JP4459710B2 - Fluorescence observation endoscope device - Google Patents

Description

  The present invention relates to a fluorescence observation endoscope apparatus that captures an image of fluorescence emitted from a living tissue of a test part by irradiating the test part with excitation light for fluorescence excitation through an endoscope.

  It is known that when a living tissue is irradiated with light of a certain wavelength band as excitation light, fluorescence is emitted from the living tissue (this fluorescence is called “autofluorescence”). Furthermore, since the intensity of autofluorescence is lower in the living body from the diseased tissue (tumor, cancer) than that from the normal tissue, when expressed as an image, the lesion site containing the diseased tissue is normal tissue. It is also known that the image is displayed darker than a normal region consisting of only.

  Based on such knowledge, a fluorescence observation endoscopic device that captures autofluorescence of a living body through an endoscope and displays a fluorescent image for diagnosis of whether the living body is normal or abnormal is proposed. Has been. Such a fluorescence observation endoscope apparatus includes a conventional endoscope (electronic endoscope) and a light source processor apparatus (a processor that processes a video signal output from the electronic endoscope and outputs it as a video signal). The light source device) is modified. Specifically, an electronic endoscope used in a fluorescence observation endoscope apparatus is a quartz glass fiber having a good transmittance for light in a blue to ultraviolet band as its light guide fiber bundle (hereinafter simply referred to as “light guide”). The excitation light cut filter for cutting the light of the specific wavelength used as excitation light is inserted in the optical path from the objective window to the image sensor. The light source processor device is configured to be able to arbitrarily switch between white light or excitation light and introduce it into the light guide of the endoscope, and when introducing white light into the light guide (hereinafter referred to as “normal observation”). Mode ”and when the excitation light is introduced into the light guide (hereinafter referred to as“ fluorescence observation mode ”), the image processing content for the video signal output from the electronic endoscope is changed. .

An operator (physician) who uses the fluorescence observation endoscope apparatus configured as described above has the light source processor device set to the normal observation mode and performs the same operation on the monitor as in the case of using the normal endoscope. While observing the image displayed on the image (that is, a normal color image obtained by the image pickup device capturing an image of white light irradiated from the distal end of the body cavity insertion portion on the surface of the body cavity inner wall) The tip of the body cavity insertion part is inserted into the body cavity of the subject. And if the site | part (test part) which is suspected of having abnormality is caught in the image, an operator will switch a light source processor apparatus to fluorescence observation mode. Then, instead of white light, excitation light is irradiated from the distal end of the body cavity insertion portion toward the test portion, and an image of the test portion only by fluorescence generated from the living tissue under the body cavity inner wall excited by the excitation light is obtained. An image (fluorescent image) formed by the objective optical system and captured by the imaging device is displayed on the monitor. In this fluorescent image, the abnormal part is dark as described above, and the part where the excitation light does not reach (for example, the back of the body cavity) is also darkly shaded. However, since the illumination light does not reach the latter part even in the normal observation mode, it should be dark even in the normal color image. Therefore, the operator compares the fluorescent image with the normal color image by temporarily switching to the normal observation mode, identifies the shadow portion of the dark portion in the fluorescent image, and if there is a dark portion that is not a shadow portion, Is identified as an abnormal site.
JP 09-131306 A

  However, since the conventional fluorescence observation endoscope apparatus having the above configuration captures an image formed by the fluorescence transmitted through the excitation light cut filter and displays the fluorescence intensity distribution in the image on the display, It was difficult to know exactly what spectrum of fluorescence was occurring.

  In this regard, a fiber probe is inserted through the forceps channel normally provided in an endoscope to the distal end of the body cavity insertion portion, and the fluorescence is guided to the spectrometer through the fiber probe. A light probe type fluorescence endoscope system for measurement is already in practical use.

  However, according to this light probe type fluorescence endoscope system, the tip of the light probe protruding from the tip of the forceps channel and the objective optical system incorporated in the tip of the body cavity insertion portion are the tip of the body cavity insertion portion. There is a problem in that it is difficult to bring the tip of the light probe into contact with the test portion accurately because it is displaced in the plane. In other words, the surgeon performs an operation to bring the tip of the light probe closer to the test portion while viewing the image captured through the objective optical system. While imaging this image, the operator looks at the tip of the light probe from an oblique front. I can't figure out where the axis of this light probe tip is. For this reason, it is difficult to accurately contact the tip of the light probe with the target test portion. Moreover, in order to stably hold the tip of the light probe, it is necessary to reduce the protrusion amount of the light probe from the forceps channel as much as possible, but if the protrusion amount of the light probe is reduced in this way, There is also a problem that the tip of the lens becomes out of view of the objective optical system and the image sensor and is completely invisible.

  Accordingly, an object of the present invention is to allow an object of fluorescence spectroscopy measurement to be observed through the optical system for fluorescence spectroscopy measurement, so that the optical system for fluorescence spectroscopy measurement can be accurately and easily measured. It is intended to provide a fluorescence endoscope apparatus that can be guided to and brought into contact with.

