Simulation of Acoustical Field of Ballistic Shock Therapy Device by the Lattice Boltzmann Method

The pressure field distribution of a ballistic shock wave (BSW) therapy device is a crucial factor for clarifying its treatment mechanism. We developed a lattice Boltzmann model (LBM) to describe the propagation of BSW. Based on the assumption that the propagation of BSW causes weak compressible flow, our simulaton was performed by coupling Tait equation of state. For a two-dimensional LBM, we used the density initial condition for initial turbulent region near the applicator. We first compared our simulation results with previous experimental measurements. Then we predicted the temporal and spatial distribution of pressure field. The pressure field of ballistic shock wave has a primary compressive region followed by a primary expansive region with the other disturbances. A secondary pressure pulse consists of a positive phase followed by a negative phase. Our results agree well with previous experimental data and provide additional data on the pressure field of BSW. Our model encourages further investigation to clear the biological mechanism of BSW therapy and to design more effective device.