JP2016202411A - Fluorescent observation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide images with reduced positional deviation by improving the flame rate when observing fluorescent images of plural wavelengths in a visible light region and white light at the same time.SOLUTION: Provided is a fluorescent observation apparatus 1, comprising: a light source unit 3 which includes band light in respective wavelength regions for R, G, and B, and at least two band light beams of which emit illumination light having wavelength characteristics except some bands in the respective longer wavelength sides; a reflected-light imaging unit 55 for imaging reflected light of the band light from the light source unit 3 in a subject X; fluorescence imaging units 56, 58 for imaging two or more fluorescence beams in different bands generated by respective two or more band light beams; and an excitation light cutoff filter 57 arranged in front of the fluorescence imaging units 56, 58 and having the wavelength characteristics which cut off the band light but transmit two or more fluorescence beams having wavelengths in some bands. The fluorescence imaging units 56, 58 are capable of separately imaging the two or more fluorescence beams transmitted through the excitation light cutoff filter 57.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fluorescence observation apparatus.

  Conventionally, a fluorescence observation apparatus that realizes simultaneous observation of fluorescence of a plurality of wavelengths in white light and visible light regions is known (see, for example, Patent Document 1). In this fluorescence observation apparatus, white light and excitation light are sequentially irradiated onto a subject, and a white light image and a plurality of types of fluorescent images are acquired in order.

JP-A-7-155291

  However, in the fluorescence observation apparatus disclosed in Patent Document 1, the frame rate of each type of image is reduced according to the number of types of images to be acquired. Therefore, for example, when observing the inside of a living body while moving an endoscope, or observing an organ that moves greatly, the white light image acquired at a certain point in time and the white light image acquired next. In this case, the photographing range of the observation object is shifted due to the difference in photographing time. The white light image is mainly used for observing the form of the observation target, but there is a problem that it is difficult to observe the form of the observation target in detail with a white light image having a low frame rate.

  Furthermore, when the white light image and the fluorescent image are displayed on the monitor at the same time, the above-described shift in the photographing range of the observation target also occurs between the white light image and the fluorescent image. In particular, when observing a plurality of types of fluorescent images, there is a problem that the difference in shooting time between the white light image and each type of fluorescent image becomes larger and the shift of the shooting range becomes remarkable.

  The present invention has been made in view of the above-described circumstances, and provides an image in which misalignment is reduced by improving the frame rate when simultaneously observing a fluorescent image of a plurality of wavelengths in the visible light region simultaneously with white light. An object of the present invention is to provide a fluorescence observation apparatus capable of performing the above.

In order to achieve the above object, the present invention provides the following means.
One embodiment of the present invention includes band light in each wavelength region of R, G, and B, and at least two of the band lights emit illumination light having wavelength characteristics excluding a partial band on each long wavelength side. A light source unit, a reflected light image capturing unit that captures reflected light of the band light from the light source unit on a subject, and a fluorescence image capturing unit that captures two or more fluorescences in different bands generated by each of the two or more band light components; An excitation light cut filter that is disposed in front of the fluorescence imaging unit, blocks the band light, and has two or more wavelength characteristics that transmit the fluorescence having a wavelength in the partial band, and the fluorescence imaging unit Provides a fluorescence observation apparatus configured to be capable of imaging while distinguishing two or more of the fluorescence transmitted through the excitation light cut filter.

  According to this aspect, when R, G, and B band lights emitted from the light source unit are irradiated on the subject, the reflected light of the band light on the subject is captured by the reflected light imaging unit, and a reflected light image is acquired. The On the other hand, two or more fluorescences generated in a band deviated from these band lights by using two or more band lights as excitation light are transmitted through an excitation light cut filter provided in the front stage of the fluorescence imaging unit, and are transmitted from the light source unit. Light is blocked by the excitation light cut filter without entering the fluorescence imaging unit. Then, two or more bands of fluorescence that have passed through the excitation light cut filter are photographed while being distinguished by the fluorescence imaging unit, and fluorescence images of two or more wavelengths are acquired. As a result, since the reflected light can be continuously photographed, a reflected light image with a high frame rate can be provided. Furthermore, since two or more fluorescent images can be photographed simultaneously with the reflected light, it is possible to provide a fluorescent image in which the deviation of the photographing range from the reflected light image is reduced.

In the above aspect, the fluorescence imaging unit may include a variable spectroscopic element that switches a transmission band so as to selectively transmit two or more fluorescences in different bands.
In this way, two or more fluorescences are sequentially photographed by switching the transmission band of the variable spectral element. In this case as well, each fluorescent image is taken simultaneously with white light, so that two or more fluorescent lights can be observed simultaneously with white light.

