title: Empirical and theoretical dosimetry in support of whole body resonant RF exposure (100 MHz) in human volunteers.
abstract: This study reports the dosimetry performed to support an experiment that measured physiological responses of volunteer human subjects exposed to the resonant frequency for a seated human adult at 100 MHz. Exposures were performed in an anechoic chamber which was designed to provide uniform fields for frequencies of 100 MHz or greater. A half wave dipole with a 90 degrees reflector was used to optimize the field at the subject location. The dosimetry plan required measurement of transmitter harmonics, stationary probe drift, field strengths as a function of distance, electric and magnetic field maps at 200, 225, and 250 cm from the dipole antenna, and specific absorption rate (SAR) measurements using a human phantom, as well as theoretical predictions of SAR with the finite difference time domain (FDTD) method. On each exposure test day, a measurement was taken at 225 cm on the beam centerline with a NBS E field probe to assure consistently precise exposures. A NBS 10 cm loop antenna was positioned 150 cm to the right, 100 cm above, and 60 cm behind the subject and was read at 5 min intervals during all RF exposures. These dosimetry measurements assured accurate and consistent exposures. FDTD calculations were used to determine SAR distribution in a seated human subject. This study reports the necessary dosimetry for work on physiological consequences of human volunteer exposures to 100 MHz.
authors.affiliation: Veridian Engineering, Brooks City Base, Texas 78235, USA. stewart.allen@brooks.af.mil
authors.forename: Stewart J
authors.initials: SJ
authors.lastname: Allen
authors.forename: Eleanor R
authors.initials: ER
authors.lastname: Adair
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Mylacraine
authors.forename: William
authors.initials: W
authors.lastname: Hurt
authors.forename: John
authors.initials: J
authors.lastname: Ziriax
mesh_terms: D000328:Adult; D003198:Computer Simulation; D006801:Humans; D008297:Male; D008954:Models, Biological; D011829:Radiation Dosage; D011846:Radio Waves; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014915:Whole-Body Counting / Q000295:instrumentation* / Q000379:methods*; D014916:Whole-Body Irradiation / Q000379:methods*