluid and the flow is assumed to be steady and laminar. Hemodynamic characteristics are analyzed. Grid independence is tested on three successively refined meshes. It is observed that the abrupt expansion induced by AAA results in an immensely disturbed regime. The results may have implications not only for understanding the mechanical behavior of the blood flow inside an aneurysm artery but also for investigating the mechanical behavior of the blood flow in different arterial diseases, such as atherosclerosis.

Cold heavy oil production and production by radio-frequency electromagnetic radiation: Comparative numerical study

2016 ◽  
Author(s):  
Alfred Davletbaev ◽  
Victor Kireev ◽  
Liana Kovaleva ◽  
Aleksey Zainullin ◽  
Rais Minnigalimov
Keyword(s):  
Radio Frequency ◽  
Electromagnetic Radiation ◽  
Heavy Oil ◽  
Numerical Study ◽  
Oil Production

Relationship of pyruvate and lactate during anaerobic metabolism. V: Coronary adequacy

1961 ◽  
Vol 200 (6) ◽  
pp. 1169-1176 ◽  
Author(s):  
William E. Huckabee
Keyword(s):  
Blood Flow ◽  
Coronary Flow ◽  
Cardiac Tissue ◽  
Anaerobic Metabolism ◽  
Constant Ratio ◽  
Blood Concentrations ◽  
Arterial Blood ◽  
Anesthetized Dogs ◽  
Relationship Of ◽  
The Relationship

Veno-arterial differences of pyruvate and lactate across the myocardium in chloralose-anesthetized dogs were very variable; in any one animal they changed continually with time despite constant blood flow and arterial blood concentrations. There was a systematic tendency of v-a lactate to vary with v-a pyruvate, as expressed in the calculated "Δ excess lactate," which remained nearly constant (or, if blood flow changed, bore a constant ratio to (a-v)O2). No change in Δ excess lactate from control values occurred in nonhypoxic experiments despite marked changes in v-a differences, arterial blood composition, and coronary flow. Cardiac Δ excess lactate became positive in most animals breathing 10% O2 in N2; output of excess lactate was also observed in all those in which moderate muscular exercise was induced. This anaerobic metabolism, or change in the relationship between pyruvate and lactate exchanges, was interpreted as an indication that O2 delivery response was not adequate to meet cardiac tissue requirements during such mild stresses when judged by the standards of adequacy of the basal state.

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