Historical Background of Electronic Endoscopy

With the development of incandescent lamps and small cameras, Kussmaul developed a rigid gastroscope in 1865, which can be called the origin of digestive system endoscopy. Since then, flexible gastroscopes have been developed. In 1903, the Germans made the first rectoscope equipped with an electric light source in Europe. This lens-based endoscope is rigid.
Gastric camera developed in Japan in 1950. It can be said that this is the first generation of endoscopes. It is epoch-making in that it can observe the conditions in the stomach that cannot normally be observed by the human eye. However, the pain it causes to the subject is great, and there are still many problems in terms of diagnostic performance.
In 1957, Hirshowit and others applied glass fiber technology to develop the fiberscope, which is the second generation of fiberscope. The emergence of light-guiding fibers allows endoscopes to be made flexible. The light guide fiber is made of synthetic fibers such as glass fiber or plastic, and is a fiber material that uses the principle of multiple total reflection of light to transmit light. In the early 1970s, a variety of microendoscopes with relatively complete performance and convenient use were developed, including stomach, esophagus, duodenum, bronchi, nasopharynx, rectum, colon, small intestine, biliary tract, joints, bladder, etc. Mirror type. The optical fiber through the microendoscope conducts the image and conducts the light source for illumination. Usually the light source is a cold light source, which will not burn or damage internal organs. Because it is soft and pliable, it greatly reduces the pain of the patient. Because of its intuitiveness, it can detect small lesions early, such as cancer, tumor, inflammation, ulcer, polyp, foreign body, etc. It can directly brush exfoliated cells, forceps living tissue for smear or pathological examination. In addition, some treatments can be performed with the help of fiberoptic endoscope, such as sputum suction, high-frequency surgery, hemostasis, clamping stomach worms, drainage stones, foreign body extraction, intracavitary laser treatment, cold therapy, etc. More than 20 years since the development of the looking glass. developed to perfection.
In 1983, Welch-Allyn Company and Japan successively developed the electronic endoscope, namely the third generation endoscope. The third-generation endoscope is based on the wide application of solid-state imaging components and large-scale integrated circuits, and has absorbed the development of CCD, computer, semiconductor technology progress, and the popularization of small cameras and other surrounding scientific and technological progress. It does not use optical fiber to conduct images, but installs a CCD solid-state camera in the head of the endoscope, so that the optical image becomes a TV image, and the TV signal is derived from the wire and displayed on the TV screen. Since no optical fiber is used, the overall diameter and rigidity of the electronic endoscope are greatly reduced. Due to the adoption of CCD imaging technology, the pixel of CCD can reach 40,000 to 100,000, and the signal processing system can observe the lesser curvature of stomach and duodenal villi, and the resolution is greatly improved. The electronic endoscope has no eyepiece, and the image is directly sent to the monitor, or the image is printed out with a video printer. Video recording is also possible.