JP3881143B2 - Fluorescence display method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluorescence display method and apparatus for irradiating an observation part of a living body with excitation light and displaying information according to the characteristics of autofluorescence emitted from a living body dye.
[0002]
[Prior art]
Conventionally, when the living body is irradiated with excitation light in the excitation wavelength region of the in vivo dye, the fluorescence intensity emitted differs between normal tissue and diseased tissue. There has been proposed a technique for displaying the localization / infiltration range of a diseased tissue as a fluorescence image by irradiating and receiving fluorescence emitted from a living body dye.
[0003]
Usually, when excitation light is irradiated, strong fluorescence is emitted from normal tissues and weak fluorescence is emitted from lesion tissues. Therefore, the lesion state can be determined by measuring the fluorescence intensity.
[0004]
This type of fluorescent display device basically includes an excitation light irradiating means for irradiating the living body with excitation light in the excitation wavelength region of the living body dye, and a fluorescence image of the living body by detecting the fluorescence emitted by the living body dye. An imaging means for imaging and an image display means for receiving the output of the imaging means and displaying the fluorescent image, and in many cases, an endoscope, a colposcope, or a surgical instrument inserted into a body cavity It is configured in a shape incorporated in a microscope or the like.
[0005]
By the way, in the fluorescent display device as described above, the distance from the excitation light irradiation system to the living body observation part is not uniform due to the unevenness of the part of the living body, and the excitation light illuminance in the excitation light irradiation part of the living body is generally non-uniform. is there. The fluorescence intensity is approximately proportional to the excitation light illuminance, and the excitation light illuminance decreases in inverse proportion to the square of the distance. Therefore, the lesion tissue nearer than the normal tissue far from the light source emits stronger fluorescence, or the fluorescence from the normal tissue at a position inclined with respect to the excitation light is extremely reduced. When the illuminance of the excitation light is not uniform in this way, the fluorescence intensity changes according to the level of the illuminance of the excitation light, so that the lesion state may be erroneously determined.
[0006]
On the other hand, in the apparatus shown in "FLUORESCENCE IMAGING OF EARLY LUNG CANCER" (Annual International Conference of the IEEE Engineering and Biology Society, Vol.12, No.3, 1990) The fluorescence generated from the living body dye is separated into the intensity of the green wavelength band (hereinafter referred to as green band intensity G) and the intensity of the red wavelength band (hereinafter referred to as red band intensity R). An image calculation based on the division between the intensity R and the green band intensity G is performed, and the division result is displayed. This is because the fluorescence spectrum is different between normal tissue and diseased tissue, that is, the fluorescence spectrum emitted by the in-vivo dye in the normal tissue part, the intensity of the green band is particularly low in the diseased tissue compared to the normal tissue. Therefore, in the diseased tissue, the fact that the decrease rate of the green band intensity G of fluorescence is much larger than the decrease rate of the red band intensity R is used, and the fluorescence from the lesion tissue is specifically determined by the division of R / G. Can be extracted and displayed as an image.
[0007]
That is, the division of R / G cancels the fluorescence intensity term depending on the distance between the excitation light source and the fluorescence light receiving part and the living body observation part, and a display reflecting only the difference in the shape of the fluorescence spectrum is obtained.
[0008]
[Problems to be solved by the invention]
However, conventionally, there has been a problem that a sufficient combination of detection wavelengths in which the difference in the shape of the fluorescence spectrum emitted from the normal tissue and the lesioned tissue appears remarkably is not performed, and a desirable combination of detection wavelengths is not presented as a numerical value. there were.
[0009]
In view of the above problems, the present invention examines a combination of detection wavelengths in which the difference in the shape of the fluorescence spectrum emitted from normal tissue and lesion tissue appears prominently, and extracts fluorescence at two appropriate detection wavelengths for which numerical values are presented. It is an object of the present invention to provide a fluorescent display device with improved reliability for detecting light intensity and displaying information according to the ratio between the two.
[0010]
[Means for Solving the Problems]
The fluorescence display method according to the present invention includes a light intensity in a predetermined wavelength band including 480 nm and 630 nm or 700 nm, in which a difference in spectral shape is noticeable from fluorescence emitted from a measurement unit of a living body irradiated with excitation light. The light intensity in a predetermined wavelength band is detected, and information corresponding to the ratio between the two is displayed.
