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Laser light source for spectral dyeing illumination of medic

Time:2020-07-25 23:11 Click:/Second

The invention relates to a medical equipment, in particular to a laser light source used for spectral dyeing and illumination of medical endoscopes. The invention also relates to a laser illumination method for spectral dye illumination of medical endoscopes.
Background technique:
The cold light source for traditional endoscopes is divided into halogen, xenon lamp, LED and other light source driving devices. Among them, the cost of the halogen light source is relatively low, but because the color temperature is low, it can only meet the general endoscope lighting needs, and the color temperature and color rendering index of the xenon light source can be basically Meet the needs of endoscope lighting, but its high cost, high energy consumption and short lifespan also restrict its application on endoscopes. Although the current ordinary LED lighting technology has made great progress, it is still in the color rendering index. It is difficult to meet the needs of high-definition and high-contrast endoscopes.
In recent years, the endoscopic camera technology has made great progress. The image clarity and contrast have been greatly improved. Under ordinary white light, the shape and color of the lesions (such as raised lumps and sunken ulcers) have changed significantly. ) Can be displayed clearly. However, it is difficult to diagnose and even missed diagnosis for small, flat early cancer and dysplasia. In recent years, foreign endoscopy companies have introduced a large number of technologies such as pigment endoscopy, electronic spectroscopy, narrow-band imaging, optical biopsy, and fluorescence imaging, which have greatly improved the diagnosis of early cancer.
Studies have shown that in the visible spectrum, the penetration depth of photons into mucosal tissue is related to the wavelength of the illuminating light source. The shorter the wavelength, the shallower the penetration depth into mucosal tissue. In addition, hemoglobin is the main substance that absorbs visible light and absorbs blue and green light. It has a high rate and basically does not absorb red light.
Other studies have shown that the superficial capillaries on the mucosal surface of the digestive tract have a high absorption rate of blue light at 415nm, while the subcutaneous capillaries have a high absorption rate of green light at 540nm. The wavelength range of the ordinary light source for endoscopes is 400nm-800nm, which has good illumination for ordinary imaging, but it cannot improve the imaging contrast of mucosal capillaries and subcutaneous capillaries. The use of narrowband imaging and electronic dye imaging endoscopy successfully solved the above problems.
The narrow-band illumination imaging technology launched by a Japanese company uses narrow-band interference blue/green filters to produce an illumination system that produces blue/green narrow-band light waves with a center wavelength of 415nm and 540nm and a bandwidth of 30nm.
But this system also has some flaws
1. Gastrointestinal pathology is not completely related to changes in submucosal blood vessels.
For example, some polyps with a tendency to become malignant, theoretically, the changes in the morphology of their surface mucosa are much more obvious than the changes in the blood vessels in the mucosa, and this is not visible to the NBI.
2. Hemoglobin absorbs narrowband waves and changes color.
The principle of NBI is to use the spectral absorption of hemoglobin to highlight colors. When there are some erosions and ulcers in the stomach or colon (this is a very common pathology for gastrointestinal diseases), there are often bleeding spots on the erosion/ulcer surface, and these spots will be too obvious on the NBI. This shortcoming will obscure the findings of other lesions, such as changes in duct openings.
3. NBI can be opened only after the exact location of the lesion is clearly defined, otherwise it will affect the normal gastrointestinal endoscopy.
4. NBI is designed based on a single mode of narrowband wavelength, which means that the results of NBI examination are different in the esophagus and colon.
5. NBI's technical design is to use filters to filter light. If you need to upgrade the technology, you need to upgrade the hardware, which costs a lot.
6. NBI needs to cooperate with the zoom magnifying endoscope to have a good effect.

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