JP5389742B2 - Electronic endoscope system, processor device for electronic endoscope, and method for operating electronic endoscope system - Google Patents

Description

The present invention relates to an electronic endoscope system that acquires information related to blood vessels from an image captured by an electronic endoscope, displays the acquired information, a processor device for the electronic endoscope , and a method for operating the electronic endoscope system About.

  In the medical field in recent years, many diagnoses and treatments using an electronic endoscope have been performed. The electronic endoscope includes an elongated insertion portion that is inserted into the body cavity of a subject, and an imaging device such as a CCD is built in the distal end of the insertion portion. Further, the electronic endoscope is connected to the light source device, and the light emitted from the light source device is irradiated to the inside of the body cavity from the distal end of the insertion portion. In this manner, the subject tissue in the body cavity is imaged by the imaging device at the distal end of the insertion portion in a state where light is irradiated inside the body cavity. An image obtained by imaging is displayed on a monitor after various processing is performed by a processor device connected to the electronic endoscope. Therefore, by using an electronic endoscope, an image in the body cavity of the subject can be confirmed in real time, so that diagnosis and the like can be performed reliably.

  A white light source such as a xenon lamp capable of emitting white broadband light having a wavelength ranging from a blue region to a red region is used for the light source device. By using white broadband light for irradiation in the body cavity, the entire subject tissue can be grasped from the captured image. However, although it is possible to roughly grasp the entire subject tissue from the captured image obtained when the broadband light is irradiated, an uneven structure such as a fine blood vessel, a deep blood vessel, a pit pattern (gland opening structure), a depression or a bump It may be difficult to observe the subject tissue such as clearly. It is known that such a subject tissue can be clearly observed by irradiating narrow band light whose wavelength is limited to a specific region. It is also known to acquire various types of information related to a subject tissue such as oxygen saturation in blood vessels from image data when narrow band light is irradiated, and to image the acquired information.

  For example, in Patent Document 1, three types of narrow-band light, that is, R-color light, G-color light, and B-color light, are irradiated, and imaging is performed for each color light irradiation. Since the light has a characteristic of reaching a deep blood vessel as the wavelength is increased, that is, the wavelength is increased in the order of B color, G color, and R color, the surface blood vessel is exposed to G color light when irradiated with B color light. An image is obtained in which the middle layer blood vessel is emphasized during irradiation with R, and the deep layer blood vessel is emphasized during irradiation with R light. In addition, by performing color image processing based on image data obtained at the time of irradiation with light of each color, the surface blood vessels, the middle blood vessels, and the deep blood vessels are distinguished and imaged with different colors.

  Further, in Patent Document 2, the near-infrared narrow-band light IR1 and IR3 in which the blood vessel absorbance changes due to the change in oxygen saturation and the near-infrared narrow-band light IR2 in which the blood vessel absorbance does not change are irradiated. However, imaging is performed for each light irradiation. Then, a change in luminance between the images is calculated based on the image when the narrow-band light IR1, IR3 in which the absorbance of the blood vessel changes is irradiated and the image when the narrow-band light IR2 in which the absorbance does not change is irradiated. The brightness change is reflected in the image in monochrome or pseudo color. From this image, information on the oxygen saturation in the blood vessel can be obtained.

  Furthermore, in Patent Document 3, narrowband light near a wavelength of 650 nm where the absorbance of the blood vessel changes due to a change in oxygen saturation, narrowband light near a wavelength of 569 nm and narrowband light near a wavelength of 800 nm, where the absorbance of the blood vessel does not change, The information about the distribution of the amount of hemoglobin and the information about the degree of oxygen saturation are simultaneously acquired from the image obtained when the light is irradiated, and these two pieces of information are reflected in the captured image as a color image.

Japanese Patent No. 3559755 Japanese Patent No. 2648494 Japanese Patent No. 2761238

  In recent years, there has been a demand for diagnosis and the like while simultaneously grasping both the blood vessel depth and the oxygen saturation. However, simultaneous acquisition of both hemoglobin amount and oxygen saturation is possible by irradiation with narrowband light as shown in Patent Document 3, but simultaneous acquisition of both blood vessel depth and oxygen saturation is currently However, it is not easy due to various factors such as the absorbance of hemoglobin in the blood vessel changes significantly depending on the wavelength (see FIG. 3).

  For example, as disclosed in Patent Document 1, information on blood vessel depth can be obtained by irradiating three types of narrowband light of R color light, G color light, and B color light. No information about the degree can be obtained. On the other hand, as in Patent Document 2, information on oxygen saturation can be obtained by irradiating narrow-band light IR1, IR2, IR3 in the near infrared region, but information on blood vessel depth cannot be obtained. . And even if the light which satisfy | fills the wavelength range of both patent document 1 and patent document 2 is irradiated, it is difficult to acquire both the information regarding blood vessel depth and the information regarding oxygen saturation simultaneously.

The present invention has been made in view of the above problems, and is an electronic endoscope system capable of simultaneously acquiring both information relating to blood vessel depth and information relating to oxygen saturation and simultaneously displaying the two pieces of information. An object of the present invention is to provide a processor device for an electronic endoscope and an operating method of the electronic endoscope system .

  In order to achieve the above object, an electronic endoscope system according to the present invention is configured to irradiate a subject tissue including a blood vessel in a body cavity with illumination light including a wavelength region of 450 nm or less, and to image the subject tissue. An electronic endoscope having an imaging element that outputs an imaging signal representing the brightness of reflected light reflected by the subject tissue, and first to third narrowband signals included in the imaging signal. Narrow-band signal acquisition means for acquiring first to third narrow-band signals corresponding to first to third narrow-band lights having different wavelength regions and at least one of the center wavelengths being 450 nm or less; Based on the first to third narrowband signals, blood vessel information acquisition means for obtaining blood vessel information including both blood vessel depth and oxygen saturation, and blood vessel information of both blood vessel depth and oxygen saturation are displayed on the monitor. Control to display simultaneously Characterized in that it comprises a that display control means. In addition, as an example of the center wavelength of the first and second narrowband light, a pattern with a wavelength of 445 and 473 nm, a pattern with a wavelength of 405 and 445 nm, a pattern with a wavelength of 405 nm and 473 nm, and the like can be considered. It may be.

  It is preferable to include a blood vessel image generation means for generating a display image reflecting the blood vessel information. It is preferable that the blood vessel image generation means reflects blood vessel information as color information or single color shading information.

  The blood vessel image generation means includes a blood vessel depth image in which a blood vessel having a blood vessel depth of a certain level or more is emphasized over other blood vessels, and an oxygen saturation level in which a blood vessel having a certain degree of oxygen saturation is emphasized over other blood vessels. It is preferable that two images are generated, and the display control means displays the two display images side by side on a monitor screen.

  A first color table for storing blood vessel depth and color information in association with each other; and a second color table for storing oxygen saturation and color information in association with each other, and using the first color table, the blood vessels The color information corresponding to the blood vessel depth obtained by the information acquisition means is specified, and the color information corresponding to the oxygen saturation obtained by the blood vessel information acquisition means is specified and specified using the second color table. It is preferable to reflect color color information in the display image.

  The blood vessel image generation means generates two images, a blood vessel depth image reflecting color information corresponding to blood vessel depth and an oxygen saturation image reflecting color information corresponding to oxygen saturation, and the display control Preferably, the means displays the two display images side by side on a monitor screen.

  It is preferable that the blood vessel image generation unit generates one display image in which one of the blood vessel depth and the oxygen saturation is reflected in a partial region and the other is reflected in the remaining region. It is preferable that the partial area can be specified at an arbitrary position in the display image. It is preferable that the partial region is automatically attached to a blood vessel in which either one of the blood vessel depth or the oxygen saturation is a constant value or a certain range. It is preferable that the partial region is automatically attached to a blood vessel whose blood vessel depth is a constant value or a predetermined range and whose oxygen saturation is a constant value or a predetermined range.

  The display image includes a body cavity image that displays the entire body cavity and a blood vessel display image that is displayed in a region different from the body cavity image and displays blood vessels in a predetermined region in the body cavity. It is preferable that blood vessel depth or oxygen saturation is reflected in at least one of the blood vessel display images. In the blood vessel display image, it is preferable that blood vessels in a predetermined region in the body cavity are displayed in different images at a certain depth. The blood vessel display image is preferably composed of a surface blood vessel image, a middle blood vessel image, and a deep blood vessel image. The blood vessel display image is preferably displayed by enlarging a blood vessel in a predetermined region in the body cavity.

  The blood vessel image generation means reflects color information corresponding to the blood vessel depth in a part of one blood vessel in the display image, and the oxygen saturation is applied to other parts in the same blood vessel. It is preferable to reflect the corresponding color information. In the one blood vessel, it is preferable to reflect one of the two color information of the blood vessel depth and the oxygen saturation at the both ends with the tube axis as the center and the other at the central portion.

  It is preferable that the blood vessel image generation unit reflects the color information corresponding to the oxygen saturation only for a blood vessel having a specific depth in the display image. It is preferable that the blood vessel image generation unit suppresses contrast of a portion other than the blood vessel having the specific depth.

  It is preferable that the first and second color tables have one of a hue circle between two colors and a gradation between two colors as color information. In the first color table, the blood vessel depth is divided into a plurality of stages, and a different color is assigned to each stage. In the second color table, the oxygen saturation is divided into a plurality of stages and is different for each stage. It is preferable to assign a color. It is preferable that the first and second color tables have a plurality of tables that can be switched according to the observation site.

  In the display image, a color bar indicating the correspondence between the blood vessel depth and the color assigned in the first color table, and the correspondence between the oxygen saturation and the color assigned in the second color table. Preferably, at least one of the color bars indicating the relationship is displayed.

  The blood vessel information acquisition means obtains a blood vessel depth and an oxygen saturation, and obtains a blood vessel thickness based on the imaging signal. In the display image, at least one of the blood vessel thickness or the blood vessel depth and oxygen saturation are obtained. It is preferable that a blood vessel in which the degree is reflected as color information or density information of one color is displayed. The blood vessel information acquisition means obtains blood vessel depth and oxygen saturation, and obtains blood vessel density based on the imaging signal. In the display image, at least one of blood vessel density or blood vessel depth and oxygen saturation is obtained. It is preferable that a blood vessel reflecting the color information or color information of one color is displayed. The blood vessel information acquisition means obtains a blood vessel depth and oxygen saturation, obtains fluorescence intensity based on the imaging signal when fluorescence is emitted from a tumor affected part by administration of a fluorescent agent, and displays the display In the image for use, it is preferable to display a blood vessel in which at least one of fluorescence intensity or blood vessel depth and oxygen saturation is reflected as color information or light and shade information of one color. The blood vessel information acquisition means obtains blood vessel depth and oxygen saturation, and obtains blood concentration based on the imaging signal. In the display image, at least one of blood concentration or blood vessel depth and oxygen saturation is obtained. It is preferable that a blood vessel reflecting the color information or color information of one color is displayed. The blood vessel information acquisition means obtains a blood vessel depth and an oxygen saturation, and obtains a blood vessel shape based on the imaging signal. In the display image, at least one of the blood vessel shape or the blood vessel depth and oxygen saturation are obtained. It is preferable that a blood vessel in which the degree is reflected as color information or density information of one color is displayed.