Moreover, in the said aspect, the said fluorescence imaging part may consist of color image sensors.
By doing in this way, two or more bands of fluorescence transmitted through the excitation light cut filter are distinguished by the color filter of the color image sensor and photographed by separate pixels. Thereby, while continuously observing the reflected light image, a fluorescent image of two or more bands can be observed simultaneously with the reflected light image.

Moreover, in the said aspect, the said light source part may be provided with the white light source and the excitation filter which has the wavelength characteristic which permeate | transmits the said illumination light contained in the white light emitted from this white light source.
By doing so, it is possible to continuously observe the reflected light in the pseudo white light subject formed by mixing two or more band lights.

Moreover, in the said aspect, the display part and the display image control part which displays the reflected light image acquired by the said reflected light imaging part, and the two or more fluorescence images acquired by the said fluorescence imaging part on the said display part. The fluorescence imaging unit repeats the imaging of the two or more fluorescences and the acquisition of the two or more fluorescence images, with a period in which the two or more fluorescences are sequentially photographed one by one as a cycle. And the display unit may simultaneously display the two or more fluorescent images and the reflected light image captured at the same time or the closest time to any one of the two or more fluorescent images. .
In this way, when displaying a plurality of fluorescent images taken at different times together with the reflected light image, the fluorescent image and the reflected light image due to the difference between the fluorescent image, the reflected light image, and the shooting time. The influence of the deviation of the photographing range on the observation can be suppressed.

In the aspect described above, the display image control unit may cause the display unit to display the latest reflected light image and the two or more fluorescent images.
By doing in this way, the image displayed on a display part can be updated by the high frame rate same as the frame rate of a reflected light image and a fluorescence image, and the latest information of a to-be-photographed object can be provided to an observer.

Moreover, in the said aspect, the said reflected light imaging part may image | photograph reflected light only once in the approximate middle of 1 cycle in each cycle.
By doing so, the difference between the reflected light image and the photographing time of the plurality of fluorescent images photographed in the same cycle is made substantially equal, and the influence of the photographing range deviation between the plurality of fluorescent images and the reflected light image is affected. Can be suppressed.

Further, in the above aspect, the fluorescence imaging unit is capable of imaging while distinguishing the two or more fluorescences, and the light source unit simultaneously emits the band light during the imaging period by the reflected light imaging unit, Only one of the two or more band lights may be emitted during an imaging period using only the fluorescence imaging unit.
By doing so, it is possible to acquire an accurate fluorescence image that does not include crosstalk due to fluorescence of other colors in a period other than the imaging period of the reflected light.

Moreover, in the said aspect, the said light source part may increase the intensity | strength of the said band light during the imaging | photography period only by the said fluorescence imaging part compared with the imaging | photography period by the said reflected light imaging part.
By doing in this way, in a period other than the imaging period of the reflected light, higher intensity fluorescence can be generated and a brighter fluorescent image can be acquired.

  According to the present invention, when a fluorescent image having a plurality of wavelengths in the visible light region is observed at the same time as white light, it is possible to provide an image in which the frame rate is improved and the positional deviation is reduced.

1 is an overall configuration diagram of a fluorescence observation apparatus according to a first embodiment of the present invention. It is a figure which shows the wavelength characteristic example of the excitation filter with which the fluorescence observation apparatus of FIG. 1 is equipped, and an excitation light cut filter. It is a timing chart explaining operation | movement of the fluorescence observation apparatus of FIG. 6 is a timing chart showing a modification of the operation of the fluorescence observation apparatus in FIG. 1. 10 is a timing chart showing another modification of the operation of the fluorescence observation apparatus in FIG. 1. It is a figure which shows the other wavelength characteristic example of the excitation filter with which the fluorescence observation apparatus of FIG. 1 is provided, and an excitation light cut filter. It is a whole block diagram which shows the modification of the fluorescence observation apparatus of FIG. It is a timing chart explaining the operation of FIG. It is a timing chart explaining operation | movement of the fluorescence observation apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the wavelength characteristic example of the modification of the excitation filter with which the fluorescence observation apparatus of FIG. 9 is equipped, and an excitation light cut filter. It is a timing chart explaining the modification of operation | movement of the fluorescence observation apparatus of FIG. 10 is a timing chart for explaining another modified example of the operation of the fluorescence observation apparatus in FIG. 9. 10 is a timing chart for explaining another modified example of the operation of the fluorescence observation apparatus in FIG. 9. 10 is a timing chart for explaining another modified example of the operation of the fluorescence observation apparatus in FIG. 9. 10 is a timing chart for explaining another modified example of the operation of the fluorescence observation apparatus in FIG. 9. 10 is a timing chart for explaining another modified example of the operation of the fluorescence observation apparatus in FIG. 9. It is a whole block diagram of the fluorescence observation apparatus which concerns on the 3rd Embodiment of this invention. It is a timing chart explaining operation | movement of the fluorescence observation apparatus of FIG.

