An endoscope is an instrument that allows doctors to view the inner workings of the human body without having to perform surgery. Endoscopes are sometimes called fiberscopes. Endoscopes are primarily used in the health care field, but can also be used for industrial purposes. They make it easier to examine hard-to-reach places such as the inside of fuel tanks and nuclear reactors.
The endoscope is a flexible narrow tube. It contains several bundles of hair-thin glass fibers covered with a reflective coating. An intense light source, usually a halogen lamp, is part of the instrument. The light is transmitted along one bundle of fibers toward the target area and provides enough light to see inside of the human body. Another bundle of fibers carries an image of the target area back up the tube where it is viewed through an eyepiece.
Early Endoscope Research
Crude versions of the endoscope were used as early as the nineteenth century and included long, rigid tubes illuminated by candles. In 1854 Manuel Patricio Rodriguez Garcia, a Spanish-born vocal teacher, designed the forerunner of the laryngoscope that allowed a clear view of the glottis (the vocal cords and the opening between them) and made it possible to see obstructions in the larynx.
The first efforts to develop the kind of glass fibers that would eventually be used in endoscopes were made by the Atomic Energy Authority and by the Rank Organization in Britain. By 1965, a 25-micron (a micron is one-thousandth of a millimeter) fiber had been produced. An American company, Bausch and Lomb, subsequently developed a 15-micron fiber for their Flexiscope which could be used for industrial inspections because it gave off a "cold" light that was safe even in fuel tanks. When the American Cytoscopic Company succeeded in sterilizing glass fibers, the possibilities for medical uses of the endoscope increased greatly.
The modern endoscope can perform an amazing variety of medical procedures. It can do much more than transmit light and a visual image. It also contains water and air channels for flushing water through or inflating targeted areas.
Tiny forceps (tweezers) can be placed at the tip of the endoscope. These can be used to take specimen samples for laboratory analysis and to perform simple operations such as removing colon polyps or gallstones. Endoscopes can also be used to stop hemorrhaging (heavy bleeding) by delivering laser beams directly to the point of bleeding. The blood thickens and the bleeding is stopped.
Different types of endoscopes are specially designed to examine specific parts of the body. Angioscopes pass through the arteries that carry blood to the heart, arthroscopes explore the interiors of joints, bronchoscopes are used with a special dye and fluorescent light to detect lung malignancies (cancers), gastroscopes probe the stomach and upper intestinal tract, and laparoscopes diagnose and treat abdominal conditions.