  The fluorescence observation endoscope apparatus according to the present invention devised to solve the above-described problems irradiates a test part in a body cavity with excitation light, and a living tissue of the test part excited by the excitation light is emitted. A fluorescence observation endoscope apparatus that captures an image of fluorescence with an endoscope, and includes an imaging optical system at a tip thereof, and an image of a test part formed on the tip surface by the imaging optical system. An endoscope with a built-in fiber bundle that transmits to the base end face, an excitation light source that emits excitation light, and an optical system that guides the excitation light emitted from the excitation light source to the base end face of the fiber bundle. An excitation light optical system including a condensing lens for converging light on the end face of the fiber bundle, and a light beam emitted from the end face of the fiber bundle, disposed between the end face of the fiber bundle and the condensing lens. A first separation optical element that separates from the optical path of the optical fiber, and a re-image that re-images the image transmitted to the base end face of the fiber bundle by converging the light beam separated by the first separation optical element An optical system, an imaging element that captures an image re-imaged by the re-imaging optical system, and the first separation optical element and the imaging element, and the first separation optical element A second separation optical element for further separating the separated light beam; a spectroscope for spectroscopic measurement of the light beam separated by the second separation optical element; the first separation optical element; the imaging optical element; And a filter unit disposed between the spectroscope and blocking light in the same wavelength band as the excitation light.

  When configured in this way, the excitation light emitted from the excitation light source is guided to the base end surface of the fiber bundle in the endoscope through the excitation light optical system, and is converged by the condensing lens. It is incident on the base end face of. The fiber bundle emits excitation light incident from the base end face thereof from the front end face. Then, the imaging optical system irradiates the test part with this excitation light. The fluorescence emitted from the living tissue of the test part irradiated with the excitation light is incident on the re-imaging optical system of the endoscope, thereby forming an image of the test part on the tip surface of the fiber bundle. This image is transmitted to the base end face by the fiber bundle and reproduced on the base end face. The fluorescence that forms the image emitted from the base end face is separated from the optical path of the excitation light by the first separation optical element, and further separated by the second separation optical element. One of the fluorescence separated by the second separation optical element re-images the image appearing on the base end face of the fiber bundle on the image pickup surface of the image pickup element by the re-imaging optical system. This image is captured by this image sensor. The other of the fluorescence separated by the second separation optical system is re-imaged by the spectrometer. Therefore, the center of the image displayed by the image signal obtained by the image pickup device picking up an image coincides with the extension line of the optical axis of the imaging optical system. Therefore, the operator can easily examine the optical axis of the imaging optical system if he / she operates the endoscope so that the center of the subject is captured at the center of the subject while viewing this image. The center of the part can be contacted. Moreover, since the light beam forming the image picked up by the image sensor is equivalent to the light beam incident on the spectroscope, the surgeon can always recognize the object being spectroscopically measured by the spectroscope.

  As described above, according to the fluorescence observation endoscope apparatus of the present invention, an object of fluorescence spectrometry can be observed through the optical system for fluorescence spectroscopy, and thus Therefore, it is possible to accurately and easily guide the optical system to the object to be measured.

  Next, modes for carrying out the present invention will be described based on the attached drawings.

  FIG. 1 is an external view of an endoscope system that is an embodiment of a fluorescence observation endoscope apparatus according to the present invention. As shown in FIG. 1, the endoscope system includes a fluorescence observation endoscope 10, a light source processor device 20, and a monitor 60.

  The fluorescence observation endoscope 10 is obtained by adding a modification for fluorescence observation to a normal electronic endoscope. As shown in FIG. 3, the insertion into a body cavity is formed to be elongated in order to be inserted into a body cavity. A light guide flexible tube 10e for connecting the operation portion 10b and the light source processor device 20; an operation portion 10b having an angle knob for bending the distal end portion of the body cavity insertion portion 10a; A connector 10d provided at the base end of the light guide flexible tube 10e is provided.

  As shown in the schematic diagram of FIG. 2, a first imaging lens (corresponding to an imaging optical system) 11 and a second imaging lens (corresponding to an objective optical system) 12 are provided on the distal end surface of the body cavity insertion portion 10a. Each is fitted. An imaging element 13 that captures an image of a subject formed by the second imaging lens 12 along the optical axis of the second imaging lens 12 is incorporated in the body cavity insertion portion 10a. ing. The image pickup device 13 is a color solid-state image pickup device (color CCD) in which a mosaic filter is covered on the image pickup surface. Excitation that blocks light in a predetermined wavelength band (light having a wavelength corresponding to excitation light 1 to be described later) from the light beam emitted from the second imaging lens 12 between the second imaging lens 12 and the image sensor 13. An optical cut filter 14 is inserted.

  A signal cable 18 for transmitting a video signal output from the imaging device 13 is provided on the end surface of the connector 10d through the body cavity insertion portion 10a, the operation portion 10b, and the light guide flexible tube 10e. It is connected to the electrical connector 17.

  In parallel with the signal cable 18, the body cavity insertion portion 10a, the operation portion 10b, and the light guide flexible tube 10e are composed of a CFB (coherent fiber bundle, that is, an optical fiber excellent in laser light transmission). The fiber bundle 16 in which the arrangement order of the optical fibers at the both ends completely coincides with each other. The distal end of the CFB 16 faces the first imaging lens 11 in the distal end portion of the body cavity insertion portion 10a, and the proximal end thereof is inserted and fixed in a metal pipe 19 protruding from the end face of the connector 10d. Yes.

