A Brief Description on How Endoscopes Work
An endoscope works by inserting a long, thin and bendable tube into the body. On one end is a light source and in most cases also a video camera. The endoscope can be inserted through a natural opening in the body such as the throat or it can be inserted through a cut made in the skin.
An endoscope consists of two or three optical cables. Each cable includes up to 50,000 separate optical fibers that are made from glass or plastic. One or two of these cables will carry light down into the patient’s body, this illuminates where the endoscope has been inserted. The light is reflected along the walls of the cable into the patient’s body. The light does this due to total internal reflection, which means that for this to happen the light ray must be at an angle of 82 degrees (which is the angle required for air to glass to be internally reflected).
The other cable will carry reflected light that shines off the patient’s body, this light is the image of the body. The light bounces off the glass walls as it goes up to the physician’s eyepiece or into a camera. If the reflected light is carried up to a camera it will then be displayed on a TV monitor.