The fiber endoscope system consists of two parts: the endoscope body and the cold light source. There are two optical fiber bundles in the lens body: one is called the light beam, which is used to transmit the light generated by the cold light source to the surface of the object to be observed. The surface of the object to be observed is illuminated; the other is called the image beam, which is to arrange tens of thousands of optical fibers with a diameter of less than 1 micron in a row in a row, one end is aimed at the eyepiece, and the other end is aimed at the observed object through the objective lens On the surface, the doctor can see the surface of the organ very intuitively through the eyepiece, which is convenient for timely and accurate diagnosis of the disease. For example, an endoscopist can look at ulcers or tumors in the stomach and use this to determine the best treatment plan.
Image-conducting fiber bundles form the core of a fiberoptic endoscope. And usually endoscope instruments have two fiberglass tubes through which light enters the body and the doctor observes it through the other tube or through a camera.
With the development of electronics and digital video technology, new electronic endoscopes no longer transmit images with optical fibers, but are replaced by photosensitive integrated circuit camera systems, or CCDs for short. With the help of the necessary optical system and special peripheral drive and signal processing circuit, the CCD chip can convert, store and transmit the scene image point by point, line by line and frame by frame through the CCD area array, and generate a scene image correlation at the output end. The time-series video signal is transmitted to the external circuit through the cable. The conversion processing system undergoes sampling, A/D conversion, digital signal processing, D/A conversion, TV signal encoding, and finally restores the scene image and related text for observation on the monitor. information. Not only the image quality is good, the brightness is strong, but also the image is large, which can detect smaller lesions, and the outer diameter of the electronic endoscope is smaller, the image is clearer and more intuitive, and the operation is convenient.
Some endoscopes even have tiny integrated circuit sensors that feed back what they observe to a computer. It can not only obtain the diagnostic information of the morphology of tissues and organs, but also measure various physiological functions of tissues and organs.
The structure of the electronic endoeye flex is basically the same as that of the fiber endoscope. It can be simply understood that the CCD replaces the image guide beam, and many functions cannot be achieved by the fiber endoscope. The biggest difference between the electronic endoscope and the fiber endoscope is that the CCD device called a miniature image sensor replaces the optical fiber bundle for image transmission.
During the use of the endoscope, the bending part and the insertion tube of the lens body need to continuously perform repeated bending movements. Each component inside the endoscope is then subjected to various stresses such as bending, friction, and extrusion. Bundles are no exception. In terms of the ability to resist external stress, the fatigue strength of cables is much greater than that of optical glass fibers. If other factors affecting the service life of endoscopes are not considered for the time being, the theoretical service life of electronic endoscopes is much longer than that of fiber endoscopes only from the point of view that the optical fiber is easily broken under the action of external force. Another technical problem is the image clarity of the endoscope or the resolution of the endoscope. As far as the current mature technology is concerned, the resolution of the fiber endoscope is far less than that of the electronic endoscope. The resolution depends on the diameter of the optical fiber monofilament, and the space for improving the resolution by reducing the diameter of the optical fiber monofilament is quite small. The products of some manufacturers can be said to be close to the limit, which is only equivalent to the early low-end electronic endoscopy. mirror level.
To sum up, the fiber endoscope has basically reached its technical limit. At present, it has been eliminated by the market without breaking the technical bottleneck, and the use of electronic endoscope has become an objective demand of the market.