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 permit-tivity from superficial measurements on fat, thereby proving the feasibility of DPA in the biological domain for enhancing measurement specificity.