[0011]
In addition, the fluorescent display device according to the present invention includes an excitation light irradiating unit that irradiates a living body measurement unit with excitation light,
First fluorescence intensity detection means for detecting light intensity in a predetermined wavelength band including 480 nm from fluorescence emitted from the measurement unit by irradiation of the excitation light;
Second fluorescence intensity detection means for detecting light intensity in a predetermined wavelength band including 630 nm or 700 nm from fluorescence emitted from the measurement unit;
And a display means for displaying information according to a ratio between the light intensity detected by the first fluorescence intensity detection means and the light intensity detected by the second fluorescence intensity detection means. It is.
[0012]
In the fluorescence display device, the first fluorescence intensity detection unit selects a fluorescence having a predetermined wavelength band including 480 nm from fluorescence emitted from the measurement unit by irradiation with the excitation light. A selection means, and a first light intensity detection means for detecting the light intensity of the fluorescence selected by the first wavelength selection means,
Second wavelength selection means for selecting fluorescence of a predetermined wavelength band including 630 nm or 700 nm from the fluorescence emitted from the measurement unit by the second fluorescence intensity detection means by irradiation of the excitation light; The second light intensity detecting means for detecting the light intensity of the fluorescence selected by the wavelength selecting means is desirable.
[0013]
The predetermined wavelength band selected by the first wavelength selection means is 480 nm ± 70 nm or less, and the predetermined wavelength band selected by the second wavelength selection means is 630 nm ± 70 nm or less or 700 nm ± 70 nm or less. It is preferable that
[0014]
Further, in the fluorescent display device according to the present invention, it is desirable to use light having a wavelength of 380 nm to 420 nm that is out of the characteristic light intensity peak of normal tissue as excitation light. As the excitation light irradiation means, a GaN-based semiconductor laser is suitable.
[0015]
The fluorescent display device described above can be applied to a device that detects a fluorescent image two-dimensionally or a device that detects the fluorescence intensity for each point of a living body part.
[0016]
As the wavelength selection means, for example, a desired wavelength band may be cut out by a dichroic mirror or the like, or a desired wavelength band may be cut out in a time division manner by switching an optical filter or the like. If the fluorescent image is to be detected two-dimensionally, the wavelength selection means may be one that cuts out a desired wavelength band by using a mosaic filter in which optical filters are connected in a mosaic shape, that is, a desired wavelength range. Anything can be selected.
[0017]
The display means may use any display method, for example, by detecting the light intensity in a predetermined wavelength band including 480 nm and the light intensity in a predetermined wavelength band including 630 nm or 700 nm, and monitoring the ratio between them. Or a method of displaying on a printer or the like, or a method of changing the hue or luminance of the display color according to the ratio of the light intensity, and the type is not limited.
[0018]
【The invention's effect】
When the living tissue is irradiated with excitation light, the living tissue emits fluorescence having a spectrum shown in FIG. This fluorescence is presumed to be superimposed with fluorescence from various in vivo pigments such as FAD, collagen, fibronectin, and porphyrin. FIG. 5 shows representative fluorescence spectra of fluorescence emitted from normal tissue and fluorescence emitted from diseased tissue measured by the inventors.
[0019]
The normal tissue portion and the diseased tissue have different fluorescence spectrum sizes and shapes, and the normal tissue has a large fluorescence overall, but the lesion tissue has an overall decrease in fluorescence. The normal tissue has a spectrum intensity peak in the vicinity of 480 nm, which is the blue band, and the lesion tissue has a spectrum intensity peak in the vicinity of 630 nm and 700 nm, which is the red band.
[0020]
FIG. 6 shows a fluorescence spectrum intensity ratio distribution in which the intensity ratio for each wavelength when the fluorescence intensity of the entire measurement bandwidth is set to 1 from each fluorescence spectrum. In the spectral intensity ratio distribution, the difference in the spectral shape of the fluorescence emitted from the normal tissue and the fluorescence emitted from the diseased tissue is shown more clearly.
[0021]
From these figures, the inventors examined the combination of detection wavelengths in which the difference in the shape of the fluorescence spectrum emitted from the normal tissue and the diseased tissue appears remarkably.
