一种改进型针状微波辐射器的电流分布模型

本文是介绍改进型针状微波辐射器纵向电流分布的一种计算方法。该微波辐射器用来对脑瘤等癌症进行插入式热疗。它与传统到针状辐射器不同的是，其前部的外状导体被一个圆锥所替代。文中利用传输线等效模型对其编程计算，求出了沿线的电流分布，将这一结果与传统型辐射器的电流分布进行了比较，证实了纵向电流分布正如我们所期望的那样向前发生了移动，这种改变将获得热分布产生类似的前移，从而提高了针状辐射器的临床应用价值。文中给出了辐射器在不同插入深度、负载阻抗和设计尺寸下的电流分布曲线，以便在实践中对这些参数优化选择。

A Model for the Distribution of Current in Improved Interstitial Microwave Applicators for Hyperthermia

The objective of this paper is to calculate the longitudinal distribution of current produced by a kind of improved interstitial microwave applicators for hyperthermia. The microwave applicators are used to treat brain tumours implantly. Compared with traditional microwave applicators, in this applicators the exposed inner conductor is replaced by a cone. In this paper we use the equivalent transmission model of the applicators to calculate the distribution of current with a computing program. Compared with traditional applicators, we find that the distribution of current is shifted towards the tip as expectly. This change effects a similar shift of the heating pattern. The result may be of clinical importance for heating. The paper also gives the distribution of current with different insertion depths, load impedances and design size to make best choice in practical application.