Just as optical fibers have transformed communication, they are also revolutionizingmedicine. These ultra- thin, flexible fibers have opened a window into the living tissues ofthe body. By inserting optical fibers through natural openings or small incisions andthreading them along the body's established pathways, physicians can look into the lungs,intestines, heart and other areas that were formerly inaccessible to them.The basic fiber-optics system is called fiberscope, which consists of two bundles of fibers.One, the illuminating bundle, carries light to the tissues. Is is coupled to a high-intensitylight source. Light enters the cores of the high-purity silicon glass and travels along thefibers. A lens at the end of the bundle collects the light and focuses it into the other bundle,the imaging bundle. Each fiber in the bundle transmits only a tiny fraction of the total image.The reconstructed image can be viewed through an eyepiece or displayed on a televisionscreen. During the last five years, improved methods of fabricating optical fibers have led toa reduction in fiberscope diameter and an increase in the number of fibers, which in turn hasincreased resolution.Optical fibers can also be used to deliver laser light. By use of laser beams, physicians canperform surgery inside the body, sometimes eliminating the need for invasive procedures inwhich healthy tissue must be cut through to reach the site of disease. Many of theseprocedures do not require anesthesia and can be performed in a physician's office. These
techniques have reduced the risk and the cost of medical care.
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