Morphology of human sweat ducts observed by optical coherence tomography and their frequency of resonance in the terahertz frequency region.

Saroj R Tripathi,Eisuke Miyata,Kodo Kawase,Paul Ben Ishai

doi:10.1038/srep09071

Saroj R Tripathi, Eisuke Miyata + Show 2 more

Open Access

https://doi.org/10.1038/srep09071

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Abstract

It is crucial to understand the various biological effects induced by terahertz (THz) electromagnetic waves with the rapid development of electronic and photonic devices operating in the THz frequency region. The presence of sweat glands plays an important role in THz wave interactions with human skin. We investigated the morphological features of sweat ducts using optical coherence tomography (OCT) to further understand such phenomena. We observed remarkable features of the ducts, such as their clear helical structure. The intersubject and intrasubject variations in the diameter of sweat ducts were considerably smaller than the variations in other structural parameters, such as length and number of turns. Based on the sweat duct dimensions and THz dielectric properties of skin measured using terahertz time-domain spectroscopy (THz-TDS), we calculated the resonating frequency of the sweat duct under the assumption of it functioning as a helical antenna. Here, we show that the resonance frequency in the axial mode of operation lies in the THz wave region with a centre frequency of 0.44 ± 0.07 THz. We expect that these findings will further our understanding of the various health consequences of the interaction of THz waves with human beings.

Highlights

Morphology of human sweat ducts observed by optical coherence tomography and their frequency of resonance in the terahertz frequency region
We investigated the morphological features of sweat ducts using optical coherence tomography (OCT) to further understand such phenomena
Based on the sweat duct dimensions and THz dielectric properties of skin measured using terahertz time-domain spectroscopy (THz-TDS), we calculated the resonating frequency of the sweat duct under the assumption of it functioning as a helical antenna

Summary

Introduction

Morphology of human sweat ducts observed by optical coherence tomography and their frequency of resonance in the terahertz frequency region. Other studies on THz-induced non-thermal effects suggest genomic instability[19], mutagenesis[20], DNA synthesis[21], spindle disturbances in cells[22] and stem cell reprogramming[23] Besides such studies on thermal and non-thermal effects induced by THz radiation, recently novel phenomena of skin-THz interaction have been reported. These studies have demonstrated that sweat glands present in the www.nature.com/scientificreports skin play a critical role in THz wave interaction with human beings. Sweat duct dimensions, density and distribution as well as the dielectric properties of the stratum corneum are crucial in determining the resonating frequency range, which will enable further insight into THz wave interactions with human beings

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