Members

• Nicolò Speciale
  
• Nicola Testoni

Project description

Discovered while studying ultrasound (US) contrast agents, the excitation of higher frequencies due to tissues non-linearities (NL) is commonly occurring even at the signal powers involved in clinical applications. The traveling US beam causes local compression and rarefaction in the material which is traversing in. These slight alterations in density imping the US beam propagation speed, causing the compression part of the pulse to travel relatively faster with respect to the rarefaction part. The distortion of the signal waveform grows over traveling distance and generates the additional harmonics.

We address the problem of nonlinear propagation of sound radiating from a finite aperture cylindrical source. We exploit the intrinsic symmetry of the problem by adopting a set of cylindrical coordinates centered on the source axis. Within this framework, we efficiently estimate the fundamental and the harmonic terms of the pressure field described by the solution of the KZK equation by systematically applying Hankel and Fourier Transforms.

We are therefore capable of simulating NL US fields with significant computational savings and an accuracy at least comparable to other standard approaches to the same problem. Comparing our algorithm to the output of publicly available NL KZK solver, we recorded significant cost reductions and performance improvements.

Contact: Nicola Testoni > This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

Collaborations

• Ruhr-Univeristy of Bochum, Germany - Lehrstuhl fur Medizintechnik

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References

• See publications.