[0022]
As a result, when the light intensity ratio in the band near 480 nm and the light intensity near 630 nm or 700 nm were detected, it became clear that the ratio markedly represents the difference in fluorescence spectrum shape between normal tissue and lesion tissue. .
[0023]
That is, from the fluorescence detected from the measurement part whose tissue characteristics are unknown, the light intensity in a predetermined wavelength band including 480 nm where the characteristic light intensity increases in the normal tissue and the light intensity characteristically increases in the lesion tissue 630 nm. Alternatively, by detecting the light intensity in a predetermined wavelength band including 700 nm and displaying information according to the ratio, the observer can infer from the display whether the measurement site is normal tissue or lesion tissue. It becomes.
[0024]
From the above examination results, according to the fluorescent display device according to the present invention, the light intensity in the predetermined wavelength band including 480 nm and the predetermined wavelength band including 630 nm or 700 nm is calculated from the fluorescence emitted from the measurement unit by the irradiation of excitation light. By detecting and displaying information corresponding to the ratio between the two, information with improved reliability can be displayed.
[0025]
In addition, the detection of the light intensity in the predetermined wavelength band includes first wavelength selection means for selecting fluorescence in a predetermined wavelength band including 480 nm from fluorescence emitted from the measurement unit by irradiation of excitation light, A first light intensity detecting means for detecting the fluorescence intensity of the fluorescence selected by the first wavelength selecting means, and a first light intensity detecting means for selecting fluorescence in a predetermined wavelength band including 630 nm or 700 nm from the fluorescence emitted from the measurement unit. By using the second wavelength selecting means and the second light intensity detecting means for detecting the light intensity of the fluorescence selected by the second wavelength selecting means, it can be easily detected.
[0026]
Further, from the results of the fluorescence spectrum analysis illustrated in FIG. 5 and FIG. 6, when the bandwidth of each wavelength band exceeds ± 70 nm, it is detected from the lesion tissue for the light intensity of the predetermined bandwidth detected from the normal tissue in the vicinity of 480 nm. The ratio of the light intensity of the predetermined bandwidth increased, and in the wavelength band near 630 nm or 700 nm, the ratio of the light intensity of the predetermined bandwidth detected from the lesioned tissue to the light intensity of the predetermined bandwidth detected from the normal tissue May decrease. Therefore, the predetermined wavelength band selected by the first wavelength selection means is 480 nm ± 70 nm or less, and the predetermined wavelength band selected by the second wavelength selection means is 630 nm ± 70 nm or less or 700 nm ± 70 nm or less. Then, it became clear that the ratio of the light intensity having the desired reliability can be obtained.
[0027]
In addition, by using excitation light having a wavelength of 380 nm to 420 nm that deviates from the vicinity of 480 nm, which is characteristically increased in fluorescence emitted from normal tissue, fluorescence having a desired waveform of fluorescence spectrum is emitted and displayed. The reliability of is improved. Further, by using a GaN semiconductor laser as the excitation light irradiation means, it is possible to reduce the size and cost of the apparatus.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, an endoscope apparatus, which is a first specific embodiment to which a fluorescent display device according to the present invention is applied, will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic configuration diagram of an endoscope apparatus to which a fluorescent display device according to the present invention is applied. The biometric measurement unit is irradiated with excitation light, and fluorescence emitted from the measurement unit is two-dimensionally detected by an image fiber. Then, the light is received by the high-sensitivity imaging device, the light intensity B in the wavelength band 480 nm ± 70 nm and the light intensity R in the wavelength band 630 nm ± 70 nm are detected, R / B is calculated and displayed.
[0029]
The endoscope apparatus according to the first embodiment of the present invention includes an endoscope 100 inserted into a site suspected of being a patient's lesion, and a light source that emits white light for normal image observation and excitation light for fluorescence measurement. The illumination unit 110 receives fluorescence generated from the living body measurement unit by the excitation light during fluorescence display, and calculates an R / B. An R / B calculation unit 120 calculates a reference value stored in advance and the calculated R / B. The comparison unit 130 that compares and outputs a signal according to the comparison result, the image processing unit 140 that performs image processing for displaying the normal image and the comparison result as a visible image, and is connected to each unit to control the operation timing. The controller 150 includes a monitor 170 that displays normal image information processed by the image processing unit 140 as a visible image, and a monitor 180 that displays a comparison result.
