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Numerical analysis of heat transfer and tissue deformation in liver cancer during microwave ablation: A comparison of bioheat and porous media models
(2025-08-01)
Preechaphonkul, Wutipong
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Mongkol, Vannakorn
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Sakonkanapong, Arnon
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Rattanadecho, Phadungsak
This study presents a numerical comparison of microwave ablation using the Pennes bioheat and porous media models in a deformed liver cancer geometry. A single slot coaxial antenna operating at 2.45 GHz with a power of 10 W for 10 min was simulated using the finite element method, incorporating electromagnetic wave propagation, heat transfer, and tissue deformation. Validation against published experimental data and a mesh independence test confirmed the accuracy of the model. Results indicate up to a 6.7 % higher specific absorption rate in the porous media approach, contributing to a temperature difference of approximately 10–13 % at 10 min compared to the Pennes model. Peak von Mises stress increased by more than 2 Pa in tumor regions, and necrosis progression differed between the models. While both models predicted complete tumor cell death, the Pennes bioheat approach consistently reached thresholds sooner in both tumor and adjacent healthy tissue. These findings highlight the role of tissue porosity and convection in heat transport and deformation, demonstrating the porous media model's improved predictive capability for longer ablation durations and its potential for optimizing treatment protocols.
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Finite Element Analysis on Porous Media: Geometric Monopole Antenna Shapes Affect Liver Tumor Microwave Ablation
(2021-05-14)
Chaichanyut, Wanrunya
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Chaichanyut, Montree
Microwave Ablation is a regularly used medical procedure for removal of the liver tumors, which uses the electromagnetic transform into heat for destruction or kills the hepatic tumor tissue. This paper presents a 3D finite-element method was designing the antenna of 2.45GHz, simulate to investigate analyses of the heating profile during and after hepatic tumor microwave ablation on porous media. The configurations of this study were two Ellipse tip monopole-antennas, which considered were: Symmetric Ellipse tip monopole (S-EM) and Non- symmetric Ellipse tip monopole antennas (NS-EM). The aims of this study to findings revealed that the Specific Absorption Rates (SARs) along the Ellipse monopole-antenna insertion depths, the heating profile and lesion volume (Ablation zone) within the hepatic tumor on porous models with 5 cm-in-diameter tumors. All scenarios were simulated under the temperature-controlled mode (90°C). Simulation results, illustrate that the local peaks of the SARs curves, both antennas occurred at the tip of Ellipse monopole-antenna. The profile of the SARs curves that the S-EM and NS-EM antenna models exhibited similar trends with slightly different amplitudes. The heating profile of both antennas occurred at the lateral around of the antenna, its destroy unwanted tissue. The duration of the NS-EM model was longer than the S-EM model for ablating unwanted tissue. Respectively, the duration ablating of S - EM models and NS-EM model to complete destruction of hepatic tumor were 680s and 700s.
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Optimal antenna slot design for hepatocellular carcinoma microwave ablation using multi-objective fuzzy decision making
(2020-10-01)
Nantivatana, Petch
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Phasukkit, Pattarapong
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Tungjitkusolmun, Supan
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Chayakulkheeree, Keerati
This paper presents the optimal antenna slot position and sizing (OASPS), for microwave (MW) hepatocellular carcinoma (HCC) treatment, using multi-objective fuzzy decision making (MOFDM). In the optimal design problem formulation, the multi-objective for, (1) achievement for a near-spherical zone for ablation defined by axial ratio (AR), (2) the minimum reflection coefficient (S11), and (3) maximum volume of destroying (VD), are desired. The finite element method (FEM) is used for MW distribution simulation for coordination analysis with the proposed MOFDM based OASPS. The investigation on the design results shown that the temperature distribution of the proposed MOFDM for OASPS is in the more controllable shape comparing to the existing design, due to the sharp beam of temperature distribution to the target at the front side of slot with the less temperature distribution at the rare side of slot. The results also show that the proposed MOFDM for OASPS for OASPS design is easier to manage with the less effect to the rare side of the slot. Moreover, the proposed MOFDM for OASPS resulted in the temperature distribution shape closer to round shape than the existing design. The MOFDM for OASPS is tested on designing of the antenna build up from the coaxial cable. The coaxial cable used is Semi-rigid 141 (RG402 M17/130-RG402 Copper Jacket) including Inner conductor, Dielectric, and Outer conductor. In the simulation, the slot distance from conductor end (Lts), representing the slot position, is varied as 2.3mm, 3.3mm, 4.3mm, 5.3mm, 6.3mm, 7.3mm, and 8.3mm. Meanwhile, the slot size (Wd), is varied as 1mm, 2mm, 3mm, 4mm, 5mm, and 6mm. The input power (Pi) used is 50 W with the duration of 300 seconds. The comparison of obtained by different L<inf>ts</inf> and W<inf>d</inf>, is investigated. The simulation results show that the proposed MOFDM based OASPS can efficiently and effectively provide the near-spherical zone of ablation result with simultaneously trade-off between S11 minimization and VD maximization.
