Study type: Medical/biological study (experimental study)

Rhesus monkey behavior during exposure to high-peak-power 5.62-GHz microwave pulses med./bio.

By: D'Andrea JA, Thomas A, Hatcher DJ
Published in: Bioelectromagnetics 1994; 15 (2): 163-176
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Aim of study (acc. to author)

To study the behavioral effects of very high-peak-power 5.62 GHz microwaves on Rhesus monkey trained on an operant task for food pellet reward.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 5.62 GHz
Modulation type: pulsed
Exposure duration: continuous for 20 min
Exposure 2: 5.62 GHz
Modulation type: pulsed
Exposure duration: continuous for 20 min

Exposure 1

Main characteristics
Frequency 5.62 GHz
Type
Exposure duration continuous for 20 min
Modulation
Modulation type pulsed
Pulse width 2.8 µs
Repetition frequency 100 Hz
Exposure setup
Exposure source
Distance between exposed object and exposure source 1 m
Setup The monkeys were seated in a PVC pipe chair. The monkey's head was at or near the center of the MW beam with the long axis of the body aligned parallel to the electric field vector.
Sham exposure A sham exposure was conducted.
Additional info Exposure sessions at three different SARs and a sham session were given in random order on different days. A white-noise source produced a 75 dBA masking sound.
Parameters
Measurand Value Type Method Mass Remarks
power density 56 W/cm² peak value measured - -
power density 28 mW/cm² mean measured - -
SAR 2 W/kg average over mass measured whole body -
power density 128 W/cm² peak value measured - -
power density 56 mW/cm² mean measured - -
SAR 4 W/kg average over mass measured whole body -
power density 277 W/cm² peak value measured - -
power density 83 mW/cm² mean measured - -
SAR 6 W/kg average over mass measured whole body -
Measurement and calculation details

A calibrated waveguide directional coupler was mounted prior to the horn antenna to monitor the peak and mean powers. Whole-body SAR was measured using a pair of monkey bag models filled with simulated muscle tissue and twin-well calorimetry. Localized SAR was measured by inserting three small plastic cannulae and MW-compatible temperature probes in the head and the neck of the model. In addition, a saline filled 3-liter plastic bottle, approx. the size of the monkey, was used to measure SAR in the monkey chair prior to exposure.

Exposure 2

Main characteristics
Frequency 5.62 GHz
Type
Exposure duration continuous for 20 min
Additional info Farkas ZD, Hogg HA, Loew GA, Wilson PB: SLED: A Method of Doubling SLAC's Energy. Publication No. 1453 (1974). Recent Progress on SLED, The SLAC Energy Doubler. Publication No. 1561 (1975). Stanford Linear Accelerator Center. Stanford, CA: Stanford University.
Modulation
Modulation type pulsed
Pulse width 50 ns
Repetition frequency 100 Hz
Additional info

The SLED added a high-peak-power pulse of 50 ns duration to the normal radar pulse.
Exposure setup
Exposure source
Distance between exposed object and exposure source 1 m
Setup A description of the setup and operation of Stanford linear energy doubler (SLED) pulse-forming devices has been presented elsewhere [Farkas et al., 1974, 1975]. SLED pulses were only created when the resonant cavities on the SLED were tuned to 5.62 GHz; otherwise, the radar pulses passed through unamplified.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 518 W/cm² peak value measured - -
power density 28 mW/cm² mean measured - -
SAR 2 W/kg average over mass measured whole body -
power density 1,270 W/cm² peak value measured - -
power density 56 mW/cm² mean measured - -
SAR 4 W/kg average over mass measured whole body -
power density 2,520 W/cm² peak value measured - -
power density 83 mW/cm² mean measured - -
SAR 6 W/kg average over mass measured whole body -
Additional parameter details

The SLED device enhanced the peak power by a factor of nine.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Compared to sham exposure, significant alterations of responding (responses during microwave exposure declined significantly), reaction time (reaction time decreased), and earned food pellets (microwave exposure significantly reduced the number of food pellets) occured during microwave irradiation at 4 and 6 W/kg but not at 2 W/kg. There were no differences between military radar or SLED (Stanford linear energy doubler) pulses in producing behavioral effects.

Study character:

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