7 July 1993 Comparative study of pulsed Ho:YAG versus Tm:YAG: impulse-induced pressure in porcine aorta
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Proceedings Volume 1882, Laser-Tissue Interaction IV; (1993) https://doi.org/10.1117/12.147656
Event: OE/LASE'93: Optics, Electro-Optics, and Laser Applications in Scienceand Engineering, 1993, Los Angeles, CA, United States
The goal of this study is to measure the average impulse induced pressure in porcine aorta by one laser pulse for both a free running Tm:YAG (2.014 microns) laser and a free running Ho:YAG (2.1 microns) laser. The pulsed Tm:YAG and Ho:YAG lasers operated at a repetition rate of 2 Hz and a FWHM pulse width of 150 microseconds. The laser energy was delivered to the tissue via a 600 micron core diameter low-OH silica fiber. The impulse pressure induced in the aortic wall was evaluated using tissue samples (n equals 50) mounted on a pendulum to measure the transferred momentum from the laser pulse to the tissue. The impulse induced pressure was determined using a contact mode, where the fiber tip and tissue surface are within 0.5 mm of each other. The impulse induced pressure was studied over a fluence range of 35 - 350 J/cm2, fifteen measurements were taken at each fluence level. The results showed that the average impulse induced pressure of the Ho:YAG pulsed laser in the fiber contact mode was 2 - 6 times greater than in the non-contact mode, where the energy at the fiber tip was imaged onto the tissue surface. The results also showed that both the Ho:YAG and the Tm:YAG average impulse induced pressure, in the contact mode, increased linearly at lower fluences, reaching a peak at approximately 13 - 14 atm.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Wendy J. Snyder, Wendy J. Snyder, Wei-Qiang Shi, Wei-Qiang Shi, Sandor G. Vari, Sandor G. Vari, Warren S. Grundfest, Warren S. Grundfest, "Comparative study of pulsed Ho:YAG versus Tm:YAG: impulse-induced pressure in porcine aorta", Proc. SPIE 1882, Laser-Tissue Interaction IV, (7 July 1993); doi: 10.1117/12.147656; https://doi.org/10.1117/12.147656

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