JP2013102897A - Endoscopic diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscopic diagnostic apparatus capable of acquiring an image with an excellent diagnostic capability by measuring different fluorescence characteristics depending on an observed region of a subject and the state of lesion (the stage of progression, etc.) with measuring light in advance and by performing autogenous fluorescent observation based on optimum observation conditions.SOLUTION: The endoscopic diagnostic apparatus includes: a light source part 12 capable of emitting excitation light; imaging parts 56, 80, 74, 58 and 62 for capturing autogenous fluorescent images by imaging autogenous fluorescent light; an optical path separation/integration means 80 for separating the incoming autogenous fluorescence into a plurality of paths before imaging, or integrating the autogenous fluorescence; a plurality of rotary filters 74 set in the respective separated paths and having a plurality of spectroscopic filters 76 with different wavelength bands for transmitting light; a contrast calculation means 69 for calculating the contrast of the autogenous fluorescent image based on the autogenous fluorescent image acquired in pre-imaging; and a filter determination means 71 for determining a combination of the spectroscopic filters 76 for main imaging based on the contrast.

Description

  The present invention relates to an endoscope diagnosis apparatus that captures autofluorescence emitted from an autofluorescent substance contained in an observation region of a subject (living body) and acquires an autofluorescence image.

  Conventionally, normal light (white light) emitted from the light source device is guided to the distal end of the endoscope and irradiated on the subject's observation area, and the reflected light is imaged to obtain a normal light image (white light image). In addition, an endoscope 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 observation area of the subject, and autofluorescence emitted from the autofluorescent material is imaged to synthesize autofluorescence. An endoscope diagnostic apparatus that acquires an image (autofluorescence image, special light image) and performs autofluorescence observation (special light observation) is used.

  For example, Patent Document 1 discloses an endoscope diagnostic apparatus that performs fluorescence observation including autofluorescence observation, and can perform switching between normal light observation and fluorescence observation (special light observation). Is described.

  Further, Patent Document 2 describes an endoscope diagnostic apparatus that can perform autofluorescence observation and has a plurality of excitation light sources.

  Patent Document 3 describes an endoscope diagnostic apparatus that can perform autofluorescence observation and that can distinguish between normal tissue and abnormal tissue of a subject using autofluorescence. Furthermore, Patent Document 4 describes that, although it is not autofluorescence observation, in Raman spectroscopy, a filter is installed in accordance with the tissue that is the subject before the detector.

JP 2011-62408 A JP 2006-187598 A Japanese Patent No. 3810337 JP 2010-249835 A

However, although Patent Documents 1 and 2 describe an endoscope diagnostic apparatus capable of performing autofluorescence observation, the wavelength band of the excitation light source and the intensity ratio of the excitation light source are the subject (observation site) and It is fixed regardless of the observation conditions, and it depends on the observation site and the state of the lesion, that is, the thickness of the mucous membrane, the blood volume, and the type and amount of the autofluorescent substance. Fluorescence observation was not possible.
In Patent Document 3, autofluorescence is used to facilitate detection of abnormal tissue, but there is no description of selecting and installing an optimal light receiving filter for an observation site.
In Patent Document 4, it is described that the filter on the detector side is changed according to the observation site, but there is no description that the filter is changed depending on the state of the lesion, and Raman is used instead of autofluorescence observation. This is observation of Raman scattered light based on spectroscopy, and tissue fluorescence (autofluorescence) is removed and corrected.

  The purpose of the present invention is to perform autofluorescence observation under the optimum observation conditions corresponding to the observation site and the state of the lesion, so pre-photographing (pre-photometry) is performed in advance to measure the optimum observation conditions, and the measured optimum Another object of the present invention is to provide an endoscope diagnostic apparatus characterized by performing autofluorescence observation based on various observation conditions.

  In order to solve the above problems, the present invention provides a light source unit capable of irradiating white light and predetermined narrow band excitation light, respectively, and the biological tissue is irradiated with excitation light from the light source unit. An image capturing unit that captures auto-fluorescence emitted from the auto-fluorescent substance contained in the image to acquire an auto-fluorescence image, and light that separates and integrates auto-fluorescence incident on the image capturing unit into a plurality of paths before imaging Path separation / integration means, a plurality of rotary filters each provided with a plurality of spectral filters having different wavelength bands of transmitted light, respectively, in the middle of the plurality of paths, and autofluorescence images acquired by pre-imaging by the imaging unit The contrast calculation means for calculating the contrast of the autofluorescence image based on the above, and the above-mentioned installed in the plurality of paths for the main photographing based on the calculated contrast of the autofluorescence image Filter determining means for determining a combination of spectral filters of a plurality of rotary filters, irradiating the excitation light with a predetermined type and emission intensity of the excitation light emitted from the light source unit, and Rotating and sequentially installing a combination of the plurality of spectral filters, performing a plurality of pre-photographing by the imaging unit, obtaining a plurality of autofluorescence images having different combinations of the installed spectral filters, and the contrast The calculation means calculates the contrast of the plurality of autofluorescence images acquired in the pre-photographing, and the filter determination means calculates the contrast of the plurality of rotation filters for main photographing based on the calculated contrast of the plurality of autofluorescence images. An endoscope diagnostic apparatus for determining a combination of the spectral filters is provided.

  The optical path separation and integration unit separates the autofluorescence incident on the imaging unit into two paths including a first path and a second path having the same amount of light before imaging, and the plurality of rotation filters. Is preferably composed of a first rotary filter installed in the first path and a second rotary filter installed in the second path.

  The rotary filter preferably includes a first spectral filter whose center of the wavelength band of the transmitted light is 450 nm and a second spectral filter whose center of the wavelength band of the transmitted light is 500 nm.

The contrast calculation means calculates the contrast by creating a histogram from the pixel values of the autofluorescence image and calculating the following equation (1) from the high pixel value Lmax and the low pixel value Lmin in the histogram. It is preferable to be calculated by

The contrast calculation by the contrast calculation means is performed by creating a histogram from the pixel values of the autofluorescence image and calculating the following equation (2) from the high pixel value L _max and the low pixel value L _{min in the} histogram. It is preferable to calculate by doing.

