Simulating Focused Ultrasound Transducers Using Discrete Sources on Regular Cartesian Grids.
Summary
A new discrete source model accurately represents complex ultrasound transducer shapes in simulations. This method models bowl-shaped arrays, improving ultrasound therapy simulations even with nonplanar surfaces.
Area of Science:
- Acoustics
- Biomedical Engineering
- Computational Physics
Background:
- Accurate ultrasound simulation is crucial for therapy, especially with multielement arrays.
- Current methods struggle with nonplanar transducer geometries.
- Modeling complex source geometries is a significant challenge in ultrasound simulation.
Purpose of the Study:
- To develop a grid-based discrete source model for single- and multielement bowl-shaped transducers.
- To explicitly model source geometry within a regular Cartesian grid.
- To enable accurate ultrasound simulations for nonplanar transducer arrays.
Main Methods:
- Developed a discrete source model defining each element as a symmetric, single grid point thick surface.
- Integrated the model into the open-source k-Wave toolbox.
- Validated simulations against Rayleigh integral, O'Neil solution, and experimental measurements.
Main Results:
- The discrete bowl model showed close agreement with the O'Neil solution for axial pressure, even at low grid resolutions.
- Excellent agreement was observed between the model and experimental measurements.
- Uniformly radiating monopole sources on the bowl surface provided good focal region agreement.
Conclusions:
- The discrete source model accurately represents bowl-shaped transducer geometry in ultrasound simulations.
- This approach facilitates modeling of multielement transducers with nonplanar surfaces.
- The model offers a viable solution for complex source geometries where plane wave assumptions fail.
