JP4731225B2 - Fluorescence observation apparatus and light source apparatus - Google Patents

Description

  The present invention relates to a fluorescence observation apparatus that inserts a probe through a forceps channel of an endoscope, irradiates an examination portion with the excitation light and measures fluorescence, and a light source device used in such a fluorescence observation apparatus About.

  A conventional electronic endoscope system (electronic endoscope system) introduces white illumination light into a body cavity of a subject through a light guide incorporated in a body cavity insertion tube of the endoscope (electronic endoscope). At the same time, the imaging device incorporated at the distal end of the body cavity insertion tube images the body cavity inner wall illuminated by the white illumination light (i.e., forms an image in which the white illumination light reflected on the surface of the body cavity inner wall is connected by the objective optical system). The image in the body cavity is displayed on the TV monitor based on the image signal obtained by the imaging.

  On the other hand, when a biological tissue is irradiated with light of a specific wavelength as excitation light, fluorescence (autofluorescence) having a spectrum longer than the wavelength of the excitation light is emitted from the biological tissue. The intensity of the autofluorescence (Especially, the intensity of the green light region) is lower in a living body from a diseased tissue (tumor, cancer) than from a normal tissue. Using this, excitation light is introduced into the body cavity through the forceps channel of the existing endoscope and the inner wall of the body cavity irradiated with the excitation light is observed with fluorescence (that is, biological tissue excited by the excitation light) In addition, a fluorescence observation system in which an image formed by an image sensor that captures an image formed by fluorescence generated by the objective optical system and an image [visible image] based on an image signal obtained by the imaging is displayed on a monitor has been put into practical use.

  Furthermore, in recent years, it has been proposed to integrate an endoscope system and a fluorescence observation system in various modes for the purpose of performing more advanced image processing by a simpler operation.

  Among them, the one described in Patent Document 1 selectively introduces white illumination light and excitation light from a light source device to a light guide of an endoscope (fiber scope), and introduces an objective optical system and an image. The image inside the body cavity transmitted through the guide is directly imaged when white illumination light is introduced, and is imaged through an excitation light cut filter when excitation light is introduced. According to this, the image at the time of introducing the white illumination light (normal observation image) and the image at the time of introduction of the excitation light (fluorescence observation image) can be displayed on the monitor selectively or side by side.

  However, from a fluorescence observation image, it is possible to know a site (dark part) that is likely to be a lesion, but it is possible to accurately determine whether it is a malignant site that requires immediate treatment or a benign site that does not require treatment. Since it cannot be determined, further detailed examination (biopsy after collecting biological tissue) is required.

Therefore, through the light probe inserted in the forceps channel of the endoscope, the excitation light emitted from the excitation light source is irradiated to the inner wall of the body cavity and the fluorescence from the living tissue irradiated with the excitation light is guided and guided. There has also been proposed a system in which the ratio of the amounts of two specific wavelength components in the emitted fluorescence is calculated, and the ratio can be displayed as a determination element for determining whether or not it is a malignant site (Patent Document 2). To 4). This utilizes a phenomenon in which the wavelength characteristic of fluorescence generated due to excitation light having a specific wavelength changes depending on the state of a living tissue.
JP-A-10-295632 JP 2003-174999 A JP 2003-180616 A JP 2003-199746 A

  However, in these systems, since the fluorescence observation image as described above could not be acquired, it was necessary to determine which portion to measure with the light probe on the visible image. It may be considered that the configuration described in Patent Document 1 is combined with the apparatus described in Patent Documents 2 to 4, but the wavelength of the excitation light introduced into the light guide for light observation and the light probe. If the wavelength of the excitation light to be introduced into is different, the spectral characteristics of the generated fluorescence will also be different, so that both of these excitation lights cannot be introduced simultaneously. Therefore, since one of the light sources for the excitation light is always stopped, it is inevitable that the configuration is wasteful when viewed as a whole.

  Therefore, the present invention selectively introduces the excitation light emitted from one excitation light source into the light guide of the endoscope for fluorescence observation or introduces it into the light probe for spectroscopic measurement. It is an object of the present invention to provide a fluorescence observation device that can be used and a light source device used in such a fluorescence observation device.

  The first aspect of the fluorescence observation apparatus according to the present invention, which has been devised to solve the above-described problems, is not limited to the display method of the acquired video signal and spectroscopic measurement result. Specifically, a fluorescence observation apparatus that introduces excitation light into a body cavity and spectroscopically measures fluorescence emitted from a living tissue of a subject excited by the excitation light, and includes an objective optical system and an illumination window at the tip thereof. An endoscope having a hollow channel passing through its proximal end and distal end and a light guide for guiding light from the proximal end to the illumination window, and an insertion part in a body cavity; and the objective optical system. An imaging device that sequentially captures an image of the detected portion, converts it into a video signal, and outputs it; a light probe that is inserted through the channel and that emits light introduced from its proximal end; and a visible illumination A visible light source that emits light, an illumination optical system that guides the optical path of visible illumination light emitted from the visible light source to the proximal end of the light guide, and excitation that emits excitation light in a wavelength band that excites living tissue to emit fluorescence With light source An optical path switching optical element that selectively switches the optical path of the excitation light to any one of an optical path leading to a base end of the light probe and an optical path intersecting the optical path of the visible illumination light, the optical path of the visible illumination light, and the optical path An optical path combining optical element that combines both optical paths at the intersection with the optical path of the excitation light switched by the optical path switching optical element, and excitation light that blocks only the excitation light on the optical path from the objective optical system to the imaging device A cut filter; and a spectroscopic measurement unit that spectroscopically measures the fluorescence while the optical path switching optical element switches the optical path of the excitation light to an optical path that reaches the proximal end of the light probe. To do.

