JP6267372B2 - Endoscope system - Google Patents

Description

  The present invention relates to an endoscope system that makes a diagnosis by paying attention to a gland duct structure in a specimen.

  In recent medical treatments, diagnosis and the like using an endoscope system including a light source device, an electronic endoscope, and a processor device are widely performed. For observation in the specimen using an endoscope system, in addition to screening observations that detect possible lesions such as brownish areas and redness from a distant view, detection of such lesions is also possible. When zooming in, a zooming lens is used to enlarge and examine the possible lesion site, and magnified observation is performed. In this enlarged observation, diagnosis is performed by paying attention to the gland duct structure.

  In magnified observation focusing on the duct structure, when a normal light image (image obtained when illuminated with white light) is used, the state of the duct structure is read because the contrast of the duct structure S (Structure) is low. This is difficult (see FIGS. 14A and 14B). Therefore, it is attempted to increase the contrast of the duct structure by distributing a pigment such as indigo and pouring the pigment into the pit portion of the duct structure. Since the duct structure S is clarified by this pigment distribution, the state of the duct structure S can be read (see FIGS. 18A and 18B).

  In addition, blue narrowband light whose wavelength is narrowed in the blue band is illuminated, and the gland duct structure is emphasized white and brightly to display an image. This utilizes the fact that blue narrow-band light is likely to be reflected near the mucosal surface layer. Thus, in the narrow-band blue image obtained by illumination with blue narrow-band light, the contrast of the gland duct structure S is improved, so that the state of the gland duct structure can be read (FIGS. 15A, 15B, and Patent Document 1).

Japanese Patent No. 3607857

  In narrow-band light observation using blue narrow-band light, the structure of the gland duct structure can be emphasized without distributing the dye, so that washing of the dye or the like is unnecessary, and the burden on the doctor is reduced. However, the shape of the gland duct structure displayed by narrowband light observation is displayed in white tone, whereas the shape of the gland duct structure when indigo, one of the pigments is distributed, is displayed in blue tone. For this reason, the gland duct structure is displayed in completely different colors during narrow-band light observation and pigment distribution. If the shape of the duct structure is displayed in a color different from the color of the pigment such as indigo as in this narrow-band light observation, the doctor accustomed to the pigment observation may be confused.

  Therefore, it is required to display the gland duct structure close to the color of a pigment such as indigo even during narrow-band light observation. For example, in Patent Document 1, a narrow-band blue image is assigned to the RGBch of the monitor, and the Bch weighting coefficient is made larger than the Gch and Rch weighting coefficients, thereby displaying the same color as when indigo staining is performed. I try to do it. However, in the case of this Patent Document 1, since not only the gland duct structure but also the fine blood vessels are indigo-stained, the difference between the gland duct structure and the fine blood vessels cannot be emphasized.

  In addition, by performing gradation inversion processing as disclosed in JP 2009-66147 A, JP 4451460 A, JP 3572304 A, and Japanese Patent No. 3559755, a part of the gland duct structure displayed white and bright is darkened. It is possible. By performing the gradation inversion processing in this way, the duct structure can be made to stand out as in the case of indigo distribution. However, since the gradation inversion process is performed on all pixels in the image, not only the gland duct structure but also the gradation of the blood vessel structure is inverted.

  For example, for narrowband light images (images in which both the gland duct structure S and the fine blood vessels V are highlighted by irradiation with blue narrowband light) obtained during narrowband light observation as shown in FIGS. 15A and 15B, When the gradation inversion process is performed, the fine blood vessels V become bright and become noticeable to the same extent as the gland duct structure, as in the narrowband light inversion images of FIGS. 24A and 24B. Thus, if the blood vessel becomes conspicuous, the presence of the blood vessel reduces the visibility of the gland duct structure, so that it is difficult to accurately read the state of the gland duct structure. Therefore, it is required to highlight the gland duct structure without making the blood vessels conspicuous.

  Of the documents describing the gradation inversion process, Japanese Patent No. 3572304 describes that the muscular path of the blood vessel is clarified by the gradation inversion process. There is no mention of clarifying the structure or highlighting the ductal structure without making the blood vessels conspicuous. Also, in other documents, there is no mention of clarifying the duct structure at the time of narrow-band light observation or highlighting the duct structure without conspicuous blood vessels.

  An object of this invention is to provide the endoscope system which can highlight a gland duct structure, without making a blood vessel conspicuous.

The endoscope system of the present invention includes a blue-violet semiconductor light emitting element that emits blue-violet light, a blue semiconductor light-emitting element that emits blue light, and a light source control that individually controls light emission of the blue-violet semiconductor light-emitting element and the blue semiconductor light-emitting element. A normal light image processing unit that performs processing for obtaining a normal light image on an image obtained by imaging a specimen illuminated with light including blue light, and illumination with light including blue-violet light and blue light A first special light image processing unit that performs processing for obtaining a first special light image on an image obtained by imaging the obtained sample, and a sample illuminated by light including blue-violet light and blue light A second special light image processing unit that performs processing for obtaining a second special light image different from the first special light image, a normal observation mode for performing processing for obtaining a normal light image, and blue-violet light The emission ratio is larger than that in the normal observation mode and the first characteristic A mode switching unit that switches between a first special observation mode for performing a process for obtaining a light image and a second special observation mode for performing a process for obtaining a second special light image in which the emission ratio of blue-violet light is larger than that in the normal observation mode. The second special light image is an endoscope system in which the gland duct structure is clarified and the fine blood vessels are suppressed .
In addition, another endoscope system of the present invention includes a blue-violet semiconductor light-emitting element that emits blue-violet light, a blue semiconductor light-emitting element that emits blue light, and light emission of the blue-violet semiconductor light-emitting element and the blue semiconductor light-emitting element individually. A light source control unit for controlling, a normal light image processing unit for performing processing for obtaining a normal light image on an image obtained by imaging a specimen illuminated with light including blue light, and blue-violet light and blue light. A first special light image processing unit that performs processing for obtaining a first special light image on an image obtained by imaging a specimen illuminated with the light including light, and illuminated with light including blue-violet light and blue light A second special light image processing unit that performs a process of obtaining a second special light image different from the first special light image, and a normal observation mode that performs a process of obtaining a normal light image, on an image obtained by imaging the specimen; , The emission ratio of blue-violet light is larger than the normal observation mode, A first special observation mode for performing processing for obtaining a first special light image, and a second special observation mode for performing processing for obtaining a second special light image in which the emission ratio of blue-violet light is larger than that in the normal observation mode. A mode switching unit for switching, and the second special light image includes a suppression process for suppressing display of microvessels and an image of gland duct structures for an image including gland duct structures and microvessels darker than the gland duct structures. It is obtained by applying a gradation inversion process that darkens the microvessel.