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Investigation of Thermal Distribution of Balloon Antenna MWA for Urethra Stricture Treatment
(2019-01-10)
Jandang, Sinchai
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Tungjitkusolmun, Supan
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Phasukkit, Pattarapong
In this paper presented a studying temperature distribution of microwave balloon antenna. Design and analysis by using Comsol Multiphysics program. in vitro experiment with porcine urethral. Validation accuracy out of temperature by use infrared thermometer camera. Also, localized ablation zone by using the colonoscope for confirming the result after an experiment. The results of prevention burn or bleeding and sensitive structure after treatment and all results. Confirm technique for expending urethra stricture by using microwave balloon. In this technique, a research can to treat urethral stricture and other organ in the future.
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The modeling analysis on porous media hepatic cancer for microwave ablation of an interstitial helix-antenna
(2018-06-23)
Chaichanyut, M.
Microwave ablation is processed, which uses the electro-magnetic transform into heat to destruction or kill cancer cells. This study presents analyses of 2.45GHz Helix-antenna configuration and design for porous hepatic cancer microwave ablation by using 3D-finite-element model. The configurations of Helix-antenna were considered: Tipped tip helix antenna (THA) and Extension tip helix antenna (EHA). 3D finite-element models were utilized to investigate the tissue temperature distribution during and after microwave ablation. The study aims to understand the influences of antenna type on the specific absorption rates (SAR) along the helix-antenna insertion depths and the ablation zone (heating profile and lesion volume) inside the hepatic cancer porous models with 5 cm-in-diameter tumor. All scenarios were the initial power was set at 50 W and simulated under temperature-controlled mode (90°C). Based on the preliminary results, the result illustrates that the THA occur the SAR and heating profile at the lateral around of the antenna, while the SAR and heating trend of EHA occur skew toward of the tip antenna. Both antennas destroy unwanted tissue, but the THA use longer duration than EHA for ablating unwanted tissue. The duration of ablation was 700s, respectively, the coagulation volume of THA and EHA were 95.45 and 104.27 cm<sup>3</sup>
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FEM modeling for performance evaluation of microwave ablation applicator when using T prong monopole antennas
(2015-01-01)
Chaichanyut, M.
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Tungjitkusolmun, S.
This paper present three-dimensional finite element method (3D FEMs) simulate of temperature distributions in liver cancer tissue. This study focuses on the evaluation of the performance of a T Prong Monopole Antennas. The configurations of monopole antennas were considered: Two-prong Monopole (2PM), Three-Prong Monopole (3PM) and Equilateral Four-Prong Monopole Antenna (4PM). The 3D FEMs solutions were based on Maxwell and bio-heat equations for studying 2.45GHz T Prong monopole antenna design. We apply the microwave power was 20 W; the duration time for ablation in all case was 300s. From our simulation results, all antennas type have occurred the hotspot at the tip of prong of the antenna. Two-prong Monopole antenna can be induced the highest temperature in cancer tissue. Thermal distributions were obtained and compared. The results indicate that the Two-prong Monopole antenna generated maximum temperature within liver cancer tissue and can be maximum ablation cancer tissue (5.94 cm3). The temperature distribution is determined by the direction of bifurcation of the antenna.
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In vitro practical evaluations on heating characteristics of thin microwave antenna in maximum temperature control mode
(2015-01-01)
Chaichanyut, M.
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Tungjitkusolmun, S.
