JP2005021580A - Fluorescent endoscope system and light source device for fluorescent endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent endoscope system capable of displaying a normal observation image and a fluorescent image on a monitor even if a system scale is small. <P>SOLUTION: White light emitted from a lamp 30 is incident to a light guide 21 of an electronic endoscope 11. In a table 36, a rotating wheel 34 rotationally driven with an exciting light transmission filter, a reference light transmission filter and white glass circumferentially fitted therein is inserted between a converging lens 33 and a light guide 21 in a normal observation mode and retreated in a fluorescent mode. An image of a subject irradiated with these light is picked up by an imaging element 20. In the fluorescent mode, the luminance values of image signals outputted during the irradiation of exciting light, and the luminance values of image signals outputted during the irradiation of reference light, are compared for every picture element, and the picture element with the ratio of both values being a prescribed value or more is specified as a lesion part, and the specific element in the image signal outputted during the irradiation of white light is changed to show a specific color and outputted to a monitor 15. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fluorescence observation endoscope system that images a body cavity of a subject based on autofluorescence emitted from a living body and outputs a video signal indicating a lesion site, and such a fluorescence observation endoscope. The present invention relates to a light source device for a fluorescence observation endoscope used together with an endoscope in a system.

  It is known that when a living body is irradiated with excitation light having a specific wavelength, fluorescence is emitted from the living body (this fluorescence is called “autofluorescence”). In addition, the intensity of autofluorescence (especially the intensity of the green light region) is lower when it is generated from a living tissue (tumor, cancer) than from normal tissue. It is also known that a lesioned part containing a dark spot is displayed darker than a normal part consisting only of normal tissue.

  Based on such knowledge, there has been proposed an autofluorescence observation apparatus that images autofluorescence of a living body through an endoscope and displays a fluorescence observation image used for diagnosis of whether the living body is normal or abnormal. ing. For example, the conventional fluorescence observation endoscope system shown in FIG. 5 processes a video signal output from a conventional endoscope (electronic endoscope) and a light source processor device (electronic endoscope) to generate a video signal. The light source device provided with a processor for outputting as a light source) can be used for fluorescence observation.

  In FIG. 5, the fluorescence endoscope system 1 includes an electronic endoscope 111 having a general hardware configuration, a light source processor 112 and a monitor 115, and a fiber probe 110 inserted through a forceps channel 111a of the electronic endoscope 111. The excitation light in the ultraviolet band and the reference light in the visible band are alternately introduced into the base end face of the fiber probe 110, and image processing is performed on the video signal obtained from the light source processor unit 112 in synchronization with the introduction of these lights. A light source device 113 that outputs a fluorescence observation video signal indicating a lesion site, a video signal output from the light source processor device 112 (a normal observation video signal that is a color video signal representing a normal visible observation image), and a light source device 113. Select one of the video signals (fluorescence observation video signal) output from the monitor 11 Are connected to the video selector 114, the light source processor 112, the light source device 113, and the video selector 114, and are operated by an operator to change the operation mode of the fluorescence endoscope system to “normal observation mode” or “fluorescence”. And an image switching signal input unit 116 for switching to “observation mode”.

  The electronic endoscope 111 includes a body cavity insertion portion 111b constituted by a flexible tube for insertion into a body cavity of a subject, an operation portion 111c attached to the proximal end of the body cavity insertion portion 111b, and The light guide flexible tube 111d extends from the side surface of the operation portion 111c. The objective lens 117 and the light distribution lens 118 are fitted into the distal end surface of the body cavity insertion portion 111b, and the distal end of the forceps channel 111a is opened. An excitation light cut filter 119 and an image sensor (monochrome CCD) 120 are incorporated in order from the objective lens 117 side inside the objective lens 117 in the body cavity insertion portion 111b. Similarly, the tip of a light guide (fiber bundle) 121 is arranged inside the light distribution lens 118. The signal line 122 for transmitting the video signal output from the image sensor 120 and the light guide 121 are both from the body cavity insertion portion 111b to the proximal end of the light guide flexible tube 111d via the operation portion 111c. Has reached. Further, a forceps port 111e which is a proximal end side opening of the forceps channel 111a described above is provided on the other side surface of the operation portion 111c.

  A socket (not shown) on which the base end of the light guide flexible tube 111d of the electronic endoscope 111 is detachably mounted is provided on the housing side surface of the light source processor device 112.

  In the light source processor unit 112, the RGB rotation wheel 123, the condensing lens 124, and the like in order along the extension of the central axis of the light guide 121 in the light guide flexible tube 111d attached to the socket. An infrared cut filter 125 and a light source 126 are arranged. The light source 126 includes a lamp that emits white illumination light when supplied with driving power from the power supply circuit 127 and a spheroid reflector that reflects the illumination light as parallel light. The infrared cut filter 125 is an optical filter for removing infrared band components from the illumination light emitted from the light source 126. The condensing lens 124 is a lens for converging illumination light traveling as parallel light on the base end surface of the light guide 121. The RGB rotating wheel is a disc in which fan-shaped red, green, and blue color filters each having a central angle of 120 degrees are fitted on the same circumference, and each motor is supplied with a current from a driver circuit 128. The filter is rotationally driven so as to be sequentially inserted into the optical path of the illumination light.