  A third color table that associates and stores color information of one color for each combination of blood vessel depth and oxygen saturation, and the blood vessel depth and oxygen determined by the blood vessel information acquisition unit using the third color table A color information specifying unit that specifies color information corresponding to a combination of saturation degrees, and the blood vessel image generation unit is configured to determine the color specified by the color information specifying unit for an image obtained based on the imaging signal. It is preferable to reflect information. The third color table associates color information of one color for each combination of blood vessel depth and oxygen saturation by assigning a color wheel to a blood vessel information coordinate system indicating the blood vessel depth and oxygen saturation. It is preferable to memorize. It is preferable that the third color table has a plurality of tables that can be switched according to the observation site.

  The imaging device is a monochrome imaging device, and the irradiating means irradiates light of three colors of R, G, and B in a time-division manner and time-divisions the first and second narrowband lights. The field sequential normal light that generates the normal light image based on the imaging signal obtained by irradiating the light of three colors of R, G, and B in a time-sharing manner It is preferable to have image generation means. The image pickup device has three color pixels of R pixel, G pixel, and B pixel provided with three color filters of R color, G color, and B color. A white broadband light including a wavelength region from a blue region to a red region to which each pixel of B is sensitive is possible, and a normal light image is obtained based on an imaging signal obtained by irradiating the broadband light. It is preferable to have simultaneous normal light image generating means for generating. The image pickup device has three color pixels of C pixel, M pixel, and Y pixel provided with three color filters of C color, M color, and Y color. , Y can irradiate white broadband light including the wavelength region from the blue region to the red region to which each pixel is sensitive, and the normal light image can be obtained based on the imaging signal obtained by irradiating the broadband light. It is preferable to have simultaneous normal light image generating means for generating.

  The processor device for an electronic endoscope of the present invention is obtained by irradiating illumination light including a wavelength region of 450 nm or less and imaging a subject tissue including a blood vessel in a body cavity with an imaging device of the electronic endoscope. Receiving means for receiving an imaging signal representing the brightness of reflected light reflected by the illumination light from the electronic endoscope; and first to third narrowband signals included in the imaging signal; Narrowband signal acquisition means for acquiring first to third narrowband signals corresponding to first to third narrowband lights having different wavelength regions and at least one of the center wavelengths being 450 nm or less; Based on the first to third narrowband signals, blood vessel information acquisition means for obtaining blood vessel information including both blood vessel depth and oxygen saturation, and blood vessel information of both blood vessel depth and oxygen saturation are simultaneously displayed on the monitor. Control to be displayed Characterized in that it comprises a 示制 control means.

In the operating method of the electronic endoscope system according to the present invention, the illumination means emits illumination light including a wavelength region of 450 nm or less, and the imaging element images the subject tissue including blood vessels in the body cavity. The step of obtaining an imaging signal representing the brightness of the reflected light reflected by the tissue of the illumination light and the narrowband signal acquisition means are the first to third narrowband signals included in the imaging signal, and have different wavelengths. Obtaining the first to third narrowband signals corresponding to the first to third narrowband lights having a region and at least one of the center wavelengths being 450 nm or less, and blood vessel information obtaining means, Based on the first to third narrowband signals, the step of obtaining the blood vessel information including both the blood vessel depth and the oxygen saturation, and the display control means, the blood vessel information of both the blood vessel depth and the oxygen saturation are displayed on the monitor. Simultaneous display And a step of controlling as described above.

  According to the present invention, first and second narrowband signals corresponding to first and second narrowband lights having at least one center wavelength of 450 nm or less are obtained, and the first and second narrowband signals are obtained. Based on the signal, blood vessel information including both the blood vessel depth and the oxygen saturation is obtained, and control is performed so that this blood vessel information is simultaneously displayed on the monitor. Both can be acquired at the same time and the two pieces of information can be displayed simultaneously.

1 is an external view of an electronic endoscope system according to a first embodiment of the present invention. It is a block diagram which shows the electric constitution of the electronic endoscope system of 1st Embodiment. It is a graph which shows the light transmittance distribution of the spectral transmittance and broadband light BB and 1st-3rd narrow-band light N1-N3 in B pixel of a primary color system color CCD, G pixel, and R pixel. (A) is an explanatory diagram for explaining the CCD imaging operation in the normal light image mode, and (B) is an explanatory diagram for explaining the CCD imaging operation in the special light image mode. It is a graph which shows the absorption coefficient of hemoglobin. It is a graph which shows the correlation with 1st and 2 brightness | luminance ratio S1 / S3, S2 / S3, blood vessel depth, and oxygen saturation. (A) is a method of obtaining coordinates (X ^* , Y ^* ) in the luminance coordinate system from the first and second luminance ratios S1 ^* / S3 ^* , S2 ^* / S3 ^* , and (B) is a coordinate (X ^* , Y ^*). FIG. 9 is an explanatory diagram for explaining a method for obtaining coordinates (U ^* , V ^* ) of the blood vessel information coordinate system corresponding to (). (A) is a block diagram showing a specific configuration in the blood vessel depth image generation unit, and (B) a specific configuration in the oxygen saturation image generation unit. (A) is a graph showing a two-color hue ring corresponding to the blood vessel depth, and (B) is a graph showing a two-color hue ring corresponding to oxygen saturation. (A) is a graph showing the density corresponding to the blood vessel depth, and (B) is a graph showing gradation between two colors corresponding to the blood vessel depth. It is the graph which represented the blood vessel depth divided into the color of three steps. It is an image figure of the monitor in which both a blood vessel depth image or an oxygen saturation image is displayed simultaneously. It is an image figure of the monitor in which both a blood vessel depth image or an oxygen saturation image is displayed simultaneously. It is a flowchart which shows the procedure which calculates the procedure which calculates blood vessel depth-oxygen saturation, and the blood vessel depth image and oxygen saturation image which reflected them. It is an image figure of the monitor in which the designated area | region which reflected oxygen saturation was provided in the blood vessel depth image. It is an image figure of the broadband optical image which displays the blood vessel in a designated area | region divided into a surface layer, a middle layer, and a deep layer. It is explanatory drawing for demonstrating that a frame is automatically attached with respect to the blood vessel whose oxygen saturation is a fixed value or a fixed range. It is explanatory drawing for demonstrating that a frame is automatically attached with respect to the blood vessel whose blood vessel depth is a fixed value or a fixed range in addition to oxygen saturation being a fixed value or a fixed range. It is explanatory drawing for demonstrating that the frame which displays the blood vessel whose oxygen saturation is a fixed value or a fixed range is displayed in parts other than the image in a body cavity. It is a block diagram which shows the specific structure of the blood-vessel image generation part in 2nd Embodiment of this invention. It is the graph by which the hue circle was allocated to UV coordinate system. It is an image figure of the monitor which shows the wideband image in which the color information of one color allocated for every combination of blood vessel depth and oxygen saturation was reflected. It is a part of the image figure of the monitor which reflected the color information corresponding to each of blood vessel depth and oxygen saturation with one blood vessel image. It is an image figure of the monitor which displays the blood vessel depth and oxygen saturation as character information. It is an image figure of the monitor which emphasized the blood vessel image of the surface blood vessel. It is explanatory drawing for demonstrating that the color information of oxygen saturation is reflected with respect to the blood vessel whose blood vessel thickness is a fixed value or a fixed range. It is explanatory drawing for demonstrating reflecting the color information of oxygen saturation with respect to the blood vessel in the area where the blood vessel density is a fixed value or a fixed range. It is explanatory drawing for demonstrating reflecting the color information of oxygen saturation with respect to the blood vessel in the area where the fluorescence intensity of a fluorescent agent is a fixed value or a fixed range. It is explanatory drawing for demonstrating that the color information of oxygen saturation is reflected with respect to the blood vessel whose blood concentration is a fixed value or a fixed range. It is the schematic of an electronic endoscope system provided with the rotary filter provided with the filter which permeate | transmits the light used at the time of normal light image mode and special light image mode. It is the schematic of the rotary filter provided with the filter which permeate | transmits the light used at the time of normal light image mode and special light image mode. It is the schematic of the rotary filter corresponding to a field sequential system. It is the schematic of the rotary filter of a field sequential system from which the arrangement | sequence of each filter differs from the rotary filter of FIG. (A) illustrates the imaging operation in the special light image mode when the rotary filter of FIG. 32 is used, and (B) describes the imaging operation in the special light image mode when the rotary filter of FIG. 33 is used. FIG. It is a graph which shows the spectral transmittance in C pixel, M pixel, and Y pixel of complementary color type CCD, and the light intensity distribution of broadband light BB and 1st-3rd narrow-band light N1-N3.

  As shown in FIG. 1, an electronic endoscope system 10 according to a first embodiment of the present invention includes an electronic endoscope 11 that images a body cavity of a subject, and a body cavity based on a signal obtained by the imaging. A processor device 12 for generating an image of the subject tissue, a light source device 13 for supplying light for irradiating the inside of the body cavity, and a monitor 14 for displaying the image in the body cavity. The electronic endoscope 11 includes a flexible insertion portion 16 to be inserted into a body cavity, an operation portion 17 provided at a proximal end portion of the insertion portion 16, an operation portion 17, a processor device 12, and a light source device 13. And a universal cord 18 for connecting the two.

  A bending portion 19 in which a plurality of bending pieces are connected is formed at the distal end of the insertion portion 16. The bending portion 19 is bent in the vertical and horizontal directions by operating the angle knob 21 of the operation portion. The distal end of the bending portion 19 is provided with a distal end portion 16a incorporating an optical system for in-vivo imaging, and the distal end portion 16a is directed in a desired direction in the body cavity by the bending operation of the bending portion 19. .

  A connector 24 is attached to the universal cord 18 on the processor device 12 and the light source device 13 side. The connector 24 is a composite type connector including a communication connector and a light source connector, and the electronic endoscope 11 is detachably connected to the processor device 12 and the light source device 13 via the connector 24.

  As illustrated in FIG. 2, the light source device 13 includes a broadband light source 30, a shutter 31, a shutter driving unit 32, first to third narrowband light sources 33 to 35, a coupler 36, and a light source switching unit 37. I have. The broadband light source 30 is a xenon lamp, a white LED, a micro white light source, or the like, and generates broadband light BB having a wavelength ranging from a red region to a blue region (about 470 to 700 nm). The broadband light source 30 is always lit while the electronic endoscope 11 is in use. The broadband light BB emitted from the broadband light source 30 is collected by the condenser lens 39 and enters the broadband optical fiber 40.

