JP2012085916A - Electronic endoscope system, processor device of the same, and method of supersensitizing fluoroscopic image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the picture quality of a fluoroscopic image at low cost.SOLUTION: White light and excitation light are applied into a body cavity. An electronic endoscope obtains a white light image by using a CCD to image the white light reflected inside the body cavity, and obtains an autofluorescence image by using the CCD to image autofluorescence that is emitted from a living tissue within the body cavity by application of the excitation light. The movement of the subject of observation within the body cavity is detected based on the white light image. The autofluorescence image is subjected to frame addition and binning process. In that case, the number of frames added and the number of binning are varied depending on the movement of the subject of observation.

Description

  The present invention relates to an electronic endoscope system for observing autofluorescence emitted from a living tissue in a body cavity, a processor device for the electronic endoscope system, and a method for increasing the sensitivity of a fluorescent image.

  In the medical field in recent years, many diagnoses and treatments using an electronic endoscope system have been performed. In an electronic endoscope system, white light having a wavelength ranging from a blue band to a red band is irradiated in a body cavity, and light reflected in the body cavity is imaged by an imaging element such as a CCD. Then, an image obtained by imaging is displayed on the monitor. Thereby, since the image in a body cavity can be confirmed in real time, a diagnosis etc. can be performed reliably.

  Although the entire subject tissue can be roughly grasped from the captured image obtained by irradiating with white light, the microscopic blood vessels, deep blood vessels, pit patterns (gland opening structure), uneven structures such as depressions and bumps, etc. The subject tissue may be difficult to observe clearly. Since there is a possibility that a lesioned part is hidden in such a subject tissue, there is a demand for reliably grasping a fine blood vessel, a depression, a bulge, and the like from a captured image.

  For example, as a method for observing neoplastic lesions such as cancer, as shown in Patent Document 1, excitation light limited to a specific wavelength is irradiated into a body cavity, and from the endogenous fluorescent substance in living tissue by the excitation light. AFI (Auto Fluorescence Imaging) is known in which auto-fluorescence emitted is imaged by an image sensor. In AFI, taking advantage of the property that the intensity of autofluorescence emitted from a lesion having a neoplastic lesion is weaker than the intensity of autofluorescence emitted from a normal area where there is no tumorous lesion, The part and normal part are displayed in different colors. Therefore, this AFI makes it possible to observe even a lesion that is almost indistinguishable from a normal part.

JP 2009-34224 A

  However, since the amount of autofluorescence emitted from the living tissue is very weak, the autofluorescence image obtained by imaging the autofluorescence may not perform useful image diagnosis as it is. Therefore, in order to effectively use the autofluorescence image for diagnosis or the like, it is necessary to improve the image quality of the autofluorescence image by some method. For example, in Patent Document 1, a total of two excitation lights are irradiated from two illumination windows provided at the distal end portion of an electronic endoscope to increase the intensity of the autofluorescence, thereby improving the image quality of the autofluorescence image. ing. However, it is costly to provide two illumination windows at the distal end of the electronic endoscope.

  The present invention has been made in view of the above problems, and an electronic endoscope system and a processor device for an electronic endoscope system that can improve the image quality of fluorescent images such as autofluorescent images without incurring costs. And it aims at providing the sensitivity enhancement method of a fluorescence image.

  In order to achieve the above object, an electronic endoscope system of the present invention includes a light source device that emits excitation light for exciting fluorescence from a living tissue in a body cavity, and a body cavity in which fluorescence is emitted by irradiation of excitation light. An electronic endoscope that acquires an endoscopic image including a fluorescent image of the image by imaging with an image sensor, a motion detection unit that detects a motion of an observation target in a body cavity from the endoscopic image, and a frame on the fluorescent image Sensitivity enhancement processing means for performing addition and binning processing, and sensitivity enhancement processing control means for performing control to change the frame addition and binning processing in accordance with the motion of the observation target are provided.

  The frame addition is a process of adding image data of fluorescent images of a plurality of frames to generate a high-quality fluorescent image of one frame, and the binning process collects a plurality of adjacent pixels in the fluorescent image. Software binning is preferably performed in which the luminance value of each pixel group is obtained by reconfiguring the pixel group and adding the luminance values of the pixels in each pixel group.

  The high-sensitivity processing means includes a frame addition number indicating the number of frames of a fluorescent image used for generating a high-quality fluorescent image of one frame and a binning number indicating the number of pixels in a pixel group reconstructed by software binning. Are preferably changed according to the amount of movement of the observation target. The high-sensitivity processing means preferably increases the frame addition number with the passage of time when there is no movement in the observation target. The high sensitivity processing means preferably changes the binning process according to the size of the observation target. It is preferable to provide size input means for inputting the size of the observation object. In the initial state where imaging of the fluorescent image is started, it is preferable to determine the number of frames added and the number of binning according to the fluorescence intensity of the fluorescent image.

  The frame addition is processing to add image data of fluorescent images of a plurality of frames to form a fluorescent image of one frame, and the binning processing is performed for each pixel group composed of a plurality of adjacent pixels in the image sensor. Hardware binning that controls the image sensor so as to output the image signal is preferable. The light source device is capable of emitting white light having a wavelength ranging from a blue band to a red band toward a body cavity, and the motion detection unit is a white light obtained by imaging the body cavity irradiated with white light. It is preferable to detect the motion of the observation target from the image.

  The fluorescent image is preferably an autofluorescent image obtained by AFI. The fluorescence image is preferably a drug fluorescence image obtained by PDD or near infrared fluorescence observation.

  The present invention irradiates a body cavity with illumination light including excitation light for exciting fluorescence from a living tissue in a body cavity, and connects an electron connected to an electronic endoscope that images return light from the body cavity with an imaging device. In a processor device of an endoscope system, an endoscope image including a fluorescence image in a body cavity in which fluorescence is emitted is received from the electronic endoscope, and an endoscope image received by the receiving means Motion detection means for detecting the movement of the observation target in the body cavity, high sensitivity means for applying frame addition and binning processing to the fluorescent image, and control for changing the frame addition and binning processing according to the movement of the observation target And a high sensitivity processing control means.

  The present invention provides a high-sensitivity fluorescent image that enhances the sensitivity of a fluorescent image in a body cavity that is emitted by excitation light irradiation among endoscopic images in a body cavity imaged by an imaging device in an electronic endoscope. In the sensitivity enhancement method, the movement of the observation target in the body cavity is detected from the endoscopic image, frame addition and binning processing are performed on the fluorescence image, and the frame addition and binning processing are changed according to the movement of the observation target. It is characterized by performing control.