  Further, the light source processor unit 112 is connected to the first-stage signal circuit 129 that is electrically connected to the image sensor 120 via the signal line 122 when the light guide flexible tube 111d is attached to the socket. The video signal processing circuit 130 and the system control unit 131 connected to the power supply circuit 127, the first stage signal processing circuit 129, and the video signal processing circuit 130, respectively, are incorporated. The first-stage signal processing circuit 129 is a circuit that performs processing such as A / D conversion and γ correction on the video signal input from the image sensor 120. The video signal processing circuit 130 is composed of RGB color signals based on the three-field video signals input from the first-stage signal processing circuit 129 during the period in which red light, green light, and blue light are respectively incident on the light guide 121. This is a circuit that synthesizes a video signal (normal observation video signal), converts it into a format required by the monitor 115, and outputs it. The system control unit 131 is a circuit that operates in synchronization with each other by sending timing signals to the circuits 127 to 130. When the “fluorescence observation mode” is instructed from the light source device 113, the system control unit 131 stops the power supply to the light source 126 with respect to the power supply circuit 127, and Firmware that causes the power supply circuit 127 to supply power to the light source 126 when the “normal observation mode” is instructed is transferred to the light source device 113 as it is before processing, and additionally installed in advance. .

  The fiber probe 110 has a structure in which a large number of quartz glass fibers (or plastic fibers) are bundled and covered with a silicon tube, and has a total length sufficiently longer than the length of the forceps channel 111a. The proximal end of the fiber probe 110 is inserted and fixed in the light source device 113.

  In the light source device 113, a shutter 133 and a condensing lens 134 are arranged in order along the extension of the central axis of the fiber probe 110 fixed as described above. On the optical axis of the condensing lens 134, a first light beam parallel to the reference light reflecting mirror 135, the first rotary shutter 136, and the reference light reflecting mirror 135, which is further inclined by 45 degrees with respect to the optical axis. Reflective mirrors 137 are arranged in order. On the optical axis bent by the first total reflection mirror 137, the excitation light transmission filter 141 and the excitation light reflection mirror 142 are arranged in order. On the other hand, the second rotary shutter 138 and the second total reflection mirror 139 parallel to the reference light reflection mirror 135 are arranged in order on the optical axis that is bent 90 degrees by the reference light reflection mirror 135. On the optical axis bent by the second reflection mirror 139, the reference light transmission filter 140, the excitation light reflection mirror 142, the collimator lens 143, the lamp 144, and the reflector 145 are arranged in order. The lamp 144 emits white light when power is supplied by the power supply circuit 150. The reflector 145 is a hemispherical mirror that folds the light beam emitted backward from the lamp 144 by 180 degrees. The collimator lens 143 is a lens that converts a light beam emitted forward from the lamp 144 and a light beam returned by the reflector 145 into a parallel light beam. The excitation light reflecting mirror 142 is a dichroic mirror that transmits the visible light component in the parallel light beam (that is, white illumination light) emitted from the collimator lens 143 and reflects the ultraviolet light component. The excitation light transmission filter 141 is a filter that transmits only a wavelength region component (excitation light) appropriate for generating autofluorescence from the light reflected by the excitation light reflection mirror 142. The first rotary shutter 136 is a rotary shutter that allows excitation light to pass intermittently every ½ period. On the other hand, the reference light transmission filter 140 is a filter that transmits only the red light component (reference light) from the white illumination light transmitted through the excitation light reflection mirror 142. The second rotary shutter 138 is a rotary shutter that allows the reference light to pass intermittently every ½ period. The reference light reflecting mirror 135 is a dichroic mirror that transmits excitation light and reflects reference light. The condensing lens 134 is a lens that condenses the excitation light and the reference light incident as parallel light on the base end face of the fiber probe 110, respectively. The shutter 133 is selectively cut off from the excitation light and the reference light to the fiber probe 110 by being inserted into and removed from the optical path between the condenser lens 134 and the fiber probe 110 by the solenoid 146. The first rotary shutter 136 and the second rotary shutter 138 described above are driven by the driver circuit 147 so as to rotate synchronously with a phase difference shifted by 180 degrees from each other.

  The power supply circuit 150, solenoid 146, and driver circuit 147 are each connected to the system control unit 148. The system control unit 148 is further connected to the image processing circuit 149, the image switching signal input unit 116, and the system control unit 131 of the light source processor device 112. The system control unit 148 transfers the operation mode switching instruction from the image switching signal input unit 116 to the system control unit 131 of the light source processor device 112 and, when the “normal observation mode” is instructed, the solenoid 146 On the other hand, when the “fluorescence observation mode” is instructed by inserting the shutter 133 into the optical path to block the excitation light and the reference light, the solenoid 146 is retracted from the optical path and the excitation light and the reference light are retracted. Is input to the fiber probe 110 and the video signal received from the light source processor device 112 is transferred to the image processing unit 149 to perform image processing. The image processing unit 149 compares the luminance values of the video signal received while the reference light is incident on the fiber probe 110 and the video signal received while the excitation light is incident, for each pixel. A video signal (fluorescence observation video signal) in which all pixels having a ratio exceeding a predetermined value are expressed in a specific color is generated, converted into a format required by the monitor 115, and output.

