JP2011177436A - Fluorescent endoscope system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent endoscope system in which light source can be downsized, and form information of an observation object obtained by a reflected image and position information of a lesion obtained by a fluorescent image can be detected with a high degree of accuracy in one observation mode. <P>SOLUTION: The fluorescent endoscope system which emits an excitation light and a reflected image-acquiring light to a living tissue 5 has: an illuminator 12, 23, 21 which simultaneously emits the excitation light and the reflected image-acquiring light to the living tissue by using one light source 11; a light intensity-adjuster 12 which adjusts an intensity of the reflected image-acquiring light so that the intensity of the reflected image-acquiring light reflected from the living tissue is nearly equal to an intensity of a fluorescence emitted form the living tissue; a filter 22c which cuts the excitation light reflected from the living tissue; a wavelength-separator which separates a wavelength of the reflected image-acquiring light reflected from the living tissue from a wavelength of the fluorescence emitted form the living tissue; and an imager 22d which individually takes the reflected image and the fluorescent image which are separated through the wavelength-separator. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fluorescence endoscope apparatus that acquires position information of a lesion in a biological tissue based on a fluorescence image and morphological information of the biological tissue based on a reflection image.

  In fluorescence observation using an endoscope, the distribution of a fluorescent dye with respect to a living tissue based on a fluorescence image is acquired as position information of a lesioned part. At that time, it is essential to grasp morphological information of an observation target.

  By the way, the morphological information can be acquired from a reflection image when the observation target is irradiated with visible light. Therefore, for a living body to be observed, if two observation modes of fluorescence image observation using excitation light and reflection image observation using visible light such as white light are used, a lesioned part in the living tissue is used. Position information and morphological information of the living tissue can be acquired.

However, in observation using an endoscope, an observer inserts an insertion portion into a living body and observes an observation target portion of the living tissue while moving the distal end of the insertion portion. For this reason, if the fluorescence image observation and the reflection image observation are performed by the switching operation of the observation mode, the switching operation becomes complicated and the burden on the observer increases, and the time required for the switching operation of the observation mode is increased. With the progress, it becomes easy to cause a shift of the observation target part between the observation target when the morphological information is acquired and the position information of the lesioned part.
For this reason, in fluorescence observation using an endoscope, acquisition of morphological information of an observation target using a reflection image and acquisition of position information of a lesion site using a fluorescence image can be performed in one observation mode. It is desirable.

  Conventionally, as a fluorescence endoscope apparatus that acquires a reflection image and a fluorescence image in one observation mode, for example, there is a fluorescence endoscope apparatus described in Patent Document 1 below.

JP 2005-329115 A

  In the fluorescence endoscope apparatus described in Patent Document 1, each filter is provided by rotating a filter turret including a filter that transmits reflected image acquisition light and a filter that transmits excitation light in the circumferential direction in the light source unit. Are sequentially inserted into the optical path from the light source, and the reflected image reflected from the observation object and the fluorescence image emitted from the observation object are sequentially acquired via the CCD.

  However, as in the fluorescence endoscope apparatus described in Patent Document 1, by rotating the filter turret to obtain the reflection image and the fluorescence image repeatedly in a frame sequential manner, a rotation space for the filter turret is required. As a result, the light source section becomes large.

  In order to obtain a good image, it is necessary to adjust the rotation speed of the filter turret according to the condition of the observation target and change the exposure time. However, the filter turret has a structure in which the rotation shaft is rotated through mechanical drive means such as a motor, and it is difficult to adjust the rotation speed with high accuracy.

  Moreover, the fluorescence emitted from the observation object has an extremely weak light intensity compared to the reflected light reflected from the observation object. For this reason, it is necessary to greatly vary the irradiation time of the excitation light for obtaining the fluorescence image and the irradiation time of the light for obtaining the reflection image for obtaining the reflection image. However, a filter that transmits reflected image acquisition light and a filter that transmits excitation light, which are used in the fluorescence endoscope apparatus described in Patent Document 1, are provided in the circumferential direction. In the filter turret that switches to, the irradiation time is adjusted to a different rotational speed when a filter that transmits reflected image acquisition light is inserted in the optical path and when a filter that transmits excitation light is inserted in the optical path. Is very difficult to adjust with high precision.

  The present invention has been made in view of the above-described conventional problems, and can reduce the size of the light source unit. In one observation mode, the morphological information of the observation target by the reflection image and the lesion part by the fluorescence image can be obtained. An object of the present invention is to provide a fluorescence endoscope apparatus capable of detecting position information with high accuracy.

  In order to achieve the above object, a fluorescence endoscope apparatus according to the present invention irradiates a living tissue with excitation light and light for obtaining a reflected image, and reflects the fluorescence generated from the living tissue and the reflected image reflected by the living tissue. A fluorescence endoscope apparatus for observing the position of a lesioned part in the living tissue and the form of the living tissue using light for acquisition, and using the single light source, the excitation light, the excitation light, and Illumination means configured to simultaneously irradiate the biological tissue with the reflected image acquisition light having a wavelength different from that of the fluorescence, and the intensity of the reflected image acquisition light reflected by the biological tissue includes: Light for adjusting the intensity of the reflected image acquisition light emitted from the light source or the intensity of the reflected image acquisition light reflected by the biological tissue so as to be approximately the same as the intensity of the fluorescence generated from the biological tissue. Intensity adjusting means and reflected by the living tissue An excitation cut filter for cutting the excitation light; wavelength separation means for separating a wavelength of the reflected image acquisition light reflected by the biological tissue and a wavelength of the fluorescence generated from the biological tissue; and the wavelength separation means It has the imaging means which acquires separately the reflected image and fluorescence image which were separated via the.

  In the fluorescence endoscope apparatus of the present invention, the reflected image acquisition wavelength transmission region that transmits the wavelength of the reflected image acquisition light reflected by the biological tissue and the wavelength of the fluorescence generated from the biological tissue are transmitted. A color CCD comprising a mosaic filter having a fluorescence wavelength transmission region to be mosaiced and a single plate image sensor, the wavelength separation means comprising the mosaic filter, and the imaging means being in the single plate image sensor It is preferable that the pixel comprises pixels corresponding to each mosaic area provided in the mosaic filter.

  In the fluorescence endoscope apparatus of the present invention, a monochromatic CCD composed of a single-plate image sensor is provided, and the wavelength separation unit is configured to detect the wavelength of the reflected image acquisition light reflected by the biological tissue and the biological tissue. It is preferable that the wavelength of the generated fluorescence is composed of a spectroscopic optical element that is switched in a time division manner and transmitted, and the imaging means is composed of all pixels in the single-plate image sensor.

  In the fluorescence endoscope apparatus of the present invention, the irradiating means simultaneously extracts the excitation light and the reflected image acquisition light having different wavelengths from the excitation light and the fluorescence from the light emitted from the light source. It is preferable that the light intensity adjusting means includes the multiple wavelength extraction filter.

  In the fluorescence endoscope apparatus according to the present invention, the spectroscopic optical element has a wavelength of maximum transmittance that is transmitted as the reflected image acquisition light reflected by the biological tissue, and the reflected image emitted by the light source. Preferably, the light intensity adjusting unit is configured to deviate from the wavelength of the maximum intensity in the light for acquisition, and the light intensity adjusting unit includes the spectroscopic optical element.

  According to the present invention, a fluorescent endoscope capable of reducing the size of a light source unit and accurately detecting the shape information of an observation target by a reflected image and the position information of a lesioned part by a fluorescent image in one observation mode. A device is obtained.