  The first imaging lens 11 is a positive lens having a shorter focal length than the second imaging lens 12. Therefore, the light emitted from the front end surface of the CFB 16 is refracted by the first imaging lens 11 and is more than the working distance of the second imaging lens 12 (that is, the position where the test portion is to be placed in normal observation). An image of the front end surface of the CFB 16 is once formed in front, and is irradiated on the entire imaging range by the second imaging lens 12 and the image sensor 13 at the working distance of the second imaging lens 12. On the contrary, the light emitted from the subject arranged at the working distance of the first imaging 11 is refracted by the first imaging lens 11 and forms an image of the subject on the front end surface of the CFB 16. This subject image is transmitted by the CFB 16 and reproduced on the base end surface of the CFB 16.

  The light source processor device 20 is detachably connected to the fluorescence observation endoscope 10, and selectively irradiates illumination light (white light) and laser light to the proximal end surface of the CFB 16 of the connected fluorescence observation endoscope 10. Then, image processing is performed on the video signal received from the image sensor 13 through the electrical connector 17 of the fluorescence observation endoscope 10, and further, an image reproduced on the base end face of the CFB 16 is captured and converted into a video signal, and the spectrum is obtained. This is a device that generates a spectral signal by measurement, performs image processing on the obtained video signal and spectral signal, and synthesizes a video signal output to the monitor 60.

  The front panel of the casing of the light source processor device 20 is a cylinder into which the pipe 19 of the fluorescence observation endoscope 10 is inserted from the outer surface side when the fluorescence observation endoscope 10 is detachably connected. A socket 20a is provided. The through hole formed in the socket 20a communicates with the internal space of the light source processor device 20. In the inner space of the light source processor device 20, the first beam splitters 22 and 22 are sequentially arranged along the extension line of the central axis of the socket 20a (that is, the central axis of the CFB 16 in the pipe 19 inserted into the socket 20a). A rod lens 23, a condensing lens 28, a half mirror 29, a rotary shutter 32, and a lamp 33 are arranged.

  The lamp 33 is supplied with a power supply current from a lamp power source 38 to emit white light (not shown), and a lens or reflector (not shown) for converting white light emitted from the light bulb as divergent light into parallel light. ). Therefore, the lamp 33 emits white light toward the half mirror 29 as parallel light along the optical axis of the condenser lens 28.

  The half mirror 29 is disposed with an inclination of 45 degrees with respect to the optical axis of the condenser lens 28. The half mirror 29 transmits white light from the lamp 33 and reflects light from a direction perpendicular to the optical axis of the condensing lens 28 along the optical axis of the condensing lens 28. This is a half mirror that is incident on the optical lens 28.

  The rotary shutter 32 interposed between the lamp 33 and the half mirror 29 is a plate having a front shape shown in FIG. In other words, the rotary shutter 32 has a semicircular disk having a relatively small radius (hereinafter referred to as “small radius part 32a”) and a semicircular disk having a relatively large radius (hereinafter referred to as “large radius part 32b”) coaxially joined. Has the shape.

  The rotary shutter 32 is rotatably held by a first motor 34. In other words, the first motor 34 rotates so as to make one rotation while the image sensor 13 captures one frame. The small radius portion 32a always exists outside the optical path of white light from the lamp 33, but the large radius portion 32b enters the optical path of white light and blocks the white light so as to shield the white light. The position of the rotation axis is determined.

  The condensing lens 28 condenses the parallel light incident from the half mirror 29 side along the optical axis toward the base end surface of the CFB 16 in the pipe 19 inserted into the socket 20a. Since the rod lens 23 has a negative power as a whole, the rod lens 23 functions to extend the focal length of the condenser lens 28.

  The first beam splitter 22 includes a reflecting surface that transmits white light emitted from the lot lens 23 and laser light described later toward the base end face of the CFB 16 and reflects light emitted from the base end face of the CFB 16 by 90 degrees. And corresponds to the first separation optical element.

  On the other hand, a collimator lens 39 and a laser unit 40 are arranged in order on the optical axis of the condenser lens 28 bent 90 degrees by the half mirror 29. The laser unit 40 is an apparatus (corresponding to an excitation light source) that emits laser light of a wavelength arbitrarily selected from three types of wavelengths as divergent light, and the collimator lens 39 emits light from the laser unit 40 as divergent light. It is the lens which makes the laser beam which is done parallel light. The collimator lens 39, the half mirror 29, the condenser lens 28, the rod lens 23, and the first beam splitter 22 correspond to an excitation light optical system.

  FIG. 5 is a diagram showing a detailed configuration of the laser unit 40. As shown in FIG. 5, the laser unit 40 includes first to third semiconductor lasers 401 to 403 fixed on a substrate, a rod lens 404 fixed on the substrate, and semiconductor lasers 401 to 403. The first to third drivers 408 for supplying driving currents to the first to third optical fibers 405 to 407 and the semiconductor lasers 401 to 403 for guiding the laser beams emitted from the light emitting points to the base end of the rod lens 404, respectively. ˜410. The rod lens 404 is installed coaxially with the optical axis of the collimator lens 39 so that the tip surface thereof coincides with the front focal point of the collimator lens 39.