(First embodiment)
A fluorescence observation apparatus 1 according to a first embodiment of the present invention will be described below with reference to FIGS.
A fluorescence observation apparatus 1 according to this embodiment is a fluorescence endoscope apparatus, and as illustrated in FIG. 1, an elongated insertion part 2 to be inserted into a body, a light source unit (light source part) 3, and the light source An illumination unit 4 that irradiates the illumination light from the unit 3 toward the living tissue (subject) X from the distal end 2a of the insertion portion 2 and the vicinity of the distal end 2a of the insertion portion 2, and acquires an image signal of the biological tissue X An imaging unit 5, an imaging condition setting unit 7 for setting imaging conditions, a light source unit 3 and an imaging unit 5 according to the set imaging conditions, a processor 6 that generates an image, and a processor 6 that generates the image signal And a monitor 8 for displaying the obtained images P and Q.

  The light source unit 3 includes a white light source 31 that generates white light and an excitation filter (triple band pass) that transmits one band light in each of the R, G, and B wavelength regions from the white light emitted from the white light source 31. Filter) 32, and a coupling lens 33 for condensing the three band lights transmitted through the excitation filter 32. Since the three band lights transmitted through the excitation filter 32 have R, G, and B bands, the light collected by the coupling lens 33 constitutes pseudo white light. On the other hand, the three band lights that have passed through the excitation filter 32 act as excitation light that excites fluorescent substances present in the living tissue X, respectively. The fluorescence generated in the living tissue X by being excited by each band light has a wavelength (wavelength in a notch band described later) different from that of the band light.

  The illumination unit 4 includes a light guide fiber 41 disposed in the insertion portion 2 and an illumination optical system 42 provided at the distal end 2a of the insertion portion 2. The light guide fiber 41 guides the light collected by the coupling lens 33 from its proximal end to its distal end. The illumination optical system 42 emits pseudo white light emitted from the distal end of the light guide fiber 41 to the living tissue X facing the distal end 2 a of the insertion portion 2.

  The imaging unit 5 includes an objective lens 51 that collects light from the living tissue X, a beam splitter 52 that divides the light collected by the objective lens 51 into two, and the light that is divided by the beam splitter 52. Two condensing lenses 53 and 54 that illuminate, and a first image sensor (reflected light imaging unit) 55 and a second image sensor (fluorescence imaging unit) that shoot the light collected by the condensing lenses 53 and 54, respectively. ) 56, an excitation light cut filter 57 that is disposed between the beam splitter 52 and the second image sensor 56 and selectively transmits only fluorescence, and selectively transmits fluorescence having different wavelengths by switching the transmission band. A variable spectroscopic element (fluorescence imaging unit) 58 for transmission is provided.

  FIG. 2 shows transmittance characteristics (wavelength characteristics) of the excitation filter 32 and the excitation light cut filter 57. The excitation filter 32 transmits light of three bands with a wavelength interval, and the excitation light cut filter 57 blocks light having a wavelength that passes through the excitation filter 32 and transmits light having a wavelength that does not pass through the excitation filter 32. It is supposed to let you.

  Specifically, the excitation filter 32 includes R (about 600 nm to about 700 nm), G (about 500 nm to about 600 nm), and B (about 400 nm to about 500 nm) in the visible light range (wavelength of about 400 nm to about 700 nm). Each wavelength region has a transmission band for transmitting light (see the solid line in FIG. 2). The excitation filter 32 emits light at three locations on the long wavelength side between the B transmission band and the G transmission band, between the G transmission band and the R transmission band, and the R transmission band. It has a notch band to cut off. The three notch bands respectively correspond to the wavelengths of fluorescence excited by the three band lights transmitted through the R, G, and B transmission bands. The excitation light cut filter 57 has a transmission band (see a chain line in FIG. 2) that transmits fluorescence in a wavelength region that overlaps with the notch band.

The beam splitter 52 divides the light collected by the objective lens 51 into two, reflects one toward the first image sensor 55 and transmits the other toward the second image sensor 56. ing.
The first image sensor 55 is, for example, a color CCD or a color CMOS, and color-reflects the reflected light from the living tissue X reflected by the beam splitter 52 to generate a reflected light image signal.
The second imaging element 56 is, for example, a high-sensitivity monochrome CCD, and captures fluorescence emitted from the living tissue X and transmitted through the excitation light cut filter 57 and the variable spectral element 58 to generate a fluorescence image signal. It has become.

