The use of 2.09 μm Ho-YSGG laser pulses for intra-vascular non-contact ablation of tissue has been investigated. Therefore the transmission and the temporal shape of the laser pulse transmitted through saline was measured. Also the interaction between the laser pulses (200 μs FWHM) and saline was studied by time resolved flash photography. Finally, porcine aorta was ablated (in vitro) through either blood or saline. The lesions and adjacent tissue were examined histologically. The penetration depth (the depth for a decrease to 1/e of the transmitted energy) of the laser pulses in saline depended on the power density (0.01 to 12.4 J/mm2) and varied from 0.33 to 2.2 mm, respectively. The photography showed the development of a transparent water vapor cavity around the fiber tip (320 μm) during the laser pulse. The maximum dimensions of the cavity varied as function of the intensity. Within the vapor cavity the laser pulse was undisturbed.
|Number of pages||6|
|Journal||Proceedings of SPIE - the international society for optical engineering|
|Publication status||Published - 1 Jan 1991|
|Event||2nd Laser-Tissue Interaction Conference 1991 - Los Angeles, United States|
Duration: 21 Jan 1991 → 23 Jan 1991
Conference number: 2