  7 to 9 show the wavelength spectra of the laser beams (excitation light 1 to 3) emitted from the first to third semiconductor lasers 401 to 403, respectively, from the living tissue by the laser light (excitation light 1 to 3). FIG. 5 is a graph showing the wavelength spectrum of the generated fluorescence and the transmission wavelength bands of the excitation light cut filters A to C described later corresponding to the laser beams (excitation light 1 to 3), respectively, and the vertical axis (intensity) ) And horizontal axis (wavelength) scale and origin values are common. Although specific values are not shown in these graphs, generally speaking, the wavelength spectrum of the laser light (excitation light 1) emitted from the first semiconductor laser 401 is in the ultraviolet band (wavelength λ1). Thus, the fluorescence peak emitted by the living tissue is generated in the blue to green band. In addition, the wavelength spectrum of the laser light (excitation light 2) emitted from the second semiconductor laser 402 is in the blue band (wavelength λ2), whereby the fluorescence peak emitted from the living tissue occurs in the green to red band. In addition, the wavelength spectrum of the laser light (excitation light 3) emitted by the third semiconductor laser 403 is in the green band (wavelength λ3), whereby the fluorescence peak emitted by the living tissue is generated in the red to infrared band.

  Returning to FIG. 2, the imaging lens 24, the second beam splitter 25, the rotary filter 26, and the spectroscopic lens 24 are sequentially arranged on the optical path of the light emitted from the base end surface of the CFB 16 and reflected by 90 degrees by the first beam splitter 22. A vessel 30 is arranged. The imaging lens 24 is a positive lens (corresponding to a re-imaging optical system) that forms an image appearing on the base end surface of the CFB 16 on the light receiving surface of the spectrometer 30 (and an imaging surface of an imaging device 35 described later). is there. The second beam splitter 25 is a prism (corresponding to a second separation optical element) having a partial reflection surface that transmits part of the light emitted from the imaging lens 24 toward the spectroscope 30 and reflects the rest by 90 degrees. ).

  The rotary filter 26 is a disc having the structure shown in the front view of FIG. 6, and three types of filters (excitation light cut filter A, excitation light cut) are arranged at equal angular intervals of 120 degrees with respect to the center (rotation axis). A filter B and an excitation light cut filter C) are fitted. The excitation light cut filter A has the same transmission wavelength characteristic as that of the excitation light cut filter 14 incorporated between the second imaging lens 12 and the image sensor 13 in the fluorescence observation endoscope 10. As shown, the light corresponding to the wavelength band (λ1) of the excitation light 1 is blocked, but the fluorescence generated by this excitation light is transmitted. Further, as shown in FIG. 8, the excitation light cut filter B blocks light corresponding to the wavelength band (λ2) of the excitation light 2, but transmits fluorescence generated by the excitation light. Further, as shown in FIG. 9, the excitation light cut filter C blocks light corresponding to the wavelength band (λ3) of the excitation light 3, but transmits fluorescence generated by the excitation light. The rotary filter 26 is rotatably held by the second motor 27 at a position where the excitation light cut filters A to C can be inserted into the optical path of the light emitted from the imaging lens 24. The second motor 27 is a stepping motor or a servo motor, and according to control by a control circuit 42 described later, the rotary filter 26 is configured to selectively insert the excitation light cut filters A to C into the optical path and stop them. Rotate. That is, the rotary filter 26 and the second motor 27 correspond to a mechanism for selectively inserting a plurality of filters into the optical path of the light beam. Further, the whole of the control circuit 42 as the control circuit constitutes one of the filter means.

  The spectroscope 30 is generally used and will not be described in detail. However, the outline of the spectroscope 30 is to measure the intensity of several wavelengths of the light detected by the optical sensor, and the measurement result is electronic information ( (Spectral spectrum signal).

  On the other hand, an excitation light cut filter 31 and an image sensor 35 are arranged in order on the optical path of the light reflected by 90 degrees by the second beam splitter 25. Since this excitation light cut filter 31 has the same transmission wavelength characteristics as the excitation light cut filter C shown in FIG. 9, all the laser beams (excitation light 1 to 3) used in this embodiment are blocked and excited. A part of the fluorescence generated by the light 1, a peak wavelength of the fluorescence generated by the excitation light 2 and a part of a longer wavelength band, and almost all of the fluorescence generated by the excitation light 3 are transmitted. That is, this excitation light cut filter 31 constitutes the other of the filter means.

  The image sensor 35 captures an image (image reproduced on the base end face of the CFB 16) formed by the fluorescence transmitted through the excitation light cut filter 31. The image pickup device 35 is a monochrome image pickup device, but may be a color image pickup device.

  The front panel of the housing of the light source processor device 20 has an electrical socket 21 made up of a number of electrodes each conducting with each terminal constituting the electrical connector 17 when the pipe 19 is inserted into the socket 20a, and an external operation. A plurality of switches (in FIG. 2, a mode changeover switch 23a in normal observation mode / fluorescence observation mode / spectral measurement preparation mode, autofluorescence spectroscopic measurement start switch 23b, wavelength selection button [λ1] of the emitted light of the laser unit 40) An operation panel 23 having a selection button 23c, a λ2 selection button 23d, and a λ3 selection button 23e] is provided. The switches 23a to 23e on the operation panel 23 are connected to the control circuit 42, respectively. As a result, operation signals generated by operations on the switches 23a to 23e on the operation panel (corresponding to the operation means) 23 are input to the control circuit 42, respectively. In addition, since any one of the wavelength selection buttons 23c to 23e is released when the other is input, only one of the wavelength selection buttons 23c to 23e is always input.

  The control circuit 42 is connected to the first motor 34, the second motor 27, the lamp power supply 38, and the first to third drivers 408 to 410, and outputs signals for controlling them. .

