Electronic endoscope device for fluoroscopy

【0001】

[Technical field to which the invention belongs]

The present invention is an electronic endoscope device for fluorescence diagnosis that images the inside of a body cavity based on autofluorescence emitted from a living body and outputs image data used for diagnosing whether the living body is normal or abnormal. ,.

【0002】

[Conventional technology]

It is known that when a living body is irradiated with excitation light of a specific wavelength, fluorescence is emitted from the living body (this fluorescence is called "autofluorescence"). Furthermore, since the intensity of the green light region of autofluorescence is lower in the abnormal part (tumor, cancer) of the living body than in the normal part, the abnormal part may be displayed darker than the normal part when displayed as an image. Are known.

【0003】

Based on this knowledge, Professor Harubumi Kato of Tokyo Medical University was the first in the world to take an autofluorescence image of a living body and create an autofluorescence image to be used for diagnosis of whether the living body is normal or abnormal. An electronic endoscopy device for fluorescent diagnosis to be displayed was invented, and based on this idea, the applicant proceeded with the development, and as a result, an example born was disclosed in Japanese Patent Application Laid-Open No. 9-70384. is there.

【0004】

In the electronic endoscope device for fluorescence diagnosis disclosed in this publication, it is considered that autofluorescence is very weak light, and between the objective optical system and the image sensor at the tip of the electronic endoscope, An image intensifier that amplifies autofluorescence is provided. Therefore, according to this electronic endoscope device for fluorescence diagnosis, an image of autofluorescence amplified by the image intensifier is imaged by the image pickup device, so that a bright autofluorescence image can be obtained.

【0005】

[Problems to be Solved by the Invention]

However, when the image intensifier is incorporated in the tip of the electronic endoscope in this way, the outer diameter of the tip becomes large. Since this tip is a part to be inserted into the body cavity of the patient, if the tip becomes too thick, there is a problem that the patient is burdened. Further, since the image intensifier is relatively expensive, if the image intensifier is incorporated in the tip of the electronic endoscope, there is a problem that the cost of the entire electronic endoscope device for fluorescence diagnosis increases.

【0006】

An object of the present invention is to provide an electronic endoscope device for fluorescence diagnosis, which can obtain an appropriate image for fluorescence diagnosis without using an image intensifier.

【0007】

[Means for solving problems]

The present invention has adopted the following configuration in order to solve the above problems.

【0008】

That is, the invention according to claim 1 is<u style="single">It has an illumination device that switches between illumination light in the visible band and excitation light in the ultraviolet band to irradiate the living body, and also emits illumination light in the visible band.</u>Irradiated<u style="single">Normal observation image of the living body and the above</u>Excitation light<u style="single">Said</u>Caused by irradiating the living body<u style="single">Of the living body</u>Image of autofluorescence<u style="single">Respectively</u>An imaging device that captures images and<u style="single">A luminance region higher than the first threshold is extracted from the normal observation image, a luminance region lower than the second threshold is extracted from the autofluorescent image, and among the regions extracted from the normal observation image, the autofluorescent image is used. The area included in the extracted area is set as a specific area.</u>A detection unit to detect and a display control device that outputs an image signal indicating the specific area.<u style="single">Place and</u>It is an electronic endoscope device for fluorescence diagnosis provided with.

【0009】

When configured in this way, the detector<u style="single">Is special</u>Since the fixed area is extracted and the display control device outputs an image signal indicating the specific area, an image showing the shape and position of the specific area can be displayed on a display device such as a CRT or a liquid crystal display. Therefore, if the brightness range of the specific region extracted by the detection unit is set to the range to which the brightness of the autofluorescence emitted from the abnormal portion of the living body belongs, the abnormal region is displayed as the specific region. Therefore, even if the image intensifier is not provided, an appropriate image for fluorescence diagnosis can be provided to a user (doctor, etc.) of an electronic endoscope device for fluorescence observation, and the user can appropriately perform autofluorescence. Can make a diagnosis based on.

