PDF Ebook Hair Removal Using An Nd: YAG Laser System
Coherent and incoherent intense light for hair removal has attracted an incredible amount of attention. This explosion of interest reflects a demand for more tolerable, practical, and effective epilation techniques. A variety of lasers and an intense pulsed light source 67 are presently available for this purpose. One of the lasers currently being used is an Nd:YAG system at 1064 nm. This article reviews the Nd:YAG laser and its role in hair removal.
Neodymium is a faintly yellow, trivalent element classified in the rare earth family of metals. It was discovered in 1885 by C. A. von Welsbach 11 and has an atomic number of 60, an atomic weight of 144.24, and many medical and industrial applications. In 1961, neodymium was incorporated into a glass fiber and found to produce stimulated emission. Shortly thereafter, the ion (Nd 3+ ) was used to dope crystals. Some of the host crystals have included CaF 2 , CaWO 4 , SrWO 4, SrMoO 4, Ca(NbO 3 ) 2, and Y 3 A1 5 O 12 (YAG). The latter crystal is commonly used today largely because of its efficiency. It has good optical quality and high thermal conductivity allowing high repetition rates.
The Nd:YAG laser at 1064 nm has been found to have many tissue effects. It suppresses collagen production in vitro and in vivo, ruptures melanosomes in laboratory animals causing epidermal depigmentation followed by gradual repigmentation and permanent leukotrichia, and it has been extensively used in urology, ophthalmology, neurosurgery, podiatry, dentistry, obstetrics/ gynecology, gastroenterology, plastic surgery, and dermatology for a wide range of applications. Cutaneous targets include vascular lesions, tattoos and permanent cosmetics, deep pigmentation (e.g., nevus of Ota), nevomelanocytes, and hair follicles. An early publication on Nd:YAG laser hair removal was published in 1990. The continuous wave Nd:YAG laser was used to nonselectively destroy hair in urethral grafts. Many other lasers have been used for thermoablation of follicles. Though nonselective destruction is acceptable on unseen mucosal surfaces and small areas, the likelihood of a scar makes this technique unacceptable for large cutaneous surfaces. In order to achieve selective hair removal with this laser, thermal effects can be minimized by shortening the pulse duration. Lasers with this type of pulse-width have been studied by several different investigators.
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PDF Ebook Hair Removal Using An Nd: Yag Laser System
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