Effect of low pulsed microwaves on heart rate variability signals in mammals

OBJECTIVE: The main objective of this work is to study the effect of low pulsed microwaves on the heart rate variability signals derived from electrocardiogram signals of ten cats irradiated with pulsed microwaves with 5.655GHz.

METHODS: Electrocardiograms of ten anaesthetized cats were measured and recorded using implanted electrodes before microwave exposure. Rectangular pulses at 5.655GHz, 2 w peak, 5.5us wide and repetition rate 2 Hz were applied to the brain of cats through horns and wave guides for 20 minutes, followed by a 20 minute recovery period after exposure.

RESULTS: The results clearly indicate that the pulsed microwaves radiation induced high fluctuations in power spectra of heart rate variability signals specially in the band of 8s to 80s.(0.0125 Hz to 0.125Hz) which is related to the thermoregulatory control activity. Examining the power spectra of heart rate variability of recovery period(after 20 minutes microwave exposure) shows that the change of power spectra of heart rate variability signal during microwave exposure is not permanent.

CONCLUSION: The analysis of power spectra of heart rate variability signals of ten anaesthetized cats before, during and after exposure to low power microwave radiation seems useful to indicate the interaction of pulsed microwaves with cardiovascular system, autonomic function and body control mechanism.