The second special light image is preferably close to an image obtained when a blue pigment is dispersed . In the first special light image, it is preferable that a gland duct structure and a fine blood vessel are highlighted.

Passing ordinary image processing unit, the image obtained by imaging the illuminated specimen with light including blue-violet light and blue light, it is preferable to perform the process of obtaining the normal light image. The normal light image preferably has a color tone equivalent to that of an image obtained when white light is illuminated. In the normal observation mode, it is preferable that the emission ratio of light including blue light is appropriately set according to the scope type.

In the first image, the duct structure is brighter than the mucous membrane and the fine blood vessels are darker than the mucous membrane. The suppression / reversal processing unit includes a suppression unit that performs suppression processing on the first image, and a suppression process. A first gradation inversion unit that performs gradation inversion processing for darkening the gland duct structure from the mucous membrane,
It is preferable to provide. The first image is composed of RGB image data, and the first gradation inversion unit preferably inverts the gradation of the RGB image data subjected to the suppression process. A separation unit that separates the first image that has been subjected to the suppression process into brightness data having brightness information and color data having color information; Inversion is preferred.

  In the first image, the duct structure is brighter than the mucous membrane and the fine blood vessels are darker than the mucous membrane. The suppression / reversal processing unit includes a suppression unit that performs suppression processing on the first image, and a suppression process. A second gradation inversion unit that performs gradation inversion processing that darkens the gland duct structure from the mucous membrane and makes the color of the gland duct structure close to the color of the blue pigment for the first image Is preferred. The tone reversal processing of the second tone reversal unit preferably brings the mucous membrane color closer to the mucous membrane color when illuminated with white light.

  The first image is composed of RGB image data, and the second gradation inversion unit performs B inversion of the gradation processing so that the intermediate value becomes brighter for the R image data subjected to the suppression processing, and the suppression processing is performed. Is preferably reversed so that the intermediate value becomes dark, and so that the dark portion after gradation is brightened. A separation unit that separates the first image subjected to the suppression process into brightness data having brightness information and color data having color information, and the second gradation inversion unit has an intermediate value for the brightness data. It is preferable to perform gradation processing that inverts the gradation so that it becomes brighter and brings the color near yellow closer to blue for the color data. The blue dye is preferably indigo.

  The first image preferably has a blue narrow-band image including the first and fine blood vessels. It is preferable that the first and the fine blood vessel are provided with a magnifying means for magnifying the first blood vessel and the first image is obtained at the time of magnifying observation using the magnifying means. The gland duct structure is a gland duct structure, and the microvessel is preferably a microvessel.

  According to the present invention, the gland duct structure can be highlighted without making blood vessels conspicuous.

It is an external view of an endoscope system. It is a block diagram which shows each structure of the endoscope system of 1st Embodiment. It is a graph which shows the emission spectrum of white light. It is a graph which shows the emission spectrum of special light. It is a block diagram which shows each structure of a blood-vessel suppression part. It is a graph which shows the luminance distribution in the predetermined line of B image signal. It is a graph which shows the luminance distribution in the predetermined line of the blood vessel extraction image. It is a graph which shows the input-output relationship of LUT in the image generation part for blood vessel suppression. It is a graph which shows the luminance distribution in the predetermined line of the image for blood vessel suppression. It is a graph which shows the luminance distribution in the predetermined line of the blood vessel suppression image obtained by combining the image for blood vessel suppression with the base image. It is a graph which shows the tone curve for RGB image data used for the gradation inversion of 1st Embodiment. It is explanatory drawing for demonstrating a gradation inversion process. It is a block diagram of the gradation inversion part which has a Lab conversion part and a RGB conversion part. It is a graph which shows the tone curve for Lab data used for the gradation inversion process of 1st Embodiment. It is a flowchart showing a series of flows in the first embodiment. It is an image figure of the normal light image obtained at the time of expansion observation. It is the image figure of FIG. 14A which showed the duct structure by the black thick line part. It is an image figure of the 1st special light image (narrow-band light image) obtained at the time of expansion observation. It is the image figure of FIG. 15A which showed the duct structure by the black thick line part. It is an image figure of the blood vessel suppression image obtained at the time of expansion observation. It is an image figure of FIG. 16A which showed the duct structure by the black thick line part. It is an image figure of the blood vessel suppression and inversion image obtained at the time of magnified observation. It is the image figure of FIG. 17A which showed the duct structure by the black thick line part. It is an image figure of the pigment distribution image obtained at the time of magnified observation. It is an image figure of FIG. 18A which showed the duct structure by the black thick line part. It is a graph which shows the tone curve for RGB image data used for the gradation inversion of 2nd Embodiment. It is a graph which shows the tone curve for Lab data used for the gradation inversion process of 2nd Embodiment. It is a block diagram which shows each structure in the endoscope system of a frame sequential system. It is a top view of a rotation filter. It is a block diagram of the 2nd special light image processing part which has a spectrum operation part. It is an image figure of the narrow-band light inversion image obtained at the time of expansion observation. It is the image figure of FIG. 24A which showed the duct structure by the black thick line part.

