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Journal of Biomedical Optics • Open Access

Injury depth control from combined wavelength and power tuning in scanned beam laser thermal therapy
Author(s): Martin L. Villiger; Andrew Z. Soroka; Guillermo J. Tearney; Brett E. Bouma; Benjamin J. Vakoc

Paper Abstract

Laser thermal therapy represents a possible method to treat premalignant epithelial lesions of the esophagus. Dynamically conforming the thermal injury profile to a specific lesion boundary is expected to improve the efficacy of such a treatment and avoid complications. In this work, we investigated wavelength tuning as a mechanism to achieve this aimed control over injury depth by using the strong variation of water absorption close to 1900 nm. We developed a numerical model simulating in steps the photon propagation in the tissue, the diffusion of the absorbed heat, and the resulting tissue damage. The model was compared with experimental results on porcine esophageal specimens ex vivo and showed good agreement. Combined with power tuning, the wavelength agility in the range of 1860 to 1895 nm extends the injury range compared to a fixed wavelength source beyond 1 mm, while at the same time improving control over shallow depths and avoiding vaporization at the tissue surface. The combination of two or three discrete wavelengths combined at variable ratios provides similar control, and may provide an improved strategy for the treatment of endothelial lesions.

Paper Details

Date Published: 1 November 2011
PDF: 10 pages
J. Biomed. Opt. 16(11) 118001 doi: 10.1117/1.3647581
Published in: Journal of Biomedical Optics Volume 16, Issue 11
Show Author Affiliations
Martin L. Villiger, Wellman Ctr. for Photomedicine (United States)
Andrew Z. Soroka, Wellman Ctr. for Photomedicine (United States)
Guillermo J. Tearney, Wellman Ctr. for Photomedicine (United States)
Brett E. Bouma, Wellman Ctr. for Photomedicine (United States)
Benjamin J. Vakoc, Wellman Ctr. for Photomedicine (United States)


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