Computer aided design, preparation and experimental study on encapsulated microbubbles

To study the effects of structural parameters on encapsulated microbubbles' subharmonic characterization and to optimize these parameters to prepare microbubbles suitable for subharmonic imaging, a theoretical model for the oscillation of encapsulated microbubbles in ultrasound field was employed to develop a computer aided design system which was used to analyze the effects of structure and acoustic parameters on subharmonic responses of the micro-bubbles. Microbubbles with different size distributions were prepared by size fractioning, and their quantitative acoustic properties were measured in vitro. Theoretical simulation and acoustic measurement showed that subharmonic enhancement could be observed with microbubbles in vitro and numerically at the transmitted frequency of 5 MHz by controlling the size distribution. Larger microbubbles showed higher subharmonic enhancement than non-fractioned ones. The subharmonic characterization of encapsulated microbubbles can be optimized by means of this computer aided design system. Thus desired microbubbles can be prepared with the aid of this system.