درون‌بین

Also known as endoscopes

thumb|Drawing of an endoscope for Fetus|fetal detection, or "fetoscope" An endoscope is an inspection instrument composed of an image sensor, optical lens, a light source and a mechanical device, which is used to look deep into the body by openings such as the mouth or anus. A typical endoscope applies several modern technologies including optics, ergonomics, precision mechanics, electronics, and software engineering. With an endoscope, it is possible to observe lesions that cannot be detected by X-ray, making it useful in medical diagnosis. An endoscope uses tubes only a few millimeters thick