  Specifically, the control circuit 42 emits white light from the lamp 33 by activating the lamp power supply 38 in any operation mode. Each time the mode changeover switch 23a is turned on, the operation mode is cyclically switched in the order of the normal observation mode, the fluorescence observation mode, and the spectroscopic measurement preparation mode.

  When the operation mode is switched to the normal observation mode, the control circuit 42 controls the first motor 34 to stop the rotary shutter 32 at a rotation position where the arc of the small diameter portion 32a is close to the optical path of white light. Let As a result, the white light emitted from the lamp 33 passes through the rotary shutter 32 and is always incident on the CFB 16.

  In addition, when the operation mode is switched to the fluorescence observation mode, the control circuit 42 controls the first motor 34 in synchronization with a timing signal (vertical synchronization signal indicating the start timing of each frame) generated therein. Then, the first rotary shutter 32 is rotated. As a result, as shown in FIG. 10, the white light emitted from the lamp 33 is rotated only during a period (a period corresponding to the second field) in which the arc of the small diameter portion 32 a of the rotary shutter 32 is close to the optical path of the white light. The light passes through the shutter 32, passes through the half mirror 29, the condenser lens 28, the rod lens 23, and the first beam splitter 22, and enters the CFB 16. The white light distributed through the CFB 16 and the first imaging lens 11 is reflected by the surface of the test part, and is detected by the second imaging lens 12 on the imaging surface of the imaging device 13 through the excitation light cut filter 14. An image of the portion is formed and converted into a video signal for the second field.

  At the same time, the control circuit 42 controls the first driver 408 so that the first driver 408 is only in a period during which the large-diameter portion 32b of the rotary shutter 32 blocks white light (a period corresponding to the first field). A laser beam (excitation light 1) is emitted from the first semiconductor laser 401 connected to. As a result, as shown in FIG. 10, the excitation light 1 emitted from the laser unit 40 passes through the half mirror 29, the condensing lens 28, the rod lens 23, and the first beam splitter 22, and enters the CFB 16. The test portion irradiated with the excitation light 1 guided through the CFB 16 and the first imaging lens 11 emits fluorescence in the wavelength band shown in FIG. 7, and the fluorescence and the excitation light reflected on the surface of the test portion. The second imaging lens 12 forms an image of the test part based only on this fluorescence on the imaging surface of the imaging element 13 through the excitation light cut filter 14 and is converted into a video signal for the first field.

  Further, the control circuit 42 rotates the first rotary shutter 32 when the operation mode is switched to the spectroscopic measurement preparation mode. At the same time, the control circuit 42 controls the third driver 410 to control the third driver 410 only during a period during which the large-diameter portion 32b of the rotary shutter 32 blocks white light (a period corresponding to the first field). A laser beam (excitation light 3) is emitted from the third semiconductor laser 410 connected to. As a result, as shown in FIG. 10, the excitation light 3 emitted from the laser unit 40 passes through the half mirror 29, the condensing lens 28, the rod lens 23, and the first beam splitter 22, and enters the CFB 16. The test portion irradiated with the excitation light 3 through the CFB 16 and the first imaging lens 11 emits fluorescence in the wavelength band shown in FIG. 9, and the excitation light reflected on the surface of the fluorescence and the test portion is the first. Through the imaging lens 11, each image of the test portion is formed on the tip surface of the CFB 16. This image is transmitted to the base end surface of the CFB 16, and an image based on this fluorescence alone is re-imaged on the imaging surface of the imaging device 35 through the excitation light cut filter 31 by the imaging lens 24, and the image for the first field. Converted to a signal.

  Further, when the spectroscopic measurement start switch 23b is turned on during the spectroscopic measurement preparation mode, the control circuit 42 switches the operation mode to the spectroscopic measurement mode, and the driver corresponding to the wavelength selection buttons 32c to 32e that are turned on at that time. 408 to 410 are controlled, and laser beams are emitted from the semiconductor lasers 401 to 403 connected to the controlled drivers 408 to 410. As a result, as shown in FIG. 10, the laser light emitted from the laser unit 40 passes through the half mirror 29, the condensing lens 28, the rod lens 23 and the first beam splitter 22 and enters the CFB 16. At the same time, the control circuit 42 controls the second motor 27 to insert the excitation light cut filters A to C corresponding to the controlled drivers 408 to 410 into the optical path from the CFB 16 to the spectrometer 30. The test portion irradiated with the laser light through the CFB 16 and the first imaging lens 11 emits fluorescence in a wavelength band corresponding to the wavelength band of the laser light, and this fluorescence passes through the first imaging lens 11 and passes through the CFB 16. An image of the test part is formed on the tip surface. This image is transmitted to the base end surface of the CFB 16, and is re-imaged on the imaging surface of the imaging device 35 through the excitation light cut filter 31 by the imaging lens 24 and the second beam splitter 25, and the image for the first field. The laser unit 40 on the light receiving surface of the spectroscope 30 through the excitation light cut filters A to C in the rotary filter 26 that is converted into a signal and is driven corresponding to the wavelength selection buttons 32 c to e that are input at that time. An image by fluorescence corresponding to the laser light emitted from the laser beam is re-imaged and converted into a spectral signal. Note that when the spectroscopic measurement start switch 23b is turned on again during the spectroscopic measurement mode, the operation mode returns to the spectroscopic measurement preparation mode. Further, when the mode switch 23a is turned on during the spectroscopic measurement mode, the operation mode is switched to the normal observation mode.