【0010】

Here, the detection unit and the display control device can be configured as, for example, a function by executing a program of a CPU (central processing unit), or can be configured by an LSI, an ASIC, or the like.

【0013】

Also, claims<u style="single">2</u>The described invention is specified by the display control device of claim 1 by outputting an image signal for displaying a fluorescence observation image in which only the specific region is shown in a predetermined color. With this configuration, if there is an abnormal part in the living body as the subject, the abnormal part is displayed in a predetermined color as a specific area in the fluorescence diagnosis image. Therefore, the device user can easily diagnose whether or not the site is abnormal.

【0014】

Also, claims<u style="single">3</u>The described invention is claimed.<u style="single">1</u>The display control device of is only the specific area of the normal observation image.<u style="single">single</u>It is specified by outputting an image signal for displaying a fluorescence observation image which is shown in color and shows a fluorescence observation image other than the specific region in color. The entire fluorescence observation image may be displayed in monochrome, or the area other than a specific area may be displayed in pseudo color. However, if only the specific area is displayed in a predetermined color and the area other than the specific area is displayed in color, the diagnosis becomes easier.

【0015】

Also, claims<u style="single">4</u>The described invention is claimed.<u style="single">3</u>The image pickup device of the above captures a normal observation image of the living body when each illumination light is irradiated, while irradiating the living body with each of red, green, and blue illumination lights in order by the lighting device, and displays the above. The control device synthesizes a color image based on the normal observation image of the living body when each of the illumination lights is irradiated, and generates a specific region image obtained by extracting only the specific region from the self-fluorescent image. This is specified by outputting an image signal for displaying a fluorescence observation image formed by superimposing the specific region image on the color image.

【0016】

Also, claims<u style="single">5</u>The described invention is claimed.<u style="single">4</u>The display control device of the above is specified by outputting an image signal for simultaneously displaying the color image and the fluorescence observation image. With this configuration, the user can compare and observe the two images, so that the normal / abnormal diagnosis of the living body can be easily performed.

【0017】

Also, claims<u style="single">6</u>The described invention is claimed.<u style="single">1</u>The display control device of the above is specified by outputting an image signal for displaying the normal observation image as a moving image.

【0018】

Also, claims<u style="single">7</u>The described invention is claimed.<u style="single">6</u>The display control device is operated by the operator to switch between an image signal for displaying only the normal observation image and an image signal for displaying the normal observation image and the fluorescence diagnosis image at the same time. This is specified by further providing a switch that generates a changeover signal for the purpose.

【0019】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Structure of Electronic Endoscope Device] FIG. 1 is a schematic configuration diagram of an electronic endoscope device for fluorescence observation (hereinafter, simply referred to as electronic endoscope device) 10 according to the present embodiment. In FIG. 1, the electronic endoscope device 10 includes an electronic endoscope 11, a light source device 12 and a video processor 13 connected to the electronic endoscope 11, and a personal computer (PC) 14 connected to the video processor 13. It is composed of a monitor 15 and a monitor 15. Hereinafter, each of these devices will be described individually.

【0020】

Although only the insertion portion 16 is shown in FIG. 1, the electronic endoscope 11 is actually provided with a dial and various operation switches for bending the curved portion provided near the tip of the insertion portion. It is composed of various parts such as the operation unit and the light guide flexible tube connected to the light source device 12. The insertion portion 16 illustrated in FIG. 1 is a part to be inserted into the body cavity of a living body as a subject, and at least two through holes are formed at the tip of the insertion portion 16 along the axial direction. The tip (not shown) made of a hard member is fixed.