[First Embodiment]
As shown in FIG. 1, the endoscope system 10 according to the first embodiment includes an endoscope 12, a light source device 14, a processor device 16, a monitor 18, and a console 20. 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 portion 21 to be inserted into a specimen, an operation portion 22 provided at a proximal end portion of the insertion portion, a bending portion 23 and a distal end portion 24 provided on the distal end side of the insertion portion 21. doing. By operating the angle knob 22a of the operation unit 22, the bending unit 23 performs a bending operation. With this bending operation, the tip 24 is directed in a desired direction.

  In addition to the angle knob 22a, the operation unit 22 is provided with a mode switching SW 22b and a zoom operation unit 22c. The mode switching SW 22b is used for switching operation between three types of modes: a normal observation mode, a first special observation mode, and a second special observation mode. The normal observation mode is an observation mode that uses white light. The first and second special observation modes are observation modes that use bluish special light. In the first special observation mode, both the gland duct structure and microvessels are clarified, and in the second special observation mode, blood vessels are suppressed. And clarify the duct structure. The zoom operation unit 22c is used for a zoom operation for driving the zooming lens 47 (see FIG. 2) in the endoscope 12 to enlarge the specimen.

  The processor device 16 is electrically connected to the monitor 18 and the console 20. The monitor 18 outputs and displays image information and the like. The console 20 functions as a UI (user interface) that receives input operations such as function settings. The processor device 16 may be connected to an external recording unit (not shown) for recording image information and the like.

  As shown in FIG. 2, the light source device 14 includes a blue laser light source (445LD) 34 that emits blue laser light having a central wavelength of 445 nm and a blue-violet laser light source (405LD) 36 that emits blue-violet laser light having a central wavelength of 405 nm. It is provided as a light source. Light emission from the semiconductor light emitting elements of the light sources 34 and 36 is individually controlled by the light source control unit 40, and the light quantity ratio between the emitted light of the blue laser light source 34 and the emitted light of the blue-violet laser light source 36 is freely changeable. It has become. In the normal observation mode, the light source control unit 40 mainly controls the blue laser light source 34 to control to emit blue violet laser light slightly. On the other hand, in the first and second special observation modes, both the blue laser light source 34 and the blue-violet laser light 36 are driven, and the emission ratio of the blue-violet laser light is determined from the emission ratio of the blue laser light. Is also controlled to be larger.

  Note that the full width at half maximum of the blue laser beam or the blue-violet laser beam is preferably about ± 10 nm. In the normal observation mode, the driving of the blue-violet laser beam 36 may be stopped. As the blue laser light source 34 and the blue-violet laser light source 36, a broad area type InGaN laser diode can be used, and an InGaNAs laser diode or a GaNAs laser diode can also be used. In addition, a light-emitting body such as a light-emitting diode may be used as the light source.

  Laser light emitted from each of the light sources 34 and 36 enters a light guide (LG) 41 through optical members (all not shown) such as a condenser lens, an optical fiber, and a multiplexer. The light guide 41 is built in a universal cord (not shown) that connects the light source device 14 and the endoscope 12. A blue laser beam having a central wavelength of 445 nm or a blue-violet laser having a central wavelength of 405 nm is propagated to the distal end portion 24 of the endoscope 12 through the light guide 41. A multimode fiber can be used as the light guide 41. As an example, a thin fiber cable having a core diameter of 105 μm, a cladding diameter of 125 μm, and a diameter including a protective layer serving as an outer shell of φ0.3 to 0.5 mm can be used.

  The distal end portion 24 of the endoscope has an illumination optical system 24a and an imaging optical system 24b. The illumination optical system 24 a is provided with a phosphor 44 on which blue laser light having a central wavelength of 445 nm or a blue-violet laser having a central wavelength of 405 nm from the light guide 41 is incident, and an illumination lens 45. Fluorescence is emitted from the phosphor 44 by irradiating the phosphor 44 with blue laser light. Some of the blue laser light passes through the phosphor 44 as it is. The blue-violet laser light is transmitted without exciting the phosphor 44. The light emitted from the phosphor 44 is irradiated into the specimen through the illumination lens 45.

  Here, in the normal observation mode, since the blue laser light is mainly incident on the phosphor 44, as shown in FIG. 3A, the blue laser light and the fluorescence excited and emitted from the phosphor 44 by the blue laser light are combined. The white light is irradiated into the specimen. On the other hand, in the first and second special observation modes, since both the blue-violet laser beam and the blue laser beam are incident on the phosphor 44, as shown in FIG. 3B, the blue-violet laser beam, the blue laser beam, and the blue laser beam Special light obtained by combining fluorescence excited and emitted from the phosphor 44 by the laser light is irradiated into the specimen. In the first and second special observation modes, since the emission ratio of the blue-violet laser light is larger than the emission ratio of the blue laser light, the special light contains a large amount of blue components and the wavelength range is almost the entire visible light range. It is a light that extends to

The phosphor 44 absorbs a part of the blue laser light and emits green to yellow excitation light (for example, a YAG phosphor or a phosphor such as BAM (BaMgAl ₁₀ O ₁₇ )). It is preferable to use what is comprised including. If a semiconductor light emitting device is used as an excitation light source for the phosphor 44 as in this configuration example, high intensity white light can be obtained with high luminous efficiency, and the intensity of white light can be easily adjusted, and the color of white light can be easily adjusted. Changes in temperature and chromaticity can be kept small.

