| Abstract: | Thermal relaxation times of blood vessels associated with port wine stains (PWS), when these vessels are subjected to laser irradiation, are estimated as a function of their diameter. The heat conduction equation with boundary conditions of the first kind is solved exactly, in order to find the temperature distribution inside the vessel. An approximate solution giving data appropriate for clinical applications is found. For the range in diameters of the blood vessels involved, it is found that the relaxation times are, approximately, in the range 0.10–15 ms. In the case of a typical 50 μm diameter vessel, it is found that the cooling process is essentially completed after 3.85 ms. |
