JP2006175052A - Fluorescent image capturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To output a fluorescent correction image which accurately reflects tissue properties of a measurement site by reducing the influence of the distortion of a fluorescence spectrum due to the dispersion or the like. <P>SOLUTION: The excitation light L22 is applied to the measurement site 50 of a subject wherein a fluorescent diagnostic medicine is injected beforehand and the fluorescence L32 emitted from the fluorescent diagnostic medicine is captured by a CCD image pickup device 107 to acquire a fluorescent image. Also, an image having a same band of the fluorescence L32 is captured as a same-band reflection image of a fluorescence wavelength out of the reflection light L7 from the measurement site 50 irradiated with the illumination light Lw and the fluorescent correction image is generated from a divisional value of the fluorescent image and the same-band reflection image of the fluorescence wavelength. The image of the tissue properties is generated by allocating a hue H on the basis of a pixel value (the divisional value) of the fluorescent correction image and a composite image based on the above image is displayed on a monitor 162. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fluorescence image capturing apparatus that measures fluorescence generated from a measurement target such as a living tissue by irradiation of excitation light and outputs an image representing information on the measurement target.

  Conventionally, the fluorescence (autofluorescence) emitted from the measured part when the living body measured part is irradiated with the excitation light of the predetermined wavelength band is utilized using the fact that the intensity and spectrum shape are different between the normal tissue and the diseased tissue. There has been proposed a technique for displaying the localization / infiltration range of a diseased tissue as a fluorescence calculation image by irradiating a living body measurement portion with excitation light of a predetermined wavelength and receiving autofluorescence emitted from the living body measurement portion.

  Normally, when the living body is irradiated with excitation light, as shown in FIG. 8, strong fluorescence is emitted from normal tissue and weak fluorescence is emitted from lesion tissue. Can be judged. In addition, using a fluorescent contrast agent that accumulates in the tumor when injected into a living body, the fluorescence emitted from the fluorescent contrast agent is measured by irradiating excitation light of a predetermined wavelength, so that the position and size of the tumor part can be determined. There is also known a fluorescence image capturing apparatus that performs imaging using fluorescence of a drug to be displayed.

  This type of fluorescence imaging apparatus basically includes an excitation light irradiating means for irradiating a living body measurement portion with excitation light, and a fluorescence image acquiring means for acquiring a fluorescence image from fluorescence emitted from a living tissue or a fluorescent contrast agent. The fluorescence calculation image generation means for generating a fluorescence calculation image in response to the output of the fluorescence image acquisition means and the display means for displaying the fluorescence calculation image are often inserted into the body cavity. It is configured to be incorporated into an endoscope, a colposcope, a surgical microscope, or the like.

  Conventionally, with respect to these fluorescence image capturing devices, various methods for generating fluorescence calculation images have been proposed in order for an observer to acquire information on tissue properties more accurately based on fluorescence from a living body measurement unit. Yes.

  Usually, when displaying the intensity of fluorescence by excitation light as an image, because the living tissue has irregularities, the intensity of excitation light irradiated to the living tissue is not uniform, and the fluorescence intensity emitted from normal living tissue is Although substantially proportional to the excitation light illuminance, the excitation light illuminance decreases in inverse proportion to the square of the distance. For this reason, especially when measuring autofluorescence, there is a case where strong fluorescence is received from a lesion tissue that is closer than a normal tissue far from the light source. The tissue properties of living tissue cannot be accurately identified.

  In order to reduce such inconveniences, the inventors obtain a ratio of two types of fluorescence intensities obtained from different wavelength bands (a narrow band near 480 nm and a wide band near 430 nm to 730 nm) by division, and the division A method for displaying a fluorescence calculation image based on a value, that is, a method for generating a fluorescence calculation image based on a difference in the shape of a fluorescence spectrum reflecting the tissue properties of a living body, or a method for receiving uniform absorption for various living tissues. Illuminating the living tissue as a reference light with illumination light including infrared light, detecting the intensity of the reflected light reflected by the biological tissue that has been irradiated with this reference light, and determining the ratio with the fluorescence intensity by dividing, A method for generating a fluorescence calculation image based on the division value, that is, a method for generating a fluorescence calculation image by obtaining a value reflecting the fluorescence yield has been proposed.

  In addition, color information is assigned to a division value of fluorescence intensity in different wavelength bands or a division value of reflected light intensity by irradiation of fluorescence intensity and reference light, and a lesion state of a living tissue is displayed as an image by the difference in color. Furthermore, by synthesizing the color image indicating the lesion state of the biological tissue due to the difference in color and the luminance image obtained by assigning luminance information to the intensity of the reflected light by irradiation of the reference light, A method of generating a fluorescence calculation image with a sense of unevenness in which the shape is reflected in the image has also been proposed (see Patent Document 1).

  In addition, when generating a fluorescence calculation image based on a value reflecting the fluorescence yield, the excitation light irradiation intensity distribution and the reference light irradiation intensity distribution are obtained, and the reference light irradiation intensity distribution is the excitation light irradiation intensity distribution. It has also been proposed to acquire an excitation light-corresponding reference light reflection image that would have been obtained if there was, improve the measurement accuracy of the reflection image, and acquire a more accurate fluorescence calculation image (see Patent Document 2). .

  On the other hand, as another fluorescence calculation image generation method, in Patent Document 3, red light or infrared light and blue light as excitation light are irradiated to a living tissue, and a reflected image of red light or infrared light, or a reflected image of blue light. The fluorescent image of the living tissue irradiated with the excitation light is captured, and the reflected image signal of red light is sent to the red signal channel of the display device, the reflected image signal of blue light is sent to the blue signal channel, and the fluorescent image signal Is input to the green signal channel to display a pseudo color image. With this configuration, the red light reflection image that reflects the illuminance distribution on the living body surface with a low absorptance on the living body surface is displayed in red, and the fluorescence image is displayed in green. Even when there is a fluorescence image, it is possible to obtain a fluorescent image corresponding to the tissue properties of the living body.

  In addition, if there is an inflamed part or a blood-concentrated part on the surface of the living body, the fluorescence in the green band and the excitation light in the blue band are absorbed, but the reflected image of the blue light that is the excitation light is reflected in the fluorescence image and the red light. Since it is displayed in combination with the image, even if there is an inflamed part or blood region where the fluorescence is absorbed, it is reflected in the display image as a blue density, so it is clearly displayed separately from the lesioned part. ing.

  Similarly, in Patent Document 4, an image signal on the long wavelength side of reflected light (wavelength band including a non-absorption band of hemoglobin light) is applied to the B channel of the RGB channel, an image signal of a fluorescent image is transmitted to the G channel, and reflected light is transmitted to the R channel. An image signal on the short wavelength side (wavelength band including the absorption band of hemoglobin light) is assigned to generate a composite image by synthesizing as one image, and between the normal tissue and the diseased tissue displayed on the composite image It is described that the gains of three input image signals are adjusted so that a hue boundary is included in a predetermined range with respect to the CIE 1976 UCS chromaticity diagram.

  In Patent Document 5, in order to correct the excitation light illuminance distribution due to the unevenness on the surface of the living body and the decrease in fluorescence intensity due to the absorption of fluorescence by blood, a reflected image of red light and a reflected image of blue light are acquired for each pixel. It is described that the intensity ratio between the two is taken and the fluorescence yield image reflecting the fluorescence yield is corrected based on the intensity ratio.

  Furthermore, in Non-Patent Document 1, as a result of obtaining and verifying the spectrum of fluorescence emitted from a living body for each point, the degree of absorption and scattering of fluorescence emitted from a measured living body varies depending on the wavelength band. It has been reported. In addition, due to the unevenness of the surface of the subject, the distribution of the incident angle of the excitation light on the surface of the living body changes the degree of absorption and scattering, and furthermore, the fluorescence intensity obtained changes depending on the distance between the measurement system and the subject, Due to these effects, the fluorescence spectrum acquired by the detector is distorted from the fluorescence spectrum originally emitted from the living body.

For this reason, in Non-Patent Document 1, a reflection spectrum on the surface of a living body is measured, and distortion of the fluorescence spectrum is corrected using the reflection spectrum.
JP 2002-172082 A JP2003-528 JP 2002-301009 A JP 2004-24611 A Special Table 2002-535025 Publication O plus E Vol.20, No.7 p836-840 (1998/7)

  However, conventional fluorescent imaging devices including the above-mentioned Patent Documents 1 to 5 do not take into account the fluorescence spectrum distortion due to the wavelength dependency of fluorescence absorption and scattering in the living body as described above, and the specific wavelength. When generating a fluorescence calculation image that reflects the tissue properties based on the intensity of the fluorescence, there is a possibility that the image does not accurately reflect the original tissue properties.

  Non-Patent Document 1 describes that the reflection spectrum on the surface of the living body is measured and the fluorescence spectrum is corrected. However, the fluorescence measurement from the living body is acquired using the point spectrum, and a fluorescence calculation image is generated. No specific structure for doing this is described.

  The present invention has been made in view of the above circumstances, and reduces the influence of the distortion of the fluorescence spectrum caused by the scattering of the fluorescence in the measured portion, which occurs when acquiring the above-described fluorescence image with a simple configuration, It is an object of the present invention to provide a fluorescence image capturing apparatus that can output a fluorescence correction image that more accurately reflects the tissue properties of a measured part.

  The first fluorescence image capturing apparatus of the present invention captures a fluorescence image based on the intensity of fluorescence in a predetermined wavelength band among the fluorescence generated from the measured portion by irradiating the measured portion with excitation light. Reflection that captures a reflected image based on the intensity of the reflected light in the predetermined wavelength band out of the reflected light reflected from the measured part by irradiating the image pickup means and the reference light including the predetermined wavelength band Image capturing means, and fluorescence correction image generation means for performing calculation based on the fluorescence image and the reflection image and outputting a fluorescence correction image in which the intensity of fluorescence in the predetermined wavelength band depending on the wavelength is corrected are provided. It is characterized by this.

