15 April 2005 ED50 study of femtosecond terawatt laser pulses on porcine skin
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We report on our measurements of the Minimum Visible Lesion (MVL) thresholds for porcine skin [Yucatan mini-pig (Sus scrofa domestica)] for laser exposures at 810 nm and sub-50 femtosecond (fs) laser pulses. In this study we measured the ED50 skin thresholds from laser pulses that produced multiple self-focusing filaments while propagating from the laser to the skin. These high-powered (1-2 terawatt) filaments were focused on the flank of mini-pig and three trained readers determined the number of lesions becoming visible at 1-hour and 24-hour post-exposure. The observed damage patterns on the skin surface indicated the number of filaments in the laser pulse and these were photographed for future reference. Histological sections were obtained after both readings and the results will be reported later for sub-surface damage. The threshold using preliminary data at 1-hour was 9 mJ of energy and increased to 25 mJ after 24 hours. This increase in threshold indicated that many of the laser pulses produced only superficial damage (erthemia) that disappeared in 24 hours and that nearly 3 times the pulse energy was required to cause subsurface or cellular damage.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Semih Kumru, Semih Kumru, Clarence P. Cain, Clarence P. Cain, Gary Noojin, Gary Noojin, Michelle Imholte, Michelle Imholte, Duane Cox, Duane Cox, Carrie Crane, Carrie Crane, Benjamin Rockwell, Benjamin Rockwell, "ED50 study of femtosecond terawatt laser pulses on porcine skin", Proc. SPIE 5695, Optical Interactions with Tissue and Cells XVI, (15 April 2005); doi: 10.1117/12.585036; https://doi.org/10.1117/12.585036

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