JP5114003B2 - Fluorescence endoscope device - Google Patents

Description

The present invention performs fluorescence observation in a body cavity, relates to a fluorescent endoscopic KagamiSo location for detecting the residue of the body cavity.

2. Description of the Related Art In recent years, endoscopes that can optically inspect a body cavity or perform treatment using a treatment tool as necessary have come to be widely used in the medical field.
Further, in addition to the case of performing an endoscopic examination in a normal visible region, it has come to be used when performing an endoscopic examination using a fluorescence image using fluorescence.
As conventional examples, for example, Japanese Patent Application Laid-Open No. 7-155285 and Japanese Patent Application Laid-Open No. 8-224208 disclose a fluorescence endoscope apparatus capable of obtaining a fluorescent image.

When performing endoscopy using fluorescence, when a fluorescent agent that easily accumulates in a lesion is administered to a patient, etc., and the inside of a body cavity of the patient, such as the digestive tract, is examined with a fluorescence endoscope, the residue also becomes fluorescent. As a result, the influence of the residue may increase. In addition, it cannot be determined on the fluorescence image whether the fluorescence-emitting portion in the observed fluorescence image is due to the fluorescence agent accumulated in the lesion or due to the residue.
For this reason, it is very useful to be able to identify and display whether the fluorescence emitting portion in the fluorescence image is due to the fluorescent agent accumulated in the lesion or due to the residue . In addition, the fluorescent image portion due to the residue may interfere with the observation with the fluorescent image.

  In the above conventional example, endoscopy can be performed with a fluorescence image. However, when a residue is mixed in the fluorescence image, it is determined whether the residue is due to a fluorescent agent accumulated in the lesion or due to the residue. There was a drawback that could not be done.

(Object of invention)
The present invention has been made in view of the above, to provide a fluorescence endoscope KagamiSo location capable of identifying a fluorescent image part and the fluorescent image portion of the residue of a lesion in the case of a body cavity and fluorescence imaging With the goal.

The fluorescence endoscope apparatus according to one aspect of the present invention receives excitation light irradiation means for irradiating a body cavity of a living body with excitation light, fluorescence reception means for receiving fluorescence generated from the body cavity by the excitation light, and light reception Fluorescence image generation means for generating a fluorescence image of the body cavity from fluorescence information, spectrum generation means for generating a fluorescence signal spectrum of the fluorescence , and residue detection means for detecting a residue in the body cavity based on the fluorescence signal spectrum And a residue image processing means for changing a display form of the fluorescence image of the residue on the fluorescence image, wherein the residue detection means includes the first wavelength band generated by the spectrum generation means and the first wavelength band. Fluorescent signal spectra of first to third wavelength bands of three different fluorescences having a second wavelength band shorter than this wavelength and a third wavelength band longer than this wavelength on both sides of one wavelength band. The first to third thresholds are set for each of the fluorescence signal spectra in the first to third wavelength bands, and only the fluorescence signal spectrum in the first wavelength band is larger than the first threshold, and the second and third thresholds are set. When the third fluorescence signal spectrum is not larger than the second and third threshold values, respectively, it is determined that the fluorescence is a lesion part fluorescence.

According to the present invention, it is possible to distinguish a fluorescent image portion of a lesion from a fluorescent image portion due to a residue on a fluorescent image.

  Embodiments of the present invention will be described below with reference to the drawings.

1 to 5 relate to the first embodiment of the present invention, FIG. 1 shows the configuration of the fluorescence endoscope apparatus according to the first embodiment of the present invention, and FIG. 2 is obtained when the lesioned part is irradiated with excitation light. 3 shows the configuration of the image processing apparatus, FIG. 4 shows the processing contents of the residue detection method according to this embodiment, and FIG. 5 shows the processing contents for identifying the residue from the fluorescence spectrum measurement results. Show.
As shown in FIG. 1, a fluorescence endoscope apparatus 1 according to a first embodiment of the present invention includes an optical endoscope 2 inserted into a body cavity 7 and a light guide that transmits illumination light of the endoscope 2. 11 captures a normal image and a fluorescence image with white light (light in the visible region) from the light source device 3 that supplies excitation light and illumination light to the light source 11 and the optical image received and acquired by the endoscope 2. The image processing device 4 includes an image processing device 5, an image processing device 5 that performs image processing on an image signal captured by the image capturing device 4, and a monitor 6 that displays an image processed by the image processing device 5.

The endoscope 2 has an insertion portion 8 that is inserted into the body cavity 7, and a light guide 11 that transmits illumination light is inserted into the insertion portion 8, and the rear end of the light guide 11 is a light source. Connected to device 3.
The light source device 3 includes a lamp 12 that generates white light, for example, as a light source that generates illumination light. The illumination light generated by the lamp 12 is condensed by a condenser lens 13 and rotated by a motor 14. The light guide 11 passes alternately through a white light transmission filter (abbreviated as a white light filter) 16 and an excitation light transmission filter (hereinafter abbreviated as an excitation light filter) 17 that transmit white light attached to the driven rotating plate 15. Is incident on the incident end face at the rear end.
The light incident on the incident end surface of the light guide 11 is transmitted to the distal end surface, spreads from the distal end surface via the illumination lens 18 attached to the illumination window, and is directed to the subject side such as a lesion in the body cavity 7. Irradiated. That is, the lamp 12 and the excitation light filter 17 constitute excitation light irradiation means.

