Study type: Medical/biological study (experimental study)

A pilot investigation of the effect of extremely low frequency pulsed electromagnetic fields on humans' heart rate variability. med./bio.

Published in: Bioelectromagnetics 2007; 28 (1): 64-68

Aim of study (acc. to author)

(1) To test the response to exposure to an extremely low frequency pulsed electromagnetic field with constant pulsing frequency on cardiovascular function of a small number of healthy subjects (five males age 30-65 years).
(2) to test responses to an extremely low frequency pulsed electromagnetic field pulsed at various frequencies in one subject exposed on 5 consecutive days, a different pulsing frequency each day.

Background/further details

In this study power spectral density is the investigative tool used. The power spectral density of the signal obtained from the RR intervals shows the contribution of rhythmic fluctuations that may affect the heart frequency. The autonomic nervous system controls the heart rate variability with sympathetic and parasympathetic afferents. This control can be detected in the lower frequency range, 0.04-0.15 Hz, for the sympathetic branch of autonomic nervous system and in the higher frequency band, 0.15-0.4 Hz, for the parasympathetic or vagal branch of the autonomic nervous system. Consequently, the lower frequency/higher frequency ratio is considered to mirror sympatho-vagal balance.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Modulation type: pulsed
Exposure duration: 5 to 10 min off - 20 min on - 20 min off - 20 min on - 5 to 15 min off
Exposure 2: 50 Hz
Modulation type: pulsed
Exposure duration: exposure of one person to different extremly low frequency pulsed electromagnetic fields on 5 consecutive days

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration 5 to 10 min off - 20 min on - 20 min off - 20 min on - 5 to 15 min off
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Distance between exposed object and exposure source 90 cm
Chamber the pad radiating the pulsed field was placed on the floor under the seat of the test persons
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 4.21 µT - measured - value at the heart of the test persons

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration exposure of one person to different extremly low frequency pulsed electromagnetic fields on 5 consecutive days
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 4.21 µT - measured - at the haert of the testperson

Reference articles

  • Baldi E et al. (1999): A pilot study on the extremely low frequency (ELF) pulsing magnetic field (PMF) effect on soft tissue injuries: A preliminary analysis of the results.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The data revealed a heart rate variation in all the subjects when they are exposed to the same extremely low frequency pulsed electromagnetic field. This variation could be detected by observing the change in the sympatho-vagal equilibrium. Variation of the "lower frequency/higher frequency power spectral density" ratio mainly occured at transition times from exposure to non-exposure, or vice versa.
In the case of the same subject exposed to different pulse frequencies, the responses to the stimuli with a pulse frequency of 3 Hz and 4 Hz showed a noticeable variation in power spectral density ratio during the second period of exposure when compared to other pulsed electromagnetic fields.

Study character:

Study funded by

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