With 1064-nm, nanosecond laser pulses delivered from hollow waveguide, ablation characteristics of porcine myocardium tissue have been investigated in vitro. For the hollow waveguide a vacuum-cored scheme was introduced to suppress the laser-induced air breakdown that limited the available transmitted laser energy/power. The delivered laser pulse beam was focused with a collimation lens and a focusing lens, and it was shown that higher efficiency ablation was obtained when a focusing lens with a shorter focal length was used. Waveguide bending (bending angle 90°, bending radius ∼ 50 cm) caused no deteriorating effect on the ablation characteristics for ablation energies up to ∼ 60 mJ/pulse. It was demonstrated that deep and sharp ablated holes with aspect ratios > 8 was obtained with the hollow-waveguide-delivered laser pulses. It may be a realistic option to aim at using the present hollow waveguide system for trocar-based applications or replacing articulated mirror-based laser delivery systems. It is an important part of the future works to downsize the waveguide output unit for catheter-based applications.
|ジャーナル||Proceedings of SPIE - The International Society for Optical Engineering|
|出版ステータス||Published - 2001 1月 1|
|イベント||Optical Fibers and Sensors for Medical Applications - San Jose, CA, United States|
継続期間: 2001 1月 20 → 2001 1月 21
ASJC Scopus subject areas
- コンピュータ サイエンスの応用