Investigation on the effect of dehydration on tissue dielectric properties in the ex-vivo measurements

This paper discusses the impact of tissue dehydration on the dielectric properties of excised tissue sample. The effect of dehydration on tissue surface has been characterized as a function of time after excision on freshly excised mice liver. The dielectric properties of liver were measured over the frequency range of 500 MHz to 20 GHz using an open-ended coaxial probe. Tissue samples were obtained from 7 athymic BALB c Nude mice, and measurements were performed over first 3.5-hours post-excision at the surface of tissue and in the middle of the sample with small incision. The samples were kept in sealed containers between the measurements to avoid excessive dehydration. The measured dielectric data show a change of more than 25% in both the real and imaginary parts of complex permittivity over 3.5 hours after excision. Results indicate the impact of tissue dehydration on the dielectric properties, and signify the importance of controls to be considered in experimental design of the ex-vivo dielectric measurements.