1 is a block diagram schematically showing an overall configuration of a fluorescence endoscope apparatus according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram showing optical characteristics of a filter or the like used in the fluorescence endoscope apparatus of FIG. 1, (a) is a transmittance of a fluorescence observation illumination filter, (b) is a transmittance of an excitation light cut filter, ( c) shows the transmittance of each filter provided in the mosaic CCD, and (d) shows the wavelength range and intensity of the detected fluorescence and reflected light. In the fluorescence endoscope apparatus shown in FIG. 1, a filter switching member used in a case where the observation with normal white light can be switched in addition to the observation with fluorescence and reflected light, and the fluorescence endoscope apparatus described in Patent Document 1 are used. FIG. 2 is an explanatory diagram of a filter switching member to be used. FIG. 1A is an arrangement of each filter in the filter slider when the filter slider is used as the filter switching member in the fluorescence endoscope apparatus of FIG. 1, and FIG. The arrangement of each filter in the filter turret when a filter turret is used as a filter switching member in the fluorescence endoscope apparatus, (c) is used as a filter switching member in the fluorescence endoscope apparatus described in Patent Document 1. The arrangement of each filter within the filter turret is shown. It is explanatory drawing which shows optical characteristics, such as a filter used in the fluorescence endoscope apparatus concerning 2nd embodiment of this invention, (a) is the transmittance | permeability of the illumination filter for fluorescence observation, (b) is excitation light cut The transmittance of the filter, (c) shows the transmittance of each filter provided in the mosaic CCD, and (d) shows the wavelength range and intensity of the detected fluorescence and reflected light, respectively. It is a block diagram which shows roughly the whole structure of the fluorescence endoscope apparatus concerning 3rd embodiment of this invention. FIG. 6 is an explanatory diagram showing optical characteristics of a filter or the like used in the fluorescence endoscope apparatus of FIG. 5, (a) is a transmittance of a fluorescence observation illumination filter, (b) is a transmittance of an excitation light cut filter, (c) shows the wavelength transmission state switched by the spectroscopic optical element, and (d) shows the wavelength range and intensity of the detected fluorescence and reflected light, respectively. It is explanatory drawing which shows optical characteristics, such as a filter used in the fluorescence endoscope apparatus concerning 4th embodiment of this invention, (a) is the transmittance | permeability of the illumination filter for fluorescence observation, (b) is excitation light cut The transmittance of the filter, (c) shows the wavelength transmission state switched by the spectroscopic optical element, and (d) shows the wavelength range and intensity of the detected fluorescence and reflected light, respectively.

First Embodiment FIG. 1 is a block diagram schematically showing the overall configuration of a fluorescence endoscope apparatus according to a first embodiment of the present invention. 2A and 2B are explanatory diagrams showing optical characteristics of the filter and the like used in the fluorescence endoscope apparatus of FIG. 1, wherein FIG. 2A is the transmittance of the illumination filter for fluorescence observation, and FIG. 2B is the transmission of the excitation light cut filter. (C) shows the transmittance of each filter provided in the mosaic CCD, and (d) shows the wavelength range and intensity of the detected fluorescence and reflected light, respectively.

  The fluorescence endoscope apparatus according to the first embodiment includes a light source unit 1, an endoscope distal end insertion unit 2, an image processing unit 3, and a display unit 4.

The light source unit 1 includes a light source 11 and a fluorescence observation illumination filter 12.
The light source 11 is configured to emit light in a predetermined wavelength band including an excitation wavelength range and a reflected image acquisition wavelength range.
The fluorescence observation illumination filter 12 includes a transparent member and a film coated on the transparent member. As shown in FIG. 2A, excitation light (460 nm to 500 nm) and reflected image acquisition light ( 650 nm to 670 nm), and has an optical characteristic of blocking light of other wavelengths.

  Moreover, the illumination filter 12 for fluorescence observation is configured to have an optical characteristic that transmits the excitation light and the reflected image acquisition light at an intensity ratio of about 1000: 1, and is reflected by the living tissue 5. As a light intensity adjusting means for adjusting the intensity of the reflected image acquisition light emitted from the light source 11 so that the intensity of the image acquisition light is approximately the same as the intensity of the fluorescence generated from the living tissue 5. It has a function. As used herein, “substantially the same intensity” refers to an intensity that allows a fluorescent image to be clearly distinguished from a reflected image. Therefore, as long as the fluorescent image can be clearly distinguished from the reflected image, the intensity of the reflected image acquisition light may be higher than the intensity of the fluorescent light.

The endoscope distal end insertion portion 2 has an illumination optical system 21 and an imaging optical system 22.
The illumination optical system 21 irradiates the living tissue 5 with light from the light source unit 11 via the light guide 23.

  The light source unit 11, the light guide 23, and the illumination optical system 21 are combined with each other so that the excitation light and the light for obtaining a reflected image having different wavelengths of the excitation light and the fluorescence can be simultaneously formed using a single light source. A function as an illuminating means for irradiating the tissue 5 is provided.

The imaging optical system 22 includes an objective optical system 22a, an imaging optical system 22b, an excitation light cut filter 22c, and an imaging element 22d.
As shown in FIG. 2B, the excitation light cut filter 22c has an optical characteristic of cutting the excitation light (460 nm to 500 nm) and transmitting light of other wavelengths.

The image sensor 22d is composed of a color CCD having a mosaic filter (not shown) and a single-plate image sensor (not shown).
As shown in FIG. 2 (c), the mosaic filter is a filter (not shown) that transmits light in the wavelength range of R (575 nm to 695 nm), and a filter that transmits light in the wavelength range of G (460 nm to 600 nm) ( A filter (not shown) that transmits light in the wavelength region of B (380 nm to 490 nm) is arranged in a mosaic pattern, and the reflected image acquisition light reflected by the living tissue 5 is arranged. It has a function as wavelength separation means for separating the wavelength and the wavelength of the fluorescence generated from the living tissue 5.
The single-plate image sensor is a filter in which each pixel transmits light in the wavelength range of R (575 nm to 695 nm) constituting the mosaic filter, a filter that transmits light in the wavelength range of G (460 nm to 600 nm), and B ( 380 nm to 490 nm) corresponding to a filter that transmits light in a wavelength range, and a reflection image and a fluorescence image separated through a mosaic filter are separately acquired by different pixels.

The image processing unit 3 includes a frame memory 31 and an image processing device 32.
The frame memory 31 includes an R frame memory 31 ₁ , a G frame memory 31 ₂ , and a B frame memory 31 ₃ .
Each of the R frame memory 31 ₁ , the G frame memory 31 ₂ , and the B frame memory 31 ₃ is a filter that transmits light in the R (575 nm to 695 nm) wavelength region constituting the mosaic filter. Corresponding to a filter that transmits light in the wavelength region and a filter that transmits light in the wavelength region of B (380 nm to 490 nm), each image signal separated by the mosaic filter and acquired by each corresponding pixel is separately processed. To remember.
The image processing device 32 combines the image signals stored in the R frame memory 31 ₁ , the G frame memory 31 ₂ , and the B frame memory 31 ₃ . At that time, each image signal is converted into an output signal having a different hue so that a normal tissue portion and a lesion tissue portion can be easily identified.

The display unit 4 displays an image synthesized through the image processing device 32.
The living tissue 5 is labeled with a near-infrared fluorescent agent having an excitation wavelength of 460 nm to 500 nm and a fluorescence wavelength of 500 nm to 600 nm as a fluorescent probe. In FIG. 1, reference numeral 5 a denotes a fluorescent drug accumulation part in the living tissue 5.

  In the fluorescence endoscope apparatus according to the first embodiment configured as described above, the light emitted from the light source 11 and transmitted through the illumination filter 12 for fluorescence observation is guided to the light guide 23 and the distal end of the endoscope distal end insertion portion 2. Is emitted from the illumination optical system 21 to irradiate the living tissue 5. As shown in FIG. 2A, the irradiation light at this time is light in two types of wavelength ranges, that is, excitation light of 460 nm to 500 nm and light for obtaining a reflected image of 650 nm to 670 nm. Further, the reflected image acquisition light of 650 nm to 670 nm is weakened to an intensity of about 1/1000 with respect to the excitation light of 460 nm to 500 nm.

By irradiating the living tissue 5 with this irradiation light, light of the following three wavelength ranges enters the endoscope distal end insertion portion 2 from the living tissue 5.
1-1) Excitation light of 460 nm to 500 nm reflected by the biological tissue 5 1-2) Fluorescence of a fluorescent drug of 500 nm to 600 nm generated from the fluorescent drug accumulation part 5a of the biological tissue 5 by irradiation of excitation light of 460 nm to 500 nm 1-3) Light for obtaining a reflected image of 650 nm to 670 nm reflected by the living tissue 5

  Here, the fluorescence intensity of the fluorescent agent generated in the living tissue 5 of 1-2) is about 1/1000 of the intensity of the excitation light reflected by the living tissue 5 of 1-1). The filter 12 transmits the excitation light and the reflected image acquisition light by adjusting the light intensity so that the intensity ratio is about 1000: 1 before the illumination light is applied to the living tissue 5. . For this reason, the fluorescence intensity of the fluorescent agent generated in the living tissue 5 of 1-2) has the same intensity as the reflected image acquisition light reflected by the living tissue 5 of 1-3).

