title: Effect of an elastic wall on the dynamics of an encapsulated microbubble: A simulation study.
abstract: The purpose of the present simulation study is to reveal how confining surfaces with different mechanical properties affect the acoustic response of a contrast agent microbubble. To this end, numerical simulations are carried out for three types of walls: a plastic (OptiCell) wall, an aluminium wall, and a biological tissue. For each wall, the behaviour of contrast microbubbles of three sizes is investigated. The spectral characteristics of the scattered pressure produced by the microbubbles are compared for two cases: the bubble oscillates far away from the wall and the same bubble oscillates in the immediate vicinity of the wall. The results of the simulations allow one to make the following main conclusions. The effect of the OptiCell wall on the acoustic bubble response is stronger than that of the aluminium and tissue walls. Changes in the bubble response near the wall are stronger when bubbles are excited above their resonance frequency. Considering changes in the fundamental and the 2nd harmonic with respect to the peak values of these components at different bubble radii, it is found that the changes are stronger for smaller bubbles and that the changes in the 2nd harmonic are stronger than those in the fundamental. These results allow one to gain an insight into conditions under which the effect of an elastic wall on the acoustic response of a contrast agent microbubble is easier to be detected.
authors.affiliation: INSERM U930, CNRS ERL3106, Université François Rabelais, CHU Bretonneau, 2 Boulevard Tonnellé, 37044 Tours Cedex 9, France.
authors.forename: Leila
authors.initials: L
authors.lastname: Aired
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Doinikov
authors.forename: Ayache
authors.initials: A
authors.lastname: Bouakaz
mesh_terms: D000465:Algorithms; D000535:Aluminum; D003198:Computer Simulation; D003287:Contrast Media / Q000737:chemistry*; D004548:Elasticity; D045423:Microbubbles; D010969:Plastics; D016012:Poisson Distribution; D013499:Surface Properties; D014465:Ultrasonics / Q000379:methods*; D014783:Viscosity
chemical_list: D003287:Contrast Media; D010969:Plastics; D000535:Aluminum