  The imaging condition setting unit 7 is an apparatus for inputting an imaging condition of reflected light by the first imaging element 55 and an imaging condition of fluorescence by the second imaging element 56 using an input unit (not shown). The imaging conditions are, for example, exposure time, gain, fluorescence wavelength, and the like. The imaging conditions set by the imaging condition setting unit 7 are transmitted to the control signal generation unit 63 of the processor 6.

  The processor 6 includes a reflected light image generation unit 61 that generates a reflected light image P from the reflected light image signal acquired by the first image sensor 55, and a fluorescent image from the fluorescent image signal acquired by the second image sensor 56. A fluorescence image generation unit 62 that generates Q, a control signal generation unit 63, and a display image control unit 64 are provided. The control signal generation unit 63 controls the white light source 31, the imaging elements 55 and 56, and the variable spectral element 58 according to the set imaging conditions. The display image control unit 64 outputs the reflected light image P generated by the reflected light image generating unit 61 and the fluorescent image Q generated by the fluorescent image generating unit 62 to the monitor 8 for display at a predetermined frame rate.

  Hereinafter, when the imaging conditions are set in the imaging condition setting unit 7 so that the first imaging element 55 and the second imaging element 56 are set to the same frame rate and three colors of fluorescence are captured. Will be described. In this case, as shown in FIG. 3, the control signal generation unit 63 causes the second image sensor 56 to perform one-color fluorescence exposure as well as one exposure by the first image sensor 55. Further, the control signal control unit 63 repeats sequentially performing the three-color fluorescence exposure by the second image sensor 56 together with the three exposures by the first image sensor 55.

  More specifically, as shown in FIG. 3, when the observation is started, the control signal generator 63 continuously turns on the white light source 31 to continuously generate white light, and the first signal is generated. Shooting of reflected light (white exposure) by the image sensor 55 is performed in each frame, and the variable spectral element 58 is controlled, and the wavelength band of the transmitted fluorescence is excited by three band lights of R, G, and B. Are sequentially switched to the wavelength bands of the fluorescence (hereinafter referred to as R fluorescence, G fluorescence, and B fluorescence).

  The “display image” stage of the timing chart of FIG. 3 shows a combination of the reflected light image P and the fluorescence image Q displayed on the monitor 8 in each frame. For example, when reflected light and R fluorescence are photographed in “white exposure (first time)” and “R fluorescence exposure (first time)” of the first frame, respectively, “white exposure (first time)” and “R fluorescence exposure”. The “reflected light image (first time)” and “R fluorescence image (first time)” acquired by “(first time)” are displayed on the monitor 8 in the next frame.

The operation of the fluorescence observation apparatus 1 according to this embodiment configured as described above will be described below.
When the observer sets the imaging conditions via the imaging condition setting unit 7, the control signal generation unit 63 turns on the white light source 31 and controls the imaging elements 55 and 56 and the variable spectral element 58.

  When the white light source 31 is turned on, white light emitted from the white light source 31 is allowed to pass through the excitation filter 32, whereby a part of the wavelength band is cut out and R, G, and B having a wavelength interval are separated. Illumination light including light in a partial band of each wavelength region is incident on the light guide fiber 41 by the coupling lens 33. The excitation filter 32 partially cuts out a part of the white light band. However, since the light transmitted through the excitation filter 32 includes all the light in the R, G, and B bands, After being guided as light to the distal end 2a of the insertion portion 2 by the light guide fiber 41, the illumination optical system 42 irradiates the living tissue X.

  When the pseudo white light is irradiated onto the living tissue X, the reflected light reflected on the surface of the living tissue X and the fluorescence caused by the excitation of the fluorescent substance existing in the living tissue X return light. Is collected by the objective lens 51 of the imaging unit 5. The light condensed by the objective lens 51 is branched into two by the beam splitter 52, one light is incident on the first image sensor 55 via the condensing lens 53, and the other light is the excitation light cut filter. Light having a wavelength that has passed through 57 is collected by the condenser lens 54, and light having a wavelength that has passed through the variable spectroscopic element 58 is incident on the second image sensor 56.

  The light incident on the first image sensor 55 includes fluorescence in addition to the reflected light of the illumination light, but the fluorescence in the reflected light image signal is negligible due to the difference in intensity between the reflected light and the fluorescence. is there. Then, the reflected light image signal generated by the first image sensor 55 is input to the reflected light image generation unit 61, whereby the reflected light image P is generated. The generated reflected light image P is sent to the display image control unit 64 and displayed on the monitor 8.

