Sensing Depth Analysis of Open-Ended Coaxial Probe for Skin Cancer Detection

Inherent dielectric properties discrepancy between different tissues have long been of interest to researchers in order to improve medical diagnostic approaches and therapeutic technologies. Hence, determination of the dielectric properties for biological tissues is keystone to develop an innovative medical system. Widely, the dielectric properties of biological tissues have been determined by utilizing slim form open-ended probes. Although, the method is superior to other dielectric property measurement techniques in several aspects, the measurement procedure suffers from equipment-related and tissue-related errors. Sensing depth, which is one of the confounders can be associated with both equipment and tissue-related errors. In this work, we performed the preparation of skin mimicking phantom and conducted a series of experiments on a two-layer configuration consisting of the prepared phantom and a liquid (olive oil). Furthermore, the sensing depth of the 2.2mm aperture open-ended coaxial probe was analyzed at five different frequencies. The results obtained show that the sensing depth of biological tissues strongly depends on the operation frequency. We also observed that the sensing depth decreases at higher frequencies and this is a property can be utilized in tackling thin multi-layered structures problem such as skin cancer detection.