Broadband tissue mimicking phantoms and a patch resonator for evaluating noninvasive monitoring of blood glucose levels

Tissue mimicking phantoms (TMPs) replicating the dielectric properties of wet skin, fat, blood, and muscle tissues for the 0.3 to 20 GHz frequency range are presented in this paper. The TMPs reflect the dielectric properties with maximum deviations of 7.7 units and 3.9 S/m for relative dielectric constant and conductivity, respectively, for the whole band. The dielectric properties of the blood mimicking material are further investigated by adding realistic glucose amounts and a Cole-Cole model used to compare the behavior with respect to changing glucose levels. In addition, a patch resonator was fabricated and tested with the four-layered physical phantom developed in house. It was observed that the input impedance of the resonator is sensitive to the changes in the dielectric properties and, hence, to the realistic glucose level changes in the blood layer.