Analytical solutions of non-Fourier bio-heat conductions for skin subjected to pulsed laser heating

The analytical solutions of bio-heat transfer for skin tissue with general boundary conditions in the Pennes, Cattaneo-Vernotte (C-V) and Dual-phase-lag (DPL) models are presented. The heat transfer of skin subjected to the pulse laser heating and fluid cooling are studied. In the conventional literature, the inner boundary of skin will be assumed to be in the constant temperature condition or the isolated condition and their numerical difference is discussed here. The effects of the phase lags with respect to heat flux and temperature gradient on the thermal wave speed are investigated. The comparison of the presented results and the approximated speed formula, k/τqρc, in the C-V model is made. The skin damage index in several damage models by pulsed laser heating is discussed. Later, the discussion of effects of several boundary conditions on temperature variation and thermal damage in the Pennes, CV and DPL models is introduced. It is found that the procedure including pulsed heating and cooling creates the temperature fluctuation of skin. It is suitable for the cold and heat therapy for pain relief and other functions. The conditions of pulsed heating skin and simultaneous cooling for the thermal therapy are investigated. The analytical method can be widely applied for solving the general problem of heat conduction.