Jet formation of contrast microbubbles in the vicinity of a vessel wall

Abstract

Behaviors of microbubble contrast agent near a vessel wall under ultrasound excitation are investigated using a boundary integral method. Ultrasound in the presence of microbubbles facilitates drug delivery by streaming and jetting phenomena. The microbubbles are encapsulated by a layer of proteins or lipids to stabilize them against dissolution. The encapsulating shell of the contrast microbubble is viscoelastic modeled here by three different interfacial rheological models. While at low excitations microbubbles undergo regular oscillations, at high amplitudes excitation, they form jets toward the wall. The dynamics and the resulting shear stress on the wall are studied varying the shell rheology and other relevant parameters of the problem.