  The second aspect of the fluorescence observation apparatus according to the present invention includes a configuration for displaying the acquired video signal and the spectroscopic measurement result. Specifically, a fluorescence observation apparatus that introduces excitation light into a body cavity and spectroscopically measures fluorescence emitted from a living tissue of a subject excited by the excitation light, and includes an objective optical system and an illumination window at the tip thereof. An endoscope having a hollow channel passing through its proximal end and distal end and a light guide for guiding light from the proximal end to the illumination window, and an insertion part in a body cavity; and the objective optical system. An imaging device that sequentially captures an image of the detected portion, converts it into a video signal, and outputs it; a light probe that is inserted through the channel and that emits light introduced from its proximal end; and a visible illumination A visible light source that emits light, an illumination optical system that guides the optical path of visible illumination light emitted from the visible light source to the proximal end of the light guide, and excitation that emits excitation light in a wavelength band that excites living tissue to emit fluorescence With light source An optical path switching optical element that selectively switches the optical path of the excitation light to any one of an optical path leading to a base end of the light probe and an optical path intersecting the optical path of the visible illumination light, the optical path of the visible illumination light, and the optical path An optical path combining optical element that combines both optical paths at the intersection with the optical path of the excitation light switched by the optical path switching optical element, and excitation light that blocks only the excitation light on the optical path from the objective optical system to the imaging device While the cut filter and the optical path switching optical element are switching the optical path of the excitation light to the optical path leading to the proximal end of the light probe, an operation is performed by an operator and a spectroscopic measurement means for spectroscopically measuring the fluorescence. An operation member and only the visible illumination light is introduced into the light guide according to an operation on the operation member and the light guide of the excitation light And a first state in which the introduction to the light probe is stopped, and the optical path switching element switches the optical path of the excitation light to an optical path intersecting the optical path of the visible illumination light, and then only the excitation light is transmitted to the light guide. The second state to be introduced into the light guide, the optical path switching element switching the optical path of the excitation light to the optical path reaching the proximal end of the light probe, and then introducing the excitation light into the proximal end of the light guide and the visible illumination A control unit that selectively switches between a third state in which the introduction of light into the light guide is stopped, a developing unit that develops a spectral measurement result by the spectroscopic measuring unit into a graph image, and an image by the video signal And a converter for generating a video signal for displaying the images developed by the developing means side by side, and a monitor for displaying a screen based on the video signal , Provided.

  In addition, the light source device according to the present invention includes an objective optical system and an illumination window at the distal end thereof, and includes a hollow channel that passes through the proximal end and the distal end, and a light guide that guides light from the proximal end to the illumination window. An imaging device that sequentially captures an image of the test portion formed by the inserted body cavity portion and the objective optical system, converts the image into a video signal, and outputs the video signal on the optical path from the objective optical system to the imaging device The proximal end of the light guide in an endoscope having an excitation light cut filter that blocks only the excitation light in FIG. 5 is connected, and is inserted through the channel and emits light introduced from the proximal end from the distal end. A light source device to which a proximal end of a light probe is connected, and a visible light source that emits visible illumination light, and an optical path of the visible illumination light emitted from the visible light source is guided to the proximal end of the light guide A bright optical system; an excitation light source that emits excitation light in a wavelength band that excites biological tissue to emit fluorescence; and an optical path to the proximal end of the light probe, and the visible illumination, selectively in the optical path of the excitation light An optical path switching optical element that switches to one of the optical paths that intersect the optical path of the light, and an optical path synthesis that combines both optical paths at the intersection of the optical path of the visible illumination light and the optical path of the excitation light switched by the optical path switching optical element And an optical element.

  According to the fluorescence observation device and the light source device of the present invention configured as described above, the optical path of the excitation light emitted from the excitation light source is selectively passed to the optical path synthesis optical element by the optical path switching optical element, and Switching to any of the optical paths leading to the proximal end of the light probe. When the optical path is switched to the former, the excitation light is combined with the optical path of the visible illumination light from the visible light source by the optical path synthesis optical element, and introduced into the light guide of the endoscope through the illumination optical system. And it is guided by this light guide and irradiated to a test part from an illumination window. When fluorescence is emitted from the living tissue of the test part excited by the excitation light irradiated in this way, an image of this fluorescence is formed by the objective optical system of the endoscope, and the excitation light component is removed by the excitation light cut filter. In this state, this image is converted into an image signal by the image sensor. Based on this image signal, a fluorescence image of the test part can be displayed. On the other hand, when the optical path is switched to the latter, the excitation light is introduced into the light probe. Then, the light is guided by the light probe and irradiated from the tip to the test portion. The fluorescence emitted from the living tissue of the test part excited by the irradiated excitation light is used for spectroscopic measurement. As described above, according to the present invention, the excitation light introduced into the light guide of the endoscope for fluorescence observation and the excitation light introduced into the light probe for spectroscopic measurement are emitted from a common excitation light source. Therefore, the required number of excitation light sources can be reduced and the cost can be reduced.

