Q开关Nd:YAG 1064nm和532nm激光对犬心肌切割作用的研究

目的 :研究 10 64nm和 53 2nm波长激光在激光能量为 14 0mJ/pulse(脉冲 )时对犬心肌切割效率。方法 :用Q开关Nd :YAG 10 64和 53 2nm波长脉冲激光分别照射犬离体和在体心肌组织 ,光学显微镜和偏振光学显微镜行组织学分析 ,观察不同条件下激光切割组织的深度和光热对组织的损伤。结果 :离体和在体实验 ,10 64nm波长激光的切割效率高于 53 2nm(p <0 .0 1)。在体和离体实验显示 10 64nm激光能量和重复率相同时 ,所致的切割效率无明显差异 (p >0 .0 5) ,血液对 10 64nm激光的切割效率影响较小。相反 ,在 53 2nm时血液对其影响较大 ,相同的激光能量和重复率 ,离体实验切割效率高于在体 (p <0 .0 1)。 10 64nm激光所致的光热和机械损伤均轻于 53 2nm激光。结论 :在切割效率方面 ,10 64nm激光比 53 2nm更适用于TMLR。 10 64nmQ开关Nd :YAG激光可通过光导纤维传输 ,是TMLR的一个有潜力的激光源

Study of the Effect of Q-switch Nd:YAG Laser Irradiation with Wavelength of 1064nm and 532nm on Canine Myocardium

Objective: To investigated ablation efficiency of canine myocardium with Q switch laser with 1064nm and 532nm at laser power 140mJ/pulse. Methods: To irradiate canine myocardium in vitro and in vivo with Q switch laser with 1064nm and 532nm. For the ablated tissue samples, histological analysis was performed with an optical microscope and a polarization microscope, laser induced ablation depth at various condition was compared and thermal damage was observed at 532nm. Result: For ablation of myocardium in vivo and in vitro, the ablation efficiency at 1064nm was higher than that at 532nm. With the 1064nm laser, the blood have a little influence upon the ablation characteristics, no significant difference of ablation efficiency was found between in vivo and in vitro ablation at similar laser energy and repetition (p>0.05). To the contrary, ablation efficiency was influenced considerably by the existence of blood when the 532nm laser was used, for experiment in vivo, ablation efficiency was higher than that in vitro at similar laser energy and repetition (p<0.01). The optical thermal and mechanical damage for tissues in the 1064nm laser ablated tissue is smaller than that in the 532nm laser ablated tissue. Conclusion: With regard to the ablation efficiency, the 1064nm laser was more suitable for TMLR than the 532nm laser. 1064nm Q switched Nd:YAG laser would be a potential candidate for a laser source for TMLR because of possible fiber based beam delivery.