  The shutter 31 is provided between the broadband light source 30 and the condenser lens 39. The shutter 31 is inserted in the optical path of the broadband light BB to block the broadband light BB, and the broadband light BB is retracted from the insertion position. It is movable between a retracted position that allows it to go to the condenser lens 39. The shutter drive unit 32 is connected to a controller 59 in the processor device, and controls the drive of the shutter 31 based on an instruction from the controller 59.

  The first to third narrowband light sources 33 to 35 are laser diodes or the like, and the first narrowband light source 33 has a narrowband light whose wavelength is limited to 440 ± 10 nm, preferably 445 nm (hereinafter referred to as “first narrowband light source”). The second narrowband light source 34 is a narrowband light whose wavelength is limited to 470 ± 10 nm, preferably 473 nm (hereinafter referred to as “second narrowband light N2”). The three narrow-band light sources 35 generate narrow-band light (hereinafter referred to as “third narrow-band light N3”) whose wavelength is limited to 400 ± 10 nm, preferably 405 nm. The first to third narrowband light sources 33 to 35 are respectively connected to the first to third narrowband optical fibers 33a to 35a, and the first to third narrowband lights N1 to N3 emitted from the respective light sources are The light enters the first to third narrowband optical fibers 33a to 35a.

  The coupler 36 connects the light guide 43 in the electronic endoscope to the broadband optical fiber 40 and the first to third narrowband optical fibers 33a to 35a. Thereby, the broadband light BB can be incident on the light guide 43 via the broadband optical fiber 40. Further, the first to third narrowband lights N1 to N3 can enter the light guide 43 via the first to third narrowband optical fibers 33a to 35a.

  The light source switching unit 37 is connected to a controller 59 in the processor device, and switches the first to third narrowband light sources 33 to 35 to ON (lit) or OFF (dark) based on an instruction from the controller 59. In the first embodiment, when the normal light image mode using the broadband light BB is set, the broadband light source 30 is switched on to capture the normal light image, while the first to third narrow light sources are captured. The band light sources 33 to 35 are turned off. On the other hand, when the special light image mode using the first to third narrowband lights N1 to N3 is set, the first to third narrowband light sources 33 to 35 are sequentially switched on. A special light image is captured. Under the special light image mode, the broadband light BB does not enter the light guide 43 because the shutter 31 is set at the insertion position.

  Specifically, first, the first narrowband light source 33 is switched ON by the light source switching unit 37. The subject tissue is imaged in a state where the first narrowband light N1 is irradiated into the body cavity. When the imaging is completed, a light source switching instruction is issued from the controller 59, and the first narrow band light source 33 is switched OFF and the second narrow band light source 34 is switched ON. When the imaging with the second narrowband light N2 applied to the body cavity is completed, the second narrowband light source 34 is switched off and the third narrowband light source 35 is switched on similarly. Furthermore, when the imaging in the state where the third narrowband light N3 is irradiated into the body cavity is completed, the third narrowband light source 35 is switched off.

  The electronic endoscope 11 includes a light guide 43, a CCD 44, an analog processing circuit 45 (AFE: Analog Front End), and an imaging control unit 46. The light guide 43 is a large-diameter optical fiber, a bundle fiber, or the like. The incident end is inserted into the coupler 36 in the light source device, and the emission end is directed to the irradiation lens 48 provided at the distal end portion 16a. The light emitted from the light source device 13 is guided by the light guide 43 and then emitted toward the irradiation lens 48. The light incident on the irradiation lens 48 is irradiated into the body cavity through the illumination window 49 attached to the end surface of the distal end portion 16a. The broadband light BB and the first to third narrowband lights N1 to N3 reflected in the body cavity enter the condenser lens 51 through the observation window 50 attached to the end surface of the distal end portion 16a.

  The CCD 44 receives light from the condensing lens 51 on the imaging surface 44a, photoelectrically converts the received light to accumulate signal charges, and reads the accumulated signal charges as imaging signals. The read imaging signal is sent to the AFE 45. The CCD 44 is a color CCD, and on the imaging surface 44a, pixels of three colors of R pixel, G pixel, and B pixel provided with any color filter of R color, G color, and B color are arranged. Yes.

  The R, G, and B color filters have spectral transmittances 52, 53, and 54 as shown in FIG. Of the light incident on the condensing lens 51, the broadband light BB has a wavelength of about 470 to 700 nm, so that the R, G, and B color filters have the spectral transmittances 52 and 53 of the broadband light BB, respectively. , 54 is transmitted. Here, when the signal photoelectrically converted by the R pixel is the imaging signal R, the signal photoelectrically converted by the G pixel is the imaging signal G, and the signal photoelectrically converted by the B pixel is the imaging signal B, the broadband light BB is input to the CCD 44. When incident, a wide-band imaging signal composed of the imaging signal R, the imaging signal G, and the imaging signal B is obtained.

  On the other hand, the first narrow-band light N1 out of the light incident on the condenser lens 51 has a wavelength of 440 ± 10 nm, and therefore passes only through the B color filter. Accordingly, when the first narrowband light N1 is incident on the CCD 44, a first narrowband imaging signal composed of the imaging signal B is obtained. Further, since the second narrowband light N2 has a wavelength of 470 ± 10 nm, the second narrowband light N2 passes through the B color filter and the G color filter. Therefore, when the second narrowband light N2 is incident on the CCD 44, a second narrowband imaging signal composed of the imaging signal B and the imaging signal G is obtained. Further, since the third narrowband light N3 has a wavelength of 400 ± 10 nm, it transmits only the B color filter. Accordingly, when the third narrowband light N3 is incident on the CCD 44, a third narrowband imaging signal composed of the imaging signal B is obtained.

  The AFE 45 includes a correlated double sampling circuit (CDS), an automatic gain control circuit (AGC), and an analog / digital converter (A / D) (all not shown). The CDS performs correlated double sampling processing on the image pickup signal from the CCD 44 to remove noise generated by driving the CCD 44. The AGC amplifies the imaging signal from which noise has been removed by CDS. The A / D converts the imaging signal amplified by the AGC into a digital imaging signal having a predetermined number of bits and inputs the digital imaging signal to the processor device 12.

  The imaging control unit 46 is connected to a controller 59 in the processor device 12, and sends a drive signal to the CCD 44 when an instruction is given from the controller 59. The CCD 44 outputs an imaging signal to the AFE 45 at a predetermined frame rate based on the drive signal from the imaging control unit 46. In the first embodiment, when the normal light image mode is set, as shown in FIG. 4A, the step of accumulating signal charges by photoelectrically converting the broadband light BB within an acquisition period of one frame; A total of two operations are performed, including the step of reading the accumulated signal charge as a broadband imaging signal. This operation is repeated while the normal light image mode is set.

  On the other hand, when the normal light image mode is switched to the special light image mode, first, as shown in FIG. 4B, the first narrowband light N1 is photoelectrically converted within the acquisition period of one frame. Thus, a total of two operations are performed: a step of accumulating signal charges, and a step of reading the accumulated signal charges as the first narrowband imaging signal. When the reading of the first narrowband imaging signal is completed, the step of photoelectrically converting the second narrowband light N2 to accumulate the signal charge within the acquisition period of one frame, and the accumulated signal charge to the second narrowband imaging signal Are read out. When the reading of the second narrowband imaging signal is completed, the step of photoelectrically converting the third narrowband light N3 and accumulating the signal charge within the acquisition period of one frame, and the accumulated signal charge as the third narrowband imaging signal Are read out.

  As shown in FIG. 2, the processor device 12 includes a digital signal processing unit 55 (DSP (Digital Signal Processor)), a frame memory 56, a blood vessel image generation unit 57, and a display control circuit 58. Controls each part. The DSP 55 performs wideband image data by performing color separation, color interpolation, white balance adjustment, gamma correction, and the like on the wideband imaging signal and the first to third narrowband imaging signals output from the AFE 45 of the electronic endoscope. And 1st-3rd narrow-band image data are produced. The frame memory 56 stores the broadband image data and the first to third narrowband image data created by the DSP 55. The broadband image data is color image data including R color, G color, and B color.

  The blood vessel image generation unit 57 includes a luminance ratio calculation unit 60, a correlation storage unit 61, a blood vessel depth-oxygen saturation calculation unit 62, a blood vessel depth image generation unit 63, and an oxygen saturation image generation unit 64. It has. The luminance ratio calculation unit 60 specifies a blood vessel region including a blood vessel from the first to third narrowband light image data stored in the frame memory 56. The luminance ratio calculation unit 60 obtains the first luminance ratio S1 / S3 between the first and third narrowband image data for the pixels at the same position in the blood vessel region, and the second and third narrowband image data. A second luminance ratio S2 / S3 is obtained. Here, S1 is the luminance value of the pixel of the first narrowband light image data, S2 is the luminance value of the pixel of the second narrowband light image data, and S3 is the luminance value of the pixel of the third narrowband light image data. Represents. As a method for specifying the blood vessel region, for example, there is a method for obtaining the blood vessel region from the difference between the luminance value of the blood vessel portion and the other luminance values.

The correlation storage unit 61 stores the correlation between the first and second luminance ratios S1 / S3, S2 / S3, the oxygen saturation level in the blood vessel, and the blood vessel depth. This correlation is a correlation when the blood vessel has the hemoglobin extinction coefficient shown in FIG. 5, and by analyzing a large number of first to third narrow-band optical image data accumulated in the diagnosis so far. It is obtained. As shown in FIG. 5, hemoglobin in a blood vessel has a light absorption characteristic in which the light absorption coefficient μa changes depending on the wavelength of light to be irradiated. The extinction coefficient μa represents an absorbance that is the magnitude of light absorption of hemoglobin, and is a coefficient of an expression of I ₀ exp (−μa × x) representing the attenuation state of light irradiated to hemoglobin. Here, I ₀ is the intensity of light emitted from the light source device to the subject tissue, and x (cm) is the depth to the blood vessel in the subject tissue.

  Further, the reduced hemoglobin 70 not bound to oxygen and the oxygenated hemoglobin 71 bound to oxygen have different light absorption characteristics and have the same absorption point (absorption coefficient μa) (each hemoglobin 70, FIG. Except for 71 intersection points), there is a difference in absorbance. If there is a difference in absorbance, the luminance value changes even if the same blood vessel is irradiated with light of the same intensity and the same wavelength. Further, even when light of the same intensity is irradiated, if the wavelength is different, the extinction coefficient μa changes, so that the luminance value changes.

  Considering the light absorption characteristics of hemoglobin as described above, there are 445 nm and 473 nm wavelengths that differ in absorbance depending on oxygen saturation, and a short wavelength region with a short depth of penetration is necessary for blood vessel depth information extraction. Therefore, it is preferable that the first to third narrowband lights N1 to N3 include at least one narrowband light having a wavelength region with a center wavelength of 450 nm or less. Such narrow-band light corresponds to first and second narrow-band light in the first embodiment. Moreover, even if the oxygen saturation is the same, the absorption coefficient value is different for different wavelengths, and the depth of penetration in the mucosa is also different. Therefore, the correlation between the brightness ratio and the blood vessel depth can be obtained by using the characteristics of light having a different depth of penetration depending on the wavelength.