[0030]
The endoscope 100 includes a light guide 101, a CCD cable 102, and an image fiber 103 that extend to the tip. An illumination lens 104 and an objective lens 105 are provided at the distal ends of the light guide 101 and the CCD cable 102, that is, at the distal end of the endoscope 100. Further, the image fiber 103 is a quartz glass fiber, and a condensing lens 106 is provided at the tip thereof. A CCD image sensor 107 is connected to the tip of the CCD cable 102, and a mirror 108 is attached to the CCD image sensor 107. The light guide 101 is a bundle of a white light light guide 101a, which is a multi-component glass fiber, and an excitation light light guide 101b, which is a quartz glass fiber, and is integrated into a cable shape. The white light light guide 101a and the excitation light light guide are integrated. 101b is connected to the lighting unit 110. One end of the CCD cable 102 is connected to the image processing unit 140, and one end of the image fiber 103 is connected to the R / B calculation unit 120.
[0031]
The illumination unit 110 includes a white light source 111 that emits white light L1 for normal image observation, a white light source power supply 112 that is electrically connected to the white light source 111, and a GaN-based semiconductor laser 114 that emits excitation light L2 for fluorescence observation. And a semiconductor laser power source 115 electrically connected to the GaN-based semiconductor laser 114.
[0032]
The R / B calculation unit 120 includes an excitation light cut filter 121 that cuts the wavelength in the vicinity of the excitation light from the fluorescence L3 that has passed through the image fiber 103, and a mosaic filter 123 in which two types of optical filters are combined on the mosaic. CCD image sensor 125, A / D conversion circuit 126 for digitizing the fluorescence signal received by the CCD image sensor 125, fluorescence image memory 127 for storing the fluorescence image, R / B from the values stored in the fluorescence image memory 127 An R / B calculation unit 128 is provided.
[0033]
The mosaic filter 123 is composed of two types of optical filters 124a and 124b as shown in FIG. 2. The optical filter 124a is a bandpass filter that transmits light of 480 nm ± 70 nm, and the optical filter 124b is 630 nm ± 70 nm. It is a band pass filter that transmits light.
[0034]
The comparison unit 130 compares the storage unit 131 in which the reference value RE is stored with the R / B calculated by the R / B calculation unit 127 and the reference value RE stored in the storage unit 131. It has.
[0035]
The reference value RE is a value set in advance based on R / B calculated from a living tissue that is clearly a normal tissue or a diseased tissue.
[0036]
The image processing unit 140 is output from the A / D conversion circuit 141 for digitizing the video signal obtained by the CCD image sensor 107, the normal image memory 142 for storing the digitized normal image signal, and the normal image memory 142. The video signal processing circuit 143 converts the image signal and the comparison result of the comparison unit 132 into a video signal.
[0037]
The operation of the endoscope apparatus having the above configuration to which the fluorescent display device according to the present invention is applied will be described below. First, the operation of the endoscope apparatus during normal image observation will be described.
[0038]
During normal observation, the white light source power source 112 is driven based on a signal from the controller 150, and white light L1 is emitted from the white light source 111. The white light L1 enters the white light guide 101a through the lens 113, is guided to the distal end portion of the endoscope, and is irradiated from the illumination lens 104 to the measurement unit 22.
[0039]
The reflected light of the white light L1 is collected by the objective lens 105, reflected by the mirror 108, and imaged on the CCD image sensor 107. The video signal from the CCD image sensor 107 is input to the A / D conversion circuit 141, digitized, and stored in the normal image memory 142. The normal image signal stored in the normal image memory 142 is input to the monitor 170 after DA conversion by the video signal generation circuit 143, and is displayed on the monitor 170 as a visible image. The above series of operations is controlled by the controller 150.
[0040]
Next, the operation when displaying a fluorescent image will be described. Based on the signal from the controller 150, the excitation light source power source 115 is driven, and the excitation light L2 having a wavelength of 410 nm is emitted from the GaN-based semiconductor laser 114. The excitation light L2 passes through the lens 116, enters the excitation light light guide 101b, is guided to the distal end portion of the endoscope, and is irradiated from the illumination lens 104 to the measurement unit 22.
