JP2012217670A - Endoscope diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope diagnostic apparatus which takes an image of autofluorescence having weak optical power at a high S/N ratio.SOLUTION: The endoscope diagnostic apparatus includes: a light source LD emitting exciting light with a prescribed wavelength and making a plurality of autofluorescence simultaneously emit; a turret 74 having a primary filter through which primary light including the emission wavelength range of a target autofluorescence is transmitted, and a secondary filter through which secondary light within the wavelength range of the primary light and not including the emission wavelength range of the target autofluorescence is transmitted; image elements 58B taking images of the primary and secondary autofluorescent synthetic light simultaneously emitted by irradiating a subject person with the exciting light and divided into spectrum with the primary and secondary filters to obtain the images of the primary and secondary autofluorescence; and an image processing part 70 which adjusts an effective amount of exposed light received with the pixels of the image elements respectively through the primary and secondary filters when taking the image of the synthetic light, subjects the primary and secondary autofluorescent images to image processing, extracts the target autofluorescent image corresponding to the target autofluorescence and displays the images on a display device.

Description

  The present invention relates to an endoscopic diagnostic apparatus that captures an autofluorescence image by capturing autofluorescence emitted from an autofluorescent substance contained in an observation region of a subject (living body).

  Conventionally, normal light (white light) emitted from a light source device is guided to the distal end portion of the endoscope, irradiated on the subject's observation area, and the reflected light is imaged to obtain a normal light image (white light image). Is used, and an endoscope apparatus that performs normal light observation (white light observation) is used. On the other hand, in recent years, in addition to normal light observation, excitation light (special light) for autofluorescence observation is irradiated to the subject's observation area, and the autofluorescence emitted from the autofluorescent material is imaged and the autofluorescence is imaged. An endoscope apparatus that acquires a fluorescent image (special light image) and performs autofluorescence observation (special light observation) is used.

  As an endoscope apparatus for performing autofluorescence observation, for example, there is Patent Document 1. In Patent Document 1, a light source unit sequentially irradiates a living body with light in a visible region and a plurality of excitation lights having different wavelength regions for exciting a fluorescent substance, and the wavelength of the excitation light is obtained by an excitation wavelength selection filter. Visible region light and autofluorescence are transmitted while blocking the region light, and the visible region light and autofluorescence emitted from the living body in time series are acquired by the imaging device, and the visible light image and the fluorescence image are monitored. An endoscope apparatus to be displayed is described.

JP 2006-296635 A

  In Patent Document 1, since autofluorescence sequentially excited one by one is received by a one-channel narrow-band wavelength filter (excitation wavelength selection filter), it is difficult to capture autofluorescence originally having a weak light intensity. there were.

  In contrast, for example, if a plurality of types of autofluorescence are simultaneously excited and the combined light is received by a broadband wavelength filter, a sufficient S / N (signal / noise) can be obtained in the captured autofluorescence image. There was a problem that it was difficult to separate autofluorescence.

  In addition, for example, when imaging autofluorescence using an image sensor such as a color CCD (solid-state image sensor), the arrangement of the spectral filters is an arrangement suitable for imaging normal light (a general Bayer array is , Designed to match the sensitivity of the human eye, blue (B) 1 pixel, red (R) 1 pixel for 2 green (G) pixels), but the light intensity is weak and for each wavelength band However, there is a problem that the arrangement is not optimal for separating different autofluorescent components.

  An object of the present invention is to provide an endoscopic diagnostic apparatus capable of imaging autofluorescence with weak light intensity with high S / N.

In order to achieve the above object, the present invention provides a light source that emits excitation light of a predetermined wavelength that simultaneously emits a plurality of autofluorescences,
A first filter having a spectral transmission characteristic that transmits first light including the emission wavelength range of the autofluorescence of interest;
A second filter having spectral transmission characteristics that transmits second light that is within the wavelength range of the first light and does not include the emission wavelength range of the target autofluorescence;
By irradiating the observation region of the subject with the excitation light, the combined light of the first and second autofluorescences simultaneously emitted from the observation region and dispersed by the first and second filters. An image sensor that captures images to obtain first and second autofluorescence images;
An exposure amount adjustment unit that adjusts an effective exposure amount of light received by the pixels of the image sensor through the first and second filters, respectively, during imaging of the combined light;
An image processing unit that performs image processing on the first and second autofluorescence images, extracts a noticed autofluorescence image corresponding to the noticeable autofluorescence, and displays the noticed autofluorescence image on a display device; An endoscopic diagnosis apparatus is provided.

Here, the first and second filters are filters provided on a light receiving surface of the image sensor,
The image sensor is an image sensor that images the combined light simultaneously through the first and second filters,
It is preferable that the exposure amount adjusting unit adjusts the effective exposure amount by increasing the number of pixels of the second filter than the number of pixels of the first filter.

Further, the first and second filters are filters sequentially inserted on an optical path of light received by the imaging device,
The image sensor is an image sensor that images the combined light in a surface sequential manner through the first or second filter inserted in the optical path,
It is preferable that the exposure amount adjusting unit adjusts the effective exposure amount by extending an exposure time at the time of imaging the second autofluorescence rather than the first autofluorescence.