  Further, the control circuit 42 is connected to the video signal processing / spectral spectrum signal processing circuit 43. The control circuit 42 also inputs a timing signal to the video signal processing / spectral spectrum signal processing circuit 43 and the current operation mode. , And the type of excitation light corresponding to the excitation light selection switches 23c to 23e currently input on the operation panel 23 or the type of light currently introduced into the CFB 16 is notified.

  The video signal processing and spectral spectrum signal processing circuit 43 is connected to each electrode constituting the electrical socket 21. Therefore, the RGB video signals output from the imaging device 13 in the fluorescence observation endoscope 10 are input to the video signal processing and spectral signal processing circuit 43 through the electrical connector 17 and the electrical socket 21. Similarly, the video signal processing and spectral spectrum signal processing circuit 43 is connected to the imaging device 35 and the spectroscope 30 in the light source processor device 20. Therefore, the video signal output from the imaging device 35 and the spectral signal output from the spectroscope 30 are input to the control circuit 42. Further, a monitor 60 is connected to the video signal processing / spectral spectrum signal processing circuit 43. The video signal processing and spectral spectrum signal processing circuit 43 includes RGB video signals input from the imaging device 13 of the fluorescence observation endoscope 10, video signals output from the imaging device 35 in the light source processor device 20, and a spectroscope. By processing the spectral signal output from 30, a normal color image moving image is displayed in the normal observation mode, and a normal image obtained by the imaging element 13 of the fluorescence observation endoscope 10 in the fluorescence observation mode. A screen showing a moving image of a color image and a moving image of a fluorescent image side by side, a moving image of a normal color image obtained by the imaging element 13 of the fluorescence observation endoscope 10 and an imaging device 35 in the light source processor device 20 in the spectroscopic measurement preparation mode. In the spectroscopic measurement mode, a screen that displays the moving images of fluorescent images obtained by The screen shown side by side graph indicated by the input spectrum signal from the spectroscope 30 in addition to the video movie and fluorescence images of a color image is displayed on the monitor 60 (see FIG. 11).

  FIG. 12 is a block diagram showing the internal structure of the video signal processing / spectral spectrum signal processing circuit 43. As shown in FIG. 12, in the video signal processing and spectral spectrum signal processing circuit 43, R, G, B video signals output from the image sensor 13 and video signals output from the image sensor 35. Is input to the preceding video signal processing circuit 431. This front-stage video signal processing circuit 431 is connected to a memory 432, this memory 432 is connected to a scan converter 433, this scan converter 433 is connected to a rear-stage video signal processing circuit 434, and this rear-stage video signal processing circuit 434 has a monitor 60. Is connected. Further, the information output from the control circuit 42 is input to the preceding video signal processing circuit 431 and the scan converter 433, respectively. Further, the spectral signal output from the spectroscope 30 is input to the AD converter 435. The AD converter 435 is connected to a memory 436, which is connected to a graph generation block 437, and this graph generation block 437 is connected to a scan converter 433. Further, the video signal processing and spectral signal processing circuit 43 is provided with a timing controller 438 for generating a synchronization signal for operating the circuits 431 to 437 in synchronization with the timing signal received from the control circuit 42. Yes.

  The pre-stage video signal processing circuit 431 is a circuit for performing predetermined processing on the RGB video signals sent from the image sensor 13 and the video signals sent from the image sensor 35. Processing performed by the pre-stage video signal processing circuit 431 on each video signal includes high-frequency component removal, amplification, blanking, clamping, white balance, gamma correction, analog-digital conversion, and color separation.

  The inside of the memory 432 is a video signal (R video signal, G video signal) that is input from the image sensor 13 to the preceding video signal processing circuit 431 and subjected to the above processing while white light is introduced into the CFB 16 in each mode. , B video signal) is stored (overwritten) in each of the R video signal region 432a, the G video signal region 432b, the B video signal region 432c, and the imaging element 13 while the excitation light 1 is being introduced into the CFB 16 in the fluorescence observation mode. R video signal region 432d and G fluorescent video signal region 432e in which the video signals (R video signal, G video signal, B video signal) input to the preceding video signal processing circuit 431 and subjected to the above processing are respectively stored. , B fluorescent image signal area 432f. In the case where the image sensor 35 is a color image sensor, a video signal (R video image) that has been input from the image sensor 35 to the preceding video signal processing circuit 431 and subjected to the above processing in the spectroscopic measurement preparation mode and the spectroscopic measurement mode. Signal, G video signal, and B video signal) are stored in the R fluorescent video signal region 432d, the G fluorescent video signal region 432e, and the B fluorescent video signal region 432f, respectively. On the other hand, when the image pickup device 35 is a monochrome image pickup device, the video signal input from the image pickup device 35 to the preceding-stage video signal processing circuit 431 and subjected to the above processing has exactly the same content. They are stored in the fluorescent video signal area 432d, the G fluorescent video signal area 432e, and the B fluorescent video signal area 432f.

  On the other hand, the AD converter 435 is a circuit that converts a spectral signal input as an analog signal into a digital signal. The spectrum signal converted into a digital signal by the AD converter 435 is once written in the memory 436, and converted into image data of a spectrum spectrum graph in which the horizontal axis indicates the wavelength and the vertical axis indicates the intensity by the graph generation block 437. Converted.

  In the normal observation mode, the scan converter 433 receives video signals (R video signal and G video signal from the R video signal area 432a, the G video signal area 432b, and the B video signal area 432c, respectively, for each period corresponding to each frame. , B video signal) and input to the subsequent video signal processing circuit 434.

