Biomedical Fluid Dynamics


Topics of Interest


Ultrasound Contrast Agents (UCA) are micron-sized bubbles commonly used in medical ultrasound applications to enhance the detection of blood flow in ecographic images. However the potential applications of these bubbles extend beyond their use as contrast agents. They have proven their usefulness as flow tracers, giving birth to the technique commonly known as EchoPIV, that allows  researchers to quantitatively characterize blood flow fields in vivo. These bubbles can also be used as drug carriers since, once inside the circulatory system, they can be accurately targeted to specific locations using ultrasound, through an effect known as the Bjerknes force. In our research group we conduct experimental, numerical and theoretical studies on the ultrasound-microbubble interaction, with two aims:
- the use of microbubbles as flow tracers in the EchoPIV technique,
- effective use of the Bjerknes force to target microbubbles to specific locations.

  • T. Hölscher, J. Rodríguez-Rodríguez, W. Wilkening, J.C. Lasheras, U. H. Sang. Intra-Operative brain ultrasound: a new approach to study flow dynamics in intracraneal aneurysms. Ultrasound in Medicine and Biology, 32, 1307-1313 (2006)

Ongoing Research Projects

Development of a non-invasive pressure measurement technique based on the analysis of the acoustic spectrum of microbubbles
Funding Agency: Spanish MICINN
Duration: 2009-2011
Contract # DPI2008-06369

The goal of the project is to develop a non-invasive technique to experimentally determine the pressure at a given point in a liquid by measuring the resonance frequency of a cloud of bubbles with sizes in the micrometer range.

The intended application of this method is the noninvasive measurement of the pressure inside the heart or any other point of the vascular system in medical patients.

As the highest impact of the technique would be in medical applications, part of the project is devoted to adress the particularities of ultrasound medical diagnostics. More specifically, part of the results are intended to help in the design of ultrasound contrast agents commonly used in medicine.