Further, the first and second filters are filters sequentially inserted on an optical path of light received by the imaging device,
The image sensor is an image sensor that images the combined light in a surface sequential manner through the first or second filter inserted in the optical path,
Preferably, the exposure amount adjusting unit adjusts the effective exposure amount by increasing a driving current amount of the light source at the time of imaging the second autofluorescence than the first autofluorescence.

  Moreover, it is preferable that the said image process part is what extracts the said attention autofluorescence image by calculating the difference of the said 1st and 2nd autofluorescence image.

  Moreover, it is preferable that the light source emits a plurality of excitation lights having different wavelengths that simultaneously emit a plurality of autofluorescences.

A second light source that emits white light;
A second imaging element that captures reflected light reflected from the observation region by irradiating the observation region of the subject with the white light, and acquires a white light image;
It is preferable that the image processing unit is configured to create a composite image by combining the white light image and the focused autofluorescence image and display the composite image on the display device.

  The image processing unit assigns the noted autofluorescent image to the G channel of the composite image and the white light image to the B and R channels of the composite image, and displays the composite image in pseudo color. Is preferred.

  The noted autofluorescence is preferably autofluorescence emitted from tryptophan, FAD, or porphyrin.

  In the present invention, the synthesized light of autofluorescence simultaneously emitted from a plurality of autofluorescent substances included in the observation region is imaged through a broadband filter, and the two autofluorescence images obtained are image-processed to extract a noticed autofluorescence image. . Therefore, according to the present invention, compared to the case where autofluorescence emitted from one type of autofluorescent substance is imaged through a narrow band filter, the light intensity is large and the S / N can be significantly improved. is there.

1 is an external view of an embodiment showing a configuration of an endoscope diagnosis apparatus according to the present invention. It is a block diagram of 1st Embodiment showing the internal structure of the endoscope diagnostic apparatus shown in FIG. It is a conceptual diagram showing the mode of the front-end | tip part of the endoscope insertion part of the endoscope diagnostic apparatus shown in FIG. It is an example of a graph showing the wavelength range of autofluorescence emitted from three kinds of autofluorescent substances. It is a graph of an example showing the spectral transmission characteristic of the 1st and 2nd filter. It is a conceptual diagram of an example showing the pixel arrangement | sequence of a 1st and 2nd filter. It is a conceptual diagram of an example showing the flow of processing in the case of the autofluorescence observation mode. It is a graph of another example showing the spectral transmission characteristic of the 1st and 2nd filter. It is a block diagram of 3rd Embodiment showing the internal structure of the endoscope diagnostic apparatus shown in FIG. It is a block diagram of the turret used as an example of a 1st and 2nd filter.

  Hereinafter, based on a preferred embodiment shown in the accompanying drawings, an endoscope diagnosis apparatus according to the present invention will be described in detail.

  FIG. 1 is an external view of an embodiment showing the configuration of an endoscope diagnosis apparatus according to the present invention, and FIG. 2 is a block diagram of the first embodiment showing the internal configuration. The endoscopic diagnosis apparatus 10 shown in these drawings includes a light source device 12 that emits normal light or excitation light for autofluorescence observation, and guides light emitted from the light source device 12 to the observation region of the subject. An endoscope apparatus 14 that irradiates and images reflected light or autofluorescence from a subject; a processor apparatus 16 that performs image processing on an image captured by the endoscope apparatus 14 and outputs an endoscope image; The display device 18 that displays an endoscopic image output from the processor device 16 and the input device 20 that receives an input operation are configured.

  Here, the endoscope diagnostic apparatus 10 irradiates a subject with normal light (white light), images the reflected light, and displays (observes) a normal light image (white light image). (White light observation mode) and auto-fluorescence observation mode (special light image) that irradiates the subject with excitation light (special light) for auto-fluorescence observation and images the auto-fluorescence and displays the auto-fluorescence image (special light image) Light observation mode). Each observation mode is appropriately switched based on an instruction input from the changeover switch 66 of the endoscope apparatus 14 or the input device 20.

  The light source device 12 includes a light source control unit 22, two types of laser light sources LD 1 and LD 2 that emit laser beams having different center wavelengths, a combiner (multiplexer) 24, and a coupler (demultiplexer) 26. ing.

  In the present embodiment, the laser light sources LD1 and LD2 emit narrowband light in a predetermined wavelength range (for example, center wavelength ± 10 nm) having center wavelengths of 330 nm and 445 nm, respectively. The laser light source LD1 is an excitation for simultaneously emitting autofluorescence from a plurality of autofluorescent substances, for example, tryptophan, FAD (Flavin Adenine Dinucleotide), porphyrin, etc. included in the observation region of the subject. It is a light source that emits light. In addition, the laser light source LD2 is a light source that generates excitation light for generating white light (pseudo white light) from a phosphor, as will be described later.

  As shown in FIG. 4, tryptophan emits autofluorescence in a wavelength range of about 300 to 380 nm when irradiated with excitation light having a predetermined center wavelength included in a wavelength range of about 250 to 360 nm. The FAD emits autofluorescence in a wavelength range of about 450 to 550 nm when irradiated with excitation light having a predetermined center wavelength included in a wavelength range of about 330 to 400 nm. Porphyrin emits autofluorescence of about 610 to 640 nm when irradiated with excitation light of a predetermined center wavelength included in a wavelength range of about 350 to 550 nm.