  The video selector 114 is connected to the video signal processing circuit 130 of the light source processor device 112, the image processing unit 149 of the light source device 113, and the image switching signal input unit 116, and the “normal observation mode” is instructed from the image switching signal input unit 116. The normal observation video signal output from the video signal processing circuit 130 of the light source processor device 112 is selected and transmitted to the monitor 115. When the “fluorescence observation mode” is instructed, the image processing unit of the light source device 113 is selected. The fluorescence observation video signal output from 149 is selected and transmitted to the monitor 115.

  The monitor 115 displays a color image (normal observation image) based on the transmitted normal observation video signal or a monochrome image (autofluorescence image) based on the fluorescence observation video signal.

The conventional fluorescence observation endoscope system as described above is also disclosed, for example, in Patent Document 1 below.
Special table 2002-535025 gazette

  However, in the conventional fluorescence observation endoscope system described above, in addition to the electronic endoscope 111, the light source processor device 112, and the monitor 15 that are used during normal observation, the light source device 113, the fiber probe 110, and the image switching signal input unit. 116 and the video selector 114 are necessary, and there is a problem that the scale of the entire system increases. This is the first problem in the prior art.

  Further, in the above-described conventional fluorescence observation endoscope system, the normal observation image and the autofluorescence image are selectively displayed on the monitor 15, and the autofluorescence image is monochrome and includes only the lesion site. Since it is only shown, it was not possible to visually indicate which part of the body cavity the lesion site displayed. This is the second problem in the prior art.

  In view of the first problem in the prior art, a first problem of the present invention is a fluorescence observation endoscope system capable of displaying a normal observation image and a fluorescence observation image on a monitor even if the system scale is smaller than the conventional one. A light source device for a fluorescence observation endoscope is provided.

  In addition, the second problem of the present invention is that a fluorescence observation endoscope system and a fluorescence observation interior that can intuitively indicate the position of a lesion site by displaying an autofluorescence image superimposed on a normal observation image that is a color image. A light source device for an endoscope is provided.

  The present invention employs the following configuration in order to solve the first and second problems.

  That is, the endoscope used in the fluorescence observation endoscope system according to the present invention converges the light from the proximal end surface and the light guide that irradiates the subject from the distal end surface toward the subject, and the light from the subject. An objective optical system that forms an image of the subject, and a color imaging device that captures a color image of the image formed by the objective optical system and outputs a video signal.

  The light source device used in the fluorescence observation endoscope system according to the present invention and the light source device for fluorescence observation endoscope according to the present invention include a light source that emits white light, and light emitted from the light source. A condensing optical system that condenses light toward the base end surface, and excitation in a wavelength band that can excite living tissue and emit fluorescence with respect to the optical path of the light between the light source and the base end surface of the light guide A filter device that selectively inserts an excitation light transmission filter that transmits only light and a reference light transmission filter that transmits reference light in the red band, and reception that receives a video signal output from the imaging device An image processing unit that performs image processing on the video signal received by the receiving unit and converts the image signal into a video signal, and outputs the video signal converted by the image processing unit When the operation unit is operated so as to switch the operation mode to the first mode, white light is always incident on the base end surface of the light guide. And controlling the filter device to control the image processing unit to convert the video signal received by the receiving unit into a video signal, and switching the operation mode to the second mode. When operated, the filter device is controlled so that excitation light, reference light, and white light are sequentially incident on the proximal end surface of the light guide, and the excitation light is incident on the proximal end surface of the light guide. When the brightness value of the video signal received by the receiving unit and the reference light are incident on the base end surface of the light guide, The luminance value of the video signal received by the pixel is compared for each pixel, the pixel whose ratio exceeds the predetermined value is specified, and the white light is incident on the base end surface of the light guide, the receiving unit A control unit that controls the image processing unit so as to change the color of the specified pixel in the video signal received by the video signal and convert the video signal after the change into a video signal. To do.

