Influence of laser wavelength and beam profile on the coagulation depth in a soft tissue phantom model
| Autor: | Mirko Aden, Patricia Betz, Martin Wehner |
|---|---|
| Přispěvatelé: | Publica |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Optical Phenomena Quantitative Biology::Tissues and Organs Physics::Medical Physics Dermatology Radiation Imaging phantom Quantitative Biology::Cell Behavior law.invention 030207 dermatology & venereal diseases 03 medical and health sciences 0302 clinical medicine Optics law Thermal Computer Simulation Laser Coagulation Phantoms Imaging business.industry Scattering Lasers Signal Processing Computer-Assisted 030206 dentistry Penetration (firestop) Models Theoretical Laser Wavelength Surgery business Gaussian beam |
| Zdroj: | Lasers in Medical Science. 34:335-341 |
| ISSN: | 1435-604X 0268-8921 |
| DOI: | 10.1007/s10103-018-2598-2 |
| Popis: | In laser tissue soldering (LTS), a protein solution is thermally denatured and cross-linked to obtain a strong bond between tissues or tissue and a wound dressing. However, if the extension of the heat-affected zone is too large, wound healing is impaired by thermal tissue injuries. Therefore, heat input and coagulation depth have to be limited. We investigate the influence of wavelength and beam profile on coagulation depth using a soft tissue phantom in case of weakly (980 nm) and strong (1540 nm) absorbed laser radiation. The soft tissue phantom is doped with polystyrene (PS) beads to obtain similar scattering properties as natural tissue. The propagation of the laser radiation in the phantom is simulated by Monte-Carlo method and the optical penetration (OPD) depth calculated from isophotes. The simulation results are compared with the experimental determination of the coagulation volume. The results reveal that scattering effect of tissues on laser radiation increases the losses of a Gaussian beam profile laterally leading to a half-sphere coagulation volume. The depth profile of the coagulation follows approximately the intensity distribution of the laser beams as long as scattering effects are weak. As scattering effects become significant, as for 980-nm radiation, the intensity distribution of the laser beam in the tissue deviates from the original one, leading to different profile of the coagulation depth. |
| Databáze: | OpenAIRE |
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