  According to the fluorescence observation apparatus of the present invention, excitation light emitted from one excitation light source is selectively introduced into a light guide of an endoscope for fluorescence observation, or a light probe for spectroscopic measurement. Can be introduced.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of an endoscope system which is an embodiment of a fluorescence observation apparatus according to the present invention. As shown in FIG. 1, the endoscope system includes an endoscope 10, a light probe P, a light source device 20, and a monitor 60.
<Endoscope>
FIG. 2 is a side view showing the appearance of the endoscope. The endoscope 10 is an improvement of a normal electronic endoscope for fluorescence observation. As shown in FIG. 2, the endoscope 10 is inserted into a body cavity and is elongated to be inserted into the body cavity. 10a, an angle knob 10c for bending the distal end portion of the body cavity insertion portion 10a, an operation portion 10b as an operation member provided with two switches 17a and 17b, the operation portion 10b, and the light source processor device 20 A light guide flexible tube 10e for connection and a connector 10d provided at the base end of the light guide flexible tube 10e are provided.

  As shown in FIG. 1, an illumination window and a photographing window into which a light distribution lens 11 and an objective lens 12 are fitted are formed on the distal end surface of the body cavity insertion portion 10a. In the body cavity insertion portion 10 a, an imaging element (color CCD, corresponding to an imaging device) 13 that captures an image of a subject formed by the objective lens (objective optical system) 12, and the imaging element 13 An amplifier 14 for amplifying the output image signal is incorporated. An excitation light cut filter 15 is provided between the objective lens 12 and the image sensor 13 for removing the excitation light component from the light transmitted through the objective lens 12.

  The signal cable 18 for transmitting the image signal amplified by the amplifier 14 is passed through the body cavity insertion portion 10a, the operation portion 10b, and the light guide flexible tube 10e, and is provided on the end face of the connector 10d. It is electrically connected to any terminal (not shown) constituting the connector 10h. In parallel with the signal cable 18, the light guide fiber bundle 16 is drawn through the body cavity insertion portion 10a, the operation portion 10b, and the light guide flexible tube 10e. The distal end of the light guide fiber bundle 16 faces the light distribution lens 11 in the distal end portion of the body cavity insertion portion 10a, and the proximal end thereof is inserted and fixed in the metal pipe 10i protruding from the end face of the connector 10d. Has been. The signal cables 19a and 19b for transmitting signals corresponding to the operations of the switches 17a and 17b as operation members are led through the operation portion 10b and the light guide flexible tube 10e, and are connected to the end surface of the connector 10d. It is electrically connected to any terminal (not shown) constituting the provided electrical connector 10h.

A hollow forceps channel 10f that opens to the distal end surface of the body cavity insertion portion 10a is built in, and the proximal end of the forceps channel 10f is connected to a forceps port 10g that protrudes from the side surface of the operation portion 10b. Communicate. Therefore, forceps (such as a light probe P described later) are inserted into the forceps channel 10f from the forceps port 10g from the outside of the operation portion 10b, and the tip of the forceps protrudes from the tip surface of the body cavity insertion portion 10a. it can.
<Light probe>
FIG. 3 is a diagram showing a schematic configuration of the light probe P from the side, and FIG. 4 is a diagram showing the tip surface thereof. As shown in these drawings, the light probe P includes a first optical fiber bundle F1 (corresponding to a first optical fiber) that guides excitation light for exciting a living tissue to generate autofluorescence, and a living body. It is composed of four second optical fiber bundles F2 (corresponding to second optical fibers) for guiding fluorescence emitted from the tissue. Each of the optical fiber bundles F1 and F2 has a configuration in which four second optical fiber bundles F2 are arranged around the first optical fiber bundle F1 and covered with a covering tube as a whole in a region that is a majority from the tip. Are bundled together. Further, at the base end portion, the first optical fiber bundle F1 and the four second optical fiber bundles F2 are separated, and the first optical fiber bundle F1 is directly covered with the covering tube, and the four light beams The fiber bundles F2 are bundled together and covered with a coating tube. Hereinafter, the branch made of the first optical fiber bundle F1 is referred to as “first branch part P1”, and the branch made of the four second optical fiber bundles F2 is called “second branch part P2”.

The probe P is inserted into the forceps channel 10f of the endoscope 10 and the proximal ends of the branch portions P1 and P2 are inserted into sockets 20b and 20c provided on the front surface of the light source device 20, respectively. Used in state.
<Light source device>
The light source device 20 selectively introduces white light and excitation light into the end face of the light guide fiber bundle 16 of the endoscope 10 and receives an image signal (image signal of a visible image) received through the electrical connector 10 h of the endoscope 10. Alternatively, the main function is to generate a video signal by performing image processing on the image signal of the fluorescence observation image) and output the video signal to the monitor 60. Excitation light is applied to the base end face of the first branch portion P1 of the light probe P. In addition to being introduced, this is a device with a function to spectroscopically measure the fluorescence emitted from the base end face of the second branch part P2.

  The front panel of the casing of the light source device 20 is provided with a socket 20a which is a cylinder into which the pipe 10i of the endoscope 10 is inserted from the outer surface side. The through hole formed in the socket 20a communicates with the internal space of the light source device 20. In the inner space of the light source device 20, a condenser lens is sequentially arranged along an extension line of the central axis of the socket 20a (that is, the central axis of the light guide fiber bundle 16 in the pipe 10i inserted into the socket 20a). 21, a beam splitter 29, a rotary shutter 22, a dimming diaphragm 23, and a lamp 24 are arranged.

