Research On Multispectral Imaging Technology Of Medical Endoscope

Traditional endoscope can only display normal images of diseased tissue and can detect lesions that change obviously in shape or color.But the pit pattern from lesions and subtle changes in blood vessels at all levels cannot be observed,in addition the flat early neoplasia is hard to diagnose.With the continuous development of endoscopic technology,multispectral imaging has been widely applied in endoscopy.It overcomes the defect of chromoendoscopy,such as cumbersome operation,time-consuming and laborious,and can more clearly show the pattern of blood capillary and the microvascular structure.It was called the "electronic staining technology",because of the same imaging effect as the chromoendoscopy.The research work of this paper mainly focuses on multispectral imaging technology.Firstly,the implementation methods of multispectral imaging technology are introduced,including methods based on narrow band light illumination and methods base on wide spectrum illumination.Among these methods,the principle and the concrete implementation process of Fuji Intelligent Chromo Endoscopy(FICE)are expounded emphatically.Then,three representative groups(12 and 6 groups)were selected from ten wavelength combinations of FICE.By using white light united with narrow band filter,the corresponding wavelength spectral images are obtained and recombined.The image enhancement effect between FICE and narrowband illumination was compared.Next,the target is illuminated with white and blue light,change the spectral intensity ratio of blue and white light,a variety of images is collected,and the difference of images under different intensity ratios is calculated.Finally,identify blood vessels and extract vascular contours,before extraction,all images are normalized,and then the two-dimensional Gaussian matched filter is used to segment the blood vessels,the segmentation results are binarized by otsu algorithm,and the small connected areas of non-blood vessels are eliminated.These results are used as the evaluation basis of blood vessel enhancement effect.Moreover the difference of intensity between white-blue light and white light and the number of blood vessels of white-blue light and blue light are used as the comprehensive evaluation index,the optimum spectral intensity ratio range of blue and white light is determined.When the spectral intensity ratio is between 1.20 and 1.45,the increase of the blue light does not affect the observation effect of the image,and the enhancement effect of the blood vessel get better after using FICE to process the image.