The contrast calculation by the contrast calculation means is performed by creating a histogram from the pixel values of the autofluorescence image and calculating the following expression (3) from the high pixel value L _max and the low pixel value L _{min in the} histogram. It is preferable to calculate by doing.

The contrast calculation by the contrast calculation means is performed by creating a histogram from the pixel values of the autofluorescence image and calculating the following formula (4) from the high pixel value L _max and the low pixel value L _{min in the} histogram. It is preferable to calculate by doing.

The contrast calculation in the contrast calculation means is performed by creating a histogram from the pixel values of the autofluorescence image and calculating the following equation (5) from the high pixel value L _max and the low pixel value L _{min in the} histogram. It is preferable to calculate by doing.

The contrast calculation by the contrast calculation means is performed by creating a histogram from the pixel values of the autofluorescence image and calculating the following equation (6) from the high pixel value L _max and the low pixel value L _{min in the} histogram. It is preferable to calculate by doing.

Further, the low pixel value L _min is an average value of the low value 10% in the histogram after removing the high value 5% from the histogram, and the high pixel value L _max is the high value 5% from the histogram. It is preferable that the average value is a high value of 10% in the histogram after removal.

  The contrast calculation by the contrast calculation means is performed by creating a histogram from the pixel values of the autofluorescence image and removing an average value of 30% from the histogram after removing a high value of 10% from the histogram. It is preferable to be calculated as follows.

  Moreover, it is preferable that the autofluorescence image used for the contrast calculation in the contrast calculation unit is an autofluorescence image output at a low resolution in the imaging unit.

  Moreover, it is preferable that the autofluorescence image used for the contrast calculation in the contrast calculation means is the autofluorescence image in which only the central region of the captured image is output in the imaging unit.

  Moreover, it is preferable that the said autofluorescence image is a synthesized image produced | generated by the image process part based on the image signal of the normal light imaged in the said imaging part, and the image signal of autofluorescence.

  In addition, a first combination in which the spectral filter of the first rotary filter is the first spectral filter, and the spectral filter of the second rotary filter is the first spectral filter. The spectral filter is the first spectral filter, the spectral filter of the second rotating filter is the second spectral filter, or the spectral filter of the first rotating filter is the second spectral filter, A second combination in which the spectral filter of the second rotary filter is the first spectral filter, and the spectral filter of the first rotary filter is the second spectral filter, and the spectral of the second rotary filter Imaging is performed in each of the third combinations in which a filter is the second spectral filter, and the contrast calculation unit is provided for the first combination. A first contrast, a second contrast for the second combination, and a third contrast for the third combination, respectively, and the filter determining means is configured to calculate the first contrast and the second contrast. It is preferable that a combination of filters having the largest contrast is determined among the contrasts of the third and third contrasts, and autofluorescence observation is performed based on the determined filter combination.

  In addition, the optical path separation / integration unit includes the first path, the second path, the third path, and the fourth path, which have the same amount of light before the imaging. The plurality of rotary filters are separated into one path, and the plurality of rotary filters include a first rotary filter installed in the first path, a second rotary filter installed in the second path, and the third path. It is preferable to comprise a third rotary filter installed in the fourth path and a fourth rotary filter installed in the fourth path.

  According to the present invention, different fluorescence characteristics depending on the observation region of the subject and the state of the lesion (such as progress) are measured by prior pre-photographing (pre-photometry), and autofluorescence observation is performed based on optimal observation conditions. Therefore, it is possible to obtain a captured image with better diagnostic ability.

1 is an external view showing an embodiment of an overall configuration of an endoscope diagnostic apparatus according to the present invention. It is a block diagram which shows typically the internal structure of the endoscope diagnostic apparatus of this embodiment shown in FIG. It is a conceptual diagram showing the front-end | tip part of the endoscope insertion part of the endoscope diagnostic apparatus shown in FIG. It is the elements on larger scale of the optical path isolation | separation integration means of the endoscope apparatus which concerns on this invention. (A) is an external view of an embodiment of a rotary filter installed in the path of the optical path separating and integrating means of the endoscope apparatus according to the present invention, and (B) is an endoscope apparatus according to the present invention. It is an external view of the other Example of the rotary filter installed in FIG. It is explanatory drawing explaining an example of the contrast calculation in the contrast calculation means of the endoscope diagnostic apparatus shown in FIG. It is explanatory drawing explaining the other example of the contrast calculation in the contrast calculation means of the endoscope diagnostic apparatus shown in FIG. It is the elements on larger scale of the other Example of the optical path separation integration means of the endoscope apparatus which concerns on this invention.

  An endoscope diagnostic apparatus according to the present invention will be described in detail below based on a preferred embodiment shown in the accompanying drawings.

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

  Here, the endoscope diagnosis apparatus 10 irradiates a subject with normal light (white light), images the reflected light, and displays (observes) a normal light image (white light image) (normal light observation mode (white). A self-illumination mode) and an excitation light (special light) for self-fluorescence observation, illuminate the subject, image the self-fluorescence excited by the excitation light, and display a self-fluorescence composite image (autofluorescence image) A fluorescence observation mode (special light observation mode), and when the normal light observation mode is switched to the auto-fluorescence observation mode, a pre-determining spectral filter 76 that is optimal for auto-fluorescence observation is determined for the subject in the excitation light irradiation range. Take a photo (pre-metering). Each mode is appropriately switched based on an instruction input from the selector switch 66 (described later) of the endoscope body 14 or the input device 20.

  Although details will be described later, the endoscope diagnosis apparatus 10 of the present invention includes a plurality of spectral filters 76 used for pre-imaging as the rotation filter 74, and when switching to the auto-fluorescence observation mode, the plurality of the plurality of spectral filters 76 are used. Pre-photographing is performed by sequentially switching the spectral filter 76.

(Light source device)
The light source device 12 shown in FIG. 2 includes a light source control unit 22, two types of laser light sources LD1 (center wavelength 405 nm) and LD2 (center wavelength 445 nm) that emit laser beams having different center wavelengths, and a combiner (multiplexer). ) 24 and a coupler (demultiplexer) 26. However, in the present invention, LD2 (center wavelength 445 nm) is used as a white light source in combination with a phosphor 54 described later. Therefore, if white light can be irradiated in addition to the excitation light, the laser light source does not need to be two types, and may be one type (that is, LD2 is not necessary, and only LD1 is possible). Good). Of course, there may be more than two types. As the white light source, instead of using the excitation light source as described above, for example, a white light source such as a xenon light source may be used.