  The condensing lens 21 is a lens that condenses the parallel light incident along the optical axis from the lamp 24 side onto the base end face of the light guide fiber bundle 16 in the pipe 10i inserted into the socket 20a (illumination optics). Equivalent to the system).

  The lamp 24 is supplied with a power supply current from the lamp power supply 48 to emit a white light (visible light) including ultraviolet light (not shown), and the white light emitted from the light bulb is converted into parallel light. Lens or reflector (not shown). As a result, the lamp 24 emits white light toward the condenser lens 21 as parallel light along the optical axis of the condenser lens 21 (corresponding to a visible light source).

  The dimming diaphragm 23 is pivotally supported by a second motor 27 to which a drive current is supplied from a second motor drive control circuit 49, and is driven to rotate around the axis by the second motor 27, whereby the lamp 24 It is possible to stop at an arbitrary position between the position where the white light path between the lens and the condenser lens 21 completely exits and the position where the light enters the optical path and completely blocks light.

  As shown in the front view of FIG. 5, the rotary shutter 22 is a disc in which a fan-shaped slit 22 a having a width wider than the cross section of the optical path of white light incident on the condenser lens 21 and a central angle of 180 degrees is formed. Yes, it is rotated by the first motor 28 that is driven and controlled by being supplied with a drive current from the first motor drive control circuit 47. The first motor 28 is installed on a table 26 slidable in a direction perpendicular to the optical path of white light. The table 26 is driven and controlled by being supplied with a drive current from a fourth motor drive control circuit 46. The fourth motor 25 operates. As a result, in the first motor 28, the slit 22a is intermittently inserted into the white light optical path as the rotary shutter 22 is completely removed from the position where the entire rotary shutter 22 is completely excluded from the white light optical path. It is moved between positions (intermittently cut off visible light irradiation).

  In the inner space of the light source device 20, the light is collected in order along the extension line of the central axis of the socket 20 b (that is, the central axis of the first branch portion P1 of the light probe P inserted into the socket 20 b). A lens 31, a mirror 58, and an excitation light source 32 are arranged.

  The condensing lens 31 is a lens that condenses the excitation light emitted from the excitation light source 32 on the base end surface of the first branching portion P1 inserted into the socket 20b.

  The excitation light source 32 is supplied with a drive current from the excitation light drive control circuit 50, thereby converting light of a specific wavelength (ultraviolet light to blue light) used as excitation light into parallel light coaxial with the condenser lens 31. As a light source (laser diode).

  The beam splitter 29 and the mirror 58 described above are provided in the white light path and the excitation light path between the rotary shutter 22 and the condenser lens 21 and between the excitation light source 32 and the condenser lens 31, respectively. On the other hand, it is fixed on a table 56 slidable in parallel with an axis orthogonal to each other. That is, in a state where the table 56 is moved to the most arrow b side, the mirror 58 causes the optical path to reflect the excitation light in the “axis (movement direction of the table 56)” direction in the optical path of the excitation light. It is fixed in a state inclined by 45 degrees with respect to the angle. Similarly, in a state where the table 56 is moved to the most arrow b side, the beam splitter 29 is configured to reflect the excitation light reflected by the mirror 58 in the optical path of white light toward the condenser lens 21. It is fixed in a state inclined by 45 degrees with respect to the optical path. The mirror 58 is a mirror that regularly reflects the excitation light. The beam splitter 29 is a half mirror or a dichroic mirror that transmits white light and reflects excitation light. The table 56 is operated by the fourth motor 25 that is driven and controlled by being supplied with a drive current from the third motor drive control circuit 46. When the table 56 moves from the position shown in FIG. 1 in the direction of the arrow a, the mirror 58 and the beam splitter 29 move to positions where they exit from the optical paths of the excitation light and the white light, respectively. The table 56 is operated by a third motor 57 that is driven and controlled by being supplied with a drive current from a third motor drive control circuit 59. Therefore, the above-described mirror 58 functions as an optical path switching optical element, and the beam splitter 29 functions as an optical path combining optical element.

  In the inner space of the light source device 20, collimator lenses are sequentially arranged along an extension line of the central axis of the socket 20 c (that is, the central axis of the second branch portion P <b> 2 of the light probe P inserted into the socket 20 c). 33, an excitation light cut filter 34 and a spectroscope 35 are arranged.

  The collimator lens 33 is a positive lens that collimates light (fluorescence and excitation light) emitted as diverging light from the base end face of the second branching portion P2 inserted into the socket 20c. The excitation light cut filter 34 is an optical bandpass filter that blocks only the excitation light component from the light transmitted through the collimator lens 33 and transmits only the fluorescence component.

  The spectroscope 35 measures the intensity of each wavelength component contained in the light detected by the line sensor installed on the light receiving surface (hereinafter referred to as “spectrometric measurement”), and the spectral measurement result indicates the light intensity with respect to the wavelength. This is a device that outputs a one-dimensional signal (hereinafter referred to as “measurement wavelength characteristic signal”) indicating the characteristic (wavelength characteristic) (corresponding to the spectroscopic measurement means). That is, since the line sensor is covered with a filter set so that the transmission wavelength is increased by a fixed value for each pixel from one end to the other end, the output of the line sensor is as described above. This is a measured wavelength characteristic signal. The measurement wavelength characteristic signal output from the spectroscope 35 is amplified by an amplifier 36, a noise component is removed by a filter 37, and then converted into a digital signal (AD conversion) by an AD (Analog Digital) converter 38. .