  The light of 1-1), 1-2), and 1-3) from the biological tissue 5 passes through the objective optical system 22a and the imaging optical system 22b of the endoscope distal end insertion portion 2, and is used as an excitation light cut filter. It enters into 22c. Among the incident light, the excitation light of 1-1) is cut by the excitation light cut filter 22c, and only the fluorescence of 1-2) and the light for acquiring the reflected image of 1-3) pass through the mosaic filter of the color CCD 22d. Then, the image is taken through the image sensor and stored in the frame memory 31.

At that time, the fluorescence of 1-2) is transmitted through a filter that transmits light in the wavelength range of G (460 nm to 600 nm) constituting the mosaic filter, and the light for obtaining a reflected image of 1-3) is transmitted through the mosaic filter. Is transmitted through a filter that transmits light in the wavelength range of R (575 nm to 695 nm).
The single-plate image sensor is a pixel corresponding to a filter that transmits light in a wavelength range of R (575 nm to 695 nm) and a filter that transmits light in a wavelength range of G (460 nm to 600 nm) constituting the mosaic filter. However, the reflected light and fluorescence separated through the mosaic filter are acquired separately.
Further, the frame memory 31 corresponds to a filter that transmits light in a wavelength range of R (575 nm to 695 nm) and a filter that transmits light in a wavelength range of G (460 nm to 600 nm) that constitute the mosaic filter. _1, s G frame memory 31 ₂ husband, separately stored separated corresponding to the image signal of the image signal and the fluorescence of the obtained reflected light each pixel through a mosaic filter.

For this reason, fluorescence and reflected light can be separately detected. Position information of a lesion such as fluorescence from the example cancer G frame memory 31 ₂ 1-2 stored in) are obtained, the biological tissue from the reflected light stored in the R frame memory 31 ₁ 1-3) 5 configuration information is obtained.

Each image signal serving as the information is subjected to predetermined image processing such as image synthesis by the image processing device 32 and displayed on the display unit 4. At that time, the image processing device 32 performs normal tissue portion and lesion tissue portion on the fluorescence image signal stored in the G frame memory 31 ₂ and the reflected light image signal stored in the R frame memory 31 _3. Are converted into output signals having different hues. For example, the position information of the lesion part due to fluorescence stored in the G frame memory 31 ₂ is converted into green, and the morphological information of the living tissue 5 due to reflected light stored in the R frame memory 31 ₃ is converted into red. It may be displayed.

  According to the fluorescence endoscope apparatus of the first embodiment, the light source unit 11 including the illumination filter 12 for fluorescence observation, the light guide 23, and the illumination optical system 21 are combined to use a single light source. Unlike the fluorescence endoscope apparatus of Patent Document 1, the excitation light and the excitation light and fluorescence are simultaneously irradiated onto the living tissue 5 with reflected image acquisition light having different wavelengths. Therefore, it is not necessary to rotate the filter turret in order to repeatedly acquire the turret, and the rotation space for the filter turret is not required. Therefore, the light source unit can be reduced in size.

  Further, according to the fluorescence endoscope apparatus of the first embodiment, the fluorescence observation illumination filter 12 is configured to transmit the excitation light and the reflected image acquisition light at an intensity ratio of about 1000: 1. And the intensity of the reflected image acquisition light emitted from the light source 11 so that the intensity of the reflected image acquisition light reflected by the biological tissue 5 is approximately the same as the intensity of the fluorescence generated from the biological tissue 5. Unlike the fluorescent endoscope apparatus of Patent Document 1, the irradiation time of excitation light for obtaining a fluorescent image by changing the rotational speed of the filter turret is provided. There is no need to adjust the irradiation time of the reflected image acquisition light for obtaining the reflected image.

  Furthermore, according to the fluorescence endoscope apparatus of the first embodiment, the mosaic filter that constitutes the color CCD has the wavelength of the reflected image acquisition light reflected by the living tissue 5 and the wavelength of the fluorescence generated from the living tissue 5. G (460 nm to 600 nm), which has a function as a wavelength separating means, and a single plate type image sensor transmits light in a wavelength region of B (380 nm to 490 nm) constituting each mosaic filter. ) Corresponding to a filter that transmits light in the wavelength range of R, and a filter that transmits light in the wavelength range of R (575 nm to 695 nm), and the reflected image and the fluorescent image separated through the mosaic filter are separated by different pixels. Since it acquires, a fluorescence image and a reflected image can be obtained with high precision.

  For this reason, according to the fluorescence endoscope apparatus of the first embodiment, the light source unit can be reduced in size, and in one observation mode, the acquisition of the morphological information of the living tissue by the reflection image and the lesion part by the fluorescence image can be obtained. The position information can be detected with high accuracy.

  In addition, according to the fluorescence endoscope apparatus of the first embodiment, the morphological information of the living tissue based on the reflection image and the position information of the lesioned part based on the fluorescence image can be acquired simultaneously, and each information is acquired in time series. Since it is not necessary to provide such a configuration, the overall configuration can be simplified.

  Note that the fluorescence endoscope apparatus according to the first embodiment may be configured to be able to switch normal white light observation in addition to the above-described observation using fluorescence and reflected light. In this case, as indicated by a two-dot chain line in FIG. 1, for example, a white light observation filter 13 having an optical characteristic that transmits visible light in a predetermined wavelength band such as 400 nm to 660 nm is replaced with an illumination filter 12 for fluorescence observation. At the same time, it is provided in a filter switching member 14 such as a filter slider 14a shown in FIG. 3A or a filter turret 14b shown in FIG. 3B, and through a filter switching control means 15 for controlling the drive of the filter switching member 14. The light source unit 1 is configured to be switchable for insertion into the optical path. The filter switching control unit 15 also controls the image processing device 32 so that when the white light observation filter 13 is inserted in the optical path, the image processing device 32 adjusts the white balance of the composite image.

  When the filter turret 14a is used as the filter switching member 14, a rotation space for switching between the fluorescence observation illumination filter 12 and the white light observation filter 13 is required. In this case, the filter turret 14a is shown in FIG. As shown in b), the radius around the rotation axis O is sufficient to allow one filter to be arranged. On the other hand, in the fluorescence endoscope apparatus described in Patent Document 1, the filter turret has a radius around the rotation axis O ′ that allows two filters to be arranged, as shown in FIG. Will be necessary and will increase in size.

  The fluorescence endoscope apparatus of the first embodiment is configured so that excitation light and reflected image acquisition light can be obtained simultaneously with a single light source via a fluorescence observation illumination filter. It is not necessary to rotate the filter turret to obtain light for obtaining a reflected image. For this reason, in the fluorescence endoscope apparatus of the first embodiment, even if the filter turret 14a is used as the filter switching member 14 in order to be able to switch between observation with fluorescence and reflected light and observation with normal white light, The fluorescence observation illumination filter 12 and the white light observation filter 13 can be arranged in the circumferential direction around the rotation axis O of the filter turret 14a.

  On the other hand, the fluorescence endoscope apparatus described in Patent Document 1 acquires excitation light and reflected image acquisition light separately with a single light source in accordance with switching between fluorescence observation and observation with normal white light. With this configuration, it is possible to simultaneously obtain excitation light and reflected image acquisition light with a single light source such as the fluorescence observation illumination filter of the fluorescence endoscope apparatus of the first embodiment. I do not have. Moreover, the fluorescence endoscope apparatus described in Patent Document 1 uses a plurality of types of excitation light transmission filters as filters for the fluorescence observation mode and a plurality of types of visible wavelength band transmission filters as the filters for the white light observation mode. In order to obtain excitation light to be acquired separately, light for reflection image acquisition, light of a plurality of types of excitation wavelength regions, or light of a plurality of types of reflection image acquisitions with a single light source, The turret rotation is indispensable. For this reason, in the fluorescence endoscope apparatus described in Patent Document 1, in order to switch between observation with fluorescence and observation with normal white light, a filter for fluorescence observation mode and a filter for white light observation mode are provided. Cannot be arranged in the circumferential direction around the rotation axis O ′ of the filter turret, and must be arranged in the radial direction.