  In the present embodiment, as described above, 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 405 nm and 445 nm, respectively. The laser light source LD1 is a light source that irradiates excitation light for simultaneously emitting autofluorescence from a plurality of autofluorescent substances, for example, FAD (Flavin Adenin Dinucleotide), porphyrin (PAD), and the like included in the observation region of the subject. . The laser light source LD2 also functions as a light source for irradiating excitation light for simultaneously emitting autofluorescence from a plurality of autofluorescent materials or the like included in the observation area of the subject, as with the above-described LD1, and as will be described later. Also, it functions as a light source for generating excitation light for generating white light (pseudo white light) from the phosphor.

As an autofluorescent substance included in the observed region of the subject, for example, FAD has a wavelength 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. Exhibits autofluorescence of the range. Porphyrin emits autofluorescence of about 610 to 640 nm when irradiated with excitation light having a predetermined center wavelength included in a wavelength range of about 350 to 550 nm.
The amount of these autofluorescent substances contained in the observed area of the subject varies depending on the observation site, and also varies depending on whether the observed area is a lesion, the degree of progression of the lesion, and each individual. When the central wavelength and the irradiation intensity of the excitation light are predetermined, the contrast of the observed autofluorescence image varies depending on the transmission wavelength band of the spectral filter 76 installed in front of the image sensor 58 described later.

Moreover, although porphyrin and FAD were mentioned as an autofluorescent substance, an autofluorescent substance is not necessarily limited to these.
For example, other autofluorescent materials include NADH and collagen, which emit autofluorescence upon receiving excitation light having a wavelength range of about 250 to 400 nm and about 200 to 400 nm, respectively.

The laser light sources LD1 and LD2 are individually subjected to on / off control, light intensity control based on irradiation intensity, and irradiation time by a light source control unit 22 controlled by a control unit 70 of the processor device 16 described later.
As the light sources LD1 and LD2, broad type InGaN laser diodes can be used, and InGaNAs laser diodes, GaNAs laser diodes, and the like can also be used.

  In addition, the normal light source for generating normal light (white light) in the normal light observation mode is not limited to the combination of excitation light and phosphor as described above, and any light source that emits white light may be used. A xenon lamp, a halogen lamp, a white LED (light emitting diode), or the like can also be used. The excitation light source for generating the excitation light in the auto fluorescence observation mode (including pre-photographing) is not limited to the laser light source (semiconductor laser), and the autofluorescence substance can be excited to emit autofluorescence. Various light sources capable of emitting excitation light with sufficient intensity, for example, a combination of a white light source and a band limiting filter can be used.

  In addition, the wavelength of the excitation light in the normal light observation mode (center wavelength, narrow-band light wavelength range) is not particularly limited, and all excitation light having a wavelength capable of generating pseudo white light from the phosphor can be used. It is. The wavelength of the excitation light in the autofluorescence observation mode is not particularly limited, and all excitation lights having wavelengths that can simultaneously excite a plurality of autofluorescent substances to emit autofluorescence can be used. Light having a wavelength of 405 ± 10 nm or light having a central wavelength of 445 nm ± 10 nm can be preferably used.

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

In the normal light observation mode, the light source control unit 22 turns off the laser light source LD1, turns on the laser light source LD2, controls the combiner 24 and the coupler 26, and the narrow band light from the laser light source LD2 is phosphor 54A described later. And 54B, which will be described later, are controlled to be irradiated from optical fibers 48A and 48B.
Further, the light source control unit 22 turns on the laser light source LD1 and controls the combiner 24 and the coupler 26 in the auto fluorescence observation mode (including pre-photographing mode), and narrowband light emitted from these laser light sources LD1. Is demultiplexed and controlled to be irradiated from optical fibers 46A and 46B described later.
In the case of pre-photographing, a plurality of spectral filters 76 including a combination thereof are prepared in advance in an optical path separation / integration unit 80 (described later) installed in front of an image sensor 58 (described later). The unit 22 installs a plurality of spectral filters 76 in a predetermined combination, and sequentially performs pre-photographing (autofluorescence imaging). The image data of the autofluorescence obtained by the pre-photographing is combined with the normal light image captured in the normal light observation mode in the image processing unit 68 to be described later to be an autofluorescence image. The contrast of the fluorescence image (composite image with the normal light image) is calculated.
Based on the calculated contrast, a filter determination unit 71 (to be described later) of the control unit 70 determines a filter combination that is optimal for autofluorescence observation. The light source control unit 22 determines the combination of spectral filters 76 that has been determined. Autofluorescence photography is performed.

  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. Further, the combiner 24 and the coupler 26 are controlled by the light source controller 22, and the laser light emitted from each of the laser light sources LD1 and LD2 is controlled to be emitted from a desired optical fiber. However, the present invention is not limited thereto, 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.

(Endoscope body)
Subsequently, as shown in FIG. 2, the endoscope main body 14 has four systems (four lights) of light (normal light or for autofluorescence observation) from the distal end of the endoscope insertion portion 28 inserted into the subject. An electronic endoscope having an illumination optical system (including excitation light (including pre-photographing)) and one system (one eye) of an imaging optical system that captures an endoscopic image of an observation region . The endoscope main body 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 main body 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 rotation 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 depending on a portion of the subject in which the endoscope main body 14 is used, and the endoscope distal end portion 38 can be directed to a desired observation portion. it can.

  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 behind 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 blue laser light (for example, center wavelength 445 ± 10 nm) from the laser light source LD2 and excite and emit green to yellow light (for example, YAG-based fluorescent material). Or a fluorescent material such as BAM (BaMgAl ₁₀ O ₁₇ ). When excitation light for normal light observation is irradiated onto the phosphors 54A and 54B, green to yellow excitation emission 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 light from the illumination windows 42A and 42B simultaneously. Different illumination lights can be irradiated from the illumination windows 42A and 42B. An equivalent function can be realized even in an illumination optical system that emits four systems of illumination light.