【0021】

The objective optical system 18 and the light distribution lens 21 are fitted into the openings on the tip side of the insertion portion 16 of these two through holes, respectively. The objective optical system 18 is an imaging optical system that forms an image of a subject, and a cutoff filter 19 and a solid-state image sensor (CCD) 17 are fixed in order behind the objective optical system 18 (base end side). .. When the subject is irradiated with excitation light (ultraviolet rays) for exciting autofluorescence, the cutoff filter 19 reflects the excitation light on the surface of the subject and blocks the excitation light transmitted through the objective optical system 18. The CCD 17 is arranged at the imaging position of the subject by the objective optical system 18, and is connected to the video processor 13 via the signal line 17a. The image signal obtained by imaging the subject image by the objective optical system 18 by the CCD 17 is input to the video processor 13 via the signal line 17a and processed by the video processor 13.

【0022】

On the other hand, on the proximal end side of the light distribution lens 21, a light guide fiber bundle (hereinafter referred to as "light") is drawn to the insertion portion 16 through a light guide flexible tube (not shown) of the electronic endoscope 11 and an operation portion. There are 20 exit end faces (called "guides"). Since the incident end surface of the light guide 20 is arranged inside the light source device 12, the light guide 20 transmits the illumination light supplied from the light source device 12 to the tip of the insertion portion 16. The illumination light emitted from the emission end surface of the light guide 20 is expanded by the light distribution lens 21 and illuminates the imaging range of the objective optical system 18 and the CCD 17.

【0023】

The light source device 12 is a device that supplies illumination light to the light guide 20, and a white light source 22 is provided inside the light source device 12. The white light source 22 is composed of a lamp that emits white light as illumination light for normal observation and a reflector that converges the white light emitted from the lamp. Since the incident end face of the light guide 20 described above is arranged at a position where the white light converges on the optical axis of the reflector of the white light source 22, the illumination light emitted from the white light source 22 is efficiently used in the light guide 20. Incident in.

【0024】

An RGB rotation filter 23 is arranged in the middle of the optical path of the illumination light between the light guide 20 and the white light source 22. The RGB rotation filter 23 has a fan-shaped planar shape with an equal angle, and has three color filters of R (red), G (green), and B (blue) arranged with a light-shielding portion sandwiched between them. It is rotated at a constant speed by a motor (not shown). Therefore, each color filter incorporated in the RGB rotation filter 23 is repeatedly inserted into the optical path of the illumination light emitted from the white light source 22 in the order of R, G, B. As a result, the illumination lights of R light, G light, and B light are repeatedly incident on the incident end face of the light guide 20, are emitted from the tip of the insertion portion 16 through the light guide 20, and are emitted through the light distribution lens 21. Illuminate the subject. Then, the CCD 17 captures an image (that is, the subject image) of the subject illuminated by each illumination light by the objective optical system 18, and the video processor 13 synthesizes it as a color image. In this way, imaging by the so-called RGB plane sequential method is performed.

【0025】

Further, inside the light source device 12, a light source (UV light source) 24 composed of a lamp that emits ultraviolet rays as excitation light for self-fluorescence and a reflector that converges the excitation light emitted from this lamp 24, this UV light source A first mirror 25 and a second mirror 26 that guide the excitation light emitted from 24 to the incident end face of the light guide 20 are provided. The first mirror 25 is arranged outside the optical path of the excitation light emitted from the UV light source 24 during normal observation, is inserted into the optical path of the excitation light during fluorescence diagnosis, and reflects the excitation light toward the second mirror 26. To do. The second mirror 26 is arranged outside the optical path of the illumination light emitted from the white light source 22 during normal observation, and is inserted into the optical path of the illumination light between the RGB rotation filter 23 and the light guide 20 during fluorescence diagnosis. Therefore, the illumination light from the white light source 22 is blocked, and the excitation light reflected by the first mirror 25 is reflected toward the incident end face of the light guide 20. With the above configuration, illumination light (R light, G light, B light) that has passed through the RGB rotation filter 23 is incident on the incident end face of the light guide 20 during normal observation, and excitation light emitted from the UV light source 24 is emitted during fluorescence diagnosis. It is incident on the incident end face of the light guide 20.

