Variability of the Dielectric Properties Due to Tissue Heterogeneity and Its Influence on the Development of EM Phantoms

Electromagnetic phantoms are either software tools or physical materials that emulate the dielectric properties of biological tissues. Among them, muscle, fat and skin phantoms are some of the most used ones. For their proper development, careful knowledge of the dielectric properties of their respective real tissues is required. In general, the data of a measurement campaign-Gabriel's database generally - are used as target reference values, without considering their variability due to issues such as tissue heterogeneity, sample condition or subject's age. These aspects may have a significant impact in the range of the values of the dielectric properties, and thus using just their mean values may not be the best choice for all kinds of experiments. In this paper, the variability of the in vivo dielectric properties of abdominal tissues such as muscle, fat, skin, stomach serosa, small intestine serosa and colon serosa due to their heterogeneity is presented. For this purpose, a measurement campaign has been performed on 3 different porcine subjects using the open-ended coaxial method in the 0.5–26.5 GHz frequency band. Several measurements were driven in different tissue locations of each specimen. The mean values are compared to in vivo measurements presented in literature so far, whereas possible implications of tissue heterogeneity for developing phantoms for certain applications are briefly discussed.

[1]  J. Schwartz,et al.  Dielectric properties of frog tissues in vivo and in vitro. , 1985, Physics in medicine and biology.

[2]  John H. Booske,et al.  Sensing volume of open-ended coaxial probes for dielectric characterization of breast tissue at microwave frequencies , 2003 .

[3]  T. Tamura,et al.  Modelling of the dielectric properties of normal and irradiated skin. , 1994, Physics in medicine and biology.

[4]  E. C. Burdette,et al.  In Vivo Probe Measurement Technique for Determining Dielectric Properties at VHF through Microwave Frequencies , 1980 .

[5]  C. Gabriel.  Compilation of the Dielectric Properties of Body Tissues at RF and Microwave Frequencies. , 1996 .

[6]  C. Gabriel,et al.  Variation of the dielectric properties of tissues with age: the effect on the values of SAR in children when exposed to walkie–talkie devices , 2009, Physics in medicine and biology.

[7]  Sverre Grimnes,et al.  INTERFACE PHENOMENA AND DIELECTRIC PROPERTIES OF BIOLOGICAL TISSUE , 2002 .

[8]  M. Stuchly,et al.  In vivo and in vitro dielectric properties of animal tissues at radio frequencies. , 1982, Bioelectromagnetics.

[9]  Alejandro Fornes-Leal,et al.  Accurate broadband measurement of electromagnetic tissue phantoms using open-ended coaxial systems , 2017, 2017 11th International Symposium on Medical Information and Communication Technology (ISMICT).

[10]  C Gabriel,et al.  Dielectric measurement: error analysis and assessment of uncertainty , 2006, Physics in medicine and biology.

[11]  Glenn Hefter,et al.  Dielectric relaxation of aqueous NaCl solutions , 1999 .

[12]  M A Stuchly,et al.  Dielectric properties of animal tissues in vivo at radio and microwave frequencies: comparison between species. , 1982, Physics in medicine and biology.