OptimUS

An open-source Python library for solving 3D acoustic wave propagation.

The OptimUS library provides functionality to simulate acoustic wave propagation in an unbounded domain with multiple scatterers. OptimUS solves the Helmholtz equation in multiple domains with homogeneous material parameters, using a boundary element method (BEM). The library targets general acoustical simulation and has functionality for focused ultrasound in biomedical engineering.

Installation

The OptimUS library and all dependencies are installed and tested in a Docker container. First, install the docker engine on your machine following the instruction on the docker website. Then, pull the docker container by running:

bash docker pull optimuslib/optimus:latest

Downloading and installing the OptimUS' Docker image takes several minutes and requires a stable internet connection. This step can be skipped next time you use the Docker image and is only necessary to update with a new release.

To start the container on your machine, run:

bash docker run -it -v $(pwd):/home/optimus/localwork --workdir /home/optimus/localwork -p 8888:8888 optimuslib/optimus:latest The output will provide the URL and token to access the Jupyter notebook interface from a web browser.

Upon accessing Jupyter, you can execute the notebooks available in the notebook directory on this GitHub page.

If you want to get a bash terminal within the container, you can either launch one through the Jupyter notebook interface or via Docker as:

bash docker run -it --rm -v $(pwd):/home/optimus/localwork --workdir /home/optimus/localwork optimuslib/optimus:latest

In the terminal, you can execute your Python files by running:

bash python3 <file_name.py>

Troubleshooting

Depending on the configuration of your machine's OS, you may need to adapt the above Docker commands. - Some systems require running the above Docker commands as a super user. In a bash terminal use: sudo docker instead of docker. - On Windows, PowerShell works best. Other shell environments may not detect $(pwd) as the current working directory and one needs to provide the full path, for example, C:\Users\myname:/home/optimus/localwork with the first part adapted to the path of your local folder to be detected in the Docker container.

Documentation

Examples are available in the notebook directory on this GitHub page. Automatically generated documentation of the Python API can be found in Read the Docs optimus project.

Getting help

Enquiries about the library and questions should be asked on the GitHub discussion page. Errors in the library should be added to the GitHub issue tracker.

Citation

If you use OptimUS in your work, please cite it as follows:

APA Gélat, P., Haqshenas, S. R., and van 't Wout, E. (2022), OptimUS: A Python library for solving 3D acoustic wave propagation, https://github.com/optimuslib/optimus

BibTeX @software{optimuslib, author = {Gélat, Pierre and Haqshenas, Reza and van 't Wout, Elwin}, title = {OptimUS}, url = {https://github.com/optimuslib/optimus}, version = {0.2.1} }

https://doi.org/10.5281/zenodo.15039756

Acknowledgement

• The OptimUS library uses the bempp-legacy library from the BEMPP project as the computational backend.
• The tissue properties database is based on Tissue Properties Database V4.1 of IT'IS Foundation.

Licence

OptimUS is licensed under an MIT licence. Full text of the licence can be found here.

References

The main references describing the BEM formulations and preconditioners implemented in OptimUS are as follows:

Haqshenas, S. R., Gélat, P., van 't Wout, E., Betcke, T., & Saffari, N. (2021). A fast full-wave solver for calculating ultrasound propagation in the body. Ultrasonics, 110, 106240. doi:10.1016/j.ultras.2020.106240

van 't Wout, E., Haqshenas, S. R., Gélat, P., Betcke, T., & Saffari, N. (2021). Benchmarking preconditioned boundary integral formulations for acoustics. International Journal for Numerical Methods in Engineering, nme.6777. doi:10.1002/nme.6777

van 't Wout, E., Haqshenas, S. R., Gélat, P., Betcke, T., & Saffari, N. (2022). Boundary integral formulations for acoustic modelling of high-contrast media. Computers & Mathematics with Applications, 105, 136-149. doi:10.1016/j.camwa.2021.11.021

van 't Wout, E., Haqshenas, S. R., Gélat, P., Betcke, T., & Saffari, N. (2022). Frequency-robust preconditioning of boundary integral equations for acoustic transmission. Journal of Computational Physics, 111229. doi:10.1016/j.jcp.2022.111229