scholarly journals Relation between denaturation time measured by optical coherence reflectometry and thermal lesion depth during radiofrequency cardiac ablation: Feasibility numerical study

2017 ◽  
Vol 50 (3) ◽  
pp. 222-229 ◽  
Author(s):  
Ana González-Suárez ◽  
David Herranz ◽  
Enrique Berjano ◽  
Jose L. Rubio-Guivernau ◽  
Eduardo Margallo-Balbás
Keyword(s):  
Numerical Study ◽  
Optical Coherence ◽  
Cardiac Ablation ◽  
Thermal Lesion ◽  
Lesion Depth

scholarly journals Thermal and electric Characteristics of High-power Short-duration Radiofrequency Ablation and Standard Radiofrequency Ablation: A Computer Simulation Study

2021 ◽  
Author(s):  
Kaihao Gu ◽  
Shengjie Yan ◽  
Xiaomei Wu
Keyword(s):  
Radiofrequency Ablation ◽  
Short Duration ◽  
High Power ◽  
Lesion Size ◽  
Lesion Volume ◽  
Rf Ablation ◽  
Thermal Lesion ◽  
Lesion Depth ◽  
Lesion Diameter ◽  
Rate Of Increase

Abstract Background: High power-short duration ablation is an emerging conception for cardiac RF treatment. But the biophysical ablation properties of this technique have not been fully explored. This study compared the electric field characteristics and thermal lesion dimension in High power-short duration (HP-SD) radio frequency (RF) ablation and standard RF ablation by using the finite element method. Results: The results demonstrated that the lesion size and temperature in HP–SD RF ablation increased faster than standard RF ablation. The thermal lesion volume in both ablation modes demonstrated a linear increase and the rate of increase of HP–SD RF ablation grew faster than that of standard RF ablation. For HP–SD application at 50 W for 5 s, the lesion depth was shallower (1.74 to 2.1 mm vs 2.40 to 3.15 mm) and the surface lesion diameter was broader (2.76 to 3.32 mm vs 2.42 to 2.66 mm) than that for standard RF ablation at 25 W for 30 s. Conclusion: Compared with standard RF ablation, HP–SD RF ablation creates a broader lesion width and surface lesion diameter but shallower lesion depth, with a faster increase in temperature. HP–SD ablation is more able to achieve uniform and contiguous lesion shape, which is a suitable for point-to-point RF ablation procedures.Higher temperature was formed in deeper space of cardiac tissue in HP–SD ablation. The duration of HP–SD ablation should be strictly controlled for preventing the steam occur in tissue.

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.

Numerical Study of Bubble Cloud and Thermal Lesion Evolution During Acoustic Droplet Vaporization Enhanced Hifu Treatment

2021 ◽  
Author(s):  
Ying Xin ◽  
Aili Zhang ◽  
Lisa X. Xu ◽  
J. Brian Fowlkes
Keyword(s):  
Focused Ultrasound ◽  
Continuous Wave ◽  
Numerical Study ◽  
Wave Exposure ◽  
High Intensity Focused Ultrasound ◽  
Hifu Treatment ◽  
Thermal Lesion ◽  
Acoustic Droplet Vaporization ◽  
Droplet Vaporization ◽  
Bubble Cloud

Abstract Acoustic droplet vaporization (ADV) has proven to enhance high intensity focused ultrasound (HIFU) thermal ablation of tumor. It has also been demonstrated that triggering droplets before HIFU exposure could be a potential way to control both the size and the shape of the thermal lesion. In this paper, a numerical model is proposed to predict the thermal lesion created in ADV enhanced HIFU treatment. Bubble oscillation was coupled into a viscoelastic medium in the model to more closely represent real applications in tissues. Several physical processes caused by continuous wave ultrasound and elevated temperature during the HIFU exposure were considered, including rectified diffusion, gas solubility variation with temperature in the medium, boiling, etc. Four droplet concentrations spanning two orders of magnitude were calculated. The bubble cloud formed from triggering of the droplets by the pulse wave ultrasound, along with the evolution of the shape and location of the bubble cloud and thermal lesion during the following continuous wave exposure were obtained. The increase of bubble void fraction caused by continuous wave exposure were found to be consistent with the experimental observation. With the increase of droplet concentration, the predicted bubble cloud shapes vary from tadpole to triangular and double triangular, while the thermal lesions move toward the transducer. The results show that the assumptions used in this model increased the accuracy of the results. This model may be used for parametrical study of ADV enhanced HIFU treatment and be further used for treatment planning and optimization in the future.

Real-time Imaging of Radiofrequency Cardiac Ablation Using Optical Coherence Tomography

2008 ◽  
Author(s):  
Christine P. Fleming MS ◽  
Hui Wang MS ◽  
Guy Amit MD ◽  
Kara J. Quan MD ◽  
Andrew M. Rollins PhD
Keyword(s):  
Optical Coherence Tomography ◽  
Real Time ◽  
Optical Coherence ◽  
Cardiac Ablation ◽  
Real Time Imaging
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