Size-dependent translational velocity of phospholipid-coated bubbles driven by acoustic radiation force

Abstract

This study investigates how the translational velocity of phospholipid-coated bubbles caused by acoustic radiation force depends on their size. The translations of bubbles with mean radii of 0.9 – 5 μm were experimentally evaluated at five ultrasound frequency conditions (3.5, 5, 7.5, 10, and 15 MHz). We compared experimental data with theoretical prediction using a viscoelastic interfacial rheological model and a model suitable for high amplitude oscillation. The results suggested that the translation of bubbles could be enhanced for a mean radius of 1 – 3 μm but echo intensity could not.

Experimental conditions for efficient retention of vascular endothelial cells on channel wall using lipid bubbles and acoustic interference

“…Because our group has been researching a method for actively controlling cells using a microbubble [8][9][10][11][12] and ultrasound, we considered applying this novel technique to the fabrication of multilayered construction of the cells, such as artificial vessels with multiple bifurcations. By forming a bubble-surrounded cell (BSC), in which the microbubbles are attached to the surface of a core cell, the dynamics of the cells contained in BSCs are controlled under ultrasound exposure.…”

Pseudo-Doppler effect at a disappearance of a single microbubble translating owing to acoustic radiation force

“…[11][12][13] We have fabricated lipid MBs with an indocyanine green derivative as a contrast agent for ultrasound and near-infrared fluorescence dual imaging, 14) and proposed the method to detect MBs with high sensitivity by actively moving them using acoustic radiation force. [15][16][17] This technique, which is named the contrast-enhanced active Doppler method (CEADUS), would improve the robustness of visualization of vessels with stationary fluid, e.g. lymph vessels, which conventional contrast-enhanced Doppler ultrasound hardly detects.…”

“…Previous studies characterized the translation of MBs in various conditions for ultrasound transmission and bubble size. [17][18][19] Several tens or hundreds of pulses must be repeatedly exposed to induce the detectable translation of MBs. The application of plane wave imaging to CEADUS effectively shortens the time required for consecutive transmissions while maintaining a better contrast ratio.…”