  On the other hand, the front panel of the housing of the light source device 20 has an electrical socket (not shown) made up of a number of electrodes each conducting with each terminal constituting the electrical connector 10h when the pipe 10i is inserted into the socket 20a. An operation panel including a plurality of switches (F panel switch 39) operated from the outside is provided. A foot switch 60 is connected to an input port (not shown) provided on the illumination side panel.

  And the operation signal with respect to each switch 17a, 17b provided in the operation part 10b of the endoscope 10 is each terminal which comprises each signal cable 19a, 19b, the electrical connector 10h, and each electrode which comprises the electrical socket which is not shown in figure. Are input to the system controller 40 mounted inside the light source device 20. Similarly, since each F panel switch 39 and foot switch 60 are also connected to the system controller 40, operation signals generated by operations on each F panel switch 39 and foot switch 60 are also input to the system controller 40, respectively. .

  The system controller 40 is connected to a timing controller 41, a second motor drive control circuit 49, a third motor drive control circuit 59, and a fourth motor drive control circuit 46. The timing controller 41 includes a first motor drive control circuit 47, an excitation light source drive control circuit 50, a spectroscope 35, an AD converter 38, a line memory 51, a third memory 55, a pre-stage signal processing circuit 42, a first The memory 43, the second memory 52, the scan converter 44, and the post-stage signal processing circuit 45 are connected. The image signal output from the amplifier 14 of the endoscope 10 described above is input to the signal processing circuit 42 through the signal cable 18, the terminals constituting the electrical connector 10 h and the electrodes constituting the electrical socket (not shown). Is input. The output terminal of the pre-stage signal processing circuit 42 is connected to each input terminal of the first memory 43 and the second memory 52. The output ends of these memories 43 and 52 are connected to one input end of the scan converter 44. The output terminal of the scan converter 44 is connected to the post-stage signal processing circuit 45. The output terminal of the subsequent signal processing circuit 45 is connected to the input terminal of the monitor 60. On the other hand, the output end of the AD converter 38 is connected to the input end of the line memory 51. The output end of the line memory 51 is connected to the input end of the third memory 55. The output end of the third memory 55 is connected to the other input end of the scan converter 44.

  Among these, the pre-stage signal processing circuit 42 is a circuit for performing predetermined processing on the image signal sent from the image sensor 13 (an image signal in which each frame is composed of two fields in accordance with the interlace method). It is. The processing performed by the pre-stage signal processing circuit 42 on the image signal includes high-frequency component removal, amplification, blanking, clamping, white balance, gamma correction, color separation, and analog-digital conversion.

  The first memory 43 and the second memory 52 are frame images of image signals that are alternately selected in order of frames in accordance with a timing signal (write enable signal) from a timing controller 41, which will be described later, and processed by the preceding signal processing circuit 42 This is an image memory to be stored every time. As shown in FIG. 7A, each of the first and second memories 43 and 52 has a first field image signal and a second field image signal in each frame in separate areas in the logical memory area. Remember.

  The line memory 51 stores the measurement wavelength characteristic signal converted into the digital signal by the AD converter 38 described above, and stores the measurement according to another timing signal (read enable signal) from the timing controller 41 described later. A wavelength characteristic signal is output (see FIG. 8).

  The third memory 55 stores the measured wavelength characteristic signal read from the line memory 51 as a logically two-dimensional image (X axis: wavelength, Y axis: intensity).

  The scan converter 44 reads an image signal from the first memory 43 or the second memory 52 for each frame in accordance with a timing signal from the timing controller 41 to be described later, and further measures the measured wavelength characteristics from the third memory 55 at the time of spectroscopic measurement. This is a circuit that reads a signal and generates a video signal for one screen.

  The post-stage signal processing circuit 45 subjects the video signal generated by the scan converter 44 to digital / analog conversion, encoding, impedance matching, and the like, and outputs the result to the monitor 60.

  The system controller 40 constitutes a control unit together with the timing controller 41, and in the light source device 20 according to the operation signals input from the switches 17 a and 17 b, the F panel switches 39 and the foot switch 60 of the endoscope 10. Each circuit (timing controller 41, third motor drive control circuit 59, fourth motor drive control circuit 46, and second motor drive control circuit 49) is controlled. Specifically, after the main power is turned on, the system controller 40 responds to an instruction of a light amount set by any F panel switch 39 (or a light amount automatically set by an automatic light control circuit (not shown)). By controlling the second motor drive control circuit 49, the amount of white light passing through the dimming diaphragm 23 is adjusted. Further, every time the switch 17a of the endoscope 10 is pressed, the system controller 40 switches its operation mode in the order of the normal white light image observation mode, the fluorescence image observation mode, and the white / fluorescence image observation mode. To the timing controller 41. Similarly, the system controller 40 notifies the timing controller 41 to that effect while the switch 17b of the endoscope 10 is being pressed.

