Endoscope system and operation method therefor

#The present invention relates to an endoscope system and an operation method therefor with which a normal image and a computational image are simultaneously displayed while an uneasy feeling resulting from a delay of the computational image and motion of the photographic subject is relieved.

#In the medical field, it is a common practice to make diagnoses using an endoscope system that includes a light source device, an endoscope, and a processor device. Specifically, in a normal case, white light is used as illumination light to capture an image of an observation target and obtain and display an image (hereinafter referred to as a normal image) with which the observation target can be observed in natural colors. Meanwhile, an endoscope system is widely used that not only captures an image of an observation target as a normal image but also controls the wavelength of illumination light to be radiated onto the observation target and performs signal processing, such as spectral estimation processing, for image signals obtained by image capturing of the observation target, thereby obtaining an observation image in which a specific tissue or structure, such as a blood vessel or a glandular tubular structure, is highlighted.

#Currently, a technique is being studied in which biological function information is measured on the basis of image signals obtained by image capturing of an observation target, and the biological function information is used at the time of diagnosis. For example, it is known that a lesion, such as a cancer, is in a low-oxygen state. Therefore, of the biological function information, the oxygen saturation level is measured and used in a diagnosis to thereby facilitate detection of the lesion.

#FIG. 1 is an external view of an endoscope system;

#FIG. 2 is a block diagram illustrating functions of an endoscope system according to a first embodiment;

#FIG. 3 is a block diagram illustrating functions of a motion detection unit;

#In FIG. 1, an endoscope system 10 has an endoscope 12, a light source device 14, a processor device 16, a monitor 18, and a console 19. The endoscope 12 is optically connected to the light source device 14 and electrically connected to the processor device 16. The endoscope 12 has an insertion part 12a that is inserted in the interior of the body that is an observation target, an operation part 12b that is provided at the proximal end portion of the insertion part 12a, and a bending part 12c and a distal end part 12d that are provided on the distal end side of the insertion part 12a. The bending part 12c makes a bending motion in response to an operation of an angle knob 12e of the operation part 12b. The distal end part 12d is turned in an intended direction in association with the bending motion of the bending part 12c.

#Note that the endoscope system 10 has a plurality of observation modes among which the types of images to be displayed differ. As the observation modes, three types, namely, a normal mode, an oxygen saturation mode, and a multi-observation mode, are provided. In the normal mode, a natural-color normal image obtained by image capturing of an observation target using white light as illumination light is displayed on the monitor 18. In the oxygen saturation mode, an image of oxygen saturation level measurement representing the results of measurement of biological functions is displayed on the monitor 18 on the basis of a first image and a second image in different wavelength ranges. This image is an image (hereinafter referred to as an oxygen saturation image) obtained by measuring the oxygen saturation level of an observation target and representing the measured oxygen saturation level by an image using pseudo colors, etc. by using correlations among the first image, the second image, and oxygen saturation levels. In the multi-observation mode, switching between the normal mode and the oxygen saturation mode is automatically performed. That is, in the multi-observation mode, a normal image in the normal mode and an oxygen saturation image in the oxygen saturation mode are displayed without manually switching between the observation modes. Note that in the multi-observation mode, a blood vessel highlight mode in which a blood vessel highlight image is displayed on the monitor 18 may be performed instead of the oxygen saturation mode. In this case, switching between the normal mode and the blood vessel highlight mode is automatically performed. It is preferable to generate a blood vessel highlight image by performing blood vessel highlight computation between a plurality of images obtained by using multi-frame illumination that is used in the blood vessel highlight mode. Here, mainly, computation between images of a plurality of frames, such as oxygen saturation level computation for measuring an oxygen saturation level and blood vessel highlight computation, is called computational processing. An image generated by performing the computational processing is called a computational image.

#In the endoscope system 10, other observation modes can be used in addition to the multi-observation mode, the normal mode, and the oxygen saturation mode. Switching between the observation modes is performed by a mode switching switch (hereinafter referred to as a mode switching SW) 12f that is a scope switch provided at the operation part 12b of the endoscope. With the mode switching SW 12f, switching between a plurality of types of illumination light can be manually performed. The observation mode assumed in this embodiment is the multi-observation mode.