Measuring Blood Pressure using Microbubbles and Ultrasound

Gas microbubbles have a high compressibility, which make them very efficient sound scatterers. As another consequence of their high compressibility, microbubbles can be compressed by the pressure of the fluid around them, which affects their scattering properties. Due to recent progress in shelled ultrasound contrast agents and the development of almost monodispersed microbubbles, we believe it could now be possible to measure blood pressure using microbubbles as non-invasive manometers, an idea first suggested more than 30 years ago. In this thesis, both simulations and in vitro experiments will be used to investigate the changes related to the resonance of bubbles and how the concept of bubble size population affects the accuracy of this technique. In particular, it will be shown how shell dynamics dominates the response of microbubbles to blood pressure.MAS