  As shown in FIG. 2, the imaging optical system 24 b of the endoscope 12 includes an imaging lens 46, a zooming lens 47, and a sensor 48. Reflected light from the specimen enters the sensor 48 via the imaging lens 46 and zooming lens 47. Thereby, a reflected image of the specimen is formed on the sensor 48. The zooming lens 47 moves between the tele end and the wide end by operating the zoom operation unit 22c. When the zooming lens 47 moves to the wide end side, the reflected image of the specimen is enlarged, while when the zooming lens 47 moves to the tele end side, the reflected image of the specimen is reduced.

  The sensor 48 is a color image sensor, picks up a reflected image of the specimen, and outputs an image signal. The sensor 48 is preferably a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, or the like. The image sensor used in the present invention is a color image sensor for obtaining image signals of three colors of R (red), G (green), and B (blue), and a so-called RGB image sensor provided with an RGB filter on the imaging surface. Alternatively, a so-called complementary color image sensor having complementary color filters of C (cyan), M (magenta), Y (yellow), and G (green) on the imaging surface may be used. In the case of a complementary color image sensor, RGB three-color image signals can be obtained by color conversion from four CMYG image signals. In this case, any one of the endoscope 12, the light source device 14, and the processor device 16 needs to include color conversion means for performing color conversion from the CMYG four-color image signal to the RGB three-color image signal. is there.

  The image signal output from the sensor 48 is transmitted to the CDS / AGC circuit 50. The CDS / AGC circuit 50 performs correlated double sampling (CDS) and automatic gain control (AGC) on an image signal which is an analog signal. The image signal that has passed through the CDS / AGC circuit 50 is converted into a digital image signal by an A / D converter (A / D converter) 52. The A / D converted digital image signal is input to the processor device 16.

  The processor device 16 includes a receiving unit 54, an image processing switching unit 60, a normal light image processing unit 62, a first special light image processing unit 64, a second special light image processing unit 65, and an image display signal generation unit 66. And. The receiving unit 54 receives a digital image signal from the endoscope 12. The receiving unit 54 includes a DSP (Digital Signal Processor) 56 and a noise removing unit 58. The DSP 56 performs gamma correction and color correction processing on the digital image signal. The noise removing unit 58 removes noise from the digital image signal by performing noise removal processing (for example, a moving average method, a median filter method, etc.) on the digital image signal subjected to gamma correction or the like by the DSP 56. The digital image signal from which noise has been removed is transmitted to the image processing switching unit 60.

  The image processing switching unit 60 transmits a digital image signal to the normal light image processing unit 62 when the normal observation mode is set by the mode switching SW 22b. On the other hand, when the first special observation mode is set, the digital image signal is transmitted to the first special light image processing unit 64, and when the second special observation mode is set, the digital image signal is transmitted. Transmit to the second special light image processing unit 65.

  The normal light image processing unit 62 includes a color conversion unit 68, a color enhancement unit 70, and a structure enhancement unit 72. The color conversion unit 68 assigns the input RGB 3-channel digital image signals to R image data, G image data, and B image data, respectively. These RGB image data are further subjected to color conversion processing such as 3 × 3 matrix processing, gradation conversion processing, and three-dimensional LUT processing, and converted to color-converted RGB image data.

  The color enhancement unit 70 performs various color enhancement processes on the color-converted RGB image data. The structure enhancement unit 72 performs structure enhancement processing such as sharpness and contour enhancement on the color enhancement processed RGB image data. The RGB image data subjected to the structure enhancement process by the structure enhancement unit 72 is input to the image display signal generation unit 66 as a normal light image.

  The first special light image processing unit 64 includes a color conversion unit 74, a color enhancement unit 76, and a structure enhancement unit 77. The color conversion unit 74 assigns the G image signal to the R image data and assigns the B image signal to the G image data and the B image data among the RGB three-channel digital image signals. Here, although the B image signal is assigned to the B image data, the B image signal is assigned to the G image data instead of the G image signal. The R image data is not the R image signal but the G image signal. Therefore, the image displayed on the monitor 18 based on the BGR image data is a pseudo color image. In the color conversion unit 74, as in the color conversion unit 68, RGB image signals may be assigned to RGB image data to generate a white-based image.

  As with the color enhancement unit 70, the color enhancement unit 76 performs various color enhancement processes on the color-converted RGB image data. Similar to the structure emphasizing unit 72, the structure emphasizing unit 77 performs structure emphasizing processing such as sharpness and contour emphasis on the color-enhanced RGB image data. The RGB image data subjected to the structure enhancement process by the structure enhancement unit 77 is input to the image display signal generation unit 66 as a first special light image.

  The second special light image processing unit 65 performs a blood vessel suppression process for suppressing blood vessel display on the input RGB3 channel digital image signal, and generates a blood vessel suppression image, and a blood vessel suppression A gradation inversion unit 79 that performs gradation inversion processing for inverting the gradation of the image and generates a blood vessel suppression / inversion image that emphasizes the display of the gland duct structure while suppressing the display of blood vessels.

  As shown in FIG. 4, the blood vessel suppression unit 78 includes a base image generation unit 80, a frequency filtering processing unit 81, a blood vessel suppression image generation unit 82, and an image synthesis unit 83. Similar to the color conversion unit 74, the base image generation unit 80 allocates the G image signal to the R image data and the B image signal to the G image data and the B image data among the RGB three-channel digital image signals. These RGB image data become a base image. Since this base image is the first special light image, it is displayed in a pseudo color on the monitor 18. The base image generation unit may generate a white base image that is not a pseudo color by allocating RGB image signals to RGB image data, as in the color conversion unit 68.