An observation window is provided at the distal end of the insertion portion 8 adjacent to the illumination window. An objective lens 19 is attached to the observation window, and an optical image of the subject is formed at the image formation position. The front end surface of the image guide 20 is disposed at this image formation position. An optical image formed on the front end surface of the image guide 20 is transmitted to the end surface on the hand side, and is captured by the imaging device 4 attached to the end surface. Imaged.
That is, the imaging lens 21 is disposed so as to face the rear end surface of the image guide 20, and the dichroic mirror 22 and the rotating plate 24 rotated by the motor 23 are disposed on the optical axis thereof. Here, the dichroic mirror 22 divides light incident on the observation window of the insertion portion 8 from the body cavity 7 into normal light and fluorescence. The rotary plate 24 is provided with fluorescent filters 25a, 25b, and 25c set so as to transmit a plurality of different wavelengths of fluorescence.
The light emitted from the rear end face of the image guide 20 is collected by the imaging lens 21, and the light reflected by the dichroic mirror 22 at that time is used as a solid-state imaging device for normal observation arranged on the reflected optical axis. The charge coupled device (abbreviated as CCD) 26 forms an image on the imaging surface (light receiving surface), and a normal image is captured by the CCD 26.

On the other hand, the light transmitted through the dichroic mirror 22 passes through the fluorescent filters 25a, 25b, and 25c that are sequentially arranged on the optical axis and passes through the CCD 27 for fluorescence observation that is arranged at the image forming position on the optical axis of the imaging lens 21. An image is formed on the imaging surface. That is, the dichroic mirror 22 and the CCD 27 constitute a fluorescence light receiving means.
The signals photoelectrically converted by both the CCD 26 and the CCD 27 are input to the image processing device 5, and after image processing, an image picked up by the CCD 26 and the CCD 27 is displayed on the monitor 6.
The fluorescent filters 25a, 25b, and 25c attached to the rotary plate 24 have a fluorescence wavelength and a residue that are inherently (or characteristically) generated by a fluorescent agent that is administered to the affected area. ) It is set according to the wavelength of the generated fluorescence.
More specifically, the fluorescent drug administered to the affected area exhibits a unique spectral characteristic that generates fluorescence having a peak at the wavelength λa as shown in FIG.

In this example, the fluorescence generated by the fluorescent agent is observed by administering a fluorescent agent having the characteristic of accumulating in the affected part (or affected part) mainly in the affected part. However, the present invention can also be applied to autofluorescence that occurs even when the lesion site itself does not administer a fluorescent drug. For this reason, in the present specification and claims, including these cases, even when the fluorescence due to the fluorescent agent accumulated in the lesion is to be expressed, the simplified expression is simply used as the fluorescence of the lesion.
In contrast to FIG. 2A, the residue has a unique spectral characteristic that generates fluorescence in a relatively broad wavelength band spanning from a wavelength of 700 nm to a longer wavelength λ2, as shown in FIG. 2B. Show.
That is, in the case of a lesion, fluorescence is generated only in the vicinity of a relatively narrow wavelength λa, whereas in the case of a residue, in addition to this wavelength λa, a shorter wavelength λb and a longer wavelength Wavelength λc.

For this reason, in this embodiment, as the transmission wavelengths of the fluorescent filters 25a, 25b, and 25c, as shown in FIG. 2C, a bandpass in which the wavelength λa and the wavelengths λb and λc on both sides thereof are set as the center wavelengths of the transmission band. A fluorescence spectrum is generated with filter characteristics (indicated by dotted lines). That is, a spectrum generating unit is configured by the plurality of fluorescent filters 25a, 25b, and 25c.
In this case, the filter characteristic is set to a wavelength band of the generated fluorescence, that is, light having a wavelength of near infrared or longer. Then, according to the spectrum measurement result obtained by measuring in this way, when the detection is performed only in the case of the fluorescent filter 25a having the wavelength λa, the fluorescence of the lesioned part and the case of the fluorescent filter 25a having the wavelength λa are detected. In addition, when the fluorescence filters 25b and 25c having the wavelengths λb and λc on both sides are detected, they can be distinguished from the residual fluorescence.

FIG. 3 shows a configuration for performing image processing in the image processing apparatus 5.
The CCD 26 is driven by application of a CCD drive signal from the CCD drive circuit 31a, and an imaging signal corresponding to a white image photoelectrically converted by the CCD 26 is input to the normal image generation circuit 32a. The image pickup signal input to the normal image generation circuit 32 a is converted into a video signal and then input to the mixing circuit 33. The mixing circuit 33 mixes the video signal corresponding to the white image (normal image) captured by the CCD 26 and the video signal corresponding to the fluorescent image captured by the CCD 27 and outputs the mixed signal to the monitor 6. Displays both images.
Further, the CCD 27 is driven by applying a CCD drive signal from the CCD drive circuit 31b, and a fluorescent imaging signal corresponding to a fluorescent image photoelectrically converted by the CCD 27 is a CDS circuit constituting the fluorescent image generation circuit 32b. 34.

After the signal component is extracted by the CDS circuit 34, it is converted into a digital signal by the A / D converter 35 and then stored in the memory 36.
The fluorescence signal data stored in the memory 36 is read out by the CPU 37 as residue detection means for performing processing for identifying whether each part in the fluorescence signal data is a lesioned part or a residue. Then, the residue determination unit (spectrum comparison unit) 38a in the CPU 37 compares it with a threshold value stored in advance in, for example, the ROM 38b, and stores the determination result in, for example, the memory unit 38c.
In the memory 36, the fluorescence signal data of each frame imaged through the fluorescence filters 25a, 25b, and 25c of FIG.