  According to the present invention, it is possible to perform high-sensitivity processing without cost by performing frame addition and binning processing of existing functions in an electronic endoscope system on a fluorescent image. In addition, since the frame addition and binning process are changed according to the movement of the observation target in the body cavity, there is no blurring of the image of the observation target when the sensitivity of the fluorescent image is increased. Also, the resolution is not reduced.

It is the schematic which shows the electronic endoscope system of 1st Embodiment. It is a block diagram which shows the electric constitution in the electronic endoscope system of 1st Embodiment. It is a graph which shows the spectral intensity distribution of excitation light, autofluorescence, and white light. It is a perspective view which shows the front-end | tip part of the electronic endoscope of 1st Embodiment with which the overtube and the hood were mounted | worn. It is explanatory drawing for demonstrating the irradiation range of white light. It is explanatory drawing for demonstrating a rotary shutter when it exists in a white light irradiation period. It is explanatory drawing for demonstrating a rotary shutter when it exists in a white light shielding period. It is explanatory drawing for demonstrating the method to control the light quantity of excitation light according to the light quantity of white light. It is explanatory drawing for demonstrating the irradiation range of excitation light. It is sectional drawing of the 1st light projection unit for excitation light irradiation. It is explanatory drawing for demonstrating the imaging control of CCD in normal light observation mode. It is explanatory drawing for demonstrating the imaging control of CCD in autofluorescence observation mode. It is a block diagram which shows the processing flow in a signal processing part. It is a graph in which initial setting values are plotted. It is explanatory drawing for demonstrating the high sensitivity process in case a still state continues. It is explanatory drawing for demonstrating the high sensitivity process in the time of a still state different from FIG. It is explanatory drawing for demonstrating the high sensitivity process in the case of changing from the still state to the motion state which a motion produces in an observation object. It is a table | surface which shows LUT which memorize | stored the correspondence of a motion amount, the number of frame addition, and the number of binning. It is explanatory drawing for demonstrating the high sensitivity process by frame addition. It is a top view of the rotary filter used for irradiation of the field sequential light of RGB. It is a block diagram which shows the electrical constitution of the electronic endoscope system provided with the light projection unit which irradiates white light with blue excitation light and a fluorescent member. It is sectional drawing of the light projection unit for white light irradiation. It is a perspective view of a probe for excitation light, a hood, and a tip part.

  As shown in FIG. 1, an electronic endoscope system 10 according to the present invention includes an electronic endoscope 11 that captures an image of a body cavity of a subject using an image sensor such as a CCD, and an insertion unit 20 of the electronic endoscope 11. , A hood 14 attached to the distal end portion 24a of the insertion portion 20, a processor device 15 for generating an image of a subject tissue in the body cavity based on a signal obtained by imaging, and a body cavity A white light source device 16 for supplying white light to be irradiated to the light source, an excitation light source device 17 for supplying excitation light for exciting autofluorescence from the living tissue, and a monitor 18 for displaying an image in the body cavity. It has.

  The electronic endoscope 11 includes a flexible insertion portion 20 to be inserted into a body cavity, an operation portion 21 provided at a proximal end portion of the insertion portion, an operation portion 21, a processor device 15, and a white light source device. 16 is provided with a universal cord 23 that connects the two. A bending portion 24 is formed at the distal end of the insertion portion 20 by connecting a plurality of bending pieces. The bending portion 24 bends in the up / down / left / right directions by the operation of the angle knob 26 of the operation portion.

  At the distal end of the bending portion 24, a distal end portion 24a incorporating an optical system for in-vivo imaging is provided. The distal end portion 24 a is directed in a desired direction within the body cavity by the bending operation of the bending portion 24. The distal end portion 24a has two first and second illumination windows 57 and 59 (see FIG. 4) that emit white light and excitation light, and an observation window 62 (see FIG. 4) that receives white light and autofluorescence from inside the body cavity. 4), an air supply / water supply nozzle 63 (see FIG. 4) for blowing water or air toward the observation window, and a forceps outlet 64 (see FIG. 4) serving as an outlet of the treatment instrument inserted into the forceps channel in the insertion portion 20. 4).

  The operation unit 21 switches the observation mode to either a normal light observation mode for observing the body cavity using white light or an autofluorescence observation mode for observing autofluorescence emitted from the living tissue using excitation light. A button 28 is provided. Switching information by the observation mode switching button 28 is transmitted to the controller 113 (see FIG. 2) of the processor device.

  Here, when the normal light observation mode is set, a white light image obtained by imaging the white light reflected in the body cavity is displayed on the monitor 18 and the auto fluorescence observation mode is set. The monitor 18 displays an autofluorescence image obtained by imaging autofluorescence or a composite image obtained by synthesizing a white light image and an autofluorescence image.

  A connector 30 is attached to the end of the universal cord 23 on the processor device 15 and white light source device 16 side. The connector 30 is a composite type connector composed of a communication connector and a light source connector, and the electronic endoscope 11 is detachably connected to the processor device 15 and the white light source device 16 through the connector 30. The

  A hood 14 including an excitation light cut filter 32 is attached to the distal end portion 24 a of the electronic endoscope 11. The excitation light cut filter 32 covers or covers the observation window 62 (see FIG. 4) provided at the distal end portion 24a, thereby cutting or reducing the light in the wavelength band of the excitation light out of the light before entering the observation window 62. . The excitation light with very high energy is cut in front of the observation window 62 so that the excitation light does not enter the CCD 100 (see FIG. 2) provided on the back side of the observation window 62. It is possible to prevent halation in which the screen becomes white due to the charge saturation.

  The overtube 13 is provided in the tube main body 35, the endoscope main passage 35, the endoscope insertion conduit 37 through which the insertion portion 29 of the electronic endoscope 11 is inserted, and the endoscope insertion conduit 37. Two first and second optical fibers 38 and 39 that are provided around and guide light of excitation light from the light source device 17 of excitation light are provided.

  The endoscope insertion conduit 37 includes a proximal end opening 37 a serving as an insertion port of the insertion unit 20 of the electronic endoscope and a distal end opening 37 b serving as an outlet of the insertion unit 20. Therefore, when the insertion portion 20 is inserted through the endoscope insertion conduit 37, the distal end portion 24a of the electronic endoscope and the hood 14 attached to the distal end portion 24a are exposed from the distal end side opening 37b. When inserting the insertion portion 20 of the electronic endoscope into the body cavity, the insertion portion 20 is inserted through the overtube 13. Further, first and second light projecting units 41 and 42 for irradiating the body cavity with excitation light from the first and second optical fibers 38 and 39 are fixed to the outer peripheral surface of the hood 14. The first and second optical fibers 38 and 39 and the first and second light projecting units 41 and 42 are optically coupled by a connector or the like.

