JP4459771B2 - Processor for electronic endoscope - Google Patents

Description

  The present invention relates to an electronic endoscope processor to which an electronic endoscope for observing the inside of a body cavity is connected.

  As is well known, biological tissue is excited to emit fluorescence when irradiated with light of a specific wavelength. In addition, an abnormal living tissue in which a lesion such as a tumor or cancer has occurred emits weaker fluorescence than a normal living tissue. This reaction phenomenon can also be caused by living tissue below the body cavity wall. In recent years, an electronic endoscope system has been developed that uses this reaction phenomenon to detect abnormalities that occur in a living tissue under a body cavity wall.

  Many of these types of electronic endoscope systems are configured to operate in a special operation state for detecting the above-described abnormality, apart from the conventional operation state in which white light is used as illumination light. . In a conventional operation state, this electronic endoscope system irradiates white light into the body cavity from the tip of the insertion portion of the electronic endoscope, and uses a color image inside the body cavity illuminated with white light as a normal observation image. Display on the display device. On the other hand, in a special operating state, this electronic endoscope system emits excitation light for exciting biological tissue from the distal end of the insertion portion into the body cavity, and fluoresces a color image of the body cavity wall that emits fluorescence. An observation image is displayed on the display device.

  Since fluorescent light mainly containing green is strongly emitted from living tissue, the above-mentioned fluorescence observation image shows a shadow due to the depth of the body cavity and the unevenness of the surface of the body cavity wall as a change in the contrast between green and black. However, when a diseased tissue is present in a part of such a body cavity wall, there is a high possibility that a dark part different from the dark part due to the shadow appears in the fluorescence observation image. Therefore, the surgeon can recognize abnormalities that cannot be recognized through the normal observation image displayed on the display device in the conventional operation state by observing this dark portion in the fluorescence observation image.

Patent Documents 1 and 2 disclose techniques for operating the electronic endoscope system in the special operation state described above.
JP 2004-000505 A Special Table 2002-535645

  By the way, among those engaged in endoscopic surgery, the above-mentioned electronic endoscopic procedures such as collection of biopsy tissue using forceps and excision of lesion tissue using a scissors are described. Some people want to do this through fluorescence observation images with an endoscope system.

  However, if there is bleeding from the surgical site where sampling or excision is performed and the body cavity wall is covered with blood, hemoglobin, which is the main component of blood, does not emit fluorescence even when irradiated with excitation light, and the body cavity wall Since the excitation light does not reach the lower living tissue, the fluorescence is not emitted from the wall of the body cavity, so that the fluorescence observation image becomes dark. If there is such a problem, if there is bleeding in the operation through the fluorescence observation image, the fluorescence observation image will be darkened as soon as it becomes impossible to operate the forceps and scissors, and in addition, the hemostasis operation cannot be performed. As a result, there is a risk that the subject may suffer time damage.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to allow a procedure to be safely continued even when bleeding occurs from a treatment site in a procedure through a fluorescence observation image.

  A processor for an electronic endoscope according to a first aspect invented to solve the above-described problem is an electronic endoscope having an insertion portion that is inserted into a body cavity of a subject. An electronic endoscope processor to which image data (image signal) obtained by imaging a subject facing the distal end of an insertion portion is input, and is passed through the insertion portion and is attached to the distal end of the insertion portion. A light source unit that selectively introduces white light for illuminating the subject and excitation light for exciting a living tissue toward an incident end surface of a light guide on which an emission end surface is disposed, and the light source unit includes the light During the period in which the white light is introduced to the incident end face of the guide, image data input from the electronic endoscope is acquired as normal observation image data, and the light source unit is applied to the excitation end face of the light guide. In the introduced period, an image data acquisition unit that acquires image data input from the electronic endoscope as fluorescence observation image data, and a predetermined process is performed on the image data acquired by the image data acquisition unit to externally When the excitation light is continuously incident on the incident end face of the light guide, the image processing unit that outputs to the apparatus, and the light source unit, at least one color component of the fluorescence observation image data acquired by the image data acquisition unit A determination unit that determines whether or not a luminance value selected from each luminance value that constitutes a value falls below a predetermined threshold, and only during a period in which the determination unit determines that the luminance value is below the threshold The white light is incident at least periodically on the incident end surface of the light guide with respect to the light source unit, and the white light is illuminated with respect to the image processing unit. In that it comprises a temporary processing control unit to output to the external device the image data for displaying an image including an image of the subject that is characterized.

  With this configuration, when the excitation light is continuously incident on the incident end face of the light guide, the luminance value selected from the luminance values constituting at least one color component of the fluorescence observation image data is When the fluorescence observation image indicated by the fluorescence observation image data becomes dark as a whole below the predetermined threshold, an image including the image of the subject illuminated with white light is displayed on the display device. Then, when the fluorescence observation image becomes brighter as a whole, the excitation light again enters the incident end face of the light guide again. For this reason, even if the fluorescence observation image temporarily becomes dark due to bleeding from the treatment site, the surgeon can safely continue the treatment through the subject image illuminated with white light.

  In addition, the electronic endoscope processor of the second aspect invented to solve the above-described problem is detachably mounted with an electronic endoscope having an insertion portion that is inserted into a body cavity of a subject. An electronic endoscope processor to which image data (image symbol) obtained by imaging a subject facing the distal end of the insertion unit is input, and is passed through the insertion unit and is inserted into the insertion unit. A light source unit that selectively introduces white light for illuminating the subject and excitation light for exciting a living tissue toward an incident end surface of a light guide having an emission end surface disposed at the tip, and the light source unit During the period when the white light is introduced into the incident end face of the light guide, image data input from the electronic endoscope is acquired as normal observation image data, and the light source unit is placed on the incident end face of the light guide. In a period in which the light is introduced, an image data acquisition unit that acquires image data input from the electronic endoscope as fluorescence observation image data, and a predetermined process is performed on the image data acquired by the image data acquisition unit. In one of the one or more operation modes, the image processing unit that performs and outputs to the external apparatus, the white light is periodically applied to the incident end surface of the light guide for a short period with respect to the light source unit. In the other period, the excitation light is continuously incident, and the image processing unit is configured to process only the fluorescence observation image data among the image data acquired by the image data acquisition unit. In the control unit, in the operation mode, selected from each luminance value constituting the red component of the normal observation image data acquired by the image data acquisition unit A determination unit that determines whether or not the degree value exceeds a predetermined threshold value, and the light guide is incident on the light source unit only during a period in which the determination unit determines that the luminance value exceeds the threshold value. The white light is incident at least periodically on the end surface, and the image processing unit is caused to output image data for displaying an image including the image of the subject illuminated with the white light to the external device. It is characterized by including a temporary processing control unit.

  With this configuration, when the fluorescence observation image is displayed on the display device because the excitation light is incident almost continuously on the incident end face of the light guide, it is supplied to the light guide between the excitation light outputs. The normal observation image indicated by the normal observation image data acquired on the basis of the white light to be emitted is generally adjusted such that the luminance value selected from the luminance values constituting the red component exceeds a predetermined threshold value. When reddish, the display device displays an image including the image of the subject illuminated with white light, and when the normal observation image is no longer reddish overall, Again, the excitation light is incident almost continuously on the incident end face of the light guide, and the fluorescence observation image is displayed on the display device. For this reason, even if the red color of the normal observation image temporarily increases due to bleeding from the treatment site, the surgeon can safely continue the treatment through the subject image illuminated with white light.

  Therefore, according to the present invention, even when there is bleeding from the treatment site in the treatment through the fluorescence observation image, the treatment can be safely continued.

  Hereinafter, three examples for carrying out the present invention will be described with reference to the accompanying drawings.

