Design and characterisation of a broadband PCB coaxial sensor for non-invasive skin cancer analysis

Biological tissues exhibit varying dielectric properties depending on their composition and physiological state. Broadband dielectric spectroscopy is a valuable non-destructive diagnostic tool for biomedical applications such as glucose monitoring, hydration level detection, and cancer tissue analysis. In the case of melanoma, researches have shown that skin permittivity level varies at the lesion site. Detecting tumors therefore requires imaging the complex permittivity of suspicious areas with a spatial resolution compatible with the small dimensions of these surfaces. However, developing a sensitive sensor capable of detecting small permittivity variations is challenging due to the variability of skin properties for different people and physiological states (e.g. temperature, humidity). This paper presents the design of an innovative detection sensor that can accurately detect variations in cutaneous permittivity between 1 and 6 GHz to identify different types of tumors in their early stage with a good agreement between simulated and measured results.