Preclinical evaluation of porcine colon resection using hollow core negative curvature fibre delivered ultrafast laser pulses.

Figure 1 Schematic representation of colon tissue layers.Figure 2 Schematic of the laser system for fibre delivered pulses for tissue resection Figure 3 Schematic of the laser system for direct laser resection of tissue a) Schematic of the spiral scan pattern at the colon tissue surface during picosecond laser ablation Figure 4 Seven cell NC-HCF fibre (a) cleaved laser launching surface (b) damaged surface (c) image of light confined in a single mode at the end face of HC-NCF (20x zoomed image) (d) single mode beam at the focus of 20 mm focal length lens (20x zoomed image) placed after the HC-NCF. Figure 5 coupling efficiency plot of 7 cell HC-NCF Figure 6 Autocorrelation traces of picosecond laser beam (FWHM = 6ps) with an input pulse energy of ~42 µJ corresponding to ~29 µJ delivered from the output of the HC-NCF (Blue line) showing no significant pulse broadening. Figure 7 Optical spectra of laser beam of 6 ps pulse width and 42 µJ pulse energy. 1.5 meter long HC-NCF delivered beam with 6 ps pulse width and ~29 µJ pulse energy (blue line). Figure 8 (a) and (b) Three-dimensional surface profile of the laser ablated zone, (c) and (d) orthogonal depth profiles of the same crater. Figure 9 Haemotoxylin and eosin (H&E) stained images and 3D profilometric images of laser ablated zones in different tissues using same laser parameters. The applied laser fluences are a & c) 18 J/cm2 b & d) 13 J/cm2 Figure 10 The 3D profilometric image of laser ablated area using HC-NCF delivered pulses on porcine colon samples and histology results of laser ablated area in different tissue sample with same laser parameters a) 21 J/cm2 b) 14 J/cm2 and c) 7 J/cm2 laser fluences. The black line on the image is an artefact after the preparation of sample for histology. The expanded view of maximum thermal damage in each laser ablated tissue is presented in the bottom.

图1 结肠组织层结构示意图。图2 用于光纤传输脉冲以实施组织切除的激光系统示意图。图3 用于组织直接激光切除的激光系统示意图：(a) 皮秒激光烧蚀过程中结肠组织表面的螺旋扫描模式示意图。图4 七单元负曲率空芯光纤（Negative Curvature Hollow-Core Fiber, NC-HCF）：(a) 经切割的激光入射端面；(b) 受损端面；(c) HC-NCF端面处单模束缚光的成像（20倍放大图像）；(d) 放置于HC-NCF之后的20 mm焦距透镜焦点处的单模光束（20倍放大图像）。图5 七单元HC-NCF的耦合效率曲线。图6 皮秒激光束的自相关轨迹：半高全宽（Full Width at Half Maximum, FWHM）=6 ps，输入脉冲能量约42 μJ，经HC-NCF输出后脉冲能量约29 μJ（蓝色曲线），未出现显著脉冲展宽。图7 脉宽6 ps、脉冲能量42 μJ的激光束光谱，以及经1.5米长HC-NCF传输后的光束光谱（脉宽6 ps、脉冲能量约29 μJ，蓝色曲线）。图8 (a)与(b) 激光烧蚀区域的三维表面轮廓，(c)与(d) 同一烧蚀凹坑的正交深度轮廓。图9 采用相同激光参数在不同组织上实施激光烧蚀后的苏木精-伊红（Haematoxylin and Eosin, H&E）染色图像与三维轮廓测量图像。所用激光能量密度分别为：(a与c) 18 J/cm²，(b与d) 13 J/cm²。图10 采用HC-NCF传输脉冲在猪结肠样本上进行激光烧蚀区域的三维轮廓测量图像，以及采用相同激光参数在不同组织样本上开展激光烧蚀区域的组织学检测结果：(a) 21 J/cm²、(b) 14 J/cm²、(c) 7 J/cm²激光能量密度。图像中的黑色线条为组织学样本制备过程中产生的伪影。各激光烧蚀组织的最大热损伤放大视图展示于图下方。