  In the case of this embodiment, when the subject is irradiated with laser light having a central wavelength of 330 nm as excitation light for autofluorescence observation, autofluorescence is emitted simultaneously from tryptophan and FAD. No fluorescence is emitted.

  In this embodiment, tryptophan, FAD, and porphyrin will be described as examples of the autofluorescent material to be extracted from the autofluorescent synthetic light emitted simultaneously from a plurality of autofluorescent materials. It is not limited to substances.

  The laser light sources LD1 and LD2 are individually subjected to on / off control and light amount control by the light source control unit 22 controlled by the control unit of the processor device 16 described later, and the light emission timing and light amount ratio of each laser light source LD1 and LD2 are as follows. It can be changed freely. As the laser light sources LD1 and LD2, a broad area type InGaN laser diode can be used, and an InGaNAs laser diode, a GaNAs laser diode, or the like can also be used.

  The normal light source for generating the normal light is not limited to the combination of the excitation light and the phosphor, and any light source that emits white light may be used. For example, a xenon lamp, a halogen lamp, a white LED (light emitting diode) Etc. can also be used. An excitation light source for generating excitation light for autofluorescence observation is not limited to a laser light source (semiconductor laser), and excitation light having sufficient intensity to excite an autofluorescent substance to emit autofluorescence. Various light sources that can be irradiated, for example, a combination of a white light source and a band limiting filter can be used.

  In addition, the wavelength of excitation light for normal light observation (center wavelength, wavelength range of narrowband light) is not particularly limited, and all excitation light having a wavelength capable of generating pseudo white light from a phosphor can be used. It is. The wavelength of the excitation light for autofluorescence observation is not particularly limited, and all excitation light having a wavelength capable of simultaneously exciting a plurality of autofluorescent substances to emit autofluorescence can be used. Light having a wavelength of ˜360 nm or light having a wavelength of 350 to 400 nm can be preferably used.

  Further, the present invention is not limited to irradiating the subject with excitation light of one kind of central wavelength and simultaneously emitting autofluorescence from a plurality of autofluorescent materials, and simultaneously emitting a plurality of autofluorescence from the light source device 12. Therefore, a configuration may be adopted in which a plurality of excitation lights having different center wavelengths are irradiated simultaneously. In the present embodiment, the normal light source and the excitation light source are provided separately, but both may be configured by a common light source.

  In the normal light observation mode, the light source controller 22 turns off the laser light source LD1 and turns on the laser light source LD2. The light source control unit 22 turns on the laser light source LD1 and turns off LD2 in the auto-fluorescence observation mode.

  Laser light emitted from each of the laser light sources LD1 and LD2 is input to the corresponding optical fiber via a condenser lens (not shown), combined by a combiner 24, and demultiplexed into four systems of light by a coupler 26. Is transmitted to the connector portion 32A. The combiner 24 and the coupler 26 are configured by a half mirror, a reflection mirror, or the like. However, the present invention is not limited to this, and the laser light from each of the laser light sources LD1 and LD2 may be sent directly to the connector portion 32A without using the combiner 24 and the coupler 26.

  Subsequently, the endoscope apparatus 14 emits four systems (four lights) of light (normal light or excitation light for autofluorescence observation) from the distal end of the endoscope insertion portion inserted into the subject. And an imaging optical system of two systems (two eyes) that captures an endoscopic image of the observation region. The endoscope apparatus 14 includes an endoscope insertion section 28, an operation section 30 that performs an operation for bending and observing the distal end of the endoscope insertion section 28, and the endoscope apparatus 14 as a light source device 12 and a processor. Connector portions 32A and 32B that are detachably connected to the device 16 are provided.

  The endoscope insertion portion 28 includes a flexible soft portion 34, a bending portion 36, and a distal end portion (hereinafter also referred to as an endoscope distal end portion) 38.

  The bending portion 36 is provided between the flexible portion 34 and the distal end portion 38 and is configured to be bent by a turning operation of the angle knob 40 disposed in the operation portion 30. The bending portion 36 can be bent in an arbitrary direction and an arbitrary angle in accordance with a portion of the subject in which the endoscope apparatus 14 is used, and the endoscope distal end portion 38 is directed to a desired observation portion. be able to.

  Although not shown, various channels such as a forceps channel for inserting a tissue collection treatment instrument and the like and a channel for air supply / water supply are provided inside the operation unit 30 and the endoscope insertion unit 28. It has been.

  As shown in FIG. 3, two systems of illumination windows 42 </ b> A and 42 </ b> B that irradiate light to the observation region, and reflected light or autofluorescence 1 from the observation region are imaged on the distal end surface of the endoscope distal end portion 38. In addition to the system observation window 44, a forceps port 45 and the like are arranged.