  When the fluorescence endoscope apparatus according to the first embodiment is configured to be able to switch between observation using fluorescence and reflected light and observation using ordinary white light, the white light observation filter 13 provided in the filter switching member 14 is inserted into the optical path. Then, the light emitted from the light source 11 and transmitted through the white light observation filter 13 is guided to the light guide 23 and emitted from the distal end of the endoscope distal end insertion portion 2 to irradiate the living tissue 5. The light reflected by the living tissue 5 enters the excitation light cut filter 22c via the objective optical system 22a and the imaging optical system 22b. Of the incident light, light in the wavelength region of 450 nm to 550 nm is cut by the excitation filter, and other light (400 nm to 450 nm, 550 nm to 660 nm) is transmitted and captured by the color CCD 22d and stored in the frame memory 31. Is done. Next, the image signal stored in the frame memory 31 is subjected to predetermined image processing such as image synthesis by the image processing device 32 and displayed on the display unit 4.

At that time, the light of 400 nm to 450 nm is transmitted through a filter that transmits light in the wavelength range of B (380 nm to 490 nm) constituting the mosaic filter, and the light of 550 nm to 600 nm is R (575 nm to 600 nm) constituting the mosaic filter. 695 nm) is transmitted through a filter that transmits light in the wavelength region.
In addition, the single-plate image sensor is a pixel corresponding to a filter that transmits light in a wavelength range of B (380 nm to 490 nm) and a filter that transmits light in a wavelength range of R (575 nm to 695 nm) that constitutes a mosaic filter. However, 400 nm to 450 nm light and 550 nm to 600 nm light separated through the mosaic filter are separately acquired.
Further, the frame memory 31 corresponds to an R frame memory 31 corresponding to a filter that transmits light in a wavelength range of R (575 nm to 695 nm) and a filter that transmits light in a wavelength range of B (380 nm to 490 nm) constituting the mosaic filter. ₁ , each of the B frame memories 31 ₃ separately stores an image signal of light of 550 nm to 600 nm and an image signal of light of 400 nm to 450 nm acquired by the respective pixels separated through the mosaic filter .

In this case, when the image signals stored in the R frame memory 31 ₁ and the B frame memory 31 ₃ are synthesized as they are, an image in which the wavelength region of 450 nm to 500 nm is cut by the excitation light cut filter 22c is obtained. Adjusts the white balance of the composite image. Thereby, it is possible to obtain an image that is substantially the same as a white image in a general endoscope.

  In the fluorescence endoscope apparatus according to the first embodiment, the illumination filter for fluorescence observation is configured to transmit light of one type of wavelength region as excitation light and reflected image acquisition light, respectively. Alternatively, the filter may be configured as a multiple wavelength extraction filter that transmits plural types of excitation light and reflected image acquisition light. In that case, the mosaic filter and the frame memory may be configured to correspond to each of a plurality of types of fluorescence and reflected image acquisition light.

Second Embodiment FIG. 4 is an explanatory view showing optical characteristics of a filter or the like used in the fluorescence endoscope apparatus according to the second embodiment of the present invention. (A) is the transmittance of the illumination filter for fluorescence observation, (b) shows the transmittance of the excitation light cut filter, (c) shows the transmittance of each filter provided in the mosaic CCD, and (d) shows the wavelength range and intensity of the detected fluorescence and reflected light, respectively. In addition, arrangement | positioning of each member which comprises the fluorescence endoscope apparatus of 2nd embodiment is as substantially the same as the fluorescence endoscope apparatus of 1st embodiment shown in FIG. Here, a different configuration from the fluorescence endoscope apparatus of the first embodiment will be described in detail, and the description of the same configuration will be omitted.

  The fluorescence endoscope apparatus of the second embodiment has a configuration adapted to fluorescence observation using a near-infrared dye that emits fluorescence of 750 nm to 800 nm by irradiation of excitation light of 700 nm to 750 nm as a fluorescent probe.

  Specifically, the fluorescence observation illumination filter 12 includes a transparent member and a film coated on the transparent member. As shown in FIG. 4A, the excitation light (720 nm to 750 nm) and the reflected image are acquired. Of light (400 nm to 550 nm) is transmitted, and light having other wavelengths is blocked.

  The fluorescence observation illumination filter 12 is configured to transmit excitation light and reflected image acquisition light at an intensity ratio of about 1000: 1, as in the fluorescence endoscope apparatus of the first embodiment. The intensity of the reflected image acquisition light emitted from the light source 11 is set so that the intensity of the reflected image acquisition light reflected by the biological tissue 5 is approximately the same as the intensity of the fluorescence generated from the biological tissue 5. It has a function as a light intensity adjusting means to adjust.

  As shown in FIG. 4B, the excitation light cut filter 22c has an optical characteristic of cutting excitation light (720 nm to 750 nm) and transmitting light of other wavelengths.

Similar to the fluorescence endoscope apparatus of the first embodiment, the imaging element 22d is configured by a color CCD including a mosaic filter (not shown) and a single-plate image sensor (not shown).
As shown in FIG. 4 (c), the mosaic filter is a filter (not shown) that transmits light in the wavelength region of R (575 nm to 775 nm), and a filter that transmits light in the wavelength region of G (460 nm to 600 nm) ( A filter (not shown) that transmits light in the wavelength region of B (380 nm to 490 nm) is arranged in a mosaic pattern, and the reflected image acquisition light reflected by the living tissue 5 is arranged. It has a function as wavelength separation means for separating the wavelength and the wavelength of the fluorescence generated from the living tissue 5.
The single-plate image sensor is a filter in which each pixel transmits light in a wavelength range of R (575 nm to 775 nm) constituting the mosaic filter, a filter that transmits light in a wavelength range of G (460 nm to 600 nm), and B ( 380 nm to 490 nm) corresponding to a filter that transmits light in a wavelength range, and a reflection image and a fluorescence image separated through a mosaic filter are separately acquired by different pixels.

The image processing unit 3 includes a frame memory 31 and an image processing device 32.
The frame memory 31 includes an R frame memory 31 ₁ , a G frame memory 31 ₂ , and a B frame memory 31 ₃ .
Each of the R frame memory 31 ₁ , the G frame memory 31 ₂ , and the B frame memory 31 ₃ is a filter that transmits light in a wavelength region of R (575 nm to 775 nm) that constitutes the mosaic filter. Corresponding to a filter that transmits light in the wavelength region and a filter that transmits light in the wavelength region of B (380 nm to 490 nm), each image signal separated by the mosaic filter and acquired by each corresponding pixel is separately processed. To remember.

Other configurations are substantially the same as those of the fluorescence endoscope apparatus of the first embodiment.
The living tissue 5 is labeled as a fluorescent probe with a near-infrared fluorescent agent having an excitation wavelength of 700 nm to 750 nm and a fluorescence wavelength of 750 nm to 800 nm.

  In the fluorescence endoscope apparatus of the second embodiment configured as described above, the light emitted from the light source 11 and transmitted through the fluorescence observation illumination filter 12 is guided to the light guide 23, and the distal end of the endoscope distal end insertion portion 2 is guided. Is emitted from the illumination optical system 21 to irradiate the living tissue 5. As shown in FIG. 4A, the irradiation light at this time is light in two types of wavelength regions, that is, a reflection image acquisition light of 400 nm to 550 nm and an excitation light of 720 nm to 750 nm. In addition, the reflected image acquisition light of 400 nm to 550 nm is weakened to an intensity of about 1/1000 with respect to the excitation light of 720 nm to 750 nm.

