Synergistic effects of material parameters and pressure wave characteristics on pulsed high-powered microwave induced cavitation injury

Prior work has shown that pulsed high-powered microwave exposure can lead to rapid thermoelastic expansion of brain tissue which is subject to a strain-focusing effect. The rapid increase in thermal strain causes pressure waves to form in the brain and reverberate as tensile waves. This study investigates possibly synergies between brain material properties, like viscosity, shear modulus, and cavitation nuclei size, and pressure waveform properties like amplitude and frequency. Cavitation is modeled using the Keller–Miksis equation modified to incorporate viscoelastic effects. A fourth-order variable time step Runge–Kutta scheme calculates bubble radii and wall velocities from the pressure profile. By performing a 6-D parameter sweep, regions of the parameter space where cavitation is more likely to occur are found. This will identify exposure limits to minimize microwave induced brain injury.