Study type: Medical/biological study (experimental study)

Microwave pulse-induced acoustic resonances in spherical head models. tech./dosim.

Published in: IEEE Trans Microw Theory Tech 1981; 29 (10): 1114-1117

Aim of study (acc. to author)

To measure microwave-induced acoustic pressure waves in spherical models of human and animal heads (filled with brain-equivalent material) using a small hydrophone transducer.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.1 GHz
Modulation type: single pulse, pulsed
Exposure duration: 1 or 3 pulses
Exposure 2: 1.1 GHz
Modulation type: single pulse, pulsed
Exposure duration: 1 or 3 pulses
Exposure 3: 1.1 GHz
Modulation type: single pulse, pulsed
Exposure duration: 1 or 3 pulses

Exposure 1

Main characteristics
Frequency 1.1 GHz
Type
Exposure duration 1 or 3 pulses
Modulation
Modulation type single pulse, pulsed
Pulse width 35 µs
Additional info

trains of 3 pulses with a repetition rate of 5-20 kHz

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 4 kW peak value - - -

Exposure 2

Main characteristics
Frequency 1.1 GHz
Type
Exposure duration 1 or 3 pulses
Modulation
Modulation type single pulse, pulsed
Pulse width 14 µs
Additional info

trains of 3 pulses with a repetition rate of 10-30 kHz

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 4 kW peak value - - -

Exposure 3

Main characteristics
Frequency 1.1 GHz
Type
Exposure duration 1 or 3 pulses
Modulation
Modulation type single pulse, pulsed
Pulse width 10 µs
Additional info

trains of 3 pulses with a repetition rate of 20-40 kHz

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 4 kW peak value - - -

Reference articles

  • Guy AW (2013): Electromagnetic Fields and Relative Heating Patterns Due to a Rectangular Aperture Source in Direct Contact with Bilayered Biological Tissue.
  • Olsen RG et al. (1980): Microwave-induced pressure waves in a model of muscle tissue.

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The data demonstrate that microwave pulses can generate measurable acoustic pressures in spherical models of human and animal heads. In addition, they show that appropriately selected pulse repetition frequencies stimulate acoustic resonances that can elevate the microwave-induced acoustic pressure by severalfold. The agreement between calculated and measured frequencies of acoustic pressure waves lend further support to the thermoelastic mechanism of interaction.

Study character:

Study funded by

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