  Further, in the fluorescence observation mode, the scan converter 433 receives video signals (R video signal, G) from the R video signal region 432a, the G video signal region 432b, and the B video signal region 432c for each period corresponding to each frame. Video signals, B video signals), and video signals are read from the R fluorescent video signal region 432d, the G fluorescent video signal region 432e, and the B fluorescent video signal region 432f, respectively. The scan converter 433 receives the video signal read from the R video signal region 432a, the G video signal region 432b, and the B video signal region 432c, the R fluorescent video signal region 432d, the G fluorescent video signal region 432e, and the B fluorescent video signal region 432f. Are combined with each other to generate a video signal for displaying a normal color image and a fluorescent image (fluorescent image captured through the second imaging lens 12) side by side, and a subsequent video signal processing circuit 434 is generated. To enter.

  Further, in the spectroscopic measurement preparation mode, the scan converter 433 receives video signals (R video signal, R video signal region 432a, G video signal region 432b, and B video signal region 432c for each period corresponding to each frame, respectively. (G video signal, B video signal) and video signals are read from the R fluorescent video signal region 432d, the G fluorescent video signal region 432e, and the B fluorescent video signal region 432f, respectively. The scan converter 433 receives the video signal read from the R video signal region 432a, the G video signal region 432b, and the B video signal region 432c, the R fluorescent video signal region 432d, the G fluorescent video signal region 432e, and the B fluorescent video signal region 432f. Are combined with each other to generate a video signal for displaying a normal color image and a fluorescent image (fluorescent image captured through the first imaging lens 11) side by side, and a subsequent video signal processing circuit 434 is generated. To enter.

  In the spectroscopic measurement mode, the scan converter 433 receives image data indicating a spectroscopic spectrum graph from the graph generation block 437 in addition to the video signal read in the spectroscopic measurement preparation mode. The scan converter 433 receives the video signal read from the R video signal region 432a, the G video signal region 432b, and the B video signal region 432c, the R fluorescent video signal region 432d, the G fluorescent video signal region 432e, and the B fluorescent video signal region 432f. The image signal read from the image data and the image data received from the graph generation block 437 are combined with each other, and the normal color image, the fluorescence image (fluorescence image captured through the first imaging lens 11), and the spectral spectrum graph are displayed side by side. A video signal is generated and input to the subsequent video signal processing circuit 434.

  The post-stage video signal processing circuit 434 performs processing such as digital / analog conversion, encoding, impedance matching, and the like on the video signal input from the scan converter 433 and outputs the result to the monitor 60. As a result, a real-time moving image of the normal color image is displayed on the monitor 60 in the normal observation mode, and a real-time image of the normal color image and the fluorescent image captured through the second imaging lens 12 are displayed in the fluorescence observation mode. The images are displayed side by side. In the spectroscopic measurement preparation mode, the real time image of the normal color image and the real time image of the fluorescent image captured through the first imaging lens 11 are displayed side by side. In the spectroscopic measurement mode, the real time image of the normal color image is displayed. , The real-time image of the fluorescence image captured through the first imaging lens 11 and the spectral spectrum graph are displayed side by side (see FIG. 11).

  An operator using the endoscope system configured as described above first switches the operation mode of the control device 42 by appropriately pressing the mode switch 23a after turning on the main power to the control device 42. Switch to normal observation mode. When the mode is switched to the normal observation mode, white light is always emitted from the distal end (first imaging lens 11) of the body cavity insertion portion 10a of the fluorescence observation endoscope 10 and is passed through the second imaging lens 12 on the monitor 60. The captured normal color image is displayed. Therefore, the operator operates the fluorescence observation endoscope 10 while viewing the normal color image displayed on the monitor 60, and inserts the body cavity insertion portion 10a into the body cavity of the subject. Lead to the department.

  When the test portion is captured in the normal color image, the operator switches the operation mode of the control device 42 to the fluorescence observation mode by turning on the mode changeover switch 23a once. Then, white light and excitation light 1 are alternately emitted from the first imaging lens 11 at the tip of the body cavity insertion portion 10 a for each field, and both images are captured on the monitor 60 through the second imaging lens 12. The normal color image and the fluorescent image are displayed side by side.

  When a dark part that is likely to be an abnormal part is detected in the fluorescent image, the operator switches the operation mode of the control device 42 to the spectroscopic measurement preparation mode by turning on the mode changeover switch 23a once. Then, white light and excitation light 3 are alternately emitted from the first imaging lens 11 at the tip of the body cavity insertion portion 10a for each field, and the fluorescence image displayed on the monitor 60 is Then, the fluorescent image captured through the first imaging lens 11 is switched. Therefore, the surgeon finely adjusts the direction of the distal end of the body cavity insertion portion 10a while looking at the normal color image and the fluorescence image displayed on the monitor 60, and suspects that the suspected part is an abnormal part. At the center of the fluorescent image. In this way, the fact that the suspected part is captured at the center of the fluorescent image means that the suspected part exists on the optical axis of the first imaging lens 11. Therefore, the surgeon moves the tip of the body cavity insertion portion 10a closer to the suspected site while finely adjusting the direction of the tip of the body cavity insertion portion 10a so that the suspected site does not deviate from the center of the fluorescence image. When the distal end of the body cavity insertion portion 10a is brought close to and brought into contact with the suspected site in this way, the surface of the first imaging lens 11 is pressed against the suspected site.