[0041]
Fluorescence L3 from the measurement unit 22 generated by irradiating the excitation light L2 is condensed by the condenser lens 106, is incident on the tip of the image fiber 103, and is incident on the excitation light cut filter 121 via the image fiber 103. To do.
[0042]
The fluorescence L3 collected by the lens 122 passes through the mosaic filter 123 on-chip on the CCD image sensor 125, and is received by the CCD image sensor 125. The video signal from the CCD image sensor 125 is converted into an A / D conversion circuit 126. And is converted into digital data and stored in the fluorescence image memory 127.
[0043]
At this time, in the fluorescence image memory 127, the fluorescent video signals transmitted through the optical filters of the mosaic filter 123 are stored in different areas. Accordingly, fluorescence data in the wavelength band 480 nm ± 70 nm and fluorescence data in the wavelength band 630 nm ± 70 nm are alternately stored.
[0044]
The R / B calculation unit 128 calculates R / B for each area using data stored in adjacent areas of the fluorescence image memory 127.
[0045]
The comparison unit 132 compares the R / B of each area calculated by the R / B calculation unit 128 with the reference value RE stored in the storage unit 131.
[0046]
The comparison result is displayed on the monitor 180 as an image. By changing the display color of the measured area between when R / B is less than or equal to the reference value RE and when R / B is greater than the reference value RE, the measurer can instantly recognize the comparison result. Become.
[0047]
Further, the comparison may be performed not for each pixel but for each pixel corresponding to the binning process of the CCD image sensor 125, or for each pixel region in an arbitrary range desired by the measurer. . Alternatively, it is possible to compare only the region designated by the measurer, or to perform comparison by thinning out pixels as appropriate.
[0048]
When there is an area where comparison processing is not performed, the comparison area can be clearly displayed by displaying the display color of the area in a predetermined color. When the comparison pixel is thinned out, complementary display is performed based on the comparison result in the vicinity.
[0049]
As described above, a wavelength band of 480 nm ± 70 nm and a wavelength band of 630 nm ± 70 nm are cut out from the fluorescence emitted from the measurement part by irradiation with excitation light, and the ratio R / B of the light intensity is compared with the reference value RE. Then, by displaying the comparison result, information with improved reliability can be displayed.
[0050]
In addition, by using a GaN-based semiconductor laser having a wavelength of 410 nm as the excitation light irradiation means, it is possible to reduce the size and cost of the apparatus without hindering the detection of light intensity.
[0051]
In addition to the optical filter 124a that transmits a wavelength of 480 nm ± 70 nm and the optical filter 124b that transmits a wavelength band of 630 nm ± 70 nm as shown in FIG. The CCD image sensor 125 can be used for both normal image detection and fluorescence detection.
[0052]
In addition, if a CCD image sensor on which the above mosaic filter is on-chip is disposed at the endoscope tip, it can be used for both normal image detection and fluorescence detection.
[0053]
Further, in this apparatus, the comparison is made to display whether the ratio of the light intensity is larger or smaller than the reference value RE, but the light intensities in the two detected wavelength bands can be displayed without performing such a comparison. It is also possible to display the ratio obtained by dividing the number as it is, or display each light intensity by the additive color mixing method, and express the light intensity ratio as a change in the hue of the display screen.
[0054]
Next, with reference to FIGS. 3 and 4, an endoscope apparatus as a second specific embodiment to which the fluorescent display device according to the present invention is applied will be described. FIG. 3 is a schematic configuration diagram of an endoscope apparatus to which the fluorescence display device according to the present invention is applied. By irradiating the living body measuring section with excitation light and detecting the fluorescence generated thereby by the quartz fiber, The light intensity B ′ in the wavelength band 480 nm ± 30 nm and the light intensity R ′ in the wavelength band 630 nm ± 30 nm are detected from the fluorescence emitted from one point, and R ′ / B ′ is calculated and displayed.
