Broadband Dielectric Spectroscopy of biological tissues: fundamental aspects and new perspectives

This chapter deals with dielectric spectroscopy of biological tissues. The knowledge of tissue dielectric properties has been the subject of research since about a century, when the first applications of electromagnetic fields began to be developed. Great impulse was given around the 1990s, when cellular phones went into use and concerns raised about possible adverse effects of electromagnetic fields. At the time, a thorough study was developed, in which the dielectric properties of biological tissues were measured in a broad frequency range (Gabriel et al., 1996a, 1996b, 1996c). The importance of the study by Gabriel et al. resides not only in its scientific rigor, but also in the fact that the measured results were uploaded on the web to be at disposal to all researchers involved in the studies of the interaction between electromagnetic fields and the human body (https://www.fcc.gov/general/body-tissue-dielectric-parameters; last accessed on 4 September, 2024). The information is still on the web mirrored in different websites (http://niremf.ifac.cnr.it/tissprop, https://itis.swiss/virtual-population/tissue-properties/database/dielectric-properties; last accessed on 4 September, 2024). Since then, several other research groups were involved in the measurement of dielectric properties of biological tissues, trying to control all possible measurement confounders as, for example, the temperature and sample handling (Farrugia et al., 2024).