Significance: Water is a primary absorber of infrared (IR) laser energy, and urinary stones are immersed in fluid in the urinary tract and irrigated with saline during IR laser lithotripsy. Laser-induced vapor bubbles, formed during lithotripsy, contribute to the stone ablation mechanism and stone retropulsion effects. Aim: Introduction of a surfactant may enable manipulation of vapor bubble dimensions and duration, potentially for more efficient laser lithotripsy. Approach: A surfactant with concentrations of 0%, 5%, and 10% was tested. A single pulse from a thulium fiber laser with wavelength of 1940 nm was delivered to the surfactant through a 200-μm-core optical fiber, using a wide range of laser parameters, including energies of 0.05 to 0.5 J and pulse durations of 250 to 2500 μs. Results: Bubble length, width, and duration with surfactant increased on average by 29%, 17%, and 120%, compared with water only. Conclusions: Our study demonstrated successful manipulation of laser-induced vapor bubble dimensions and duration using a biocompatible and commercially available surfactant. With further study, use of a surfactant may potentially improve the “popcorn” technique of laser lithotripsy within the confined space of the kidney, enable non-contact laser lithotripsy at longer working distances, and provide more efficient laser lithotripsy.

中文翻译：

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用于碎石术应用的表面活性剂增强的激光诱导蒸汽泡的动力学特性

意义：水是红外线 (IR) 激光能量的主要吸收体，在红外线激光碎石术期间，尿路结石会浸入尿路中的液体中并用生理盐水冲洗。碎石过程中形成的激光诱导蒸汽泡有助于结石消融机制和结石后退效应。目的：表面活性剂的引入可以控制蒸汽泡的尺寸和持续时间，有可能实现更有效的激光碎石术。方法：测试了浓度为 0%、5% 和 10% 的表面活性剂。来自波长为 1940 nm 的铥光纤激光器的单脉冲通过 200 μm 芯光纤传输到表面活性剂，使用范围广泛的激光参数，包括 0.05 到 0.5 J 的能量和250 到 2500 的脉冲持续时间微秒。结果：气泡长度、宽度、与仅使用水相比，使用表面活性剂的持续时间平均增加了 29%、17% 和 120%。结论：我们的研究表明，使用生物相容性和市售表面活性剂成功地控制了激光诱导的蒸汽气泡尺寸和持续时间。随着进一步研究，表面活性剂的使用可能会改善肾脏有限空间内激光碎石的“爆米花”技术，使非接触式激光碎石能够在更长的工作距离下进行，并提供更有效的激光碎石。