[0055]
An endoscope apparatus according to an embodiment of the present invention includes an endoscope 200 that is inserted into a site suspected of being a patient's lesion, an illumination unit 210 that includes a white light for normal image observation and a light source that emits excitation light for fluorescence measurement. An optical path separation unit 220 that separates the optical path of the measured fluorescence from the excitation light, and an R ′ / B ′ calculation unit 230 that receives fluorescence generated from the biological measurement unit by the excitation light during fluorescence display and calculates R ′ / B ′. A comparison unit 240 that compares a pre-stored reference value with the calculated R ′ / B ′ and outputs a signal corresponding to the comparison result; an image for displaying a normal image and a comparison result as a visible image An image processing unit 250 that performs processing, a controller 260 that is connected to each unit and controls operation timing, a monitor 170 that displays normal image information processed by the image processing unit 250 as a visible image, and a comparison result Nita 180, and the excitation light and fluorescence are made of quartz fiber 290 for guiding.
[0056]
The endoscope 200 includes a force guide port 203 through which a light guide 201 extending to the tip, a CCD cable 202, and a quartz fiber 290 pass. An illumination lens 204 and an objective lens 205 are provided at the distal ends of the light guide 201 and the CCD cable 202, that is, at the distal end of the endoscope 200. A CCD image pickup element 206 is connected to the tip of the CCD cable 202, and a mirror 207 is attached to the CCD image pickup element 206. One end of the light guide 201 is connected to the illumination unit 210, and one end of the CCD cable 202 is connected to the image processing unit 250.
[0057]
The illumination unit 210 includes a white light source 211 that emits white light L4 for normal image observation, a white light source power supply 212 that is electrically connected to the white light source 211, and GaN as an excitation light source that emits excitation light L5 for fluorescence observation. A semiconductor laser 214 and a semiconductor laser power source 215 electrically connected to the GaN semiconductor laser 214.
[0058]
The optical path separation unit 220 causes the excitation light L5 output from the GaN-based semiconductor laser 214 to enter the silica fiber 290, and conversely, transmits the fluorescence L6 passing through the silica fiber 290 to the temporary principal component score calculation unit 230. 221 is provided.
[0059]
The R ′ / B ′ calculation unit 230 cuts out a desired wavelength band from the excitation light cut filter 231 that cuts the wavelength in the vicinity of the excitation light from the fluorescence L6 that has passed through the quartz fiber 290, and the fluorescence L6 that has passed through the excitation light cut filter 231. A switching filter 233, a filter rotating device 235 for rotating the switching filter 233, a photodetector 236 for measuring the light intensity of the fluorescence transmitted through the switching filter 233, and measurement data for storing the measurement data stored in the photodetector 236 An R ′ / B ′ calculating unit 238 for calculating R ′ / B ′ from values stored in the memory 237 and the measurement data memory 237 is provided.
[0060]
The switching filter 233 is composed of two types of optical filters 234a and 234b as shown in FIG. 4. The optical filter 234a is a bandpass filter that transmits light of 480 nm ± 30 nm, and the optical filter 234b is 630 nm ± 30 nm. It is a band pass filter that transmits light.
[0061]
The comparison unit 240 includes a storage unit 241 in which the reference value RE ′ is stored, R ′ / B ′ calculated by the R ′ / B ′ calculation unit 237, and a reference value RE ′ stored in the storage unit 241. A comparison unit 242 for comparing the two.
[0062]
The reference value RE ′ is set based on R ′ / B ′ obtained from a biological tissue previously recognized as a normal tissue or a diseased tissue, and stored in the storage unit 241.
[0063]
The image processing unit 250 is output from the A / D conversion circuit 251 for digitizing the video signal obtained by the CCD image sensor 206, the normal image memory 252 for storing the digitized normal image signal, and the normal image memory 252. And a video signal processing circuit 253 for converting the comparison result of the image signal and the comparison unit 242 into a video signal.
[0064]
The operation of the endoscope apparatus having the above configuration to which the fluorescent display device according to the present invention is applied will be described below. First, the operation of the endoscope apparatus during normal image observation will be described. During normal observation, the white light source power source 212 is driven based on a signal from the controller 260, and white light L4 is emitted from the white light source 211. The white light L4 enters the light guide 201 through the lens 213, is guided to the distal end portion of the endoscope, and is irradiated from the illumination lens 204 to the observation unit 20 including the measurement unit 11.
[0065]
The reflected light of the white light L4 is condensed by the objective lens 205, reflected by the mirror 207 at a right angle, and imaged on the CCD image pickup device 206. The video signal from the CCD image sensor 206 is input to the A / D conversion circuit 251, digitized, and stored in the normal image memory 252. The normal image signal stored in the normal image memory 252 is input to the monitor 270 after DA conversion by the video signal generation circuit 253 and is displayed on the monitor 270 as a visible image. The above series of operations is controlled by the controller 260.