  As shown in FIG. 6, the correlation storage unit 61 includes coordinates of the luminance coordinate system 66 representing the first and second luminance ratios S1 / S3 and S2 / S3, and blood vessel information coordinates representing the oxygen saturation and the blood vessel depth. Correlation is stored in association with the coordinates of the system 67. The luminance coordinate system 66 is an XY coordinate system, the X axis represents the first luminance ratio S1 / S3, and the Y axis represents the second luminance ratio S2 / S3. The blood vessel information coordinate system 67 is a UV coordinate system provided on the luminance coordinate system 66. The U axis represents the blood vessel depth and the V axis represents the oxygen saturation. The U axis has a positive slope because the blood vessel depth has a positive correlation with the luminance coordinate system 66. Regarding the U-axis, the blood vessel is shallower as it goes diagonally upward to the right, and the blood vessel is deeper as it goes diagonally downward to the left. On the other hand, since the oxygen saturation has a negative correlation with the luminance coordinate system 66, the V-axis has a negative slope. With respect to this V-axis, the oxygen saturation is lower as it goes to the upper left, and the oxygen saturation is higher as it goes to the lower right.

  In the blood vessel information coordinate system 67, the U axis and the V axis are orthogonal to each other at an intersection point P. This is because the magnitude relationship of light absorption is reversed between when the first narrowband light N1 is irradiated and when the second narrowband light N2 is irradiated. That is, as shown in FIG. 5, when the first narrowband light N1 having a wavelength of 440 ± 10 nm is irradiated, the extinction coefficient of reduced hemoglobin 70 is higher than the extinction coefficient of oxyhemoglobin 71 having high oxygen saturation. On the other hand, when the second narrowband light N2 having a wavelength of 470 ± 10 nm is irradiated, the extinction coefficient of oxyhemoglobin 71 is larger than the extinction coefficient of reduced hemoglobin 70. The magnitude relationship is reversed. In addition, when the narrow band light which does not reverse the magnitude relationship of light absorption is irradiated instead of the first to third narrow band lights N1 to N3, the U axis and the V axis are not orthogonal to each other. When the first narrowband light N1 having a wavelength of 400 ± 10 nm is irradiated, the extinction coefficients of oxyhemoglobin and deoxyhemoglobin are the same.

The blood vessel depth-oxygen saturation calculation unit 62 is based on the correlation in the correlation storage unit 61, and oxygen corresponding to the first and second luminance ratios S1 / S3 and S2 / S3 calculated by the luminance ratio calculation unit 60. Identify saturation and vessel depth. Here, out of the first and second luminance ratios S1 / S3 and S2 / S3 calculated by the luminance ratio calculation unit 60, the first luminance ratio for a predetermined pixel in the blood vessel region is S1 ^* / S3 ^*, and 2. Let the luminance ratio be S2 ^* / S3 ^* .

As shown in FIG. 7A, the blood vessel depth-oxygen saturation calculation unit 62 uses coordinates corresponding to the first and second luminance ratios S1 ^* / S3 ^* , S2 ^* / S3 ^* in the luminance coordinate system 66. Specify (X ^* , Y ^* ). Once the coordinates ^(X *, ^{Y *)} is identified, as shown in FIG. 7 (B), in the blood vessel information coordinate system 67, the coordinates ^(X *, ^{Y *)} corresponding coordinates ^{(U *, V} *) to Identify. Thereby, the blood vessel depth U ^* and the oxygen saturation V ^* are obtained for the pixel at a predetermined position in the blood vessel region. Here, the blood vessel depth is represented by numerical information. The smaller the blood vessel depth, the smaller the numerical value, and the larger the blood vessel depth, the larger the numerical value. The oxygen saturation is also expressed by numerical information, similar to the blood vessel depth.

As shown in FIG. 8A, the blood vessel depth image generation unit 63 includes a color table for stomach 63a, a color table for duodenum 63b, and a color table for small intestine 63c to which color information is assigned according to the size of the blood vessel. It has. These color tables 63a to 63c are selected according to the part to be observed by the switching operation of the console 23. The color table 63a corresponds to the color information corresponding to the blood vessel depth in the stomach, the color table 63b for the duodenum corresponds to the color information corresponding to the blood vessel depth in the duodenum, and the color table 63c for the small intestine corresponds to the blood vessel depth in the small intestine. Color information is assigned. The blood vessel depth image generation unit 63 uses any one of the color tables 63a to 63c selected by the console 23, and uses the color information corresponding to the blood vessel depth U ^* calculated by the blood vessel depth-oxygen saturation calculation unit 62. Is identified. In the first embodiment, three types of color tables for the stomach, duodenum, and small intestine are used, but color tables corresponding to other regions of the subject tissue may be further added.

As shown in FIG. 8 (B), the oxygen saturation image generation unit 64, like the blood vessel depth image generation unit 63, has a stomach color table 64a to which color information is assigned according to the magnitude of oxygen saturation. A color table 64b for the duodenum and a color table 64c for the small intestine are provided. These color tables 64 a to 64 c can also be switched by a switching operation of the console 23. The oxygen saturation image generation unit 64 uses any one of the color tables 64a to 64c selected by the console 23, and color information corresponding to the oxygen saturation V ^* calculated by the blood vessel depth-oxygen saturation calculation unit 62. Is identified.

  As shown in FIG. 9A, the color information of the color tables 63a to 63c of the blood vessel depth image generation unit includes two colors having a complementary color relationship, for example, two colors from R (red) to Cy (cyan). It is represented by a hue between colors. In FIG. 9A, the color information is R when the blood vessel depth is small, and changes in the order of Ye (yellow), G (green), and Cy as the blood vessel depth increases. The color information of the color tables 64a to 64c of the oxygen saturation image generation unit 64 is represented by a hue ring between two colors from Cy to R as shown in FIG. 9B. In FIG. 9B, the color information is Cy when the oxygen saturation is small, and changes in the order of B (blue), M (magenta), and R (red) as the oxygen saturation is increased. The assignment of the two-color rings may be reversed such that the oxygen saturation is from R to Cy and the blood vessel depth is from Cy to R. Further, although different colors are assigned to the oxygen saturation and the blood vessel depth, both the color relating to the oxygen saturation and the color relating to the blood vessel depth are reflected in one blood vessel as shown in the second embodiment below. Except in such cases, the color assignment to the oxygen saturation and the blood vessel depth may both be the same as R → G → Cy.

  In the first embodiment, the color information is represented by a hue circle. However, as shown in FIG. 10A, for achromatic or chromatic colors such as white and black, the color information may be represented by shading, that is, lightness. In FIG. 10A, when the blood vessel depth is small, the blood vessel is darkened (lightness is lowered), and as the blood vessel depth is thickened, it is thinned (lightness is raised).

  Further, as shown in FIG. 10B, the color information may be expressed by gradation between two colors from R to Cy. In FIG. 10B, the color information is expressed by R when the blood vessel depth is small, and the saturation changes between R and Cy according to the blood vessel depth, for example, of two colors having complementary colors. The closer the depth, the closer to Cy. In the case of gradation between two colors, since gray is included in the intermediate value, unlike the two-color hue circle, gray is passed when changing between complementary colors. When the experiment of visibility was performed, the visibility of gradation between two colors has obtained a good result. Further, the color information of the oxygen saturation may be expressed in the same manner as in FIGS. 10 (A) and 10 (B).

  Further, as shown in FIG. 11, the color information of the blood vessel depth may be expressed in a plurality of stages, for example, two stages and three stages. In FIG. 11, the color information is divided into three levels of blue, green, and red according to the blood vessel depth. B (blue) indicates that the blood vessel depth is near the surface layer, and G (green) indicates The blood vessel depth is in the vicinity of the middle layer, and R (red) indicates that the blood vessel depth is in the vicinity of the deep layer. Similarly, the color information of the oxygen saturation is also divided into a plurality of colors depending on the oxygen saturation, for example, 0% to 30% is yellow and 30% to 70% is magenta. May be.

  In the above description, both the blood vessel depth and the oxygen saturation are represented by the same type of color information, but each may be different color information. For example, when the blood vessel depth color information is represented by a two-color ring, the oxygen saturation color information may be represented by shading or gradation between two colors in addition to the two-color ring.

  When the color information is specified for all the pixels in the blood vessel region, the blood vessel depth image generation unit 63 reads the broadband image data from the frame memory 56, and reflects the color information on the read broadband optical image data. Let Thereby, blood vessel depth image data reflecting the blood vessel depth is generated. The generated blood vessel depth image data is stored in the frame memory 56 again. Note that the color information may be reflected not on the broadband optical image data but on any of the first to third narrowband image data or a synthesized image obtained by synthesizing these. In addition, color information may be reflected by converting broadband image data into a monochrome image. Reflecting the first to third narrowband image data or the monochrome image improves the color information discrimination.

  Similar to the blood vessel depth image generating unit 63, the oxygen saturation image generating unit 64 generates oxygen saturation image data by reflecting color information about all pixels in the blood vessel region in the broadband image data. The generated oxygen saturation image data is stored in the frame memory 56 similarly to the blood vessel depth image data.

  The display control circuit 58 displays an image on the monitor based on the image data stored in the frame memory 56. As shown in FIG. 12, a broadband image 72 based on broadband image data is displayed on one side of the monitor 14, and a blood vessel depth image 73 based on blood vessel depth image data and an oxygen saturation level are displayed on the other side. Both the oxygen saturation image 74 based on the image data are displayed. In the blood vessel depth image 73, the blood vessel image 75 is represented by red (R) indicating a surface layer blood vessel, the blood vessel image 76 is represented by green (G) indicating a middle layer blood vessel, and the blood vessel image 77 is represented by cyan (Cy) indicating a deep layer blood vessel. ing. On the other hand, in the oxygen saturation image 74, the blood vessel image 80 is cyan (Cy) indicating low oxygen saturation, the blood vessel image 81 is magenta (M) indicating intermediate oxygen saturation, and the blood vessel image 82 indicates high oxygen saturation. It is represented by red (R).

  A color bar 73a indicating a color circle from R to Cy is displayed in the blood vessel depth image 73, and a color bar 74a indicating a color circle from Cy to R is displayed in the upper right of each screen. Yes. The arrow of the color bar 73a indicates that the blood vessel depth increases from the left end toward the right end. At both ends of the arrow, “shallow (blood vessel depth” is provided so that the correspondence between the blood vessel depth and the color can be easily confirmed. "Is shallow)" and "depth (blood vessel depth is deep)". The arrow and character display of the color bar 74a are the same as those of the color bar 73a. In this way, by displaying the color bars 73a and 74a simultaneously with the blood vessel depth image 73 and the oxygen saturation image 74, the color information, blood vessel depth and the color information reflected in the blood vessel depth image 73 and the oxygen saturation image 74 are displayed. It is easy to confirm the correspondence with oxygen saturation.