  Here, “reference light including a predetermined wavelength band” may be reference light having the same wavelength band as the predetermined wavelength band, or may be reference light having a wavelength band wider than the predetermined wavelength band. That is, any reference light having a wavelength band including all the predetermined wavelength bands may be used. Note that the wavelength band including all the predetermined wavelength bands does not necessarily include all the predetermined wavelength bands, and may be any wavelength band including substantially all the predetermined wavelength bands.

  The first fluorescence imaging apparatus may further include a tissue property image generating unit that assigns color information to the fluorescence correction image and generates a tissue property image representing the tissue property of the measured part. be able to.

  The first fluorescence imaging apparatus may further include tissue shape image generation means for assigning luminance information to the reflected image and generating a tissue shape image representing the tissue shape of the measurement target. Can do.

  Further, in the first fluorescence image capturing device, a tissue shape image generating unit that assigns luminance information to the reflected image and generates a tissue shape image representing a tissue shape of the measurement target portion, the tissue property image, and the The image processing apparatus may further include a composite image generation unit that generates a composite image by combining the tissue shape image.

  Further, the calculation based on the fluorescence image and the reflection image by the fluorescence correction image generation means can be a division of the fluorescence image and the reflection image.

  The second fluorescence image capturing apparatus of the present invention is a first fluorescence image based on the intensity of fluorescence in the first wavelength band among the fluorescence generated from the measured portion by irradiating the measured portion with excitation light. Of the first wavelength band out of the reflected light reflected from the measured portion by irradiating the first reference light including the first wavelength band and the first reference light including the first wavelength band. A first reflected image capturing means for capturing a first reflected image based on the light intensity; and a fluorescence intensity in a second wavelength band different from the first wavelength band among the fluorescence generated from the measured part. A second fluorescent image capturing means for capturing a second fluorescent image based on the reflected light reflected from the measured part by irradiating the second reference light including the second wavelength band; The second reflection image is captured based on the intensity of the reflected light in the second wavelength band. A first reflection correction image obtained by performing calculation based on the two reflection image capturing means, the first fluorescence image and the first reflection image, and correcting the intensity of the fluorescence in the first wavelength band depending on the wavelength; The second fluorescence correction image generating means for outputting, the second fluorescence image and the second reflection image are calculated based on the second fluorescence image, and the second fluorescence band is corrected in intensity in the second wavelength band depending on the wavelength. Second fluorescence correction image generation means for outputting a fluorescence correction image; and fluorescence calculation image generation means for generating a fluorescence calculation image by performing calculation based on the first fluorescence correction image and the second fluorescence correction image. It is characterized by having.

  Here, the “second wavelength band different from the first wavelength band” may be any wavelength that does not completely match the first wavelength band, and the second wavelength band is the first wavelength band. In addition to the case where there is no band overlapping with the wavelength band, there may be a band where the second wavelength band partially overlaps with the first wavelength band, and the second wavelength band is a wide band including the first wavelength band. It may be anything.

The second fluorescence image capturing apparatus may further include a tissue property image generating unit that assigns color information to the fluorescence calculation image and generates a tissue property image representing the tissue property of the measured part. .

  The second fluorescence image capturing apparatus further includes tissue shape image generation means for assigning luminance information to the first or second fluorescence correction image and generating a tissue shape image representing the tissue shape of the measured part. Can be.

  In the second fluorescence image capturing apparatus, a tissue shape image generating unit that assigns luminance information to the first or second reflected image and generates a tissue shape image representing a tissue shape of the measurement target part, and the tissue The image processing apparatus may further include a composite image generating unit that generates a composite image by combining the property image and the tissue shape image.

  Further, the calculation based on the first fluorescence image and the first reflection image by the first fluorescence correction image generation means is a division of the first fluorescence image and the first reflection image, and the second The calculation based on the second fluorescence image and the second reflection image by the fluorescence correction image generation means can be a division of the second fluorescence image and the second reflection image.

  The fluorescence calculation image generation unit may generate a normalized fluorescence calculation image by dividing the first fluorescence correction image by the second fluorescence correction image.

  In addition, the fluorescence imaging apparatus can be in the form of an endoscope that is inserted into the living body through a hole in the living body.

  According to the first fluorescence image capturing apparatus of the present invention, a fluorescence image based on the intensity of fluorescence in a predetermined wavelength band among the fluorescence emitted from the measurement target unit by irradiating the measurement target unit such as biological tissue with excitation light. The reflected light image in the wavelength band in the same band as the fluorescent image is reflected out of the reflected light from the measured part obtained by irradiating the living body with the reference light including the same wavelength band as the predetermined wavelength band. To do.

  The captured fluorescent image may be affected by fluorescence spectrum distortion caused by absorption or scattering of fluorescence in a living body or a difference in distance between a measured part and a measurement system. On the other hand, since the wavelength band of the reflected light image is the same band as the wavelength band of the fluorescent image, when the fluorescence spectrum is distorted, the reflected light spectrum is also distorted in the same tendency. Become. That is, when the fluorescent image is affected by spectral distortion, it can be said that the reflected light image in the same wavelength band as the fluorescent image is also affected by the same fluorescent spectral distortion.

  Therefore, if a correction calculation is performed based on a fluorescent image and a reflected light image in the same wavelength band as that of the fluorescent image to generate a fluorescent corrected image, the reflectance reflecting the absorption or scattering of light in the wavelength of this band is added. A fluorescence correction image, that is, a fluorescence correction image in which the influence of distortion of the fluorescence spectrum is reduced can be obtained, and a fluorescence correction image that more accurately reflects the tissue properties of a living body can be obtained.

  In addition, by assigning color information to the fluorescence correction image and generating a tissue property image that represents the tissue property of the part to be measured, a tissue property image of the living body corrected for spectrum distortion due to fluorescence scattering in the living body is generated. can do. As a result, an image based on the tissue property image that more accurately reflects the tissue property of the living body can be displayed, and the observer can diagnose more accurately.

  Also, brightness information is assigned to the reflected image, and a tissue shape image representing the tissue shape of the measured part is generated and synthesized with the fluorescence correction image, so that the acquired image is obtained from the measured part on one composite image. The fluorescence corrected image obtained by correcting the fluorescence image and information related to the tissue shape of the measured part can be displayed, and the image in which the distortion of the spectrum due to absorption and scattering inside the living body is corrected is given to the observer. Can be displayed.

  In addition, color information is assigned to the fluorescence correction image, a tissue property image representing the tissue property of the measured part is generated, luminance information is assigned to the reflected image, and a tissue shape image representing the tissue shape of the measured part is generated. Since a composite image is generated by synthesizing the property image and the tissue shape image, by displaying this composite image, the observer can detect the fluorescence whose spectral distortion due to absorption and scattering inside the living body is corrected. Based on the tissue property image generated from the corrected image, more accurate information on the tissue property can be acquired. In addition, information on fluorescence (information on tissue properties) emitted from the measurement target and information on the tissue shape of the measurement target can be displayed on a single composite image, which can give the viewer a sense of discomfort. Absent.

  In addition, since the wavelength band of the reflected image and the wavelength band of the fluorescent image are the same, the reflected image can be captured using a wavelength band setting unit used when capturing the fluorescent image, for example, a band filter, etc. The configuration can be simplified.

  Further, by dividing the light intensity of the fluorescent image and the reflected image as the above calculation, the influence of the spectrum distortion can be canceled out by a simple calculation process, and a relatively accurate correction can be performed.

  According to the second fluorescence imaging apparatus of the present invention, the first fluorescence based on the intensity of the fluorescence in the first wavelength band among the fluorescence generated from the measurement target unit by irradiating the measurement target unit with excitation light. An image based on the intensity of the reflected light in the first wavelength band among the reflected light reflected from the measured part by irradiating the first reference light including the first wavelength band by capturing an image. 1 is captured, and a second fluorescence image based on the intensity of fluorescence in a second wavelength band different from the first wavelength band among the fluorescence generated from the measurement target is captured, and the second wavelength is captured. Taking a second reflected image based on the intensity of the reflected light in the second wavelength band out of the reflected light reflected from the measured part by irradiating the second reference light including the band, the first Calculating based on 1 fluorescence image and 1st reflection image, depending on wavelength Output a first fluorescence corrected image in which the intensity of fluorescence in the first wavelength band is corrected, perform a calculation based on the second fluorescence image and the second reflected image, and perform a second depending on the wavelength. A second fluorescence correction image in which the intensity of fluorescence in the wavelength band is corrected is output.

  In both the first fluorescence correction image and the second fluorescence correction image, the influence of the distortion of the fluorescence spectrum is reduced. Therefore, when generating a fluorescence calculation image based on the difference in the shape of the fluorescence spectrum reflecting the tissue properties of the living body based on the first fluorescence correction image and the second fluorescence correction image, It is possible to generate a fluorescence calculation image in which the influence of distortion of the fluorescence spectrum due to absorption or scattering is reduced, that is, a fluorescence calculation image that more accurately reflects the tissue properties of a living body. Moreover, the reliability of diagnosis can be improved by displaying an image based on this fluorescence calculation image.

  In addition, by assigning color information to the fluorescence calculation image obtained in this way and generating a tissue property image representing the tissue property of the measured part, the influence of the distortion of the spectrum shape due to the absorption and scattering of fluorescence in the living body can be reduced. It is possible to generate an image representing the reduced tissue properties of the living body, that is, a tissue property image that more accurately reflects the tissue properties of the living body. Further, by displaying this tissue property image, the observer can accurately diagnose.

  In addition, brightness information is assigned to the reflection image, and a tissue shape image representing the tissue shape of the measured part is generated and combined with the fluorescence calculation image, so that the tissue properties of the living body are reflected on one composite image. The fluorescence calculation image based on the difference in the shape of the fluorescence spectrum and the information on the tissue shape of the measured part can be displayed, and the fluorescence calculation with reduced influence of spectrum distortion due to absorption and scattering inside the living body An image can be displayed without giving an uncomfortable feeling to the observer.