  As shown in FIG. 2, a white light source device 16, a white light source 45, an aperture adjustment mechanism 46, a white light control unit 47, a rotary shutter 48, a position detection unit 49, and a rotation control unit 50 are provided. The white light source 45 is always turned on to emit white light when the power source of the white light source device 16 is on. White light is broadband light having a wavelength ranging from a blue band to a red band, and has a wavelength band of 400 nm to 700 nm as shown in FIG. 3, for example. As the white light source 45, for example, a xenon lamp, a halogen lamp, an LED (light emitting diode), a fluorescent light emitting element lamp, or an LD (laser diode) is used. White light emitted from the white light source 45 is collected by the lens 53. The light condensed by the lens 53 is incident on the first and second light guides 55 and 56 via the aperture adjustment mechanism 46.

  The first and second light guides 55 and 56 are constituted by large-diameter optical fibers or the like. The incident side end portions of the first and second light guides 55 and 56 are connected to the light source device 16 for white light. On the other hand, as shown in FIG. 4, the emission side end of the first light guide 55 is directed to the first illumination window 57 of the distal end portion 24 a of the electronic endoscope 11, and the emission side end of the second light guide 55. Is directed to the second illumination window 59 of the tip 24a. White light is emitted from the first and second illumination windows 57 and 59 toward the body cavity.

  The first illumination window 57 and the second illumination window 59 are provided at symmetrical positions with respect to the excitation light cut filter 32 (or the observation window 62) provided in the hood 14. Further, as shown in FIG. 5, the irradiation range WL1 of white light emitted from the first illumination window 57 and the irradiation range WL2 of white light emitted from the second illumination window 59 substantially overlap each other. Therefore, when the distal end portion 24a is directed to the observation target T, the observation target T substantially enters the overlapping region WLR of the irradiation ranges WL1 and WL2. Thereby, it is possible to irradiate the observation target T with white light sufficiently and without uneven illumination.

  The hood 14 covers only the observation window 62 in the distal end portion 24a, and the other portions are exposed from the opening portion 14a into the body cavity. Therefore, the hood 14 does not prevent the white light from being emitted from the first and second illumination windows 57 and 59. Further, air or water from the air / water supply nozzle 63 can be blown to the excitation light cut filter 32 of the hood. Furthermore, the treatment tool can be protruded from the forceps outlet 64 into the body cavity.

  As shown in FIG. 2, the aperture adjustment mechanism 46 is disposed between the lens 53 and the rotary shutter 48 and adjusts the amount of white light emitted from the white light source 45. The aperture adjusting mechanism 46 is composed of, for example, a plurality of aperture blades that vary the aperture diameter, and a motor that moves the aperture blades. The aperture amount of the aperture adjustment mechanism (that is, the amount of white light) is controlled by the white light control unit 47 via the driver 47a. The white light control unit 47 controls the aperture amount (that is, the amount of white light) based on the white light image obtained by the signal processing in the processor device 15.

  As shown in FIGS. 6A and 6B, the rotary shutter 48 has a disk shape and has a sector-shaped cutout part. Of the rotary shutter 48, the cutout portion is a light transmission portion 48a that transmits white light, and the remaining portion is a light shielding portion 48b that blocks white light. The rotary shutter 48 is connected to a rotation shaft 70 a of a motor 70 that is arranged in parallel with the optical axis of the white light source 45. When the rotary shutter 48 is rotated by driving the motor 70, the light transmitting portions 48a and the light shielding portions 48b are alternately positioned on the optical path P of the white light source.

  Which of the light transmission part 48a and the light shielding part 48b is located on the optical path P is detected by a position detection part 49 constituted by a photosensor or the like. Here, in FIGS. 2 and 6A and 6B, the position detection unit is arranged in the vicinity of the outer periphery of the rotary shutter, but the arrangement position may be other than that, for example, inside the rotary shutter.

  As shown in FIG. 6A, while the light transmitting portion 48a is positioned on the optical path P, white light is incident on the first and second light guides 55 and 56, so that white light is irradiated into the body cavity. This period is a white light irradiation period below. On the other hand, as shown in FIG. 6B, while the light shielding portion 48b is positioned on the optical path P, white light is not incident on the first and second light guides 55 and 56, so that the white light is shielded in the body cavity. It becomes. This period is hereinafter referred to as a white light blocking period. The position detection unit 49 appropriately transmits information on whether the white light irradiation period or the white light blocking period is present to the excitation light control unit 75 in the excitation light source device and the controller 113 of the processor device.

  The white light irradiation period and the white light blocking period differ depending on the observation mode, and each period in the autofluorescence observation mode is set to twice that in the normal light observation mode. Therefore, the rotation control unit 50 shown in FIG. 2 performs rotation control so that the rotation speed of the rotary shutter 48 is half of the rotation speed in the normal light observation mode in the auto fluorescence observation mode. The rotation control unit 50 controls the rotation speed of the rotary shutter 48 via a driver 50 a connected to the motor 70.

  As shown in FIG. 2, the excitation light source device 17 includes first and second laser light sources 72 and 73 and an excitation light control unit 75. The first and second laser light sources 72 and 73 are composed of light emitting diodes and the like, and emit excitation light having a wavelength of 405 ± 10 nm as shown in FIG. By irradiating the body cavity with excitation light having such a wavelength range, autofluorescence having a wavelength of 420 nm to 650 nm is emitted from the endogenous fluorescent substance in the living tissue.

  When the first and second laser light sources 72 and 73 are set to the autofluorescence observation mode, excitation light is always emitted. Thereby, autofluorescence is always emitted from the living tissue. As shown in FIG. 3, the excitation light returning to the distal end portion 24a of the electronic endoscope is cut by an excitation light cut filter, and the amount of autofluorescence is weaker than that of white light. Therefore, even if a white light image is acquired in a state where not only white light but also excitation light and autofluorescence exist in the body cavity, the excitation light and autofluorescence do not affect the acquired white light image at all.

  The excitation light control unit 75 controls the amount of excitation light of the first and second laser light sources 72 and 73 via the drivers 75a and 75b. The excitation light control unit 75 is connected to the white light control unit 47 and controls the amount of excitation light according to the white light amount control by the white light control unit 47. The amount of excitation light is controlled so that the white light and the excitation light have a predetermined correlation, for example, the ratio of the amount of excitation light to the amount of white light is maintained at 1/10. Change the amount of light.