As shown in FIG. 2 (C), the residue determination unit 38a compares the fluorescence signal data captured by the three fluorescence filters 25a, 25b, and 25c with the threshold value stored in advance in the ROM 38b as measurement data. Based on the comparison result, identification information (for example, a flag code) indicating whether the signal is fluorescence signal data of a lesion or fluorescence signal data of residue is stored in the memory unit 38c.
The memory unit 38c stores identification information at the same address as the memory 36, for example. When the fluorescence signal data stored in the memory 36 is read and displayed on the monitor 6, the read address applied to the memory 36 is also applied to the memory unit 38 c so that the corresponding identification information is synchronized. And read.
For this reason, the fluorescence image by the residue displayed on the monitor 6 is displayed by the CPU 37 in a display form different from the fluorescence image of the lesioned part based on the identification information corresponding to the position and size of the residue. Thus, the CPU 37 has a function as residue position detecting means for detecting the position and size of the residue.

The determination by the residue determination unit 38a can be performed for each pixel. However, an identification code may not be attached to a fluorescent image of a residue having a size that is sufficiently small visually. good. Even in the case of a small dot size, if it is displayed in a different display form from the fluorescent image of the lesion, the display form may be disturbed, so the pixel size is also included in the determination condition (this pixel size is It may be possible to select and set on the user side).
The ROM 38b is formed by, for example, an EEPROM or a flash memory as an electrically rewritable nonvolatile memory. Then, in order to determine the residue, a portion that is known (determined) as a residue is imaged in advance, and the fluorescence signal data in that case is stored in the memory 36, and an instruction operation (not shown) is performed. The CPU 37 is controlled so that the fluorescence signal data can be stored in the ROM 38b (as shown by the dotted line in FIG. 3), or the value of the fluorescence signal data can be corrected and set as a threshold value as necessary. ing.

The fluorescent signal data imaged through the fluorescent filter 25a in the memory 36 is converted into an analog video signal through a D / A converter 39, input to the mixing circuit 33, mixed with the video signal on the CCD 26 side, and then monitored. Is output.
In this case, for example, an analog switch 40a as a residue image processing means is provided in the middle of input from the D / A converter 39 to the mixing circuit 33. An oscillator 40b is provided between the analog switch 40a and the memory unit 38c. With this configuration, the oscillation of the oscillator 40b is controlled based on the determination result information stored in the memory unit 38c, and the analog switch 40a is turned on / off.
That is, as will be described later, when it is determined that the fluorescence is from the lesioned part, the analog switch 40a remains ON, but the identification signal determined that the possibility of residue is high is sent to the memory unit 38c. If stored, the analog switch 40a is turned ON / OFF by the oscillation output of the oscillator 40b. And the fluorescence image part determined that the possibility of a residue is high blinks and is displayed.

Next, the operation according to this embodiment will be described below. As shown in FIG. 1, the proximal end of the light guide 11 of the endoscope 2 is connected to the light source device 3, and the rear end of the image guide 20 is connected to the imaging device 4.
Then, the power source of the light source device 3 and the like is turned on, and the insertion portion of the endoscope 2 is inserted into the body cavity 7. Then, as shown in step S1 of FIG. 4, illumination light from the lamp 12 of the light source device 3 passes through the light guide 11 and is irradiated from the distal end surface thereof through the illumination lens 18 to the living tissue side in the body cavity 7.
In this case, since the white light filter 16 and the excitation light filter 17 attached to the rotating plate 15 rotated by the motor 14 are alternately arranged on the illumination light path of the lamp 12, white light (normally) Light) and excitation light are irradiated alternately.
Part of the white light and excitation light irradiated to the living tissue becomes reflected light, and is imaged on the tip surface of the image guide 20 by the objective lens 19. Further, the fluorescence generated by the excitation light is also imaged on the tip surface of the image guide 20 by the objective lens 19. Then, the light is emitted from the rear end surface of the image guide 20 to the imaging device 4 side.

Then, as shown in step S <b> 2 of FIG. 4, the image is picked up (received) by the normal observation CCD 26 and the fluorescence observation CCD 27.
That is, the light emitted from the rear end surface of the image guide 20 is collected by the imaging lens 21. At that time, in the case of white light, the dichroic mirror 22 reflects the wavelength component in the substantially visible region excluding the fluorescent component on the long wavelength side of about 700 nm or more in FIG. 2, and is usually disposed on the reflected optical axis. An image is formed on the imaging surface (light receiving surface) of the observation CCD 26, and a normal image (white image) is captured by the CCD 26.
On the other hand, when the excitation light passing through the excitation light filter 17 is irradiated, the excitation light component on the short wavelength side is cut by the dichroic mirror 22 and only the fluorescence component on the longer wavelength side than about 700 nm is cut by this dichroic. The image is imaged by the CCD 27 for fluorescence observation through the mirror 22 and sequentially through the fluorescence filters 25a, 25b, and 25c arranged on the optical axis.

Signals picked up by the CCDs 26 and 27 are sent to the image processing device 5, and video signals corresponding to the normal image and the fluorescent image are generated as shown in step S3 of FIG.
In the display example on the monitor 6 in FIG. 1, the normal image captured by the CCD 26 is reduced and displayed.
On the other hand, the fluorescence image captured by the CCD 27 is subjected to a fluorescence signal spectrum measurement process as shown in step S4. Processing for determining (identifying) whether the fluorescent image is a residue is performed.

And by this determination process, as shown in step S6, the detection process of the presence or absence of a residue is repeatedly performed with respect to the signal data of each frame displayed on the monitor 6. FIG.
In other words, the residue determination unit 38a in FIG. 3 performs a determination process of whether the image is a fluorescent image of a lesioned part or a fluorescent image of a residue. In this determination process, the fluorescence signal data stored in the memory 36 is sequentially read out and compared with a threshold value for each pixel. Then, the identification information corresponding to the determination result is stored in the memory unit 38c. That is, identification information corresponding to the position of each pixel for which the determination process has been performed is generated as shown in step S7 of FIG.
Then, based on the result of the determination process, when displaying the fluorescent image of the lesioned part and the fluorescent image of the residue as shown in step S8, the residual fluorescent image is displayed differently from the fluorescent image of the lesioned part. The form is displayed on the monitor 6 by blinking, for example.

