Droplets, bubbles and ultrasound interactions

O Shpak, MD Verweij, N de Jong, M Versluis

Research output: Chapter in Book/Conference proceedings/Edited volumeChapterScientific

30 Citations (Scopus)

Abstract

The interaction of droplets and bubbles with ultrasound has been studied extensively in the last 25 years. Microbubbles are broadly used in diagnostic and therapeutic medical applications, for instance, as ultrasound contrast agents. They have a similar size as red blood cells, and thus are able to circulate within blood vessels. Perfluorocarbon liquid droplets can be a potential new generation of microbubble agents as ultrasound can trigger their conversion into gas bubbles. Prior to activation, they are at least five times smaller in diameter than the resulting bubbles. Together with the violent nature of the phase-transition, the droplets can be used for local drug delivery, embolotherapy, HIFU enhancement and tumor imaging. Here we explain the basics of bubble dynamics, described by the Rayleigh-Plesset equation, bubble resonance frequency, damping and quality factor. We show the elegant calculation of the above characteristics for the case of small amplitude oscillations by linearizing the equations. The effect and importance of a bubble coating and effective surface tension are also discussed. We give the main characteristics of the power spectrum of bubble oscillations. Preceding bubble dynamics, ultrasound propagation is introduced. We explain the speed of sound, nonlinearity and attenuation terms. We examine bubble ultrasound scattering and how it depends on the wave-shape of the incident wave. Finally, we introduce droplet interaction with ultrasound. We elucidate the ultrasound-focusing concept within a droplets sphere, droplet shaking due to media compressibility and droplet phase-conversion dynamics.
Original languageEnglish
Title of host publicationTherapeutic ultrasound
EditorsJM Escoffre, A Bouakaz
Place of PublicationBasel, Switzerland
PublisherSpringer
Pages157-174
ISBN (Print)978-3-319-22535-7
DOIs
Publication statusPublished - 2016

Publication series

Name Advances in Experimental Medicine and Biology
Volume880

Bibliographical note

Harvest

Keywords

  • Droplet
  • Microbubble
  • Ultrasound

Fingerprint

Dive into the research topics of 'Droplets, bubbles and ultrasound interactions'. Together they form a unique fingerprint.

Cite this