  Even if the amount of white light is changed in this way, the amount of excitation light is automatically changed by the excitation light control unit following this, so the white light image and the autofluorescence image The exposure balance can always be maintained in an appropriate state. In addition, the light amount control of the excitation light is not performed in conjunction with the light amount control of the white light, but when the white light irradiation period is switched to the white light shielding period as shown in FIG. The excitation light may be controlled to have a predetermined correlation.

  The excitation light emitted from the first laser light source 72 enters the first optical fiber 38 of the overtube. The excitation light emitted from the other second laser light source 73 is incident on the second optical fiber 39 of the overtube. As shown in FIG. 4, the excitation light EL in the first optical fiber 38 is emitted from the first light projection unit 41 of the hood 14, and the excitation light EL in the second optical fiber is emitted from the second light projection of the hood 14. The light is emitted from the unit 42.

  The first and second light projecting units 41 and 42 are respectively symmetrical with respect to the excitation light cut filter 32 (or the observation window 62) of the hood 14 similarly to the first and second illumination windows 57 and 59 of the distal end portion 24a. In the position. Further, as shown in FIG. 8, the irradiation range EL1 of the excitation light emitted from the first light projecting unit 41 and the irradiation range EL2 of the excitation light emitted from the second light projection unit 42 substantially overlap (overlapping). Area ELR). Further, the overlapping area ELR is included in the overlapping area WLR in which the two white light irradiation ranges overlap.

  Since the irradiation ranges EL1 and EL2 are as described above, the observation target T almost enters the overlapping area ELR of the irradiation ranges EL1 and EL2 when the distal end portion 24a is directed to the observation target T. Thereby, it is possible to irradiate the observation target T with excitation light sufficiently and without illumination unevenness. Therefore, for example, when the entire observation target T is a normal part, autofluorescence with substantially the same intensity is emitted from the entire area of the observation target. Furthermore, since the overlap area ELR where the two excitation light irradiation ranges overlap is included in the overlap area WLR of the two white light irradiation ranges, the amount of white light and excitation light in the entire observation target T The ratio is kept constant.

  As shown in FIG. 9, the first light projecting unit 41 includes a light diffusing member 90, a cylindrical sleeve member 91 that covers the outer periphery of the light diffusing member, and a protective glass 92 that seals one end of the sleeve member 91. And a ferrule 93 that is inserted into the sleeve member and holds the first optical fiber 38. In addition, a flexible sleeve 95 that covers the outer side of the outer sheath is inserted between the sleeve member 91 and the first optical fiber 38 that is covered with the outer shell and extends from the rear end side of the ferrule 93. Since the second light projecting unit is the same as the first light projecting unit, description thereof is omitted.

  The light diffusing member 90 is made of a translucent resin material that diffuses excitation light from the first optical fiber 38. In addition to the translucent resin material, for example, translucent ceramics or glass can be used. The light diffusing member 90 has a configuration in which a light diffusing layer in which fine irregularities and particles (fillers, etc.) having different refractive indexes are mixed on the surface, intermediate layer, or the like, or a configuration using a translucent material. It is good. Thereby, the light quantity of the excitation light emitted from the light diffusing member 90 is made uniform by the polarization action and diffusion action of light. Therefore, by appropriately changing the material and amount of the light diffusing member, the irradiation range and the light amount of the excitation light can be adjusted in the first light projecting unit. In addition, the irradiation range and light quantity of the light within a 1st light projection unit can be adjusted also by changing a lens and protective glass suitably other than a light-diffusion member.

  As shown in FIG. 2, the electronic endoscope 11 includes a CCD 100, an analog processing circuit 104 (AFE: Analog Front End), and an imaging control unit 106. The CCD 100 receives the light transmitted through the excitation light cut filter 32, the observation window 62, and the condenser lens 102 by the imaging surface 100a. The CCD 100 photoelectrically converts the light received by the imaging surface 100a to accumulate signal charges, and reads the accumulated signal charges as imaging signals. The read imaging signal is sent to the AFE 104.

  The CCD 100 is a color CCD, and three pixels of R, G, and B pixels provided with R, G, and B color filters are arranged on the imaging surface 100a. Here, since the wavelength range of white light extends from the blue band to the red band, when white light is incident on the CCD imaging surface, all of the R pixel, G pixel, and B pixel are sensitive. Accordingly, the image pickup signal obtained when receiving white light includes three types of image pickup signal output from the R pixel, image pickup signal output from the G pixel, and image pickup signal output from the B pixel.

  On the other hand, autofluorescence has a main wavelength region in the green band, and a part extends to the blue band or the red band. For this reason, when the autofluorescence enters the imaging surface 100a of the CCD, the G pixel is surely sensitive to autofluorescence. Therefore, the imaging signal obtained at the time of receiving autofluorescence includes the imaging signal output from the G pixel.

  The AFE 104 includes a correlated double sampling circuit (CDS) and an automatic gain control circuit (AGC). The CDS performs correlated double sampling processing on the image pickup signal from the CCD to remove noise generated by driving the CCD 100. The AGC amplifies the imaging signal from which noise has been removed by CDS.

  The imaging control unit 106 performs imaging control of the CCD 44. In accordance with the imaging control of the imaging control unit 106, an imaging signal is output from the AFE 45 at a predetermined frame rate. The imaging control unit 106 is connected to the controller 113 in the processor device 15, and the imaging control unit 106 changes the control method as appropriate depending on the observation mode recognized by the controller 113 at the time of imaging.

  Here, as shown in FIG. 10A, when the normal light observation mode is set, a step of photoelectrically converting white light and accumulating signal charges is performed during the white light irradiation period. When the white light irradiation period is switched to the white light shielding period, an imaging signal readout pulse is transmitted from the imaging control unit 106 to the CCD 100. When the CCD 100 receives the imaging signal readout pulse, the signal charge accumulated in the CCD 100 is output to the AFE 104 as an imaging signal. Then, when the white light shielding period is switched to the white light irradiation period, a step of photoelectrically converting the white light and accumulating signal charges is performed again. The series of operations described above are repeated while the normal light image mode is set.

  On the other hand, when the autofluorescence observation mode is set, as shown in FIG. 10B, during the white light irradiation period, a step of photoelectrically converting white light and accumulating signal charges is performed. When the white light irradiation period is switched to the white light shielding period, an imaging signal readout pulse is transmitted from the imaging control unit 106 to the CCD 100. When the CCD 100 receives the imaging signal readout pulse, the signal charge accumulated in the CCD 100 is output to the AFE 104 as an imaging signal. Almost simultaneously with this, a step of photoelectrically converting autofluorescence to accumulate signal charges is performed. Although the autofluorescence is weak, it is possible to form an autofluorescence image by making the autofluorescence observation mode twice that of the autofluorescence observation mode, that is, the autofluorescence observation period in the normal light observation mode. Can be reliably received by the CCD 100.