On the other hand, an optical system such as a lens 56 is attached to the back of the observation window 44, and an optical path separation and integration unit 80 is provided to the back of the lens 56.
As shown in detail in FIG. 4, the optical path separation / integration unit 80 includes half mirrors 82A and 82B and mirrors 84A and 84B, and includes a first path including the half mirror 82A, the mirror 84A, and the half mirror 82B. The first rotary filter 74A and the second rotary filter 74B are respectively installed between the second path including the half mirror 82A, the mirror 84B, and the half mirror 82B. Preferably, the first rotary filter 74A is installed between the half mirror 82A and the mirror 84A, and the second rotary filter 74B is installed between the half mirror 82A and the mirror 84B.

The light passing through the lens 56 is separated into two paths by the same amount by the half mirror 82A, and is again integrated by the half mirror 82B through the first path and the second path.
The integrated light is a CCD (Carge1 Coupled Device) image sensor, a CMOS (Charge Metal-Oxide Semiconductor) image sensor, or the like that is installed behind the optical path separation and integration unit 80 and acquires image information of the observation region. An image is picked up by the image pickup device 58.
Since the image sensor 58 is used for each frame by dividing time, it is used for both normal light observation and autofluorescence observation (including pre-photographing).
In the present invention, the imaging unit includes an observation window 44, a lens 56, an optical path separation and integration unit 80, a rotation filter (spectral filter 76) 74, an imaging element 58, a scope cable 62 described later, and an A / D converter 64 described later. , And an image processing unit 68 described later.

  Further, as shown in FIG. 5A, the first rotary filter 74A and the second rotary filter 74B are installed in the normal light observation mode, and a transmission unit 78 that directly passes the reflected light from the subject tissue. The first spectroscopic filter 76A and the second spectroscopic filter 76B are provided in the auto-fluorescence observation mode (including pre-photographing), and cut off the excitation light that is reflected light from the subject tissue. The first rotary filter 74A and the second rotary filter 74B are configured to transmit the transmission unit 78, the first spectral filter 76A, and the second spectral filter according to an imaging mode switching instruction from the input device 20 or the selector switch 66 described later. 76B is used while being switched, and the combination of spectral filters is changed between the first rotary filter 74A and the second rotary filter 74B. In the autofluorescence observation mode, when the normal light observation and the autofluorescence observation are alternately performed, the autofluorescence observation mode is rotated by a rotating unit (not shown) in accordance with the period of the normal light observation and the autofluorescence observation.

For example, when the large intestine is selected as the part of the living body for autofluorescence observation, the first spectral filter 76A of the first rotary filter 74A and the second rotary filter 74B is, for example, a predetermined wavelength band centered on 450 nm ( For example, a spectral interference filter that transmits light having a center wavelength of ± 20 nm may be selected, and the second spectral filter 76B may have a predetermined wavelength band (for example, a center wavelength) centered on, for example, 500 nm. A spectral interference filter that transmits light in a wavelength band of ± 20 nm may be selected. A specific example of the first spectral filter 76A is a bandpass filter 3RD430LP-470SP manufactured by Omega Optical, and a specific example of the spectral filter 76B is a bandpass filter 3RD480LP-520SP of the same company. It is done.
Of course, the transmission wavelength bands of the first spectral filter 76A and the second spectral filter 76B are not limited to those described above. For example, the transmission wavelength band may be narrower or wider, and the transmission wavelength band may be closer to the longer wavelength side. Specifically, a spectral filter (Omega Optical: 3RD450LP-600SP) having a transmission wavelength band of 450 nm to 600 nm, a spectral filter (Omega Optical: 3RD610LP-640SP) having a transmission wavelength band of 610 nm to 640 nm, and the like are conceivable.
Further, in this embodiment, the part of the living body that is the target of autofluorescence observation is not limited to the large intestine, but may be any part such as the esophagus or stomach. It may be changed. A clearer autofluorescence image can be acquired by changing the spectral characteristics of the spectral filter to an appropriate one according to a predetermined part.

As described above, in the normal light observation mode, the optical path separation / integration unit 80 includes the transmission unit 78 of the first rotary filter 74A and the second rotary filter 74B in the first path and the second path described above. Are installed, and return light from the subject including the autofluorescence is directly passed to the image sensor 58.
In the case of the above-described pre-photographing, the first combination in which the first spectral filter 76A is installed in each of the first rotary filter 74A in the first path and the second rotary filter 74B in the second path. The first spectral filter 76A is installed in the first rotary filter 74A, and the second spectral filter 76B is installed in the second rotary filter 74B (or the second spectral filter in the first rotary filter 74A). 76B and the second spectral filter 76A is installed in the second rotary filter 74B) and the second spectral filter in each of the first rotary filter 74A and the second rotary filter 74B. Shooting is performed by sequentially switching the three combinations of the third combination in which the filter 76B is installed.
Then, in the autofluorescence observation mode after the end of pre-photographing, among the above three combinations, the filter combination that is most suitable for photographing is set in the filter determination means 71 described later.
The optical path separation / integration unit 80 is not limited to the above-described configuration, and the rotation filter 74 can be installed in the path after the separation by switching the plurality of spectral filters 76 and the transmission unit, respectively. It is not limited to the configuration.

  The imaging element 58 receives normal light (reflected light) and autofluorescence on a light receiving surface (imaging surface), photoelectrically converts the received light, and outputs an imaging signal (analog signal). A plurality of sets of pixels are arranged on a matrix, with a set of three colors of G and B pixels. On the light receiving surface of the image sensor 58, the reflected light in the wavelength range of 370 to 720 nm of the visible light from the observation region is divided into three wavelength regions corresponding to the R pixel, G pixel, and B pixel, respectively. R, G, and B color filters (not shown) having spectral transmission characteristics that transmit light are provided.

Further, at the time of pre-photographing in the autofluorescence observation mode, the image sensor 58 may perform binning processing to reduce the number of pixels and output the image data of the autofluorescence image. You may output only the imaging data of the autofluorescence image acquired in the part.
The pre-photographing is intended only for the purpose of determining the combination of the spectral filters 76 of the plurality of rotary filters 74, not for obtaining an autofluorescence image or the like. This is because if the capacity is reduced, the contrast calculation unit 69 of the image processing unit 68 (to be described later) can quickly calculate the contrast.