【0026】

Further, the light source device 12 has a light source control unit 27. The light source control unit 27 adjusts the amount of illumination light and excitation light incident on the light guide 20 according to instructions from, for example, the PC 14, and also has a white light source 22, an RGB rotation filter 23, a first mirror 25, and a second mirror. Controls 26 operations. Further, the light source control unit 27 gives the PC 14 a signal (synchronous signal) indicating the timing at which each of the RGB color filters passes through the optical path of the illumination light emitted from the white light source 22.

【0027】

The video processor 13 has a switch SW connected to the signal line 17a. The switch SW is a switch consisting of two output terminals T1 and T2 and an input terminal conductive to a switch piece that can selectively contact each of these output terminals T1 and T2, but in reality, such a configuration is used. It is configured as an electronic circuit equivalent to the switch of. The switch piece of this switch SW contacts the output terminal T1 during normal observation and contacts the output terminal T2 during fluorescence diagnosis. The output terminal T1 of the switch SW is connected to the input terminal of the analog / digital converter (A / D converter) 28.

【0028】

The A / D converter 28 converts the output signal (image signal) of the CCD 17 during normal observation into analog-digital conversion and outputs it to the output terminal. The output terminals of the A / D converter 28 are connected to the input terminals of the R memory 29, the G memory 30, and the B memory 31, respectively.

【0029】

The R memory 29 stores an image signal (referred to as R image signal) output from the CCD 17 when the subject is irradiated with R light. Further, the G memory 30 stores an image signal (referred to as G image signal) output from the CCD 17 when the subject is irradiated with G light. Further, the B memory 31 stores an image signal (referred to as B image signal) output from the CCD 17 when the subject is irradiated with B light.

【0030】

On the other hand, the output terminal T2 of the switch SW is connected to the input terminal of the amplifier 32. This amplifier 32 amplifies the image signal (referred to as F image signal) output from the CCD 17 at the time of fluorescence diagnosis, and outputs the image signal to the output terminal thereof. The output terminal of this amplifier 32 is connected to the input terminal of the A / D converter 33. The A / D converter 33 converts the F image signal amplified by the amplifier 32 into analog and digital, and outputs the signal to its output terminal. The output terminal of this A / D converter 33 is connected to the input terminal of the F memory 34. The F memory 34 stores the F image signal output from the A / D converter 33.

【0031】

The output terminals of the R memory 29, the G memory 30, the B memory 31 and the F memory 34 are connected to the scan converter 36. Each output terminal of this scan converter 36 is connected to PC14. The scan converter 36 reads each RGB image signal stored in the R memory 29, the G memory 30, and the B memory 31 according to the synchronization signal input from the PC 14, synchronizes the signals, and outputs the signals to the PC 14. .. Similarly, the scan converter 36 reads the F image signal from the F memory 34 according to the synchronization signal input from the PC 14, and outputs the F image signal to the PC 14.

【0032】

The video processor 13 has a microcomputer (MIC) 35. This MIC35 is connected to the PC 14 and is also connected to an external switch 36a provided outside the video processor 13. The MIC35 is also connected to each control terminal of the switch SW, the amplifier 32, the R memory 29, the G memory 30, the B memory 31 and the F memory 34. This MIC35 selectively brings the switch piece of the switch SW into contact with either the output terminal T1 or the output terminal T2 according to the control command from the PC14. Further, the MIC35 adjusts the amplification factor of the amplifier 32 according to the control instruction from the PC14. Further, the MIC 35 stores the output signals from the A / D converters 28 and 33 in the corresponding memory among the R memory, the G memory, the B memory, and the F memory according to the synchronization signal input from the PC 14.

【0033】

Further, the video processor 13 has a digital / analog converter (D / A converter) 37 connected to the PC 14. The D / A converter 37 converts the RGB image signal output from the PC 14 into digital / analog and inputs it to the monitor 15. As a result, the monitor 15 displays an image of the subject based on the analog RGB image signal.