By irradiating the living tissue 5 with this irradiation light, light of the following three wavelength ranges enters the endoscope distal end insertion portion 2 from the living tissue 5.
2-1) Light for reflection image acquisition of 400 nm to 550 nm reflected by the biological tissue 5 2-2) Excitation light of 720 nm to 750 nm reflected by the biological tissue 5 2-3) By irradiation of excitation light of 720 nm to 750 nm, Fluorescence of a fluorescent drug of 750 nm to 800 nm generated from the fluorescent drug accumulation part 5a of the living tissue 5

  Here, the fluorescence intensity of the fluorescent agent generated in the living tissue 5 of 2-3) is about 1/1000 of the intensity of the excitation light reflected by the living tissue 5 of 2-2). The filter 12 transmits the excitation light and the reflected image acquisition light by adjusting the light intensity so that the intensity ratio is about 1000: 1 before the illumination light is applied to the living tissue 5. . For this reason, the fluorescence intensity of the fluorescent agent generated in the biological tissue 5 of 2-3) is the same intensity as the reflected image acquisition light reflected by the biological tissue 5 of 2-1).

  The light of 2-1), 2-2), and 2-3) from the living tissue 5 passes through the objective optical system 22a and the imaging optical system 22b of the endoscope distal end insertion portion 2, and is used as an excitation light cut filter. It enters into 22c. Of the incident light, the excitation light of 2-2) is cut by the excitation light cut filter 22c, and only the fluorescence for 2-3) and the reflected image acquisition light of 2-1) pass through the mosaic filter of the color CCD 22d. Then, the image is taken through the image sensor and stored in the frame memory 31.

At that time, among the fluorescence of 2-3), light of 750 nm to 775 nm is transmitted through a filter that transmits light in the wavelength range of R (575 nm to 775 nm) constituting the mosaic filter, and the reflected image of 2-1) The light for acquisition passes through a filter that transmits light in a wavelength range of G (460 nm to 600 nm) or a filter that transmits light in a wavelength range of B (380 nm to 490 nm) constituting the mosaic filter.
In addition, the single-plate image sensor includes a filter that transmits light in a wavelength range of R (575 nm to 775 nm) constituting a mosaic filter, a filter that transmits light in a wavelength range of G (460 nm to 600 nm), and B (380 nm to 490 nm). ) Each pixel corresponding to a filter that transmits light in the wavelength region separately acquires fluorescence and reflected light separated through the mosaic filter.
Further, the frame memory 31 includes a filter that transmits light in a wavelength region of R (575 nm to 775 nm) constituting the mosaic filter, a filter that transmits light in a wavelength region of G (460 nm to 600 nm), and B (380 nm to 490 nm). Each of the R frame memory 31 ₁ , the G frame memory 31 ₂ , and the B frame memory 31 ₃ corresponding to the filter that transmits light in the wavelength region of the light is separated through the mosaic filter and acquired by the corresponding pixels. The image signal and the reflected light image signal are stored separately.

For this reason, fluorescence and reflected image acquisition light can be detected separately. By the way, blood mainly has a characteristic of absorbing light in a wavelength range of 400 nm to 500 nm. For this reason, among the reflected light of 2-1), from 500 nm to 550 nm light stored in the G frame memory 31 ₂ , the morphological information of the living tissue 5 and 400 nm to 500 nm light stored in the B frame memory 31 ₃ The blood flow information of the living tissue 5 can be obtained from the fluorescence, and the position information of the lesioned part such as cancer can be obtained from the fluorescence 2-3) stored in the R frame memory 31 ₁ .

Each image signal serving as the information is subjected to predetermined image processing such as image synthesis by the image processing device 32 and displayed on the display unit 4.
Other operations and effects are substantially the same as those of the fluorescence endoscope apparatus of the first embodiment.

Third Embodiment FIG. 5 is a block diagram schematically showing the overall configuration of a fluorescence endoscope apparatus according to a third embodiment of the present invention. 6A and 6B are explanatory views showing optical characteristics of the filter and the like used in the fluorescence endoscope apparatus of FIG. 5, where FIG. 6A is the transmittance of the illumination filter for fluorescence observation, and FIG. 6B is the transmission of the excitation light cut filter. (C) shows the wavelength transmission state switched by the spectroscopic optical element, and (d) shows the wavelength range and intensity of the detected fluorescence and reflected light, respectively.

In the fluorescence endoscope apparatus of the third embodiment, the wavelength separating means is constituted by the spectroscopic optical element 22e, and the imaging element 22d ′ is constituted by a monochromatic CCD.
Specifically, the imaging optical system 22 includes an objective optical system 22a, an imaging optical system 22b, an excitation light cut filter 22c, a spectroscopic optical element 22e, and an imaging element 22d ′. A spectroscopic optical element control unit 22f is connected to the spectroscopic optical element 22e and the image processing unit 3.
The spectroscopic optical element 22e is made of an etalon, and transmits light in a wavelength range of 500 nm to 600 nm with a central wavelength of 530 nm as a transmittance peak, as shown in FIG. 6C, through the spectroscopic optical element control unit 22f. Control is performed so that the switching between the two wavelength transmission states, that is, the first wavelength transmission state and the second wavelength transmission state that transmits light in the wavelength region of 600 nm to 700 nm with 660 nm as a transmission peak, can be repeated. Has been.
Note that etalon uses light interference and can change the wavelength of light that can be transmitted or reflected by changing the distance between a pair of mirror surfaces arranged to face each other. It is a variable rate element.

  The spectroscopic optical element control unit 22f controls the driving of the spectroscopic optical element 22e, such as the wavelength transmission state (transmission wavelength range) and the transmission wavelength state switching pitch of the spectroscopic optical element 22e, and the image processing device 32 in the image processing unit 3. The timing of the image processing by the image processing device 32 is controlled, and an image is sent to the image processing device 32 every time one set of transmission wavelength states in the spectroscopic optical element 22e is switched (in the example of FIG. 6, every two types of transmission wavelength states are switched). Processing is performed (for example, an image processing instruction signal is transmitted).

The image sensor 22d ′ is composed of a single color CCD composed of a single plate image sensor (not shown).
The single-plate image sensor corresponds to two types of wavelength transmission states in which all the pixels are switched in the spectroscopic optical element 22e, and takes an image in time series every time the wavelength transmission state is switched. The reflection image and the fluorescence image separated through 22e are acquired separately.

The image processing unit 3 includes a frame memory 31 ′ and an image processing device 32.
The frame memory 31 ′ includes a first frame memory 31 ₁ ′, a second frame memory 31 ₂ ′, and a third frame memory 31 ₃ ′.
The first frame memory 31 ₁ ′, the second frame memory 31 ₂ ′, and the third frame memory 31 ₃ ′ correspond to two types of wavelength transmission states that are switched in the spectroscopic optical element 22e, and the wavelength transmission state is switched off. Each time the signal is changed, each image signal picked up by all the pixels in the single-plate image sensor in time series is stored separately.

The image processing device 32 controls the first frame memory 31 ₁ ′, the second frame memory 31 ₂ ′, and the third frame through the control of the spectroscopic optical element control unit 22f (for example, every time an image processing instruction signal is received). The image signals stored in the frame memory 31 ₃ ′ are synthesized. At that time, each image signal is converted into an output signal having a different hue so that a normal tissue portion and a lesion tissue portion can be easily identified.

Other configurations are substantially the same as those of the fluorescence endoscope apparatus of the first embodiment.
The living tissue 5 is labeled with a near-infrared fluorescent agent having an excitation wavelength of 460 nm to 500 nm and a fluorescence wavelength of 500 nm to 600 nm as a fluorescent probe. In FIG. 5, reference numeral 5 a denotes a fluorescent drug accumulation part in the living tissue 5.

  In the fluorescence endoscope apparatus of the third embodiment configured as described above, the spectroscopic optical element 22e has two types of transmittance peaks at the center wavelengths of 530 nm and 660 nm as shown in FIG. The switching of the wavelength transmission state is repeated, and all the pixels in the single-plate image sensor constituting the imaging element 22d ′ correspond to the two types of wavelength transmission states in the spectroscopic optical element 22e. Since images of light transmitted through the optical element 22e are captured in time series, a fluorescent image of 500 nm to 600 nm and a reflected image of 650 nm to 670 nm can be acquired separately.