  The B image data of this base image has many reflection components in the blue band such as blue-violet laser light and blue laser light that can give a structure enhancement effect to the gland duct structure and fine blood vessels. Therefore, as shown in FIG. 5, in the B image data 84 of the base image, the duct structure S (Structure) is more than the mucous membrane M (Mucous membrane) due to light of blue components such as blue-violet laser light and blue laser light. It is displayed brightly. This is because the blue component light is likely to be reflected near the surface of the mucosa where the glandular duct structure S is present. In addition, blue-violet laser light and blue laser light are highly linear light, unlike blue narrow-band light obtained by wavelength-separating broadband light such as xenon light. Reach deep. By this effect, the duct structure S is displayed brighter. On the other hand, the fine blood vessel V (Vascular) is darker than the mucous membrane M because it absorbs well blue light having a high hemoglobin absorption coefficient such as blue-violet laser light and blue laser light among special light.

  The frequency filtering processing unit 81 performs a frequency filtering process for extracting a frequency band component corresponding to a fine blood vessel on the mucosal surface layer of the B image signal among the RGB 3 channel digital image signals to generate a blood vessel extraction image signal. To do. As shown in FIG. 6, in the blood vessel extraction image signal 85, the pixel of the fine blood vessel V included in the extraction band component of the frequency filtering process has a down edge whose output value is “negative”. On the other hand, the output value of the duct structure S not included in the extraction band component of the frequency filtering process is almost “0”. In addition, since the mucosa M (Mucous membrane) has almost no change in luminance value, the output value is almost “0”. When emphasizing the duct structure, the extraction band component includes the frequency band of the duct structure so that the duct structure is extracted together with the fine blood vessels. The blood vessel extraction image signal in this case also includes pixels of the up-edge gland duct structure whose output value is “positive”.

  The blood vessel suppression image generation unit 82 generates a blood vessel suppression image used for display suppression of the fine blood vessels from the blood vessel extraction image signal. The blood vessel suppression image generation unit 82 includes an LUT 82a that inputs a blood vessel extraction image signal and outputs a blood vessel suppression image. As shown in the input / output relationship of FIG. 7, the LUT 82a outputs a positive value with respect to an input of a negative value in the blood vessel extraction image signal. As a result, as shown in FIG. 8, a blood vessel suppression image in which the pixel of the fine blood vessel V is “positive” is obtained. By adding this blood vessel suppression image to the base image, the brightness of the fine blood vessels approaches the mucous membrane, and the contrast between the mucous membrane and the fine blood vessels is reduced or almost no difference therebetween.

  In the LUT 82a, as shown in the input / output relationship of FIG. 7, “0” is output in response to an input of a positive value (up edge) in the blood vessel extraction image signal. However, when the gland duct structure is emphasized. May output a “positive” value. At this time, it is preferable to increase the “positive” value to be output in accordance with the degree of enhancement. Further, the input / output relationship of FIG. 7 can be adjusted as appropriate by the console 20 or the like. At this time, it is preferable to adjust so that the pixel values of the fine blood vessel pixel and the mucous membrane pixel are substantially the same when the blood vessel suppression image is added to the base image.

  The image composition unit 83 composes a blood vessel suppression image with a base image to create a blood vessel suppression image in which the display of fine blood vessels is suppressed. In this image composition unit 83, the value of each pixel of the blood vessel suppression image is added to each pixel (Bch) of the B image data in the base image, but for each pixel of the G image data or R image data. Alternatively, the value of each pixel of the enhanced / suppressed image may be added. Note that it is preferable to suppress the microvessel to an extent that the microvessel cannot be distinguished from the mucous membrane by combining the blood vessel suppression image and the base image (that is, to eliminate the microvessel).

  For example, as shown in FIG. 9, when the blood vessel suppression image 100 (see FIG. 8) is synthesized with Bch (each pixel of B image data) of the base image 105, the contrast between the fine blood vessel V and the surrounding mucous membrane M Decreases, and a blood vessel suppression image 110 in which the display of the fine blood vessels V is suppressed is obtained (a dotted line indicates a luminance value before synthesis).

  The gradation inversion unit 79 performs gradation inversion processing on the RGB image data of the blood vessel suppression image. In the gradation inversion unit 79, the RGB image of the blood vessel suppression / inversion image in which the gradation is inverted according to the tone curves 125a to 125c for the RGB image data shown in FIG. 10 in response to the input of the RGB image data of the blood vessel suppression image. Output data. As a result, the intermediate value portion maintains the same brightness, while the bright portion becomes dark and the dark portion becomes bright. The output RGB image data of the blood vessel suppression / inverted image is transmitted to the image display signal generation unit 66 as a second special light image. Note that data relating to the tone curves 125 a to 125 c is stored in the LUT 79 a in the gradation inversion unit 79.

  For example, when the gradation inversion process is performed on the B image data of the blood vessel suppression image 110 (see FIG. 9), B image data of the blood vessel suppression / inversion image 112 as shown in FIG. 11 is obtained. In the B image data of the blood vessel suppression / reverse image 112, the gland duct structure S is darker than the mucous membrane M. By expressing the duct structure S in a darker color than the mucous membrane M in this way, the duct structure S can be made to stand out like indigo distribution. On the other hand, since the fine blood vessel V is originally close to the brightness of the mucous membrane, even if the gradation inversion process is performed, the fine blood vessel V after the gradation inversion is slightly brighter than the mucous membrane M. Almost the same as brightness. Therefore, the blood vessel suppression / inverted image 112 is an image in which the presence of blood vessels does not hinder the visibility of the gland duct structure, and a doctor accustomed to pigment observation can read the state of the gland duct structure without feeling uncomfortable. It has become.

  Note that the gradation inversion unit 79 separates the RGB image data of the blood vessel suppression image into brightness data and color data instead of performing the gradation inversion processing on the RGB image data of the blood vessel suppression image. Only the gradation inversion process may be performed. After the gradation inversion, the RGB data of the blood vessel suppression / inversion image is generated by performing RGB conversion on the brightness data and the color data after the gradation inversion process.