  Two systems of optical fibers 46A and 48A are housed in the back of the illumination window 42A. The optical fibers 46A and 48A are laid from the light source device 12 to the scope distal end portion 38 via the connector portion 32A. An optical system such as a lens 50A is attached to the tip of the optical fiber 46A (on the illumination window 42A side). On the other hand, a phosphor 54A is disposed at the tip of the optical fiber 48A, and an optical system such as a lens 52A is attached to the tip of the phosphor 54A.

  Similarly, in the back of the illumination window 42B, there are two systems, an optical fiber 46B having an optical system such as a lens 50B at the tip, and an optical fiber 48B having an optical system such as a phosphor 54B and a lens 52B at the tip. An optical fiber is housed.

The phosphors 54A and 54B absorb a part of the blue laser light from the laser light source LD2 and emit a plurality of kinds of fluorescent materials (for example, YAG-based fluorescent materials, BAM (BaMgAl ₁₀ O ₁₇ ), etc.) that emit light from green to yellow. A fluorescent substance). When excitation light for normal light observation is irradiated onto the phosphors 54A and 54B, green to yellow excitation light (fluorescence) emitted from the phosphors 54A and 54B and the phosphors 54A and 54B are transmitted without being absorbed. Combined with the blue laser light, white light (pseudo white light) is generated.

  The illumination optical systems on the illumination window 42A side and the illumination window 42B side have the same configuration and operation, and illumination unevenness can be prevented by irradiating the illumination windows 42A and 42B simultaneously with equivalent illumination light. Different illumination light can be irradiated from the illumination windows 42A and 42B. It is not essential to have an illumination optical system that emits four systems of illumination light. For example, an illumination optical system that emits two or one system of illumination light can realize the same function.

  On the other hand, an optical system such as a lens 56 is attached to the back of the observation window 44, and a half mirror 57 is provided to the back of the lens 56. A CCD (Charge Coupled Device) image sensor that acquires image information of an observation region is provided at the tip of the optical path of the transmitted light that passes through the half mirror 57 and the tip of the optical path of the reflected light that is reflected by the half mirror 57. Imaging elements 58A and 58B such as CMOS (Complementary Metal-Oxide Semiconductor) image sensors are attached. The image sensor 58A is for normal light observation, and the image sensor 58B is for autofluorescence observation. Since the light intensity (emission intensity) of the autofluorescence is weak, in this embodiment, the image sensor 58B for autofluorescence observation has a higher sensitivity than the image sensor 58A for normal light observation.

  Note that the light receiving light is not limited to the half mirror 57, and the received light may be distributed to the image sensor 58A or the image sensor 58B, for example, by putting a total reflection mirror in and out of the optical path of the received light.

  The image sensor 58A receives transmitted light that passes through the half mirror 57 at a light receiving surface (imaging surface), photoelectrically converts the received light, and outputs an image signal (analog signal). A plurality of sets of pixels are arranged in a matrix, with one set of pixels of three colors, pixels and B pixels. On the light receiving surface of the image sensor 58A, the reflected light in the wavelength range of about 370 to 720 nm of visible light from the observation region is divided into three wavelength regions corresponding to the R pixel, G pixel, and B pixel, respectively. R color filters, G color filters, and B color filters each having a spectral transmission characteristic to be transmitted are provided.

  Note that it is not essential to simultaneously capture R, G, and B images using a color image sensor as the image sensor 58A, and a monochrome image sensor and R, G, and B colors. In combination with a color filter, R, G, and B color images may be taken in a frame sequential manner.

  The imaging element 58B receives reflected light reflected by the half mirror 57 at the light receiving surface, photoelectrically converts the received light, and outputs an imaging signal (analog signal). The first pixel and the second pixel As a set, a plurality of sets of pixels are arranged in a matrix. On the light receiving surface of the image sensor 58B, as shown in FIG. 5, the autofluorescence emitted from the autofluorescent material corresponding to the first pixel and the second pixel, respectively, in the wavelength range of about 335 to 640 nm and about 365 First and second filters having spectral transmission characteristics that transmit autofluorescence in the wavelength range of ˜640 nm are provided.

  Here, by irradiating the subject's observation area with excitation light for autofluorescence observation, autofluorescence is simultaneously emitted from a plurality of autofluorescent substances contained in the observation area, and all autofluorescence is synthesized. Consider a case where light having a wavelength range of about 335 to 640 nm is emitted. In this case, the effective exposure amount of the combined light received by the first and second pixels through the first and second filters of the image sensor 58B (the spectral transmittance of the first filter and the light receiving sensitivity of the first band image). The product and the product of the spectral transmittance of the second filter and the light reception sensitivity of the second band image) are larger in the first pixel than in the second pixel by the wider wavelength range in which light can be received.

  In this embodiment, the ratio of the effective exposure amounts of the first and second pixels is 3: 1, and the pixels of the first and second filters have an effective exposure amount of both as shown in FIG. They are arranged in a ratio of 1: 3 so as to cancel the difference. In the figure, the pixels of the first and second filters are described as “1” and “2”, respectively. In addition, a set of four pixels indicated by broken lines in the figure is taken as one set, and a plurality of sets are arranged by changing the arrangement within the set. Thereby, the effective exposure amounts of the first and second pixels are adjusted to be substantially the same. Note that it is not essential to completely cancel out the difference in effective exposure amount.For example, by increasing the number of pixels of the filter having the smaller effective exposure amount than the number of pixels of the filter having the larger effective exposure amount, It is only necessary to reduce the difference between the effective exposure amounts of the two as much as possible.

