Giglio Nicholas C, Grose Haleigh M, Fried Nathaniel M
University of North Carolina, Department of Physics and Optical Science, Charlotte, North Carolina, United States.
University of North Carolina, Department of Mechanical Engineering, Charlotte, North Carolina, United States.
Opt Eng. 2022 Feb;61(2). doi: 10.1117/1.oe.61.2.026112. Epub 2022 Feb 26.
Infrared lasers may provide faster and more precise sealing of blood vessels and with lower device jaw temperatures than ultrasonic and electrosurgical devices during surgery. Our study explores three beam shaping methods using optical fibers for transformation of a circular laser beam into a linear beam, necessary for integration into a standard 5-mm-diameter laparoscopic device, and for uniform irradiation perpendicular to the vessel length. In the first design, a servo motor connected to a side-firing, 550-m-core fiber, provided linear translation of a 2.0-mm-diameter circular beam, back, and forth, over either 5 or 11 mm scan lengths for sealing of small or large vessels. The second design used external beam splitters to divide laser power equally into three side-firing fibers, stacked side-by-side, producing a linear beam of 4 × 2 mm. The third design used external beam splitters with three forward-firing fibers and a slanted jaw surface, to produce a linear beam of 5 × 1.5 mm. Laser seals were performed, , on 41 porcine renal arteries of 1- to 6-mm diameter ( ≥ 10 samples for each design). Each vessel was compressed to a fixed 0.4-mm-thickness, matching the optical penetration depth at 1470 nm. Vessels were irradiated with fluences of 636 to 800 J/cm, which, based on previous studies, is sufficient for sealing, but not cutting. A burst pressure setup was used to evaluate vessel seal strength. Reciprocating fiber and fiber bundles produced mean burst pressures of 554 ± 142, 524 ± 132, 429 ± 99, and 390 ± 140 mmHg, respectively. All designs consistently sealed blood vessels, with burst pressures above hypertensive (180 mmHg) blood pressures. The reciprocating fiber produced the most uniform linear beam profile and aspect ratio but will require integration of the servo motor into a handpiece. Fiber bundle designs produced shorter, less uniform beams, but enable optical components to be assembled outside the handpiece.
在手术过程中，红外激光可能比超声和电外科设备能更快、更精确地封闭血管，且设备钳口温度更低。我们的研究探索了三种使用光纤的光束整形方法，用于将圆形激光束转换为线性光束，这对于集成到标准的5毫米直径腹腔镜设备中以及垂直于血管长度进行均匀照射是必要的。在第一种设计中，一个与侧面发射的550米芯光纤相连的伺服电机，使直径为2.0毫米的圆形光束在5或11毫米的扫描长度上来回线性移动，以封闭小血管或大血管。第二种设计使用外部光束分离器将激光功率平均分配到三根并排堆叠的侧面发射光纤中，产生一个4×2毫米的线性光束。第三种设计使用带有三根向前发射光纤和一个倾斜钳口表面的外部光束分离器，以产生一个5×1.5毫米的线性光束。对41条直径为1至6毫米的猪肾动脉进行了激光封闭（每种设计≥10个样本）。每条血管被压缩到固定的0.4毫米厚度，与1470纳米处的光学穿透深度相匹配。血管用636至800 J/cm的能量密度进行照射，根据先前的研究，这足以进行封闭但不会切割。使用爆破压力装置来评估血管封闭强度。往复式光纤和光纤束产生的平均爆破压力分别为554±142、524±132、429±99和390±140毫米汞柱。所有设计都能持续封闭血管，爆破压力高于高血压（180毫米汞柱）血压。往复式光纤产生的线性光束轮廓和长宽比最均匀，但需要将伺服电机集成到手持器械中。光纤束设计产生的光束较短且均匀性较差，但能使光学组件在手持器械外部组装。