Embodiment 1

  FIG. 1 is a configuration diagram of an electronic endoscope system according to a first embodiment of the present invention. The electronic endoscope system according to this embodiment includes an electronic endoscope 10, a main body device 20, and a display device 30.

  The electronic endoscope 10 is an instrument for observing a body cavity where light does not reach. FIG. 2 is a configuration diagram of the electronic endoscope 10. The electronic endoscope 10 is divided into an insertion part 11, an operation part 12, a cable part 13, and a connection part 14.

  The insertion portion 11 is a portion that is inserted into a body cavity, and mainly includes a resin-made cladding tube and a tubular skeleton structure covered with the cladding tube. The skeletal structure flexes flexibly in response to an applied external force and possesses rigidity capable of maintaining the flexed state to such an extent that the body cavity wall is not damaged. The cladding tube and the skeleton structure are not shown. The internal configuration of the insertion unit 11 will be described later.

  The operation unit 12 is a part including various switch buttons 121, an angle knob 122, a forceps port 123, a hose joint 124, and the like, and is connected to the proximal end of the insertion unit 11. The angle knob 122 is illustrated only in FIG. 1, and the hose joint 124 is illustrated only in FIG. The angle knob 122 is a handle for remotely operating a bending mechanism (not shown) incorporated in a portion having a predetermined length from the distal end to the proximal end of the insertion portion 11, and the angle knob 122 is operated. And the bending state of the front-end | tip part of the insertion part 11 changes. The forceps port 123 is an opening for inserting a treatment tool such as a forceps, a scissors, a coagulation electrode, or the like into the thin tube 101 passed through the insertion portion 11 as a forceps channel. However, in FIG. 1, the forceps port 123 is covered. The hose joint 124 is a base for connecting the thin tube 102 drawn through the insertion portion 11 as an air / water supply channel and a hose extending from an air / water supply device (not shown). It is provided on the opposite side of the side.

  The cable unit 13 is an electric rod provided with various signal lines 103 to 105 and a resin tube covering the signal lines 103 to 105, and the tip thereof is connected to the side surface of the operation unit 12. Of the signal lines 103 to 105 routed through the cable unit 13, the signal line 103 is a signal line connected to various switch buttons 121 of the operation unit 12. The remaining signal lines 104 and 105 will be described later.

  The connection portion 14 is a so-called plug for detachably attaching the base end of the cable portion 13 to the main body device 20. The connection unit 14 includes a terminal 141 on a contact surface that faces the main body device 20 when the main body device 20 is attached to a socket (not shown) of the main body device 20. The end portions of the signal lines 103 and 104 among the signal lines 103 to 105 led through the cable portion 13 are connected to the electrodes of the terminal 141.

  The electronic endoscope 10 divided into these parts 11 to 14 further incorporates a light guide 106 made up of a number of bundled optical fibers. The light guide 106 is sequentially passed through the connection portion 14, the cable portion 13, the operation portion 12, and the insertion portion 11, and the proximal end of the light guide 106 protrudes from the abutting surface of the connection portion 14. The metal tube 142 is fixed. The tip portion of the light guide 106 is divided into two bundles by dividing a plurality of optical fibers constituting the light guide 106 into two bundles, and the tips of the branch portions that are bundled are Both are fixed to the distal end of the insertion portion 11.

  Although not shown, five through holes are formed in the distal end surface of the insertion portion 11. Two of the through holes are connected to a narrow tube 101 as a forceps channel and a narrow tube 102 as an air / water supply channel, respectively, and an opening end 111 of the forceps channel and an open end 112 of the air / water supply channel. Function as. A nozzle (not shown) for ejecting the liquid or gas sent through the narrow tube 102 toward the surface of the objective optical system 114 (described later) is attached to the opening end 112 of the air / water supply channel.

  Of the remaining three through holes, light distribution lenses 113 and 113 are fitted into two through holes. As shown in FIG. 2, the tip surfaces of the branch portions formed at the tip portion of the light guide 106 are opposed to the two light distribution lenses 113 and 113, respectively.

  The first lens 114a is fitted in the remaining one through hole. The first lens 114 a constitutes the objective optical system 114 together with the second lens 114 b and the third lens 114 c arranged in the insertion portion 11. The objective optical system 114 is an optical system that forms an image of a subject facing the distal end of the insertion portion 11. An aperture stop 115 is disposed between the first lens 114a and the second lens 114b. The brightness stop 115 is an optical element that limits the amount of light that passes between the first lens 114a and the second lens 114b.

  Further, the insertion unit 11 has a built-in excitation light removal filter 116. The excitation light removing filter 116 is a filter that removes light having the same wavelength band as that of excitation light for causing a phenomenon called fluorescence emission in a living tissue from incident light. The excitation light removal filter 116 is disposed behind the objective optical system 114, and the same wavelength component as the excitation light is removed from the light emitted from the objective optical system 114. FIG. 3 is a graph showing the spectral transmittance of the excitation light removal filter 116. As shown in FIG. 3, the excitation light removal filter 116 transmits light having a wavelength band of about 400 nm or more. The excitation light is composed of wavelength components of about 350 nm to 380 nm.

  Further, the insertion unit 11 has a built-in image sensor 117. The image sensor 117 is a single-plate area image sensor having an imaging surface composed of a large number of pixels arranged two-dimensionally, and a color filter is on-chip on the imaging surface. The image sensor 117 is arranged on the side opposite to the side where the objective optical system 114 is located with the excitation light removal filter 116 interposed therebetween, and the position of the imaging surface coincides with the position of the image plane of the objective optical system 114. Yes.

  Among the signal lines 103 to 105 routed in the cable portion 13, the signal lines 104 and 105 are further led to the insertion portion 11 and connected to the image sensor 117. Of these signal lines 104 and 105, the signal line 104 on the output side of the image sensor 117 is directly connected to the electrode of the terminal 141 of the connection unit 14 as described above. On the other hand, the signal line 105 on the input side of the image sensor 117 is connected to a driver 143 disposed in the connection unit 14, and the signal line 144 on the input side of the driver 143 is connected to the electrode of the terminal 141. ing. The driver 143 is a circuit for controlling the driving of the image sensor 117, and controls the image sensor 117 so as to read the accumulated charge by the interlaced scanning method of 2 fields: 1 frame.

  Further, the connection unit 14 includes a ROM 145. The ROM 145 is a storage device that stores unique information about the electronic endoscope 10. The information may be a model number of the electronic endoscope 10 or a performance value of a component built in the electronic endoscope 10. The performance value includes, for example, the diameter and spectral transmittance of the light guide 106, or the driving voltage and the number of pixels of the image sensor 117. The ROM 145 that stores such information is connected to the electrode of the terminal 141 via the signal line 146.

  The main body device 20 is a processor for controlling the electronic endoscope 10. FIG. 4 is a configuration diagram of the main device 20. The main unit 20 includes a timing control unit 21, a light source unit 22, an image processing unit 23, and a system control unit 24.

  The timing control unit 21 is a device that generates various reference signals and controls the output of the signals. The timing control unit 21 is connected to the light source unit 22, the image processing unit 23, and the system control unit 24, and sends each reference signal to these units 22 to 24.

  When the connection unit 14 of the electronic endoscope 10 is attached to the main body device 20, the timing control unit 21 is connected to the driver 143 in the connection unit 14. When the timing control unit 21 is connected to the driver 143, the timing control unit 21 also sends each reference signal to the driver 143. The driver 143 controls the timing of interlaced scanning according to each reference signal.

  The light source unit 22 is a device for supplying light to the proximal end surface of the light guide 106 of the electronic endoscope 10. When the connecting portion 14 of the electronic endoscope 10 is attached to the main body device 20, the metal tube 142 of the connecting portion 14 is inserted into the light source unit 22, and the proximal end of the light guide 106 is connected to the inside of the light source unit 22. Fixed to.

