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The development of a unified theory for the optical and thermal response of tissue to laser radiation is no longer in its infancy, though it is still not fully developed. This book describes our current understanding of the physical events that can occur when light interacts with tissue, particularly the sequence of formulations that estimate the optical and thermal responses of tissue to laser radiation. This overview is followed by an important chapter that describes the basic interactions of light with tissue. Part I considers basic tissue optics. Tissue is treated as an absorbing and scattering medium and methods are presented for calculating and measuring light propagation, including polarized light. Also, methods for estimating tissue optical properties from measurements of reflection and transmission are discussed. Part II concerns the thermal response of tissue owing to absorbed light, and rate reactions are presented for predicting the extent of laser induced thermal damage. Methods for measuring temperature, thermal properties, rate constants, pulsed ablation and laser tissue interactions are detailed. Part III is devoted to examples that use the theory presented in Parts I and II to analyze various medical applications of lasers. Discussions of Optical Coherence Tomography (OCT), forensic optics, and light stimulation of nerves are also included. [ABSTRACT FROM AUTHOR]

Optics for laser irradiation of tissue is best described by examining the response of a target within tissue to light. Suppose tissue (e.g. skin) has a chromophore, (e.g. a melanocyte) somewhere inside the tissue at coordinate ]> with respect to some frame of reference (Fig. 3.1). What is the rate of heat that is generated in the chromophore when the tissue is irradiated at some wavelength with constant power P over the laser beam radius wL? The key question that needs to be answered is: how many photons per second will reach the chromophore and be absorbed. Tissue optics should provide the answer to this question. [ABSTRACT FROM AUTHOR]

The first two parts of this book describe various theories associated with light propagation in tissue and the resulting response. If coherence or polarization information is not needed, we assume that the transport equation governs the optical interaction of light with tissue and the heat conduction equation provides the basis for estimating the thermal response of tissue to laser radiation. In part III of this book, the theory for optical and thermal interactions of laser light with tissue are used to analyze medical applications. In particular, the concepts of parts I and II [ABSTRACT FROM AUTHOR]