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

  The 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 area of the subject. Then, the reflected light from the observation region irradiated with light or the autofluorescence emitted from the autofluorescent material in the observation region passes through the lens 56 and passes through the optical path separation and integration means 80 (in the middle of the first rotation). An image is formed on the light receiving surface of the image sensor 58 through a filter 74A and a second rotary filter 74B), and is imaged by photoelectric conversion by the image sensor 58. The imaging element 58 outputs an imaging signal (analog signal) of the observed area of the imaged subject.

  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 applied to the phosphors 54A and 54B, and white light emitted from the phosphors 54A and 54B. Light is emitted from the illumination windows 42A and 42B to the observation area of the subject. Then, the reflected light from the observation area of the subject irradiated with white light is collected by the lens 56 and enters the optical path separation / integration means 80 to be separated into the first path and the second path, and the first path Are integrated through the transmission part 78 of the first rotation filter 74A of the second path and the transmission part 78 of the second rotation filter 74B of the second path. The light is dispersed by a color filter (not shown) on the surface, and normal light is imaged by the image sensor 58.

  On the other hand, in the autofluorescence observation mode (including pre-photographing), the excitation light for autofluorescence observation emitted from the laser light source LD1 (center wavelength 405 nm) is guided by the optical fibers 46A and 46B, and the distal end of the endoscope The light is emitted from the portion 38 toward the observation area of the subject. Then, the combined light of autofluorescence emitted simultaneously from a plurality of autofluorescent substances included in the observation region of the subject irradiated with the excitation light is collected by the lens 56 and enters the optical path separation / integration unit 80, and the first The first and second spectral filters 76A and 76B of the first rotary filter 74A in the first path and the second rotary filter in the second path are separated into a path and a second path. The light having a predetermined wavelength band including the component of the excitation light (405 ± 10 nm) is passed through each of the first spectral filter 76A and the second spectral filter 76B of 74B, and each of the spectral filters 76 described above. The light is cut, the respective lights are integrated, exit the light path separation and integration means 80, and the autofluorescence is imaged by the image sensor 58 installed behind the light path separation and integration means 80.

At the time of pre-photographing, autofluorescence is sequentially captured as described above based on the combination of all the spectral filters stored in advance in the storage unit 72, and the autofluorescence image is captured by the contrast calculation means 69 of the image processing unit 68 described later. Based on the calculated contrast, a filter determining unit 71 (to be described later) of the control unit 70 determines a filter (including a combination of filters) that is optimal for autofluorescence observation of the target region of the subject.
Then, after the pre-photographing is completed, the optimum autofluorescence observation is performed based on the determined optimum filter (spectral filter) combination.

  The excitation light for autofluorescence observation in the present embodiment is laser light (LD1) having a center wavelength of 405 ± 10 nm as described above, and the autofluorescence passes through the spectral filter 76, for example, in a wavelength range of about 460 to 640 nm. The combined light is received and imaged. Therefore, the autofluorescence image mainly contains autofluorescence components of FAD and porphyrin.

  In addition, an image signal (analog signal) of an image (normal light image, autofluorescence image) output from the image sensor 58 is input to the A / D converter 64 through the scope cable 62. The A / D converter 64 converts an image signal (analog signal) from the image sensor 58 into an image signal (digital signal). The converted image signal is input to the image processing unit 68 of the processor device 16 via the connector unit 32B.

(Processor unit)
Subsequently, the processor device 16 includes an image processing unit 68, a control unit 70, and a storage unit 72. The image processing unit 68 includes a contrast calculation unit 69, and the control unit 70 includes a filter determination unit 71. The control unit 70 is connected to the display device 18, the input device 20, and rotation means (not shown) of the first rotation filter 74 </ b> A and the second rotation filter 74 </ b> B of the optical path separation and integration means 80. As described above, not only switching of the imaging mode (normal light observation mode and autofluorescence observation mode) but also setting of specific filters (filter combinations) can be performed via the input device 20.
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 of the endoscope body 14 or the input device 20, and also controls the rotation filter 74 to control a predetermined spectral filter. 76 is installed, the image signal input from the endoscope body 14 is subjected to image processing, a display image is generated, stored in the storage unit 72, and output to the display device 18.

In both the normal light observation mode and the autofluorescence observation mode, the image processing unit 68 performs the A / D converter 64 of the endoscope main body 14 according to the image type of the normal light image and the autofluorescence image. The image signal (image data) supplied from is subjected to predetermined image processing suitable for each of the normal light image and the autofluorescence image, and the normal light image signal (normal light image) and the autofluorescence image signal (autofluorescence) Image).
The autofluorescence image signal (autofluorescence image) is a composite image generated by synthesizing the above-described normal light image signal and autofluorescence image signal supplied from the endoscope body by the image processing unit 68. It is a signal (composite image).

  The image signal processed by the image processing unit 68 is sent to the control unit 70. In the control unit 70, the normal light image or 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 70, 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.

  Further, the image processing unit 68 includes a contrast calculating unit 69. When the endoscope diagnosis apparatus 10 is switched to the autofluorescence observation mode and performs pre-imaging, the image processor 68 is based on the autofluorescence image signal acquired by pre-imaging. Then, the contrast of the autofluorescence image is calculated.

すると、自家蛍光画像のコントラストが求められる。 As shown in FIG. 5, the contrast calculation unit 69 calculates the contrast by creating a histogram corresponding to the pixel value and the number of pixels from the autofluorescence image signal (autofluorescence image data). 5% is cut off, and from the remaining image data (histogram in the dotted frame in FIG. 5), the average value of the upper 10% pixel values (average value of luminance values) L _max and the average value of the lower 10% pixel values (Average value of luminance values) L _min is calculated.
After calculating L _max and L _min , Micson contrast formula (1) is calculated based on these values.

Then, the contrast of an autofluorescence image is calculated | required.

  The contrast of the image signal processed by the image processing unit 68 and the autofluorescence image calculated by the contrast calculating unit 69 is stored in the storage unit 72 through the control unit 70 together with the combination of filters at the time of capturing the autofluorescence image.