  Further, color information is assigned to the fluorescence calculation image, a tissue property image representing the tissue property of the measured part is generated, luminance information is assigned to the reflected image, and a tissue shape image representing the tissue shape of the measured part is generated, Since a composite image obtained by synthesizing the property image and the tissue shape image is generated, more accurate information on the tissue property can be obtained based on the fluorescence image more faithful to the fluorescence emitted from the living body. The information related to the fluorescence emitted from the part to be measured (information related to the tissue property) and the information related to the tissue shape of the part to be measured can be displayed on the combined image, and the observer does not feel uncomfortable.

  Note that the wavelength band of the first reflected image and the wavelength band of the first fluorescent image are the same, and the wavelength band of the second reflected image and the wavelength band of the second fluorescent image are the same. A reflected image can be picked up using a wavelength band setting means, for example, a bandpass filter, used when taking an image, and the apparatus configuration can be simplified.

  Further, as the above calculation, by dividing the light intensity of the first fluorescent image and the first reflected image and by dividing the light intensity of the second fluorescent image and the second reflected image, the spectrum can be calculated by a simple calculation. Distortion can be canceled out, and relatively accurate correction can be performed.

  Furthermore, when the fluorescence imaging apparatus is in the form of an endoscope that is inserted into the living body through a hole in the living body, more accurate information can be obtained regarding the tissue properties of the organ in the living body.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a fluorescence endoscope apparatus according to a first embodiment to which a fluorescence imaging apparatus according to the present invention is applied.

  The fluorescence endoscope apparatus according to the present embodiment injects a fluorescent diagnostic agent that is selectively accumulated in a lesion in advance in a subject, irradiates the subject with excitation light including the excitation wavelength of the fluorescent diagnostic agent, and The fluorescence (drug fluorescence) emitted from the fluorescent diagnostic drug in the sample is imaged. The fluorescence endoscope apparatus according to the first embodiment CCDs the reflected light reflected from the measurement target by irradiation of illumination light Lw (Lr, Lg, Lb, Lir) from the blue light region to the near infrared light region. A normal image is picked up by the image pickup device 107 and displayed on the monitor 161. On the other hand, a fluorescence image based on the fluorescence emitted from the measurement target due to the excitation light irradiation is picked up by the CCD image pickup device 107, and the same as the fluorescence. IR light Lir, which is near-infrared light included in the illumination light Lw, is used as reference light having a wavelength in the band, and reflected light L7 reflected from the measurement target 50 by irradiation of the IR light Lir is the same as the fluorescence wavelength. Captured as a band reflection image, calculated a fluorescence correction image based on the division value of the fluorescence image and the fluorescence wavelength same band reflection image, and assigned a hue H based on the pixel value of the fluorescence correction image to generate a tissue property image And also fluorescent A tissue shape image is generated by assigning saturation S and lightness V based on the pixel value of the long-band reflection image, and the tissue property image and the composite image based on the tissue shape image are displayed on the monitor 162. .

  The fluorescence endoscope apparatus according to the first embodiment of the present invention is provided with a CCD imaging device 107 at the tip, and an endoscope insertion unit 100 to be inserted into a site suspected of being a patient's lesion, normal image imaging Illumination unit 110 that emits illumination light Lw including RGB light (Lr, Lg, Lb) for light and reference light (Lir) in the same wavelength band as fluorescence, and excitation light L22 for imaging fluorescent images, and the fluorescence image A division value of the reflection image in the same band as the fluorescence wavelength is calculated, a hue H is assigned to the fluorescence correction image based on the division value to generate a tissue property image, and the pixel value of the reflection image in the same band as the fluorescence wavelength is colored. An image for displaying a normal image and a composite image as a visible image, generating a tissue shape image by assigning degrees and brightness, and synthesizing the tissue property image and the tissue shape image to generate a composite image place An image processing unit 140 that performs the control, a control computer 160 that is connected to each unit and controls the operation timing, a monitor 161 that displays a normal image processed by the image processing unit 140 as a visible image, and an image processing unit 140 The monitor 162 is configured to display the processed composite image as a visible image.

  The endoscope insertion unit 100 includes a light guide 101 and a CCD cable 102 that extend to the tip. An illumination lens 104 and an objective lens 105 are provided at the distal end portions of the light guide 101 and the CCD cable 102, that is, at the distal end portion of the endoscope insertion portion 100. Further, a CCD image sensor 107 is connected to the tip of the CCD cable 102, and a mosaic filter 106 as shown in FIG. 2 is formed on the CCD image sensor 107, and a prism 108 is further attached. . An excitation light cut filter 109 is disposed between the objective lens 105 and the prism 108. In the light guide 101, a white light light guide 101a that is a multi-component glass fiber and an excitation light light guide 101b that is a quartz glass fiber are bundled and integrated into a cable shape, and the white light light guide 101a and the excitation light light guide are integrated. 101 b is connected to the lighting unit 110.

  In the CCD cable 102, a drive line 102a to which a drive signal for the CCD image sensor 107 is transmitted and an output line 102b for reading a signal from the CCD image sensor 107 are combined, and one end of the drive line 102a is connected to the control computer 160. One end of the output line 102 b is connected to the composite image unit 180 and the image processing unit 140.

  As shown in FIG. 2, the mosaic filter 106 includes an R filter 106a that transmits R light, a G filter 106b that transmits G light, a B filter 106c that transmits B light, and a 780-900 nm infrared light. The infrared filters 106d are arranged in a mosaic pattern, and each filter is arranged so as to correspond to one pixel of the CCD image sensor.

  The illumination unit 110 includes a white light source 111 that emits illumination light Lw that includes near-infrared light in the same band as RGB light and fluorescence, a white light source power source 112 that is electrically connected to the white light source 111, and a white light source 111. Condensing lens 113 for condensing the illumination light Lw from the guide fiber 101a, an AlGaAs semiconductor laser 114 for emitting excitation light L22 for fluorescent image capturing, and a semiconductor laser electrically connected to the AlGaAs semiconductor laser 114 And a condensing lens 116 that condenses the laser light from the semiconductor laser 115 onto the guide fiber 101b.

  The composite image generation unit 180 is irradiated with the excitation light L22 or the illumination light Lw and receives near-infrared light in the same band as the fluorescence and fluorescence. An A / D conversion circuit 181 that digitizes the image signal of the infrared light image, an image memory 182 that stores the fluorescence image and the fluorescence wavelength same-band reflection image in different storage areas, and a fluorescence image stored in the image memory 182 A division value for each corresponding pixel of the fluorescence wavelength same-band reflection image is calculated to generate a fluorescence corrected image, and the range of the division value and the hue H (0 rad to 2/3 rad, Red to Yellow to Green in the Munsell hue ring) are previously generated. A look-up table corresponding to each region) is stored, and a fluorescence correction image / texture property is generated by assigning a hue H as color information to the value (divided value) of each pixel of the fluorescence correction image to generate a tissue property image. Lookup in which the pixel value range of the reflected image and the brightness V (Value) in the Munsell color system correspond to each pixel value of the fluorescence wavelength same-band reflected image stored in the image generation unit 183 and the image memory 182 in advance. A table is stored, a brightness V as luminance information is assigned to the reflected image, a saturation S (Saturation) is set from the hue H and the brightness V, and a tissue shape image generating means 185 for generating a tissue shape image, fluorescence correction A composite image generation unit 184 is provided that combines the tissue property image output from the image / tissue property image generation unit 183 and the tissue shape image output from the tissue shape image generation unit 185 and outputs the combined image.

  The image processing unit 140 is irradiated with the illumination light Lw, and an A / D conversion circuit 142 that digitizes an image signal in which an image of the R light Lr, the G light Lg, or the B light Lb is captured by the CCD image sensor 107. The normal image memory 143 for storing the normal image for each color, and when displaying the normal image, the three color image signals output in synchronization from the normal image memory 143 are converted into video signals. When a fluorescent image is displayed, a video signal processing circuit 144 that converts the synthesized image output from the synthesized image generation unit 180 into a video signal and outputs the video signal is provided.

  In the embodiment of the present invention, as a fluorescent diagnostic agent to be injected into a living body in advance, three or more sulfonic acid groups are introduced into the cyanine dye compound described in JP-A-2003-160558 and JP-A-200-261464. An infrared fluorescent contrast agent containing a sodium salt is used. This fluorescent contrast agent emits fluorescence in a wavelength region of 750 to 900 nm that is less absorbed by a living body and excellent in transparency when irradiated with excitation light having a wavelength of 700 to 850 nm. In that case, as the excitation light for exciting the drug, the fluorescent diagnostic drug is irradiated efficiently with excitation light having a wavelength band of 750 nm to emit fluorescence. In this embodiment, an AlGaAs semiconductor laser that emits a wavelength of 750 nm is used as an excitation light source, but an AlGaInP system that outputs a laser having the same wavelength band may be used as an excitation light source.

  Next, the operation of the fluorescence endoscope apparatus in the above embodiment will be described. In this fluorescence endoscope apparatus, normal image capturing and fluorescent image capturing are performed in a time-sharing manner, and the fluorescence wavelength in-band reflected image is simultaneously captured when the normal image is captured. A normal image based on the normal image is displayed on the monitor 161, and a composite image based on the fluorescence image and the fluorescence wavelength same-band reflected light image is displayed on the monitor 162. In order to capture each image in a time-sharing manner, illumination light Lw and excitation light L22 are sequentially emitted from the illumination unit 110.

  First, the operation when displaying a normal image will be described. The reflected light L7 of the illumination light Lw that is irradiated with the illumination light Lw and reflected by the measurement target 50 is formed on the CCD image sensor 107 as a reflected image. Here, a mosaic filter 106 having an arrangement as shown in FIG. 2 is formed on the CCD image sensor 107 on-chip. In the mosaic filter, filters 106a, 106b, 106c, and 106d that respectively transmit R light, G light, B light, and IR light out of the reflected light L7 of the illumination light Lw are arranged in a pattern as shown in FIG. The reflected light L7 imaged on the filter is R light by the light receiving element immediately below the filter 106a of the CCD image pickup device, G light by the light receiving element immediately below the filter 106b, and B by the light receiving element immediately below the filter 106c. IR light having a wavelength in the same band as fluorescence is received and photoelectrically converted by the light and the light receiving element immediately below the filter 106d. The R, G, B, and image signals photoelectrically converted by the CCD image sensor 107 are converted into digital signals by the A / D conversion circuit 142, and the R image signal storage area and the G image signal storage in the normal image memory 143 are stored. It is stored in the storage area of the area and the B image signal. The IR image signal is converted into a digital signal by the A / D converter 181 and stored as a fluorescence wavelength in-band reflected image in the storage area of the fluorescence wavelength in-band reflected image signal of the image memory 182.

