Finite element analyses of uniform current density electrodes for radio-frequency cardiac ablation

Tungjitkusolmun, S.; Woo, Eung Je; Cao, Hong; Tsai, Jang-Zern; Vorperian, Vicken R.; Webster, John G.

doi:10.1109/10.817617

Cited by 80 publications

(59 citation statements)

References 20 publications

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“…However, to our knowledge, the majority of the numerical models of RF heating using an active electrode include only a limited fragment of biological tissue and active electrode [17,19,22,26,[36][37][38][39]. Computer simulations have been carried out in all these cases in order to determine the appropriate model dimensions.…”

Section: H Electrical Conductivity Dispersionmentioning

confidence: 99%

Radio-frequency heating of the cornea: theoretical model and in vitro experiments

Berjano

Sáiz

Ferrero

2002

IEEE Trans. Biomed. Eng.

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We present a theoretical model for the study of cornea heating with radiofrequency currents. This technique is used to reshape the cornea to correct refractive disorders. Our numerical model has allowed the study of the temperature distributions in the cornea and to estimate the dimensions of the lesion. The model incorporates a fragment of cornea, aqueous humor and the active electrode placed on the cornea surface. The finite element method has been used to calculate the temperature distribution in the cornea by solving a coupled electric-thermal problem. We analyzed by means of computer simulations the effect of: a) temperature influence on the tissue electrical conductivity, b) the dispersion of the biological characteristics, c) the anisotropy of the cornea thermal conductivity, d) the presence of the tear film, and e) the insertion depth of the active electrode in the cornea, and the results suggest that these effects have a significant influence on the temperature distributions and thereby on the lesion dimensions. However, the cooling of the aqueous humor in the endothelium or the realistic value of the cornea curvature did not have a significant effect on the temperature distributions.An experimental model based on the lesions created in rabbit eyes has been used in order to compare the theoretical and experimental results. There is a tendency towards the agreement between experimental and theoretical results, although we have observed that the theoretical model overestimates the lesion dimension.

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Section: H Electrical Conductivity Dispersionmentioning

confidence: 99%

Radio-frequency heating of the cornea: theoretical model and in vitro experiments

Berjano

Sáiz

Ferrero

2002

IEEE Trans. Biomed. Eng.

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“…In order to know the change in potential and temperature distributions in the hepatic tissue during ablation, we solved the bioheat equation. As the geometries of the objects involved in RF hepatic ablation (RF probe, blood vessels, hepatic tissue) are complicated, we use FEM method models to solve the bioheat three-dimensional (3-D) FEM modeling studies of RF cardiac ablation have been presented [9]- [11]. However, no previous studies have introduced any 3-D numerical model that includes a realistic probe for hepatic RF ablation.…”

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confidence: 99%

Three-dimensional finite-element analyses for radio-frequency hepatic tumor ablation

Tungjitkusolmun

Staelin

Haemmerich

et al. 2002

IEEE Trans. Biomed. Eng.

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296

184

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Abstract-Radio-frequency (RF) hepatic ablation, offers an alternative method for the treatment of hepatic malignancies. We employed finite-element method (FEM) analysis to determine tissue temperature distribution during RF hepatic ablation. We constructed three-dimensional (3-D) thermal-electrical FEM models consisting of a four-tine RF probe, hepatic tissue, and a large blood vessel (10-mm diameter) located at different locations. We simulated our FEM analyses under temperature-controlled (90 C) 8-min ablation. We also present a preliminary result from a simplified two-dimensional (2-D) FEM model that includes a bifurcated blood vessel. Lesion shapes created by the four-tine RF probe were mushroom-like, and were limited by the blood vessel. When the distance of the blood vessel was 5 mm from the nearest distal electrode 1) in the 3-D model, the maximum tissue temperature (hot spot) appeared next to electrods A. The location of the hot spot was adjacent to another electrode 2) on the opposite side when the blood vessel was 1 mm from electrode A. The temperature distribution in the 2-D model was highly nonuniform due to the presence of the bifurcated blood vessel. Underdosed areas might be present next to the blood vessel from which the tumor can regenerate.

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“…Heat increase due to electrical stimulation of the tissue is categorized into two main sections, namely Joule heat and metabolic reactions [13], [14]. Joule heat forms in the presence of electric field.…”

Section: The Effect Of Temperature Rise In Tissuesmentioning

confidence: 99%

The Effect of the Electrical Stimulation on Temperature Rise in the Retinal Tissue for Visual Prostheses

Celik¹,

Karagöz²

2014

IJCEE

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Abstract-Visual perception which is one of the most valuable perceptions for human beings may be lost over time because of various diseases such as Age Related Macular Degeneration (AMD) and Retinitis Pigmentosa (RP). These degenerative diseases cause severe damage to the certain parts of visual pathway and irreversible blindness. For the past last decades, with the improvements in the areas such as microelectronics, neuroscience and bioengineering, researches conducting on design and implementation of visual prosthetics become a promising therapeutic approach for the visual restoration. Visual perception, called phosphene, is reported to be obtained in studies which are based on electrical stimulation of the intact parts of the visual pathway. There are major factors that have to be considered in the design stage of a visual prosthesis system. One of them is the temperature change of the targeted retinal tissue and its surrounding due to electrical stimulation. In this study, a model is created to investigate thermal influence of an implant placed internal surface of the retinal tissue and solution is made using finite element analysis. It is shown that the temperature rise has highest value near the stimulation electrode and its surroundings in the case of using the model with thermal insulation. When the heat transfer mechanism is added to the simulation model, it is seen that the temperature rise is less and looks more realistic. With additive effect of heat transfer to the surrounding tissue and distance from stimulation electrode, temperature decreases away from the stimulation electrode.Index Terms-Electrical stimulation, finite element analysis, temperature change, visual prosthesis.

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Finite element analyses of uniform current density electrodes for radio-frequency cardiac ablation

Cited by 80 publications

References 20 publications

Radio-frequency heating of the cornea: theoretical model and in vitro experiments

Radio-frequency heating of the cornea: theoretical model and in vitro experiments

Three-dimensional finite-element analyses for radio-frequency hepatic tumor ablation

The Effect of the Electrical Stimulation on Temperature Rise in the Retinal Tissue for Visual Prostheses

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