Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48105, USA.
J Acoust Soc Am. 2023 Jan;153(1):237. doi: 10.1121/10.0016849.
A 700 kHz histotripsy array is used to generate repeated cavitation events in agarose, gelatin, and polyacrylamide hydrogels. High-speed optical imaging, a broadband hydrophone, and the narrow-band receive elements of the histotripsy array are used to capture bubble dynamics and acoustic cavitation emissions. Bubble radii, lifespan, shockwave amplitudes are noted to be measured in close agreement between the different observation methods. These features also decrease with increasing hydrogel stiffness for all of the tested materials. However, the evolutions of these properties during the repeated irradiations vary significantly across the different material subjects. Bubble maximum radius initially increases, then plateaus, and finally decreases in agarose, but remains constant across exposures in gelatin and polyacrylamide. The bubble lifespan increases monotonically in agarose and gelatin but decreases in polyacrylamide. Collapse shockwave amplitudes were measured to have different-shaped evolutions between all three of the tested materials. Bubble maximum radii, lifespans, and collapse shockwave amplitudes were observed to express evolutions that are dependent on the structure and stiffness of the nucleation medium.
一个 700 kHz 的 histotripsy 阵列被用来在琼脂糖、明胶和聚丙烯酰胺水凝胶中产生重复的空化事件。高速光学成像、宽带水听器和 histotripsy 阵列的窄带接收元件被用来捕获气泡动力学和超声空化发射。气泡半径、寿命、冲击波幅度被注意到在不同的观察方法之间有很好的一致性。对于所有测试的材料，这些特性也随着水凝胶刚度的增加而降低。然而，在不同的材料主体中，这些特性在重复辐射期间的演变差异很大。在琼脂糖中，气泡的最大半径最初增加，然后达到稳定，最后减小，但在明胶和聚丙烯酰胺中的暴露则保持不变。在琼脂糖和明胶中，气泡寿命单调增加，但在聚丙烯酰胺中则减小。在所有三种测试材料中，测量到的坍塌冲击波幅度都具有不同的形状演变。气泡最大半径、寿命和坍塌冲击波幅度的演变被观察到与成核介质的结构和刚度有关。
