Study type: Medical/biological study (experimental study)

High-peak-power microwave pulses: effects on heart rate and blood pressure in unanesthetized rats. med./bio.

Published in: Aviat Space Environ Med 1995; 66 (10): 992-997

Aim of study (acc. to author)

To study the presence and absence of heart rate and blood pressure changes during two separate series of exposure of rats to high-peak-power microwave pulses: 1) initial pilot studies of 1.7-1.8 GHz exposures; and 2) further studies of 1.2-1.4 GHz at higher peak power densities.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.7–1.8 GHz
Modulation type: pulsed
Exposure duration: continuous for 10 s
Exposure 2: 1.2–1.4 GHz
Modulation type: pulsed
Exposure duration: continuous for 10 s

General information

Pulse durations and peak power densities were not constant during any exposure period. Details of the propagated field, typical waveforms, and dosimetry have been published previously [Platt et al., 1989].

Exposure 1

Main characteristics
Frequency 1.7–1.8 GHz
Type
Exposure duration continuous for 10 s
Modulation
Modulation type pulsed
Repetition frequency 1 Hz
Additional info

pulse width of 40-85 ns

Exposure setup
Exposure source
Distance between exposed object and exposure source 3 m
Setup Animals were individually placed in a vented restraint cage, which allowed some movement but maintained the long axis of the body in a fixed position relative to the field. The cage was positioned 10° left of the antenna boresight at a distance of 3 m.
Sham exposure A sham exposure was conducted.
Additional info The animal was exposed to 10 MW pulses. During the exposure, a sharp sound was emitted with each pulse. For this reason, the same animal was exposed after 10-15 min to another 10 pulses, using a 2-in thick Styrofoam shield to cover the horn antenna and achieve sound attenuation. In addition, a sham exposure was performed using the Styrofoam shield and an aluminium-foil shield to eliminate MW transmission. The sequence of shielded and non-shielded exposures to each animal was randomized.
Parameters
Measurand Value Type Method Mass Remarks
power density 4.5 kW/cm² peak value measured - 3.3-6.5 kW/cm²

Exposure 2

Main characteristics
Frequency 1.2–1.4 GHz
Type
Exposure duration continuous for 10 s
Modulation
Modulation type pulsed
Repetition frequency 1 Hz
Additional info

pulse width of 40-70 ns

Exposure setup
Exposure source
Distance between exposed object and exposure source 3 m
Sham exposure A sham exposure was conducted.
Additional info The sound was attenuated by adding Eccosorb sound-absorbing material around the perimeter of the antenna. Effects of shielding with aluminium foil alone were tested.
Parameters
Measurand Value Type Method Mass Remarks
power density 32.6 kW/cm² peak value measured - 14.6-51.6 kW/cm²

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The results do not suggest any serious detrimental cardiovascular effects resulting from acute exposure of rats to high-peak-power microwave pulses.

Study character:

Study funded by