Impact of Radial Heterogeneities of Biological Tissues on Dielectric Measurements

The dielectric properties of biological tissues are relevant in dosimetry studies and in radio-frequency and microwave medical applications. Broadband tissue dielectric data is commonly acquired using open-ended coaxial probe techniques. Generally, heterogeneous tissues are accurately characterised by conducting a meticulous histological analysis of the tissue types involved in the dielectric measurement. To this extent, it is fundamental to evaluate the tissue volume interrogated by the probe, also known as the probe sensing volume or histology region. In this study, early-stage experiments are presented to investigate how radial heterogeneities can impact the histology depth. The findings of this study aim to provide the basis for more accurate dielectric characterisation of heterogeneous tissues to support microwave medical device design.