  FIG. 5 is a configuration diagram of the light source unit 22. The light source unit 22 includes a white light source device 221, a diaphragm mechanism 222, a rotation shielding plate 223, an excitation light source device 224, a dichroic mirror 225, and a condenser lens 226 as its optical configuration.

  The white light source device 221 is a device that emits white light as parallel light. Although not shown, the white light source device 221 is configured to convert white light from a parabolic mirror that converts light emitted from the focal point into parallel light by reflecting the light, and a light emitting point arranged at the focal point of the parabolic mirror. Xenon lamps that emit light are the main components.

  The aperture mechanism 222 has a known structure that changes the diameter of the aperture when a plurality of aperture blades forming a substantially circular aperture are displaced. The aperture is emitted from the white light source device 221 as parallel light. It is coaxially arranged on the optical path of white light. The gear for displacing the aperture blade is engaged with a pinion gear fixed to the tip of the drive shaft of the motor 227. When the motor 227 is driven, the aperture mechanism 222 changes the diameter of the aperture, The amount of white light beam that passes through changes. That is, the diaphragm mechanism 222 functions as white light dimming means.

  The rotation shielding plate 223 is a disc having only one opening. FIG. 6 is a front view of the rotation shielding plate 223. As shown in FIG. 6, the rotation shielding plate 223 has a substantially semicircular opening 223 a. The center of the arc of the opening 223a coincides with the center of the outer circumference of the rotation shielding plate 223, and the center of the rotation shielding plate 223 is fixed to the tip of the drive shaft of the motor 228. The rotation shielding plate 223 is inserted perpendicular to the optical path of white light emitted as parallel light from the white light source device 221, and the white light is incident on the eccentric position of the rotation shielding plate 223. For this reason, when the rotation shielding plate 223 rotates around its central axis by driving the motor 228, the opening 223a is repeatedly inserted in the optical path of white light, and the portion of the rotation shielding plate 223 without the opening 223a is white. Light is shielded periodically. Therefore, the part without the opening 223a in the rotation shielding plate 223 functions as a shutter.

  The excitation light source device 224 is a device that emits the excitation light described above. Although not shown, the excitation light source device 224 includes a collimator lens that converts light emitted from the focal point into parallel light, and a semiconductor that emits laser light having a wavelength band used as excitation light from the focal point of the collimator lens. The laser is the main component. The optical path of the excitation light emitted as parallel light from the excitation light source device 224 is as parallel light from the white light source device 221 on the side opposite to the side where the white light source device 221 is located across the diaphragm mechanism 222 and the rotation shielding plate 223. It is orthogonal to the optical path of the emitted white light.

  The dichroic mirror 225 is an optical element that transmits white light and reflects excitation light. The dichroic mirror 225 is disposed at a position where the optical path of the white light and the optical path of the excitation light intersect, and is inclined by 45 ° with respect to any optical path. Thus, the excitation light emitted as parallel light from the excitation light source device 224 is reflected at a right angle by the dichroic mirror 225 and travels in the same traveling direction as the white light on the same optical path as the white light transmitted through the dichroic mirror 225. Proceed to Therefore, the dichroic mirror 225 functions as an optical path synthesis element.

  The condenser lens 226 is a condenser lens for converging parallel light. The condenser lens 226 is disposed on the optical path of white light that has passed through the dichroic mirror 225 (that is, the optical path of the excitation light reflected by the mirror 225), and is a metal tube of the connection portion 14 of the electronic endoscope 10. The light is converged toward the base end face of the light guide 106 fixed in the lens 142. Therefore, the proximal end surface of the light guide 106 functions as an incident end surface, and the distal end surface of the light guide 106 disposed at the distal end of the insertion portion 11 functions as an emission end surface.

  The light source unit 22 further controls the operations of the light source devices 221 and 224 and the motors 227 and 228 described above, and further includes a first output control circuit 221a, a second output control circuit 224a, a first drive circuit 227a, and A second drive circuit 228a is provided.

  These circuits 221a, 224a, 227a, 228a are all connected to a system control unit 24, which will be described later. In response to an instruction from the system control unit 24, the light sources 221, 224 and motors 227, 228 are connected. Control. Specifically, the system control unit 24 operates the light source unit 22 in one of three operation modes. The three operation modes are a normal observation mode, a fluorescence observation mode, and a special observation mode.

  In the normal observation mode, the first output control circuit 221a causes the white light source device 221 to continuously output white light, the second output control circuit 224a stops driving the excitation light source device 224, and the second drive circuit 228a. Inserts the opening 223a of the rotation shielding plate 223 into the optical path of white light. As a result, only white light is continuously incident on the incident end face of the light guide 106. As a result, white light is continuously emitted from the emission end face of the light guide 106 toward the front end of the insertion portion 11 of the electronic endoscope 10.

  In the fluorescence observation mode, the first output control circuit 221a stops driving the white light source device 221, and the second output control circuit 224a causes the excitation light source device 224 to continuously output excitation light. Thereby, only the excitation light continuously enters the incident end face of the light guide 106. As a result, excitation light is continuously emitted from the emission end face of the light guide 106 toward the front end of the insertion portion 11 of the electronic endoscope 10.

  In the special observation mode, the first output control circuit 221 a causes the white light source device 221 to continuously output white light, and the second output control circuit 224 a outputs the excitation light to the excitation light source device 224 periodically. The second driving circuit 228a rotates the rotation shielding plate 223. At this time, the second output control circuit 224a and the second drive circuit 228a control the excitation light source device 224 and the second drive circuit 228a according to the signal input from the timing control unit 21. Specifically, the second output control circuit 224a is configured to output the excitation light so that the excitation light is output only while the image sensor 117 accumulates the charge corresponding to the image data of the second field in one frame described above. The output cycle of 224 is controlled, and the second drive circuit 228a inserts the opening 223a into the optical path of white light only while the image sensor 117 accumulates charges corresponding to the image data of the first field in one frame. Thus, the rotational phase of the rotation shielding plate 223 is controlled. Thereby, white light and excitation light are incident on the incident end face of the light guide 106 alternately. As a result, white light and excitation light are alternately emitted from the emission end face of the light guide 106 toward the front end of the insertion portion 11. FIG. 7 is a timing chart of light emitted from the distal end of the insertion portion 11 in the special observation mode.

  In the light source unit 22 operating in any one of the operation modes described above, as shown in FIG. 5, the first drive circuit 227a is further connected to an image processing unit 23 described later, and image processing is performed. A signal described later is input from the unit 23. The first drive circuit 227a controls the diameter of the aperture of the diaphragm mechanism 222 according to this input signal.

  The image processing unit 23 is a device for performing predetermined processing on image data (image signal) generated by the image sensor 117 in the insertion unit 11 of the electronic endoscope 10 and converting the image data into a video signal. When the connection unit 14 of the electronic endoscope 10 is attached to the main body device 20, the image processing unit 23 includes the terminal 141 of the connection unit 14 and the signal lines in the units 11 to 14 of the electronic endoscope 10. The image pickup device 117 is connected to the image pickup device 117 in the distal end of the insertion portion 11 through 105. FIG. 4 shows a state where the image processing unit 23 is connected to the image sensor 117.

  FIG. 8 is a configuration diagram of the image processing unit 23. The image processing unit 23 includes a pre-stage processing circuit 231, a first matrix circuit 232, a first RGB memory 233, a second RGB memory 234, a post-stage processing circuit 235, a second matrix circuit 236, a frequency distribution generation circuit 237, and a comparison circuit 238. Have.