  In the blood vessel depth image 73 of FIG. 12, the color given to each blood vessel image 75 to 77 is changed according to the blood vessel depth, and in the oxygen saturation image 74, each blood vessel image 80 to 82 is changed according to the oxygen saturation. In place of this, instead of this, as shown in FIG. 13, in the blood vessel depth image 110, a blood vessel image 117 having a blood vessel depth of a certain level or more is displayed more than the blood vessel images 115 and 116 of less than that. In the oxygen saturation image 111, the blood vessel image 123 having a certain level of oxygen saturation may be emphasized more than the blood vessel images 121 and 122 less than that.

  Next, the procedure for calculating the blood vessel depth-oxygen saturation and the procedure for generating the blood vessel depth image and the oxygen saturation image reflecting them will be described with reference to the flowchart shown in FIG. First, the normal light image mode is switched to the special light image mode by operating the console 23. When switched to the special light image mode, the broadband image data at the time of switching is stored in the frame memory 56 as image data used for generating a blood vessel depth image or an oxygen saturation image. Further, the current observation site such as the stomach, duodenum, and small intestine is designated by operating the console 23. Thereby, any one of the color tables 63a to 63c corresponding to the observation region and any one of the color tables 64a to 64c are selected. Note that the broadband image data used for generating the blood vessel depth image or the like may be the one before the console operation.

  When an irradiation stop signal is sent from the controller 59 to the shutter drive unit 32, the shutter drive unit 32 moves the shutter 31 from the retracted position to the insertion position, and stops the irradiation of the broadband light BB into the body cavity. . When the irradiation of the broadband light BB is stopped, an irradiation start instruction is sent from the controller 59 to the light source switching unit 37. As a result, the light source switching unit 37 turns on the first narrowband light source 33 and irradiates the body cavity with the first narrowband light N1. When the first narrowband light N1 is irradiated into the body cavity, an imaging instruction is sent from the controller 59 to the imaging drive unit 46. Thereby, imaging is performed in a state where the first narrowband light N1 is irradiated, and the first narrowband imaging signal obtained by imaging is sent to the DSP 55 via the AFE45. The DSP 55 generates first narrowband image data based on the first narrowband imaging signal. The generated first narrowband image data is stored in the frame memory 56.

  When the first narrow-band image data is stored in the frame memory 56, the light source switching unit 37 emits light to be irradiated into the body cavity from the first narrow-band light N1 to the second narrow-band light N2 according to the light source switching instruction from the controller 59. Switch to. Then, imaging is performed similarly to the case of the first narrowband light N1, and second narrowband image data is generated based on the second narrowband imaging signal obtained by imaging. The generated second narrowband image data is stored in the frame memory 56.

  When the second narrowband image data is stored in the frame memory 56, the light source switching unit 37 emits light radiated into the body cavity from the second narrowband light N2 to the third narrowband light N3 according to the light source switching instruction from the controller 59. Switch to. Then, imaging is performed in the same manner as in the case of the first and second narrowband lights N1 and N2, and third narrowband image data is generated based on the third narrowband imaging signal obtained by imaging. The generated third narrowband image data is stored in the frame memory 56.

When the broadband image data and the first to third narrowband image data are stored in the frame memory 56, the luminance ratio calculation unit 60 stores the first narrowband image data, the second narrowband image data, and the third narrowband image data. A blood vessel region including a blood vessel is specified from the three image data. Then, for pixels at the same position in the blood vessel region, the first luminance ratio S1 ^* / S3 ^* between the first and second narrowband image data and the second luminance ratio S2 between the second and third narrowband image data. ^* / S3 ^* is calculated.

Next, the blood vessel depth-oxygen saturation calculation unit 62 determines the luminance coordinates corresponding to the first and second luminance ratios S1 ^* / S3 ^* , S2 ^* / S3 ^* based on the correlation in the correlation storage unit 61. Specify system coordinates (X ^* , Y ^* ). Furthermore, by specifying the coordinates (U ^* , V ^* ) of the blood vessel information coordinate system corresponding to the coordinates (X ^* , Y ^* ), the blood vessel depth U ^* and oxygen saturation V for a predetermined pixel in the blood vessel region. ^* Is required.

When the blood vessel depth U ^* and the oxygen saturation V ^* are obtained, the color information corresponding to the blood vessel depth U ^* is specified based on the color tables 63a to 63c selected by the console 23. Further, based on the color tables 64a to 64c selected by the console 23, the color information corresponding to the oxygen saturation V ^* is specified. The specified color information is stored in a RAM (not shown) in the processor device 12.

When the color information is stored in the RAM, the blood vessel depth U ^* and the oxygen saturation V ^* are obtained for all the pixels in the blood vessel region by the above-described procedure, and the blood vessel depth U ^* and the oxygen saturation are obtained. The color information corresponding to the degree V ^* is specified.

  When the blood vessel depth and the oxygen saturation and the color information corresponding to them are obtained for all the pixels in the blood vessel region, the blood vessel depth image generation unit 63 reads wideband image data from the frame memory 56, and the wideband image data is obtained. By reflecting color information stored in the RAM on the image data, blood vessel depth image data is generated. The oxygen saturation image generation unit 64 generates oxygen saturation image data in the same manner as the blood vessel depth image. The generated blood vessel depth image data and oxygen saturation image data are stored in the frame memory 56 again.

  Then, the display control circuit 58 reads the broadband image data, the blood vessel depth image data, and the oxygen saturation image data from the frame memory 56, and based on these read image data, as shown in FIG. The blood vessel depth image 73 and the oxygen saturation image 74 are displayed on the monitor 14. On the monitor 14, three images of the broadband image 72, the blood vessel depth image 73, and the oxygen saturation image 74 are simultaneously displayed in parallel.

  In the blood vessel depth image 73, the blood vessel images 75 to 77 are pseudo-colored according to the blood vessel depth. Red (R) is added to the blood vessel image 76 of the middle layer blood vessel in the blood vessel image 75 of the surface blood vessel. Is colored green (G), and the blood vessel image 77 of deep blood vessels is colored cyan (Cy). On the other hand, in the oxygen saturation image 74, as in the blood vessel depth image 73, cyan (Cy) is used for the blood vessel image 80 indicating low oxygen saturation, and magenta (M) is used for the blood vessel image 81 indicating medium oxygen saturation. ), The blood vessel image 82 showing high oxygen saturation is colored red (R).

  In the first embodiment, two color information representing each of the blood vessel depth and the oxygen saturation are described separately in the blood vessel depth image 73 and the oxygen saturation image 74. Thus, two pieces of color information may be reflected in one image. For example, as shown in FIG. 15, among the blood vessel images 75 to 77 in the blood vessel depth image 73, the blood vessel images 76 and 77 have color information (for example, a hue ring between two colors) or light and shade as they are. On the other hand, for the blood vessel image 75 in the designated region 92, color information indicating the degree of oxygen saturation (for example, a hue circle between two colors), shading or the like is reflected instead of color information indicating the blood vessel depth. Thereby, two color information can be displayed in one image.

  The designated area 92 is displayed so that it can be distinguished from other areas by changing the background color or displaying a frame line, and a color bar 92a corresponding to the oxygen saturation is displayed at the upper left. Has been. The designation region 92 can be designated at an arbitrary position in the blood vessel depth image 73 by operating the console 23, for example. Thereby, in one blood vessel depth image 73, the oxygen saturation can be confirmed for the blood vessel of the portion designated on the console 23, and the blood vessel depth can be confirmed for the blood vessels other than the designated portion. it can. The designated area is not limited to being designated at an arbitrary position in the image, but may be provided at a fixed position set in advance.

  Further, in the blood vessel depth image 73, instead of displaying the oxygen saturation color information in the designated area 92, as shown in FIG. 16, the blood vessels in the designated area 125 designated in the broadband light image 72 Depending on the size of the depth, the surface blood vessel image 126, the middle blood vessel image 127, and the deep blood vessel image 128 are enlarged and displayed in three stages, and the blood vessels in the images 126, 127, and 128 are oxygenated. Reflect color information corresponding to the degree of saturation. At that time, the image 72a in the body cavity and the blood vessel images 126 to 128 are displayed in separate areas. In each blood vessel image 126-128, the broken line indicates low oxygen saturation, and the solid line indicates high oxygen saturation. Similarly, in accordance with the magnitude of the oxygen saturation, it is enlarged and displayed in three stages of a low oxygen saturation image, a medium oxygen saturation image, and a high oxygen saturation image, and blood vessels in each image are displayed. In contrast, color information corresponding to the blood vessel depth may be reflected. Each blood vessel image includes a specific value of the blood vessel depth, an average value of oxygen saturation of blood vessels in the blood vessel image, a blood vessel area of low oxygen saturation, a blood vessel area of high oxygen saturation, etc. Character information may be displayed.

  15 and 16, the position of the designated region 92 in the blood vessel depth image 73 is designated by the console 23. However, as shown in FIG. A predetermined range of oxygen saturation may be input from the console 23, and a frame 135 may be automatically attached to the blood vessel having the input fixed value or a predetermined range of oxygen saturation. In the upper left of the frame 135, a numerical value 135a indicating the oxygen saturation (StO2 (Saturated Oxygen)) of the blood vessel therein is displayed. The constant value or the constant range of the oxygen saturation is input by the console 23.

  In FIG. 17, a frame 135 is attached to a blood vessel having a certain value or a certain range of oxygen saturation in the blood vessel depth image 73. However, as shown in FIG. In addition to being a constant value or a certain range, the frame 140 may be automatically attached to blood vessels whose blood vessel depth is a constant value or a certain range. In the upper left of the frame 140, numerical values 140a indicating the oxygen saturation (StO2 (Saturated Oxygen)) and the blood vessel depth (D (Depth)) of the blood vessel therein are displayed.

  In FIGS. 17 and 18, the frames 135 and 140 are attached to the blood vessel itself in the image in the body cavity. Instead, for example, as shown in FIG. 19, other than the image 143 in the body cavity. A frame 145 may be displayed on the part. In the frame 145, blood vessels whose oxygen saturation is greater than or equal to a certain value or in a certain range are displayed, and a numerical value 145a indicating the oxygen saturation (StO2 (Saturated Oxygen)) of the blood vessels in the frame 145 is displayed on the upper left. Has been. On the other hand, a circular frame 146 indicating the approximate position of the blood vessel displayed in the frame 145 is displayed on the image 143 in the body cavity. By displaying this round frame 146 in the image 143 in the body cavity, the correspondence between the blood vessels in the frame 145 and the blood vessels in the image 143 in the body cavity can be known. In FIG. 19, a frame is displayed in a portion other than the image in the body cavity on the blood vessel depth image. Similarly, a frame is displayed in a portion other than the image in the body cavity on the oxygen saturation image. You may let them.

  In the broadband optical image, two designated areas may be provided, a designated area in which the color information of the blood vessel depth is reflected and a designated area in which the color information of the oxygen saturation is reflected.