  When the three-color image signals are stored in the normal image memory 143, they are output in synchronization with the display timing, converted into video signals by the video signal processing circuit 144, output to the monitor 161, and color signals. Displayed as an image.

  Next, the operation of generating and displaying a composite image based on the fluorescence image and the fluorescence wavelength same-band reflection image will be described. At the time of fluorescent image capturing, the semiconductor laser power source 115 is driven based on a signal from the control computer 160, and excitation light L22 having a wavelength of 750 nm is emitted from the AlGaAs semiconductor laser 114. The excitation light L22 passes through the lens 116, is incident on the excitation light light guide 101b, is guided to the distal end of the endoscope insertion portion, and is then irradiated from the illumination lens 104 to the measured portion 50.

  The fluorescence L32 from the measurement target 50 generated by the irradiation with the excitation light L22 is collected by the condenser lens 105, reflected by the prism 108, and formed on the CCD image sensor 107 as a fluorescent image. At this time, the reflected light of the excitation light L22 is cut by the excitation light cut filter 109 and therefore does not enter the CCD image sensor 107. The excitation light cut filter blocks light having a wavelength of 720 nm to 780 nm including the band of the excitation light L22 having a wavelength of 750 nm. When the upper limit of the band of the drug fluorescence L32 substantially matches the upper limit of the band of illumination light, the excitation light cut filter may not be provided as long as the transmission band of the IR filter 106d on the mosaic filter is 770 nm or more.

  The image signal received and photoelectrically converted by the light receiving element immediately below the filter 106d of the CCD image sensor 107 is converted into a digital signal by the A / D conversion circuit 181 of the composite image generation unit 180, and the fluorescence of the image memory 182 is converted. It is stored in the image storage area. On the other hand, the image memory 182 has already stored a fluorescence wavelength same-band reflected image having the same band as the fluorescence wavelength captured at the time of the normal image capturing.

  In the fluorescence correction image / tissue property image generation means 183, first, the pixel value of the fluorescence image is divided by the pixel value of the fluorescence wavelength same-band reflection image for each pixel to generate a fluorescence correction image. Next, using a lookup table stored in advance, a hue characteristic in the Munsell color system is assigned to the pixel value of the fluorescence correction image, that is, the division value, and a tissue property image is generated, and output to the composite image generation means 184 To do.

  Further, the tissue shape image generation means 185 uses the pixel value and the lookup table for each pixel of the fluorescence wavelength same-band reflection image stored in the fluorescence wavelength same-band reflection image storage area of the image memory 182, and uses the Munsell. A tissue shape image is generated by assigning brightness V in the color system, and is output to the composite image generation means 184. When an image is displayed in color, the three attributes of color, hue, lightness, and saturation, are necessary. Therefore, in the image composition, each saturation S (Saturation) in the Munsell color system is Set the maximum value for each hue and brightness.

  The composite image generation means 184 combines the tissue characteristic image with the tissue shape image based on the lightness V and the saturation S to generate a composite image. Note that, when an image is displayed in color, RGB conversion is performed to generate a composite image and output it to the video signal processing circuit 144.

  The composite image converted into the video signal by the video signal processing circuit 144 is input to the monitor 161 and displayed on the monitor 161 as a visible image. The above series of operations is controlled by the control computer 160.

  The composite image generated according to the present embodiment is, for example, bright bright green for a normal tissue whose distance from the distal end of the endoscope insertion portion to the measurement target is short, and for a normal tissue whose distance is far, A dark green with no taste, a vivid bright red is displayed for a lesion tissue with a close distance, and a dark red with no color is displayed for a lesion tissue with a long distance.

  In the present embodiment, the tissue shape image generation unit 185 generates the tissue shape image by assigning the lightness V in the Munsell color system to each pixel of the fluorescence wavelength same-band reflected image. It may be obtained separately and a tissue shape image may be generated based on this reflection image.

  Next, a fluorescence endoscope apparatus according to a second embodiment to which the fluorescence imaging apparatus of the present invention is applied will be described with reference to FIG. The fluorescence endoscope apparatus according to the second embodiment of the present invention images autofluorescence emitted from a subject by irradiating a living body with predetermined excitation light, and the autofluorescence from the living body is normal tissue. The fluorescence calculation image is generated and displayed by applying the fact that the intensity and spectrum are different in the lesion tissue.

  The fluorescence endoscope apparatus according to the present embodiment includes an endoscope insertion unit 200 that is inserted into a site suspected of being a patient's lesion, a light source that emits white light for capturing normal images and reflected images, and excitation light for capturing fluorescent images. A lighting unit 210 comprising: a narrow-band fluorescent image, a broadband fluorescent image, an imaging unit 220 that captures a narrow-band reflected image and a broadband reflected image, a division value of the narrow-band fluorescent image by the narrow-band reflected image is calculated and the divided value is Fluorescence corrected image generation unit 250 for generating a divided-band fluorescence correction image based thereon and a divided value of the broadband fluorescent image by the broadband reflected image and generating a broadband fluorescent correction image based on the divided value, and further, the narrow-band fluorescence corrected image Then, a division value based on the broadband fluorescence corrected image is calculated, a hue is assigned to the calculation image based on the division value, and a tissue property image is generated. A composite image generation unit 230 that generates a tissue shape image by assigning brightness V to a value, combines the tissue property image and the tissue shape image to generate a composite image, and displays the normal image and the composite image as a visible image An image processing unit 240 that performs image processing, a control computer 260 that is connected to each unit and controls operation timing, a monitor 261 that displays a normal image processed by the image processing unit 240 as a visible image, and an image processing unit 240 It is comprised from the monitor 262 which displays the synthesized image processed by (4) as a visible image.

  The endoscope insertion unit 200 includes a light guide 201 extending to the tip, a CCD cable 202, and an image fiber 203 inside. An illumination lens 204 and an objective lens 205 are provided at the distal end portions of the light guide 201 and the CCD cable 202, that is, at the distal end portion of the endoscope insertion portion 200. The image fiber 203 is a quartz glass fiber, and a condensing lens 206 is provided at the tip thereof. A CCD image sensor 207 is connected to the tip of the CCD cable 202, and a prism 208 is attached to the CCD image sensor 207. The light guide 201 is bundled with a white light light guide 201a that is a multi-component glass fiber and an excitation light light guide 201b that is a quartz glass fiber, and is integrated into a cable shape, and the white light light guide 201a and the excitation light light guide 201b are integrated. Are connected to the lighting unit 210. One end of the CCD cable 202 is connected to the image processing unit 240, and one end of the image fiber 203 is connected to the imaging unit 220.

  The illumination unit 210 includes a white light source 211 that emits white light L1 for capturing a normal image, a narrow-band reflected image, and a broadband reflected image, a white light source 212 that is electrically connected to the white light source 211, and a white light source 211. Lens 213 for condensing and entering the white light into the light guide 201a, a GaN-based semiconductor laser 214 that emits excitation light L21 for fluorescent image capturing, and a semiconductor laser that is electrically connected to the GaN-based semiconductor laser 214 And a condensing lens 216 for condensing and entering laser light from the semiconductor laser 214 to the light guide 201b.

  The wavelength of the excitation light L21 is preferably 350 nm to 450 nm, and more preferably 400 nm to 420 nm, in order to obtain the intensity of autofluorescence. In this embodiment, excitation light L21 of 405 nm to 410 nm is emitted by a GaN semiconductor laser.

  The imaging unit 220 includes an excitation light cut filter 221 that cuts a wavelength band of 420 nm or less, which is a wavelength near the excitation light, from the fluorescence L31 that has passed through the image fiber 203, a switching filter 222 that is a combination of two types of optical filters, and the switching filter A filter rotating device 224 that rotates 222, a CCD image sensor 225 that captures a fluorescent image or a reflected image that has passed through the switching filter 222, and A / D conversion that digitizes the fluorescent image and the reflected image captured by the CCD image sensor 225. And an image memory 227 for storing an image signal digitized by the circuit 226 and the A / D conversion circuit 226.

  The switching filter 222 includes an optical filter 223a that is a bandpass filter that transmits light of 480 nm ± 50 nm and an optical filter 223b that is a bandpass filter that transmits light of 430 nm to 730 nm as shown in FIG. ing. The optical filter 223a is an optical filter for narrow-band imaging, and the optical filter 223b is an optical filter for broadband imaging. The switching filter 222 is connected via the filter rotation device 224 so that the optical filter 223a or the optical filter 223b is alternately arranged when the white light L1 is irradiated and when the excitation light L21 is irradiated. Are controlled by the control computer 260.

  The CCD image pickup device 225 is a 500 × 500 pixel image pickup device, and performs normal readout when taking a reflected image under the control of the control computer 260, but takes a fluorescent image when taking a fluorescent image. In order to increase the signal intensity, binning reading is performed after adding the outputs of 5 × 5 pixels. For this reason, when a fluorescent image is captured, it apparently operates as a 100 × 100 pixel image sensor.

  The image memory 227 includes a narrowband fluorescent image storage area, a broadband fluorescent image storage area, a narrowband reflection image storage area, and a broadband reflection image storage area (not shown). The image memory 227 is irradiated with excitation light L21 and is used for narrowband image capturing. The fluorescence image captured in a state where the optical filter 223a is disposed on the optical path is stored in the narrow-band fluorescence image storage area, irradiated with the excitation light L21, and the optical filter 223b for broadband image capturing is disposed on the optical path. The fluorescent image captured in the state is stored in the broadband fluorescent image storage area. Further, the reflected image captured with the white light L1 and the optical filter 223a for narrow-band image capturing disposed on the optical path is stored in the narrow-band reflected image storage area, and the white light L1 is irradiated and the broadband The reflected image captured in a state where the optical filter 223b for image capturing is arranged on the optical path is stored in the broadband reflected image storage area.

