Planar microwave sensor for thermal ablation of organic tissue

A novel dual mode sensor prototype using a planar structure based on split ring resonators is presented. It features two distinct operation modes, first for sensing dielectric properties of organic tissue and second for performing thermal ablation therapy. It is designed for detection of spatially distributed dielectric inhomogeneities and a controllable heating of localized regions for thermal ablation. This combination enables the localization and selective ablation of cancerous tissue. Considering the clinical use for cancer treatment, the tool is designed to be included in a minimal invasive instrument. In addition, phantoms of organic tissue are fabricated and characterized in the microwave region. It is shown that by a simple variation of the concentration of a single ingredient the properties of various tissues can be mimicked. Measurements of the prototype with these phantoms are presented and different temperature measurement methods are used for verification of the local heating capability for ablation purposes. The prototype creates a focused hot spot with a temperature of 60 °C at an input power of 5W.