Add displacement and cavitation simulations

[charlesbmi]

Describe the new feature or enhancement

• FUS can displace the peripheral nerves and thereby modulate pain. Can also detect this displacement via ultrasound.
• Quantitative Frequency-Domain Passive Cavitation Imaging

Thus, it might be interesting to be able to model displacement and cavitation for different pulse sequences.

Describe your proposed implementation

Would need to understand if these mechanisms can fit into the stride (or other wave-propagation model)