As shown in FIG. 6, the contrast calculation unit 69 calculates the contrast by creating a histogram corresponding to the pixel value and the number of pixels from the autofluorescence image data as shown in FIG. The average of the upper 30% pixel values may be taken from the image data (histogram in the dotted frame in FIG. 6) to obtain the contrast of the autofluorescence image.
As described above, the calculated contrast of the autofluorescence image is stored in the storage unit 72 through the control unit 70 together with the combination of the autofluorescence image data and the filter at the time of capturing the autofluorescence image.

としてもよく、また、（１）式の各Ｌに対して対数（常用対数、自然対数どちらでも可）をとって、

としてもよく、また、同様に、（２）式の各Ｌに対して対数（常用対数、自然対数どちらでも可）をとって、

としてもよい。 Note that the contrast calculation in the contrast calculation means 69 is performed by taking a simple difference between L _max and L _{min in} addition to the above-described equation (1).

Also, taking a logarithm (either common logarithm or natural logarithm is acceptable) for each L in the equation (1),

Similarly, taking a logarithm (either common logarithm or natural logarithm is acceptable) for each L in equation (2),

It is good.

としてもよい。
上述の他にも、Ｌ_ｍａｘとＬ_ｍｉｎとの単純な比率（Ｌ_ｍａｘ／Ｌ_ｍｉｎ）を

としてもよく、また、Ｌ_ｍａｘを、そのまま用いて、

としてもよい。
また、前述の画素値と画素の数に対応するヒストグラムの全面積、つまり、自家蛍光画像の全画素数と、自家蛍光画像の全画素値の積算値とを用いて、画素値の平均値を算出し、その平均値を自家蛍光画像のコントラストとしてもよい。 Further, each L in the equation (1) is set to a power of x (x is an arbitrary number),

It is good.
In addition to the above, a simple ratio (L _max / L _min ) between L _max and L _min

It is also possible to use L _max as it is,

It is good.
Further, using the total area of the histogram corresponding to the above-described pixel value and the number of pixels, that is, the total number of pixels of the autofluorescence image and the integrated value of all the pixel values of the autofluorescence image, the average value of the pixel values is calculated. The average value may be calculated as the contrast of the autofluorescence image.

In addition, the autofluorescence image used for the above-described contrast calculation is subjected to processing such as binning (or, if there is a low-resolution image sensor in addition to a high-resolution image sensor, A captured low-resolution autofluorescence image may be used, or an autofluorescence image obtained by extracting only the central region of the captured autofluorescence image may be used. Since the number of pixels used to calculate contrast is reduced, processing can be performed quickly.
The contrast calculation method in the contrast calculation unit 69 can be switched through the input device 20.

  The contrast calculation based on the autofluorescence image data is performed based on the captured autofluorescence image, that is, the number of combinations of filters stored in advance, and is stored in the storage unit 72 together with the autofluorescence image data. .

The control unit 70 is based on an instruction from the changeover switch 66 of the endoscope body 14 or the input device 20, for example, an instruction such as an observation mode (normal light observation mode and autofluorescence observation mode (including pre-imaging)). The operation of the image processing unit 68 and the light source control unit 22 of the light source device 12 is controlled, and the first rotation filter 74A and the second rotation filter 74B (not shown) of the optical path separation / integration unit 80 described above. To set the first rotary filter 74A and the second rotary filter 74B (set any one of the transmission part 78, the first spectral filter 76A, and the second spectral filter 76B).
In addition, the control unit 70 stores the display image that has been subjected to image processing by the image processing unit 68 and can be displayed in the storage unit 72, and displays the display image on the display device 18 as required by an instruction from the input device 20 or the like. .

Then, the control unit 70 performs pre-photographing (automatic fluorescence image capturing) based on a combination of a plurality of filters stored in advance in the storage unit 72 at the time of pre-photographing, and the image processing unit 68 and the contrast calculating unit 69. The self-fluorescent image corresponding to the set combination of filters calculated in step S1 and the contrast thereof are stored in the storage unit 72, and the filter determination unit 71 determines the combination of filters with the highest contrast.
The control unit 70 controls the rotation means (not shown) of the first rotation filter 74A and the second rotation filter 74B based on the determined combination of filters, so that the optimum filter for observing the observation area of the subject can be obtained. Autofluorescence observation can be performed in combination.
The above is the configuration of the endoscope diagnostic apparatus 10 of the present invention.

  Next, the operation of the endoscope diagnosis apparatus 10 of the present invention will be described for each observation mode.

(Normal light observation mode)
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 ± 10 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 applied to the subject, and the reflected light enters the light path separation / integration means 80 through the lens 56 and is separated, and the separated light passes through the first path. The transmission unit 78 of the first rotation filter 74A and the transmission unit 78 of the second rotation filter 74B of the second path are respectively integrated again, exit the optical path separation and integration unit 80, and then the image sensor 58 The normal light image including the image signals of the R, G, and B channels is acquired by receiving the light. The normal light image is displayed in color based on the R, G, and B channel image signals.

(Autofluorescence observation mode)
In the case of pre-photographing in the autofluorescence observation mode, for example, if three combinations of filters are stored in the storage unit 72 in advance, and pre-photographing is performed based on the three combinations of filters (for example, the first combination) : 450 nm (emission intensity of excitation light 1.0), second combination: 450 nm (0.5) +500 nm (0.5), and third combination: 500 nm (1.0)), number of filter combinations The light emission, irradiation intensity and irradiation time of the laser light source LD1 are controlled through the light source control unit 22 in units of three frames, and the rotation means (not shown) of the first rotation filter 74A and the second rotation filter 74B are controlled. Then, imaging is performed in the order of the first combination, the second combination, and the third combination.

  In the above-described example, in the pre-shooting, all filter combinations from the first combination to the third combination are picked up at a time. For example, normal light observation and pre-shooting are alternately performed for each frame. Switch, first frame: normal light observation, second frame: imaging with the first combination, third frame: normal light observation, fourth frame: imaging with the second combination, fifth frame: normal light observation , Sixth frame: imaging in the third combination may be performed in this order.

Then, in the image processing unit 68, the normal light image signal (normal light image data) stored in the storage unit 72 and the FAD or porphyrin autofluorescence image signal (image data) are combined, and a combined image ( That is, the autofluorescence image is displayed on the display device 18.
For example, here, by assigning the auto-fluorescent image signal to the G channel of the composite image and the R and B channels of the normal light image to the R channel and B channel of the composite image, respectively, the composite image is simulated. Displayed in color.