  The pre-processing circuit 231 is a circuit for converting the data format of the image data output by the image sensor 117 in the insertion unit 11 of the electronic endoscope 10 in the form of analog signal transmission into a data format suitable for the subsequent processing. It is. Specifically, the pre-processing circuit 231 performs processing such as color separation, digitization, and color space conversion on the analog signal input from the image sensor 117, thereby converting RGB color component image data. After generation, general processing such as color balance is performed on the generated image data.

  Further, the pre-stage processing circuit 231 performs a process of outputting a signal to the first drive circuit 227a of the light source unit 22 only during a period instructed by the system control unit 24 described later. In this processing, the pre-stage processing circuit 231 extracts the luminance signal of the first field in one frame from the analog signal input from the image sensor 117, reads the highest luminance level in this luminance signal, and this luminance level is The aperture diameter of the diaphragm mechanism 222 is calculated so as to reach a predetermined level, and a signal instructing to set the aperture diameter is output to the first drive circuit 227a. That is, the output amount of white light is feedback-controlled by the pre-processing circuit 231 and the second drive circuit 228a.

  The pre-processing circuit 231 is connected to the first RGB memory 233 and the second RGB memory 234, and sequentially converts the RGB color component image data subjected to the above-described processing into the first RGB memory 233 and the first RGB memory 233. The data is output to the 2RGB memory 234. Further, the pre-processing circuit 231 is also connected to the first matrix circuit 232 and outputs the RGB image data of the second field to the first matrix circuit 232.

  The first matrix circuit 232 is a circuit for generating image data of a luminance component (Y component) from RGB image data. The first matrix circuit 232 outputs the luminance component image data to the system control unit 24. The luminance component image data is used in the system control unit 24 for output control of the excitation light source device 224 of the light source unit 22 in the fluorescence observation mode or the special observation mode. That is, the first matrix circuit 232 is a circuit used for feedback control of the output amount of the excitation light.

  Each of the first RGB memory 233 and the second RGB memory 234 is a storage device for temporarily recording image data of RGB color components. Whether or not both memories 233 and 234 store image data is controlled by the timing control unit 21 instructed to the system control unit 24 described later. Further, the timing of outputting the image data stored in both memories 233 and 234 is also controlled by the timing control unit 21. Specifically, the timing control unit 21 operates each of the memories 233 and 234 in any one of the normal observation mode, the fluorescence observation mode, and the special observation mode described above.

  In the normal observation mode, the timing control unit 21 temporarily stores all input image data in the first RGB memory 233, and outputs the stored image data in accordance with the processing start timing of the post-processing circuit 235 described later. Let On the other hand, for the second RGB memory 234, the timing control unit 21 does not store all input image data. As a result, only the first RGB memory 233 is used for temporary storage of image data. In the normal observation mode, the light source unit 22 supplies white light to the light guide 106 of the electronic endoscope 10 as described above. For this reason, the image data stored in the first RGB memory 233 in the normal observation mode is formed by the light reflected on the surface of the white light incident on the surface of the body cavity wall in front of the distal end of the insertion portion 11. Based on the image to be generated by the image sensor 117. Hereinafter, this image data will be referred to as “normal observation image data” for convenience.

  In the fluorescence observation mode, the timing control unit 21 does not store all input image data in the first RGB memory 233. On the other hand, for the second RGB memory 234, the timing control unit 21 temporarily stores all input image data, and outputs the stored image data in accordance with the processing start timing of the later-stage processing circuit 235 described later. . As a result, only the second RGB memory 234 is used for temporary storage of image data. In the fluorescence observation mode, as described above, the light source unit 22 supplies excitation light to the light guide 106 of the electronic endoscope 10. For this reason, the image data stored in the second RGB memory 234 in the fluorescence observation mode is based on the image formed by the fluorescence emitted from the living tissue under the body cavity wall irradiated with the excitation light. Will be generated. Hereinafter, this image data is referred to as “fluorescence observation image data” for convenience.

  In the special observation mode, the timing control unit 21 temporarily stores the first field image data in one frame described above in the first RGB memory 233 and does not store the second field image data. On the other hand, for the second RGB memory 234, the timing control unit 21 temporarily stores the image data of the second field without storing the image data of the first field in one frame. Accordingly, the first RGB memory 233 is used for temporary storage of the image data of the first field, and the second RGB memory 234 is used for temporary storage of the image data of the second field. Then, the timing control unit 21 causes the RGB memories 233 and 234 to output the image data being stored in accordance with the processing start timing of the later-stage processing circuit 235 described later. In this special observation mode, as described above, the light source unit 22 supplies white light and excitation light alternately to the light guide 106 of the electronic endoscope 10 in accordance with the timing of the first field and the second field. To do. For this reason, the image data stored in the first RGB memory 233 under the special observation mode is the normal observation image data described above, and the image data stored in the second RGB memory 234 under the special observation mode is the fluorescence observation image described above. It becomes data.

  The post-processing circuit 235 is a circuit for converting the data format of the image data for each RGB color component into a data format suitable for output to an external device. Specifically, in the normal observation mode, the post-stage processing circuit 235 performs general processing such as analogization and encoding on the RGB color component image data output from the first RGB memory 233, thereby skipping. For example, a video signal such as an NTSC signal conforming to the scanning method is generated. Further, in the fluorescence observation mode, the post-processing circuit 235 generates a video signal by performing the above-described general processing on the image data of each RGB color component output from the second RGB memory 234.

  In the special observation mode, the post-processing circuit 235 includes a normal observation image based on the normal observation image data output from the first RGB memory 233 and a fluorescence observation image based on the fluorescence observation image data output from the second RGB memory 234. Is generated at the same time within one screen, and a video signal is generated by applying the above-described general processing to the image data.

  The post-processing circuit 235 outputs the generated video signal to the display device 30 connected to the external output terminal. The display device 30 displays an image based on the image data output from the image processing unit 23 in a video signal transmission form.

  Similar to the first matrix circuit 232, the second matrix circuit 236 is a circuit for generating luminance component image data from RGB image data. The second matrix circuit 236 is connected to the output side of the second RGB memory 234. The second matrix circuit 236 receives the fluorescence observation image data in the fluorescence observation mode or the special observation mode from the second RGB memory 234. Are sequentially input.

  The frequency distribution generation circuit 237 is a circuit that generates frequency distribution data by counting the frequency of a sample for each class of luminance values using each pixel of the luminance component image data as a sample. When the frequency distribution generation circuit 237 generates the frequency distribution data based on the luminance component of the fluorescence observation image data input from the second matrix circuit 236, the frequency distribution generation circuit 237 outputs the frequency distribution data to the comparison circuit 238.

  The comparison circuit 238 reads out the luminance value of the class to which the predetermined sample belongs from the minimum value to the maximum value in the frequency distribution data as a comparison target value, and outputs a signal when the comparison target value is below a predetermined threshold value. It is a circuit to output.

  FIG. 9 is a graph used to explain the relationship between the comparison target value and the threshold value. In FIG. 9, the comparison target value for frequency distribution data A for image data of an overall dark image, that is, frequency distribution data A for which samples are concentrated on the relatively lower side is shown as “X”. ing. On the other hand, the frequency distribution data B for the image data of a bright image as a whole, that is, the comparison target value for the frequency distribution data B in which the samples are concentrated on the relatively higher side is shown as “Z”. Yes. The shaded area indicates the number of samples up to a predetermined number.