  If comprised in this way, if an operation part is operated and it switches to 1st mode, a control apparatus will control the said filter apparatus so that white light may always inject into the base end surface of the said light guide. Then, the filter device retracts both the excitation light transmission filter and the reference light transmission filter from the optical path. As a result, white light emitted from the light source enters the light guide and is irradiated onto the subject. At this time, the image of the subject formed by the objective optical system is a color image by reflected light of white light. At the same time, the control unit controls the image processing unit so as to convert a video signal output from the image sensor that has captured the image and received by the receiving unit into a video signal. As a result, a normal observation image (color image) of the subject is displayed on the monitor by this video signal. Next, when the operation unit is operated to switch to the second mode, the control device controls the filter device so that excitation light, reference light, and white light are sequentially incident on the base end surface of the light guide. Then, the filter device sequentially switches between a state in which only the excitation light transmission filter is inserted in the optical path, a state in which only the reference light transmission filter is inserted in the optical path, and a state in which both filters are removed from the optical path. As a result, the excitation light that has passed through the excitation light transmission filter, the reference light that has passed through the reference light transmission filter, and the white light emitted from the light source are sequentially incident on the light guide to irradiate the subject. During this time, the image formed by the objective optical system is an image of the subject by fluorescence, a monochromatic image by reflected light of the reference light, and a color image by reflected light of white light. At the same time, the control unit has the luminance value of the video signal received by the receiving unit and the reference light incident on the proximal end surface of the light guide when the excitation light is incident on the proximal end surface of the light guide. Sometimes the luminance value of the video signal received by the receiving unit is compared for each pixel, a pixel whose ratio exceeds a predetermined value is specified, and the white light is incident on the base end face of the light guide Sometimes the image processing unit is controlled to change the color of the specified pixel in the video signal received by the receiving unit and convert the changed video signal into a video signal. As a result, the video signal displays a fluorescence observation image in which the lesion site is indicated by a specific color in the color image of the subject on the monitor, so that the operator knows the location of the lesion site intuitively. be able to.

  According to the present invention, in addition to the light source device (fluorescence observation endoscope light source device) having the above-described configuration, a light source device that emits excitation light, a fiber probe, and an image processing device for combining fluorescence observation images are provided. Since it is not necessary to prepare, the whole system becomes simple and small-scale.

  According to the fluorescence observation endoscope system and the light source device for fluorescence observation endoscope of the present invention configured as described above, the normal observation image and the fluorescence observation image are displayed on the monitor even if the system scale is smaller than the conventional system. In addition, the position of the lesion site can be intuitively indicated by displaying the autofluorescence image superimposed on the normal observation image which is a color image.

  The best mode for carrying out a fluorescence observation endoscope system and a fluorescence observation endoscope light source device according to the present invention will be described below with reference to the drawings.

[Configuration of electronic endoscope device]
FIG. 1 is a schematic configuration diagram of a fluorescence observation endoscope system 10 according to the present embodiment. In FIG. 1, a fluorescence observation endoscope system 10 includes an electronic endoscope 11 that is a kind of endoscope, a light source processor device 12 connected to the electronic endoscope 11, and a connection to the light source processor device 12. The monitor 15 and the image switching signal input unit 16 are configured. Hereinafter, each of these devices will be described individually.

  The image switching signal input unit 16 is operated by an operator to switch a switching signal for switching the operation mode of the fluorescence observation endoscope system 10 to the normal observation mode (first mode) or the fluorescence observation mode (second mode). , Input to the light source processor device 12 (the system control circuit 28 described later).

  The electronic endoscope 11 is schematically shown in FIG. 1 to show its internal configuration. However, the electronic endoscope 11 is inserted into the body cavity of the subject, and the proximal end of the body cavity insertion part 11a is inserted into the body cavity. The light guide flexible tube 11c extends from the side of the operation portion 11b, and the connector 11d attached to the tip of the light guide flexible tube 11c.

  The distal end of the body cavity insertion portion 11a has at least two through holes, one of which is a light distribution lens 17 made of a negative lens, and the other is an objective lens group having a positive power. Each of the optical systems 18 is fitted. In the body cavity insertion portion 11, an image pickup device (color CCD, that is, a color CCD) that captures a real image of the test object at a position separated by a predetermined working distance in front of the objective optical system 18 is obtained. , A color imaging device) 20 is disposed. Further, an excitation light cut filter 19 for blocking ultraviolet band light is disposed between the objective optical system 18 and the image sensor 20.

  The distal end portion of the body cavity insertion portion 11a (the location where the image sensor 20 is accommodated) is made of a hard member, but the portion closer to the operation portion 11b is more flexible. It has a structure. Furthermore, the range of the predetermined length on the distal end side of the flexible portion is a large number of segments (not shown) connected to each other so as to be tiltable about an axis orthogonal to the central axis of the body cavity insertion portion 11a. Is configured as a curved portion in which is incorporated.

  In the operation part 11b, the bending part is bent at an arbitrary angle in an arbitrary direction by selectively drawing a plurality of (2 or 4) wires having their tips attached to the foremost segment of the bending part. A knob (not shown) is provided. Further, on the other side surface of the operation portion 11b, there is provided a forceps port 11f that communicates with a forceps channel 11e that is drawn through the body cavity insertion portion 11a and opens at the distal end surface thereof.

  In order to guide the light incident by the light source processor device 12 in the conduit from the distal end of the body cavity insertion portion 11a to the connector 11d through the operation portion 11b and the light guide flexible tube 11c as described later. A video signal line that transmits a light guide fiber bundle (hereinafter referred to as “light guide”) 21 and a video signal output from the image sensor 20 (analog signal representing luminance values of RGB colors for each pixel) to the light source processor device 12. 22 are respectively passed through. Note that the exit end of the light guide 21 is at a position where the illumination light emitted from the light guide 21 is diverged through the light distribution lens 17 at a light distribution angle slightly larger than the angle of view by the objective optical system 18 and the image sensor 20. It has been fixed.