  As described above, since the readout methods are different, the number of pixels of the narrowband reflected image and the broadband reflected image is 500 × 500 pixels, and the number of pixels of the narrowband fluorescent image and the broadband fluorescent image is 100 × 100 pixels.

  The fluorescence correction image generation unit 250 reads the narrowband fluorescence image and the narrowband reflection image recorded in the respective areas in the image memory 227, divides the narrowband fluorescence image for each pixel by the narrowband reflection image, and A narrow-band fluorescence corrected image means generating unit 251 that generates a band-fluorescence corrected image, reads out the broadband fluorescence image and the broadband reflection image, and divides the broadband fluorescence image for each pixel by the broadband reflection image to generate a broadband fluorescence correction image. It consists of a broadband fluorescence corrected image generation means 252.

  The composite image generation unit 230 first generates a fluorescence calculation image composed of a division value between the fluorescence images, and previously calculates a hue H (0 rad to 2/3 rad, Red to Yellow to Green in the range of the division value and the hue ring of Munsell. A fluorescence calculation image / tissue property image generation unit 231 that generates a tissue property image by assigning a hue H to a value (divided value) for each pixel of the fluorescence calculation image. A look-up table corresponding to the range of pixel values of the broadband reflection image and the brightness V (Value) in the Munsell color system is stored, and the tissue shape image is generated by assigning the brightness V to the broadband reflection image. The generating unit 232 includes a composite image generating unit 233 that generates a composite image based on the two images.

  The image processing unit 240 includes an A / D conversion circuit 241 that digitizes a normal image captured by the CCD image sensor 207 disposed at the distal end of the endoscope, and a normal image memory 243 that stores the digitized normal image. A video signal processing circuit 244 for converting the normal image output from the normal image memory 243 and the synthesized image synthesized by the synthesized image generating means 233 into a video signal is provided.

  The operation of the fluorescence endoscope apparatus having the above configuration to which the fluorescence display apparatus according to the present invention is applied will be described below. In the fluorescence endoscope apparatus according to the present embodiment, the normal image and the reflected image are captured and the fluorescent image is alternately captured in a time division manner. First, an operation when capturing the normal image and the reflected image will be described.

  In the present fluorescence endoscope apparatus, during normal imaging, the white light source power supply 212 is driven based on a signal from the control computer 260, and the white light L1 is emitted from the white light source 211. The white light L1 enters the white light guide 201a through the white light condensing lens 213, is guided to the distal end of the endoscope insertion portion, and is irradiated from the illumination lens 204 to the measurement target 50. The reflected light L7 of the white light L1 is collected by the condenser lens 205, reflected by the prism 208, imaged on the CCD image pickup device 207, and received by the CCD image pickup device 207. The video signal photoelectrically converted by the CCD 207 is converted into a digital signal by the A / D conversion circuit 241 in the image processing unit 240 and stored in the normal image memory 243. The normal image signal stored in the normal image memory 243 is converted into a video signal by the video signal processing circuit 244 and then input to the monitor 261 and displayed on the monitor 261 as a visible image. The above series of operations is controlled by the control computer 260. In this way, a normal image is displayed.

  The reflected light L4 of the white light L1 when irradiated to the part to be measured 50 is also collected by the condenser lens 206, is incident on the tip of the image fiber 203, and is condensed by the lens 228 through the image fiber 203. Then, it passes through the narrowband optical filter 223 a or the broadband optical filter 223 b of the excitation light cut filter 221 and the switching filter 222.

  The narrow band reflected image transmitted through the optical filter 223 a or the broadband reflected image transmitted through the optical filter 223 b is formed by the lens 229 and received by the CCD image sensor 225. The narrowband reflection image and the broadband reflection image photoelectrically converted by the CCD image pickup device 225 are converted into digital signals by the A / D conversion circuit 226, and then the narrowband reflection image storage region and the broadband reflection image storage region of the image memory 227. Are stored respectively.

  Next, the operation at the time of capturing a fluorescent image will be described. Based on the signal from the control computer 260, the semiconductor laser power source 215 is driven, and the GaN-based semiconductor laser 214 emits excitation light L21 having a wavelength of 405 nm to 410 nm. The excitation light L21 passes through the excitation light condensing lens 216, enters the excitation light light guide 201b, is guided to the distal end of the endoscope insertion portion, and is irradiated from the illumination lens 204 to the measured portion 50. .

  Fluorescence L31 from the measurement target 50 generated by irradiating the excitation light L21 is condensed by the condenser lens 206, is incident on the tip of the image fiber 203, is condensed by the lens 228 through the image fiber 203. The excitation light cut filter 221 and the switching filter 222 are transmitted through the narrow band optical filter 223a or the broadband optical filter 223b.

  The optical filter 223a is a bandpass filter that transmits light having a wavelength band of 480 ± 50 nm, and the fluorescence transmitted through the optical filter 223a becomes a narrowband fluorescent image. The optical filter 223b is a bandpass filter that transmits light having a wavelength band of 430 nm to 730 nm, and the fluorescence transmitted through the optical filter 223b becomes a broadband fluorescent image.

  The broadband fluorescent image and the narrow-band fluorescent image are received by the CCD image pickup device 225, subjected to photoelectric conversion, and then read by adding signals of 5 × 5 pixels by binning readout, and digitally output by the A / D conversion circuit 226. It is converted into a signal and stored in the broadband fluorescent image storage area and the narrowband fluorescent image storage area of the image memory 227. By performing binning readout as described above, it is possible to accurately capture a fluorescent image with low light intensity. However, the number of pixels of the fluorescence image is 100 × 100 pixels, which is 1/25 that of normal readout. Become.

  Next, the operation of generating a fluorescence correction image will be described. First, in the narrow band fluorescence correction image generation unit 251 of the fluorescence correction image generation unit 250, the narrow band reflection image storage of the image memory 227 is also stored for the narrow band fluorescence image stored in the narrow band fluorescence image storage area of the image memory 227. The pixel value in the narrow-band fluorescence image is divided by the pixel value in the narrow-band reflection image for each pixel by the narrow-band reflection image stored in the region to generate a narrow-band fluorescence correction image for the narrow-band fluorescence image. Further, in the broadband fluorescence corrected image generation means 252, each of the broadband fluorescence images stored in the broadband fluorescence image storage area of the image memory 227 is subjected to each of the broadband reflection images similarly stored in the broadband reflection image storage area of the image memory 227. For each pixel, the pixel value in the broadband fluorescence image is divided by the pixel value in the broadband reflection image to generate a broadband fluorescence correction image for the broadband fluorescence image.

  Next, the operation of generating a composite image will be described. In the fluorescence calculation image / tissue property image generation means 231 of the composite image generation unit 230, for each pixel of the narrowband fluorescence correction image and the broadband fluorescence correction image generated by the fluorescence correction image generation means, in the narrowband fluorescence correction image. The pixel value is divided by the pixel value in the broadband fluorescence correction image to generate a fluorescence calculation image, and the value for each pixel of the fluorescence calculation image, that is, the division value and a pre-stored lookup table are used to display the Munsell color A tissue property image is generated by assigning a hue H (Hue) in the system, and is output to the composite image generation means 233.

  Further, the tissue shape image generation means 232 uses the pixel value and the lookup table for each pixel of the broadband reflected image stored in the broadband reflected image storage area of the image memory 227, and the brightness V in the Munsell color system. To generate a tissue shape image and output it to the composite image generation means 233.

  The composite image generation unit 233 converts the data of one pixel of the tissue characteristic image into data of 5 × 5 pixels, expands the number of pixels of the tissue characteristic image from 100 × 100 pixels to 500 × 500 pixels, and then Then, the tissue shape image and the tissue shape image based on the brightness V are combined to generate a combined image. When an image is displayed in color, the three attributes of color, hue, lightness, and saturation, are necessary. Therefore, in the image composition, each saturation S (Saturation) in the Munsell color system is Set the maximum value for each hue and brightness. Thereafter, RGB conversion is performed to generate a composite image and output it to the video signal processing circuit 244.

  The composite image converted into the video signal by the video signal processing circuit 244 is input to the monitor 262 and displayed on the monitor 262 as a visible image. The above series of operations is controlled by the control computer 260.

  Due to the above-described operation, the hue of the displayed composite image reflects the division value of the pixel value between the two types of fluorescence correction images, that is, the difference in the shape of the fluorescence spectrum of the fluorescence emitted from the measurement target 50. Therefore, the brightness reflects the pixel value of the broadband reflected image, that is, the shape of the measured part 50, so that information on the fluorescence emitted from the measured part 50 is included in one image. Information about the shape of the measurement unit can be displayed, and the viewer does not feel uncomfortable. Therefore, the observer can easily determine the tissue properties of the measured part.

  Further, by setting the hue H in the Munsell hue ring based on the division value of the pixel values between the fluorescent images, the division value of the pixel values can be easily made to correspond only to the hue, and the fluorescence of the fluorescence can be accurately detected. Differences in the shape of the fluorescence spectrum can be reflected in the composite image.

  Furthermore, since the fluorescent image is read out by binning readout at the time of imaging, the number of pixels of the fluorescent image is 100 × 100 pixels. However, when generating the composite image, the data of one pixel of the tissue property image is converted to 5 pixels. The data is converted into data of × 5 pixels, the number of pixels of the tissue characteristic image is expanded from 100 × 100 pixels to 500 × 500 pixels, and then the tissue shape image and the tissue shape image based on the lightness V are synthesized. Since the composite image is generated, the number of pixels of the display image corresponds to 500 × 500 pixels, and the shape of the measured part can be clearly displayed.