  In the second embodiment, as shown in FIG. 20, the blood vessel image generation unit 57 of the electronic endoscope system 10 replaces the blood vessel depth image generation unit 63 and the oxygen saturation image generation unit 64 with the blood vessel depth and A color information specifying unit 95 that specifies color information corresponding to both oxygen saturations and a blood vessel depth-oxygen saturation image generating unit 97 are provided.

The color information specifying unit 95 includes a stomach color table 95a, a duodenum color table 95b, and a small intestine color table 95c. In each of the color tables 95a to 95c, as shown in FIG. 21, by assigning a hue ring 96 to a UV coordinate system including a U axis indicating the blood vessel depth and a V axis indicating the oxygen saturation, the blood vessel depth is obtained. In addition, oxygen saturation and color information are stored in association with each other. The hue ring 96 is represented by a hue H that is colored in the circumferential direction and a saturation St that is colored in the radial direction. The color information specifying unit 95 is a hue corresponding to the blood vessel depth U ^* and the oxygen saturation V ^* calculated by the blood vessel depth-oxygen saturation calculating unit from the color tables 95a to 95c suitable for the current observation site. Specify H ^* and saturation St ^* .

  The blood vessel depth-oxygen saturation image generation unit 97, when color information including hue and saturation is specified for all the pixels in the blood vessel region, wideband image data read from the frame memory 56. Reflect against. Thereby, broadband image data reflecting both the blood vessel depth and the oxygen saturation is generated. Based on this broadband image data, the display control circuit 58 displays a broadband image 72 as shown in FIG. In the wideband image 72, each blood vessel image 96 colored according to the blood vessel depth and the oxygen saturation is displayed. In the broadband image 72, a color bar 72a to which a hue circle is assigned to the UV coordinate system is displayed on the upper right side of the screen.

  In the third embodiment of the present invention, color information of two colors of color information corresponding to the blood vessel depth and color information corresponding to the oxygen saturation is reflected on one blood vessel in the image. As shown in FIG. 23, in the blood vessel 100, the both ends 100a of the blood vessel 100 centered on the tube axis are represented by color information corresponding to the blood vessel depth, while the central portion 100b of the blood vessel 100 corresponds to the oxygen saturation. Represents color information. The image reflecting the color information may be a broadband image or a monochrome image. Here, the color information includes a two-color hue ring (similar to the first embodiment, a two-color hue ring from R to Cy for blood vessel depth, and two colors from Cy to R for oxygen saturation). It may be expressed by an intercolor hue ring), or may be a gradation between two colors or light and shade.

  In the fourth embodiment of the present invention, as shown in FIG. 24, a predetermined blood vessel image 102 is designated from the broadband image 72, and the blood vessel depth (D (Depth)) and oxygen saturation are designated for the designated blood vessel image 102. (StO2 (Saturated Oxygen)) is displayed as character information. The blood vessel image is designated by operating the console 23. In addition to displaying with text information, a vector with the blood vessel depth as a length and oxygen saturation as an angle may be displayed.

  In the fifth embodiment of the present invention, color information of oxygen saturation is reflected only on a blood vessel having a specific depth. For example, in FIG. 25, the blood vessel image 105 of the superficial blood vessel is specified from the broadband image 72, and the color information corresponding to the oxygen saturation is reflected only on the specified blood vessel image 105 of the superficial blood vessel. The color information is represented by a hue ring from Cy to R, and is represented by Cy when the oxygen saturation is low, and R when the oxygen saturation is high. In the broadband image 72, a color bar 72b indicating a color circle from Cy to R is displayed. Although the color information of the oxygen saturation is reflected on the blood vessel image of the surface blood vessel, it may be reflected on the blood vessel image of the middle blood vessel or the blood vessel image of the deep blood vessel instead.

  In the fifth embodiment, the blood vessel image 105 of the superficial blood vessel is specified from the broadband image 72. Instead, the blood vessel image of the superficial blood vessel is specified from the blood vessel depth image, and the blood vessel image of the specified superficial blood vessel is specified. The color information of the oxygen saturation may be reflected on.

  Furthermore, in the fifth embodiment, the contrast of the blood vessel images 106 and 107 other than the blood vessel image 105 having a specific depth that reflects the color information may be suppressed so that the portion of the blood vessel image 105 is conspicuous. Good.

  In the sixth embodiment of the present invention, the thickness of each blood vessel in the broadband light image 72 is specified, and among the blood vessels whose thickness is specified, a blood vessel having a certain thickness or a certain range of thicknesses. The color information corresponding to the oxygen saturation is reflected. Here, in order to specify the thickness of each blood vessel in the broadband optical image 72, in the electronic endoscope system of the sixth embodiment, a blood vessel thickness calculation unit (not shown) is provided in the blood vessel image generation unit 57. Is provided. For example, in FIG. 26, the blood vessel thickness calculation unit specifies that the blood vessel 150 is thin, the blood vessel 151 is a standard thickness, and the blood vessel 152 is thick. The color information of the oxygen saturation is reflected only on the thick blood vessel 152 among these blood vessels. The color information is the same as that of the fifth embodiment, and is represented by Cy when the oxygen saturation is low, and R when the oxygen saturation is high. In the broadband light image 72, the oxygen saturation and color information are displayed. A color bar 72b indicating the correspondence relationship is displayed. In FIG. 26, the color information of oxygen saturation is reflected on a thick blood vessel, but the color information of oxygen saturation may be reflected on a thin blood vessel and a blood vessel of standard thickness. In addition, it is not color information that reflects the oxygen saturation, but may be one-color shading information. In addition, for each blood vessel in the broadband light image, three of the blood vessel thickness, the blood vessel depth, and the oxygen saturation may be reflected.

  In the seventh embodiment of the present invention, the distribution of blood vessel density representing the density of blood vessels in the body cavity is obtained from the broadband optical image 72 as shown in FIG. After that, an area 155 where the blood vessel density is a constant value or a certain range is specified, and the color information of the oxygen saturation is reflected on the blood vessels in the specific area 155. In the electronic endoscope system of the seventh embodiment, a blood vessel density calculation unit (not shown) is provided in the blood vessel image generation unit 57 in order to specify the blood vessel density in the broadband optical image 72. The color information is the same as in the fifth embodiment, and the oxygen saturation may be reflected by not only the color information but also by one-color shading information. In addition, for each blood vessel in the broadband optical image, the blood vessel density, the blood vessel depth, and the oxygen saturation may be reflected.

  In the eighth embodiment of the present invention, as shown in FIG. 28, when fluorescence is emitted from the tumor affected part 160 by administration of a fluorescent agent, the intensity distribution of fluorescence is obtained from the broadband light image 72. Then, an area 160a where the light intensity is a constant value or a certain range is specified, and the color information of the oxygen saturation is reflected on the blood vessels in the specific area 160a. In the electronic endoscope system of the eighth embodiment, a fluorescence intensity calculation unit (not shown) is provided in the blood vessel image generation unit 57 in order to specify the fluorescence intensity in the broadband light image 72. The color information is the same as in the fifth embodiment, and the oxygen saturation may be reflected by not only the color information but also by one-color shading information. Further, for each blood vessel in the broadband light image, three of fluorescence intensity, blood vessel depth, and oxygen saturation may be reflected.

  In the ninth embodiment of the present invention, the blood concentration (hemoglobin index) of each blood vessel 165, 166, 167 is obtained from the broadband optical image 72 as shown in FIG. After that, the color information of the oxygen saturation is reflected on the blood vessel 167 whose blood concentration is constant or in a certain range. In the electronic endoscope system of the ninth embodiment, a blood concentration calculation unit (not shown) is provided in the blood vessel image generation unit 57 in order to specify the blood concentration in the broadband light image 72. The color information is the same as in the fifth embodiment, and the oxygen saturation may be reflected by not only the color information but also by one-color shading information. In addition, for each blood vessel in the broadband light image, three of blood concentration, blood vessel depth, and oxygen saturation may be reflected.

  In the present invention, the shape of the blood vessel such as the number of branches of the blood vessel is specified from the broadband optical image 72 or the like, and the specified shape of the blood vessel is a predetermined shape (for example, the number of branches of the blood vessel is a certain value or more). If so, the color information of the oxygen saturation may be reflected on the blood vessel having the predetermined shape. In the electronic endoscope system of this embodiment, a blood vessel shape calculation unit (not shown) is provided in the blood vessel image generation unit 57 in order to specify the blood vessel density in the broadband optical image 72. The color information is the same as in the fifth embodiment, and the oxygen saturation may be reflected by not only the color information but also by one-color shading information. In addition, for each blood vessel in the broadband optical image, the blood vessel shape, the blood vessel depth, and the oxygen saturation may be reflected.

  In each of the above embodiments, a total of three frames of imaging signals are obtained for each irradiation of the first to third narrowband lights N1 to N3. Instead, first, the third narrowband light N3 is first transmitted into the body cavity. The first narrow-band light N1 and the second narrow-band light N2 are combined to irradiate the image, and then the first narrow-band light N1 and the second narrow-band light N2 are combined. The first to third narrowband image data may be generated by separating the luminance values of the third narrowband lights N1 to N3, respectively. Alternatively, the first narrowband light N1 may be irradiated first, and then the combined narrowband light of the second narrowband light N2 and the third narrowband light N3 may be irradiated.

  By generating the image data in this way, the number of frames of the imaging signal is reduced to 2 as compared to the first embodiment in which the imaging signal of 3 frames is required to generate the first to third narrowband image data. Yes. Since the blood vessel depth and the oxygen saturation are obtained using the luminance ratio of the pixels at the same position between the first to third narrowband image data, the body movement and insertion portion of the subject is smaller when the number of frames is smaller. It is possible to prevent the positional deviation of the pixel due to movement of

  When the first to third narrowband image data is generated from the imaging signals of a total of two frames, the first to third narrowband light sources 33 to 35 are switched as follows. Under the normal light image mode, the first to third narrow-band light sources 33 to 35 are turned off. When the setting is changed from the normal light image mode to the special light image mode, the third narrowband light source 35 is switched on by the light source switching unit 37, and the third narrowband light N3 is irradiated into the body cavity. Imaging of the subject tissue is performed. When the imaging is completed, a light source switching instruction is given from the controller 59, the third narrow-band light source 35 is turned off, and both the first and second narrow-band light sources 33 and 34 are turned on. Then, imaging is performed in a state where the combined narrow band light composed of the first narrow band light N1 and the second narrow band light N2 is irradiated into the body cavity. When the imaging is completed, both the first and second narrowband light sources 33 and 34 are switched off.

