Injury Thresholds for Topical Cream-Coated Skin of Hairless Guinea Pigs (Cavia Procellus) in Near Infrared Region
Technical rept. for Nov 2005-Dec 2006
NORTHROP GRUMMAN CORP SAN ANTONIO TX INFORMATION TECHNOLOGY
Pagination or Media Count:
The reflectance and absorption of the skin plays a vital role in determining how much radiation will be absorbed by human tissue. Any substance covering the skin would change the way radiation is reflected and absorbed and thus the extent of thermal injury. Hairless guinea pigs cavia porcellus in vivo were used to evaluate how the minimum visible lesion threshold for single-pulse laser exposure is changed with a topical agent applied to the skin. The ED50 for visible lesions due to an Er glass laser at 1540 nm with a pulse width of 50 ns was determined, and the results were then compared to the Takata skin model. The ED50 is compared with the damage threshold of skin coated with a highly absorbing topical cream at 1540 nm to determine its effect on damage pathology and threshold. The ED50 for the guinea pig was then compared to similar studies using Yucatan minipigs and Yorkshire pigs at 1540 nm and nanosecond pulse duration 1, 2. The damage threshold at 24 hours of a Yorkshire pig for a 2.5-3.5 mm spot size diameter beam for 100 ns was 3.2 Jsq cm was very similar to our ED50 of 3.00 Jsq cm for the hairless guinea pigs.
- Anatomy and Physiology
- Physical Chemistry
- Electricity and Magnetism