  Further, since the GaN-based semiconductor laser 114 is used as the light source of the excitation light L21, the excitation light can be irradiated with an inexpensive and small light source. In addition, since the wavelength of the excitation light is set to 405 nm to 410 nm, fluorescence is efficiently emitted from the measured part 50.

  In the second embodiment, fluorescence in the band of 480 ± 50 nm is acquired as the narrow-band fluorescence image, but may be acquired in other bands. Further, in the low wavelength band of 580 nm or less, the degree of fluorescence scattering and absorption is large and the distortion of the fluorescence spectrum is large, so that a more remarkable effect can be obtained when acquiring a low wavelength of 580 nm or less.

  As a modified example of the second embodiment, when a composite image is generated, a lookup table in which hue values are stored in advance corresponding to a division value between fluorescent images and a division value between fluorescent images is prepared. Instead of determining the hue by using, it is possible to assign the hue H using a look-up table in which the pixel values and the hue H of two types of fluorescent images converted into unsigned 16 bits as shown in Table 1 are stored. It is done. In this case, since division between fluorescent images is not necessary, stable mathematical processing is possible even when the pixel value of the fluorescent image is small.

  As a second modification of the second embodiment, when generating a fluorescence calculation image, a configuration may be adopted in which a fluorescence correction image is generated only for either a narrow-band fluorescence image or a broadband fluorescence image. The fluorescence calculation image reflecting the tissue characteristics of the living body can be acquired. By adopting such a configuration, it is only necessary to acquire and calculate a reflection image in the same band as either the narrow-band fluorescence or the wide-band fluorescence, so that the apparatus can be configured in a simple manner, and the process of generating the fluorescence calculation image Can be speeded up. In that case, a more accurate fluorescence calculation image can be obtained by generating a fluorescence correction image only for a narrow-band fluorescence image whose fluorescence intensity is more sensitive to the deformation of the fluorescence spectrum.

  In the tissue shape image generation unit 232, the tissue shape image is generated by assigning the brightness V in the Munsell color system to each pixel of the wideband reflection image. However, the Munsell color specification is generated for each pixel of the narrowband reflection image. A tissue shape image may be generated by assigning brightness V in the system. Alternatively, a reflection image may be acquired separately, and a tissue shape image may be generated based on the reflection image.

  Next, a third embodiment to which the fluorescence imaging apparatus of the present invention is applied will be described with reference to FIG. The fluorescence endoscope apparatus to which the third embodiment is applied is emitted from a living body by irradiating the fluorescence from the fluorescent diagnostic agent acquired in the first embodiment and the excitation light acquired in the second embodiment. It is a fluorescence endoscope apparatus that can image self-fluorescence with the same fluorescence endoscope apparatus by switching the imaging mode.

  The fluorescence endoscope apparatus according to the present embodiment includes an endoscope insertion unit 300 inserted into a site suspected of being a patient's lesion, white light for capturing a normal image and a reflected image, and excitation for capturing an autofluorescent image from a living body. Illumination unit 310 having a light source that emits excitation light for imaging fluorescent light from fluorescent light and fluorescent diagnostic agents, auto-fluorescence imaging mode and drug fluorescence imaging for imaging auto-fluorescence images and drug fluorescence images An imaging mode switching unit 390 that switches modes, an autofluorescence image, a drug fluorescence image, and an imaging unit 320 that captures a reflection image in the same band as those wavelength bands, an autofluorescence image, and a fluorescence image of the drug fluorescence image, respectively. Fluorescence correction image generation means 351 that calculates a division value based on the reflection image and generates a fluorescence correction image based on the division value, and each fluorescence correction Assign a hue to the image to generate a tissue property image, assign a brightness V to the pixel value of the reflected image in the same band as each fluorescence wavelength, generate a tissue shape image, and synthesize the tissue property image and the tissue shape image A composite image generation unit 330 that generates a composite image, an image processing unit 340 that performs image processing for displaying a normal image and a composite image as a visible image, and a control computer 360 that is connected to each unit and controls operation timing. The monitor 361 displays a normal image processed by the image processing unit 340 as a visible image, and the monitor 362 displays the composite image processed by the image processing unit 340 as a visible image.

  The endoscope insertion unit 300 includes a light guide 301 extending to the tip, a CCD cable 302, and an image fiber 303 inside. An illumination lens 304 and an objective lens 305 are provided at the distal ends of the light guide 201 and the CCD cable 302, that is, at the distal end of the endoscope insertion unit 300. A condensing lens 306 is provided at the tip of the image fiber 303. A CCD image pickup device 307 is connected to the tip of the CCD cable 302, and a mosaic filter 309 shown in FIG. 7 is formed on the CCD image pickup device 307 on-chip on the CCD image pickup device 307.

  Further, a prism 308 is attached on the mosaic filter, and an image is formed on the mosaic filter. The light guide 301 includes a white light light guide 301a, a drug fluorescence excitation light light guide 301b, and an autofluorescence excitation light light guide 301c that are bundled and integrated in a cable shape. The white light light guide 301a and the excitation light light The guides 301b and 301c are connected to the illumination unit 310. One end of the CCD cable 302 is connected to the image processing unit 340, and one end of the image fiber 303 is connected to the imaging unit 320.

  The illumination unit 310 emits a normal image, a reflected image in the same band as two types of fluorescence having different wavelength bands among autofluorescence, and a white light that emits illumination light Lw for capturing a reflected image in the near infrared band in the same band as the drug fluorescence. A light source 311, a white light source 312 electrically connected to the white light source 311, a condensing lens 313 for condensing and entering white light from the white light source 311 into the light guide 301c, and excitation light for autofluorescence image capturing A GaN-based semiconductor laser 314 that emits L21, a semiconductor laser power source 315 that is electrically connected to the GaN-based semiconductor laser 314, and a condensing lens 316 that condenses and enters laser light from the semiconductor laser 314 into the light guide 301a. I have. Further, the laser light from the AlGaAs semiconductor laser 3 17 emitting the excitation light L22 of the fluorescent diagnostic agent, the semiconductor laser power source 318 electrically connected to the AlGaAs semiconductor laser 3 17 and the semiconductor laser 317 is condensed on the light guide 301b. And a condensing lens 319 for incidence.

  As in the case of the first embodiment, the fluorescent contrast agent is cyanine that emits fluorescence in the wavelength region of 750 to 900 nm, which is less absorbed by a living body and excellent in transparency when irradiated with excitation light having a wavelength of 700 to 850 nm. An infrared fluorescent contrast agent containing a sodium salt in which three or more sulfonic acid groups are introduced into the dye compound is used.

  As the excitation light wavelength, similarly to the first and second embodiments, 405 nm to 410 nm excitation light L21 by the self-fluorescence GaN semiconductor laser and 750 nmn excitation light L22 by the drug fluorescence AlGaAs semiconductor laser are used.

  The imaging mode switching unit 390 includes a switching switch 391 that switches the imaging mode between the auto-fluorescence imaging mode and the drug fluorescence imaging mode according to an input from the observer, and a cable 392 that transmits a signal from the switching switch 391 to the control computer.

  The imaging unit 320 cuts the wavelength band of 420 nm or less that is the wavelength near the excitation light for autofluorescence and the wavelength band of 720 to 780 nm that is the wavelength near the excitation light for drug fluorescence from the fluorescence that has passed through the image fiber 303. Excitation light cut filter 321, a switch filter 322 in which two types of optical filters are combined, a filter rotating device 324 for rotating the switch filter 322, and a CCD image pickup device that captures a fluorescent image or the same-band reflected image transmitted through the switch filter 322 An imaging lens 325 that forms an image on 326, an A / D conversion circuit 327 that digitizes the fluorescence image and the same-band reflected image captured by the CCD image sensor 326, and an image signal that is digitized by the A / D conversion circuit 327 And an image memory 328 for storing.

  The image processing unit 340 includes an A / D converter 341 that performs A / D conversion on a normal image signal of a normal image captured by the CCD 307, a normal image memory 342 that stores a digitized normal image for each color, When displaying an image, the three-color image signal output in synchronization from the normal image memory 342 is converted into a video signal and output. When displaying a fluorescent image, the above-described synthesis is performed. A video signal processing circuit 343 that converts the composite image output from the image generation unit 320 into a video signal and outputs the video signal is provided.

  The composite image generation unit 330 includes a tissue property image generation unit 331 that generates a tissue property image based on the fluorescence correction image generated by the fluorescence correction image generation unit 351, and a reflection in the same band as the fluorescence stored in the fluorescence image memory 328. A tissue shape image generation unit 332 that generates a tissue shape image based on the image, and a composite image generation unit 333 that combines the tissue property image and the tissue shape image are provided.

  As shown in FIG. 6, the switching filter 322 includes an autofluorescence bandpass filter 323a that transmits light of 430 nm to 730 nm and a drug fluorescence bandpass filter 323b that transmits light of 780 to 900 nm. When the switching filter 322 is set to the autofluorescence imaging mode, the optical filter 323a is arranged on the optical path at the time of irradiation with the illumination light Lw and at the time of irradiation with the excitation light L21, and is set to the drug fluorescence imaging mode. In this case, the control computer 360 controls the optical filter 323b via the filter rotating device 324 so that the optical filter 323b is arranged on the optical path when the illumination light Lw and the excitation light L22 are irradiated. Other configurations are the same as those in the first and second embodiments.

  Next, the operation of this embodiment will be described.

In the fluorescence endoscope apparatus of the present embodiment, switching to the autofluorescence image capturing mode and the drug fluorescence image capturing mode is performed by an input from the observer to the image capturing mode switching switch 391. When the observer selects the auto fluorescence imaging mode, an auto fluorescence imaging mode signal is transmitted from the imaging mode changeover switch 391 to the control computer 360. The control computer 360 drives the white light source power supply 312 and the illumination light Lw is emitted from the white light source 311. The illumination light Lw is incident on the white light guide 301c via the white light condensing lens 313, guided to the distal end of the endoscope insertion portion, and then irradiated from the illumination lens 304 to the measurement target 50. The reflected light L 7 of the illumination light Lw is collected by the condenser lens 305, reflected by the prism 308, imaged on the CCD image sensor 307, and received by the CCD image sensor 307.