  As described above, adjusting the effective exposure amounts of the first and second pixels by adjusting the ratio of the number of pixels of the first and second filters is an embodiment of the exposure amount adjusting unit of the present invention. Is.

  Light guided from the light source device 12 by the optical fibers 46A and 46B and 48A and 48B is irradiated from the endoscope distal end portion 38 toward the observation region of the subject. Then, reflected light from the observation region irradiated with light or autofluorescence emitted from the autofluorescent material in the observation region is imaged by the lens 56 on the light receiving surfaces of the image sensors 58A and 58B, and the image sensor 58A. , 58B are photoelectrically converted and imaged. From the imaging elements 58A and 58B, an imaging signal (analog signal) of the imaged area of the subject to be imaged is output.

  Here, in the normal light observation mode, excitation light for normal light observation emitted from the laser light source LD2 is guided by the optical fibers 48A and 48B and irradiated to the phosphors 54A and 54B, and from the phosphors 54A and 54B. The emitted white light is irradiated to the subject's observation area from the illumination windows 42A and 42B. Then, the reflected light from the observation region of the subject irradiated with white light is collected by the lens 56, dispersed by the color filter, and a normal light image is captured by the image sensor 58A.

  On the other hand, in the autofluorescence observation mode, the excitation light for autofluorescence observation emitted from the laser light source LD1 is guided by the optical fibers 46A and 46B, and is passed from the endoscope distal end portion 38 to the observation region of the subject. Irradiated toward. And the synthetic light of the autofluorescence emitted simultaneously from the plurality of autofluorescent substances included in the observation region of the subject irradiated with the excitation light is condensed by the lens 56, and is dispersed by the first and second filters, First and second autofluorescence images are captured by the image sensor 58B.

  The excitation light for autofluorescence observation is laser light having a center wavelength of 330 nm, and the first autofluorescence image is captured through the first filter by receiving synthesized light in a wavelength range of about 335 to 640 nm. Therefore, the first autofluorescence image mainly contains tryptophan and FAD autofluorescence components. On the other hand, the second autofluorescence image is picked up by receiving the combined light in the wavelength range of about 365 to 640 nm through the second filter. Therefore, the second autofluorescence image mainly includes the autofluorescence component of FAD.

  Note that the image sensor 58B is not provided with a filter having a spectral transmission characteristic that transmits light including the wavelength range of excitation light for autofluorescence observation. For this reason, excitation light for autofluorescence observation with a central wavelength of 330 nm is cut off and is not received by the light receiving surface of the image sensor 58B.

  Imaging signals (analog signals) of images (normal light images and autofluorescence images) output from the imaging elements 58A and 58B are input to the A / D converters 64A and 64B through the scope cables 62A and 62B, respectively. The A / D converters 64A and 64B convert image signals (analog signals) from the image sensors 58A and 58B into image signals (digital signals), respectively. The converted image signal is input to the image processing unit 70 of the processor device 16 via the connector unit 32B.

  Subsequently, the processor device 16 includes a control unit 68, an image processing unit 70, and a storage unit 72. The display device 18 and the input device 20 are connected to the control unit 68. The processor device 16 controls the light source control unit 22 of the light source device 12 based on an instruction input from the changeover switch 66 or the input device 20 of the endoscope device 14, and an image signal input from the endoscope device 14. Is processed, a display image is generated and output to the display device 18.

  The control unit 68 controls the operations of the image processing unit 70 and the light source control unit 22 of the light source device 12 based on an instruction from the changeover switch 66 of the endoscope apparatus 14 or an input device 20, for example, an instruction such as an observation mode. To do.

  Under the control of the control unit 68, the image processing unit 70 performs a predetermined process on an image signal input from the endoscope apparatus 14 according to the image type of the normal light image and the autofluorescence image based on the observation mode. Apply image processing. The image processing unit 70 includes a normal light image processing unit 70A and an autofluorescence image processing unit 70B.

  The normal light image processing unit 70A performs predetermined image processing suitable for the normal light image on the image signal (image data) of the normal light image supplied from the A / D converter 64A in the normal light observation mode. The normal light image signal (normal light image) is output (generated).

  The autofluorescence image processing unit 70B performs predetermined image processing suitable for the autofluorescence image on the image signal (image data) of the autofluorescence image supplied from the A / D converter 64B in the autofluorescence observation mode. To output (generate) an autofluorescence image signal (autofluorescence image).

  The image signal processed by the image processing unit 70 is sent to the control unit 68. In the control unit 68, the normal light image or a composite image of the normal light image and the autofluorescence image is displayed on the display device 18 based on the normal light image signal and the autofluorescence image signal according to the observation mode. Further, under the control of the control unit 68, the normal light image signal and the autofluorescence image signal are stored in the storage unit 72 including a memory or a storage device, for example, in units of one (one frame) image as necessary. Is done.

  Next, the operation of the endoscope diagnosis apparatus 10 will be described.