  An incident end of the light guide 21 protrudes vertically and is fixed to the distal end surface of the connector 11d, and an electrical connector comprising a large number of electrodes respectively conducting to the video signal line 22 and various signal lines (not shown). (Not shown) is provided.

  On the side surface of the housing of the light source processor device 12, a connector receiver 12a into which the tip of the connector 11d of the electronic endoscope 11 is fitted is formed. In the connector receiver 12a, when the connector 11d is attached to the connector receiver 12a, there are sockets made up of a number of electrodes that contact various electrodes in the electrical connector (not shown), and the base end of the light guide 21. A holding hole to be inserted is provided.

  In the light source processor device 12, the front-stage signal processing circuit 23, the memory 24 connected to the front-stage video signal processing circuit 23, the arithmetic processing circuit 25 connected to the memory 24, and the arithmetic processing circuit 25 The connected post-stage video signal processing circuit 26, the memory 24, the arithmetic processing circuit 25, and the system control circuit 28 connected to the post-stage signal processing circuit 26, the pre-stage signal processing circuit 23, and the driver connected to the system control circuit 28, respectively. A circuit 27, a first motor 35, a second motor 37 and a diaphragm 32 further connected to the driver circuit 27, and a lamp power source 29 further connected to the system control circuit 28 are incorporated as main electrical components. When the connector 11 d of the electronic endoscope 11 is attached to the connector receiver 12 a of the light source processor device 12, the image sensor 20 is connected to the pre-stage signal processing circuit 23 through the video signal line 22. Further, the image control signal input unit 16 is connected to the system control circuit 28, and the monitor 15 is connected to the subsequent signal processing circuit 26.

  Further, in the light source processor device 12, a rotating wheel 34 and a condensing lens that are rotated by the first motor 35 described above along the extension line of the light guide 21 protruding from the connector 11d mounted on the connector receiver 12a. 33, the above-described diaphragm 32, the infrared light cut filter 31, and the lamp 30 to which driving power is supplied by the above-described lamp power source 29 are incorporated. The first motor 35 described above can be moved in a direction orthogonal to the optical axis of the condenser lens 33 by the table 36 driven by the second motor 37 described above.

  The system control circuit 28 serving as a control unit supplies driving power for turning on the lamp 30 to the lamp power source 29, and performs each operation according to the operation mode (normal observation mode, fluorescence observation mode) designated by the image switching signal input unit 16. The operation of the block (memory 24, arithmetic processing circuit 25, subsequent signal processing circuit 26, driver circuit 27) is controlled.

  The lamp 30 as a light source is composed of a light bulb that emits light by electric power supplied from a lamp power source 29 and a reflector that reflects illumination light (white light) emitted from the light bulb as parallel light.

  The infrared light cut filter 31 is an optical filter that blocks only the infrared band component from the illumination light emitted as parallel light from the lamp 30.

  The diaphragm 32 is a device that changes the aperture area (that is, the cross-sectional area of the optical path of the illumination light) in accordance with a signal supplied from the driver circuit 27. Note that the driver circuit 27 is configured so that the luminance value (average luminance value or peak luminance value) of the video signal output from the image sensor becomes constant based on the luminance value of the video signal notified from the preceding signal processing circuit 23. In addition, the diaphragm 32 is driven to adjust the amount of illumination light (that is, the cross-sectional area of the optical path of the illumination light).

  The condensing lens 33 as a condensing optical system condenses the incident light that has passed through the diaphragm 32 on the base end face of the light guide 21 and makes it incident.

  The first motor 35 is fixed on the moving table 36 with its drive shaft directed in a direction parallel to the optical axis of the condenser lens 33. The moving table 36 is driven by a second motor 37 and is moved to the first position close to the optical axis of the condenser lens 33 in the fluorescence observation mode, and to the second position separated from the optical axis in the normal observation mode. The first motor 35 is moved in the direction perpendicular to the optical axis. The moving table 36 and the second motor 37 correspond to a moving mechanism.

  The rotating wheel 34 fixed to the drive shaft of the first motor 35 enters the optical path of the illumination light when the first motor 35 is present at the first position, and the motor 35 is present at the second position. And an outer diameter that can be retracted from the optical path. As shown in the front view of FIG. 2, when the first motor 35 is in the first position, the optical path of the illuminating light is relative to the rotating wheel 34 as the rotating wheel 34 rotates. A fan-shaped excitation light transmission filter 34a having a central angle of 180 degrees, a fan-shaped reference light transmission filter 34b having a central angle of 45 degrees, and a fan-shaped white glass having a central angle of 135 degrees along the trajectory passing through White light passing portions) 34c are respectively fitted. As shown in the transmission characteristic graph of FIG. 3, the excitation light transmission filter 34a has a characteristic of transmitting only light in the ultraviolet band (that is, excitation light), and the reference light filter 34b is light in the red band. (That is, it has a characteristic of transmitting only the reference light). Therefore, in the fluorescence observation mode, the first motor 35 is rotated by the driver circuit 27, so that the excitation light is incident on the light guide 21 only for a half period during the period in which the rotating wheel 34 rotates once. , The reference light is incident on the light guide 21 only for a period of 1/8, and the white illumination light is incident on the light guide 21 for the remaining 3/8 period. Since the driver circuit 27 rotates the first motor 35 in accordance with the timing signal received from the system control circuit 28, the system control circuit 28 determines which filter 34a, 34b or white glass 34c is currently used for the illumination light. It recognizes whether it is inserted in the optical path (that is, what light is incident on the light guide 21). The driver circuit 27, the rotating wheel 34, the first motor 35, the moving table 36, and the second motor 37 correspond to a filter device.