  Specifically, in the fluorescence endoscope apparatus of the third embodiment, the light emitted from the light source 11 and transmitted through the fluorescence observation illumination filter 12 is guided to the light guide 23, and the illumination optics at the distal end of the endoscope distal end insertion portion 2 is obtained. The light is emitted from the system 21 to irradiate the living tissue 5. The irradiation light at this time is the same light as that of the fluorescence endoscope apparatus of the first embodiment. As shown in FIG. 6A, the excitation light of 460 nm to 500 nm and the reflected image acquisition of 650 nm to 670 nm are obtained. It is light of two types of wavelength regions. In addition, the reflected image acquisition light of 650 nm to 670 nm is weakened to an intensity of about 1/1000 with respect to the excitation light of 460 nm to 500 nm.

By irradiating the living tissue 5 with this irradiation light, light of the following three wavelength ranges enters the endoscope distal end insertion portion 2 from the living tissue 5.
3-1) Excitation light of 460 nm to 500 nm reflected by the biological tissue 5 3-2) Fluorescence of the fluorescent drug of 500 nm to 600 nm generated from the fluorescent drug accumulation part 5a of the biological tissue 5 by irradiation of excitation light of 460 nm to 500 nm 3-3) Light for obtaining a reflected image of 650 nm to 670 nm reflected by the living tissue 5

  Here, the fluorescence intensity of the fluorescent agent generated in the biological tissue 5 of 3-2) is about 1/1000 of the intensity of the excitation light reflected by the biological tissue 5 of 3-1). The filter 12 transmits the excitation light and the reflected image acquisition light by adjusting the light intensity so that the intensity ratio is about 1000: 1 before the illumination light is applied to the living tissue 5. . For this reason, the fluorescence intensity of the fluorescent agent generated in the living tissue 5 of 3-2) has the same intensity as the reflected image acquisition light reflected by the living tissue 5 of 3-3).

  The light of 3-1), 3-2), and 3-3) from the biological tissue 5 passes through the objective optical system 22a and the imaging optical system 22b of the endoscope distal end insertion portion 2, and is used as an excitation light cut filter. It enters into 22c. Of the incident light, the excitation light of 3-1) is cut by the excitation light cut filter 22c, and only the fluorescence for acquiring the reflected image of 3-3) and 3-3) enters the spectroscopic optical element 22e. The light of a predetermined wavelength range selected according to the two types of wavelength transmission states switched in the spectroscopic optical element 22e is transmitted through the spectroscopic optical element 22e, is imaged via the image sensor of the monochrome CCD 22d ′, and is stored in the frame memory 31. Remembered.

At that time, since the spectroscopic optical element 22e can transmit light in the wavelength range of 500 nm to 600 nm with the central wavelength of 530 nm as the peak of transmittance in the first wavelength transmission state, the fluorescence of 3-2) is transmitted. Make it transparent. When the spectroscopic optical element 22e is in the second wavelength transmission state, light in the wavelength range of 600 nm to 700 nm can be transmitted with the central wavelength of 660 nm as the peak of transmittance, and thus the light for acquiring the reflected image of 3-3) Permeate.
In addition, the single-plate image sensor corresponds to two types of wavelength transmission states in which all pixels are switched in the spectroscopic optical element 22e, and images of fluorescence and reflected light are acquired in time series every time the wavelength transmission state is switched. To do.
Further, the frame memory 31 ′ supports two types of wavelength transmission states in which the first frame memory 31 ₁ ′, the second frame memory 31 ₂ ′, and the third frame memory 31 ₃ ′ are switched in the spectroscopic optical element 22e. Then, every time the wavelength transmission state is switched, the fluorescence image signal and the reflected light image signal acquired by all the pixels in the single-plate image sensor are stored in time series.

For this reason, fluorescence and reflected image acquisition light can be detected separately. When the spectroscopic optical element 22e is in the first wavelength transmission state, position information of a lesion such as cancer is obtained by fluorescence from the fluorescent dye 3-2) stored in the frame memory 31 _n ′, and the spectroscopic optical element When 22e is in the second wavelength transmission state, the morphological information of the living tissue 5 by the reflected light of 3-3) is obtained.

The image signals serving as the respective information are subjected to predetermined image processing such as image synthesis by the image processing device 32 and displayed on the display unit 4. At that time, the image processing device 32 distinguishes between the normal tissue portion and the lesion tissue portion with respect to the fluorescence image signal and the reflected light image signal stored in each frame memory 31 _n ′ (n: 1 to 3). In order to facilitate the conversion, the output signal is converted into an output signal having a different hue. For example, the position information of the lesion part by fluorescence stored in the first frame memory 31 ₁ ′ is converted into green, and the morphological information of the living tissue 5 by reflected light stored in the second frame memory 31 ₂ ′ is converted into red, It may be displayed on the display unit 4.

According to the fluorescence endoscope apparatus of the third embodiment, the spectral optical element 22e switches the wavelength transmission state, and each time the spectral transmission state of the spectral optical element 22e is switched, an image of light transmitted through the spectral optical element 22e is displayed. Since the image pickup element 22d ′ picks up images in time series, the reflection image and the fluorescence image can be acquired separately. Moreover, unlike the filter turret used in the fluorescence endoscope apparatus described in Patent Document 1, the spectroscopic optical element 22e can be switched at high speed at an arbitrary pitch, and the switching speed can be adjusted with high accuracy. can do. For this reason, a fluorescence image and a reflected image can be obtained with high accuracy.
Other effects are substantially the same as those of the fluorescence endoscope apparatus of the first embodiment.

  Note that the fluorescence endoscope apparatus according to the third embodiment may be configured so that normal white light observation can be switched in addition to the above-described observation using fluorescence and reflected light. In this case, as indicated by a two-dot chain line in FIG. 5, for example, the white light observation filter 13 having optical characteristics that transmits visible light in a predetermined wavelength band such as 400 nm to 660 nm is used as the fluorescence observation illumination filter 12. At the same time, it is provided in a filter switching member 14 such as a filter slider 14a shown in FIG. 3A or a filter turret 14b shown in FIG. 3B, and through a filter switching control means 15 for controlling the drive of the filter switching member 14. The light source unit 1 is configured to be switchable for insertion into the optical path. The filter switching control unit 15 also controls the image processing device 32 so that when the white light observation filter 13 is inserted in the optical path, the image processing device 32 adjusts the white balance of the composite image.

  In addition, the spectroscopic optical element control unit 22f synchronizes with the filter switching control of the filter switching control means 15 so that the spectroscopic optical element 22e has a wavelength region of 600 nm to 700 nm (with R of the center wavelength of 640 nm, for example). A first wavelength transmission state that transmits light in a wavelength region), and a second wavelength transmission state that transmits light in a wavelength region of 500 nm to 600 nm (G wavelength region) with a central wavelength of 540 nm as a transmittance peak, Control is performed so that switching of three types of wavelength transmission states of the third wavelength transmission state that transmits light in a wavelength region of 400 nm to 500 nm (B wavelength region) with a central wavelength of 440 nm as a transmittance peak can be repeated. .

  When the fluorescence endoscope apparatus of the third embodiment is configured to be able to switch between observation with fluorescence and reflected light and observation with normal white light, the white light observation filter 13 provided in the filter switching member 14 is inserted into the optical path. Then, the light emitted from the light source 11 and transmitted through the white light observation filter 13 is guided to the light guide 23 and emitted from the distal end of the endoscope distal end insertion portion 2 to irradiate the living tissue 5. The light reflected by the living tissue 5 enters the excitation light cut filter 22c via the objective optical system 22a and the imaging optical system 22b. Of the incident light, light in the wavelength region of 450 nm to 550 nm is cut by the excitation filter, and other light (400 nm to 450 nm, 550 nm to 660 nm) is transmitted and incident on the spectroscopic optical element 22e. Light in a predetermined wavelength range selected according to the three types of wavelength transmission states switched in 22e is transmitted through the spectroscopic optical element 22e, captured through the image sensor of the monochrome CCD 22d ', and stored in the frame memory 31'. . Next, the image signal stored in the frame memory 31 ′ is subjected to predetermined image processing such as image synthesis by the image processing device 32 and displayed on the display unit 4.

