For millennia, physicians have endeavored to view the interior of the gastrointestinal tract in order to diagnose and treat disease. Greek, Roman, and Egyptian scholars are all known to have created specula with which body orifices were viewed. Early endoscopes of the nineteenth century were rigid instruments with large lumens that lacked lens systems and depended upon light provided by candle or flame. Later rigid instruments employed lens assemblies and small bulbs at the tip of the instrument which generated intense heat. Early in the twentieth century, instruments with semiflexible rubber tips were developed to facilitate passage of the endoscope into the esophagus. In the mid-twentieth century, the development of fiberoptic technology permitted the evolution of flexible endoscopes that transmitted cold light from an outside source. Light was carried by a fiberoptic bundle from the external source, through the endoscope, to the interior of the viscus being viewed. As light returned through the endoscope, each fiber carried a parcel of the image.
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