In this way, by displaying the residual fluorescence image on the monitor 6 in a display form different from that of the lesioned portion, the residue fluorescence image is mixed with the fluorescence image of the lesioned portion and displayed. Even in such a case, the user can easily visually distinguish the fluorescent image due to the residue from other fluorescent images (in this embodiment, the fluorescent image of the lesioned part), and thus the diagnosis can be performed efficiently. It can be carried out.
Next, the processing in steps S5 and S6 in FIG. 4, that is, the contents of the determination processing by the residue determination unit 38a in FIG. 3 will be described in more detail with reference to FIG.
As described in the configuration of the CPU 37 in FIG. 3, the memory 36 stores fluorescence signal data sequentially captured with different spectra (wavelengths) by the fluorescence filters 25a, 25b, and 25c.

And the residue determination part 38a compares with the threshold value Ao stored in ROM38b with respect to the signal data imaged through the fluorescence filter 25a, and stored in ROM38b with respect to the signal data imaged through the fluorescence filter 25b. Compared with the threshold value Bo, the signal data imaged through the fluorescent filter 25c is compared with the threshold value Co stored in the ROM 38b.
In the following description, as shown in FIG. 2C, signal data captured through the fluorescent filters 25a, 25b, and 25c are respectively A, B, and C.
That is, the residue determination unit 38a of the CPU 37 uses the threshold values Ao, Bo, Co for the fluorescence signal data A, B, C captured as shown in steps S11, S12, S13 of FIG. Judgment is made as to whether or not.

In step S11, when the fluorescence signal data A is greater than the threshold value Ao, as shown in steps S12 and S13, the residue determination unit 38a determines whether the fluorescence signal data B is greater than the threshold value Bo and whether the fluorescence signal data C is greater than the threshold value. It is determined whether or not it is larger than Co. On the contrary, in step S11, when the fluorescence signal data A larger than the threshold value Ao is not detected, it is determined that there is almost no fluorescence of the lesioned part and the residue, and this process is ended.
If the signal data B and C do not exceed the threshold values Bo and Co in the determination processing in steps S12 and S13, the process proceeds to step S14, and the residue determination unit 38a determines that the signal data A in this case is fluorescence of residue. Instead, it is determined that the fluorescence is in the affected area, and this process is terminated.
On the other hand, if the signal data B and C exceed the threshold values Bo and Co in the determination processes in steps S12 and S13, the process proceeds to the determination processes in steps S15 and S16 on the assumption that fluorescence that may be a residue is detected. .

In step S15, the residue determination unit 38a has a high possibility of residue depending on the value near the wavelength λb and the value near the wavelength λa from the envelope of the residue fluorescence signal spectrum. A comparison determination is made as to whether or not it is between two threshold values Kba and Hba for determining the range. The threshold value Kba is a lower limit side threshold value, and Hba is an upper limit side threshold value.
Similarly, in step S16, the residue determination unit 38a determines that the signal data ratio C / A is a value near the wavelength λc and a value near the wavelength λa from the envelope of the fluorescence signal spectrum of the residue. A comparison determination is made as to whether or not the difference is between two threshold values Kca and Hca for determining a range where the possibility of the residue is high. Note that the threshold value Kca is a lower limit side threshold value, and Hca is an upper limit side threshold value.
When the determination process of steps S15 and S16 satisfies the condition of Kba <B / A <Hba, or when the condition of Kca <C / A <Hca is satisfied, the process proceeds to step S17, and the residue determination unit 38a In the case, it is determined that the possibility of residue is high. Then, as described with reference to FIG. 3, the residue determination unit 38a writes the identification information of the determination result in the memory unit 38c. This identification information sets, for example, a flag indicating that the possibility of residue is high.

In the next step S18, a residue fluorescence display process is performed. Specifically, when the signal data stored in the memory 36 of FIG. 3 is read and displayed on the monitor 6, information having a high possibility of residue is displayed using the determination information written in the memory unit 38c. At the timing, it blinks with or without a flag (code).
For example, as shown in the display screen example of the monitor 6 in FIG. 1, when a normal image is displayed in the normal image display area 6a and a fluorescent image is displayed in the fluorescent image display area 6b, the fluorescent image of the lesion in the fluorescent image is displayed. While Ia is displayed without blinking, the portion of the fluorescent image Ib that is determined to have a high possibility of residue is displayed blinking.
Accordingly, when the fluorescent image portion of the residue is displayed, the display portion blinks and is displayed in a display form different from the fluorescent image of the lesioned portion. By changing the display form in this way, the user can easily know a fluorescent portion having a high possibility of a residue from the obtained fluorescent image.

On the other hand, if it is determined in steps S15 and S16 that the condition of Kba <B / A <Hba is not satisfied, and if the condition of Kca <C / A <Hca is not satisfied, the process proceeds to step S19, and the residual fluorescence It is determined that there is a low possibility of this process, and this process ends.
In the above description, the determination result of step S19 is not reflected on display, but the determination result of step S19 may also be reflected on display. For example, in the case of step S17, since the possibility of a residue is high, for example, the blinking frequency is displayed with a high frequency, and for the determination result of step S19, the blinking frequency is displayed with a low frequency. Anyway.
Also, instead of processing steps S15 and S16 in FIG. 5A in parallel, the determination process in step S15 is performed as shown in FIG. 5B, and the condition of Kba <B / A <Hba is satisfied. Further, the determination process in step S16 is performed, and if the condition of Kca <C / A <Hca is satisfied, the process proceeds to step S17, and the signal data in this case is determined to have a high possibility of residual fluorescence. Also good.