  As shown in FIG. 9, the threshold Y is set to a luminance value higher than the comparison target value X. In this case, when the frequency distribution data A is input, the comparison circuit 238 outputs a signal. On the other hand, the threshold value Y is set to a luminance value lower than the comparison target value Z. In this case, the comparison circuit 238 does not output a signal even when the frequency distribution data B is input. That is, the comparison circuit 238 outputs a signal when image data of a dark image as a whole is output from the second RGB memory 234. The comparison circuit 238 is connected to the system control unit 24, and a signal is output to the system control unit 24.

  The system control unit 24 is a device for controlling the entire main device 20. The system control unit 24 is configured such that when the connection unit 14 of the electronic endoscope 10 is attached to the main body device, various switch buttons 121 of the operation unit 12 are connected via the terminals 141 and the signal line 103 of the connection unit 14. Connected to. FIG. 4 shows a state where the system control unit 24 is connected to the switch button 121. These switch buttons 121 include a switch button for switching the operation mode described above. Each time the switch button 121 is pressed, the system control unit 24 sets the operation mode to the normal observation mode. The setting is canceled alternately. The details of the control of the main body device 20 relating to the switching of the normal observation mode will be described later with reference to FIG.

  In addition, when the connection unit 14 of the electronic endoscope 10 is attached to the main body apparatus, the system control unit 24 is connected to the ROM 145 in the connection unit 14 via the terminal 141 and the signal line 146 of the connection unit 14. Connected. FIG. 4 shows a state where the system control unit 24 is connected to the ROM 145. When connected to the ROM 145, the system control unit 24 can read unique information about the electronic endoscope 10 from the ROM 145.

  Further, as shown in FIG. 4, the system control unit 24 includes an operation panel 241 installed on the front surface of the main body device 20. The operation panel 241 includes various switch buttons, menu buttons, and up / down key buttons. One of these buttons is a switching button for switching the operation mode when the normal observation mode is disconnected. FIG. 10 is a front view of the switching button 241a. As shown in FIG. 10, the operation panel 241 includes an indicator lamp 241b on the upper side of the switching button 241a, and the indicator lamp 241b switches between a lighting state and an unlighting state each time the switching button 241a is pressed. It is done. When the switch button 241a is pressed and the indicator lamp 241b is turned off, the system control unit 24 sets the operation mode to the fluorescence observation mode. When the switch button 241a is pressed again and the indicator lamp 241b is turned on, the system control unit 24 operates. Set the mode to the special observation mode.

  The system control unit 24 stores a program for overall control of the main unit 20 in a storage device (not shown). When the main power is turned on, the system control unit 24 reads the program from the storage device and performs overall control. Start processing. FIG. 11 is a flowchart showing the contents of this overall control process.

  In the first step S1001 after the start of processing, the system control unit 24 reads information from the ROM 145 in the connection unit 14 attached to the main body device 20. Here, when the connection unit 14 is not attached to the main body device 20, the system control unit 24 stands by until it is attached, and when attached, reads information from the ROM 145 in the attached connection unit 14. When the system control unit 24 reads information from the ROM 145, the system control unit 24 sets the output amounts of the white light source device 221 and the excitation light source device 224 as initial values based on the read information. Further, the system control unit 24 sets, for example, a normal observation mode as an initial state of the operation mode.

  In the next step S1002, the system control unit 24 determines whether or not the operation mode is set to the normal observation mode. If it is determined that the normal observation mode is set (S1002; YES), the system control unit 24 advances the process to step S1003.

  In step S1003, the system control unit 24 starts control of each circuit 221a, 224a, 227a, 228a of the light source unit 22 so that the light source unit 22 and the image processing unit 23 operate in the normal observation mode, and at the timing. Control of the hardware 231 to 235 in the image processing unit 23 is started through the control unit 21. After the start, the system control unit 24 advances the processing to step S1011.

  On the other hand, if it is determined in step S1002 that the operation mode is not set to the normal observation mode (S1002; NO), the system control unit 24 advances the processing to step S1004.

  In step S1004, the system control unit 24 determines whether the operation mode is set to the fluorescence observation mode or the special observation mode (that is, whether the indicator lamp 241b shown in FIG. 10 is turned off or turned on). Determine. If it is determined that the operation mode is set to the fluorescence observation mode (S1004; YES), the system control unit 24 advances the process to step S1005.

  In step S1005, the system control unit 24 starts control of each circuit 221a, 224a, 227a, 228a of the light source unit 22 and timing control so that the light source unit 22 and the image processing unit 23 operate in the fluorescence observation mode. Control of the hardware 231 to 235 in the image processing unit 23 is started through the unit 21. After the start, the system control unit 24 advances the processing to step S1011.

  On the other hand, if it is determined in step S1004 that the operation mode is set to the special observation mode (S1004; NO), the system control unit 24 advances the processing to step S1006.

  In step S1006, the system control unit 24 starts control of each circuit 221a, 224a, 227a, 228a of the light source unit 22 and timing control so that the light source unit 22 and the image processing unit 23 operate in the special observation mode. Control of the hardware 231 to 235 in the image processing unit 23 is started through the unit 21. After the start, the system control unit 24 advances the processing to step S1011.

  The system control unit 24 performs steps S1002 to S1002 described above when an operation is performed on the switch button 121 of the operation unit 12 of the electronic endoscope 10 and / or the switching button 241a of the operation panel 241 of the main body device 20. By executing the processing of S1006, the execution of the operation mode after switching is started. Then, after starting execution of such an operation mode, the system control unit 24 executes a processing loop of steps S1011 to S1019.

  In step S1011, the system control unit 24 determines whether or not the operation mode is set to the fluorescence observation mode. If it is determined that the operation mode of the main unit 20 is set to the fluorescence observation mode (S1011; YES), the system control unit 24 advances the process to step S1012.

  In step S1012, the system control unit 24 determines whether a signal is received from the comparison circuit 238. If the system control unit 24 determines that no signal is received from the comparison circuit 238 (S1012; NO), the system control unit 24 proceeds to step S1017 and determines that a signal is received from the comparison circuit 238 ( (S1012; YES), the process proceeds to step S1013.

  In step S1013, the system control unit 24 causes the main body device 20 to start an operation in the temporary mode. The temporary mode is a mode in which the light source unit 22 and the image processing unit 23 are operated in an operation mode similar to the special observation mode only during a period in which a signal is output from the comparison circuit 238. That is, in the temporary mode, the light source unit 22 supplies white light and excitation light to the light guide 106 of the electronic endoscope 10, and the image processing unit 23 captures normal observation image data and fluorescence observation image data. Acquired alternately from the element 117 and processed. After setting the operation mode to the temporary mode, the system control unit 24 starts the operations of the light source unit 22 and the image processing unit 23 in the temporary mode. Thereafter, the system control unit 24 advances the processing to step S1017.

  On the other hand, when it is determined in step S1011 that the operation mode is not set to the fluorescence observation mode (S1011; NO), the system control unit 24 advances the processing to step S1014.

  In step S1014, the system control unit 24 determines whether or not the operation mode is set to the temporary mode. If the system control unit 24 determines that the operation mode is not set to the temporary mode (S1014; NO), the system control unit 24 proceeds to step S1017 and determines that the operation mode of the main unit 20 is set to the temporary mode. If it is determined (S1014; YES), the process proceeds to step S1015.

  In step S1015, the system control unit 24 determines whether or not a signal is received from the comparison circuit 238. If the system control unit 24 determines that the signal is not received from the comparison circuit 238 (S1015; NO), the system control unit 24 proceeds to step S1017 and determines that the signal is received from the comparison circuit 238 ( (S1015; YES), the process proceeds to step S1016.

  In step S1016, the system control unit 24 cancels the temporary mode by setting the operation mode to the fluorescence observation mode. Thereafter, the system control unit 24 causes the light source unit 22 and the image processing unit 23 to start operation in the fluorescence observation mode. Then, the system control unit 24 advances the processing to step S1017.