Microwave thermal therapy is one of the modalities for cancer treatment. There are several schemes of microwave heating. The authors have been studying thin Coaxial Quarter Conductor Antennas (CQCA) for intracavitary microwave heating aiming at the treatment of hepatic cancer. Experimental protocol was composed by a radiation microwave power system and a thermometry system. We apply the microwave power during experiments was 10W, 20W, 30W, 40W, 50W, 60W, 70W and 80W which we set the maximum temperature control at 90°C for all case Experiment, Thermal sensors were placed next to the antenna at 1mm, a large number of experiments on porcine liver are carried out, the temperature distribution within the porcine liver are measured, for cases of different injected microwave power. Experiment for finding a possibility of the treatment. In this study, in order to consider practical situations of the treatment, heating characteristics of the antenna inserted into sample tissue. Moreover, the relation between coagulation size of the tissue, the radiation power from the antenna and the volume of lesion which the hepatic cancer was successful hepatic ablation. From these investigations, some useful results for practical treatments were found.
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Microwave ablation system design to study the effects of coaxial antenna on in-vitro animal tissue
(2014-01-01)
Chaichanyut, M.
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Lertprasert, P.
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Tungjitkusolmun, S.
This paper presents a novel low cost microwave ablation system design to study the effects of coaxial antenna on In Vitro animal tissues. The system utilizes a high-voltage power supply so that the magnetron can generate a microwave field continuously, and its output power can be adjusted from 10 - 80 W at frequency of 2.45GHz. We control output microwave power level by using control the magnetron power supply, which it is an important part of a microwave heating system. Power control of the magnetron’s power supply is desired for microwave heating to enhance performance and to provide system flexibility. The high frequency switching technique in the power supply control is costly and complicated. In another way, pulsing the output power of the magnetron can be simply realized with TRIAC, but in that case the magnetron does not operate continuously. The proposed circuit is a simple one with TRIAC. The power control is achieved by controlling the triggering events at appropriate phase angle of the household 220V. Experimental protocol was composed by a radiation system and a thermometry system. Coaxial antenna works at 2.45 GHz, power apply during experiments was 10W×8min; 20W×4min; 40W×2min and 80W×1min. Thermal sensors were placed next to the antenna at 1mm., a large number of experiments on porcine liver are carried out, the temperature distribution within the liver are measured and illustrated, for cases of different injected microwave power and ablation time. In addition, the ablation areas in cases of different input microwave powers are measured also. All these results indicate the potential validity of this system on medical treatment of liver cancer of human body.
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The modeling techniques for analyses of electromagnetic distributions and reflection coefficients for microwave ablation
(2014-01-01)
Chaichanyut, M.
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Lertprasert, P.
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Tungjitkusolmun, S.
many advantages of microwave ablation over the other ablative therapies in the field of liver tumor ablation have driven researchers to develop innovative interstitial microwave antennas to effectively treat deep seated, nonresectable hepatic tumors. A new coaxial antenna for microwave ablation therapies has been proposed in this research paper. Three dimensional Finite Element Method (FEM) has been used to design the results of the proposed antenna. Objective metrics for assessing the characteristics of helix antennas for microwave ablation by analyzing the electromagnetic field distributions and reflection coefficients for efficiency of antenna has been specified and verified for the proposed antenna, at frequency of 2.45GHz. Our simulation results, Relative permittivity at 2.45 GHz during thermal ablation. Accumulated ablation times noted on each figure to identify temporal variations. Values tended to drop quickly in all cases when temperatures reached 100 °C and continued to drop as temperature was maintained and the tissue became more dehydrated. Changes were irreversible as tissue returned to baseline temperatures. We designs the antenna matching obtained at 2.45 GHz. During thermal ablation, the reflection coefficients it can be noted that the antenna resonance shifts toward higher frequencies and the electric field distribution at the near field region changing follow the temperature variations in tumor tissue.
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Optimal monitoring point for temperature and power control in microwave ablation system by using FEM
(2012-12-01)
Pairoch, S.
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Phasukkit, P.
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Sanpanich, A.
This study presents an optimal location of monitoring point for using by PID system to control temperature and output power of hepatic cancer microwave ablation system. We investigated a relation between output power and treatment time in hepatic ablation. A simple simulation model was adapted from COMSOL FEM solver. As a preliminary, monitoring point was supposed to place at 0.5 centimeter besides ablation probe. The simulation results shown that temperature at this monitoring point is linearly related to output power and treatment time. ©2012 IEEE.

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