  For example, when the RGB image data of the blood vessel suppression image is subjected to Lab conversion, as shown in FIG. 12A, the gradation inversion unit 79 is provided with a Lab conversion unit 79b and an RGB conversion unit 79c. First, in the Lab conversion unit 79b, RGB image data of the blood vessel suppression image is subjected to Lab conversion to have L data having brightness information, a data having color information about red to green, and color information about blue to yellow. b. Then, as shown in FIG. 12B, the L data is subjected to the process of inverting the gradation according to the tone curve 127a, while the a data and the b data are maintained according to the tone curves 127b and 127c. Perform the process. Thereby, the gland duct structure S can be brought closer to an indigo color darker than the mucous membrane without changing the color tone.

  The L data, a data, and b data are subjected to RGB conversion by the RGB conversion unit 79c to be converted into RGB image data of a blood vessel suppression / inverted image. The brightness data and the color data may be separated by YCbCr conversion in addition to Lab conversion. Further, data relating to the tone curves 127 a to 127 c are stored in the LUT 79 a in the gradation inversion unit 79.

  The image display signal generation unit 66 includes a normal light image, a first special light image, and a second special light input from the normal light image processing unit 62, the first special light image processing unit 64, and the second special light image processing unit 65. The image is converted into a display image signal for display as a displayable image on the monitor 18. Based on the display image signal after conversion, the monitor 18 displays the normal light image, the first special light image, and the second special light image.

  Next, a series of flows in the present embodiment will be described along the flowchart of FIG. First, screening is performed from a distant view state in the normal observation mode. At the time of this screening, when a portion (possible lesion) such as a brownish area or redness is detected, the zoom operation unit 22c is operated to perform enlargement observation for enlarging the lesion potential portion. At the time of this magnified observation, a normal light image in which the fine structure S is magnified as shown in FIGS. 14A and 14B is displayed on the monitor 18. When the state of the gland duct structure can be accurately read from the normal light image, it is determined whether or not the possible lesion site is a lesion or a non-lesion based on the normal light image.

  However, as can be seen by comparing FIG. 14A and FIG. 14B, it is generally difficult to accurately read the state of the duct structure S from the normal light image because the contrast of the duct structure S is low. Therefore, in most cases, the mode is switched to the first special observation mode by operating the mode switching SW 22b. As a result, the first special light image in which the gland duct structure S and the fine blood vessels V are highlighted as shown in FIGS. 15A and 15B is displayed on the monitor 18.

  If the doctor can accurately read the state of the duct structure from the first special light image, based on the first special light image, the doctor determines whether the possible lesion site is a lesion or a non-lesion. Make a decision. Since this first special light image highlights the duct structure S, it is useful for reading the state of the duct structure S as compared with the normal light images of FIGS. 14A and 14B. However, the first special light image highlights not only the gland duct structure S but also the fine blood vessels V. For this reason, when the gland duct structure S is partially extinguished, the presence of the fine blood vessels V may interfere with the visibility of the gland duct structure. In this case, the state of the duct structure may not be accurately read.

  In such a case, the mode switching SW 22b is operated to switch to the second special observation mode. In the second special observation mode, first, processing for suppressing display of blood vessels is performed by the blood vessel suppression unit 78 on the RGB image signal obtained by imaging in the specimen. Thereby, a blood vessel suppression image in which the display of the fine blood vessels V is suppressed as shown in FIGS. 16A and 16B is obtained. Compared with the first special light images of FIGS. 15A and 15B, this blood vessel suppression image does not hinder the visibility of the gland duct structure S, and thus the state of the gland duct structure S can be easily read. .

  Further, the gradation reversing unit 79 performs gradation reversal processing on the blood vessel suppression image, thereby suppressing the display of the fine blood vessels V as shown in FIGS. A blood vessel suppression / inversion image that is darkened to improve contrast is obtained. This blood vessel suppressed / inverted image is displayed on the monitor 18 as a second special light image. In the second special light image, the presence of the microvessel V does not hinder the visibility of the gland duct structure S due to the display suppression of the microvessel V, and the gland duct structure S is dark, so the color of the second special light image is indigo. It is approaching. Therefore, this second special light image is almost the same as the image obtained when indigo is distributed, so that doctors accustomed to pigment observation can accurately read the duct structure without being confused. Will be able to.

  When the doctor can accurately read the state of the duct structure from the second special light image, the doctor determines whether or not the possible lesion site is a lesion or a non-lesion based on the second special light image. Make a decision. On the other hand, when the state of the duct structure cannot be accurately read from the second special light image, a pigment such as indigo is distributed as a final means. This pigment distribution causes the pigment to flow into the pit portion of the gland duct structure. As a result, as shown in FIGS. 18A and 18B, a pigment distribution image in which the gland duct structure S is highlighted is displayed on the monitor 18.

  Then, the doctor reads the state of the gland duct structure S based on the pigment distribution image displayed on the monitor 18 and determines whether or not the likely lesion site is a lesion or a non-lesion. In addition, after the observation of the dye distribution image, it is necessary to wash the distributed dye. For this reason, the observation with the dye distribution image is the final means performed when the second special light image cannot be read.

[Second Embodiment]
In the first embodiment, the gland duct structure is highlighted as in the case of indigo distribution by gradation reversal processing. In the second embodiment, in addition to this, when the color of the mucous membrane is imaged with white light, A process for bringing the color of the gland duct structure closer to the color of indigo is performed while making the color closer. In the second embodiment, in response to the input of RGB image data of a blood vessel suppression image, the RGB image data of the blood vessel suppression / inversion image in which the gradation is inverted according to the tone curves 180a to 180c for RGB image data shown in FIG. Is output.