  Here, in the CCD image pickup element 307, a mosaic filter having an arrangement as shown in FIG. 7 is formed on-chip, and each of the reflected light L7 of the illumination light Lw transmits R light, G light, and B light. Filters 309a, 309b, and 306c to be arranged are arranged in a pattern as shown in the figure. The reflected light L7 formed on the mosaic filter is photoelectrically converted as an R light image, a G light image, and a B light image by the CCD image pickup device. The R, G, B, and image signals photoelectrically converted by the CCD image pickup device 307 are converted into digital signals by the A / D conversion circuit 3341, and the R image signal storage area and the G image signal storage in the normal image memory 342 are stored. It is stored in the storage area of the area and the B image signal. When the three-color image signals are stored in the normal image memory 342, they are output in synchronization with the display timing, converted into video signals by the video signal processing circuit 343, output to the monitor 361, and color. Displayed as an image. The above series of operations is controlled by the control computer 360. In this way, a normal image is displayed.

  When the imaging mode changeover switch 391 is operated and the autofluorescence mode is selected, the control computer 360 drives the changeover filter control means 324 so that the autofilter 323a is arranged on the optical path. Control. The reflected light L7 of the illumination light Lw when irradiated to the part to be measured 50 is also collected by the condenser lens 306, is incident on the tip of the image fiber 303, is collected by the lens 329 through the image fiber 303. The optical filter 323a of the switching filter 322 is transmitted, and only the component in the same wavelength band as the autofluorescence is transmitted.

  The reflected image having the same wavelength band as that of the autofluorescence is received by the CCD image pickup device 326, and an image signal of 500 × 500 pixels is obtained by acquiring an image signal for each pixel. The reflected image in the same band as the autofluorescence photoelectrically converted by the CCD image pickup device 326 is converted into a digital signal and then stored in the autofluorescence wavelength in-band reflected image storage area of the image memory 328.

  Next, an operation when an autofluorescence image is captured when the autofluorescence image capturing mode is set will be described. Based on the signal from the control computer 360, the self-fluorescent semiconductor laser power source 315 is driven, and the GaN-based semiconductor laser 314 emits excitation light L21 having a wavelength of 405 nm to 410 nm. The excitation light L21 passes through the excitation light condensing lens 316, enters the excitation light light guide 301a, is guided to the distal end of the endoscope insertion portion, and is irradiated from the illumination lens 304 to the measurement target 50. .

  The autofluorescence L31 from the measurement target 50 generated by irradiating the excitation light L21 is condensed by the condenser lens 306, is incident on the tip of the image fiber 303, is condensed by the lens 329 through the image fiber 303. Then, the light passes through the optical filter 323a of the switching filter 322 set by selecting the auto-fluorescence imaging mode with the imaging mode setting switch.

  The optical filter 323a is a band-pass filter that transmits light having a wavelength band of 430 nm to 730 nm, and the fluorescence transmitted through the optical filter 323a becomes an autofluorescence image.

  The autofluorescence image is received by the CCD image pickup device 325, subjected to photoelectric conversion, read by adding 5 × 5 pixel signals by binning readout, converted to a digital signal by the A / D conversion circuit 326, It is stored in the autofluorescence image storage area of the image memory 327. By performing binning readout as described above, it is possible to accurately capture a fluorescent image with low light intensity. However, the number of pixels of the fluorescence image is 100 × 100 pixels, which is 1/25 that of normal readout. Become.

  Next, the operation of generating a fluorescence correction image will be described. In the fluorescence correction image generation means 351, the autofluorescence image stored in the autofluorescence image storage area of the image memory 328 is the same as the autofluorescence stored in the autofluorescence wavelength same band reflection image storage area of the image memory 328. For each pixel, the pixel value in the autofluorescence image is divided by the pixel value in the reflection image in the same band for each pixel to generate a fluorescence correction image for the autofluorescence image.

  Subsequently, the tissue property image generation unit 331 of the composite image generation unit 330 uses the pixel values of the autofluorescence corrected image generated by the fluorescence correction image generation unit and the previously stored lookup table to use the Munsell table. A hue property H (Hue) in the color system is assigned to generate a tissue property image, which is output to the composite image generation means 333.

  Further, the tissue shape image generation unit 332 assigns the lightness V in the Munsell color system using the pixel value and the lookup table for each pixel of the reflection image stored in the reflection image storage area of the image memory 328. Then, a tissue shape image is generated and output to the composite image generation means 333.

  The composite image generation unit 333 converts the data of one pixel of the tissue characteristic image into data of 5 × 5 pixels, expands the number of pixels of the tissue characteristic image from 100 × 100 pixels to 500 × 500 pixels, and then Then, the tissue shape image and the tissue shape image based on the brightness V are combined to generate a combined image. When an image is displayed in color, the three attributes of color, hue, lightness, and saturation, are necessary. Therefore, in the image composition, each saturation S (Saturation) in the Munsell color system is Set the maximum value for each hue and brightness.

  Thereafter, RGB conversion is performed to generate a composite image, which is output to the video signal processing circuit 343.

  The composite image converted into the video signal by the video signal processing circuit 343 is input to the monitor 362 and displayed on the monitor 362 as a visible image. The above series of operations is controlled by the control computer 360.

  Due to the above-described operation, the hue of the displayed composite image reflects the autofluorescence intensity emitted from the measured unit 50, and the brightness is the pixel value of the same-band reflected image, that is, the measured unit 50. Therefore, information related to the shape of the measured part can be displayed on one image together with information related to the fluorescence emitted from the measured part 50, giving the viewer a sense of incongruity. There is nothing. Therefore, the observer can easily determine the tissue properties of the measured part.

  Next, an operation when the drug fluorescence imaging mode is selected will be described.

  When the observer selects the drug fluorescence imaging mode, a drug fluorescence imaging mode signal is transmitted from the imaging mode changeover switch 391 to the control computer 360. The control computer 360 drives the white light source power supply 312 and the illumination light Lw is emitted from the white light source 311. The normal image capturing and display using the illumination light Lw is the same as in the auto-fluorescent image capturing mode.

  Further, the control computer 360 drives the switching filter control means 324 to control the switching filter 322 so that the drug fluorescence filter 323b is arranged on the optical path. The reflected light L7 of the illumination light Lw when irradiated to the part to be measured 50 is also collected by the condenser lens 306, is incident on the tip of the image fiber 303, is collected by the lens 329 through the image fiber 303. The optical filter 323b of the switching filter 322 is transmitted, and only the component in the same wavelength band as the drug fluorescence is transmitted.

  The reflected image in the same wavelength band as the drug fluorescence is received by the CCD image sensor 326. The reflected image of the same band as the drug fluorescence photoelectrically converted by the CCD image pickup device 326 is converted into a digital signal and then stored in the drug fluorescence wavelength same band reflected image storage area of the image memory 328.

  Next, the action at the time of capturing a drug fluorescence image will be described. Based on the signal from the control computer 360, the drug fluorescence semiconductor laser power source 318 is driven, and the AlGaAs semiconductor laser 317 emits the excitation light L22 having a wavelength of 750 nm. The excitation light L22 passes through the excitation light condensing lens 319, enters the excitation light light guide 301b, is guided to the distal end of the endoscope insertion portion, and is irradiated from the illumination lens 304 to the measured portion 50. .

  The drug fluorescence L32 emitted from the fluorescence diagnostic drug inside the measurement target 50 generated by the irradiation with the excitation light L22 is collected by the condenser lens 306, is incident on the tip of the image fiber 303, and passes through the image fiber 303. The light is condensed by the lens 329 and passes through the optical filter 323 b of the switching filter 322.

  The optical filter 323b is a band-pass filter that transmits light having a wavelength band of 780 to 900 nm, and the fluorescence transmitted through the optical filter 323b becomes a drug fluorescence image.

  The drug fluorescence image is received by the CCD image sensor 326, subjected to photoelectric conversion, read by adding 5 × 5 pixel signals by binning readout, converted to a digital signal by the A / D conversion circuit 327, It is stored in the autofluorescence image storage area of the image memory 328. By performing binning readout as described above, it is possible to accurately capture a fluorescent image with low light intensity. However, the number of pixels of the fluorescence image is 100 × 100 pixels, which is 1/25 that of normal readout. Become.

  Next, the operation of generating a fluorescence correction image will be described. In the fluorescence correction image generation means 351, the drug fluorescence image data stored in the drug fluorescence image storage area of the image memory 328 is the same as the drug fluorescence stored in the drug fluorescence wavelength same-band reflection image storage area of the image memory 328. For each pixel, the pixel value in the drug fluorescence image is divided by the pixel value in the reflection image in the same band to generate a fluorescence correction image for the drug fluorescence image.

  The tissue property image generation unit 331 of the composite image generation unit 330 uses the pixel values of the drug fluorescence correction image generated by the fluorescence correction image generation unit and a pre-stored look-up table to use the hue in the Munsell color system. H (Hue) is assigned to generate a tissue property image and output to the composite image generation means 333. Further, the tissue shape image generation means 332 generates a tissue shape image by assigning the lightness V in the Munsell color system based on each pixel value of the reflection image in the same band as the drug fluorescence image and the lookup table, and generates a composite image. Output to the means 333. When an image is displayed in color, the three attributes of color, hue, lightness, and saturation, are necessary. Therefore, in the image composition, each saturation S (Saturation) in the Munsell color system is Set the maximum value for each hue and brightness.

  The composite image generation unit 333 generates a composite image by combining the tissue property image and the tissue shape image. Thereafter, RGB conversion is performed to generate a composite image, which is output to the video signal processing circuit 343. The composite image converted into the video signal by the video signal processing circuit 343 is input to the monitor 362 and displayed on the monitor 362 as a visible image. The above series of operations is controlled by the control computer 360.

