Human skin permittivity determined by millimeter wave reflection measurements

Abstract

Millimeter wave reflection from the human skin was studied in the frequency range of 37-74 GHz in steps of 1 GHz. The forearm and palm data were used to model the skin with thin and thick stratum corneum (SC), respectively. To fit the reflection data, a homogeneous unilayer and three multilayer skin models were tested. Skin permittivity in the mm-wave frequency range resulted from the permittivity of cutaneous free water which was described by the Debye equation. The permittivity increment found from fitting to the experimental data was used for determination of the complex permittivity and water content of skin layers. Our approach, first tested in pure water and gelatin gels with different water contents, gave good agreement with literature data. The homogeneous skin model fitted the forearm data well. Permittivity of the forearm skin obtained with this model was close to the skin permittivity reported by others. To fit reflection from the palmar skin with a thick SC, a skin model containing at least two layers was required. Multilayer models provided better fitting to both the forearm and palmar skin reflection data. The fitting parameters obtained with different models were consistent with each other.

Millimeter wave dosimetry of human skin

“…The skin in the first model and the deepest layer in each of the other 2 models had semi-infinite thicknesses. [Alekseev and Ziskin, 2007] were also valid for the entire 30-300 GHz range.…”

“…To fit the experimental reflection data, Alekseev and Ziskin [2007] applied several multilayer skin models. The forearm and palm data were used to model the skin with thin and thick stratum corneum (SC), respectively.…”

Electromagnetic Signatures of Human Skin in the Millimeter Wave Band 80-100 GHZ

“…The levels of emissivity and reflectivity are determined by the relative complex permittivity of a medium, and these have been measured for human skin in the microwave and MMW frequency bands at specific frequencies and over limited number of participants and measurement locations by using an open ended coaxial probe in contact with the human body [22,30,[41][42][43]. Due to the limited measured data, different theoretical models are often used to predict the relative complex permittivity of the skin, such as the Cole-Cole model and Debye model [43][44][45].…”

Investigations of Sar Distributions and Temperature Elevation on Human Body at 60 GHZ With Corrugated Antipodal Linear Tapered Slot Antenna

“…EM fields depend not only on the strength and frequency of the external fields because of several dispersion mechanisms affecting human tissues, but also on the shape, size and electrical characteristics of the body and the orientation of the body in relation to the external fields [21][22][23]. EM field and its biological effects depend on the energy absorbed and the ability to heat human tissues.…”

“…The SAR and temperature vary with the parts of the body and location of the source that is exposed to the electromagnetic (EM) radiation [20]. Therefore, for better understanding the interactions between the human body and antennas with a wireless device, such as a headphone, laptops and other wireless devises at the intended position, the antennas with wireless devices need to be characterized on skin-equivalent phantom models [16,22,23]. This paper focuses on the performance analysis of SAR distributions and temperature elevation for SIW based ALTSA using EM solver tool, Ansys's HFSS and experiments with Infrared Thermal Camera.…”