Removal of residual cavitation nuclei to enhance histotripsy erosion of model urinary stones.
Removal of residual cavitation nuclei to enhance histotripsy erosion of model urinary stones.
复制标题
去除残余空化核，以增强模型尿石的组织疗法侵蚀。
DOI：
10.1109/tuffc.2015.7001
复制
发表时间：
2015-05
期刊：
影响因子：
--
通讯作者：
Hall TL
中科院分区：
文献类型：
--
作者：
Duryea AP;Roberts WW;Cain CA;Hall TL
组织疗法已被证明是模型肾结石的有效治疗方法，将其表面侵蚀到小小的碎屑，通过腔云，类似于冲击波岩石疗法，组织疗法的结石表现出以低速依赖脉冲的效果与以高速率应用的石材侵蚀产生更有效的石材侵蚀。云倒塌。在组织摄影云中，这些微观的剩余气泡可以持续100 µs，可以持续1秒钟的阶段，从而导致随后的组织疗法脉冲的直接衰减并影响这些效果。 ，我们已经开发了一种新的策略，可以使用低振幅超声脉冲从现场中积极清除剩余的空气核。选择适当的声学参数这些气泡去除脉冲可以刺激微观气泡核的聚集，并从目标体积中删除它们。组织疗法以低速率（1 Hz）应用，气泡去除不会在较高的脉冲下产生统计学上的显着变化10、100和500 Hz的速率增加了气泡的去除量，导致3.7-，7.5-和2.7倍的石材侵蚀增加表明，引入气泡去除脉冲是由高云脉冲引起的。脉搏率更接近以1 Hz的低速率产生的脉搏率。残留的气泡核，并表明可以通过适当操纵石头周围的空化环境以高脉搏率来回收高治疗效率。
Histotripsy has been shown to be an effective treatment for model kidney stones, eroding their surface to tiny particulate debris via a cavitational bubble cloud. However, similar to shock wave lithotripsy, histotripsy stone treatments display a rate-dependent efficacy with pulses applied at low rate generating more efficient stone erosion in comparison to those applied at high rate. This is hypothesized to be the result of residual cavitation bubble nuclei generated by bubble cloud collapse. While the histotripsy bubble cloud only lasts on the order of 100 µs, these microscopic remnant bubbles can persist on the order of 1 second—inducing direct attenuation of subsequent histotripsy pulses and influencing bubble cloud dynamics. In an effort to mitigate these effects, we have developed a novel strategy to actively remove residual cavitation nuclei from the field using low-amplitude ultrasound pulses. Previous work has demonstrated that with selection of the appropriate acoustic parameters these bubble removal pulses can stimulate the aggregation and subsequent coalescence of microscopic bubble nuclei—effectively deleting them from the target volume. Here, we incorporate bubble removal pulses in histotripsy treatment of model kidney stones. It was found that when histotripsy is applied at low rate (1 Hz), bubble removal does not produce a statistically significant change in erosion. At higher pulse rates of 10, 100, and 500 Hz, incorporating bubble removal results in 3.7-, 7.5-, and 2.7-fold increases in stone erosion, respectively. High speed imaging indicates that the introduction of bubble removal pulses allows bubble cloud dynamics resulting from high pulse rates to more closely approximate those generated at the low rate of 1 Hz. These results corroborate previous work in the field of shock wave lithotripsy regarding the ill-effects of residual bubble nuclei, and suggest that high treatment efficiency can be recovered at high pulse rates through appropriate manipulation of the cavitation environment surrounding the stone.