[0066]
Next, the operation at the time of displaying fluorescence information will be described. Based on the signal from the controller 260, the excitation light source power source 215 is driven and the GaN-based semiconductor laser 214 emits excitation light L5 having a wavelength of 410 nm. The excitation light L5 passes through the lens 216 and travels toward the dichroic mirror 221. The excitation light L5 reflected by the dichroic mirror 221 is incident on the quartz fiber 290 by the lens 222, guided through the forceps port 203 of the endoscope, to the vicinity of the measurement unit 11, and from the tip of the quartz fiber 290 to the measurement unit 11 Is irradiated.
[0067]
Fluorescence L6 from the measurement unit 11 generated by irradiating the excitation light L5 is incident on the tip of the quartz fiber 290 and travels to the dichroic mirror 221 through the quartz fiber 290 and the lens 222. The dichroic mirror 221 has a structure that allows light incident from the left side in the figure to pass therethrough. The fluorescence L6 that has passed through the dichroic mirror 221 passes through the excitation light cut filter 231 and the lens 232, and enters the switching filter 233. The excitation light cut filter 231 is a long pass filter that transmits all fluorescence having a wavelength of 420 nm or more. Since the wavelength of the excitation light L5 is 410 nm, the excitation light L5 reflected by the measurement unit 11 is cut by the excitation light cut filter 231 and does not enter the switching filter 233.
[0068]
Under the control of the controller 260, the filter rotating device 235 is driven, and the fluorescence L6 sequentially passes through the optical filter 234a or 234b and then enters the photodetector 236, and the light intensity is detected. At the same time, in the measurement data memory 237, under the control of the controller 260, the fluorescence light intensity B ′ transmitted through the optical filter 234a is stored in a predetermined area in the measurement data memory 237, and the fluorescence light transmitted through the optical filter 234b. The intensity R ′ is stored in different areas.
[0069]
The R ′ / B ′ calculating unit 238 calculates R ′ / B ′ from the fluorescence light intensity data stored in the measurement data memory 237.
[0070]
The comparison unit 242 compares the reference value RE ′ stored in the storage unit 241 with R ′ / B ′ calculated by the R ′ / B ′ calculation unit 238.
[0071]
The comparison result is displayed on the monitor 180.
[0072]
Therefore, as described above, the fluorescence of the wavelength band of 480 nm ± 30 nm and the fluorescence of the wavelength band of 630 nm ± 30 nm are cut out from the fluorescence spectrum of the fluorescence guided by the quartz fiber, and R ′ / B ′ which is the ratio of the light intensity. Is calculated, compared with the reference value RE ′, and the comparison result is displayed, whereby information with improved reliability can be displayed.
[0073]
Further, in this apparatus, the distance between the measurement site and the tip of the quartz fiber 290 can be reduced, and sufficient light intensity can be obtained even when the detection bandwidth is 30 nm. Therefore, information with further improved reliability can be displayed by narrowing the cut-out wavelength band.
[0074]
In addition, by using a GaN-based semiconductor laser having a wavelength of 410 nm as the excitation light irradiation means, it is possible to reduce the size and cost of the apparatus without hindering the detection of light intensity.
[0075]
Further, in this apparatus, the comparison is made to display whether the ratio of the light intensity is larger or smaller than the reference value RE ′, but the light of the two wavelength bands detected without performing such a comparison. The ratio obtained by dividing the intensity can be displayed as it is, or each light intensity can be displayed by the additive color mixing method, and the ratio of the light intensity can be expressed as a change in the hue of the display screen.
[0076]
In addition, the monitors used in the devices according to the first and second embodiments have a monitor 170 for displaying normal image information and a monitor 180 for displaying comparison results, which are configured separately. Can also be used in combination. The display switching method at that time may be a method of automatically switching in time series, or a method in which the measurer arbitrarily switches using the switching means.
[0077]
Further, in each of the above embodiments, the ratio of the light intensity was obtained by cutting out the fluorescence in the wavelength band near 480 nm and the wavelength band near 630 nm, but the wavelength band near 700 nm was used instead of the fluorescence in the wavelength band near 630 nm. Alternatively, the fluorescence intensity may be cut out to obtain the ratio of the light intensity.
