## 3 Results
### Depth of the Mean Vaporization and Coagulation Zone at a Laser Power of 120 W  
With direct contact to the lung and a motion speed of 5 mm/s, a mean depth of the vaporization zone of \(2126.0\pm 1.4\) um and \(450.5\pm 1.8\) um was determined. At a distance of 5 mm of the tip of the bare fiber to the lung we measured a vaporization zone of \(994.7\pm 1.8\) um and a coagulation zone of \(223.2\pm 2.1\) um. When the distance was doubled to 10 mm, the size of the vaporization zone was \(408.0\pm 1.2\) um and the depth of the coagulation zone was \(66.96\pm 2.4\) um. When increasing the motion speed to 10 mm/s, with direct contact of the bare fiber with the lung, the mean depth of the vaporization zone was \(1514.0\pm 1.7\) um and that of the coagulation zone was \(263.1\pm 2.8\) um. When the distance of the tip of the bare fiber was increased to 5 mm, the mean depth of the vaporization zone was measured  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Motion Speed (mm/s)/Distance of the** & **Vaporization Zone (μm)** & **Coagulation Zone (μm)** \\
**Bare Fiber to the Lung Surface (mm)** & **Vaporization Zone (μm)** & **Coagulation Zone (μm)** \\ \hline
**5/0** & \(1411.0\pm 2.3\) & \(324.3\pm 1.8\) \\
**5/5** & 0 & \(164.9\pm 1.6\) \\
**5/10** & 0 & \(49.0\pm 1.6\) \\
**10/0** & \(777.0\pm 0.9\) & \(211.3\pm 1.7\) \\
**10/5** & 0 & \(101.5\pm 1.3\) \\
**10/10** & 0 & \(5 as \(764.5\pm 0.6\)\(\upmu\)m and that of the coagulation zone as \(126.5\pm 2.2\)\(\upmu\)m. At a distance of 10 mm we measured a mean depth of the vaporization zone of \(287.8\pm 0.7\)\(\upmu\)m and a depth of the coagulation zone of \(63.7\pm 2.4\)\(\upmu\)m.  
After further increasing the motion speed to 20 mm/s, with direct contact of the tip of the bare fiber, we measured a mean depth of the vaporization zone of \(863.1\pm 1.7\)\(\upmu\)m and a mean depth of the coagulation zone of \(102.2\pm 2.4\)\(\upmu\)m. When the distance of the tip of the bare fiber was increased to 5 mm, the depth of the vaporization zone was decreased to \(425.9\pm 1.3\)\(\upmu\)m and that of the coagulation zone to \(64.2\pm 2.3\)\(\upmu\)m. At a distance of 10 mm, the depth of the vaporization zone was decreased to \(182.9\pm 1.5\)\(\upmu\)m and that of the coagulation zone was decreased to \(38.3\pm 1.3\)\(\upmu\)m (see Table 3).  
In summary the Figures 2 and 3 will show the comparison of the depths of vaporization and coagulation zones at various laser powers, motion speeds and distances of the tip of the bare fibre to the lung surface.  
Figure 3: Comparison of the depth of the coagulation zone (in \(\upmu\)m) at the various laser powers (**A**: 20 W, **B**: 60 W, **C**: 120 W), motion speeds (5 mm/s, 10 mm/s, and 20 mm/s) and distances of the tip of the bare fiber to the lung surface (0, 5 mm and 10 mm).  
Figure 2: Comparison of the depth of the vaporization zone (in \(\upmu\)m) at the various laser powers (**A**: 20 W, **B**: 60 W, **C**: 120 W), motion speeds (5 mm/s, 10 mm/s, 20 mm/s) and distances of the tip of the bare fiber to the lung surface (0, 5 mm and 10 mm).  
The histological analysis of the resected preparations exhibited the vaporization effects on the one hand, with varying intensities of the bordering coagulation zones. The surrounding lung parenchyma exhibited no changes owing to the laser. In Figure 4, we show examples of three histological sections in which the effect of increasing the distance of the tip of the bare fiber to the lung surface is easy to recognize. In spite of a consistently high laser power of 120 W, we observed a marked reduction in the vaporization and coagulation zone simply by increasing the distance of the tip of the bare fiber from 5 mm to 10 mm.