subject: History And Medical Applications Of Laser [print this page] Albert Einstein theorized the principles and concepts which make Laser possible already in 1917, but it was just in the 60s that Theodor Maiman built the first really functioning laser, which was used, just one year later, to destroy an eye tumor. Since then, every laser manufacturer has been working on the development of more varieties of lasers, well suited to any potential medical application.
Laser is, in itself, simply a very focused and concentrated beam of light, characterized by having a single exact frequency, or wavelength. This specific characteristic is what makes it so useful in medical applications, since different wavelengths of laser, at different energy intensities, act in different ways on the body's tissues, and thus laser can be used as a perfectly sharp scalpel, or to make blood clot instantly, or then again to completely destroy tissues. This variety of effects depends on a very simple fact: our body contains many substances - known as cromophores - which can absorb particular wavelengths of light wholly, without allowing surrounding tissue to incur any harm. Among these substances, as an example, are water, melanin, and haemoglobin. Each cromophore absorbs different wavelengths of light, which to our eyes translate as different visible colors.
Research has by now determined that water easily absorbs light which has a long wavelength, while on the other hand shorter-wavelength light is better absorbed by the chromophore called melanin, found in pigmented areas. That said, it is clear how the matter of obtaining a particular result on the tissues - be it incision, vaporization, or anything else - becomes merely a matter of selecting the most appropriate wavelength of laser light, and applying the correct power as it is projected on the area to be treated.
A common use for shorter-wavelength laser, thus, is heating an undesirable element until it is vaporized, and thus wholly removed: cosmetics have made great use of this effect, by applying it to hair, tattoo and thread veins removal.
We have at our disposal, though, also longer wavelength- lasers, such as erbium lasers, which, as we've outlined a few lines above, behave differently, and are totally absorbed by water, not melanin. This makes them perfectly suited to skin resurfacing treatments, since the energy they bring is captured by deep-seated water cells in the skin. As they shrivel and shrink up under the generated heat, they promote the growth of new, fresh skin cells, improving the texture and state of the patient's skin.
Dermatology is, in fact, one for the areas of medical intervention where laser sees the most effective use. Such applications as the removal of Acne scars, age spots, birthmarks, tattoos,freckles, and superficial lesions, as well as haemangioma, rosacea, excess hair, and veins, and the resurfacing of skin to erase fine lines and wrinkles , have all been made feasible by the medical study of the potential of laser. But that isn't all, not by a long shot; one other medical discipline, Dentistry, makes great use of lasers for cavity preparation, root canal treatments, and teeth whitening, as well as soft tissue surgical procedures and cure of gum diseases, apthae and herpes. And at the same time, in many other medical branches, studies are developing a large range of new techniques - we think we're using only around 20% of the possible applications of laser!