  In step S1017, the system control unit 24 determines whether or not the operation mode setting has been changed in the operation unit 12 of the electronic endoscope 10. If it is determined that the setting of the observation mode has not been changed (S1017; NO), the system control unit 24 advances the process to step S1018.

  In step S <b> 1018, the system control unit 24 determines whether or not the connection unit 14 of the electronic endoscope 10 is detached from the main body device 20. If it is determined that the connection unit 14 of the electronic endoscope 10 has not been removed from the main body device 20 (S1018; NO), the system control unit 24 advances the processing to step S1019.

  In step S1019, the system control unit 24 determines whether or not a switch button (not shown) for cutting off the main power source is pressed on the operation panel 241. If it is determined that the main power-off switch button has not been pressed (S1019; NO), the system control unit 24 advances the process to step S1011.

  If it is determined that the setting of the operation mode has been changed during execution of the processing loop from step S1011 to step S1019 (S1017; YES), the system control unit 24 branches the processing from step S1017 to step S1002.

  If it is determined that the connection unit 14 of the electronic endoscope 10 has been removed from the main body device 20 during execution of the processing loop (S1018; YES), the system control unit 24 proceeds from step S1018 to step S1001. Branch processing.

  If the system control unit 24 determines that the main power-off switch button has been pressed during execution of the processing loop (S1019; YES), the system control unit 24 branches the processing from step S1019, and the main device 20 The overall control process ends.

  The system control unit 24 executes the processing loop from step S1011 to step S1019 described above to determine whether there has been an operation mode switching operation, whether a connection has been attached or detached, whether there has been a main power-off operation, Each monitor whether or not to enter the mode. The system control unit 24 executes a process for switching the operation mode when there is an operation mode switching operation, and ends the overall control process when there is a main power-off operation, and shifts to the temporary mode. When there is a signal from the image processing unit, the mode is shifted to the temporary mode.

  Since it is configured as described above, the electronic endoscope system according to the first embodiment has operations and effects as described below.

  An operator who performs an operation on a subject using the electronic endoscope system according to the first embodiment first connects the display device 30 and the main body device 20 and turns on each main power supply. Subsequently, the surgeon attaches the connection unit 14 of the electronic endoscope 10 to the main body device 20 and operates the switch button 121 of the operation unit 12 to switch the operation mode to the normal observation mode. Then, as described above, the opening 223a of the rotation shielding plate 223 is disposed in the optical path of the white light, and the white light is emitted from the white light source device 221. As a result, white light is continuously emitted from the distal end of the insertion portion 11 of the electronic endoscope 10.

  When the operator inserts the distal end of the insertion portion 11 emitting white light into a respiratory organ such as the lung or bronchus of the subject, white light is irradiated into the body cavity, and the surface of the body cavity wall is irradiated. A part of the incident white light reflected by the surface thereof is transmitted through the objective optical system 114 and the excitation light removing filter 116 and is incident on the imaging surface of the image sensor 117. The image of the body cavity wall formed on the imaging surface by the light transmitted through the objective optical system 114 and the excitation light removal filter 116 is converted into normal observation image data by the imaging device 117, and general processing is performed in the image processing unit 23. The image is output to the display device 30 and finally displayed on the display device 30 as a color normal observation image. FIG. 12 is a diagram illustrating an example of a normal observation image. The surgeon can observe the state of the body cavity wall and perform treatment using a treatment tool such as forceps through the normal observation image as shown in FIG.

  Subsequently, when the surgeon determines that it is necessary to perform fluorescence observation on the part selected through observation of the color normal observation image, the operator operates the switch button 121 of the operation unit 12 of the electronic endoscope 10. Thus, after canceling the normal observation mode, the indicator lamp 241b is turned off by pressing a switch button (see FIG. 10) 241a on the operation panel 241 of the main unit 20, and the operation mode is switched to the fluorescence observation mode. Then, as described above, the excitation light is emitted from the excitation light source device 224. As a result, excitation light is continuously emitted from the distal end of the insertion portion 11 of the electronic endoscope 10.

  Then, a part of the fluorescence emitted from the living tissue under the body cavity wall excited by the excitation light and a part of the excitation light reflected by the surface of the body cavity wall are incident on the objective optical system 114. From the light emitted from the objective optical system 114 toward the image sensor 117, light having the same wavelength band as the excitation light is removed by the excitation light removal filter 116, and only fluorescence enters the imaging surface of the image sensor 117. . The image of the body cavity wall formed on the imaging surface by the fluorescence transmitted through the objective optical system 114 and the excitation light removal filter 116 is converted into fluorescence observation image data by the imaging element 117, and general processing is performed in the image processing unit 23. The result is output to the display device 30 and finally displayed on the display device 30 as a color fluorescence observation image. FIG. 13 is a diagram illustrating an example of a fluorescence observation image. The surgeon can observe the state of the biological tissue under the body cavity wall or perform a treatment using a treatment tool such as forceps through the fluorescence observation image as shown in FIG.

  In addition, when observing the fluorescence observation image, when it becomes necessary to compare with the normal observation image or to confirm the state of the treatment tool that does not emit fluorescence, the operator can check the state of the main body device 20. When the switch button (see FIG. 10) 241a on the operation panel 241 is pressed, the indicator lamp 241b is turned on to switch the operation mode to the special observation mode. Then, as described above, the rotation shielding plate 223 is rotated, white light is emitted from the white light source device 221, and excitation light is periodically emitted from the excitation light source device 224. Accordingly, white light and excitation light are alternately emitted from the distal end of the insertion portion 11 of the electronic endoscope 10.

  During the period in which the white light is emitted from the distal end of the insertion portion 11, a part of the light reflected on the surface of the white light incident on the surface of the body cavity wall passes through the objective optical system 114 and passes through the objective optical system 114. Incident on the imaging surface. The image of the body cavity wall formed on the imaging surface by the light transmitted through the objective optical system 114 and the excitation light removal filter 116 is converted into normal observation image data by the imaging element 117 and output to the image processing unit 23. On the other hand, during the period in which the excitation light is emitted from the distal end of the insertion portion 11, part of the fluorescence emitted by the biological tissue under the body cavity wall irradiated with the excitation light passes through the objective optical system 114 and the excitation light removal filter 116. Then, the light enters the image pickup surface of the image pickup element 117. The image of the body cavity wall formed on the imaging surface by the fluorescence transmitted through the objective optical system 114 and the excitation light removal filter 116 is converted into fluorescence observation image data by the imaging element 117 and output to the image processing unit 23. Then, as described above, each time the normal observation image data and the fluorescence observation image data for one field are input, the image processing unit 23 generates a composite image that simultaneously displays images based on both image data on one screen. Image data is generated and output to the display device 30. The display device 30 displays a composite image based on the image data. FIG. 14 is a diagram illustrating an example of a composite image. The surgeon can observe and perform the treatment while comparing the normal observation image and the fluorescence observation image through the composite image.

  Furthermore, when the operation mode is the fluorescence observation mode, if most of the body cavity wall is covered with blood from the treatment site, the blood does not emit fluorescence even when irradiated with excitation light. As shown, the image of the bleeding part becomes black and the fluorescence observation image becomes dark overall. In this case, observation through the fluorescence observation image cannot be performed. However, when the fluorescence observation image becomes dark as a whole as described above, a signal is sent from the comparison circuit 238 of the image processing unit 23 to the system control unit 24. Upon receiving this signal, the system control unit 24 switches the operation mode to the temporary mode, and displays a composite image of the normal observation image and the fluorescence observation image on the display device 30. Conversely, in the temporary mode, the brightness of the fluorescence observation image returns when the surface of the body cavity wall is washed away with physiological saline and is not covered with blood and the normal mucous membrane is exposed. Then, the output of the signal from the comparison circuit 238 stops. In response to this, the system control unit 24 returns the operation mode from the temporary mode to the fluorescence observation mode. Thus, even if the observation of the fluorescence observation image becomes impossible due to bleeding from the treatment site during the operation in the fluorescence observation mode, the composite image is immediately displayed. You can perform operations and perform hemostasis.

