Development for medical surgical system with function variability and flexible delivery using dual-wavelength infrared fiber laser

摘要

We developed a medical surgical system with function variability and flexible delivery of dual-wavelength infrared fiber laser that simultaneously oscillated 3 and 2 μm radiation. We studied the function variability (cutting/coagulation) of this fiber laser using a specially designed filter which contained two adjacent areas with different transmission for 2 μm radiation. When the power of 3μm radiation was set to 0.6 W and the power of 2 μm radiation was changed from 0 W to 0.77 W using this filter at the beam traveling speed of 0.25 mm/s, the cutting groove formed in myocardium tissue increased from 0.80 mm to 0.89 mm and the coagulation layer thickness increased from 0.41 mm to 0.85 mm. We successfully developed a filter system that could continuously control coagulation layer thickness with cutting capability constant. We studied a flexible beam delivery using a single crystal sapphire fiber. The transmission efficiency per meter for 3 and 2 μm radiation using a 200-μm core-diameter sapphire fiber was 58.0 % and 60.4 %, respectively. The bending loss at 3-cm loop radius was 5.6 %. The high flexibility and low bending loss of the sapphire fiber might make it possible to apply the dual-wavelength infrared fiber laser to endoscopic treatment. In summary, these results may encourage the possibility for practical use of the fiber laser.