In this case, the result determined in step S17 is more reliable. That is, the signal data captured through the fluorescent filter 25a and stored in the memory 36 has a very high possibility of residual fluorescence.
As described above, according to the present embodiment, even when actually detected as a fluorescence signal, the case of the residue can be effectively identified from the case of the lesion part from the distribution characteristics of the spectrum, and the display form is different from that of the lesion part. Therefore, the surgeon can easily grasp the possibility of the residue and can make a diagnosis efficiently.
Next, a first modification of the present embodiment will be described with reference to FIG. In the first embodiment, a plurality of fluorescent filters 25a, 25b, and 25c are employed to identify (determine) the fluorescent image of the residue mixed in the fluorescent imaging of the lesioned part.

In the case where the fluorescence spectrum of the residue changes according to the examination site in the body, it is expected that the transmission wavelength of the fluorescence filter can be more reliably identified in response to the change.
For this reason, as one method, the number of fluorescent filters 25a, 25b, and 25c shown in FIG. 1 may be increased, or the rotating plate 24 may be replaced to adopt another fluorescent filter.
As another method, the spectroscopic prism 41 may be employed as in the configuration of the first modification shown in FIG.
That is, as shown in FIG. 6, a spectral prism 41 rotated by a motor 42 is disposed on the optical axis of the light transmitted through the dichroic mirror 22, and the light (specifically, the light split by the spectral prism 41 (specifically, The CCD 27 is arranged to receive (fluorescence).

The spectral prism 41 is reciprocally rotated by a motor 42 within a predetermined angle range (for example, + θ and −θ from a reference angle state). By rotating the spectroscopic prism 41, the fluorescence dispersed by the spectroscopic prism 41 is continuously within a predetermined wavelength band from the wavelength of the reference angle that is not rotated to the long wavelength side and the short wavelength side. So that the CCD 27 can receive (image).
According to this modification, for example, the fluorescence spectrum due to the residue is continuously received (imaged) even when the wavelength band is relatively wide and continuously distributed as shown in FIG. 2B, for example. ) Can be changed, so it can be effectively handled. Further, light may be received at a plurality of substantially discrete wavelengths as follows.
For example, the motor 42 may be configured by a stepping motor, and the rotation angle of the motor 42 may be variably controlled in a step shape by the motor drive circuit 44 via the operation unit 43. That is, by setting the control instruction from the operation unit 43, the fluorescent light having a wavelength that is desired to be received by the CCD 27 is emitted to the CCD 27 side, and the fluorescent light having a wavelength that is not desired to be received by the CCD 27 is The rotation of the motor 42 may be controlled via the motor drive circuit 44 so that the time for which the light is emitted is shortened.

Further, in this case, the fluorescence wavelength substantially received by the CCD 27 can be selected by a selection operation from the operation unit 43, and the fluorescence spectrum of the residue changes depending on the examination site. Can respond. Further, it is possible to cope with a case in which a fluorescent agent (fluorescent dye agent) that generates fluorescence to be administered to a lesioned part is changed.
In addition, using this modification, the fluorescence spectrum is measured for a previously known residue, and the fluorescence spectrum is measured for a portion to which a fluorescent agent has been administered without any residue. The fluorescence spectrum used in the case of performing the process of discriminating between the fluorescence of the lesioned part and the fluorescence of the residue in the actual endoscopy based on the obtained fluorescence spectrum may be determined.
In addition, according to this modification, the fluorescence spectrum of a known residue and a fluorescent agent is measured in advance to obtain unique fluorescence spectrum data that increases in intensity. The filter transmission wavelengths of the fluorescent filters 25a, 25b, and 25c shown in FIG. 1 may be set.

Further, for example, an acousto-optic tunable filter 51 as a variable filter may be employed as in the configuration of the second modification shown in FIG.
That is, as shown in FIG. 7, an acousto-optic tunable filter (abbreviated as AOTF) 51 made of tellurium dioxide or the like is arranged on the optical axis of the light transmitted through the dichroic mirror 22 and is diffracted by the AOTF 51. A CCD 27 is arranged in a direction to receive primary fluorescence.
This AOTF 51 is configured to apply a variable frequency RF signal from a variable RF oscillator 54 to a tellurium dioxide crystal 52 and an acoustic transducer 53 attached to one end face thereof. Note that the tellurium dioxide crystal 52 is fixed to a housing (not shown) on the end surface opposite to the end surface to which the acoustic transducer (ultrasonic transducer) 53 is attached via an absorber 55 that absorbs acoustic vibration. .

Then, by performing an instruction operation for setting the oscillation frequency of the variable RF oscillator 54 from the operation unit 56, the variable RF oscillator 54 applies an RF signal of the instructed oscillation frequency to the acoustic transducer 53, and the tellurium dioxide crystal 52 is The crystal lattice is vibrated at the frequency of the RF signal to expand and contract the crystal lattice (change the refractive index).
For this reason, when fluorescence is incident on the tellurium dioxide crystal 52, it functions as a transmission grating (diffraction grating) or an optical deflector by Bragg diffraction. In this case, unlike a normal grating, the AOTF 51 has a function of diffracting only one specific wavelength, and can realize a very narrow band filter transmission characteristic.
According to this modification, it is possible to obtain fluorescence signal data having a passband with a desired wavelength with ideal filter characteristics.

