Abstract:
:Recent studies of the minute morphology of the skin by optical coherence tomography revealed that the sweat ducts in human skin are helically shaped tubes, filled with a conductive aqueous solution. This, together with the fact that the dielectric permittivity of the dermis is higher than that of the epidermis, brings forward the supposition that as electromagnetic entities, the sweat ducts could be regarded as low Q helical antennas. The implications of this statement were further investigated by electromagnetic simulation and experiment of the in vivo reflectivity of the skin of subjects under varying physiological conditions (Feldman et al 2008 Phys. Rev. Lett. 100 128102). The simulation and experimental results are in a good agreement and both demonstrate that sweat ducts in the skin could indeed behave as low Q antennas. Thus, the skin spectral response in the sub-Terahertz region is governed by the level of activity of the perspiration system and shows the minimum of reflectivity at some frequencies in the frequency band of 75-110 GHz. It is also correlated to physiological stress as manifested by the pulse rate and the systolic blood pressure. As such, it has the potential to become the underlying principle for remote sensing of the physiological parameters and the mental state of the examined subject.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Feldman Y,Puzenko A,Ben Ishai P,Caduff A,Davidovich I,Sakran F,Agranat AJdoi
10.1088/0031-9155/54/11/005subject
Has Abstractpub_date
2009-06-07 00:00:00pages
3341-63issue
11eissn
0031-9155issn
1361-6560pii
S0031-9155(09)01713-8journal_volume
54pub_type
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