  Therefore, the surgeon switches the operation mode of the control device 42 to the spectroscopic measurement mode by turning on the measurement start button 23b, and presses e from any wavelength selection button 23c, thereby causing laser light of any wavelength ( Excitation light 1-3 is irradiated to a suspected part. Then, the fluorescence generated from the biological tissue at the suspected site due to the laser light is spectroscopically measured by the spectroscope 30, and the spectroscopic spectrum graph as the measurement result is displayed on the monitor 60. The surgeon makes a judgment as to whether or not the suspected site is actually abnormal while looking at the spectral spectrum graph.

  As described above, according to the present embodiment, an image of the test part is picked up by the image sensor 35 through the CFB 16 and the first imaging lens 11 for irradiating the test part with laser light as excitation light. Therefore, the center of the fluorescent image displayed on the monitor 60 by the video signal obtained by this imaging coincides with the center of the first imaging lens 11. Therefore, the first imaging lens 11 that irradiates the laser light can be pressed against the test part by bringing the body cavity insertion part 10a close to the test part while capturing the test part at the center of the fluorescence image. It becomes. Moreover, this fluorescence image is the object of spectroscopic measurement by the spectroscope 40 itself. Therefore, the surgeon can accurately recognize the range of the image that is the object of spectroscopic measurement.

1 is an external view showing an external appearance of an endoscope system according to an embodiment of the present invention. Schematic showing the internal configuration of the endoscope system Side view showing appearance of fluorescence observation endoscope Front view of rotary shutter Detailed view showing the structure of the laser unit Front view of rotary filter A graph showing the wavelength spectrum of the excitation light 1 and the transmission wavelength band of the excitation light cut filter A Graph showing the wavelength spectrum of the excitation light 2 and the transmission wavelength band of the excitation light cut filter B A graph showing the wavelength spectrum of the excitation light 3 and the transmission wavelength band of the excitation light cut filter C Sequence diagram showing the types of light introduced into the light guide in the fluorescence observation mode, the spectroscopic measurement preparation mode, and the spectroscopic measurement mode Figure showing a monitor display example Block diagram showing configuration of video signal processing and spectral spectrum signal processing circuit

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fluorescence observation endoscope 11 1st image formation lens 12 2nd image formation lens 13 Image pick-up element 16 CFB
DESCRIPTION OF SYMBOLS 20 Light source processor apparatus 22 1st beam splitter 24 Imaging lens 25 2nd beam splitter 29 Half mirror 30 Spectroscope 35 Image pick-up element
40 Laser unit 42 Control circuit

Claims (6)

A fluorescence observation endoscope apparatus that irradiates a test part in a body cavity with an excitation light and captures an image of fluorescence emitted from a living tissue of the test part excited by the excitation light with an endoscope,
An endoscope including an imaging optical system at its distal end, and a built-in fiber bundle that transmits an image of the test part formed on the distal end surface by the imaging optical system to the proximal end surface;
An excitation light source that emits the excitation light;
An optical system that guides the excitation light emitted from the excitation light source to the base end face of the fiber bundle, and includes a condensing lens that converges the excitation light to the end face of the fiber bundle; and
A first separation optical element that is disposed between the end face of the fiber bundle and the condensing lens, and separates the light beam emitted from the end face of the fiber bundle from the optical path of the excitation light;
A re-imaging optical system that re-images the image transmitted to the base end face of the fiber bundle by converging the light beam separated by the first separation optical element;
An image sensor for imaging an image re-imaged by the re-imaging optical system;
A second separation optical element that is disposed between the first separation optical element and the imaging element and further separates the light beam separated by the first separation optical element;
A spectroscope for spectroscopically measuring the light beam separated by the second separation optical element;
A fluorescence observation endoscope comprising: filter means disposed between the first separation optical element, the imaging optical element, and the spectrometer, and blocking light in the same wavelength band as the excitation light. Mirror device. The fluorescence observation endoscope apparatus according to claim 1, wherein the first separation optical element is a beam splitter that transmits the excitation light and reflects a light beam emitted from a base end face of the fiber bundle. The excitation light source selectively emits excitation light of a plurality of types of wavelengths,
The filter means includes a plurality of filters that respectively block light having the same wavelength as the excitation light, and the plurality of filters between the second separation optical element and the spectrometer. A mechanism for selectively inserting into the optical path of the light beam separated by the light source, and a mechanism for inserting a filter that blocks light having the same wavelength as the excitation light emitted by the excitation light source into the optical path of the light beam. The fluorescence observation endoscope apparatus according to claim 1, further comprising a control circuit that controls the fluorescence observation endoscope apparatus. The filter means includes a filter that is disposed between the second separation optical element and the imaging element and blocks light having the same wavelength as all types of excitation light emitted from the excitation light source. The fluorescence observation endoscope apparatus according to claim 3. A white light source that emits white light;
An objective optical system provided at the distal end of the endoscope;
A second image pickup device for picking up an image of the test part formed by the objective optical system,
2. The fluorescence observation endoscope apparatus according to claim 1, wherein the excitation light optical system selectively guides the excitation light and white light emitted from the white light source to the fiber bundle. The fluorescence observation endoscope apparatus according to claim 5, further comprising a filter that blocks light having the same wavelength band as the excitation light between the objective optical system and the second imaging element.