  Then, when the operation mode is switched to the normal white light image observation mode, the system controller 40 controls the third motor drive control circuit 59 in the direction of the arrow a unless the switch 17b is pressed. While moving, the fourth motor drive control circuit 46 is controlled to retract the rotary shutter 22 out of the white light path. Thereby, white light is always introduced into the light guide fiber bundle 16 of the endoscope 10, and an image (usually white light image) of reflected light of visible illumination light on the surface of the test part is obtained from the image sensor 13. Image signals respectively represented by the first field and the second field of each frame are input to the pre-stage signal processing circuit 42. On the other hand, during this period, the excitation light source 32 is stopped (corresponding to the first state).

  Further, when the operation mode is switched to the fluorescence image observation mode, the system controller 40 controls the third motor drive control circuit 59 to move the table 56 in the direction of the arrow b and the fourth motor drive control circuit 46. By controlling the above, the rotary shutter 22 is moved to a position where the slit 22a is intermittently inserted into the optical path of white light as the rotary shutter 22 rotates. Further, by controlling the first motor drive control circuit 47 through the timing controller 41, the rotary shutter 22 is stopped at the rotational position where the white light is blocked, and the excitation light source drive control circuit 50 is controlled, thereby The excitation light is always emitted from the light source 32. Thereby, the excitation light sequentially reflected by the mirror 58 and the beam splitter 29 is always introduced into the light guide fiber bundle 16 of the endoscope 10, and the test part excited by the excitation light is picked up from the imaging device 13. Image signals representing fluorescence images (fluorescence images) emitted from the living tissue by the first field and the second field of each frame are input to the pre-stage signal processing circuit 42 (corresponding to the second state).

  Further, when the operation mode is switched to the white / fluorescence image observation mode, the system controller 40 controls the first motor drive control circuit 47 through the timing controller 41, so that the slit 22a is white light in the period corresponding to the first field. When the rotary shutter 22 is rotated at a phase that passes through the optical path, and the excitation light source drive control circuit 50 is controlled, the excitation light is emitted from the excitation light source 32 only during the period corresponding to the second field. 6A, white light transmitted through the beam splitter 29 is introduced into the light guide fiber bundle 16 of the endoscope 10 during the period corresponding to the first field (corresponding to the first state). ), Excitation light sequentially reflected by the mirror 58 and the beam splitter 29 is introduced during the period corresponding to the second field (corresponding to the second state). As a result, as shown in FIG. 6B, the image sensor 13 captures a normal white light image during the period corresponding to the first field and captures a fluorescence image during the period corresponding to the second field. Then, as shown in FIG. 6C, the image signal based on the normal white light image and the image signal based on the fluorescence image are transferred to the pre-stage signal processing circuit 42 with a time lag for one field.

  Further, when the operation mode is the normal white light observation mode, the system controller 40 controls the fourth motor drive control circuit 46 while the switch 17b of the endoscope 10 is being pressed, thereby rotating the rotary shutter 22. Is moved to a position where the slit 22a is intermittently inserted into the optical path of the white light in accordance with the rotation. Further, by controlling the first motor drive control circuit 47 through the timing controller 41, the rotary shutter 22 is rotated at a phase in which the slit 22a passes through the optical path of the white light during the period corresponding to the first field, and for excitation. By controlling the light source drive control circuit 50, the excitation light is emitted from the excitation light source 32 only during the period corresponding to the second field. Thereby, in the period corresponding to the first field, white light transmitted through the beam splitter 29 is introduced into the light guide fiber bundle 16 of the endoscope 10, while emission of excitation light from the excitation light source 32 is stopped. (Corresponding to the first state). On the other hand, during the period corresponding to the second field, the excitation light passing through the side of the mirror 58 is introduced into the first branching portion P1 of the light probe P, while the white light is blocked by the rotary shutter 22 (third). Equivalent to the state). As a result, in the period corresponding to the first field, an image signal representing a normal white light image is input from the image sensor 13 to the preceding signal processing circuit 42, and in the period corresponding to the second field, the tip of the light probe P Fluorescence emitted by exciting the living tissue of the portion pressed against by the excitation light is received by the spectroscope 35 (in the pre-stage signal processing circuit 42, an image of the excitation light reflected from the subject surface is displayed. An image signal obtained by imaging by the image sensor 13 is input).

  The timing controller 41 generates a timing signal (vertical synchronization signal indicating the start timing of each frame) inside the timing controller 41, and this timing is determined depending on the operation mode instructed from the system controller 40 and the switch 17b is pressed. The signal is appropriately divided and then supplied to each circuit 35, 38, 42 to 45, 47, 50 to 52, 55. Thus, in addition to controlling the first motor drive control circuit 47 and the excitation light source drive control circuit 50 as described above, the other circuits are controlled as follows.

  That is, the timing controller 41 stops the operation of the spectroscope 35 and the AD converter 38 while the operation mode is the normal white light image observation mode and the switch 17b is not pressed, and the line memory 51 Then, reading and reading of data from the third memory 55 are stopped, and the pre-stage signal processing circuit 42 is operated for each field. Then, as shown in FIG. 7A, the first memory 43 and the second memory 52 are alternately selected as the write target memory in the frame order, and the image of the first field of each frame is selected in the selected memories 43 and 52. The signal and the image signal of the second field are stored, and the image signal of the first field and the image of the second field are stored in the scan converter 44 from the memory 43, 52 which is not the write target memory for each frame. The signal is read to generate a video signal for one screen as shown in FIG. 7B, and the post-stage signal processing circuit 45 processes the video signal from the scan converter 44 and outputs it to the monitor 60. . As a result, two moving images of the normal white light image of the test part are displayed side by side on the monitor 60.