Further, the other light branched by the beam splitter 52 is allowed to pass through the excitation light cut filter 57, whereby all the light from the light source unit 3 is removed, and only the fluorescence generated in the living tissue X is changed to the variable spectroscopic element. 58 is incident. The control signal generation unit 63 controls the variable spectroscopic element 58 to switch the fluorescence wavelength to be transmitted for each frame, thereby sequentially transmitting the R fluorescence, the G fluorescence, and the B fluorescence. Thereby, R fluorescence, G fluorescence, and B fluorescence are separately photographed for each frame, and a fluorescence image signal is generated. The fluorescence image signal is sequentially sent to the fluorescence image generation unit 62, whereby fluorescence images (R fluorescence image, G fluorescence image, and B fluorescence image) Q corresponding to R, G, and B are acquired.
Then, the generated fluorescence image Q is sequentially displayed on the monitor 8 by being sent to the display image control unit 64.

  As described above, according to the fluorescence observation apparatus 1 according to the present embodiment, the reflected light of the pseudo white light in the living tissue X is continuously photographed by the first imaging element 55, and thus the reflection of the living tissue X is reflected. The light image P can be continuously displayed on the monitor 8 at a high frame rate. On the other hand, the fluorescence image Q based on the band light of any of R, G, and B is acquired simultaneously with the white light in any frame. Therefore, there is an advantage that simultaneous observation of fluorescent images of a plurality of wavelengths can be performed while continuously performing observation with white light. In addition, since the difference in shooting time between the reflected light image P and each fluorescent image Q is zero or reduced, the fluorescent image Q having the same shooting range with respect to the reflected light image P or having a small shift in the shooting range. There is an advantage that it can be provided.

  In the present embodiment, the fluorescence images Q in the three bands are sequentially acquired, but instead of this, one of the fluorescence images Q in the three bands may be continuously acquired. For example, the imaging condition setting unit 7 is configured so that the observer can select and set one of the fluorescent images Q in three bands, and the control signal unit 63 is set to the fluorescent image Q set in the imaging condition setting unit 7. The variable spectroscopic element 58 is controlled so that is continuously acquired. The observer can switch from the currently acquired fluorescent image Q to the fluorescent image Q in another band by changing the setting of the imaging condition setting unit 7.

  Further, in the present embodiment, the exposure time of the reflected light image P and the exposure time of the fluorescent image Q are made equal to the time required for one frame, but instead, as shown in FIG. The exposure time of the reflected light image P and the exposure time of the fluorescent image Q may be different. In the example shown in FIG. 4, the exposure time of the fluorescent image Q is set to twice the exposure time of the reflected light image P, and a brighter fluorescent image Q can be acquired. The exposure time of the reflected light image P and the exposure time of the fluorescent image Q are set, for example, when the observer inputs a desired exposure time to the imaging condition setting unit 7 using an input unit before observation. The exposure time of the fluorescent image Q and the reflected light image P may be set at an arbitrary ratio.

  In the present embodiment, the fluorescence of the three bands is photographed using the excitation filter 32 formed of a triple band pass filter and the excitation light cut filter 57 that blocks the three bands. Then, as shown in FIG. 5, fluorescence of two bands may be photographed with the same configuration. In this case, it is only necessary to pass only two bands of fluorescence to the second image sensor 56 by the variable spectroscopic element 58. By reducing the number of fluorescent images captured by the second image sensor 56, the frame rate of the fluorescent image Q in each band can be improved.

  When only two bands of fluorescence are imaged, an excitation filter 32 that cuts off the two bands of white light and an excitation light cut filter that passes the bands of fluorescence and cuts off the other bands of white light. 57 may be used. For example, in order to photograph two fluorescences excited by light in the R and B wavelength bands, the excitation filter 32 and the excitation light cut filter 57 having the wavelength characteristics shown in FIG. 6 may be used.

  In the fluorescence observation apparatus 1 according to the present embodiment, the fluorescence transmitted through the excitation light cut filter 57 is selectively transmitted by the variable spectroscopic element 58. Instead, the variable spectroscopic element 58 and the excitation are used instead. The order of the light cut filter 57 may be changed.

Further, in the fluorescence imaging unit of the present embodiment, the variable spectroscopic element 58 selectively transmits fluorescence of two or more bands in order and separately photographs simultaneously with white light. As shown in FIG. 7, the variable spectral element 58 may be eliminated and a color CCD (hereinafter also referred to as a color CCD 56) may be employed as the second imaging element 56.
In this way, two or more bands of fluorescence from which reflected light has been removed by the excitation light cut filter 57 are selected by the color filters provided in each pixel of the color CCD 56 and photographed by different pixels. Thereby, it is possible to distinguish and photograph two or more bands of fluorescence.

In this case, as shown in FIG. 8, there is an advantage that all fluorescence in two or more bands can be photographed simultaneously.
Further, instead of the color CCD 56 in this case, three CCDs (such as a three-plate CCD) that diverge and photograph each band may be employed.
Further, the time of one frame of the reflected light image P and the fluorescent image Q may be the same or different.

