Shape optimization of the multi-slot coaxial antenna for local hepatic heating during microwave ablation

In this study, a thin coaxial antenna for microwave ablation (MWA) is proposed. A helical slot is added between two slots in order to overcome the disadvantage of the radiation range extending to the unwanted part in the conventional single-slot and double-slot applicators. By adding a helical slot, the specific absorption rate (SAR) pattern is more concentrated near the slot as compared with the conventional slot. Experiments were conducted using the simulation, and a liver phantom was made and heated up using microwaves. Based on the results on the liver phantom, experiments were conducted using swine liver which is similar to human liver. Applied frequency and microwave average input power were assumed as 2.45 GHz and 50 W (47 dBm), respectively. As a result of the experiment, return loss was −23.09 dB, and the temperature reached 60°C after 90 seconds of exposition. Based on the phantom experiments of the swine liver, necrotic lesions of the tissue at a distance of 3.5–4 cm from the microwave antenna were observed.

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“…e Pennes bio-heat equation effectively describes how heat transfer occurs in biological tissue [19]:…”

Section: Physical Principlesmentioning

confidence: 99%

Helical Slot Antenna for the Microwave Ablation

Lee

Son

2019

International Journal of Antennas and Propagation

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“…This frequency is part of the industrial, scientific, and medical band provided by the International Telecommunication Union, which is available worldwide for medical applications. Using this frequency, the effective wavelength in the tissue was calculated by means of the following equation [ 28 ]:

…”

Section: Methodsmentioning

confidence: 99%

Computational FEM Model and Phantom Validation of Microwave Ablation for Segmental Microcalcifications in Breasts Using a Coaxial Double-Slot Antenna

Félix

Guerrero

Rubio

et al. 2021

BioMed Research International

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Introduction. Cancer is the second leading cause of death worldwide. Breast cancer is the second most common cause of cancer-related mortality, accounting for 11.6% of the total number of deaths. The main treatments for this disease are surgical removal of the tumor, radiotherapy, and chemotherapy. Recently, different minimally invasive technologies have been applied (e.g., emission of electromagnetic waves, thermal and chemical means) to overcome the important side effects of these treatment modalities. The objective of this study was to develop and evaluate a predictive computational model of microwave ablation. Materials and Methods. The predictive computational model of microwave ablation was constructed by means of a dual-slot coaxial antenna. The model was compared with an experiment performed using a breast phantom, which emulates the dielectric properties of breast tissue with segmental microcalcifications. The standing wave ratio (SWR) was obtained for both methods to make a comparison and determine the feasibility of applying electromagnetic ablation to premalignant lesions in breasts. Specifically, for the analysis of segmental microcalcifications, a breast phantom with segmental microcalcifications was developed and two computational models were performed under the same conditions (except for blood perfusion, which was excluded in one of the models). Results. The SWR was obtained by triplicate experiments in the phantom, and the measurements had a difference of 0.191 between the minimum and maximum SWR values, implying a change of power reflection of 0.8%. The average of the three measurements was compared with the simulation that did not consider blood perfusion. The comparison yielded a change of 0.104, representing a 0.2% change in power reflection. Discussion. Both experimentation in phantom and simulations demonstrated that ablation therapy can be performed using this antenna. However, an additional optimization procedure is warranted to increase the efficiency of the antenna.

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“…As we have observed, little variations in the aforementioned parameters result in significant variances in the time–temperature characteristics acquired for the numerical results. As a result, we propose employing the optimization method to accurately predict the model’s selected physical parameters [ 45 , 46 , 47 ].…”

Section: Numerical Modelmentioning

confidence: 99%

An Evaluation of 3D-Printed Materials’ Structural Properties Using Active Infrared Thermography and Deep Neural Networks Trained on the Numerical Data

Szymanik

2022

Materials

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This article describes an approach to evaluating the structural properties of samples manufactured through 3D printing via active infrared thermography. The mentioned technique was used to test the PETG sample, using halogen lamps as an excitation source. First, a simplified, general numerical model of the phenomenon was prepared; then, the obtained data were used in a process of the deep neural network training. Finally, the network trained in this manner was used for the material evaluation on the basis of the original experimental data. The described methodology allows for the automated assessment of the structural state of 3D−printed materials. The usage of a generalized model is an innovative method that allows for greater product assessment flexibility.

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Shape optimization of the multi-slot coaxial antenna for local hepatic heating during microwave ablation

Cited by 10 publications

References 15 publications

Helical Slot Antenna for the Microwave Ablation

Helical Slot Antenna for the Microwave Ablation

Computational FEM Model and Phantom Validation of Microwave Ablation for Segmental Microcalcifications in Breasts Using a Coaxial Double-Slot Antenna

An Evaluation of 3D-Printed Materials’ Structural Properties Using Active Infrared Thermography and Deep Neural Networks Trained on the Numerical Data

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