A setup for the assessment of the effect of tubular confinement on the acoustic response of microbubbles

Mairead B. Butler, Aris Dermitzakis, Padraig Looney, David H. Thomas, Stephen D. Pye, Vassilis Sboros

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Ultrasound contrast agents are gas filled microbubbles which produced enhanced echoes in ultrasound imaging thus allowing the acquisition of detailed information on the path of blood. It is theoretically known that the size of a vessel affects the behavior of a microbubble, which could potentially be used to discriminate different sized vessels. This information would be useful in the monitoring of neovascularization in tumor growth or treatment. However, currently it is not possible to identify the vessel diameter by any means of signal processing of microbubble echoes. In order to assess microbubble behavior when confined in tubes we compared the acoustic backscatter from biSphere (TM) microbubbles both free in water and flowing in 200 mu m diameter tubes that are similar in size to arterioles. Experimental systems that allow the interrogation of individual microbubbles were designed and modified to allow investigation of both free microbubbles and those in tubes. Unprocessed single microbubble RF data were collected, allowing the calculation of both the fundamental and second harmonic components of the backscattered signal. Microbubbles confined in tubes had lower amplitude response compared to unconfined microbubbles. On consecutive insonations of the same microbubble, free microbubbles produced echoes above noise more often than confined microbubbles. This setup may be used to investigate microbubble behavior in a range of smaller tubes with diameters similar to capillaries thus enabling signal processing design for vessel differentiation.

Original languageEnglish
Title of host publication2014 36TH Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)
Place of PublicationNew York
Number of pages4
Publication statusPublished - 2014
Event36th Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society - Chicago, Israel
Duration: 26 Aug 201430 Aug 2014

Publication series

NameIEEE Engineering in Medicine and Biology Society Conference Proceedings
ISSN (Print)1557-170X


Conference36th Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society
Abbreviated titleEMBC



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