(Second Embodiment)
Next, a fluorescence observation apparatus according to the second embodiment of the present invention will be described below with reference to FIGS.
In the description of the present embodiment, portions having the same configuration as those of the fluorescence observation apparatus 1 according to the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 9, the fluorescence observation apparatus according to the present embodiment is the first implementation in that the display image control unit 64 displays the fluorescence images of two or more bands on the monitor 8 simultaneously instead of alternately. This is different from the fluorescence observation apparatus 1 according to the embodiment.

  Similarly to the fluorescence observation apparatus 1 in FIG. 5, the fluorescence observation apparatus alternately captures two colors of fluorescence excited by band light of two colors (R and B in the illustrated example) to obtain an R fluorescence image Q and B fluorescence images Q are acquired alternately.

  That is, the excitation filter 32 and the excitation light cut filter 57 having the wavelength characteristics shown in FIG. 6 are used. The excitation filter 32 has notch bands at two locations between the B transmission band and the G transmission band and on the long wavelength side of the R transmission band, and the excitation light cut filter 57 corresponds to the notch band. B fluorescence and R fluorescence are transmitted.

  As shown in FIG. 9, the control signal generation unit 63 performs one-color fluorescence exposure using the second image sensor 55 for each exposure performed by the first image sensor 55, and the second image sensor 56, the reflective light source 31, the first image sensor 55, the second image sensor 56, and the variable light source 31, the second image sensor 56, and the variable light source 31, the second image sensor 56, and the variable light source 31. The spectroscopic element 58 is controlled. As a result, two frames of the reflected light image P are acquired and one frame of the R fluorescent image Q and one of the B fluorescent image Q are acquired during one cycle, which is the minimum repeating unit for repeated shooting.

The display image control unit 64 generates a superimposed image by superimposing the reflected light image P, the R fluorescent image Q, and the B fluorescent image Q acquired during the same cycle, and outputs the generated superimposed image to the monitor 8. Display.
At this time, two frames of the reflected light image P are acquired during the same cycle. Hereinafter, the first reflected light image acquired at the same time as the R fluorescent image Q is referred to as a first reflected light image P, and the second reflected light image acquired at the same time as the B fluorescent image Q is referred to as a second. The reflected light image P.

  In the present embodiment, the imaging condition setting unit 7 is configured so that the observer can select and set which of the first reflected light image P and the second reflected light image P is used to generate the superimposed image. ing. The display image control unit 64 uses one reflected light image P set by the observer via the imaging condition setting unit 7 to generate a superimposed image. In the example shown in FIG. 9, the second reflected light image P is used as the superimposed image.

As a reference for selecting the reflected light image P, the intensity of fluorescence and the width of the distribution range can be cited.
When a plurality of fluorescent images Q having different photographing times are superimposed on the reflected light image P, the photographing time of at least one fluorescent image Q is different from the photographing time of the reflected light image P. Therefore, when the relative position between the distal end 2a of the insertion portion 2 and the living tissue X changes with time due to the movement of the insertion portion 2 or the movement of the organ, a plurality of fluorescent images Q acquired during the same cycle. At least one of them has a photographing range shift with respect to the reflected light image P.

At this time, when the fluorescence image Q is obtained by photographing fluorescence that is distributed over a wide range, such as autofluorescence, even if the photographing range of the fluorescent image Q is deviated from the photographing range of the reflected light image P, this photographing is performed. The range shift is not conspicuous in the superimposed image, and the influence on the observation by the observer is small. On the other hand, when the fluorescence image Q is a photograph of localized fluorescence such as drug fluorescence, a shift between the imaging range of the fluorescence image Q and the imaging range of the reflected light image P appears remarkably in the superimposed image. The effect on observation by a person is great. Therefore, the observer selects, for example, the reflected light image P acquired at the same time as the fluorescence image Q obtained by photographing the localized fluorescence.
Alternatively, the observer may actually observe both the superimposed image using the first reflected light image P1 and the superimposed image using the second reflected light image P2, and select a suitable one for observation. .

  As described above, according to the fluorescence observation apparatus according to the present embodiment, one of the two frames of the reflected light image P acquired during the same cycle has a larger influence on the observation due to the deviation of the photographing range from the fluorescence image Q. The reflected light image P is selected and a superimposed image is generated. Thereby, there exists an advantage that the superimposed image which consists of a combination of the some fluorescence image Q and reflected light image P suitable for observation can be provided to an observer.

  In the present embodiment, the R filter and the B fluorescence are photographed using the excitation filter 32 and the excitation light cut filter 57 having the wavelength characteristics shown in FIG. The wavelength characteristics of the cut filter 57 can be changed as appropriate. For example, B fluorescence and G fluorescence may be imaged using the excitation filter 32 and the excitation light cut filter 57 having the wavelength characteristics shown in FIG.

