Keynote speech 3: Recent medical applications of electromagnetic waves

Recently, various types of medical applications of electromagnetic waves have widely been investigated and reported. Typical recent medical applications include: (1) Information / Wireless power transfer: - Wearable or implantable vital data sensor / monitor - Wireless telemedicine / Mobile health system using IoT (Internet of Things) - Wireless capsule endoscopy (2) Diagnosis: - High intensity MRI (Magnetic Resonance Imaging) - Microwave CT (Computed Tomography) for cancer detection - Wireless sleep monitor / ECG (electrocardiogram) monitor (3) Treatment: - Thermal therapy (hyperthermia, ablation, etc) - Wireless brain stimulator - Surgical device (coagulation device, microwave knife, etc) In this presentation, some practical medical applications of electromagnetic waves are introduced. Firstly, a wearable dual-mode antenna for vital data monitoring systems is presented. A key technology for the antenna is body-centric wireless communications. Secondly, an X-band antenna for a microwave sleep monitor is demonstrated with human-body phantom experiments. A “dynamic” phantom played an important role for the study. Thirdly, a coaxial-slot antenna and an array applicator composed of several coaxial-slot antennas for minimally invasive microwave thermal therapy are overviewed. A few results of actual clinical trials by use of coaxial-slot antennas are demonstrated from a technical point of view. Finally, a few different types of surgical devices using high power microwave energy are introduced. Heating characteristics of such microwave surgical devices are evaluated by numerical calculation as well as experiments using phantoms, meat and animals. In addition, some future works are briefly discussed.