  Then, after a lapse of a fixed time after switching from the white light irradiation period to the white light shielding period, an imaging signal readout pulse is transmitted from the imaging control unit 106 to the CCD 100. In response to this, the signal charge accumulated in the CCD 100 is output to the AFE 104 as an imaging signal. Then, when the white light shielding period is switched to the white light irradiation period, a step of photoelectrically converting the white light and accumulating signal charges is performed again. The above series of operations is repeated while the autofluorescence observation mode is set.

  As shown in FIG. 2, the processor device 15 is electrically connected to the electronic endoscope 11, the white light source device 16, the excitation light source device 17, the monitor 18, a keyboard (not shown), a printer (not shown), and the like. To control the overall operation of the electronic endoscope system 10 in an integrated manner. The processor device 15 includes a signal processing unit 110, a frame memory 112, and a controller 113.

  The signal processing unit 110 performs various processes on the imaging signal output from the AFE 104 of the electronic endoscope 11 by the A / D conversion unit 115, the color tone correction unit 116, and the image processing unit 117, thereby the monitor 18. A video signal that can be displayed is generated. Various images are displayed on the monitor 18 based on the video signal. Note that the color tone correction unit 116 and the image processing unit 117 are configured by, for example, software that performs corresponding processing and a storage device such as an EPROM (rewritable ROM) that stores the software. The digital image data after A / D conversion and the video signal after image processing in the image processing unit are stored in the frame memory 112 temporarily or each time processing is performed.

  The A / D conversion unit 115 converts the imaging signal from the AFE 104 into digital image data. The image data includes a B image obtained from the imaging signal output from the B pixel of the CCD 100, a G image obtained from the imaging signal output from the G pixel, and an R image obtained from the imaging signal output from the R pixel. It is. In addition, the image data after A / D conversion includes image data of a white light image acquired in the normal light observation mode or the autofluorescence observation mode, and image data of an autofluorescence image acquired in the autofluorescence observation mode. .

  The color tone correction unit 116 and the image processing unit 117 perform processing according to the flow shown in FIG. The color tone correction unit 116 supplements the component of the B image that is cut or reduced by the excitation light cut filter 32 in the white light image. As shown in FIG. 3, the electronic endoscope 11 performs imaging through an excitation light cut filter 32 that cuts or attenuates a component of a wavelength band of 415 nm or less, and therefore, among the white light image and the B image of the autofluorescence image Part of the low wavelength side is cut. Therefore, the color correction unit 116 corrects the cut image.

The correction of the B image of the white light image is performed as follows. First, the following correction equations (1) and (2) are obtained before using the endoscope. Here, when the excitation light cut filter is not attached, the B light amount of the white light image is B ′, and when the excitation light cut filter is attached, the B ′ image light amount of the white light image is B. , B and B ′ are expressed by the following equation (1).
B = B ′ × α (1)
Here, α is a light amount cut rate by the excitation light cut filter. Therefore, B ′ can be obtained by the following equation (2).
B ′ = B / α (2)

  As shown in Expression (2), when the relationship between B and B ′ is a linear relationship, the light quantity B of the B image of the white light image obtained when the excitation light cut filter is attached is expressed by a coefficient α. By dividing, the light amount B ′ of the portion cut by the excitation light cut filter is obtained. Then, by replacing the light amount B of the cut portion of the white light B image with the light amount B ′, a white light image similar to the case where the excitation light cut filter is not attached can be obtained.

  When the relationship between B and B ′ is not a linear relationship, the amount of light corresponding to the cut portion of the B image can be increased by, for example, arithmetic processing such as multiplication, addition, and matrix conversion. . Further, the components of the G image and the R image may be reduced by the component corresponding to the cut component of the B image. Furthermore, when some components on the low frequency side of the G image are cut by the excitation light cut filter, it is preferable to perform color tone correction in the same manner as in the case of the B image.

  The image processing unit 117 illustrated in FIG. 2 includes a balance adjustment unit 120, a high sensitivity processing unit 121, and a display gradation processing unit 122. The balance adjustment unit 120 adjusts the balance between the white light image and the autofluorescence image using the calibration data when the autofluorescence observation mode is set. The calibration data is obtained from a white light image and an autofluorescence image captured in advance for a lesion part (an occurrence part of early cancer, etc.) and a normal part of an unspecified subject.

  By performing balance adjustment using the calibration data, for example, the contrast between the lesioned part and the normal part in the white light image is equal to the contrast between the lesioned part and the normal part in the autofluorescence image. For example, when the contrast of the autofluorescence image is 1/5 with respect to the contrast of the white light image, the color tone correction unit 116 adjusts the balance to make the contrast of the autofluorescence image 5 times based on the calibration data. To do. As described above, the balance adjustment is performed with higher accuracy because the light quantity ratio between the white light and the excitation light is kept constant.

  Since the balance between the white light image and the autofluorescence image depends on the characteristics of the CCD or the like, the balance adjustment should be performed at least before shipping the electronic endoscope system to the factory or before using the electronic endoscope system for the first time. It is preferable to carry out once.

  The high sensitivity processing unit 121 increases the sensitivity of the autofluorescence image by performing frame addition and software binning on the autofluorescence image. Frame addition is a process of obtaining image data of high image quality for one frame by adding image data of a plurality of consecutive frames. Software binning is a process of reconstructing a plurality of adjacent pixels as one pixel group in the autofluorescence image and adding the luminance value of the pixel in each pixel group to the luminance value of each pixel group. . The sensitivity enhancement process may be performed not only on the autofluorescence image but also on the white light image.

  In the following description, the number of frames of the autofluorescence image used for generating a high-quality autofluorescence image for one frame in the frame addition is referred to as a frame addition number. Further, the number of pixels in the pixel group reconstructed by software binning is referred to as binning number. Note that the binning number is expressed by multiplying the number of pixels arranged along the vertical direction and the number of pixels arranged along the horizontal direction, for example, 2 × 2.

  Both frame addition and software binning can improve the luminance value in the autofluorescence image, that is, increase the sensitivity. On the other hand, in frame addition, as the number of frame additions increases, the frame rate decreases and the image becomes blurred. In addition, software binning increases with an increase in the number of binning, thereby reducing the resolution of the autofluorescence image.

  Therefore, when performing high sensitivity processing, it is necessary to perform appropriate frame addition and software binning according to the imaging situation in the body cavity. In the present embodiment, first, immediately after switching to the autofluorescence observation mode, initial setting values of the frame addition number and the binning number are determined from the fluorescence intensity of the autofluorescence. The fluorescence intensity is calculated from the autofluorescence image.