  In this embodiment, the observer selects the reflected light image P to be used for the superimposed image. Instead, the display image control unit 64 changes the intensity of the fluorescence image Q and the distribution range of the fluorescence. You may select based on an area. For example, the display image control unit 64 selects a pixel having a gradation value equal to or higher than a predetermined threshold from each of the R fluorescent image Q and the B fluorescent image Q, and the number of selected pixels (that is, the fluorescent distribution range). The reflected light image acquired at the same time as the smaller fluorescent image may be selected.

In the present embodiment, the superimposed image is generated from the reflected light image P, the R fluorescent image Q, and the B fluorescent image Q acquired during the same cycle. Instead, the superimposed image is shown in FIG. As described above, a superimposed image may be generated from the latest reflected light image P, R fluorescence image Q, and B fluorescence image Q.
In the case of the method of FIG. 9, the same superimposed image continues to be displayed during the same cycle. On the other hand, in the case of the method shown in FIG. 11, since the image constituting the superimposed image is updated during the same cycle, the frame rate becomes twice that in the method shown in FIG. Can be displayed.

Further, in the present embodiment, FIGS. 12 to 16 show a case where a superimposed image is generated by superimposing a reflected light image P of one frame and a fluorescent image Q of a plurality of frames acquired during the same cycle. As described above, the reflected light that does not contribute to the generation of the superimposed image may be omitted, and the reflected light may be captured only once during one cycle.
By doing so, it is possible to obtain an accurate fluorescent image Q that does not include crosstalk of fluorescence of other colors in a period other than the imaging period of the reflected light.

  Further, in the period when the reflected light is not photographed by the first image sensor 55, as shown in FIG. 13, the output intensity of the light source 31 is increased so that a brighter fluorescent image Q is acquired. Also good.

Further, when the reflected light is photographed only once in one cycle, the reflected light photographing timing can be set to approximately the center in one cycle as shown in FIGS. preferable.
By doing in this way, the imaging range of one fluorescence image Q does not largely deviate from the imaging range of the reflected light image P, and a superimposed image that suppresses the influence on observation can be generated.

In the present embodiment, as shown in FIG. 15, when the exposure time of reflected light by the first image sensor 55 is shorter than the exposure time of fluorescence by the second image sensor 56, the first It is preferable to match the timing of the middle of the exposure time of the imaging element 55 with the middle of one cycle. Here, not the middle of the frame of the first image sensor 55 but the middle timing of the exposure time is made to coincide with the middle of one cycle, so that the deviation of the photographing range is reduced.
In the present embodiment, as shown in FIG. 16, similarly to the first embodiment, R fluorescence, G fluorescence, and B fluorescence may be captured in order during one cycle.
In this embodiment, the reflected light image P of one frame and the fluorescent image Q of a plurality of frames are superimposed on each other and displayed on the monitor 8. Instead, they are displayed on the monitor 8 in parallel. May be.

(Third embodiment)
Next, a fluorescence observation apparatus 10 according to a third embodiment of the present invention will be described below with reference to FIGS. 17 and 18.
In the description of the present embodiment, portions having the same configuration as those of the fluorescence observation apparatuses 1 and 10 according to the first and second embodiments described above are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 17, the fluorescence observation apparatus 10 according to the present embodiment employs LEDs 34, 35, and 36 that emit R, G, and B band lights as light sources, and the second imaging element 56. As a difference from the fluorescence observation apparatus 1 according to the first and second embodiments, a color CCD that can shoot by distinguishing three colors of fluorescence is employed and R fluorescence, G fluorescence, and B fluorescence are observed. Yes.
In place of the color CCD, three CCDs that perform spectral imaging for each band may be employed.

  As shown in FIG. 18, the control signal generator 63 controls the first image sensor 55 to perform exposure only once in one cycle, and performs exposure three times in one cycle. Thus, the second image sensor 56 is controlled. Further, the control signal generation unit 63 includes only the B-LED 36 during the first exposure period and the LEDs 34 of all three colors during the second exposure period among the three exposures by the second image sensor 56. , 35, and 36 control the three LEDs 34, 35, and 36 so that only the R-LED 34 is turned on during the third exposure period. Thereby, in one cycle, the R fluorescence image Q, the G fluorescence image Q, and the B fluorescence image Q are acquired in order, and the reflected light image P is acquired simultaneously with the G fluorescence image Q.

  The display image control unit 64 generates a superimposed image by superimposing the reflected light image P, the B fluorescent image Q, the G fluorescent image Q, and the R fluorescent image Q acquired during the same cycle, and monitors the generated superimposed image. Output to 8 and display.