For this reason, as in the case of the first modified example, when the fluorescence spectrum generated by the residue of the site to be examined in the body cavity changes or when the fluorescence spectrum changes depending on the fluorescent agent used. In such a case, the fluorescent image can be efficiently identified between the lesion and the residue.
Also in this modification example, as described in the first modification example, the spectrum measurement of the fluorescence generated by the residue and the fluorescent agent is performed in advance, and it is used for the setting of the fluorescence spectrum used when identifying both from the measurement result. May be. In this case, according to this modification, it is possible to easily select and set the fluorescence spectrum (specific to the residue and the fluorescent agent) that is effective for identifying the two by the selection setting of the oscillation frequency, and a plurality of fluorescence Since it can be changed discretely to set an arbitrary fluorescence spectrum within the spectrum, it can be performed in a short time.
In addition, the present modification has an advantage that a mechanical movable part that is macroscopically movable is not required than the first modification.

Next, Embodiment 2 of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the component same as Example 1, and the description is abbreviate | omitted. FIG. 8 shows the configuration of the fluorescence endoscope apparatus 1B according to the second embodiment of the present invention.
A fluorescent endoscope apparatus 1B shown in FIG. 8 is an electronic endoscope 2B that is inserted into a body cavity, and a light source device that supplies excitation light and illumination light for normal observation to a light guide 11 of the electronic endoscope 2B. 3B, an image processing device 5B that performs image processing on an image signal captured by the electronic endoscope 2B, and a monitor 6 that displays an image processed by the image processing device 5B. The electronic endoscope 2B has an elongated insertion portion 8 to be inserted into a body cavity, and a light guide 11 is inserted into the insertion portion 8.
The rear end of the light guide 11 is detachably connected to the light source device 3B. In the light source device 3B, three excitation light filters 17a, 17b, and 17c are attached instead of the excitation light filter 17 that is one on the rotary plate 15 in the light source device 3 of the first embodiment.

FIG. 9 shows the spectral intensity distribution and the like of the excitation light that has passed through the excitation light filters 17a, 17b, and 17c. The excitation light filter 17a generates excitation light E1 having a wavelength λA (= λa) that generates fluorescence having the highest intensity in the fluorescence spectrum distribution of the lesion. The excitation light filters 17b and 17c transmit the excitation light E2 having a wavelength λB shorter than the wavelength λA and the excitation light E3 having a wavelength λC longer than the wavelength λA (in FIG. 9, the corresponding excitation light filters 17a, 17c, 17b and 17c are also shown in parentheses).
The case where the excitation light filter 17a is set to generate excitation light E1 in the case of generating fluorescence with the highest intensity in the fluorescence spectrum distribution of the residue will be described later with reference to FIG.
Since the rotating plate 15 is rotationally driven by the motor 14, white light and excitation light filters 17a, 17b, and 17c are sequentially passed through the incident end surface of the rear end of the light guide 11, and excitation light E1, E2, and E3 are passed through. Sequentially incident.

The light incident on the incident end surface of the light guide 11 is transmitted to the distal end surface, spreads from the distal end surface via the illumination lens 18 attached to the illumination window, and is directed to the subject side such as a lesion in the body cavity 7. Irradiated.
Two observation windows are provided adjacent to the illumination window at the distal end of the insertion portion 8, and objective lenses 19 a and 19 b are attached to the two observation windows, and the normal observation CCD 26 is provided at each imaging position. And a fluorescence observation CCD 27 are arranged.
A fluorescence filter 61 is disposed in front of the fluorescence observation CCD 27. The fluorescent filter 61 has a band-pass filter characteristic that transmits fluorescence as shown in FIG. Further, in FIG. 8, signal data obtained by imaging with the CCD 27 by the excitation light sequentially passing through the excitation light filters 17a, 17b, and 17c are indicated by F1, F2, and F3.

The image signals picked up by the CCDs 26 and 27 are input to the image processing device 5B, subjected to image processing, and then the generated image signal is output to the monitor 6. A normal image and a fluorescent image are displayed on the display surface of the monitor 6. Is done.
The internal configuration of the image processing device 5B is substantially the same as that of the image processing device 5 of the first embodiment shown in FIG. 3, and the operation will be described using the same reference numerals. However, the threshold value stored in the ROM 38b in the CPU 37 is different from that in the first embodiment, and the residue determination process similar to that in the first embodiment is performed using the threshold value stored in the ROM 38b (see FIG. This will be described later with reference to FIG.
Next, the operation of this embodiment will be described. The overall operation in the present embodiment is the operation according to the flowchart of FIG. 4 in the first embodiment.
However, in the first embodiment, a plurality of fluorescent signal data is acquired using a plurality of fluorescent filters 25a, 25b, and 25c having different transmission bands, and a fluorescence signal of a lesioned part or a residue is obtained by the CPU 37 for the plurality of fluorescent signal data. However, in this embodiment, a plurality of fluorescence signal data are acquired by using the excitation lights E1, E2, and E3 that are sequentially passed through the plurality of excitation light filters 17a, 17b, and 17c. The CPU 37 determines whether the signal data is a fluorescent signal of a lesion or residue.

For this reason, as the measurement process of the fluorescence signal spectrum in step S4 of FIG. 4, more specifically, the fluorescence signal is measured by changing the irradiation spectrum of the excitation light. Then, the fluorescence signal is measured by changing the irradiation spectrum of the excitation light in this way, and the processing after step S5 shown in FIG. 4 is performed on the signal data. The process after step S5 is shown in more detail in FIG.
Hereinafter, the residue determination process illustrated in FIG. 10 will be described. The ROM 38b in the image processing apparatus 5B in the present embodiment stores F1 ′, F2 ′, and F3 ′ as thresholds corresponding to the thresholds Ao, Bo, and Co in the first embodiment. Further, N21, M21, N31, and M31 are stored as threshold values corresponding to the threshold values Kba, Hba, Kca, and Hca in the first embodiment.
That is, when the residue determination process starts, the residue determination unit 38a of the CPU 37 sets the value of the fluorescence signal data F1, F2, and F3 captured as shown in steps S21, S22, and S23 of FIG. It is determined whether F1 ', F2', and F3 'are exceeded.