  Since the tone curve 180a for R image data has a convex shape, the intermediate value of the input R image data is slightly increased and output. On the other hand, the tone curve 180c for B image data has a concave shape, so that the intermediate value of the input B image data is slightly reduced and output. Since the tone curve 180b for G image data is linear, the balance of intermediate values before and after input / output is substantially maintained. Therefore, in the blood vessel suppression / inverted image obtained by synthesizing the RGB image data after gradation inversion, the color of the mucous membrane, which occupies most of the intermediate values, becomes reddish. The color of the reddish mucous membrane on this blood vessel suppression / reversal image is almost the same as the color when imaged with white light.

  The tone curve 180c for B image data indicates the brightness of the shadow portion when the highlight portion (that is, the portion of the gland duct structure S) of the input B image data is output as a shadow portion by gradation inversion. Is defined to be slightly brighter. In this way, by slightly brightening the shadow portion of the B image (that is, the portion of the duct structure S), the color of the duct structure becomes bluish in the blood vessel suppression / inverted image. Thereby, the color of the gland duct structure comes close to the color of indigo.

  Note that tone curves 182a to 182c shown in FIG. 20 are used when the RGB image data of the blood vessel suppression image is subjected to Lab conversion and gradation inversion is performed. Since the tone curve 182a for L data has a convex shape, the intermediate value of the input L data is output with a slight increase. On the other hand, since the tone curve 182b for a data and the tone curve 182c for b data are linear, the balance of intermediate values before and after input / output is maintained. The tone curve 182c for b data is defined so that the color near yellow in the input b data approaches blue. Therefore, in the blood vessel suppression / inversion image after RGB conversion of L data, a data, and b data, the mucosa occupying the intermediate value approaches the color when imaged with white light, and the color of the gland duct structure is the color of indigo Get closer to.

  In the first and second embodiments, the present invention is implemented by a simultaneous method in which a plurality of image signals necessary for each observation mode are simultaneously acquired by a color sensor. However, instead of this, it is necessary for each observation mode. Even in the case of a frame sequential type in which a plurality of image signals are sequentially acquired by a monochrome sensor, the present invention can be similarly implemented.

  As shown in FIG. 21, the light source device 14 of the field sequential endoscope system 200 includes a broadband light source 202, a rotary filter 204, a blue laser light source 34, a blue-violet laser light source 36, and a light source control unit 40. A filter switching unit 205 is provided. Further, the phosphor 44 is not provided in the illumination optical system 24a of the endoscope 12. Further, the imaging optical system 24b is provided with a monochrome sensor 206 in which a color filter is not provided, instead of the color sensor 48. Other than that, it is the same as the endoscope system 10 of the first embodiment.

  The broadband light source 22 is a xenon lamp, a white LED, or the like, and emits white light having a wavelength range from blue to red. The rotary filter 204 includes a normal observation mode filter 208 provided on the inner side and first and second special observation mode filters 209 provided on the outer side (see FIG. 22). The filter switching unit 205 moves the rotary filter 204 in the radial direction. When the mode switching SW 22b sets the normal observation mode, the filter switching unit 205 inserts the normal observation mode filter 208 of the rotary filter 204 into the white light path. When the first and second special observation modes are set, the special observation mode filter 209 of the rotation filter 204 is inserted into the white light path.

  As shown in FIG. 22, the normal observation mode filter 208 includes a B filter 208 a that transmits blue light of white light, a G filter 208 b that transmits green light of white light, and white light along the circumferential direction. Among them, an R filter 20c that transmits red light is provided. Therefore, in the normal observation mode, the rotating filter 204 rotates, and blue light, green light, and red light are alternately irradiated into the specimen.

  The first and second special observation mode filters 209 include a Bn filter 209a that transmits blue narrow-band light having a center wavelength of 415 nm among white light and a green narrow light having a center wavelength of 540 nm among white light along the circumferential direction. A Gn filter 209b that transmits band light is provided. Therefore, in the special observation mode, the rotating filter 204 is rotated so that blue narrow band light and green narrow band light are alternately irradiated into the specimen.

  In the field sequential endoscope system 200, in the normal observation mode, the monochrome sensor 206 captures an image of the inside of the specimen every time blue light, green light, and red light are irradiated into the specimen. Thereby, RGB image signals of three colors are obtained. Based on the RGB image signals, a normal light image is generated by the same method as in the first embodiment.

  On the other hand, in the first and second special observation modes, the monochrome sensor 206 images the inside of the specimen every time the narrow blue band light and the green narrow band light are irradiated into the specimen. Thereby, a Bn image signal and a Gn image signal are obtained. Based on the Bn image signal and the Gn image signal, the first and second special light images are generated. When generating the first special light image, unlike the first and second embodiments, the Bn image signal is assigned to the B image data and the G image data, and the Gn image signal is assigned to the R image data. A first special light image is generated. The rest is the same as in the first and second embodiments.

  Further, when generating the second special light image, unlike the first and second embodiments, by assigning a Bn image signal to B image data and G image data, and assigning a Gn image signal to R image data, Generate a base image. In addition, a Bn image signal is used instead of the B image signal for generating the blood vessel suppression image. Other than that, the second special light image is generated by the same method as in the first and second embodiments.

  In the above embodiment, the blood vessel suppression image in which the display of blood vessels is suppressed is subjected to gradation inversion processing to generate a blood vessel suppression / inversion image. Then, a blood vessel suppression / inverted image may be generated by performing processing for suppressing the display of blood vessels.

  In the above embodiment, the fine blood vessel is extracted by performing the frequency filtering process on the B image signal. However, the method of extracting the fine blood vessel is not limited to this. For example, a method of extracting a fine blood vessel from a B / G image composed of a luminance ratio B / G between the B image signal and the G image signal is also conceivable. In this case, a pixel having a luminance ratio B / G lower than a certain value in the B / G image can be extracted as a fine blood vessel pixel. In this way, the fine blood vessel can be extracted from the B / G image because the balance between the B image signal and the G image signal is constant in the mucous membrane pixel, but in the blue blood vessel in the fine blood vessel pixel. This is because the luminance ratio B / G becomes lower than that of the mucous membrane pixel due to a decrease in the value of the B image signal due to the absorption of hemoglobin.

