激光止血刀匀光系统设计

Design of Light-homogenized System for Laser Scalpel

以激光高聚焦能力实现组织凝结和切割的激光手术刀,适用于可直接接触治疗目标的手术操作,但难以满足腔镜环境下血管凝结或切割在狭长区域上温度分布均匀的需求。为解决上述问题,受侧发光光纤双光源匀光方式的启发,通过棱镜和镀膜的组合,设计了一种虚拟双光源光路,将单根光纤光束调整为侧向条形分布光源,该光源照射金属后利用光热转换进一步改善金属刀头表面温度的均匀性,实现腔镜环境下血管凝结或切割的温度可控。仿真结果表明,通过该光路设计可得到长约14~17mm宽2mm的条形分布光源,金属面的辐照度相对标准偏差约为40%~60%,当波长为980nm的8W激光器照射金属3s时,与组织接触面达到凝结所需温度,温度相对标准偏差为3.55%,验证了腔镜环境下激光热致止血刀的可行性。

Hemostasis and cutting during surgery can be achieved by laser scalpel with the help of its high focusing ability, where the target tissue can be reached directly. However, operations are hardly done by laser scalpel under the endoscope due to the long and narrow aperture. In order to deal with such problems, an optical approach is achieved with virtual dual light sources in this paper. Fiber laser is transformed into a side-emitting strip-shaped light source by two coated prims, and then absorbed by a metal sheet to stop bleeding or cut by heating. Simulations demonstrated that a side-emitting strip light source with length of 14~17 mm and width of 2 mm can be approached, and the relative standard deviation of irradiance on the metal sheet is about 40%~60%. After 3s irradiation of 980 nm laser with power of 8 W, the temperature on the metal sheet surface rises up to coagulate and its relative standard deviation is 3.55%, which demonstrated the feasibility of the laser scalpel for endoscope.