【0034】

The PC 14 is a computer that further performs image processing on each image signal output from the video processor 13. As shown in detail in the block of FIG. 2, the PC 14 is connected to a CPU (central processing unit) 38 connected to a light source control unit 27 of the light source device 12 and a MIC 35 of the video processor 13, and to the CPU 38. It is composed of a video capture 39, a memory unit 40, and a VRAM (video RAM) 41.

【0035】

The video capture 39 temporarily stores each RGB image signal or F image signal output from the scan converter 36 of the video processor 13, and inputs the RGB image signal or the F image signal to the memory unit 40 according to an instruction from the CPU 38.

【0036】

The memory unit 40 has a memory M1 (mem_RGB) area for storing each RGB image signal output from the video capture 39 and a memory MF (mem_FL) area for storing the F image signal output from the video capture 39. It is a RAM (Random Access Memory) that is distinguished from the memory M2 (mem_RGB2) area used for the process of creating the image for fluorescence diagnosis, and is used for the process by the CPU 38.

【0037】

The VRAM 41 holds data (RGB image signal) indicating the content to be displayed on the monitor 15 output from the CPU 38, and outputs the held RGB image signal to the D / A converter 37 according to the instruction from the CPU 38. ..

【0038】

The CPU 38 controls the operations of the light source control unit 27, MIC35, video capture 39, memory unit 40, and VRAM41 by executing a control program stored in a ROM (Read Only Memory) (not shown).

【0039】

Hereinafter, an operation example of the electronic endoscope device including each device having the above configuration will be described along with the processing by the CPU 38 of the PC 14.

【0040】

FIG. 3 is a flowchart showing the processing (main routine) by the CPU 38, and FIG. 4 is a flowchart showing the subroutine of the fluorescence diagnosis image generation processing executed in S8 of FIG. The process shown in FIG. 3 is triggered by turning on the main power of the light source device 12, the video processor 13, and the PC 14 respectively.

【0041】

After the start, the CPU 38 first gives a control command to the light source control unit 27 to operate the light source device 12 in the normal observation state (S1). Then, the light source control unit 27 of the light source device 12 makes the first mirror 25 evacuate outside the optical path of the excitation light emitted from the UV light source 24, and the second mirror outside the optical path of the illumination light emitted from the white light source 22. Retract 26 (see broken line in Figure 1). Subsequently, the light source control unit 27 turns on the white light source 22 and the UV light source 24, and rotates the RGB rotation filter 23. Then, the light source control unit 27 gives the synchronization signal of the RGB rotation filter 23 to the CPU 38. The CPU 38 feeds this synchronization signal to the MIC 35 and the scan converter 36 (S2). In addition, the CPU 38 gives a control command to the MIC 35 to bring the switch piece of the switch SW into contact with the output terminal T1 (S3). As a result, the MIC35 brings the switch piece of the switch SW into contact with the output terminal T1.

【0042】

By executing the control from S1 to S3 so far, white illumination light is emitted from the white light source 22, and this white illumination light passes through the RGB rotation filter 23 to generate R light, G light, and B light. It becomes each illumination light of the above, and in turn, it is incident on the light guide 20. Then, the illumination light of each color is transmitted to the tip of the electronic endoscope 11 through the light guide 20, emitted from the exit end surface of the light guide 20, and diffused by the light distribution lens 21 while being diffused by the subject (that is, the inner wall of the body cavity). Illuminate in order.

【0043】

When the subject is sequentially illuminated by each illumination light, the reflected light from the subject forms an image of the subject on the imaging surface of the CCD 17 by the objective optical system 18, and this subject image is captured by the CCD 17. Then, the image signals (R image signal, G image signal, B image signal) based on each illumination light are sequentially output from CCD17. Each image signal is input to the A / D converter 28 via the signal line 17a and the switch SW, analog-to-digital converted by the A / D converter 28, and input to the input terminals of the memories 29, 30 and 31. At this time, the MIC 35 sequentially inputs control signals to the control terminals of the memories 29, 30, and 31 based on the synchronization signal from the CPU 38.

