Department of Information Engineering, Electronics, and Telecommunications, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy.
Institute for Microwave Engineering and Photonics, Technische Universität Darmstadt, Merckstr. 25, 64283 Darmstadt, Germany.
Sensors (Basel). 2023 Feb 26;23(5):2579. doi: 10.3390/s23052579.
Microwave ablation is a technique used to treat tumorous tissue. Its clinical use has been greatly expanding in the last few years. Because the design of the ablation antenna and the success of the treatment greatly depend on the accurate knowledge of the dielectric properties of the tissue being treated, it is highly valuable to have a microwave ablation antenna that is also able to perform in-situ dielectric spectroscopy. In this work, an open-ended coaxial slot ablation antenna design operating at 5.8 GHz is adopted from previous work, and its sensing abilities and limitations are investigated in respect of the dimensions of the material under test. Numerical simulations were performed to investigate the functionality of the floating sleeve of the antenna and to find the optimal de-embedding model and calibration option for obtaining accurate dielectric properties of the area of interest. Results show that, as in the case of the open-ended coaxial probe, the accuracy of the measurement greatly depends on the likeness between the calibration standards' dielectric properties and the material under test. Finally, the results of this paper clarify to which extent the antenna can be used to measure dielectric properties and paves the way to future improvements and the introduction of this functionality into microwave thermal ablation treatments.
微波消融是一种用于治疗肿瘤组织的技术。在过去的几年中，它的临床应用得到了极大的扩展。由于消融天线的设计和治疗的成功在很大程度上取决于对所治疗组织的介电特性的准确了解，因此拥有能够进行原位介电光谱测量的微波消融天线具有很高的价值。在这项工作中，采用了先前工作中 5.8GHz 工作的开放式同轴缝隙消融天线设计，并针对测试材料的尺寸研究了其传感能力和局限性。数值模拟用于研究天线浮动套筒的功能，并找到用于获得感兴趣区域的准确介电特性的最佳去嵌入模型和校准选项。结果表明，与开放式同轴探头一样，测量的准确性在很大程度上取决于校准标准的介电特性与测试材料的相似性。最后，本文的结果阐明了天线可以在多大程度上用于测量介电特性，并为未来的改进和将此功能引入微波热消融治疗铺平了道路。