The CCD 44 outputs an imaging signal as follows. First, since the third narrowband light N3 irradiated in the body cavity transmits only B pixels, an imaging signal B1 having only a luminance value L3 based on the third narrowband light N3 is obtained. In the case of the combined narrowband light irradiated after the third narrowband light N3, the first narrowband light N1 passes through the B pixel, while the second narrowband light N2 passes through both the B pixel and the G pixel. . Therefore, the imaging signal B2 including the luminance value L1 based on the first narrowband light N1 and the luminance value L2 based on the second narrowband light N2, and the imaging signal G2 having only the luminance value L2 are obtained. Therefore, the following imaging signal is sent from the CCD 44 to the DSP 55 of the processor device.
Imaging signal B1 = luminance value L3
Imaging signal B2 = luminance value L1 + luminance value L2
Imaging signal G2 = luminance value L2

  The DSP 55 generates first to third narrowband image data based on the imaging signal B1, the imaging signal B2, and the imaging signal G2. Since the imaging signal B1 has only the luminance value L3, the third narrowband image data is obtained from the imaging signal B1. Similarly, since the imaging signal G2 has only the luminance value L2, second narrowband image data can be obtained from the imaging signal G2. On the other hand, the first narrowband image data is obtained by calculating B2− (constant) × G2 and separating the luminance value L2 from the imaging signal B2. Note that (constant) is determined by the intensity ratio of the first and second narrowband light. The obtained first to third narrowband image data is stored in the frame memory 56.

  Further, in each of the above embodiments, instead of the color CCD 44, only the first narrowband pixel and the second narrowband light N2 provided with a filter that transmits only the first narrowband light N1 out of the broadband light BB are used. Even if a CCD in which three types of pixels are arranged, a second narrowband pixel provided with a filter for transmission and a third narrowband pixel provided with a filter that transmits only the third narrowband light N3 is used. Good. By using such a CCD, it is possible to acquire blood vessel information of both blood vessel depth and oxygen saturation from one frame of an imaging signal obtained by irradiating broadband light BB. As described above, various methods can be considered for obtaining the blood vessel depth and the oxygen saturation, but any method other than the above method may be used as long as both the blood vessel depth and the oxygen saturation can be obtained.

  In the above embodiment, the first to third narrowband light sources are used to generate the first to third narrowband lights N1 to N3. However, the first to third narrowband light sources are not installed, and FIG. In the electronic endoscope system 200 as shown, in addition to the broadband light source 30, a rotary filter provided with a filter that transmits light used in the normal light image mode and the special light image mode out of the broadband light BB from the broadband light source 30 230 may be used to irradiate the broadband light BB and the first to third narrowband lights N1 to N3. The rotary filter 230 is provided between the broadband light source 30 and the condenser lens 39, and rotates at a constant speed around the rotation shaft 230a. The rotary filter 130 is movable in two stages in the radial direction by a filter switching unit 231 attached to the rotating shaft 230a.

  As shown in FIG. 31, the rotary filter 230 includes a first area 232 that transmits light used in the normal light image mode in the broadband light BB from the broadband light source 30, and a blood vessel information acquisition process in the broadband light BB. A second area 233 that transmits light to be used is provided. Therefore, when switching modes and processing, the filter switching unit 231 moves the rotary filter 230 in the radial direction so that the area corresponding to the mode to be switched is positioned on the optical path of the broadband light BB.

  The first area 232 is provided with a broadband light transmission filter 235 that transmits the broadband light BB as it is. The second area 233 includes a broadband light transmission filter 235, a first narrowband light transmission filter 236 that transmits only the first narrowband light N1 out of the broadband light BB, and a second light that transmits only the second narrowband light. Two narrow-band light transmission filters 237 and a third narrow-band light transmission filter 238 that transmits only the third narrow-band light N3 are provided along the circumferential direction in this order.

  In the first to fifth embodiments, when the broadband optical image is generated, the broadband light BB is directly irradiated into the body cavity, and the broadband light BB reflected in the body cavity is captured by the color CCD. A broadband optical image is generated based on a broadband imaging signal (simultaneous method). However, RGB light of three colors is time-divided and irradiated into a body cavity, and each color of light reflected in the body cavity is reflected by a monochrome CCD. A broadband optical image may be generated based on three color imaging signals obtained by imaging (frame sequential method).

  When imaging by this frame sequential method, the electronic endoscope system 125 shown in FIG. 30 uses a rotary filter 250 as shown in FIG. 32 instead of the rotary filter 230 as shown in FIG. The rotary filter 250 includes the BGR three color filters 251, 252, and 253 that are continuously provided along the circumferential direction in the same manner as the first area 270 for the normal light image mode and the first area 270. The three color filters 251, 252 and 253 are continuously provided along the circumferential direction, and the first to third narrowband light transmission filters 254 to 256 are continuously provided following the color filter 253. And a second area 271 for the special light image mode.

  In the normal light image mode, the filter switching unit 231 sets the first area 270 for the normal light image mode of the rotary filter 250 on the optical path of the broadband light source 30. Then, the rotary filter 250 is rotated so that the B color filter 251, the G color filter 252, and the R color filter 253 are sequentially positioned on the optical path of the broadband light BB. By the rotation of the rotary filter 250, blue, green, and red light are sequentially irradiated into the body cavity.

  Each time the light of each color is irradiated, imaging is performed with a monochrome CCD, so that imaging signals of three colors of a blue imaging signal, a green imaging signal, and a red imaging signal are obtained. A broadband optical image is generated from the image signals of these three colors. Note that a blue image signal, a green image signal, and a red image signal obtained by the frame sequential method image each time light is irradiated, and therefore a time difference occurs between the signals. Therefore, when the color of the light irradiated into the body cavity is switched, if the subject's body movement or the movement of the insertion part of the endoscope occurs, the generated broadband optical image may be misaligned. is there. On the other hand, the wideband image obtained by the simultaneous method is generated based on the blue image pickup signal, the green image pickup signal, and the red image pickup signal acquired simultaneously by the color CCD.

  Furthermore, in the special light image mode, the second area 271 for the special light image mode of the rotary filter 250 is set on the optical path of the broadband light source 30 by the filter switching unit 231. The B color filter 251, the G color filter 252, the R color filter 253, the first narrowband light transmission filter 254, the second narrowband light transmission filter 255, and the third narrowband light transmission filter 256. Rotate the rotary filter 250 so that are sequentially located on the optical path of the broadband light BB. The rotation of the rotary filter 250 sequentially irradiates the body cavity with blue, green, and red light, and after the red light irradiation, the first narrowband light N1, the second narrowband light N2, and the third light. Narrow band light N3 is irradiated in order.

  Then, by imaging with a monochrome CCD every time each light is irradiated, an imaging signal of three colors of a blue imaging signal, a green imaging signal, and a red imaging signal is obtained, and the first to third narrowband imaging is performed. A signal is obtained. As in the normal light image mode, a broadband light image is generated from the obtained three-color imaging signals.

  In the field sequential method, a rotary filter 258 shown in FIG. 33 may be used instead of the rotary filter 150 shown in FIG. In the rotary filter 258, the first area 280 for the normal light image mode is the same as the first area 270 of the rotary filter 250, but the second area 281 for the special light image mode is the second area of the rotary filter 250. 271 and the filter arrangement are different.

  In the second area 281 of the rotary filter 258, a first narrow-band light transmission filter 254 is provided between the B color filter 251 and the G color filter 252, and the G color filter 252 and the R color filter. A second narrow-band light transmission filter 255 is provided between the N-color filter 253 and a third narrow-band light transmission filter 256 between the R-color filter 253 and the B-color filter 251. Therefore, when the optical path of the broadband light source 30 is set on the second area 281 of the rotary filter 258, the rotary filter 258 rotates, so that B color light → first narrow band light N1 → G color light. → Second narrowband light N2 → R-color light → third narrowband light N3 is irradiated into the body cavity in this order.

  FIG. 34 shows the reading order of the imaging signals when the rotary filter 250 shown in FIG. 32 is used in the special light image mode and the reading order of the imaging signals when the rotary filter 258 shown in FIG. 33 is used. ing. As shown in FIG. 34A, by rotating the rotary filter 250 shown in FIG. 32, B-color light, G-color light, R-color light, first narrow-band light N1, second narrow-band light N2, and third narrow-band light. The light N3 is emitted every one frame period in this order. Then, for each light irradiation, a blue imaging signal, a green imaging signal, a red imaging signal, a first narrowband imaging signal, a second narrowband imaging signal, and a third narrowband imaging signal are read in this order.

  On the other hand, as shown in FIG. 34B, by rotating the rotary filter 258 shown in FIG. 33, B color light, first narrow band light N1, G color light, second narrow band light N2, R color light, third color light, Narrow band light N3 is irradiated in this order every frame period. Then, for each light irradiation, a blue imaging signal, a first narrowband imaging signal, a green imaging signal, a second narrowband imaging signal, a red imaging signal, and a third narrowband imaging signal are sequentially read in this order.

  As described above, there is a difference in the reading order of the imaging signals between the case where the rotary filter 250 is used and the case where the rotary filter 258 is used. In view of this difference, the signal read rate can be sufficiently ensured when the rotary filter 258 is used to irradiate each light and read out the imaging signal.

  Further, in place of the primary color CCD composed of B pixels, G pixels, and R pixels as shown in the above embodiment, complementary color colors composed of C (cyan) pixels, M (magenta) pixels, and Y (yellow) pixels. A broadband optical image may be generated by imaging with a CCD. In this complementary color CCD, as shown in FIG. 35, a C color filter having a spectral transmittance 160 in the C pixel, and an M color filter having a spectral transmittance 161 in the M pixel are provided in the Y pixel. A color filter having a spectral transmittance 162 is provided. In addition to the C pixel, M pixel, and Y pixel, a G pixel provided with a G color filter having the spectral transmittance 53 shown in FIG. 3 may be added to the pixels of the complementary color CCD.

  In the present invention, at least two narrowband signals used for simultaneous acquisition of blood vessel depth and oxygen saturation are required, and at least one of the two narrowband signals has a center wavelength of 450 nm. Any narrowband signal corresponding to the following narrowband light may be used. In the above-described embodiment, a color CCD is used as the imaging unit. However, in the special light image mode, when the processing for reducing the number of frames as in the second and third embodiments is not performed, the monochrome CCD is used. A CCD may be used. For example, as in the first embodiment, when the first to third narrowband lights N1 to N3 are sequentially irradiated and imaged for each frame, a monochrome CCD may be used.

  The present invention can be applied not only to an insertion type electronic endoscope having an insertion portion or the like, but also to a capsule type electronic endoscope in which an imaging element such as a CCD is incorporated in a capsule.

[Appendix]
According to the embodiment of the present invention described in detail above, the following configuration can be obtained.

[Appendix 1]
Irradiating means for irradiating a subject tissue including a blood vessel in a body cavity with illumination light including a wavelength region of 450 nm or less;
An electronic endoscope having an image pickup device that picks up an image of the subject tissue and outputs an image pickup signal representing a luminance of reflected light reflected by the subject tissue from the illumination light;
First and second narrowband signals included in the imaging signal, corresponding to first and second narrowband lights having different wavelength regions and having at least one central wavelength of 450 nm or less. And a first narrowband signal acquisition means for acquiring a second narrowband signal;
Blood vessel information obtaining means for obtaining blood vessel information including both blood vessel depth and oxygen saturation based on the first and second narrowband signals;
An electronic endoscope system comprising display control means for controlling blood vessel information of both blood vessel depth and oxygen saturation to be displayed simultaneously on a monitor.

