University of North Carolina at Charlotte, Department of Physics and Optical Science, Charlotte, Nor, United States.
University of North Carolina at Charlotte, Department of Mechanical Engineering, Charlotte, North Ca, United States.
J Biomed Opt. 2021 Jan;26(1). doi: 10.1117/1.JBO.26.1.018001.
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.
Introduction of a surfactant may enable manipulation of vapor bubble dimensions and duration, potentially for more efficient laser lithotripsy.
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.
Bubble length, width, and duration with surfactant increased on average by 29%, 17%, and 120%, compared with water only.
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.
水是红外线（IR）激光能量的主要吸收体，在 IR 激光碎石术中，尿路结石浸在尿路中的液体中，并被生理盐水冲洗。激光诱导的蒸汽泡在碎石过程中形成，有助于结石消融机制和结石后退效应。
引入表面活性剂可能能够控制蒸汽泡的尺寸和持续时间，从而提高激光碎石术的效率。
测试了浓度为 0%、5%和 10%的表面活性剂。通过 200-μm 芯光纤将波长为 1940nm 的掺铥光纤激光的单个脉冲传输到表面活性剂，使用广泛的激光参数，包括 0.05 至 0.5J 的能量和 250 至 2500μs 的脉冲持续时间。
与仅用水相比，表面活性剂处理后气泡的长度、宽度和持续时间平均增加了 29%、17%和 120%。
我们的研究成功地使用生物相容性和商业上可获得的表面活性剂来控制激光诱导的蒸汽泡尺寸和持续时间。进一步研究表明，表面活性剂的使用可能会潜在地改善肾结石腔内“爆米花”技术，实现更长工作距离的非接触式激光碎石术，并提供更高效的激光碎石术。
