Plasma-induced ablation for removal of tissue

number: 
3227
إنجليزية
Degree: 
Author: 
Media Fadhil Jalil Baqqal
Supervisor: 
Dr.Ziad T.Al-Dahan
year: 
2014
Abstract:

Plasma-induced ablation, a very clean and well defined removal of tissue without evidence of thermal or mechanical damage can be achieved when choosing appropriate laser parameters. The high-energy, short-pulse scan carbon dioxide (CO2) laser became the most popular method utilized for these purposes. The laser-skin interaction was studied using the rabbit skin as an experimental sample and 10.6 μm wavelength CO2 laser as a source of irradiation. This study aimed to determine the effect of different laser power doses on the skin structure as a trial to understand how laser exerts its medical effects in treating skin problems. It also aimed to determine the relationship between the laser power density and depth of ablated skin and its biological effects. Briefly, the rabbit skin was exposed to suprapulse CO2 laser of 200 microsecond pulse width and 5 ~ 16 W power for 1 second. The experimental hosts were divided into two groups, biopsies of normal and exposed skin were taken directly after the exposure in the first group, and 4 days post exposure in the second group, the biopsies have been preserved and fixed for histological studies. The images obtained from the histological slides were examined via a compound light microscope provided with a special program to measure the ablation depths in the skin surface. Removing the outer skin layers to the papillary dermis level induces re-epithelialisation and new collagen formation, which can create a smoother, even-toned, and more youthful appearance. The computed results from the mathematical blow-off model are then compared with experimental measurements of ablation depths in skin. The model is found to be in good agreement with experiment.