  It should be noted that when displaying a composite image (autofluorescent image) in pseudo color, it is arbitrary which image signal of which image is assigned to which color channel of the composite image. Further, it is not essential to display the synthesized image in pseudo color.

  As described above, the image processing unit 68 performs image processing on the autofluorescence image corresponding to the combination of filters, calculates the contrast of the autofluorescence image in the contrast calculation unit 69, and passes the first fluorescence through the control unit 72. From the combination, the autofluorescence image corresponding to the third combination and the contrast thereof are stored in the storage unit 72.

When the contrasts of the autofluorescence images corresponding to the first combination to the third combination are stored in the storage unit 72, the control unit 70 obtains the contrasts from the storage unit 72, and the filter determination unit 71 The filter combination with the highest contrast is determined as the optimum filter combination for autofluorescence observation.
In the case of Table 1 below, since the third combination has the highest contrast, the third combination is determined as the optimum filter combination for autofluorescence observation.

  The control unit 70 sets the determined filter combination (third combination in the example of Table 1), controls the irradiation intensity and irradiation time of the laser light source LD1 through the light source control unit 22, and performs autofluorescence observation. .

  In the autofluorescence observation after the pre-photographing is performed, for example, imaging is repeatedly performed in units of two 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.

  First, in the normal light observation mode of the first frame, as described above, the subject is irradiated with white light, and a normal light image including R, G, and B channel image signals is captured. Then, the normal light image signal is stored in the storage unit 72 under the control of the control unit 70.

  Subsequently, in the auto-fluorescence observation mode of the second frame, the combination of filters having the highest contrast (for example, the third combination in Table 1) at the time of pre-imaging is set by the control of the light source control unit 22, and the laser light source The light emission, irradiation intensity, and irradiation time of the LD 1 are controlled. By irradiating the observation area of the subject with the laser light (excitation light) emitted from the laser light source LD1, autofluorescence is simultaneously emitted from the FAD and porphyrin included in the observation area. Then, the combined light of both autofluorescences is received by the image sensor 58 and the autofluorescence is imaged.

  Autofluorescence imaging data (analog data) is converted into image data (digital data) by an A / D converter 58, input to an image processing unit 68, image processed by an image processing unit 68, and a normal light image. And converted into a display image, and output to the display device 18 and the storage unit 72 through the control unit 70. Since the image is captured with the optimal combination of filters determined based on the pre-photographing, the autofluorescence image displayed on the display device 18 is an autofluorescence image that has high contrast and is easy to observe.

  As mentioned above, although the endoscope diagnostic apparatus 10 of this invention was demonstrated in detail, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, various improvement and change are performed. May be.

  For example, the optical path separation / integration unit 180 of the present invention is separated into four paths of a first path to a fourth path as shown in FIG. 8, for example, and the rotary filters 174A to 174D are provided in each path. Each may be installed.

  8 includes six half mirrors 182A to 182F, two mirrors 184A and 184B, and four rotary filters 174A to 174D. The half mirrors 182A, 182B, the mirror 184A, A first path through half mirrors 184D, 184F, a second path through half mirrors 182A, 182B, 184E, 184F, a third path through half mirrors 182A, 182C, 184D, 184F, and half mirror 182A, There are four paths of a fourth path passing through 182C, mirror 184B, and half mirrors 184E and 184F.

Further, the rotary filters 174A to 174D may be the rotary filters shown in FIG. 5A and are controlled by a rotating means (not shown), and are preferably arranged at an equal distance behind the half mirrors 182B and 182C.
The optical path separation and integration unit 180 can set a finer filter combination by dividing the light path into four.
In addition, there is no restriction | limiting in particular in isolation | separation and integration of a light path, and there is no restriction | limiting in particular also about the installed spectral filter.

Moreover, the spectral filters installed in the present invention may be, for example, filters in which the transmission wavelength bandwidths of the respective spectral filters are different. For example, as shown in FIG. 5B, a band-pass filter, which has a transmission wavelength band as narrow as 420 to 450 nm, a first filter 276A, a transmission wavelength band as 430 to 490 nm, a second filter 276B, A rotary filter 274 including a third filter 276 </ b> C having a wide wavelength band of 450 to 600 nm and a transmission unit 278 may be used. In addition to these spectral filters, a spectral filter whose transmission wavelength band itself is narrow and whose wavelength band itself is closer to the longer wavelength side (for example, a transmission wavelength band of 610 nm to 640 nm, etc.) is used. May be.
Similarly to the above, when each of the first filter 276A to the third filter 276B is installed, pre-shooting is performed, the contrast of the autofluorescence image is calculated, and the filter that can capture the autofluorescence image with the highest contrast is obtained. It is set as a filter for autofluorescence observation.
By changing the spectral filter on the imaging side to change the transmission wavelength band or the bandwidth itself, it is possible to capture autofluorescence images with different contrasts, ideal for autofluorescence observation corresponding to a predetermined subject A simple spectral filter can be set.

DESCRIPTION OF SYMBOLS 10 Endoscope diagnostic apparatus 12 Light source apparatus 14 Endoscope main body 16 Processor apparatus 18 Display apparatus 20 Input apparatus 22 Light source control part 24 Combiner (multiplexer)
26 Coupler
28 Endoscope insertion part 30 Operation part 32A, 32B Connector part 34 Soft part 36 Bending part 38 End part (Endoscope end part)
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 58 Image sensor 62 Scope cable 64 A / D converter 66 changeover switch 68 image processing unit 69 contrast calculation unit 70 control unit 71 filter determination unit 72 storage unit 74 rotating filter 74A first rotating filter 74B second rotating filter 76 spectral filter 76A first spectral filter 76B second spectral Filter 78 Transmitter 80 Optical path separation and integration means 82A, 82B Half mirror 84A, 84B Mirror LD1, LD2 Laser light source

Claims (16)