  The pre-stage signal processing circuit 23 as a receiving unit receives the video signal input from the image sensor 20 through the image signal line 22, changes the format from an analog signal to a digital signal, and performs processing such as γ correction. Output. As described above, the pre-stage signal processing circuit 23 notifies the driver circuit 27 of the luminance value (average luminance value or peak luminance value) extracted from the video signal for one field input from the image sensor 20.

  As shown in the detailed block diagram of FIG. 4, the memory 24 includes a normal white light image memory 24a, an autofluorescence image memory 24b, and a reference light image memory 24c. The normal white light image memory 24a is a memory area in which video signals for all the pixels on the image sensor 20 (pixels constituting all light receiving surfaces covered with filters of red, green and blue colors) are stored. is there. The self-fluorescent image memory 24b is a memory area in which video signals for all pixels corresponding to green on the image sensor 20 (all pixels covered with a green filter distributed over the entire light receiving surface) are accumulated. The reference light image memory 24c is a memory area in which video signals for all pixels corresponding to red on the image sensor 20 (all pixels covered with a red filter distributed over the entire light receiving surface) are accumulated. Further, in the memory 24, the transmission path of the video signal input from the preceding signal processing circuit 23 is switched in accordance with the timing signal input from the system control circuit 28, and transferred to any of the image memories 24a to 24c. A signal selector 24d is included.

  Specifically, the signal selector 24d transfers the video signals sequentially input from the previous stage signal processing circuit 23 to the normal white light image memory 24a in the normal observation mode according to the timing signal from the system control circuit 28. To do.

  The signal selector 24d follows the timing signal from the system control circuit 28, and in the fluorescence observation mode, when the excitation light is incident on the light guide 21, the video selector 24d sequentially inputs video signals from the pre-stage signal processing circuit 23. Is transferred to the auto-fluorescent image memory 24b, and when the reference light is incident on the light guide 21, the video signals sequentially input from the preceding signal processing circuit 23 are transferred to the reference light image memory 24c, and the white light is transmitted to the light guide. When the light is incident on the video signal 21, the video signals sequentially input from the previous signal processing circuit 23 are transferred to the normal white light image memory.

  As shown in FIG. 4, the arithmetic processing circuit 25 receives the video signal (autofluorescence video signal) read from the autofluorescence image memory 24b and the video signal (reference light video signal) read from the reference light image memory 24c. The arithmetic processing circuit 25a, the output of the arithmetic processing circuit 25a, and the video signal (normal white light video signal) read from the normal white light image memory 24a are input and the output is input to the subsequent signal processing circuit 26. An adder circuit 25b is included.

  Then, according to the timing signal from the system control circuit 28, in the normal observation mode, only the adder circuit 25b is activated to read out the normal white light video signal from the normal white light image memory 24a (the arithmetic processing circuit 25a is activated). Since the output is not input because it is not, it is input to the subsequent signal processing circuit 26 as it is.

  Further, in accordance with an instruction from the system control circuit 28, in the fluorescence observation mode, the arithmetic processing circuit 25a is activated to receive the autofluorescence video signal and the reference light video signal from the autofluorescence image memory 24b and the reference light image memory 24c, respectively. At the same time, the addition circuit 25b is activated to read the normal white light video signal from the normal white light image memory 24a. Then, the arithmetic processing circuit 25a compares the luminance value of the autofluorescence video signal with the luminance value of the reference light video signal for each pixel, and determines a pixel whose lesion ratio is greater than a predetermined value for the former as a pixel indicating a lesion site. As specified. Then, only the specified pixel outputs video data having a specific color (a predetermined combination of each luminance value of red, green and blue, for example, a combination indicating blue), and inputs it to the adding circuit 25b. The adding circuit 25b superimposes the output of the arithmetic processing circuit 25a on the autofluorescence video signal, thereby displaying the video signal (the autofluorescence image in which the lesion site is superimposed in a specific color on the normal white light image of the color). Are synthesized and sent to the subsequent signal processing circuit 26.

  The post-stage signal processing circuit 26 converts the video signals sequentially input from the arithmetic processing circuit 25 into a video signal format required by the monitor 15 and outputs the video signal to the monitor 15. These pre-stage signal processing circuit 23, memory 24, arithmetic processing circuit 25, and post-stage signal processing circuit 26 correspond to an image processing unit. Further, the post-stage signal processing circuit 26 corresponds to an output unit.

