The role of the diagnostic ultrasound intensity on pulmonary alveolus deformation

Focused diagnostic ultrasound, used for medical visualization of soft biological tissue, has been observed to generate harmful bioeffects such as hemorrhaging of the lung tissue. Prior 2D gas-liquid numerical simulations [Patterson and Johnsen, PRF (2018)] using a trapezoidal incident wave showed that hemorrhage may be induced due to vorticity-generated large perturbation growth at the interface. The hypothesis of this work is that the interface morphology-vorticity interaction can be dynamically modulated to safely use ultrasound waveforms and amplitudes outside recommended ranges and increase contrast. We perform 3D numerical simulations of the deformation of the lung tissue-alveolar interface due to the diagnostic ultrasound waveform and a model of the lung interface. We use the open-source Multicomponent Flow Code (MFC) [Radhakrishnan & Le Berre et al. Comp. Phys. Comm. (2024)] to examine the interface morphology for different wave frequencies and pressure amplitudes and their relationship with elasticity. Using a Fourier analysis, we present simulations using waveforms with different frequencies and pressure amplitudes that may inhibit interfacial instabilities that lead to rupture.