  In the normal light observation mode, under the control of the light source control unit 22, the laser light source LD1 is turned off and the laser light source LD2 is turned on. Laser light having a central wavelength of 445 nm emitted from the laser light source LD2 is applied to the phosphors 54A and 54B, and white light is emitted from the phosphors 54A and 54B. The white light emitted from the phosphors 54A and 54B is irradiated to the subject, the reflected light is received by the image sensor 58A, and a normal light image including R, G, and B channel image signals is captured. The normal light image is displayed in color based on the image signals of the B, G, and R channels.

  In the case of the autofluorescence observation mode, for example, imaging is repeatedly performed in units of 2 frames. Of the two frames, the first frame is the same observation mode as the normal light observation mode, and the second frame is an observation mode unique to the autofluorescence observation mode.

  As shown in FIG. 7, first, in the normal light observation mode of the first frame, as described above, the subject is irradiated with white light (S1), and normal light including R, G, B channel image signals is included. An image is captured (S2). Then, the normal light image signal is stored in the storage unit 72 under the control of the control unit 68.

  Subsequently, in the auto-fluorescence observation mode of the second frame, the laser light source LD1 is turned on and the LD2 is turned off under the control of the light source control unit 22. When a laser beam (excitation light) having a central wavelength of 330 nm emitted from the laser light source LD1 is irradiated onto the subject's observation region (S3), autofluorescence is emitted simultaneously from tryptophan and FAD contained in the observation region. (S4). Then, the combined light of both autofluorescences is received by the image sensor 58B, and the first and second autofluorescence images are taken simultaneously (S5).

  As described above, the effective exposure amount of the combined light received by the first and second pixels of the image sensor 58B through each of the first and second filters of the image sensor 58B is equivalent to the wide wavelength range that can be received. There are more first pixels than second pixels. However, since the pixels of the first and second filters are arranged at a ratio that cancels the difference between the effective exposure amounts of the first and second filters, the effective exposure amounts of the first and second pixels are adjusted to be substantially the same. (S6).

  As described above, the first autofluorescence image mainly contains tryptophan and FAD autofluorescence components. On the other hand, the second autofluorescence image mainly includes an autofluorescence component of FAD. The autofluorescence image processing unit 70B subtracts the second autofluorescence image from the first autofluorescence image and calculates the difference between the two. Thereby, the autofluorescence image corresponding to the autofluorescence of tryptophan is extracted (S7).

  Note that calculating the difference between the first and second autofluorescent images in order to extract the noted autofluorescent image is not limited. For example, various image processing including matrix calculation and division may be performed. You may extract an attention autofluorescence image by giving to 2 autofluorescence images.

  The autofluorescence image has a very weak light intensity compared to the normal light image. Therefore, as in Patent Document 1, when autofluorescence emitted from one type of autofluorescent material is imaged through a narrow band filter, there is a problem that the light intensity is very small and the S / N is deteriorated.

  On the other hand, in the endoscope diagnostic apparatus 10 according to the present embodiment, two autofluorescence images acquired by imaging the autofluorescent synthesized light simultaneously emitted from a plurality of autofluorescent substances included in the observation region through a broadband filter. And subject autofluorescence image is extracted. Therefore, compared with the case where autofluorescence emitted from one type of autofluorescent material is imaged through a narrow band filter, there is an effect that the light intensity is large and the S / N can be greatly improved.

  Further, in order to allow the autofluorescence image processing unit 70B to appropriately observe the autofluorescence image in the combined image of the normal light image and the autofluorescence image, the characteristics of both of them (γ value, luminance level, contrast, etc.) A signal amplification process or the like for appropriately adjusting the balance is performed (S8).

  Then, the normal light image corresponding to the normal light image signal stored in the storage unit 72 and the tryptophan or FAD autofluorescence image are combined and the combined image of both is displayed on the display device 18. Here, the composite image is simulated by assigning the image signal of the noticed autofluorescence image to the G channel of the composite image and the image signals of the R channel and B channel of the normal light image to the R channel and B channel of the composite image, respectively. Color display is performed (S8).

  In the case of the autofluorescence observation mode, it is not essential to repeat imaging in units of 2 frames. In addition, when the synthesized image is displayed in pseudo color, it is arbitrary which image signal of which image is assigned to which color channel of the synthesized image. In addition, it is not essential to display the composite image in pseudo color. For example, the normal light image and the autofluorescence image may be displayed in a superimposed manner or displayed side by side.

  Next, the case where the autofluorescence of porphyrin is extracted from a plurality of synthesized light of autofluorescence will be described as the endoscope diagnosis apparatus of the second embodiment.

  In the endoscope diagnostic apparatus of the second embodiment, in the autofluorescence observation mode, laser light with a center wavelength of 380 nm (or 365 nm) is emitted from the LD 1 of the light source device 12 as excitation light for autofluorescence observation. Is done.

  On the other hand, on the light receiving surface of the image sensor 58B, as shown in FIG. 8, autofluorescence emitted from the autofluorescent material corresponding to the first pixel and the second pixel, respectively, in the wavelength range of about 450 to 600 nm and First and second filters having spectral transmission characteristics that transmit autofluorescence in a wavelength range of about 450 to 650 nm are provided. Similarly, the pixels of the first and second filters are arranged at a ratio that cancels out the difference in effective exposure amount between the first and second pixels.