  According to the fluorescence observation endoscope system of the present embodiment configured as described above, the surgeon operates the image switching signal input unit 16 to perform normal observation on the system control circuit 28 of the light source processor device 12. A switching signal for switching to the mode (first mode) is input. Then, in response to an instruction from the system control circuit 28, the lamp power supply 29 supplies driving power to the lamp 30 to emit illumination light, and the driver circuit 27 drives the second motor 37 to rotate the rotating wheel 34. Retreat from the light path of the illumination light. Then, white illumination light is always incident on the light guide 21. In this state, the surgeon inserts the body endoscope insertion portion 11a of the electronic endoscope into the body cavity of the subject and makes the distal end face the subject (inner body wall).

  Then, an image of the subject formed by the reflected light of the white illumination light is formed by the objective optical system 18 and picked up by the image pickup device 20 and converted into a video signal (normally white light video signal). The normal video signal is subjected to predetermined processing by the pre-stage signal processing circuit 23 and stored in the normal white light image memory 24 a of the memory 24. When the normal white light video signal for one screen is accumulated on the normal white light image memory 24a, the normal white light video signal for one screen is read out and passed through the arithmetic processing circuit 25 to the subsequent signal. After being input to the processing circuit 26 and converted into a video signal, it is input to the monitor 15. As a result, the normal observation image in the body cavity of the subject imaged by the electronic endoscope 11 is displayed on the monitor 15 as a color image.

  The surgeon who sees the normal observation image operates the image switching signal input unit 16 when the subject is suspected of having a lesion, thereby observing the system control circuit 28 of the light source processor 12 with the fluorescence observation. A switching signal for switching to the mode (second mode) is input. Then, in response to an instruction from the system control circuit 28, the driver circuit 27 drives the second motor 37 to insert the rotating wheel 34 into the optical path of the illumination light, and drives the first motor 35 to rotate. The wheel 34 is rotated. Then, excitation light, reference light, and white illumination light are sequentially incident on the light guide 21.

  The living body of the subject irradiated with the excitation light through the light guide 21 and the light distribution lens 17 emits fluorescence, and this fluorescence enters the objective optical system 18 together with the reflected light of the excitation light on the surface of the subject. However, since the reflected light of the excitation light is blocked by the excitation light cut filter 19, an image of the subject by only the excitation light is formed by the objective optical system 18, and the image signal (autofluorescence image signal) is obtained by the imaging device 20. ). This self-fluorescent video signal is subjected to predetermined processing by the pre-stage signal processing circuit 23 and stored in the self-fluorescent image memory 24 b of the memory 24.

  Subsequently, when the subject is irradiated with the reference light, an image of the subject formed by the reflected light of the reference light is formed by the objective optical system 18 and picked up by the image pickup device 20, and a video signal (reference light video signal). Is converted to The reference light image signal is subjected to predetermined processing by the pre-stage signal processing circuit 23 and stored in the reference light image memory 24 c of the memory 24. Note that the irradiation time of the reference light (that is, the central angle of the reference light transmission filter 34b) is ¼ of the irradiation time of the excitation light (that is, the central angle of the excitation light transmission filter 34a) due to the excitation light. This is because the autofluorescence accumulation time needs to be relatively long because the intensity of the autofluorescence is much weaker than the intensity of the reflected light of the reference light.

  Subsequently, when the object is irradiated with white illumination light, an image of the object formed by the reflected light of the white illumination light is formed by the objective optical system 18 and picked up by the image pickup device 20, and a video signal (normally white light) Video signal). The normal white light video signal is subjected to predetermined processing by the pre-stage signal processing circuit 23 and stored in the normal white light image memory 24 a of the memory 24.

  As described above, the video signals stored in the memories 24a to 24c are read out to the arithmetic processing circuit 25a or the adding circuit 25b of the arithmetic processing circuit 25, and the fluorescence observation video signals are synthesized. The fluorescence observation video signal is input to the post-stage signal processing circuit 26, converted into a video signal, and then input to the monitor 15. As a result, an autofluorescence image in which the lesion site is indicated in a specific color on the normal observation image of the subject imaged by the electronic endoscope 11 is displayed on the monitor 15.

  As described above, according to the fluorescence observation endoscope system of the present embodiment, an image in which a fluorescence image of a lesion site is superimposed on a normal observation image of a subject is displayed. By simply looking, the position and size of the lesion site can be intuitively known. Further, according to the fluorescence observation endoscope apparatus of the present embodiment, the functions of the conventional light source processor device 112 and the light source device 113 are integrated into one light source processor device 12, and accordingly, the lamp 30 and the condenser lens 33 are combined. In addition, since the driver circuit 27 and the system control unit 28 are shared, the entire system can be simplified and downsized.