DESCRIPTION OF SYMBOLS 10 Electronic endoscope system 14 Monitor 30 Broadband light source 33-35 1st-3rd narrowband light source 44 CCD
55 DSP
57 Blood vessel image generation unit 58 Display control circuit 60 Luminance ratio calculation unit 61 Correlation storage unit 63 Blood vessel depth image generation units 63a to 63c, 64a to 64c, 95a to 95c Color table for stomach, duodenum, and small intestine 64 Oxygen saturation Degree image generation unit 73 blood vessel depth image 74 oxygen saturation image 95 color information identification unit 96 hue ring

Claims (35)

Irradiating means for irradiating a subject tissue including a blood vessel in a body cavity with illumination light including a wavelength region of 450 nm or less;
An electronic endoscope having an image pickup device that picks up an image of the subject tissue and outputs an image pickup signal representing a luminance of reflected light reflected by the subject tissue from the illumination light;
First to third narrowband signals included in the imaging signal, corresponding to first to third narrowband lights having different wavelength regions and having at least one central wavelength of 450 nm or less. Narrowband signal acquisition means for acquiring first to third narrowband signals;
Blood vessel information acquisition means for obtaining blood vessel information including both the blood vessel depth and oxygen saturation based on the first to third narrowband signals;
An electronic endoscope system comprising display control means for controlling blood vessel information of both blood vessel depth and oxygen saturation to be displayed simultaneously on a monitor.   2. The electronic endoscope system according to claim 1, further comprising a blood vessel image generating unit that generates a display image reflecting the blood vessel information.   The electronic endoscope system according to claim 2, wherein the blood vessel image generation unit reflects blood vessel information as color information or grayscale information of one color. The blood vessel image generation means includes a blood vessel depth image in which a blood vessel having a blood vessel depth of a certain level or more is emphasized over other blood vessels, and an oxygen saturation level in which a blood vessel having a certain degree of oxygen saturation is emphasized over other blood vessels Generate two images of the image,
3. The electronic endoscope system according to claim 2, wherein the display control means displays the two display images side by side on a monitor screen. A first color table for storing blood vessel depth and color information in association with each other;
A second color table for storing oxygen saturation and color information in association with each other;
Using the first color table, the color information corresponding to the blood vessel depth determined by the blood vessel information acquisition means is specified,
Using the second color table, the color information corresponding to the oxygen saturation obtained by the blood vessel information acquisition means is specified,
4. The electronic endoscope system according to claim 3, wherein the specified color information of the two colors is reflected in the display image. The blood vessel image generation means generates two images, a blood vessel depth image reflecting color information corresponding to the blood vessel depth and an oxygen saturation image reflecting color information corresponding to the oxygen saturation,
6. The electronic endoscope system according to claim 5, wherein the display control means displays the two display images side by side on a monitor screen.   6. The blood vessel image generation means generates one display image in which one of blood vessel depth and oxygen saturation is reflected in a part of the region and the other is reflected in the remaining region. The electronic endoscope system described.   8. The electronic endoscope system according to claim 7, wherein the partial area can be designated at an arbitrary position in the display image.   8. The electronic endoscope according to claim 7, wherein the partial region is automatically attached to a blood vessel in which either one of the blood vessel depth and the oxygen saturation is a constant value or a predetermined range. Mirror system.   8. The partial region is automatically attached to a blood vessel whose blood vessel depth is a constant value or a predetermined range and whose oxygen saturation is a constant value or a predetermined range. The electronic endoscope system described.   The display image includes a body cavity image that displays the entire body cavity and a blood vessel display image that is displayed in a region different from the body cavity image and displays blood vessels in a predetermined region in the body cavity. 6. The electronic endoscope system according to claim 5, wherein a blood vessel depth or oxygen saturation is reflected in at least one of the blood vessel display images.   12. The electronic endoscope system according to claim 11, wherein in the blood vessel display image, blood vessels in a predetermined region in the body cavity are displayed in different images at a certain depth.   13. The electronic endoscope system according to claim 12, wherein the blood vessel display image includes a surface blood vessel image, a middle blood vessel image, and a deep blood vessel image.   The electronic endoscope system according to claim 12 or 13, wherein the blood vessel display image displays an enlarged blood vessel in a predetermined region in the body cavity. The blood vessel image generation means includes
Color information corresponding to the blood vessel depth is reflected in a part of one blood vessel in the display image, and color information corresponding to the oxygen saturation is reflected in another part of the same blood vessel. The electronic endoscope system according to claim 5.   16. In the one blood vessel, one of the two color information of the blood vessel depth and oxygen saturation is reflected at both ends thereof with the tube axis as the center, and the other is reflected at the central portion. The electronic endoscope system described. The blood vessel image generation means includes
6. The electronic endoscope system according to claim 5, wherein color information corresponding to the oxygen saturation is reflected only on a blood vessel having a specific depth in the display image.   18. The electronic endoscope system according to claim 17, wherein the blood vessel image generation unit suppresses contrast of a portion other than the blood vessel having the specific depth.   19. The electronic endoscope according to claim 5, wherein the first and second color tables have one of a hue circle between two colors and a gradation between two colors as color information. Mirror system.   In the first color table, the blood vessel depth is divided into a plurality of stages, and a different color is assigned to each stage. In the second color table, the oxygen saturation is divided into a plurality of stages and is different for each stage. The electronic endoscope system according to any one of claims 5 to 18, wherein a color is assigned.   21. The electronic endoscope system according to claim 5, wherein each of the first and second color tables includes a plurality of tables that can be switched according to an observation site.   In the display image, a color bar indicating the correspondence between the blood vessel depth and the color assigned in the first color table, and the correspondence between the oxygen saturation and the color assigned in the second color table. The electronic endoscope system according to any one of claims 5 to 21, wherein at least one of color bars indicating the relationship is displayed. The blood vessel information acquisition means obtains a blood vessel depth and oxygen saturation, and obtains a blood vessel thickness based on the imaging signal,
The blood vessel in which at least one of blood vessel thickness or blood vessel depth and oxygen saturation is reflected as color information or light and shade information of one color is displayed in the display image. Electronic endoscope system. The blood vessel information acquisition means obtains the blood vessel depth and oxygen saturation, obtains the blood vessel density based on the imaging signal,
The blood vessel in which at least one of blood vessel density or blood vessel depth and oxygen saturation is reflected as color information or light and shade information of one color is displayed in the display image. Electronic endoscope system. The blood vessel information acquisition means obtains the intensity of fluorescence based on the imaging signal when the blood vessel depth and oxygen saturation are obtained, and when fluorescence is emitted from the tumor affected part by administration of the fluorescent agent,
The blood vessel in which at least one of fluorescence intensity or blood vessel depth and oxygen saturation is reflected as color information or light and shade information of one color is displayed in the display image. Electronic endoscope system. The blood vessel information acquisition means obtains the blood concentration based on the imaging signal while obtaining the blood vessel depth and oxygen saturation,
The blood vessel in which at least one of blood concentration or blood vessel depth and oxygen saturation is reflected as color information or light and shade information of one color is displayed in the display image. Electronic endoscope system. The blood vessel information acquisition means obtains the blood vessel depth and oxygen saturation, obtains the shape of the blood vessel based on the imaging signal,
The blood vessel in which at least one of the shape or depth of the blood vessel and the oxygen saturation is reflected as color information or light and shade information of one color is displayed in the display image. Electronic endoscope system. A third color table that associates and stores color information of one color for each combination of blood vessel depth and oxygen saturation;
A color information specifying unit for specifying color information corresponding to the combination of the blood vessel depth and the oxygen saturation obtained by the blood vessel information acquisition means using the third color table;
The blood vessel image generation means includes
4. The electronic endoscope system according to claim 3, wherein the color information specified by the color information specifying unit is reflected on an image obtained based on the imaging signal.   The third color table associates color information of one color for each combination of blood vessel depth and oxygen saturation by assigning a color wheel to a blood vessel information coordinate system indicating the blood vessel depth and oxygen saturation. The electronic endoscope system according to claim 28, wherein the electronic endoscope system is stored.   30. The electronic endoscope system according to claim 28 or 29, wherein the third color table has a plurality of tables that can be switched according to an observation site. The image sensor is a black and white image sensor,
The irradiation means can irradiate light of three colors of R color, G color, and B color in a time division manner, and can irradiate the first and second narrowband light in a time division manner,
It has frame sequential normal light image generation means for generating a normal light image based on an imaging signal obtained by irradiating light of three colors of R, G, and B in a time-sharing manner. The electronic endoscope system according to any one of claims 1 to 30, wherein the electronic endoscope system is characterized in that: The image pickup device has three pixels of R, G, and B pixels provided with three color filters of R, G, and B,
The irradiation means can irradiate white broadband light including a wavelength region from a blue region to a red region to which each pixel of R, G, and B is sensitive,
31. The electron according to claim 1, further comprising a simultaneous normal light image generating unit that generates a normal light image based on an imaging signal obtained by irradiating the broadband light. Endoscope system. The image pickup device has three pixels of C, M, and Y pixels provided with three color filters of C, M, and Y.
The irradiation means can irradiate white broadband light including a wavelength region from a blue region to a red region to which each pixel of C, M, and Y is sensitive,
31. The electron according to claim 1, further comprising a simultaneous normal light image generating unit that generates a normal light image based on an imaging signal obtained by irradiating the broadband light. Endoscope system. An imaging signal obtained by irradiating illumination light including a wavelength region of 450 nm or less and imaging a subject tissue including blood vessels in a body cavity with an imaging device of an electronic endoscope, and reflected light reflected by the illumination light Receiving means for receiving an imaging signal representing the brightness of the electronic endoscope from the electronic endoscope;
First to third narrowband signals included in the imaging signal, corresponding to first to third narrowband lights having different wavelength regions and having at least one central wavelength of 450 nm or less. A narrowband signal acquisition means for acquiring a third narrowband signal;
Blood vessel information acquisition means for obtaining blood vessel information including both the blood vessel depth and oxygen saturation based on the first to third narrowband signals;
A processor device for an electronic endoscope, comprising: display control means for controlling so that blood vessel information of both blood vessel depth and oxygen saturation is simultaneously displayed on a monitor. The illumination means emits illumination light including a wavelength region of 450 nm or less;
An imaging element that captures an image of a subject tissue including a blood vessel in a body cavity to obtain an imaging signal representing the brightness of reflected light reflected by the illumination light from the subject tissue;
The first to third narrowband signal acquisition means are the first to third narrowband signals included in the imaging signal, have different wavelength regions, and at least one of the center wavelengths is 450 nm or less. Obtaining first to third narrowband signals corresponding to narrowband light;
Blood vessel information acquisition means , based on the first to third narrowband signals, to obtain blood vessel information including both blood vessel depth and oxygen saturation;
Display control means, the electronic endoscope system The operating method which comprises a step of controlling so that both vessel information of the blood vessel depth and oxygen saturation level are simultaneously displayed on the monitor.

Images