Enhancing Measurement Specificity in Biological Samples with Differential Probing Analysis

Developing integrated sensors for unobtrusive in-vivo biomarker analysis is strongly desired. Various sensor designs have been created to detect permittivity variations related with biomedical processes at microwave frequencies. However, achieving measurement specificity remains a challenge due to complex biological tissues and electromagnetic field scattering. To address this challenge, in our previous work, we introduced differential probing analysis (DPA). DPA involves the use of open-ended coaxial probes (OCP) of different sizes and was validated for low-permittivity and low-loss samples. In this work, experimental findings on pork neck chop samples demonstrate the accurate determination of underlying muscle tissue permittivity from superficial measurements on fat, thereby proving the feasibility of DPA in the biological domain for enhancing measurement specificity.