Calculation of the kinetics of heating and structural changes in the cartilaginous tissue under the action of laser radiation

Journal Article · Fri Jul 31 00:00:00 EDT 1998 · Quantum Electronics (Woodbury, N.Y.)

DOI:https://doi.org/10.1070/QE1998V028N07ABEH001281· OSTI ID:21437783

Sobol', E N; Kitai, M S ^[1]

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1. Institute of Laser and Information Technologies, Russian Academy of Sciences, Troitsk, Moscow Region (Russian Federation)

A theoretical model is developed for the calculation of the temperature fields and determination of the size of a zone with structural changes in the cartilaginous tissue. The model is based on a simultaneous analysis of the heat and mass transfer processes and it takes into account the bulk absorption of laser radiation by the tissue, surface evaporation of water, and temperature dependences of the diffusion coefficients. It is assumed that under the influence of a phase transition between free and bound water, caused by heating of the cartilage to 70{sup 0}C, the proteoglycans of the cartilage matrix become mobile and, as a result of such mass transfer, structural changes are induced in the cartilaginous tissue causing relaxation of stresses or denaturation. It is shown that the maximum temperature is then reached not on the irradiated surface but at some distance from it, and that the size of the zones of structural changes (denaturation depth) depends strongly on the energy density of the laser radiation and its wavelength, on the duration of the irradiation, and on the cartilage thickness. This model makes it possible to calculate the temperature fields and the depth of structural changes in laser-induced relaxation of stresses and changes in the shape of the cartilaginous tissue. (interaction of laser radiation with matter)

• OSTI ID: 21437783
• Journal Information: Quantum Electronics (Woodbury, N.Y.), Vol. 28, Issue 7; Other Information: DOI: 10.1070/QE1998v028n07ABEH001281; ISSN 1063-7818
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
CARTILAGE
DIFFUSION
ENERGY DENSITY
EVAPORATION
HEATING
KINETICS
LASER RADIATION
MASS TRANSFER
RELAXATION
STRESSES
SURFACES
TEMPERATURE DEPENDENCE
THICKNESS
WATER
WAVELENGTHS
ANIMAL TISSUES
BODY
CONNECTIVE TISSUE
DIMENSIONS
ELECTROMAGNETIC RADIATION
HYDROGEN COMPOUNDS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
RADIATIONS
SORPTION