The Effect of Slot Sizes on Non-Asymmetry Slot Antennafor Microwave Coagulation Therapy

Wongtrairat, Wannaree; Phasukkit, Pattarapong; Tungjitkusolmun, S.; Nantivatana, Petch

doi:10.7763/ijbbb.2011.v1.35

Cited by 3 publications

(1 citation statement)

References 22 publications

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“…MWA is achieved by microwave coaxial antennas (MCA), which operates at 2.45 GHz and can transmit high power into the cancerous tissue [5]. MCAs, such as monopole [6], dipole [7], slot [8,9], and triaxial [10] are preferred in MWA due to their properties such as easy to design and low return loss [11]. Although MCAs are successful in eradicating the tumor, they exhibit backward heating phenomenon along the antenna, hence they cause damage to the healthy tissue, which is one of the serious problems limiting the use of microwaves as an ablation technique.…”

Section: Introductionmentioning

confidence: 99%

Graphene-based microwave coaxial antenna for microwave ablation: thermal analysis

Uzman

Yilmaz

Acikgoz

et al. 2020

Int. J. Microw. Wireless Technol.

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In this study, the problem of backward heating in microwave ablation technique is examined and an electromagnetic solution based on the use of high impedance graphene material is presented for its mitigation. In this context, a one-atom-thick graphene layer is added on the coaxial double slot antenna. In addition to the electromagnetic behavior, thermal effects caused by the graphene-covered antenna are emphasized. The graphene's conductivity being highly dependent on its chemical potential and the relaxation time, a parametric study is performed to determine a range of tolerances within which the graphene-coated antenna outperform a typical graphene-free antenna. The range of values is found to be 0 < μ c < 0.5 eV and τ < 0.4 ps, for the chemical potential and the relaxation time, respectively. The backward heating problem being prevented, the ablation region is ensured to be spherical around the tip of the antenna. Effects of the graphene layer to the heat dissipation in the tissue, the necrotic tissue ratio (damage to the cancerous tissue of the caused by electromagnetic energy), and the treatment time using the coaxial double slot antenna were examined. The results show that the heat dissipation is concentrated around the slots (region of cancerous tissue) and a higher necrotic tissue ratio can be achieved with a graphene-covered double slot antenna in a shorter time.

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Section: Introductionmentioning

confidence: 99%

Graphene-based microwave coaxial antenna for microwave ablation: thermal analysis

Uzman

Yilmaz

Acikgoz

et al. 2020

Int. J. Microw. Wireless Technol.

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Triple Coaxial-Half-Slot Antenna Scheme With Deep Learning-Based Temperature Prediction for Hepatic Microwave Ablation: Finite Element Analysis and In Vitro Experiment

Phasukkit

Wongketsada

2021

IEEE Access

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This research proposes a triple-antenna scheme of three coaxial half slot antennas (CHSA) for minimally invasive hepatic microwave ablation (MWA). In the MWA treatment, the antennas were positioned around the cancer tissue in equilateral triangle formation, with the half-slot side of the antennas directed at the triangle center to concentrate the microwave energy. Finite element (FE) simulations and in vitro experiments with swine liver were carried out to determine the temperatures and coagulation zone under different distances between the three antennas: 10, 20, and 30 mm. Besides, a regression-based deep learning algorithm was utilized to predict temperatures at the midpoint of the triple-CHSA arrangement without inserting a temperature sensor into the targeted tissue. The algorithm relied on temperatures at a site adjacent to the targeted cancer tissue to predict the midpoint temperatures. The triple-CHSA scheme could achieve a large coagulation zone with temperatures of 60 °C or higher. The FE simulation results showed that the largest coagulation volumes achieved were 18.425, 29.312, and 63.507 cm3 for the between-antenna distances of 10, 20, and 30 mm, respectively. The largest coagulation volumes of in vitro experiments were 18.437, 29.317, and 63.504 cm3 for the corresponding between-antenna distances. The prediction accuracy of the deep learning algorithm were 99.98 % for mean square error, 98.75 % for mean absolute error, and 99.22 % for mean absolute percentage error. The novelty of the research lies in the use of CHSA surrounding the cancer tissue in equilateral triangle formation for hepatic MWA, as opposed to the conventional hepatic MWA procedure which requires inserting antennas into the targeted tissue. Another research novelty is the use of regression-based deep learning algorithm to predict the temperature of liver tissue at the midpoint of the triple-CHSA arrangement.INDEX TERMS triple antenna, microwave (MA) ablation, Coaxial-half-slot Antenna, temperature prediction, finite element (FE) analysis, In Vitro experiment, directional

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Numerical Investigation of Tissue Heating with Coaxial Slot Antenna Using Microwave Heater

Türkan

2022

EJOSAT

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In hyperthermic oncology, the disease is treated by applying localized heating to the tumor, usually in combination with chemotherapy or radiotherapy. Heating is provided to the tumor from the part where a thin microwave antenna is placed. Here, a coagulated area is produced where cancer cells are killed. In this study, the temperature change, tissue deformation and specific absorption rate (SAR) of the tissue under the microwave effect were calculated. The liver tissue was modeled with a coaxial slot antenna at a frequency of 2.45 GHz and a numerical solution was made in the Comsol program. Result simulations of tissue after 2-4 and 6 minutes were obtained by taking different microwave powers (10-20-30W). It has been seen that the results obtained are compatible with the literature information.

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The Effect of Slot Sizes on Non-Asymmetry Slot Antennafor Microwave Coagulation Therapy

Cited by 3 publications

References 22 publications

Graphene-based microwave coaxial antenna for microwave ablation: thermal analysis

Graphene-based microwave coaxial antenna for microwave ablation: thermal analysis

Triple Coaxial-Half-Slot Antenna Scheme With Deep Learning-Based Temperature Prediction for Hepatic Microwave Ablation: Finite Element Analysis and In Vitro Experiment

Numerical Investigation of Tissue Heating with Coaxial Slot Antenna Using Microwave Heater

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