At that time, since the spectroscopic optical element 22e can transmit light in a wavelength region of 600 nm to 700 nm (wavelength region of R) with a central wavelength of 640 nm as a transmittance peak when in the first wavelength transmission state, 600 nm Transmits light in the wavelength region of ˜660 nm. When the spectroscopic optical element 22e is in the second wavelength transmission state, light in the wavelength range of 500 nm to 600 nm (G wavelength range) can be transmitted with the central wavelength of 540 nm as the peak of transmittance, so that the wavelength of 550 nm to 600 nm Transmits light in the area. When the spectroscopic optical element 22e is in the third wavelength transmission state, it can transmit light in a wavelength range of 400 nm to 500 nm (wavelength range of B) with a central wavelength of 440 nm as a peak of transmittance, and thus a wavelength of 400 nm to 450 nm. Transmits light in the area.
The single-plate image sensor corresponds to three types of wavelength transmission states in which all the pixels are switched in the spectroscopic optical element 22e, and each time the wavelength transmission state is switched, an image of R (600 nm to 660 nm), G (550 nm). To 600) and B (400 to 450 nm) are acquired in time series.
Further, the frame memory 31 ′ supports three types of wavelength transmission states in which the first frame memory 31 ₁ ′, the second frame memory 31 ₂ ′, and the third frame memory 31 ₃ ′ are switched in the spectroscopic optical element 22e. Then, every time the wavelength transmission state is switched, R, G, and B image signals acquired by all the pixels in the single-plate image sensor are stored in time series.

In this case, if the image signals stored in the first frame memory 31 ₁ ′, the second frame memory 31 ₂ ′, and the third frame memory 31 ₃ ′ are synthesized as they are, a wavelength region of 450 nm to 500 nm is generated by the excitation light cut filter 22c. Although the image is cut, the image processing device 32 adjusts the white balance of the composite image. Thereby, it is possible to obtain an image that is substantially the same as a white image in a general endoscope.

  In the fluorescence endoscope apparatus according to the third embodiment, the fluorescence observation illumination filter is configured to transmit light of one type of wavelength region as excitation light and reflected image acquisition light, respectively. A plurality of types of excitation light and reflected image acquisition light may be transmitted. In that case, the spectroscopic optical element 22e and the spectroscopic optical element control unit 22f may be configured to switch to a plurality of wavelength transmission states corresponding to a plurality of types of fluorescence and reflected image acquisition light.

  In addition, in the fluorescence endoscope apparatus according to the third embodiment, a reflected image obtained by the light source 11 having a wavelength with the maximum transmittance that allows the spectroscopic optical element 22e to pass as reflected image obtaining light reflected by the living tissue 5 is obtained. It is good also as a structure which can adjust so that it may shift | deviate from the wavelength of the maximum intensity | strength in the light for use. For example, as indicated by a two-dot chain line in FIG. 6 (c), the peak wavelength of the transmittance in the second wavelength transmission state is shifted by a predetermined amount from 660 nm, and the reflected image acquisition light transmitted through the spectroscopic optical element 22e is transmitted. Adjust the transmittance. In this way, the fluorescence observation illumination filter 12 need not be configured so that the excitation light and the reflected image acquisition light are transmitted with a precise intensity ratio. That is, the spectroscopic optical element 22e functions as a light intensity adjusting means, and the intensity of the reflected image acquisition light reflected by the living tissue 5 can be adjusted to be approximately the same as the intensity of the fluorescence generated from the living tissue 5. . Thereby, the structure of the illumination filter for fluorescence observation can be simplified, and the cost of the whole apparatus can be reduced.

Fourth Embodiment FIG. 7 is an explanatory view showing optical characteristics of a filter or the like used in the fluorescence endoscope apparatus according to the fourth embodiment of the present invention, and (a) shows the transmittance of the illumination filter for fluorescence observation, (b) shows the transmittance of the excitation light cut filter, (c) shows the wavelength transmission state switched by the spectroscopic optical element, and (d) shows the wavelength range and intensity of the detected fluorescence and reflected light, respectively. In addition, arrangement | positioning of each member which comprises the fluorescence endoscope apparatus of 4th embodiment is substantially the same as the fluorescence endoscope apparatus of 3rd embodiment shown in FIG. Here, a different configuration from the fluorescence endoscope apparatus of the third embodiment will be described in detail, and the description of the same configuration will be omitted.

  The fluorescence endoscope apparatus of the fourth embodiment has a configuration adapted to fluorescence observation using a near-infrared dye that emits fluorescence of 750 nm to 800 nm by irradiation of excitation light of 700 nm to 750 nm as a fluorescent probe.

  Specifically, the illumination filter 12 for fluorescence observation includes a transparent member and a film coated on the transparent member. As shown in FIG. 7A, the excitation light (720 nm to 750 nm) and the reflected image are acquired. Of light (400 nm to 550 nm) is transmitted, and light having other wavelengths is blocked.

  The fluorescence observation illumination filter 12 is configured to transmit excitation light and reflected image acquisition light at an intensity ratio of about 1000: 1, as in the fluorescence endoscope apparatus of the first embodiment. The intensity of the reflected image acquisition light emitted from the light source 11 is set so that the intensity of the reflected image acquisition light reflected by the biological tissue 5 is approximately the same as the intensity of the fluorescence generated from the biological tissue 5. It has a function as a light intensity adjusting means to adjust.

  As shown in FIG. 7B, the excitation light cut filter 22c has an optical characteristic that cuts excitation light (720 nm to 75 nm) and transmits light of other wavelengths.

  The spectroscopic optical element 22e is made of an etalon, and transmits light in a wavelength region of 400 nm to 450 nm with a center wavelength of 420 nm as a transmittance peak as shown in FIG. 7C via the spectroscopic optical element control unit 22f. A first wavelength transmission state, a second wavelength transmission state that transmits light in a wavelength range of 500 nm to 600 nm with a transmission peak of 540 nm, and light in a wavelength range of 700 nm to 800 nm with a transmission peak of 770 nm. The third wavelength transmission state to be transmitted and the three types of wavelength transmission states can be repeatedly switched.

  The spectroscopic optical element control unit 22f controls the driving of the spectroscopic optical element 22e, such as the wavelength transmission state (transmission wavelength range) and the transmission wavelength state switching pitch of the spectroscopic optical element 22e, and the image processing device 32 in the image processing unit 3. The image processing timing is controlled by the image processing device 32, and the image processing device 32 receives an image every time one set of transmission wavelength states in the spectroscopic optical element 22e is switched (in the example of FIG. 7, each time three types of transmission wavelength states are switched). Processing is performed (for example, an image processing instruction signal is transmitted).

Other configurations are substantially the same as those of the fluorescence endoscope apparatus according to the third embodiment.
The living tissue 5 is labeled with a near-infrared fluorescent agent having an excitation wavelength of 720 nm to 750 nm and a fluorescence wavelength of 750 nm to 800 nm as a fluorescent probe.

  In the fluorescence endoscope apparatus of the fourth embodiment configured as described above, the spectroscopic optical element 22e has the transmittance peaks at the center wavelengths of 420 nm, 540 nm, and 770 nm, as shown in FIG. 7C. Each time the wavelength transmission state is changed, all the pixels in the single-plate image sensor constituting the imaging element 22d ′ correspond to the three types of wavelength transmission states in the spectroscopic optical element 22e, and the wavelength transmission state is switched. In addition, since images of light transmitted through the spectroscopic optical element 22e are captured in time series, a reflection image of 400 nm to 450 nm, a reflection image of 500 nm to 550 nm, and a fluorescence image of 750 nm to 800 nm can be separately acquired.

  Specifically, in the fluorescence endoscope apparatus of the fourth embodiment, the light emitted from the light source 11 and transmitted through the fluorescence observation illumination filter 12 is guided to the light guide 23 and emitted from the distal end of the endoscope distal end insertion portion 2. Then, the living tissue 5 is irradiated. The irradiation light at this time is the same light as that of the fluorescence endoscope apparatus of the second embodiment. As shown in FIG. 7A, the light for obtaining a reflection image of 400 nm to 550 nm, the excitation of 720 nm to 750 nm Light of two types of wavelength ranges. In addition, the reflected image acquisition light of 400 nm to 550 nm is weakened to an intensity of about 1/1000 of the excitation light of 720 nm to 750 nm.