[0078]
Although the GaN-based semiconductor laser and the white light source are configured separately, a single light source can be used for both the excitation light and the white light source by using an appropriate optical transmission filter.
[0079]
Further, it goes without saying that it is possible to make changes within the basic configuration of the present invention, such as separating the excitation light guiding fiber and the fluorescence guiding fiber, or acquiring a normal image with an image fiber.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an endoscope apparatus as a first specific embodiment to which a fluorescent display device according to the present invention is applied.
FIG. 2 is a schematic configuration diagram of a mosaic filter used in the endoscope apparatus according to the first specific embodiment;
FIG. 3 is a schematic configuration diagram of an endoscope apparatus that is a second specific embodiment to which a fluorescent display device according to the present invention is applied;
FIG. 4 is a schematic configuration diagram of a switching filter used in the endoscope apparatus according to the second specific embodiment;
FIG. 5 is an explanatory diagram showing the intensity distribution of the fluorescence spectrum of fluorescence.
FIG. 6 is an explanatory diagram showing the intensity ratio distribution of the fluorescence spectrum of fluorescence.
[Explanation of symbols]
10,11 Measuring unit
20 Observation section
L1, L4 white light
L2, L5 excitation light
L3, L6 fluorescence
100,200 endoscope
101,201 Light guide
102,202 CCD cable
107,125,206 CCD image sensor
110,210 Lighting unit
111,211 White light source
114,214 GaN semiconductor laser
120 R / B calculation unit
121,231 Excitation light cut filter
123 Mosaic filter
124a, 124b Optical filter
127 Fluorescent image memory
128 R / B calculator
130,240 comparison unit
131,241 Memory unit
132,242 Comparison section
140,250 image processing unit
142,252 Normal image memory
143,253 Video signal generator
150,260 controller
170,180 monitor
220 Optical path separator
221 dichroic mirror
230 R '/ B' calculation unit
233 Switching filter
224a, 224b Optical filter
236 photodetector
237 Measurement data memory
238 R '/ B' calculator
290 quartz fiber

Claims (6)

Detects the light intensity in the wavelength band including all of the 480 nm ± 15 nm wavelength band and the light intensity in the predetermined wavelength band including 630 nm or 700 nm from the fluorescence emitted from the measurement part of the living body irradiated with the excitation light. And displaying information according to the ratio between the two. An excitation light irradiation means for irradiating the measurement part of the living body with the excitation light;
First fluorescence intensity detection means for detecting light intensity in a wavelength band including all of a wavelength band of 480 nm ± 15 nm from fluorescence emitted from the measurement unit by irradiation of the excitation light;
Second fluorescence intensity detection means for detecting light intensity in a predetermined wavelength band including 630 nm or 700 nm from fluorescence emitted from the measurement unit;
And a display means for displaying information according to a ratio between the light intensity detected by the first fluorescence intensity detection means and the light intensity detected by the second fluorescence intensity detection means. Fluorescent display device. A first wavelength selection unit that selects fluorescence in a wavelength band including all of a wavelength band of 480 nm ± 15 nm from fluorescence emitted from the measurement unit by irradiation of the excitation light; And a first light intensity detecting means for detecting the light intensity of the fluorescence selected by the first wavelength selecting means,
Second wavelength selection means for selecting fluorescence in a predetermined wavelength band including 630 nm or 700 nm from the fluorescence emitted from the measurement unit by the second fluorescence intensity detection means by irradiation of the excitation light; 3. The fluorescent display device according to claim 2, further comprising second light intensity detecting means for detecting the light intensity of the fluorescence selected by the wavelength selecting means.   The predetermined wavelength band selected by the first wavelength selection means is 480 nm ± 70 nm or less, and the predetermined wavelength band selected by the second wavelength selection means is 630 nm ± 70 nm or less or 700 nm ± 70 nm or less. The fluorescent display device according to claim 3.   The fluorescent display device according to claim 2, wherein a wavelength of the excitation light is 380 nm to 420 nm.   6. The fluorescent display device according to claim 2, wherein the excitation light irradiation means is a GaN semiconductor laser.

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