  In the endoscopic diagnostic apparatus of the second embodiment, in the autofluorescence observation mode, a laser beam (excitation light) having a center wavelength of 380 nm emitted from the laser light source LD1 is irradiated on the observation region of the subject. Autofluorescence is emitted simultaneously from FAD and porphyrin contained in the observed region. Then, the combined light of both autofluorescences is received by the image sensor 58B, and the first and second autofluorescence images are taken simultaneously.

  The first autofluorescence image mainly includes autofluorescence components of FAD and porphyrin, and the second autofluorescence image mainly includes autofluorescence components of FAD. The autofluorescence image processing unit 70B subtracts the first autofluorescence image from the second autofluorescence image and calculates the difference between the two, thereby extracting the autofluorescence image corresponding to the porphyrin autofluorescence. The subsequent operation is the same as that in the first embodiment.

  As described above, the autofluorescent component of porphyrin can be extracted from a plurality of autofluorescent synthetic lights. Further, the present invention is not limited to this, and the autofluorescent component of any autofluorescent substance can be extracted from any combination of synthesized light.

  Next, an endoscope diagnosis apparatus according to a third embodiment will be described.

  FIG. 9 is a block diagram of the third embodiment showing the internal configuration of the endoscope diagnosis apparatus shown in FIG. The endoscope diagnosis apparatus 80 according to the third embodiment has a light receiving surface in the case of the endoscope diagnosis apparatus 10 according to the first embodiment in which the imaging element 58B is a monochrome imaging element and is in the autofluorescence observation mode. The first and second filters are sequentially inserted on the optical path of the light (reflected light) received by the light source.

  The first and second filters are configured by a turret 74 that is inserted vertically on the optical path of the reflected light and whose rotation is controlled by a rotation control unit (not shown) controlled by the control unit 68. As shown in FIG. 10, the turret 74 is formed with a first filter portion 76 and a second filter portion 78. In the auto fluorescence observation mode, the turret 74 is rotated, whereby the first filter unit 76 and the second filter unit 78 are sequentially inserted on the optical path.

  The first and second filters are not limited to the turret 74, and for example, a first filter and a second filter may be provided separately, and each may be sequentially put in and out of the optical path of the reflected light.

  In the endoscope diagnosis apparatus 80 according to the third embodiment, in the autofluorescence observation mode, the first filter unit 76 and the second filter unit 78 are sequentially inserted on the optical path of the reflected light, and the first image sensor 58B causes The second autofluorescence is imaged in the frame order.

  As in the case of the first embodiment, the first filter unit 76 and the second filter unit 78 are emitted from the autofluorescent material, and have autofluorescence in the wavelength range of about 335 to 640 nm and autologous in the wavelength range of about 365 to 640 nm. Spectral transmission characteristics that transmit fluorescence.

  In the autofluorescence observation mode, the first and second filters are controlled by the control unit 68 to control the pixels of the image sensor 58B (hereinafter referred to as the first and second filters) when the first and second autofluorescence images are captured. The insertion time is adjusted so as to cancel the difference in effective exposure amount (referred to as “pixel”), and is inserted into the optical path of the reflected light. Thereby, when the first and second autofluorescence are imaged by the image sensor 58B, the exposure time of the second autofluorescence is adjusted to be longer than that of the first autofluorescence.

  Similarly, when the ratio of the effective exposure amounts of the first and second pixels is 3: 1, the insertion time of the second filter unit 78 is set to three times the insertion time of the first filter unit 76. Thereby, the effective exposure amounts of the first and second pixels are adjusted to be substantially the same. Note that it is not essential to completely cancel the difference in the effective exposure amount between the two, and by making the insertion time for the smaller effective exposure amount longer than the insertion time for the larger effective exposure amount, It only has to be as small as possible.

  As described above, adjusting the effective exposure amounts of the first and second pixels by adjusting the insertion times of the first filter unit 76 and the second filter unit 78 is an embodiment of the exposure amount adjustment unit of the present invention. It becomes a form.

  In the endoscopic diagnosis apparatus, in the autofluorescence observation mode, a laser beam (excitation light) having a central wavelength of 330 nm emitted from the laser light source LD1 is irradiated on the observation region of the subject, thereby causing the observation region to be observed. Autofluorescence is emitted simultaneously from the contained tryptophan and FAD.

  Then, the turret 74 is rotated, and first the first filter unit 76 is inserted into the optical path of the reflected light, and the combined fluorescence light is received by the image sensor 58B, and the first fluorescence image is captured. Subsequently, the second filter unit 78 is inserted on the optical path, the combined light of the autofluorescence is received by the image sensor 58B, and the second autofluorescence image is captured. At this time, by adjusting the insertion time of the first filter unit 76 and the second filter unit 78, the effective exposure amounts of the first and second pixels are adjusted to be substantially the same.