  Due to the above-described operation, the hue of the displayed composite image reflects the drug fluorescence intensity emitted from the measured unit 50, and the brightness is the pixel value of the same-band reflected image, that is, the measured unit 50. Therefore, information related to the shape of the measured part can be displayed on one image together with information related to the fluorescence emitted from the measured part 50, giving the viewer a sense of incongruity. There is nothing.

  In the present embodiment, the tissue shape image generating unit 332 generates a tissue shape image by assigning the brightness V in the Munsell color system to each pixel of the fluorescence wavelength same-band reflected image. It may be obtained separately and a tissue shape image may be generated based on this reflection image.

  In addition, with the configuration of the fluorescence endoscope apparatus of the present embodiment, it is possible to select and image autofluorescence imaging and drug fluorescence imaging in accordance with a patient's medical condition with a single apparatus.

  In the present embodiment, the auto fluorescence imaging mode and the drug fluorescence imaging mode are switched between the imaging modes by the mode changeover switch. However, the normal light image, the auto fluorescence image, and the drug fluorescence image are sequentially captured and simultaneously displayed. Also good. In this case, the illumination light is emitted in the first 1/90 seconds, the reflected light image is picked up by the CCD image sensor 307, and the autofluorescence generated by irradiating the excitation light for autofluorescence in the next 1/90 seconds is rotated. The filter 322 passes through 323a and is imaged by the CCD image sensor 326. In the next 1/90 seconds, the drug fluorescence generated by irradiating the excitation light for drug fluorescence is transmitted through the rotary filter 322 323b and imaged by the CCD image sensor 326. In addition, by converting the image data into image data and inputting the image data to the video signal processing circuit 343 while taking different images, the three images can be simultaneously displayed at the video rate on the display means. In this case, the rotation filter 322 is controlled by the control computer so that 323a is arranged on the optical path during autofluorescence imaging and 323b is arranged on the optical path during drug fluorescence imaging. It should be noted that the rotation filter is arranged such that 323a is arranged on the optical path for the first 1/180 second and 323b is arranged on the optical path for the next 1/180 second among the 1/90 seconds irradiated with the illumination light. 322 is controlled and imaged by a CCD imaging device, and an autofluorescence wavelength in-band reflection image and a drug fluorescence wavelength in-band reflection image are acquired respectively.

  In Embodiments 2 and 3, since the fluorescent image is read by binning readout when imaged, the number of pixels of the fluorescent image is 100 × 100 pixels. However, when the composite image is generated, the tissue property image Is converted into data of 5 × 5 pixels, and the number of pixels of the tissue characteristic image is expanded from 100 × 100 pixels to 500 × 500 pixels. Since the composite image is generated by synthesizing the tissue shape images based on the display image, the number of pixels of the display image corresponds to 500 × 500 pixels, and the shape of the measurement target can be clearly displayed.

  In the first and third embodiments, the illumination light is irradiated onto the subject and the reflected light is imaged through the mosaic filter when capturing the normal image. However, the R light, G light, B light, and IR are used. You may image light as light sequentially. In that case, a rotating filter having a filter that transmits R light, G light, B light, and IR light may be arranged before entering the light guide from the white light source, and irradiation light to the subject may be sequentially used as light, or A similar rotary filter may be arranged and sequentially imaged before the subject is irradiated with white light and the reflected light is received by the imaging device.

  Moreover, since the GaN-based semiconductor laser is used as the excitation light source for autofluorescence, the excitation light can be emitted from an inexpensive and small light source. In addition, since the wavelength of the excitation light is set to 405 nm to 410 nm, fluorescence is efficiently emitted from the measured part 50.

  Further, in Embodiments 1 and 3, an infrared fluorescent contrast agent containing a sodium salt in which three or more sulfonic acid groups are introduced into a cyanine dye compound emitting fluorescence in the wavelength region of 750 nm to 900 nm was used as a fluorescent diagnostic agent. The present invention is not limited to this, and other drugs may be used. In this case, the wavelength for obtaining the excitation light, the fluorescence image and the wavelength for obtaining the reflection image in the same band can be appropriately selected according to the fluorescent diagnostic agent.

  In each embodiment, a charge-multiplier type CCD (CMD (Charge Multiplying Detector) -CCD) may be used as the CCD image pickup device. In this case, a sufficient fluorescence image is obtained even for low intensity fluorescence. Can be acquired.

1 is a block diagram showing a configuration of a fluorescence endoscope apparatus according to a first embodiment of the present invention. The figure which shows the mosaic filter used with the fluorescence endoscope which concerns on the 1st Embodiment of this invention The block diagram which shows the structure of the fluorescence endoscope apparatus which concerns on the 2nd Embodiment of this invention. The figure which shows the switching filter used with the fluorescence endoscope which concerns on the 2nd Embodiment of this invention. The block diagram which shows the structure of the fluorescence endoscope apparatus which concerns on the 3rd Embodiment of this invention. The figure which shows the switching filter used with the fluorescence endoscope which concerns on the 3rd Embodiment of this invention. The figure which shows the mosaic filter used with the fluorescence endoscope which concerns on the 3rd Embodiment of this invention. Illustration of the spectral characteristics of autofluorescence emitted from normal and diseased tissues

Explanation of symbols

50 Measurement unit 100, 200, 300 Endoscope insertion unit 106, 309 Mosaic filter 107, 207, 307, 226, 326 CCD image sensor 183 Fluorescence corrected image / tissue property image generation means 184, 233, 333 Composite image generation means 185, 232, 332 Tissue shape image generation means 222, 322 Switching filter 231 Fluorescence calculation image / tissue property image generation means 250 Fluorescence correction image generation unit 251 Narrow band fluorescence correction image generation means 252 Broadband fluorescence correction image generation means 331 Tissue property image Generation means 351 Fluorescence correction image generation means L1 White light L4, L7 Reflected light L21, L22 Excitation light L31 Autofluorescence L32 Drug fluorescence Lw Illumination light

Claims (12)

Fluorescence image capturing means for capturing a fluorescence image based on the intensity of fluorescence in a predetermined wavelength band among the fluorescence generated from the measured portion by irradiating the measured portion with excitation light;
Reflected image imaging means for imaging a reflected image based on the intensity of the reflected light in the predetermined wavelength band among the reflected light reflected from the measurement target portion by irradiating the reference light including the predetermined wavelength band;
Fluorescence correction image generation means for performing a calculation based on the fluorescence image and the reflection image and outputting a fluorescence correction image in which the intensity of fluorescence in the predetermined wavelength band depending on the wavelength is corrected is provided. Fluorescence imaging device.   The fluorescence image capturing apparatus according to claim 1, further comprising a tissue property image generating unit that assigns color information to the fluorescence correction image and generates a tissue property image representing the tissue property of the measurement target.   The fluorescence image capturing apparatus according to claim 1, further comprising a tissue shape image generating unit that assigns luminance information to the reflected image and generates a tissue shape image representing a tissue shape of the measurement target. Tissue shape image generating means for assigning luminance information to the reflected image and generating a tissue shape image representing a tissue shape of the measurement target part;
The fluorescence image capturing apparatus according to claim 2, further comprising a composite image generation unit configured to combine the tissue property image and the tissue shape image to generate a composite image.   5. The fluorescence image capturing apparatus according to claim 1, wherein the calculation based on the fluorescence image and the reflection image by the fluorescence correction image generation unit is a division of the fluorescence image and the reflection image. 6. . A first fluorescence image capturing means for capturing a first fluorescence image based on the intensity of fluorescence in a first wavelength band among the fluorescence generated from the measured portion by irradiating the measured portion with excitation light;
The first reflected image based on the intensity of the reflected light in the first wavelength band among the reflected light reflected from the measurement target portion by irradiating the first reference light including the first wavelength band. First reflected image imaging means for imaging;
A second fluorescence image capturing means for capturing a second fluorescence image based on the intensity of fluorescence in a second wavelength band different from the first wavelength band among the fluorescence generated from the measurement target;
A second reflected image based on the intensity of the reflected light in the second wavelength band among the reflected light reflected from the measurement target portion by irradiating the second reference light including the second wavelength band. First fluorescence obtained by performing calculation based on the second reflected image imaging means for imaging, the first fluorescence image and the first reflected image, and correcting the fluorescence intensity in the first wavelength band depending on the wavelength First fluorescence corrected image generation means for outputting a corrected image;
Second fluorescence correction that performs a calculation based on the second fluorescence image and the second reflection image, and outputs a second fluorescence correction image in which the intensity of fluorescence in the second wavelength band depending on the wavelength is corrected. Image generating means;
A fluorescence image capturing apparatus, comprising: a fluorescence calculation image generation unit that performs a calculation based on the first fluorescence correction image and the second fluorescence correction image to generate a fluorescence calculation image.   The fluorescence image capturing apparatus according to claim 6, further comprising a tissue property image generating unit that assigns color information to the fluorescence calculation image and generates a tissue property image representing the tissue property of the measurement target.   The fluorescence according to claim 6, further comprising tissue shape image generation means for assigning luminance information to the first or second reflected image and generating a tissue shape image representing the tissue shape of the measurement target. Imaging device. Tissue shape image generation means for assigning luminance information to the first or second reflected image and generating a tissue shape image representing the tissue shape of the measurement target;
The fluorescence image capturing apparatus according to claim 7, further comprising a composite image generation unit configured to combine the tissue property image and the tissue shape image to generate a composite image. The calculation based on the first fluorescence image and the first reflection image by the first fluorescence correction image generation means is a division of the first fluorescence image and the first reflection image,
The calculation based on the second fluorescence image and the second reflection image by the second fluorescence correction image generation means is a division of the second fluorescence image and the second reflection image. Item 10. The fluorescent image capturing device according to any one of Items 6 to 9.   11. The fluorescence calculation image generation unit generates the normalized fluorescence calculation image by dividing the first fluorescence correction image by the second fluorescence correction image. The fluorescence image imaging device according to any one of the preceding claims.   The fluorescent image capturing apparatus according to claim 1, wherein the fluorescent image capturing apparatus is in the form of an endoscope that is inserted into a living body through a hole in the living body.

Images