In step S21, when the fluorescence signal data F1 is larger than the threshold value F1 ′, as shown in steps S22 and S23, the residue determination unit 38a determines whether the fluorescence signal data F2 is larger than the threshold value F2 ′ and the fluorescence signal data F3. Is determined to be greater than the threshold value F3 ′. On the contrary, in step S21, when the fluorescence signal data A larger than the threshold value F1 ′ is not detected, it is determined that there is almost no fluorescence of the lesioned part and the residue, and this process is ended.
If the signal data F2 and F3 do not exceed the threshold values F2 ′ and F3 ′ in the determination processes in steps S22 and S23, the process proceeds to step S24, and the residue determination unit 38a determines that the signal data F1 in this case is a residue. This processing is terminated by determining that it is fluorescence of the lesioned part instead of the fluorescence of.
On the other hand, in the determination process of steps S22 and S23, if the signal data F2 and F3 exceed the threshold values F2 ′ and F3 ′, the determination process of steps S25 and S26 is performed on the assumption that the fluorescence that may be a residue is detected. Proceed to

In step S25, the residue determination unit 38a performs a comparison determination as to whether or not the ratio F2 / F1 of the signal data is between two threshold values N21 and M21 for determining a range where the possibility of the residue is high. The threshold value N21 is a lower limit side threshold value, and M21 is an upper limit side threshold value.
Similarly, in step S26, the residue determination unit 38a compares the signal data ratio F3 / F1 between two threshold values N31 and M31 for determining a range in which the possibility of residue is high. Make a decision. The threshold value N31 is a lower threshold value, and M31 is an upper threshold value.
Then, when the condition of N21 <F2 / F1 <M21 is satisfied by the determination process of steps S25 and S26, or when the condition of N31 <F3 / F1 <M31 is satisfied, the process proceeds to step S27, and the residue determination unit 38a In the case, it is determined that the possibility of residue is high. As described with reference to FIG. 3 of the first embodiment, the residue determination unit 38a writes the identification information of the determination result in the memory unit 38c. This identification information sets, for example, a flag indicating that the possibility of residue is high.

Then, in the next step S28, a residue fluorescence display process is performed. Specifically, when the fluorescence signal data stored in the memory 36 of FIG. 3 is read and displayed on the monitor 6, there is a possibility of residue using the identification information (determination result information) written in the memory unit 38c. At the timing when high information is displayed, the display is controlled to blink according to the presence or absence of a flag (code), and the display form is changed.
Accordingly, when the fluorescent image portion of the residue is displayed, the display portion is displayed blinking unlike the fluorescent image of the lesioned portion. By changing the display form in this way, the user can easily know a fluorescent image portion having a high possibility of residue from the obtained fluorescent image.
On the other hand, if the condition of N21 <F2 / F1 <M21 is not satisfied by the determination process of steps S25 and S26, and if the condition of N31 <F3 / F1 <M31 is not satisfied, the process proceeds to step S29, where the residual fluorescence It is determined that the possibility is low, and this process is terminated.

In the above description, the determination result in step S29 is not reflected at the time of display. However, as described in the first embodiment, the determination result at step S29 may be reflected at the time of display.
Further, instead of processing steps S25 and S26 of FIG. 10 in parallel, the determination process of step S25 is performed in the same manner as shown in FIG. 5B, and the condition of N21 <F2 / F1 <M21 is satisfied. If the condition of N31 <F3 / F1 <M31 is further satisfied, the process proceeds to step S27. In this case, the signal data is determined to have a high possibility of residual fluorescence. May be.
In this case, the result determined in step S27 is more reliable.
As described above, according to the present embodiment, even when a fluorescence signal is actually detected, a residue can be effectively identified from the case of a lesion from the distribution characteristics of the spectrum, and the display form is different from that of the lesion. Therefore, the surgeon can easily grasp the possibility of the residue and can make a diagnosis efficiently.

In this embodiment, the excitation light E1 is set in the vicinity of the wavelength λA (= λa) suitable for the most effective generation of the fluorescence of the lesion. For example, the excitation light E1 generates the residual fluorescence most effectively. It is also possible to set the wavelength to be used and determine the residue by setting one of the other excitation lights E2 and E3 to the excitation light that most effectively generates the fluorescence of the lesion.
The residue determination process in this case is shown in FIG. In this case, only residue is determined. The process shown in FIG. 11 determines that the signal data F2 and F3 do not exceed the threshold values F2 ′ and F3 ′ in steps S22 and S23 in the process shown in FIG. Exit. The other processing contents are the same as the processing contents of FIG.
In the above description, as an example of the residual fluorescence display process, an example in which a fluorescent image that may be a residue is blinked and displayed is displayed. You may make it display with a color.
In this case, for example, by controlling the signal input to one channel of the monitor 6, for example, the R signal channel, with the flag code of the memory unit 38 c, if a residual fluorescent image exists in the fluorescent image, While the fluorescent image is displayed in monochrome, for example, it is displayed in a color obtained by combining green and blue due to the lack of the R color signal.

  Further, as the excitation light irradiation means, a plurality of laser light sources (not shown) may be used instead of the lamp 12 and the excitation light filter 17. Here, each laser light source of the plurality of laser light sources is configured to emit excitation light having different wavelength bands, and is controlled to emit light sequentially. In this way, a plurality of excitation light beams of different wavelength bands are sequentially incident on the incident end face of the light guide 11, transmitted by the light guide 11, and then through the illumination lens 18 on the subject side such as a lesioned part in the body cavity 7. Is irradiated. According to this configuration, it is not necessary to arrange a plurality of excitation light filters 17a, 17b, 17c and the like, and thus the light source device 3B can be reduced in size. It should be noted that, in addition to the laser light source, similar effects can be obtained by using LEDs or the like.