  If the calculated fluorescence intensity is large, the need for frame addition and software binning is low, so the initial setting value decreases the number of frame additions and the number of binnings. Accordingly, the initial set value Pa1 at this time is plotted in the lower left part on the graph shown in FIG. On the other hand, if the calculated fluorescence intensity is small, the necessity for frame addition and software binning is high, and therefore the initial setting value increases the number of frame additions and the number of binnings. Therefore, the initial set value Pa2 at this time is plotted in the upper right part on the graph shown in FIG.

  After the initial setting value is determined, the frame addition number and the binning number are changed so that the sensitivity of the autofluorescent image can be increased without blurring the image and without reducing the resolution. Here, the frame addition number and the binning number are changed according to the image size of the observation target and the amount of motion of the observation target. The size of the observation target is acquired from the white light image or the autofluorescence image, or is acquired from the size input unit 125 (see FIG. 2) connected to the processor device 15. Here, if the size of the observation target is large, the number of binning is increased from the initial setting value, and if the size of the observation target is small, the initial setting value is maintained. The size input unit 125 may input a magnification and a distance between the observation target and the tip.

  On the other hand, the movement amount of the observation target is acquired from the white light image. Since the white light image generally has a higher luminance value than the autofluorescence image, it is easier to obtain the amount of movement of the observation target from the white light image. Here, when the amount of motion is “0”, that is, in a stationary state, the number of frame additions is increased from the initial set value as time passes. By increasing the number of frame additions in such a stationary state, the autofluorescence image becomes highly sensitive. On the other hand, when a motion amount occurs, the frame addition number is decreased according to the motion amount. Thereby, occurrence of image blurring of the observation target can be prevented.

  Next, specific examples of processing in the high sensitivity processing unit are as follows: (A) the case where the observation target is not moving and the stationary state continues; and (B) the movement from the stationary state to the observation target after a certain period of time has elapsed. A description will be given separately for the case where the movement state is changed.

  The processing in the case of (A) is performed according to the graphs 130 to 132 in FIG. Each of these graphs 130 to 132 corresponds to the size of the observation target, and is arranged so that the large size of the observation target is located on the right side. Accordingly, among the graphs 130 to 132, the graph 132 corresponds to the largest size, the graph 131 corresponds to the intermediate size, and the graph 132 corresponds to the smallest size. Then, when performing frame addition and software binning, one graph corresponding to the size of the observation target is selected from these graphs 130 to 132.

  In FIG. 13, Pa indicates the frame addition number and the binning number at the initial setting value. Px indicates the number of frame additions and the number of binning during a predetermined time, and this Px moves to the upper right along the graphs 130 to 132 as time elapses. Then, Px reaches a steady value Pb after a certain time has elapsed. If there is no change in the size and movement of the observation target after the lapse of a certain time, the frame addition number and the binning number at the steady value Pb are maintained. The steady value Pb is set so as to increase as the size of the observation target increases. By changing the frame addition number and the binning number according to such graphs 130 to 132, it is possible to ensure appropriate sensitivity according to the size of the observation target, and to increase the frame addition number over time. Can improve image quality.

  In the processing in the case of (A), if the size of the observation target is not large, as shown in graphs 133 to 135 in FIG. 14, the number of added frames is increased while the number of binning is decreased as time passes. May be. In this case, when performing frame addition and software binning, one graph corresponding to the size of the observation target and other conditions is selected from the graphs 133 to 135 shown in FIG. Note that Pa, Pb, and Px shown in FIG. 14 are the same as those in FIG.

  The processing in the case of (B) is performed according to the graphs 136 to 138 in FIG. These graphs 136 to 138 correspond to the size of the observation target, and the arrangement order of these graphs is the same as in the case of FIG. On the other hand, in the graphs 136 to 138 of FIG. 15, in the stationary state, Px indicating the number of frame additions and the number of binning in a predetermined time has already reached the steady value Pb. When the observation object moves, Px moves to the lower right along the graph according to the amount of movement.

  Here, when the amount of movement is small, the amount of movement of Px is small, and when the amount of movement is large, the amount of movement of Px is also large. Then, frame addition and software binning are performed based on the frame addition number and the binning number indicated by Px. Further, the amount of movement of the observation target is detected at regular intervals, and Px is also moved accordingly. Therefore, Px moves on the graphs 136 to 138 to the lower right or upper left depending on the amount of movement of the observation target. As described above, by changing the number of frame addition and the number of binning, it is possible to ensure appropriate sensitivity according to the size of the observation target, and increase or decrease the number of frame addition according to the amount of motion of the observation target. Therefore, it is possible to prevent image blurring from being observed.

  Although the frame addition number and the binning number are changed according to the graphs shown in FIGS. 13 to 15, instead of this, the movement amount of the observation target and the movement amount are used as shown in FIG. 16. The frame addition number and the binning number may be changed according to the LUT 140 storing the frame addition number and the binning number. In the high sensitivity processing unit, the number of binning may be reduced when the observation target includes a large number of high-frequency structures, and the number of binning may be increased when the high-frequency structure is small within the observation target. Further, when the number of binning is increased, high frequency emphasis signal processing may be performed.

  The display gradation processing unit 122 performs display gradation processing for converting a white light image or an autofluorescence image into a video signal that can be displayed on a monitor. This display gradation processing includes γ correction processing and gradation correction processing corresponding to the monitor. In this display gradation processing, when the normal light observation mode is set, among the white light images, the B image is the B channel signal of the video signal, the G image is the G channel signal of the video signal, R An image is assigned to the R channel signal.

  On the other hand, when the auto-fluorescence observation mode is set, the B image of the white light image is assigned to the B channel signal of the video signal, and the R image of the white light image is assigned to the R channel signal of the video signal. The G image is assigned to the G channel signal of the video signal. Thereby, a composite image in which the white light image and the autofluorescence image are combined is obtained. By displaying such a composite image on the monitor 18, the normal part is displayed in green and the lesioned part is displayed in magenta.

  Note that the brightness level of the autofluorescence is lowered due to the fact that the imaging distance is increased in addition to the lesion. Therefore, the image processing unit compares the brightness levels of the G image of the white light image and the G image of the autofluorescence image before displaying the magenta color on the monitor. If both are low as a result of the comparison, it is determined that the brightness level is low because the imaging distance is far and not the lesion, and the display is displayed in green instead of magenta. On the other hand, when the brightness level of the G image of the white light image is high and the brightness level of the autofluorescence image is low, the white light image is determined to be a lesion and displayed in magenta.

