InterPore2023

A volume-averaged model for acoustic streaming induced by focused ultrasound in soft porous media

24 May 2023, 12:30

15m

Oral Presentation (MS20) Biophysics of living porous media: theory, experiment, modeling and characterization MS20

Speaker

Mr Sebastian Price (PoreLab and Department of Chemistry, The Norwegian University of Science and Technology (NTNU))

Description

Ultrasound has been found to improve the delivery of therapeutic agents into
tumors thereby improving the therapeutic response in cancer treatment [1].
Acoustic streaming which is the net movement of fluid generated by propagation
of sound waves is one of the many proposed mechanisms for this improvement.
However, it would be of great advantage to have an experimentally validated
model in order to understand acoustic streaming, and to compare its effect rel-
ative to other possible mechanisms for improved delivery.

We have derived equations describing acoustic streaming in soft porous me-
dia driven by focused ultrasound. From these equations we created a model
that predicts the time-averaged flow on the macroscopic scale as well as the
advective transport of the trace components in the fluid. We used this model
to perform simulations for different shapes of the focused ultrasound beam.
The results from the simulations was also compared to a simplified expression
which states that the dimensionless volumetric flux is equal to the dimensionless
acoustic radiation force. Finally, we performed a comparison between the model
for acoustic streaming to experimental results and we found good agreement,
where the predicted volumetric fluxes, averaged over the beam full-width half-
maximum, was well within the experimental uncertainties. The hope is that the
model can be used to interpret experimental results relevant for enhanced drug
delivery in tissue, and to assess the relative importance of acoustic streaming
compared with other effects.

References

[1] S. Snipstad, K. Vikedal, M. Maardalen, A. Kurbatskaya,
E. Sulheim, and C. de Lange Davies, Ultrasound and mi-
crobubbles to beat barriers in tumors: Improving deliv-
ery of nanomedicine, Advanced Drug Delivery Reviews
177, 113847 (2021).