Development of Laser Therapy Apparatus using Minute Spot Scanning Method

Abstract

To remove unwanted pigments in the skin laser light is irradiated on the pigmented lesion. Melanin, locally existing in skin, selectively absorbs the laser light. At present, the laser guns used in dermatology are manually operated and their laser spots are as large as 3 to 7 mm in diameter. It is thought that normal tissues, which don't contain melanin so much, are hardly damaged by the laser irradiation. But in reality, terrible burns appear after laser irradiation even in the normal tissue. We have developed a new type of laser apparatus for removing pigmented lesions with laser focusing and laser scanning technology. The fΘlens unit assembled by a shrink fitter can focus the laser beam well over a wide scanning width. Thus, the intensity of the focused laser beam became high enough even with a low-power laser oscillator. The focused laser irradiation lead also to another advantage. The cooling rate of the lesion, whose temperature rises over a given point by the focused laser beam, was increased. The effect of the focused laser irradiation on the pigmentation therapy was experimentally examined with the developed apparatus.