A light source unit capable of irradiating white light and a predetermined narrow-band excitation light, and
An imaging unit that captures autofluorescence emitted from an autofluorescent material contained in the living tissue by irradiating the living tissue with excitation light from the light source unit, and acquires an autofluorescence image;
Auto-fluorescence incident on the imaging unit is separated into a plurality of paths before imaging, and optical path separation and integration means for integrating,
A plurality of rotary filters each having a plurality of spectral filters installed in the middle of the plurality of paths and having different wavelength bands of transmitted light;
Contrast calculation means for calculating the contrast of the autofluorescence image based on the autofluorescence image acquired by pre-shooting by the imaging unit;
Filter determining means for determining a combination of spectral filters of the plurality of rotary filters installed in the plurality of paths for the main imaging based on the calculated contrast of the autofluorescence image;
The type of excitation light emitted from the light source unit and the emission intensity thereof are set as predetermined, the excitation light is irradiated, the plurality of rotation filters are rotated, the combination of the plurality of spectral filters is sequentially installed, and the imaging unit A plurality of pre-photographing is performed to obtain a plurality of autofluorescence images with different combinations of the installed spectral filters, and the contrast calculation means calculates the contrast of the plurality of autofluorescence images obtained by pre-photographing. An endoscope diagnosis apparatus for determining a combination of the spectral filters of the plurality of rotation filters for main photographing based on the calculated contrasts of the plurality of autofluorescence images by the filter determining means. The light path separation and integration means separates the autofluorescence incident on the imaging unit into two paths consisting of a first path and a second path having the same amount of light before imaging,
2. The plurality of rotary filters include a first rotary filter installed in the first path and a second rotary filter installed in the second path. Endoscope diagnostic device. The rotary filter includes a first spectral filter whose center of a wavelength band of light to be transmitted is 450 nm;
The endoscope diagnostic apparatus according to claim 1, further comprising: a second spectral filter having a center of a wavelength band of transmitted light of 500 nm. The calculation of the contrast in the contrast calculation means is to create a histogram from the pixel values of the autofluorescence image and calculate the following equation (1) from the high pixel value L _max and the low pixel value L _{min in the} histogram. The endoscope diagnosis apparatus according to claim 1, wherein the endoscope diagnosis apparatus is calculated by:

The calculation of the contrast in the contrast calculation means is to create a histogram from the pixel values of the autofluorescence image and calculate the following equation (2) from the high pixel value L _max and the low pixel value L _{min in the} histogram. The endoscope diagnosis apparatus according to claim 1, wherein the endoscope diagnosis apparatus is calculated by:

The calculation of the contrast in the contrast calculation means is to create a histogram from the pixel values of the autofluorescence image and calculate the following expression (3) from the high pixel value L _max and the low pixel value L _{min in the} histogram. The endoscope diagnosis apparatus according to claim 1, wherein the endoscope diagnosis apparatus is calculated by:

The calculation of the contrast in the contrast calculation means is to create a histogram from the pixel values of the autofluorescence image and calculate the following equation (4) from the high pixel value L _max and the low pixel value L _{min in the} histogram. The endoscope diagnosis apparatus according to claim 1, wherein the endoscope diagnosis apparatus is calculated by:

The calculation of the contrast in the contrast calculation means is to create a histogram from the pixel values of the autofluorescence image and calculate the following equation (5) from the high pixel value L _max and the low pixel value L _{min in the} histogram. The endoscope diagnosis apparatus according to claim 1, wherein the endoscope diagnosis apparatus is calculated by:

The calculation of the contrast in the contrast calculation means is to create a histogram from the pixel values of the autofluorescence image and calculate the following equation (6) from the high pixel value L _max and the low pixel value L _{min in the} histogram. The endoscope diagnosis apparatus according to claim 1, wherein the endoscope diagnosis apparatus is calculated by:

The low pixel value L _min is an average value of the low value 10% in the histogram after removing the high value 5% from the histogram, and the high pixel value L _max is the high value 5% excluded from the histogram. The endoscope diagnosis apparatus according to any one of claims 4 to 9, wherein an average value of a high value of 10% in a later histogram is used.   The calculation of the contrast in the contrast calculation means creates a histogram from the pixel values of the autofluorescence image, and uses the average value of 30% of the high value of the histogram after removing the high value of 10% from the histogram as the contrast. The endoscope diagnosis apparatus according to claim 1, wherein the endoscope diagnosis apparatus is calculated as described above.   12. The endoscopy according to claim 1, wherein the autofluorescence image used for calculating the contrast in the contrast calculation means is an autofluorescence image output at a low resolution in the imaging unit. Mirror diagnostic device.   The autofluorescence image used for calculating the contrast in the contrast calculation means is the autofluorescence image in which only the central region of the captured image is output in the imaging unit. The endoscope diagnosis apparatus according to any one of the above.   The self-fluorescent image is a composite image generated by an image processing unit based on an image signal of normal light and an image signal of auto-fluorescence captured by the imaging unit. The endoscopic diagnostic apparatus according to any one of the above. A first combination in which the spectral filter of the first rotary filter is the first spectral filter and the spectral filter of the second rotary filter is the first spectral filter;
The spectral filter of the first rotary filter is the first spectral filter, the spectral filter of the second rotary filter is the second spectral filter, or the spectral filter of the first rotary filter is the The second spectral filter, the second combination of the second rotating filter as the first spectral filter, and the second rotating filter as the second spectral filter, Imaging is performed in each of the third combinations in which the spectral filter of the second rotation filter is the second spectral filter,
The contrast calculating means calculates a first contrast for the first combination, a second contrast for the second combination, and a third contrast for the third combination;
The filter determining means determines a combination of filters having the highest contrast among the first contrast, the second contrast, and the third contrast, and autofluorescence observation is performed based on the determined filter combination. The endoscope diagnosis apparatus according to claim 3, wherein the endoscope diagnosis apparatus is performed. The optical path separation / integration unit is configured to provide four paths including a first path, a second path, a third path, and a fourth path, in which the autofluorescence incident on the imaging unit has the same amount of light before imaging. Separated into
The plurality of rotary filters include a first rotary filter installed in the first path, a second rotary filter installed in the second path, and a third installed in the third path. The endoscope diagnosis apparatus according to claim 1, comprising: a rotation filter of the first rotation filter, and a fourth rotation filter installed in the fourth path.

Images