Keynote 2: Microwave antennas for medical applications

In recent years, various types of medical applications of antennas have widely been investigated and reported. Typical recent applications are in Information transmission such as RFID (radio frequency identification)/wearable or implantable monitor and wireless telemedicine/mobile health system and in diagnosis such as MRI (magnetic resonance imaging)/fMRI and microwave CT (computed tomography)/radiometry. Other application includes in treatment such as thermal therapy (Hyperthermia, Coagulation, etc) and microwave knife. In this presentation, three different types of antennas which have been studied in our laboratory are introduced. Firstly, a pretty small antenna for an implantable monitoring system is presented. An H-shaped cavity slot antenna is a candidate for such a system. Some numerical and experimental characteristics of the antenna are demonstrated. Secondly, some different antennas or ldquoRF coilsrdquo for MRI systems are introduced. In addition, SAR (specific absorption rate) distributions in the abdomen of a pregnant woman generated in a bird cage coil are illustrated. Finally, after a brief overview of thermal therapy and microwave heating, coaxial-slot antennas and array applicators composed of several coaxial-slot antennas for minimally invasive microwave thermal therapies are introduced. Then a few results of actual clinical trials by use of the coaxial-slot antennas are demonstrated from a technical point of view. Other therapeutic applications of the coaxial-slot antennas such as hyperthermic treatment for brain tumor and intracavitary hyperthermia for bile duct carcinoma are introduced.