Simulation of 3D Ultrasound Wave Propagation through Abdomen-mimicking Media using k-Wave MATLAB Toolbox: toward the application of ultrasound-guided for needle insertion

摘要

The propagation of ultrasound wave through abdominal-mimicking heterogeneous medium is described with a model using k-Wave toolbox on MATLAB. This model is built based on a series of coupled first-order partial differential equations describing the dynamic changes of physical parameters, i.e. pressure, density and particle velocity. The discretization of the governing equations is performed using pseudospectral scheme. The Fourier collocation spectral method is used to compute spatial derivatives, while time integration is performed using leapfrog finite difference. To simulate the propagation of ultrasound waves in free space without condition of wave "wrapping round", a perfectly matched layer (PML) is also applied to absorb the waves at the edge of computational domain. A time-domain propagation of compressional waves through a 3D heterogeneous acoustic medium is simulated using function kspaceFirstOrder3D, given four input structures defined custom input parameters. These input structures represent the medium properties and the specification of ultrasound transducer (as source and sensor). In this case, the defined media consist of media 1 (5 layers abdomen-mimicking media) and media 2 (5 layers abdomen-mimicking media, added with a highly reflective ball object in the bottom layer), while the transducer is 128 elements linear array. Propagation of wave field is computed step by step, with the field values recorded after each iteration.