Share Email Print

Proceedings Paper

Terahertz imaging and international safety guidelines
Author(s): Gillian Claire Walker; Elizabeth Berry; Nick N. Zinov'ev; Anthony J. Fitzgerald; Robert E. Miles; J. Martyn Chamberlain; Michael A. Smith
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Terahertz (THz) radiation has a frequency of the order of 101212 Hz. This lies between the infrared and microwave regions of the electromagnetic spectrum; a section labeled the 'THz gap'. Infrared and microwave radiation is used in the medical field; research is underway for an application for THz radiation. At present no formal safety analysis of a THz pulsed imaging (TPI) system has been performed. This will be necessary for future in vivo studies. The radiation is delivered in a train of femtosecond pulses. International guidelines on exposure to non-ionizing radiation, and supporting literature, were reviewed to determine the Maximum Permissible Exposure (MPE) for radiation of this range of wavelengths, both for a single pulse and continuous wave exposure. Two methods of deriving the MPE were identified. Current guidelines for infrared and microwave regions of the electromagnetic spectrum incorporate the THz region. Using conservative parameter estimation an MPE per pulse, over the area of the beam, of 94 W was calculated. At present THz pulsed imaging systems produce pulses of power approximately 1 mW; this lies within the limit calculated using the published guidelines. There are, however, areas requiring further investigation before the technique becomes routine in clinical practice.

Paper Details

Date Published: 3 May 2002
PDF: 8 pages
Proc. SPIE 4682, Medical Imaging 2002: Physics of Medical Imaging, (3 May 2002); doi: 10.1117/12.465614
Show Author Affiliations
Gillian Claire Walker, Univ. of Leeds (United Kingdom)
Elizabeth Berry, Univ. of Leeds (United Kingdom)
Nick N. Zinov'ev, Univ. of Leeds (United Kingdom)
Anthony J. Fitzgerald, Univ. of Leeds (United Kingdom)
Robert E. Miles, Univ. of Leeds (United Kingdom)
J. Martyn Chamberlain, Univ. of Leeds (United Kingdom)
Michael A. Smith, Univ. of Leeds (United Kingdom)

Published in SPIE Proceedings Vol. 4682:
Medical Imaging 2002: Physics of Medical Imaging
Larry E. Antonuk; Martin Joel Yaffe, Editor(s)

© SPIE. Terms of Use
Back to Top