Abd Rahman Amirah, Kamardin Kamilia, Yamada Yoshihide, Takahashi Masaharu
Department of Electronic Systems Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia.
Wireless Communication Centre, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia.
Heliyon. 2024 Mar 15;10(6):e28061. doi: 10.1016/j.heliyon.2024.e28061. eCollection 2024 Mar 30.
In radio wave hyperthermia therapy, array antenna configuration was mainly studied to generate a small spot at the diseased part. Array antennas have the flexibility in controlling radiation performance, such as spot positions, by using their numerous radiating elements. However, the flexibility is achieved at the expense of antenna structure complexity. On the other hand, a lens antenna can concentrate radio waves into a small spot by forming a lens shape. The simplicity of a lens antenna structure lends itself to easy handling in a practical application. Moreover, the frequency independence of the lens antenna allows for a more flexible selection of hyperthermia therapy frequencies. Therefore, the lens antenna is selected as a focusing antenna in this paper. The lens shaping method and the temperature increment measurement are the main contents of this paper. The designed lens has a diameter of 30 cm, a focusing distance of 30 cm, and a working frequency of 2.45 GHz. A thin lens design method is applied to reduce lens weight. Firstly, the focusing ability of the designed lens is ensured by comparing the spot size results of electromagnetic (EM) simulation with its theoretical value. A spot size of 1.77 cm is obtained in both cases. Next, the temperature increment is examined by EM simulations. The temperature at the 2 cm tumor was increased to 41 °C from the human body temperature of 37 °C by an input power of 10 Watts (W). For the temperature increment measurement, a tumor within human body phantom is utilized and the available input power is reduced to 4 W. The tumor temperature increased from 21.5 °C of room temperature to 24.4 °C, which was captured by a thermal imaging camera. As a result, the functionality of the lens antenna for hyperthermia therapy is verified.
在射频热疗中，主要研究阵列天线配置以在病变部位产生小光斑。阵列天线通过使用其众多辐射元件，在控制辐射性能（如光斑位置）方面具有灵活性。然而，这种灵活性是以天线结构复杂性为代价实现的。另一方面，透镜天线可以通过形成透镜形状将无线电波集中到一个小光斑中。透镜天线结构的简单性使其在实际应用中易于操作。此外，透镜天线的频率独立性允许更灵活地选择热疗频率。因此本文选择透镜天线作为聚焦天线。透镜成形方法和温度增量测量是本文的主要内容。所设计的透镜直径为30厘米，焦距为30厘米，工作频率为2.45吉赫兹。应用薄透镜设计方法来减轻透镜重量。首先，通过将电磁（EM）模拟的光斑尺寸结果与其理论值进行比较，确保所设计透镜的聚焦能力。在两种情况下均获得了1.77厘米的光斑尺寸。接下来，通过EM模拟检查温度增量。通过10瓦（W）的输入功率，将2厘米肿瘤处的温度从人体温度37°C升高到41°C。对于温度增量测量，使用人体模型内的肿瘤，并将可用输入功率降低到4W。肿瘤温度从室温21.5°C升高到24.4°C，这由热成像相机捕获。结果，验证了透镜天线用于热疗的功能。