Embodiment 2

  FIG. 15 is a configuration diagram of the image processing unit 23 in the electronic endoscope system according to the second embodiment. FIG. 16 is a graph used to explain the relationship between the comparison target value and the threshold in the second embodiment.

  The electronic endoscope system of the second embodiment has almost the same configuration as that of the first embodiment, but is different from the first embodiment only in three points.

  The first difference is that the R image of the RGB image data output from the second RGB memory 234 instead of the absence of the second matrix circuit 236, as is apparent from a comparison between FIG. 15 and FIG. Only data is input to the frequency distribution generation circuit 237.

  The second difference is that the luminance value read as a comparison target value from the frequency distribution data (frequency distribution data for the R image data) by the comparison circuit 238 of the second embodiment is changed from the minimum value to the maximum value in the frequency distribution data. On the other hand, it is not the luminance value of the class to which the predetermined sample belongs, but the luminance value of the class to which the sample in the middle of the whole (that is, the intermediate value) belongs.

  The third difference is that the temporary mode in which the system control unit 24 operates only during the period when the signal is output from the comparison circuit 238 is not the same operation mode as the special observation mode, but the same operation mode as the normal observation mode. It has become. That is, in the temporary mode, the normal observation image is displayed on the display device 30 instead of the composite image of the normal observation image and the fluorescence observation image.

  By the way, the part of the body cavity wall not covered with blood emits fluorescence when irradiated with excitation light. Since the fluorescence contains a red component, when there is no bleeding or the portion covered with blood is small even if there is bleeding, the frequency distribution data is relatively classified as shown in graph D in FIG. A graph with samples concentrated on the higher side. In FIG. 16, the luminance value of the class to which the intermediate value of the frequency distribution data D belongs is shown as “S”.

  On the other hand, as described above, the portion of the body cavity wall covered with blood does not emit fluorescence even when the blood is irradiated with excitation light. For this reason, when the portion covered with blood is large, the frequency distribution data is a graph in which samples are concentrated on the relatively lower class side, as in graph C in FIG. In FIG. 16, the luminance value of the class to which the intermediate value of the frequency distribution data C belongs is indicated as “Q”.

  As shown in FIG. 16, the threshold value R is set to a luminance value higher than the comparison target value Q. In this case, when the frequency distribution data C is input, the comparison circuit 238 outputs a signal. On the other hand, the threshold value R is set to a luminance value lower than the comparison target value S. In this case, even if the frequency distribution data D is input, the comparison circuit 238 does not output a signal. That is, the comparison circuit 238 outputs a signal to the system control unit 24 when the dark R image data is output from the second RGB memory 234.

  Even when configured in this way, when the operation mode is the fluorescence observation mode, the R component of the fluorescence observation image becomes dark overall as a result of most of the body cavity wall being covered with blood from the treatment site. When a signal is sent from the comparison circuit 238 of the image processing unit 23 to the system control unit 24, the system control unit 24 receives this signal and switches the operation mode to the temporary mode. As a result, the normal observation image (see FIG. 12) is displayed on the display device 30.

  That is, also in the second embodiment, even if the observation of the fluorescence observation image becomes impossible due to bleeding from the treatment site during the operation in the fluorescence observation mode, the normal observation image is displayed immediately. Therefore, the treatment instrument can be operated or hemostasis can be performed.

Embodiment 3

  FIG. 17 is a configuration diagram of the image processing unit 23 of the third embodiment.

  The electronic endoscope system of the third embodiment has almost the same configuration as that of the first embodiment, but is different from the first embodiment in only five points.

  As a first difference, although not shown, a chopper is arranged in the light source unit 22 instead of the rotation shielding plate 223 of FIG. The chopper is a semicircular plate, and the center of the arc of the chopper is fixed to the tip of the drive shaft of the motor 228, like the rotation shielding plate 223 of the first embodiment. The chopper is installed so as to be perpendicular to the traveling direction of the white light emitted as the parallel light from the white light source device 221, and the drive shaft of the motor 228 is shifted from the optical path of the white light. It is arranged at the position. For this reason, when the chopper (not shown) rotates around its central axis by driving the motor 228, the chopper is repeatedly inserted into the optical path of white light, and the white light is periodically shielded. That is, the chopper (not shown) functions in the same manner as the rotation shielding plate 223 of the first embodiment.

  The second difference is that the R image of the RGB image data output from the first RGB memory 234 instead of the absence of the second matrix circuit 236, as is clear by comparing FIG. 15 and FIG. Only data is input to the frequency distribution generation circuit 237.

  The third difference is that the luminance value read as a comparison target value from the frequency distribution data (frequency distribution data for R image data) by the comparison circuit 238 of the third embodiment is changed from the maximum value to the minimum value in the frequency distribution data. On the other hand, it is not the luminance value of the class to which the predetermined sample belongs, but the luminance value of the class to which the sample in the middle of the whole (that is, the intermediate value) belongs (see FIG. 16).

  The fourth difference is that, in the fluorescence observation mode, the system control unit 24 does not cause the excitation light to continuously enter the incident end face of the light guide 106, but emits the excitation light for 59/60 seconds. / The operation of emitting white light for 60 seconds is repeated. Specifically, the first output control circuit 221a of the light source unit 22 causes the white light source device 221 to continuously output white light. The second drive circuit 228a allows white light to be incident on the incident end face of the light guide 106 only while the image sensor 117 accumulates charges corresponding to the image data of the first field in 60 fields (30 frames). Thus, the rotational phase of a chopper (not shown) is controlled. Furthermore, the second output control circuit 224a controls the output cycle of the excitation light source device 224 so that the excitation light is output only during a period other than the period during which white light is emitted. FIG. 18 is a timing chart of light emitted from the distal end of the insertion portion 11 in the fluorescence observation mode.

  As a fifth difference, in the fluorescence observation mode, the timing control unit 21 temporarily stores the image data of the first field in the 60 frames described above in the first RGB memory 233 and stores the other image data. I won't let you. On the other hand, for the second RGB memory 234, the timing control unit 21 temporarily stores the image data of the second to 60 fields in the 60 fields described above, and does not store the other image data. Then, the timing control unit 21 causes the RGB memories 233 and 234 to output the image data being stored in accordance with the processing start timing of the later-stage processing circuit 235 described later. In the fluorescence observation mode, the post-processing circuit 235 performs the above-described general processing only on the image data of each RGB color component output from the second RGB memory 234, as in the first embodiment. To generate a video signal. However, the fluorescence observation image displayed on the display device 30 based on this video signal is missing only one field of 1/30 frames.

  According to the second to fifth differences, in the fluorescence observation mode of the third embodiment, only the fluorescence observation image data is processed in the post-processing circuit 235, and the fluorescence observation image is displayed on the display device 30. On the other hand, the normal observation image data (the R component thereof) is used for determining the presence or absence of bleeding. Here, the comparison circuit 238 of the third embodiment is configured to send a signal when the comparison target value exceeds the threshold for the frequency distribution data of the R component of the normal observation image data. This is to detect that the R component of the normal observation image data becomes bright when most of the body cavity wall is covered with blood from the treatment site and most of the normal observation image becomes red. It is.