  The first autofluorescence image mainly contains tryptophan and FAD autofluorescence components, and the second autofluorescence image mainly contains FAD autofluorescence components. In the autofluorescence image processing unit 70B, the autofluorescence image corresponding to the autofluorescence of tryptophan is extracted by subtracting the second autofluorescence image from the first autofluorescence image and calculating the difference between the two. The subsequent operation is the same as that in the first embodiment.

  As described above, by adjusting the insertion time of the first filter unit 76 and the second filter unit 78, in other words, the exposure time of the first and second autofluorescence, the effective exposure amount of the first and second pixels can be increased. It can be adjusted to be almost the same. Further, the present invention is not limited to this. For example, the effective exposure amount of the first and second pixels may be adjusted by increasing the drive current amount of the laser light source at the time of imaging the second autofluorescence than the first autofluorescence. Is possible.

  The exposure amount adjustment unit adjusts the effective exposure amount of the light received by the first and second pixels of the image sensor 58B through the first and second filters, respectively, when imaging the first and second autofluorescences. Anything that can be used is not limited.

The present invention is basically as described above.
Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and it is needless to say that various improvements and modifications may be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10, 80 Endoscope diagnostic apparatus 12 Light source apparatus 14 Endoscope apparatus 16 Processor apparatus 18 Display apparatus 20 Input apparatus 22 Light source control part 24 Combiner 26 Coupler 28 Endoscope insertion part 30 Operation part 32A, 32B Connector part 34 Soft part 36 bending portion 38 tip portion 40 angle knob 42A, 42B illumination window 44 observation window 45 forceps port 46A, 46B, 48A, 48B optical fiber 50A, 50B, 52A, 52B, 56 lens 54A, 54B phosphor 57 half mirror 58A, 58B Image sensor 62A, 62B Scope cable 64A, 64B A / D converter 66 Changeover switch 68 Control unit 70 Image processing unit 70A Normal light image processing unit 70B Autofluorescence image processing unit 72 Storage unit 74 Turret 76 First filter unit 78 Second Filter part LD1, LD2 laser light source

Claims (9)

A light source that emits excitation light of a predetermined wavelength that simultaneously emits a plurality of autofluorescences;
A first filter having a spectral transmission characteristic that transmits first light including the emission wavelength range of the autofluorescence of interest;
A second filter having spectral transmission characteristics that transmits second light that is within the wavelength range of the first light and does not include the emission wavelength range of the target autofluorescence;
By irradiating the observation region of the subject with the excitation light, the combined light of the first and second autofluorescences simultaneously emitted from the observation region and dispersed by the first and second filters. An image sensor that captures images to obtain first and second autofluorescence images;
An exposure amount adjustment unit that adjusts an effective exposure amount of light received by the pixels of the image sensor through the first and second filters, respectively, during imaging of the combined light;
An image processing unit that performs image processing on the first and second autofluorescence images, extracts a noticed autofluorescence image corresponding to the noticeable autofluorescence, and displays the noticed autofluorescence image on a display device; Endoscopic diagnosis device. The first and second filters are filters provided on a light receiving surface of the image sensor,
The image sensor is an image sensor that images the combined light simultaneously through the first and second filters,
The endoscope diagnosis apparatus according to claim 1, wherein the exposure amount adjustment unit adjusts the effective exposure amount by increasing the number of pixels of the second filter than the number of pixels of the first filter. . The first and second filters are filters sequentially inserted on an optical path of light received by the image sensor,
The image sensor is an image sensor that images the combined light in a surface sequential manner through the first or second filter inserted in the optical path,
The endoscope according to claim 1, wherein the exposure amount adjustment unit adjusts the effective exposure amount by extending an exposure time during imaging of the second autofluorescence than the first autofluorescence. Diagnostic device. The first and second filters are filters sequentially inserted on an optical path of light received by the image sensor,
The image sensor is an image sensor that images the combined light in a surface sequential manner through the first or second filter inserted in the optical path,
The said exposure amount adjustment part adjusts the said effective exposure amount by enlarging the drive current amount of the said light source at the time of imaging of the said 2nd autofluorescence rather than the said 1st autofluorescence. Endoscope diagnostic device.   The endoscope diagnosis apparatus according to any one of claims 1 to 4, wherein the image processing unit is configured to extract the focused autofluorescence image by calculating a difference between the first and second autofluorescence images. .   The endoscope diagnosis apparatus according to any one of claims 1 to 5, wherein the light source emits a plurality of excitation lights having different wavelengths that simultaneously emit a plurality of autofluorescences. A second light source that emits white light;
A second imaging element that captures reflected light reflected from the observation region by irradiating the observation region of the subject with the white light, and acquires a white light image;
The said image processing part produces | generates a synthesized image by synthesize | combining the said white light image and the said attention autofluorescence image, and displays this synthesized image on the said display apparatus. Endoscope diagnostic device.   8. The image processing unit assigns the focused autofluorescence image to the G channel of the composite image and the white light image to the B and R channels of the composite image, and displays the composite image in pseudo color. The endoscopic diagnostic apparatus according to 1.   The endoscopic diagnosis apparatus according to claim 1, wherein the autofluorescence of interest is autofluorescence emitted from tryptophan, FAD, or porphyrin.

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