By irradiating the living tissue 5 with this irradiation light, light of the following three wavelength ranges enters the endoscope distal end insertion portion 2 from the living tissue 5.
4-1) Light for acquiring a reflected image of 400 nm to 550 nm reflected by the biological tissue 5 4-2) Excitation light of 720 nm to 750 nm reflected by the biological tissue 5 4-3) By irradiation with excitation light of 720 nm to 750 nm, Fluorescence of a fluorescent drug having a fluorescence of 750 nm to 800 nm generated from the fluorescent drug accumulation part 5a of the living tissue 5

  Here, the fluorescence intensity of the fluorescent agent generated in the biological tissue 5 of 4-3) is about 1/1000 of the intensity of the excitation light reflected by the biological tissue 5 of 4-2). The filter 12 transmits the excitation light and the reflected image acquisition light by adjusting the light intensity so that the intensity ratio is about 1000: 1 before the illumination light is applied to the living tissue 5. . For this reason, the fluorescence intensity of the fluorescent agent generated in the biological tissue 5 of 4-3) is the same intensity as the reflected image acquisition light reflected by the biological tissue 5 of 4-1).

  The light of 4-1), 4-2), and 4-3) from the living tissue 5 passes through the objective optical system 22a and the imaging optical system 22b of the endoscope distal end insertion portion 2, and is excited light cut filter. It enters into 22c. Of the incident light, the excitation light of 4-2) is cut by the excitation light cut filter 22c, and only the light for acquiring the reflected image of 4-1) is incident on the spectroscopic optical element 22e. The light in a predetermined wavelength range selected according to the three types of wavelength transmission states switched in the spectroscopic optical element 22e is transmitted through the spectroscopic optical element 22e, and is imaged through the image sensor of the monochrome CCD 22d ′, and is stored in the frame memory 31. Remembered.

At that time, the spectroscopic optical element 22e can transmit light in the wavelength range of 400 nm to 450 nm with the central wavelength of 420 nm as the peak of transmittance when in the first wavelength transmission state, and thus the reflected image of 4-1). Of the light for acquisition, light of 400 nm to 450 nm is transmitted. When the spectroscopic optical element 22e is in the second wavelength transmission state, light in the wavelength range of 500 nm to 600 nm can be transmitted with the central wavelength of 540 nm as the peak of transmittance, so that light for obtaining a reflected image in 4-1) is obtained. Among them, light of 500 nm to 550 nm is transmitted. When the spectroscopic optical element 22e is in the third wavelength transmission state, light in the wavelength region of 700 nm to 800 nm can be transmitted with the center wavelength of 770 nm as the peak of transmittance, and therefore the fluorescence of 4-2) is transmitted.
In addition, the single-plate image sensor corresponds to three types of wavelength transmission states in which all pixels are switched in the spectroscopic optical element 22e, and images of fluorescence and reflected light are acquired in time series each time the wavelength transmission state is switched. To do.
Further, the frame memory 31 ′ supports three types of wavelength transmission states in which the first frame memory 31 ₁ ′, the second frame memory 31 ₂ ′, and the third frame memory 31 ₃ ′ are switched in the spectroscopic optical element 22e. Then, every time the wavelength transmission state is switched, the fluorescence image signal and the reflected light image signal acquired by all the pixels in the single-plate image sensor are stored in time series.

For this reason, fluorescence and reflected image acquisition light can be detected separately. As described above, blood mainly has a characteristic of absorbing light in the wavelength range of 400 nm to 450 nm. For this reason, when the spectroscopic optical element 22e is in the first wavelength transmission state, blood flow information of the living tissue 5 from 400 nm to 450 nm light stored in the first frame memory 31 ₁ ′ among the reflected light of 4-1). When the spectroscopic optical element 22e is in the second wavelength transmission state, the morphological information of the living tissue 5 is obtained from the light of 500 nm to 550 nm stored in the second frame memory 31 ₂ ′ among the reflected light of 4-1). When the spectroscopic optical element 22e is in the third wavelength transmission state, position information of a lesioned part such as cancer is obtained from the fluorescence 4-3) stored in the third frame memory 31 ₃ ′.

Each image signal serving as the information is subjected to predetermined image processing such as image synthesis by the image processing device 32 and displayed on the display unit 4.
Other operations and effects are substantially the same as those of the fluorescence endoscope apparatus of the third embodiment.

  INDUSTRIAL APPLICABILITY The fluorescence endoscope apparatus of the present invention is useful for a fluorescence endoscope apparatus that acquires position information of a lesioned part in a living tissue by a fluorescence image and morphological information of the living tissue by a reflection image.

DESCRIPTION OF SYMBOLS 1 Light source part 11 Light source 12 Illumination filter 2 for fluorescence observation End endoscope insertion part 21 Illumination optical system 22 Imaging optical system 22a Objective optical system 22b Imaging optical system 22c Excitation light cut filters 22d and 22d 'Imaging element 22e Spectroscopic optical element 22f Spectroscopic optical element control unit 23 Light guide 3 Image processing unit 31, 31 ′ Frame memory 31 ₁ R frame memory 31 ₂ G frame memory 31 ₃ B frame memory 31 ₁ ′ First frame memory 31 ₂ ′ Second frame memory 31 ₃ 'Third frame memory 32 Image processing device 4 Display unit 5 Biological tissue 5a Fluorescent drug accumulating unit

Claims (5)

Irradiating excitation light and reflected image acquisition light to a biological tissue, and using the fluorescence generated from the biological tissue and the reflected image acquisition light reflected by the biological tissue, the position of a lesion in the biological tissue And a fluorescence endoscope apparatus for observing the morphology of the living tissue,
Illumination means configured to irradiate the living tissue with the excitation light and the reflected image acquisition light having different wavelengths from the excitation light and the fluorescence using one light source,
The reflected image acquisition light emitted from the light source or the light so that the intensity of the reflected image acquisition light reflected by the biological tissue is substantially the same as the intensity of the fluorescence generated from the biological tissue. Light intensity adjusting means for adjusting the intensity of the reflected image acquisition light reflected by the living tissue;
An excitation cut filter for cutting the excitation light reflected by the living tissue;
Wavelength separation means for separating the wavelength of the reflected image acquisition light reflected from the biological tissue and the wavelength of the fluorescence generated from the biological tissue;
A fluorescence endoscope apparatus comprising: an imaging unit that separately obtains a reflection image and a fluorescence image separated through the wavelength separation unit. A mosaic having a reflection image acquisition wavelength transmission region that transmits the wavelength of the reflected image acquisition light reflected by the biological tissue and a fluorescence wavelength transmission region that transmits the fluorescence wavelength generated from the biological tissue in a mosaic pattern It has a color CCD consisting of a filter and a single-plate image sensor,
The wavelength separation means comprises the mosaic filter;
2. The fluorescence endoscope apparatus according to claim 1, wherein the imaging unit includes pixels corresponding to mosaic areas of the mosaic filter in the single-plate image sensor. Equipped with a single color CCD consisting of a single-plate image sensor,
The wavelength separation means comprises a spectroscopic optical element that switches the wavelength of the reflected image acquisition light reflected by the living tissue and the wavelength of the fluorescence generated from the living tissue in a time-sharing manner, and transmits it.
The fluorescence endoscope apparatus according to claim 1, wherein the imaging unit includes all pixels in the single-plate image sensor. The irradiating means includes a multiple wavelength extraction filter that simultaneously extracts the excitation light and the light for reflection image acquisition having different wavelengths from the excitation light and the fluorescence from the light emitted from the light source,
The fluorescence endoscope apparatus according to any one of claims 1 to 3, wherein the light intensity adjusting unit includes the multiple wavelength extraction filter. The spectroscopic optical element is configured such that the wavelength of the maximum transmittance that is transmitted as the reflected image acquisition light reflected by the biological tissue is shifted from the maximum intensity wavelength of the reflected image acquisition light emitted from the light source. Configured,
The fluorescence endoscope apparatus according to claim 3, wherein the light intensity adjusting unit includes the spectroscopic optical element.

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