【0044】

When this control signal is input, each memory 29, 30, 31 takes in the image signal output from the A / D converter 28 at that time, and holds the image signal until the next control signal is input. Continue to do. Therefore, the R image signal is stored in the R memory 29, the G image signal is stored in the G memory 30, and the B image signal is stored in the B memory 31. In this way, each of the RGB image signals is stored in the R memory 29, the G memory 30, and the B memory 31 for one screen. Then, the scan converter 36 reads each of the RGB image signals from the memories 29 to 31, synchronizes them, and outputs them to the PC 14. Each RGB image signal transmitted to the PC 14 in this way is stored in the video capture 39 of the PC 14.

【0045】

Then, the CPU 38 sequentially writes the RGB image signals stored in the video capture 39 to the memory M1 of the memory unit 40 (S4). As a result, on the memory M1, a 24-bit RGB image signal (normal observation image data) in which each pixel is composed of an R image signal, a G image signal, and a B image signal, which are 8-bit brightness values, is synthesized. To.

【0046】

Subsequently, the CPU 38 reads the data (RGB image signal) of the normal observation image stored in the memory M1 and writes it to the VRAM 41 (S5). Subsequently, the CPU 38 outputs the RGB image signal stored in the VRAM 41 to the D / A converter 37 (S6). Then, the D / A converter 37 converts the RGB image signal output from the VRAM 41 into digital / analog and supplies it to the monitor 15. As a result, as shown in FIG. 5, in the display area on the left side of the monitor 15, an image of the subject (living body) when illuminated by the illumination light, that is, a normal observation image is displayed in color. In the present embodiment, the VRAM 41 outputs an RGB image signal for one screen every 1/30 second, for example, and an image based on this image signal is displayed on the monitor 15. Therefore, a normal observation image is displayed as a moving image in the display area on the left side of the monitor 15.

【0047】

The above operation is the operation during normal observation. In FIG. 5, as a normal observation image of the subject, a normal observation image including a tracheal tube empty portion A and a tracheal tube wall portion B is shown. However, although the tube wall portion B actually contains the tumor site C, the brightness distribution of the normal observation image is as shown in FIG. 6, so this tumor site C is regarded as the normal part in the normal observation image. Almost indistinguishable.

【0048】

Next, the operation of the electronic endoscope device 10 at the time of fluorescence diagnosis will be described.

【0049】

When the external switch 36a is turned on, the MIC35 of the video processor 13 detects the signal (ON signal) generated by this turning on and notifies the PC14 (CPU38) to that effect. On the other hand, the CPU 38 determines whether or not there has been a notification from the MIC35 that an ON signal has been detected each time the processing of the above S1 to S6 is completed (S7), and if not, returns the processing to S1 and if there is. In S8, the image creation process for fluorescence diagnosis is executed.

【0050】

FIG. 4 is a flowchart showing an image creation processing subroutine for fluorescence diagnosis executed in S8. Upon entering this subroutine, the CPU 38 first stores the latest obtained normal observation image data (RGB image signal) in the memory M1 (S101). Here, it is assumed that the memory M1 stores almost the same data of the normal observation image as shown in FIG.

【0051】

Subsequently, the CPU 38 gives a control command to the light source control unit 27 to operate the light source device 12 in the fluorescence observation state (S102). Then, the light source control unit 27 of the light source device 12 inserts the first mirror 25 into the optical path of the excitation light from the UV light source 24, and the excitation light reflected by the first mirror 25 is introduced to the incident end surface of the light guide 20. Move the second mirror 26 to a position where it reflects toward. Subsequently, the CPU 38 gives a control command to the MIC 35 to bring the switch piece of the switch SW into contact with the output terminal T2 and activate the amplifier 32 (S103). As a result, the MIC35 brings the switch piece of the switch SW into contact with the output terminal T2 and gives a control signal to the control terminal of the amplifier 32.