Configuration diagram of a fluorescence observation endoscope system according to an embodiment of the present invention Front view of rotating wheel Graph showing transmission characteristics of excitation light transmission filter and reference light transmission filter Block diagram showing detailed configuration of memory and arithmetic processing circuit Configuration diagram of a conventional fluorescence observation endoscope system

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fluorescence observation endoscope system 11 Electronic endoscope 12 Light source processor apparatus 15 Monitor 16 Image switching signal input part 18 Objective optical system 20 Image sensor 21 Light guide 24 Memory 25 Arithmetic processing circuit 27 Driver circuit 28 System control circuit 29 Lamp power supply 30 lamp 33 condenser lens 34 rotating wheel 35 first motor 36 table 37 second motor

Claims (4)

A fluorescence observation endoscope system comprising an endoscope and a light source device,
The endoscope is
A light guide that irradiates the subject with light incident from the proximal end surface toward the subject;
An objective optical system that focuses light from the subject to form an image of the subject;
A color imaging device that color-images an image formed by the objective optical system and outputs a video signal;
The light source device is
A light source that emits white light;
A condensing optical system that condenses the light emitted from the light source toward the base end surface of the light guide;
An excitation light transmission filter that transmits only excitation light in a wavelength band that can excite biological tissue and emit fluorescence with respect to the optical path of the light between the light source and the base end surface of the light guide; A filter device that selectively inserts a reference light transmission filter that transmits the reference light, and
A receiving unit for receiving a video signal output from the imaging device;
An image processing unit that performs image processing on the video signal received by the receiving unit and converts the image signal into a video signal;
An output unit for outputting the video signal converted by the image processing unit;
An operation unit operated to switch operation modes;
When the operation unit is operated so as to switch the operation mode to the first mode, the filter device is controlled so that white light is always incident on the base end surface of the light guide, and is received by the reception unit. When the operation unit is operated to switch the operation mode to the second mode, the excitation light, the reference light, and the white light are sequentially applied. The filter device is controlled to repeatedly enter the base end surface of the light guide, and the luminance value of the video signal received by the receiving unit when the excitation light is incident on the base end surface of the light guide and the The luminance value of the video signal received by the receiving unit when the reference light is incident on the base end face of the light guide is compared for each pixel, Identifying a pixel whose ratio exceeds a predetermined value, and changing the color of the identified pixel in the video signal received by the receiver when the white light is incident on the base end face of the light guide; A fluorescence observation endoscope system comprising: a control unit that controls the image processing unit so as to convert the video signal after the change into a video signal. The filter device is
A rotating wheel provided with a white light passage portion that allows white light emitted from the excitation light transmission filter, the reference light transmission filter, and the light source to pass through the circumferential direction as it is,
A motor that rotates this rotating wheel,
A first position for sequentially inserting the excitation light transmission filter, the reference light transmission filter, and the white light passage portion into the optical path as the rotation wheel is rotated by the motor; and a second position retracted from the optical path; And a moving mechanism that moves between
When the control unit is controlled so that white light is always incident on the base end face of the light guide, the moving mechanism moves the rotating wheel to the second position, and the control unit drives the excitation light. When the light and white light are controlled to sequentially and repeatedly enter the base end face of the light guide, the rotating wheel is moved to the first position by the moving mechanism and the rotating wheel is rotated by the motor. The fluorescence observation endoscope system according to claim 1. The image processing unit
Autofluorescence video signal received by the receiving unit when the excitation light is incident on the base end surface of the light guide, received by the receiving unit when the reference light is incident on the base end surface of the light guide Each of the reference light image signal and the normal white light image signal received by the receiving unit when the white light is incident on the base end surface of the light guide;
The luminance value of the self-fluorescent video signal read from the memory and the luminance value of the reference light video signal are compared for each pixel, and a video signal indicating a pixel whose ratio exceeds a predetermined value in a specific color An arithmetic processing circuit for outputting
The fluorescence observation endoscope system according to claim 1, further comprising: an addition circuit that superimposes the normal white light video signal read from the memory and the video signal output from the arithmetic processing circuit. A light guide for irradiating light incident from the base end surface toward the subject from the distal end surface, an objective optical system for focusing the light from the subject to form an image of the subject, and the objective optical system A light source device for a fluorescence observation endoscope that is connected to an endoscope having a color imaging device that color-shoots an imaged image and outputs a video signal,
A light source that emits white light;
A condensing optical system that condenses the light emitted from the light source toward the base end surface of the light guide;
An excitation light transmission filter that transmits only excitation light in a wavelength band that can excite biological tissue and emit fluorescence with respect to the optical path of the light between the light source and the base end surface of the light guide; A filter device that selectively inserts a reference light transmission filter that transmits the reference light, and
A receiving unit for receiving a video signal output from the imaging device;
An image processing unit that performs image processing on the video signal received by the receiving unit and converts the image signal into a video signal;
An output unit for outputting the video signal converted by the image processing unit;
An operation unit operated to switch operation modes;
When the operation unit is operated so as to switch the operation mode to the first mode, the filter device is controlled so that white light is always incident on the base end surface of the light guide, and is received by the reception unit. When the operation unit is operated to switch the operation mode to the second mode, the excitation light, the reference light, and the white light are sequentially applied. The filter device is repeatedly controlled to be incident on the base end surface of the light guide, and the luminance value of the video signal received by the receiving unit when the excitation light is incident on the base end surface of the light guide and the The luminance value of the video signal received by the receiving unit when the reference light is incident on the base end face of the light guide is compared for each pixel, Identifying a pixel whose ratio exceeds a predetermined value, and changing the color of the identified pixel in the video signal received by the receiver when the white light is incident on the base end face of the light guide; A light source device for a fluorescence observation endoscope, comprising: a control unit that controls the image processing unit so as to convert the changed video signal into a video signal.

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