  Next, the operation of the present invention will be described. First, the auto fluorescence observation mode is set by the observation mode switching button 28. In the autofluorescence observation mode, white light and excitation light are irradiated into the body cavity during the white light irradiation period, and only the excitation light is irradiated into the body cavity during the white light shielding period. Since the excitation light is irradiated in both the white light irradiation period and the white light shielding period, autofluorescence is always emitted from the living tissue in the body cavity. The electronic endoscope 11 uses the CCD 100 to capture a white light image during the white light irradiation period and an autofluorescence image during the white light shielding period. The imaging signals acquired by these imaging are sent to the processor device 15.

  In the processor device 15, the A / D conversion unit 115 converts the imaging signal into digital image data. After the color tone correction is performed by the color tone correction unit 116 based on the obtained image data, the balance adjustment unit 120 of the image processing unit 117 performs the balance adjustment using the calibration data, and the sensitivity enhancement processing unit 121 increases the sensitivity. The display gradation processing is performed by the display gradation processing unit 122. Through these processes, a composite image obtained by combining the white light image and the autofluorescence image is obtained. Then, this composite image is displayed on the monitor 18.

  Of the image processing unit 117, the high sensitivity processing unit 121 increases the sensitivity of the autofluorescence image by performing frame addition and software binning on the autofluorescence image. When performing frame addition and software binning, first, the fluorescence intensity is detected from the autofluorescence image. Then, according to the fluorescence intensity, initial setting values for the frame addition number and the binning number are determined.

  After the initial setting value is determined, the frame addition number and the binning number are changed so that the sensitivity of the autofluorescent image can be increased without blurring the image and without reducing the resolution. Here, the frame addition number and the binning number are changed according to the image size of the observation target and the amount of motion of the observation target. The image size of the observation target is acquired from a white light image, an autofluorescence image, or acquired from the size input unit 125. On the other hand, the movement amount of the observation target is acquired from the white light image.

  For example, when the image size of the observation target is large, the number of binning is increased from the initial setting value to ensure appropriate sensitivity according to the size of the observation target. On the other hand, when the movement of the observation target is “0”, that is, in a stationary state, the autofluorescence image is made highly sensitive by increasing the number of frames added from the initial setting value as time passes. Then, when movement occurs in the observation target, the occurrence of image blur in the observation target is suppressed by reducing the number of frame additions.

  In the above embodiment, software binning for binning processing is performed on the autofluorescence image sent from the electronic endoscope to the processor device. Instead, the image is captured by the CCD in the electronic endoscope. Sometimes hardware binning for binning processing may be performed. Hardware binning refers to a process of outputting one imaging signal in units of pixel groups composed of a plurality of adjacent pixels in a CCD. Therefore, when the amount of motion of the observation target is small, the number of pixels in the pixel group is reduced, while when the amount of motion is large, the number of pixels in the pixel group is increased.

  In the above embodiment, both the frame addition number and the binning number are changed in accordance with the size of the object to be observed and the amount of motion, but an electronic endoscope that does not include a binning process such as software binning or hardware binning. In the system, only the frame addition number may be changed according to the amount of motion of the observation target. In this case, it is preferable to change the frame addition number according to a graph 142 as shown in FIG. Note that the initial set value Pa is determined based on the fluorescence intensity of the autofluorescence image, as in the above embodiment.

  In the stationary state, as described above, the sensitivity of the autofluorescence image is increased by increasing the number of frame additions from the initial set value Pb as time passes. Then, when the amount of motion changes from a static state to a quasi-static state that is close to “0”, such as immediately after the observation object starts moving, the increase in the number of frame additions is stopped. The number of frame additions at this time is Px. Then, as shown in the graph 143, the frame addition number Px when the frame addition number in the quasi-stationary state is changed from the stationary state to the quasi-stationary state is maintained.

  In the quasi-static state, since the amount of motion is almost “0”, even if frame addition is performed with the frame addition number Px, there is no possibility of image blurring. Therefore, even in the quasi-static state, the same high sensitivity as that in the stationary state can be achieved. When the amount of motion increases and the quasi-static state is exited, the frame addition number is decreased according to the amount of motion. Here, as shown in the graph 143, the decrease in the number of frame additions increases as the amount of motion increases.

  In the above embodiment, the body cavity is irradiated with white light as it is, but instead of this, the body cavity may be irradiated with surface sequential light composed of R color light, G color light, and B color light. Good. In order to irradiate the surface sequential light, a rotary filter 220 as shown in FIG. 18 is used instead of the rotary shutter 48 shown in FIGS. 6A and 6B. The rotary filter 220 includes a light shielding unit 221 similar to the light shielding unit 48 b of the rotary shutter 48, an R color filter 223 r that transmits R light among white light from the white light source 45, and the white light source 45. A G color filter 223g that transmits G light in the white light and a B color filter 223b that transmits B light in the white light from the white light source 45 are provided along the circumferential direction. It has been. By rotating the rotary filter 220 around the rotation shaft 220a, R light, G light, and B light are irradiated in this order in the body cavity during the white light irradiation period.

  In the above embodiment, the white light irradiated into the body cavity is generated by the white light source in the white light source device. Instead, as shown in the electronic endoscope system 300 of FIG. White light may be generated by the blue laser light source 304 in the white light source device and the light projecting units 306 and 307 provided in the distal end portion 24a of the electronic endoscope. The blue laser light source 304 emits blue laser light having a center wavelength of 445 nm. The emitted blue laser light is emitted from the light projecting units 306 and 307 toward the inside of the body cavity via the light guides 55 and 56. The blue laser light source 304 is controlled by the blue laser light control unit 305 through the driver 305a.

As shown in FIG. 20, the light projecting unit 306 has the same configuration as the first and second light projecting units 41 and 42 except that a phosphor 310 is provided instead of the light diffusing member. The phosphor 310 absorbs a part of the blue laser light from the light guide 55 and emits green to yellow excitation light (for example, YAG phosphor, BAM (BaMgAl ₁₀ O ₁₇ ), etc.). Phosphor). As a result, green to yellow excitation light that uses blue laser light as excitation light and blue laser light that is transmitted without being absorbed by the phosphor 310 are combined to generate white light. The light projecting unit 307 is also the same as the light projecting unit 306, and a description thereof will be omitted.

  Moreover, in the said embodiment, although excitation light was irradiated from the 1st and 2nd light projection units 41 and 42 adhering to the food | hood 14, instead, as shown in FIG. 21, the forceps channel of the insertion part 20 is used. The excitation light probe 400 inserted through 20a may be protruded from the probe holding portion 403 of the hood 402, and excitation light may be irradiated from the irradiation portion 400a of the excitation light probe 400. The excitation light probe 400 is connected to an excitation light source device 401 having laser light sources 72 and 73 similar to those in the above embodiment.

