Modeling Electromagnetically Driven Thermoacoustic Pressure Wave Buildup in the Brain.

The proliferation of wireless communications, high-power microwave (HPM) sources, radar, and other microwave technology has necessitated research into potential HPM bioeffects. Here we present a multi-physics simulation study to probe the possible generation of thermoacoustic pressure waves from incident electromagnetic pulses, in a layered dielectric representation of the human head. The model is designed to offer flexibility with customizable pulse length, rise and fall times, repetition rates, applied electric field value, and user-defined directional orientation. Our results suggest that pressure could be generated at the center of the intra-cranial region, qualitatively in keeping with some reports in the literature. Continuous pulsing is seen to lead to pressure build-up in the head close to the location of incident stimulus; while with short-pulsed stimulation, the effects are predicted to be greater at the center of the intra-cranial region. The results also show that with decreases in pulse length, while the absolute pressure amplitude is enhanced, the disturbance becomes less oscillatory in nature.