Electronic endoscope system and method for controlling the same

摘要

A light source device of an electronic endoscope system has first and second semiconductor lasers. In a vascular observation mode, one of the semiconductor lasers is used in a full light state (100% rated output) while the other is used in a reduced light state (for example, 10% rated output). First and second images of an internal body portion are captured with a color imaging device under illumination of two patterns, respectively. Correlation operation of pixel values of three colors is performed between the two images. Noise components, caused by the first or second semiconductor lasers in the light reduced state, are removed from the first and second images. An oxygen saturation level of blood in a blood vessel is calculated using the first and second images with the noise components removed.

主权项

1. An electronic endoscope system comprising:
at least first and second light source systems configured to illuminate an internal body portion including a blood vessel from an insert section to be inserted into a body, the first light source system generating first illumination light including first narrowband light, the second light source system generating second illumination light including second narrowband light, the first light source system having a first semiconductor light source, the second light source system having a second semiconductor light source, wherein a lens through which both the first and second light are transmitted is physically situated in a same organ of interest, and wherein each of the first illumination light and the second illumination light has a different emission spectra; a color imaging device configured to image the internal body portion illuminated with the first or second illumination light, the color imaging device having pixels of two or more colors, electric charge accumulated in each pixel being read out periodically as a pixel value, wherein the color imaging device outputs a first image captured under illumination of the first illumination light, and a second image captured under illumination of the second illumination light; a controller configured to control the first and second light source systems such that the first and second illumination light is applied alternately to the internal body portion in a vascular observation mode, the controller putting the second semiconductor light source of the second light source system into the reduced light state without turning off the second semiconductor light source during the application of the first illumination light and putting the first semiconductor light source of the first light source system into a reduced light state without turning off the first semiconductor light source during the application of the second illumination light; a processor configured to:
calculate and remove a first noise component and a second noise component from the pixel value, used for imaging of vascular information of the internal body portion, with a use of correlation operation of the pixel values of the two or more colors, to calculate a corrected pixel value, the first noise component being a signal component obtained under illumination of the first semiconductor light source in the reduced light state, and the second noise component being a signal component obtained under illumination of the second semiconductor light source in the reduced light state; andproduce a vascular information image based on the corrected pixel value, wherein the vascular information image is produced based on two frames of the first and second images; and a display controller configured to cause the vascular information image to be displayed.