Study type: Medical/biological study (experimental study)

Frequency-specific effects of millimeter-wavelength electromagnetic radiation in isolated nerve. med./bio.

Published in: Electro Magnetobiol 1997; 16 (1): 43-57

Aim of study (acc. to author)

Previous work revealed that millimeter waves (MMW) attenuated the compound action potential (CAP) suppression caused by high-rate electrical stimulation (HRS), but only at certain frequencies of the radiation. The objective of this study was to analyze the frequency dependence of this effect in more detail, as well as to confirm it in an independent series of experiments.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 41.14–41.54 Hz
Modulation type: CW
Exposure duration: 38 min
Exposure 2: 50.8–51 Hz
Modulation type: CW
Exposure duration: 38 min
Exposure 3: 45.9–45.93 Hz
Modulation type: CW
Exposure duration: 38 min

Exposure 1

Main characteristics
Frequency 41.14–41.54 Hz
Type
Exposure duration 38 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.052 m
Sham exposure A sham exposure was conducted.
Additional info For nerve stimulation saline bridge electrodes were positioned on opposite sites of the nerve; the nerve was stimulated with square pulses with a pulse width of 0.2 ms and an amplitude of U = 2 - 5 V; the interval between two pulses in a pair was 9 ms
Parameters
Measurand Value Type Method Mass Remarks
power density 0.27 mW/cm² maximum measured and calculated - -
power density 0.25 mW/cm² minimum measured and calculated - -

Exposure 2

Main characteristics
Frequency 50.8–51 Hz
Type
Exposure duration 38 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.052 m
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 0.27 mW/cm² maximum measured and calculated - -
power density 0.25 mW/cm² minimum measured and calculated - -

Exposure 3

Main characteristics
Frequency 45.9–45.93 Hz
Type
Exposure duration 38 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.052 m
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 2.5 mW/cm² minimum measured and calculated - -
power density 2.7 mW/cm² maximum measured and calculated - -

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

Millimeter-wave (MMW) exposure at certain frequencies increased the test-CAP (compound action potential) relative amplitude, or, in other words, irradiation attenuated the HRS (high-rate electrical stimulation)-induced diminution of the test CAP. This effect can be interpreted as an improvement of the nerve refractory properties under the action of MMW.
The results provide evidence for the existence of frequency-specific, resonance-type mechanisms of MMW interaction with biological systems.

Study character:

Study funded by

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