  Even when configured in this manner, when the operation mode is the fluorescence observation mode, when the fluorescence observation image becomes entirely dark because the most part of the body cavity wall is covered with the blood that has come out from the treatment site ( When the normal observation image turns red as a whole), a signal is sent from the comparison circuit 238 of the image processing unit 23 to the system control unit 24, and the system control unit 24 receives this signal and changes the operation mode. Switch to temporary mode. As a result, a composite image (see FIG. 14) of the normal observation image and the fluorescence observation image is displayed on the display device 30.

  That is, also in the third embodiment, even if the observation of the fluorescence observation image becomes impossible due to bleeding from the treatment site during the operation in the fluorescence observation mode, the composite image is immediately displayed. Therefore, the treatment tool can be operated or hemostasis can be performed.

  In the temporary mode of the third embodiment, the composite image may be displayed on the display device 30, but the normal observation image may be displayed on the display device 30.

The block diagram of the electronic endoscope system which is 1st Embodiment of this invention. Configuration diagram of electronic endoscope Graph showing spectral transmittance of excitation light removal filter Configuration diagram of main unit Configuration diagram of light source unit Front view of rotating shield Timing chart of light emitted from the tip of the insertion section under special observation mode Configuration diagram of image processing unit A graph used to explain the relationship between the comparison target value and the threshold Front view of switching button Flow chart showing contents of overall control processing Diagram showing an example of a normal observation image Diagram showing an example of a fluorescence observation image Diagram showing an example of a composite image The block diagram of the image processing unit in the electronic endoscope system of 2nd Embodiment A graph used to explain the relationship between the comparison target value and the threshold Configuration diagram of image processing unit of third embodiment Timing chart of light emitted from the distal end of the insertion section under the fluorescence observation mode

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electronic endoscope 101 Thin tube 102 Thin tube 103 Signal line 104 Signal line 105 Signal line 106 Light guide 11 Insertion part 111 Open end 112 Open end 113 Light distribution lens 114 Objective optical system 114a Lens 114b Lens 114c Lens 115 Diaphragm 116 Excitation light removal Filter 117 Image sensor 12 Operation unit 121 Switch button 122 Angle knob 123 Forceps port 124 Hose joint 13 Cable unit 14 Connection unit 141 Terminal 142 Metal tube 143 Driver 144 Signal line 145 ROM
146 Signal line 20 Main device 21 Timing control unit 22 Light source unit 221 White light source device 221a Output control circuit 222 Aperture mechanism 223 Rotation shielding plate 223a Opening 224 Excitation light source device 224a Output control circuit 225 Dichroic mirror 226 Condensing lens 227 Motor 227a Drive circuit 228 Motor 228a Drive circuit 23 Image processing unit 231 Pre-processing circuit 231a Menu button 232 Matrix circuit 233 First RGB memory 234 Second RGB memory 235 Post-processing circuit 236 Matrix circuit 237 Frequency distribution generation circuit 238 Comparison circuit 24 System control unit 241 Operation panel 241a Switch button 241b Indicator lamp 30 Display device

Claims (8)

An electronic endoscope having an insertion portion to be inserted into the body cavity of the subject is detachably mounted, and image data obtained by imaging a subject facing the distal end of the insertion portion is input to the electronic endoscope An endoscope processor,
White light for illuminating the subject and excitation light for exciting the living tissue are directed toward the incident end surface of the light guide that is passed through the insertion portion and has an emission end surface disposed at the distal end of the insertion portion. Light source part to be introduced selectively,
During the period in which the light source unit introduces the white light to the incident end face of the light guide, image data input from the electronic endoscope is acquired as normal observation image data, and the light source unit is incident on the light guide. In a period in which the excitation light is introduced into the end face, an image data acquisition unit that acquires image data input from the electronic endoscope as fluorescence observation image data;
An image processing unit that performs predetermined processing on the image data acquired by the image data acquisition unit and outputs the processed image data to an external device;
In the case where the light source unit causes the excitation light to continuously enter the incident end face of the light guide, among the luminance values constituting at least one color component of the fluorescence observation image data acquired by the image data acquisition unit. A determination unit for determining whether or not the luminance value selected from is below a predetermined threshold;
Only during a period when the determination unit determines that the luminance value is lower than the threshold, the white light is incident on the light guide unit at least periodically on the incident end surface of the light guide, and the image processing is performed. An electronic endoscope processor, comprising: a temporary processing control unit that outputs to the external device image data for displaying an image including an image of the subject illuminated with the white light. . The temporary processing control unit continuously incident the white light on the incident end surface of the light guide with respect to the light source unit during a period when the determination unit determines that the luminance value is lower than the threshold value. 2. The electronic processing apparatus according to claim 1, further comprising: causing the image processing unit to output normal observation image data for displaying an image of the subject illuminated with the white light to the external device. 3. Endoscopic processor. The temporary processing control unit has the white light and the excitation light on the incident end surface of the light guide with respect to the light source only during a period when the determination unit determines that the luminance value is lower than the threshold value. Are alternately incident, and an image including the image of the subject illuminated with the white light and the image of the subject that emits fluorescence when irradiated with the excitation light is displayed on the image processing unit. The processor for an electronic endoscope according to claim 1, wherein the image data is output to the external device. The determination unit determines whether or not a luminance value selected from the luminance values constituting the red component of the fluorescence observation image data acquired by the image data acquisition unit is below a predetermined threshold value. The processor for electronic endoscopes according to claim 1, 2, or 3. The determination unit selects an intermediate luminance value in order of magnitude from the luminance values constituting the red component, and determines whether or not the selected luminance value is below a predetermined threshold value. The processor for an electronic endoscope according to claim 4. In the determination unit, a luminance value selected from luminance values constituting luminance components calculated by color space conversion from all components of the fluorescence observation image data acquired by the image data acquisition unit is a predetermined threshold value. 4. The processor for electronic endoscope according to claim 1, wherein it is determined whether or not the value is less than. The determination unit selects a predetermined brightness value in ascending order of magnitude from the brightness values constituting the brightness component, and determines whether or not the selected brightness value is below a predetermined threshold value. The processor for an electronic endoscope according to claim 6, wherein the processor is an electronic endoscope. An electronic endoscope having an insertion portion to be inserted into the body cavity of the subject is detachably mounted, and image data obtained by imaging a subject facing the distal end of the insertion portion is input to the electronic endoscope An endoscope processor,
White light for illuminating the subject and excitation light for exciting the living tissue are directed toward the incident end surface of the light guide that is passed through the insertion portion and has an emission end surface disposed at the distal end of the insertion portion. Light source part to be introduced selectively,
During the period in which the light source unit introduces the white light to the incident end face of the light guide, image data input from the electronic endoscope is acquired as normal observation image data, and the light source unit is incident on the light guide. In a period in which the excitation light is introduced into the end face, an image data acquisition unit that acquires image data input from the electronic endoscope as fluorescence observation image data;
An image processing unit that performs predetermined processing on the image data acquired by the image data acquisition unit and outputs the processed image data to an external device;
In one of the one or more operation modes, the white light is periodically incident on the light source unit on the incident end surface of the light guide for a short period, and the excitation is performed in other periods. An operation control unit that causes light to continuously enter and causes the image processing unit to process only the fluorescence observation image data of the image data acquired by the image data acquisition unit;
In the operation mode, a determination unit that determines whether a luminance value selected from the luminance values constituting the red component of the normal observation image data acquired by the image data acquisition unit exceeds a predetermined threshold value,
During the period when the determination unit determines that the luminance value exceeds the threshold, the white light is incident on the light guide unit at least periodically on the incident end surface of the light guide, and the image processing is performed. An electronic endoscope processor, comprising: a temporary processing control unit that outputs to the external device image data for displaying an image including an image of the subject illuminated with the white light. .