  Fluorescence imaging is performed by irradiating excitation light, and when a fluorescence image is displayed on a monitor, a fluorescence image due to the residue may be displayed. By identifying the fluorescence image due to the residue from the fluorescence signal obtained using the excitation light filter that generates fluorescence and displaying it in a display form different from that due to the lesion, it is possible to easily recognize the fluorescence image due to the residue.

1 is an overall configuration diagram of a fluorescence endoscope apparatus according to a first embodiment of the present invention. The figure which shows the example of a fluorescence spectrum characteristic obtained when excitation light is irradiated to a lesioned part. 1 is a block diagram illustrating a configuration of an image processing apparatus. The flowchart figure which shows the processing content of the residue detection method by a present Example. The flowchart figure which shows the processing content which identifies a residue from a fluorescence spectrum measurement result. The figure which shows the structure of the imaging device vicinity in a 1st modification. The figure which shows the structure of the imaging device vicinity in a 2nd modification. The whole block diagram of the fluorescence endoscope apparatus of Example 2 of the present invention. The figure which shows the spectral intensity distribution etc. of the excitation light irradiated through an excitation light filter. The flowchart figure which shows the processing content which identifies the residue in Example 2. FIG. The flowchart figure which shows the processing content which identifies a residue.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fluorescence endoscope apparatus 2 ... Endoscope 3 ... Light source apparatus 4 ... Imaging device 5 ... Image processing apparatus 6 ... Monitor 7 ... Body cavity 8 ... Insertion part 11 ... Light guide 12 ... Lamp 16 ... White light filter 17 ... Excitation Optical filter 19 ... Objective lens 20 ... Image guide 21 ... Imaging lens 22 ... Dichroic mirror 25a, 26b, 25c ... Fluorescent filter 26, 27 ... CCD
33 ... Mixed circuit 36 ... Memory 37 ... CPU
38a ... residue determination part 38b ... ROM
38c ... Memory section

Claims (9)

  An excitation light irradiation means for irradiating the living body cavity with excitation light;
  Fluorescence receiving means for receiving fluorescence generated from the body cavity by the excitation light;
  Fluorescence image generation means for generating a fluorescence image of the body cavity from the received fluorescence information;
  Spectrum generating means for generating a fluorescence signal spectrum of the fluorescence;
  Residue detection means for detecting residues in the body cavity based on the fluorescence signal spectrum;
  A residue image processing means for changing a display form of the fluorescence image of the residue on the fluorescence image;
  Have
  The residue detecting means includes a first wavelength band generated by the spectrum generating means, a second wavelength band having a shorter wavelength than the first wavelength band, and a third wavelength band having a longer wavelength on both sides of the first wavelength band. The first to third fluorescence signal spectra of the first to third wavelength bands of three different fluorescence having the first and third wavelength bands are input, and the first to third threshold values are set for each of the fluorescence signal spectra of the first to third wavelength bands. When only the fluorescence signal spectrum of the first wavelength band is larger than the first threshold and the second and third fluorescence signal spectra are not larger than the second and third thresholds, respectively, the fluorescence of the lesioned part A fluorescence endoscope apparatus characterized by determining.   The residue detection means further includes
  Each of the fluorescence signal spectra in the first to third wavelength bands is all larger than the first threshold value to the third threshold value, and the ratio of the fluorescence signal spectrum in the second wavelength band to the fluorescence signal spectrum in the first wavelength band is The sixth threshold value on the lower limit side is greater than the fourth threshold value on the lower limit side and smaller than the fifth threshold value on the upper limit side, or the ratio of the fluorescence signal spectrum in the third wavelength band to the fluorescence signal spectrum in the first wavelength band 2. The fluorescence endoscope apparatus according to claim 1, wherein when it is larger and smaller than a seventh threshold value on the upper limit side, it is determined that the possibility of fluorescence of the residue is high.   The residue detection means further includes
  Each of the fluorescence signal spectra in the first to third wavelength bands is all larger than the first threshold value to the third threshold value, and the ratio of the fluorescence signal spectrum in the second wavelength band to the fluorescence signal spectrum in the first wavelength band is The ratio of the fluorescence signal spectrum in the third wavelength band to the fluorescence signal spectrum in the first wavelength band is not lower than the fourth threshold on the lower limit side or smaller than the fifth threshold on the upper limit side. 3. The fluorescence endoscope apparatus according to claim 1, wherein when the threshold value is not greater than 6 or less than the seventh threshold value on the upper limit side, it is determined that the possibility of residual fluorescence is low. .   The threshold value in said residue detection means is set based on the intrinsic fluorescence spectrum of the lesioned part in said body cavity and the intrinsic fluorescence spectrum of the residue, The intrafluorescence according to any one of claims 1 to 3, Endoscopic device.   The fluorescence endoscope according to any one of claims 1 to 3, wherein the residue image processing means displays the fluorescence image of the residue on the image display means separately from other fluorescence images. apparatus.   The fluorescence endoscope apparatus according to claim 1, wherein the spectrum generation unit includes a spectral prism.   The excitation light irradiation means irradiates one band of excitation light into the body cavity,
  The spectrum generating means has a multi-band transmission filter that cuts the excitation light and transmits a plurality of bands of fluorescence,
  The fluorescence endoscope apparatus according to claim 1, wherein the fluorescence signal spectrum is generated based on fluorescence transmitted through the multiband transmission filter.   The fluorescence endoscope apparatus according to claim 7, wherein the multiband transmission filter is a plurality of variable filters.   The fluorescence endoscope apparatus according to claim 7, wherein the multiband transmission filter is a filter that targets light having a wavelength of near infrared or longer.

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