  In the first embodiment, the phosphor 44 is provided at the distal end portion 24 of the endoscope 12. Alternatively, the phosphor 44 may be provided in the light source device 14. In this case, it is preferable to provide a phosphor 44 between the light guide 41 and the blue laser light source 34.

  The simultaneous endoscope system 10 uses a B image signal, which is a narrowband signal including narrowband wavelength information of blue laser light and blue-violet laser light, for creating a blood vessel suppression / inverted image. In the frame sequential endoscope system 200, a Bn image signal, which is a narrowband signal including narrowband wavelength information of blue narrowband light, is used to create a blood vessel suppression / inversion image. A blue narrowband image signal having a lot of information related to the gland duct structure may be generated by spectral calculation based on the image, and this blue narrowband image signal may be used to create a blood vessel suppression / inversion image.

  In this case, white light is illuminated instead of the special light in the second special observation mode of the simultaneous endoscope system 10. Then, as shown in FIG. 23, a spectral calculation unit 300 provided between the reception unit 54 and the blood vessel suppression unit 78 performs a spectral calculation process based on an RGB image signal obtained by light emission and imaging of white light. Thereby, a blue narrow band image signal having a lot of information related to the gland duct structure (for example, a blue narrow band image signal having wavelength information of 415 nm) is generated. The method described in JP-A-2003-093336 is used as the spectroscopic calculation method. Based on the blue narrow-band image signal and the GR image signal generated by the spectral calculation unit 300, a blood vessel suppression / inversion image is generated in the same procedure as in the above embodiment. In addition, as white light, white light emitted from a broadband light source such as a xenon lamp may be used in addition to white light obtained by the phosphor 44.

  In the above embodiment, the present invention is performed during the diagnosis of the endoscope. However, the present invention is not limited thereto, and the endoscope is recorded in the recording unit of the endoscope system after the endoscope diagnosis. You may implement this invention based on an image. In this case, in the endoscope system, it is necessary to provide an image input unit for inputting an image in the recording unit to the processor device.

10,200 Endoscope system 47 Zooming lens (magnifying means)
48,206 Sensor (image input unit)
65 Second special light image processing unit (suppression / inversion processing unit)
78 Blood vessel suppression part (suppression part)
79 Gradation inversion unit (first gradation inversion unit, second gradation inversion unit)
79b Lab converter (separator)
79c RGB converter 110 Blood vessel suppression image 112 Blood vessel suppression / reversed images 125a to 125c, 180a to 180c Tone curves for RGB image data 127a to 127c, 182a to 182c For L data, a data, b data

Claims (7)

A blue-violet semiconductor light emitting device emitting blue-violet light;
A blue semiconductor light emitting device emitting blue light;
A light source controller that individually controls light emission of the blue-violet semiconductor light-emitting element and the blue semiconductor light-emitting element;
A normal light image processing unit that performs a process of obtaining a normal light image on an image obtained by imaging the specimen illuminated with the light including the blue light;
A first special light image processing unit that performs a process of obtaining a first special light image on an image obtained by imaging the specimen illuminated with the blue-violet light and the light containing the blue light;
A second special light image that performs processing for obtaining a second special light image different from the first special light image on an image obtained by imaging the specimen illuminated with the blue-violet light and the light containing the blue light. A processing unit;
A normal observation mode for performing a process for obtaining the normal light image, a first special observation mode for performing a process for obtaining the first special light image in which a light emission ratio of the blue-violet light is larger than the normal observation mode, and A mode switching unit that switches between a second special observation mode in which a light emission ratio of blue-violet light is larger than that in the normal observation mode and the second special light image is processed ;
The second special light image is an endoscope system in which a gland duct structure is clarified and microvessels are suppressed . A blue-violet semiconductor light emitting device emitting blue-violet light;
A blue semiconductor light emitting device emitting blue light;
A light source controller that individually controls light emission of the blue-violet semiconductor light-emitting element and the blue semiconductor light-emitting element;
A normal light image processing unit that performs a process of obtaining a normal light image on an image obtained by imaging the specimen illuminated with the light including the blue light;
A first special light image processing unit that performs a process of obtaining a first special light image on an image obtained by imaging the specimen illuminated with the blue-violet light and the light containing the blue light;
A second special light image that performs processing for obtaining a second special light image different from the first special light image on an image obtained by imaging the specimen illuminated with the blue-violet light and the light containing the blue light. A processing unit;
A normal observation mode for performing a process for obtaining the normal light image, a first special observation mode for performing a process for obtaining the first special light image in which a light emission ratio of the blue-violet light is larger than the normal observation mode, and A mode switching unit that switches between a second special observation mode in which a light emission ratio of blue-violet light is larger than that in the normal observation mode and the second special light image is processed;
The second special light image is an image including a gland duct structure and a dark blood vessel that is darker than the gland duct structure. An endoscope system obtained by performing gradation inversion processing for darkening .   The endoscope system according to claim 1 or 2, wherein the second special light image is close to an image obtained when a blue pigment is dispersed. The endoscope system according to any one of claims 1 to 3, wherein the first special light image highlights a gland duct structure and a fine blood vessel. The normal light image processing unit, the blue-violet light and illuminated specimen with light containing the blue light to the image obtained by imaging, either 4 claims 1 performs a process for obtaining the normal light image The endoscope system according to claim 1. The endoscope system according to any one of claims 1 to 5 , wherein the normal light image has a color tone equivalent to an image obtained when white light is illuminated. The endoscope system according to any one of claims 1 to 6, wherein in the normal observation mode, a light emission ratio of the light including the blue light is appropriately set according to a scope type.