  The hood 402 is the same as the hood 14 of the above embodiment in that the excitation light cut filter 32 is provided, but the probe holding unit 403 and the openings 405 and 406 for the first and second illumination windows 57 and 59 are provided. It differs from the hood in that it is formed. Therefore, the irradiation unit 400a of the excitation light probe 400 held by the probe holding unit 403 is directed into the body cavity, and the first and second illumination windows 57 and 59 are exposed from the openings 405 and 406. The attachment of the hood 402 does not hinder the irradiation of excitation light or white light.

  Moreover, although the said embodiment demonstrated the case where AFI which observes the autofluorescence emitted from the endogenous fluorescent substance in a biological tissue by irradiation of excitation light was applied to this invention, this invention is PDD using a fluorescent agent. (Photo Dynamic Diagnosis) and near infrared fluorescence observation can also be applied.

  In PDD, the wavelength of fluorescence differs depending on the fluorescent agent administered to the patient. For example, when “photophilin”, “resaphyrin”, or “bisdyne” is administered as a drug, the biological tissue in the body cavity emits fluorescence with a central wavelength of 660 nm by irradiating the biological tissue in the body cavity with excitation light having a central wavelength of 405 nm. It is done. In addition, when “5-ALA (aminoalebmin)” is administered as a drug, the biological tissue in the body cavity is irradiated with excitation light having a central wavelength of 405 nm, and two peaks at wavelengths of 635 nm and 670 nm are emitted from the biological tissue. The fluorescence which has is emitted. On the other hand, in near-infrared fluorescence observation, ICG (Indocyanine Green) is used as a drug. By administering this ICG to a patient and irradiating the living tissue in the body cavity with excitation light of about 800 nm, near-infrared fluorescence having a peak wavelength of 845 nm is emitted from the living tissue.

  The drug fluorescence observed by PDD or near-infrared fluorescence observation as described above has a larger amount of light than autofluorescence observed by AFI, but due to other factors such as insufficient accumulation of the fluorescent drug in the living tissue. There may be a shortage. In such a case, frame addition and binning processing as in the above embodiment are performed on the drug fluorescence image obtained by imaging the drug fluorescence. Then, the frame addition and binning processing are changed according to the movement of the observation target. As a result, the sensitivity of the drug fluorescence image can be increased.

DESCRIPTION OF SYMBOLS 10,300 Electronic endoscope system 11 Electronic endoscope 15 Processor apparatus 16 Light source apparatus 100 of excitation light CCD
106 Imaging control unit 110 Signal processing unit 121 High sensitivity processing unit 125 Size input unit

Claims (13)

A light source device that emits excitation light for exciting fluorescence from biological tissue in a body cavity;
An electronic endoscope for acquiring an endoscopic image including a fluorescent image in a body cavity in which fluorescence is emitted by irradiation of excitation light by imaging with an imaging element;
Movement detecting means for detecting movement of an observation object in a body cavity from the endoscopic image;
High sensitivity processing means for performing frame addition and binning processing on the fluorescent image;
An electronic endoscope system comprising: a high sensitivity processing control unit configured to perform control to change the frame addition and binning processing according to a motion of an observation target. The frame addition is a process of adding image data of a plurality of fluorescent images to generate a high-quality fluorescent image of one frame,
The binning process is a software binning process that reconstructs a group of adjacent pixels in a fluorescent image as a group, and adds the luminance values of the pixels in each pixel group to the luminance value of each pixel group. The electronic endoscope system according to claim 1, wherein the electronic endoscope system is provided.   The high-sensitivity processing means includes a frame addition number indicating the number of frames of a fluorescent image used for generating a high-quality fluorescent image of one frame and a binning number indicating the number of pixels in a pixel group reconstructed by software binning. The electronic endoscope system according to claim 2, wherein the electronic endoscope system is changed according to the amount of movement of the observation target.   4. The electronic endoscope system according to claim 3, wherein the high sensitivity processing means increases the frame addition number with the passage of time when there is no movement in the observation target.   5. The electronic endoscope system according to claim 1, wherein the high-sensitivity processing unit changes binning processing according to a size of an observation target.   6. The electronic endoscope system according to claim 5, further comprising size input means for inputting a size of an observation target.   The electronic endoscope system according to any one of claims 3 to 6, wherein, in an initial state in which imaging of a fluorescent image is started, a frame addition number and a binning number are determined according to the fluorescence intensity of the fluorescent image. . The frame addition is a process of adding image data of a plurality of fluorescent images to form a fluorescent image of one frame,
2. The electronic binning according to claim 1, wherein the binning process is hardware binning that controls the image sensor so that one image signal is output in units of pixel groups including a plurality of adjacent pixels in the image sensor. 3. Endoscope system. The light source device is capable of emitting white light having a wavelength ranging from a blue band to a red band toward a body cavity,
The electronic endoscope according to any one of claims 1 to 7, wherein the motion detection unit performs motion detection of an observation target from a white light image obtained by imaging in a body cavity irradiated with white light. system.   The electronic endoscope system according to claim 1, wherein the fluorescence image is an autofluorescence image obtained by AFI.   The electronic endoscope system according to any one of claims 1 to 9, wherein the fluorescence image is a drug fluorescence image obtained by PDD or near-infrared fluorescence observation. An electronic endoscope system connected to an electronic endoscope that irradiates the body cavity with illumination light including excitation light for exciting fluorescence from a living tissue in the body cavity and images the return light from the body cavity with an imaging device. In the processor unit of
Receiving means for receiving, from the electronic endoscope, an endoscope image including a fluorescence image in a body cavity in which fluorescence is emitted;
A motion detecting means for detecting a motion of an observation target in a body cavity from an endoscopic image received by the receiving means;
High sensitivity means for performing frame addition and binning processing on the fluorescent image;
A processor device for an electronic endoscope system, comprising: a high-sensitivity processing control unit configured to perform control to change the frame addition and binning processing according to a motion of an observation target. In a method for increasing the sensitivity of a fluorescent image, the sensitivity of a fluorescent image in a body cavity that is emitted by irradiation of excitation light among endoscopic images in a body cavity captured by an imaging device in an electronic endoscope ,
Detecting the movement of the observation object in the body cavity from the endoscopic image,
Applying frame addition and binning to the fluorescent image,
A method for increasing the sensitivity of a fluorescent image, characterized in that control for changing the frame addition and binning processing according to the movement of an observation target is performed.

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