  Further, the timing controller 41, while the operation mode is the white / fluorescence image observation mode, is similar to each circuit 35, as long as the operation mode is the normal white light image observation mode and the switch 17b is not pressed. 38, 51, 55, 42, 43, 52, 44, 45 are controlled. As a result, the moving image of the normal white light image of the test part is displayed on the right and the moving image of the fluorescent image is displayed on the left on the monitor 60, respectively.

  Further, the timing controller 41, while the operation mode is the fluorescence image observation mode, is similar to the circuit 35, 38, the circuit 35, 38, as long as the operation mode is the normal white light image observation mode and the switch 17b is not pressed. 51, 55, 42, 43, 52, 44, 45 are controlled. As a result, two moving images of the fluorescence image of the test part are displayed side by side on the monitor 60.

In addition, as shown in FIG. 6D, the timing controller 41 is a period corresponding to the second field of each frame (D) while the operation mode is the normal white light observation mode and the switch 17b is pressed. Every time, the image sensor 13 is shifted by one field), the spectroscope 35 is caused to perform fluorescence spectroscopic measurement, and the measurement wavelength characteristic signal is output, and the AD converter 38 is measured. Is converted to AD, the measured wavelength characteristic signal is stored in the line memory 51, and the stored measured wavelength characteristic signal is developed in the third memory 55 (corresponding to a developing means). At the same time, the timing controller 41 causes the pre-stage signal processing circuit 42 to process only the image signal corresponding to the first field of each frame input from the image sensor 13, and sequentially executes the first memory 43 and the second memory 52 in the frame order. Are alternately selected as memory to be written, and the processed image signal of the first field is stored in the selected memory.

  The timing controller 41 then sends image signals (image signals corresponding to only the first field) from the memories 43 and 52 that are not the write target memory and the third memory 55 to the scan converter 44 for each frame. Then, the measurement wavelength characteristic signal (measurement wavelength characteristic signal corresponding to one graph) is read, and a video signal for one screen is generated. Then, the timing controller 41 causes the post-stage signal processing circuit 45 to process the video signal from the scan converter 44 and output it to the monitor 60. As a result, on the monitor 60, as shown in FIG. 9, a graph (left side of the figure) based on the moving image of the normal white light image (right side of the figure) and the latest acquired measurement wavelength characteristic signal, as shown in FIG. Are displayed side by side.

  The surgeon who uses the fluorescence endoscope system of the present embodiment configured as described above first presses both switches 17a as appropriate to switch the operation mode of the light source device 20 to the normal white light mode. The endoscope 10 is operated to insert the body cavity insertion portion 10a into the body cavity. Then, the operation mode of the light source device 20 is switched to the white / fluorescence image observation mode or the fluorescence image observation mode, the inside of the body cavity is observed as a fluorescence image, and a dark part having a high probability of being a malignant part is searched.

  When a dark part that appears to be a malignant site is found in this fluorescent image, the operator inserts the light probe P through the forceps port 10g with the distal end surface of the body cavity insertion part 10a facing the dark part (test part) Press the tip surface against the area to be examined. Then, the switch 17a is appropriately pressed to return to the normal white light mode, and then the switch 17b is pressed. Then, in a period corresponding to the second field of each frame, excitation light is irradiated from the tip of the light probe P instead of white light, and fluorescence generated from the living tissue of the test part by the excitation light is emitted. The spectroscopic measurement is performed by the spectroscope 35, and the measurement wavelength characteristic signal as a result is stored in the line memory 51, and the image of the corresponding graph is developed in the third memory 55. Then, the graph is displayed on the monitor 60 along with the normal white light image based on the image signal corresponding to the first field of each frame. Based on the spectroscopic measurement result indicated by the graph, the surgeon can confirm whether or not the test part is truly a malignant site.

  Thus, according to the present embodiment, the excitation light introduced into the light guide fiber bundle 16 of the endoscope 10 for fluorescence image capturing for searching for a highly probable portion that is a malignant portion, and the spectrum for the portion. The excitation light introduced into the first branching portion P 1 of the probe P for measurement is emitted from the same excitation light source 32 and switched by the movement of the mirror 58 and the beam splitter 29. Therefore, since only one excitation light source 32 using an expensive high-intensity semiconductor laser is required, it is possible to contribute to the cost reduction of the entire light source device 20.

Schematic which shows the internal structure of the endoscope system by embodiment of this invention. Side view showing the appearance of the endoscope Side view showing the appearance of the light probe Front view showing the tip of the light probe Front view of rotary shutter Sequence diagram showing switching of light introduced into body cavity (A) Sequence diagram (B) showing switching of captured image, sequence diagram (C) showing switching of transferred image signal, and timing of spectroscopic measurement Sequence diagram (D) Mapping diagram (a) of first memory and second memory and layout diagram of video signal (b) Line memory structure diagram (a) and third memory mapping diagram (b) The figure which shows the screen which is displayed on the monitor

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Endoscope 10f Forceps channel 12 Objective lens 13 Image sensor 15 Excitation light cut filter 17a Switch 17b Switch 20 Light source device 32 Excitation light source 34 Excitation light cut filter 35 Spectroscope 40 System controller 41 Timing controller 43 First memory 44 Scan converter 51 Line memory 52 Second memory 55 Third memory 60 Monitor

