Record Display for the EPA National Library Catalog


Main Title Measurement of Small Mechanical Vibrations of Brain Tissue Exposed to Extremely-Low-Frequency Electric Fields.
Author Spiegel, R. J. ; Ali, J. S. ; Peoples, J. F. ; Joines, W. T. ;
CORP Author Health Effects Research Lab., Research Triangle Park, NC.
Year Published 1986
Report Number EPA/600/J-86/190;
Stock Number PB87-145512
Additional Subjects Electric fields ; Brain ; Tissues(Biology) ; Vibrations ; Exposure ; Measurement ; Reprints ; Extremely low frequency
Library Call Number Additional Info Location Last
NTIS  PB87-145512 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 14p
Electromagnetic fields can interact with biological tissue both electrically and mechanically. This study investigated the mechanical interaction between brain tissue and an extremely-low-frequency (ELF) electric field by measuring the resultant vibrational amplitude. The exposure cell is a section of X-band waveguide that was modified by the addition of a center conductor to form a small TEM cell within the waveguide structure. The ELF signal is applied to the center conductor of the TEM cell. The applied ELF electric field generates an electrostrictive force on the surface of the brain tissue. This force causes the tissue to vibrate at a frequency equal to twice the frequency of the applied sinusoidal signal. An X-band signal is fed through the waveguide, scattered by the vibrating sample, and detected by a phrase-sensitive receiver. Using a time-averaging spectrum analyzer, a vibration sensitivity of approximately 0.2 nmpp can be achieved. The amplitude of the brain tissue vibrational frequencies below 50 Hz; between 50 and 200 Hz resonant phenomena were observed; and above 200 Hz the amplitude fall-off is rapid.