Formulation and Characterization of Tissue Equivalent Liquids Used for RF Densitometry and Dosimetry Measurements

Abstract

It is possible to accurately predict the dielectric parameters (effective permittivity and equivalent conductivity) of tissue equivalent liquids as a function of formulation across a range of radio frequencies. The prediction is based on the dielectric characterization of a set of parametric liquids of known formulation across certain frequency bands. Simple interpolation is used to predict the dielectric characteristics of the formulations between the parametric liquids. This evaluation can be used to predict the formulation meeting specific dielectric parameters or provide direction when trying to correct a liquid that has drifted out of specification. This technique was used to determine the sugar and di-ethylene-glycol-butyl-ether-based formulations found in the IEEE 1528 Standard. The same technique can be used to characterize other parameters of the liquids such as their density and specific heat capacity.