Claims (4)

A fluorescence observation device that introduces excitation light into a body cavity and spectroscopically measures fluorescence emitted from a living tissue of a subject excited by the excitation light,
It has an objective optical system and an illumination window at its distal end, and has a hollow channel that passes between the proximal end and the distal end, and a body cavity insertion portion that incorporates a light guide that guides light from the proximal end to the illumination window. With a scope,
An imaging device that sequentially captures an image of the test part formed by the objective optical system, converts the image into a video signal, and outputs the video signal;
A light probe that is inserted into the channel and emits light introduced from the proximal end thereof from the distal end; and
A visible light source that emits visible illumination light;
An illumination optical system for guiding the optical path of visible illumination light emitted from the visible light source to the proximal end of the light guide;
An excitation light source that emits excitation light in a wavelength band that excites biological tissue and emits fluorescence;
An optical path switching optical element that selectively switches the optical path of the excitation light to one of an optical path that reaches the proximal end of the light probe and an optical path that intersects the optical path of the visible illumination light;
An optical path combining optical element that combines both optical paths at an intersection of the optical path of the visible illumination light and the optical path of the excitation light switched by the optical path switching optical element;
An excitation light cut filter that blocks only the excitation light on the optical path from the objective optical system to the imaging device;
A fluorescence observation apparatus comprising: a spectroscopic measurement unit configured to perform spectroscopic measurement of the fluorescence while the optical path switching optical element switches the optical path of the excitation light to an optical path reaching the base end of the light probe. A fluorescence observation device that introduces excitation light into a body cavity and spectroscopically measures fluorescence emitted from a living tissue of a subject excited by the excitation light,
It has an objective optical system and an illumination window at its distal end, and has a hollow channel that passes between the proximal end and the distal end, and a body cavity insertion portion that incorporates a light guide that guides light from the proximal end to the illumination window. With a scope,
An imaging device that sequentially captures an image of the test part formed by the objective optical system, converts the image into a video signal, and outputs the video signal;
A light probe that is inserted into the channel and emits light introduced from the proximal end thereof from the distal end; and
A visible light source that emits visible illumination light;
An illumination optical system for guiding the optical path of visible illumination light emitted from the visible light source to the proximal end of the light guide;
An excitation light source that emits excitation light in a wavelength band that excites biological tissue and emits fluorescence;
An optical path switching optical element that selectively switches the optical path of the excitation light to one of an optical path that reaches the proximal end of the light probe and an optical path that intersects the optical path of the visible illumination light;
An optical path combining optical element that combines both optical paths at an intersection of the optical path of the visible illumination light and the optical path of the excitation light switched by the optical path switching optical element;
An excitation light cut filter that blocks only the excitation light on the optical path from the objective optical system to the imaging device;
Spectral measuring means for spectroscopically measuring the fluorescence while the optical path switching optical element switches the optical path of the excitation light to the optical path reaching the base end of the light probe;
An operation member operated by an operator;
In response to an operation on the operation member, the first state in which only the visible illumination light is introduced into the light guide and the introduction of the excitation light into the light guide and the light probe is stopped, and the optical path switching element A second state in which only the excitation light is introduced into the light guide after switching the optical path of the excitation light to an optical path intersecting the optical path of the visible illumination light, and the optical path of the excitation light is written by the optical path switching element. A third state in which the excitation light is introduced into the proximal end of the light probe after switching to the optical path leading to the proximal end of the probe and the introduction of the visible illumination light into the light guide is selectively performed; A control unit for switching;
Expansion means for expanding a spectral measurement result by the spectral measurement means into an image of a graph;
A converter for generating a video signal for displaying the video by the video signal and the image developed by the developing means side by side;
A fluorescence observation apparatus comprising: a monitor that performs screen display based on the video signal. The light probe is configured by bundling a first optical fiber that transmits the excitation light and a second optical fiber that transmits the fluorescence at the distal end side, and at the base end, the first optical fiber is bundled with the first optical fiber. The fluorescence observation apparatus according to claim 1, wherein the optical fiber is separated from the second optical fiber. A body cavity insertion portion including an objective optical system and an illumination window at the distal end, a hollow channel passing through the proximal end and the distal end, and a light guide for guiding light from the proximal end to the illumination window; An imaging device that sequentially captures an image of the test part formed by the objective optical system, converts it into a video signal, and outputs it, and excitation that blocks only the excitation light on the optical path from the objective optical system to the imaging device The proximal end of the light guide in an endoscope having a light cut filter is connected, and the proximal end of a light probe that is inserted through the channel and emits light introduced from the proximal end from the distal end is connected. A light source device,
A visible light source that emits visible illumination light;
An illumination optical system for guiding the optical path of visible illumination light emitted from the visible light source to the proximal end of the light guide;
An excitation light source that emits excitation light in a wavelength band that excites biological tissue and emits fluorescence;
An optical path switching optical element that selectively switches the optical path of the excitation light to one of an optical path that reaches the proximal end of the light probe and an optical path that intersects the optical path of the visible illumination light;
A light source device comprising: an optical path combining optical element that combines both optical paths at an intersection of the optical path of the visible illumination light and the optical path of the excitation light switched by the optical path switching optical element.