Abnormal cardiovascular responses induced by localized high power microwave exposure

Area of Science:

• Biophysics
• Physiology
• Electromagnetics

Background:

• Microwave exposure is a growing concern for biological systems.
• Understanding the physiological effects of microwaves is crucial for safety guidelines.
• Previous research suggests potential impacts on circulatory function.

Purpose of the Study:

• To test the hypothesis of microwave-induced circulatory underperfusion.
• To investigate the effects of different microwave exposure parameters on physiological functions.
• To determine if microwave exposure alters cardiac output and peripheral resistance.

Main Methods:

• Utilized ketamine anesthetized rats for controlled experiments.
• Monitored heart rate, mean arterial pressure, pulse pressure, respiration rate, and body temperature.
• Exposed rats to sham, continuous wave (CW), and pulsed 1.25 GHz microwaves at varying power levels and frequencies.

Main Results:

• Respiration rate and mean arterial pressure remained unaltered.
• Higher power microwave exposure (16 Hz pulses, 6.4 W CW) altered heart rate and pulse pressure.
• Observed whole-body hyperthermia correlated with changes in heart rate and pulse pressure.
• Cardiac output was inferred to be below normal in higher power exposure groups.
• Increased total peripheral resistance was noted, contradicting anticipated thermal responses.

Conclusions:

• Microwave exposure, particularly at higher power levels, can induce circulatory underperfusion in rats.
• Observed physiological changes suggest a complex interaction between microwave energy and cardiovascular regulation.
• The findings indicate that microwave exposure can lead to non-thermal effects on circulation, impacting total peripheral resistance.