  As described above, according to the fluorescence observation apparatus 10 according to the present embodiment, the exposure time of the reflected light image P is approximately halfway within one cycle, whereby the photographing time of the B fluorescence image Q and the reflected light image P is set. The difference and the difference in photographing time between the R fluorescent image Q and the reflected light image P are substantially equal. Accordingly, there is an advantage that a deviation between the imaging range of the B fluorescent image and the R fluorescent image and the imaging range of the reflected light image in the superimposed image is suppressed, and a superimposed image suitable for observation can be provided to the observer. In addition, since only one color LED 36 or 34 is lit during the exposure period of B fluorescence and R fluorescence, accurate B fluorescence image Q and R fluorescence image Q that do not include crosstalk of fluorescence of other colors are acquired. There is an advantage that you can.

Also in this embodiment, the output intensity of the LEDs 34, 35, 36 may be increased during a period other than the exposure period of the reflected light so that a brighter fluorescent image Q is acquired.
In the present embodiment, band light is emitted in the order of B, G, and R in one cycle, but the order of the three color band lights can be changed as appropriate. For example, in order to further prevent crosstalk, it is preferable to set the order of the band light so that the B fluorescence is exposed simultaneously with the reflected light. The fluorescence spectrum has a characteristic of spreading to the longer wavelength side. Therefore, when photographing reflected light in which all of R fluorescence, G fluorescence and B fluorescence are generated, it is difficult to photograph G fluorescence and R fluorescence without including crosstalk of fluorescence of other colors, but it has the shortest wavelength. B fluorescence can be photographed without including crosstalk between G fluorescence and R fluorescence.

1,10 Fluorescence observation equipment 3 Light source unit (light source part)
31 White light source
32 Excitation filter 34, 35, 36 LED (light source)
55 1st imaging device (reflected light imaging part)
56 Second imaging device (fluorescence imaging unit)
57 Excitation light cut filter 58 Variable spectral element (fluorescence imaging unit)
61 Reflected light image generation unit X biological tissue (subject)
P Reflected light image

Claims (9)

A light source unit that includes band light in each wavelength region of R, G, and B, and at least two of the band lights emit illumination light having a wavelength characteristic excluding a partial band on each long wavelength side;
A reflected light imaging unit that captures reflected light in the subject of the band light from the light source unit;
A fluorescence imaging unit that captures two or more fluorescences in different bands generated by each of the two or more band lights;
An excitation light cut filter having a wavelength characteristic that is disposed in front of the fluorescence imaging unit, blocks the band light, and transmits two or more fluorescent lights having wavelengths in the partial band;
The fluorescence observation apparatus in which the fluorescence imaging unit is configured to be able to photograph by distinguishing two or more fluorescences transmitted through the excitation light cut filter.   The fluorescence observation apparatus according to claim 1, wherein the fluorescence imaging unit includes a variable spectroscopic element that switches a transmission band so as to selectively transmit two or more of the fluorescences in different bands.   The fluorescence observation apparatus according to claim 1, wherein the fluorescence imaging unit includes a color imaging element.   The fluorescence according to any one of claims 1 to 3, wherein the light source unit includes a white light source and an excitation filter having a wavelength characteristic that transmits the illumination light included in the white light emitted from the white light source. Observation device. A display unit;
A display image control unit that causes the display unit to display a reflected light image acquired by the reflected light imaging unit and two or more fluorescent images acquired by the fluorescent imaging unit;
The fluorescence imaging unit repeats the imaging of the two or more fluorescences and the acquisition of the two or more fluorescence images, with a period in which the two or more fluorescences are sequentially photographed one by one as a cycle.
The display image control unit causes the display unit to simultaneously display the two or more fluorescent images and the reflected light image photographed at the same time or the closest time to any one of the two or more fluorescent images. Item 5. The fluorescence observation apparatus according to any one of Items 1 to 4.   The fluorescence observation apparatus according to claim 5, wherein the display image control unit displays the latest reflected light image and the two or more fluorescence images on the display unit.   The fluorescence observation apparatus according to claim 5 or 6, wherein the reflected light imaging unit captures the reflected light only once in approximately the middle of one cycle in each cycle. The fluorescence imaging unit is capable of distinguishing and photographing the two or more fluorescences;
The light source unit simultaneously emits the band light during a photographing period by the reflected light imaging unit, and emits only one of the two or more band lights during a photographing period by only the fluorescent imaging unit. The fluorescence observation apparatus according to claim 7.   The fluorescence observation apparatus according to claim 7 or 8, wherein the light source unit increases the intensity of the band light during an imaging period using only the fluorescent imaging unit as compared with an imaging period using the reflected light imaging unit. .

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