【0052】

By executing the control of S102 and S103, the excitation light emitted from the UV light source 24 is reflected by the first mirror 25 and the second mirror 26 and incident on the light guide 20. Then, this excitation light is transmitted to the tip of the electronic endoscope 11 through the light guide 20, is emitted from the exit end surface of the light guide 20, is diffused by the light distribution lens 21, and is irradiated to the subject. Then, autofluorescence is emitted from the biological tissue of the trachea, which is the subject. At this time, the intensity of the green light band component in the autofluorescence emitted from the normal part of the living tissue is higher than the intensity of the green light band component in the autofluorescence emitted from the tumor site C.

【0053】

The light from the subject including the autofluorescent light and the reflected light of the excitation light enters the objective optical system 18 and passes through the cutoff filter 19. Since this cutoff filter 19 cuts light in the ultraviolet band, only the autofluorescent component passes through the cutoff filter 19 and forms an image of the subject on the imaging surface of the CCD17. As a result, the CCD17 captures an image of the subject (living body) when irradiated with the excitation light, that is, an autofluorescent image. At this time, since the intensity of autofluorescence from the normal part of the living body is higher than the intensity of autofluorescence from the abnormal part, as shown in FIG. 9, of each pixel of CCD17, the image of the normal part is imaged. The amount of light received is larger than the amount of light received by the pixel in which the image of the tumor site C is imaged. Then, the CCD 17 outputs an image signal (F image signal) corresponding to the amount of light received by each of these pixels.

【0054】

After that, the F image signal is transmitted to the amplifier 32 through the signal line 17a and the switch SW, amplified by the amplifier 32, analog-to-digital converted by the A / D converter 33, and stored in the F memory 34. When the F image signal for one screen is stored in the F memory 34 in this way, the scan converter 36 outputs the F image signal inside the F memory 34 to the PC 14. As a result, the F image signal is accumulated in the video capture 39.

【0055】

Then, the CPU 38 stores the F image signal (autofluorescent image data) stored in the video capture 39 in the memory MF (S104). In this way, for almost the same imaging range, the memory M1 stores the data of the normal observation image (RGB image signal), and the memory MF stores the data of the autofluorescent image (F image signal).

【0056】

Subsequently, the CPU 38 determines the brightness value of the R image signal, the brightness value of the G image signal, and the brightness of the B image signal for the same pixel in the RGB image signal (normally observed image data) stored in the memory M1 at this time. By performing a predetermined matrix operation on the value, the brightness value (binary value represented by 8 bits) of the entire pixel is calculated (RGB-YCC conversion). The CPU 38 writes the luminance values (Y signals) calculated for all the pixels in this way to the memory M2 (S105). As a result, in the image signal stored in the memory M2, as shown in FIGS. 5 and 6, the brightness of the tube empty portion A is low and the brightness of the tube wall portion B including the tumor site C is high.

【0057】

Next, the CPU 38 compares the brightness value of each pixel of the image signal stored in the memory M2 with a predetermined first threshold value (indicated by a broken line in FIG. 6) and binarizes it (S106). That is, the CPU 38 rewrites all eight bits representing the luminance value of the pixel whose luminance value is lower than the first threshold value to "0". On the other hand, all eight bits representing the luminance value of the pixel whose luminance value is higher than the first threshold value are rewritten to "1". As a result, as shown in FIGS. 7 and 8, the tube empty portion A and the tube wall portion B are separated, and only the pixel corresponding to the tube wall portion B has the brightness value 11111111.

【0058】

By the way, the memory MF stores an F image signal having a distribution of luminance values (binary values represented by 8 bits) as shown in FIG. Therefore, the CPU 38 performs a logical product (AND) operation on the value of each bit that constitutes the brightness value of each pixel stored in the memory M2 and the value of each bit that constitutes the brightness value of each pixel stored in the memory MF. Is performed, and the calculation result is overwritten in the memory MF (S107). As a result, as shown in FIGS. 10 and 11, the portion of the F image signal corresponding to the empty tube A is masked, and only the portion corresponding to the remaining tube wall B (including the tumor site C) is the original. The image signal that remains in the state of is held in the memory MF. As shown in FIG. 11, the brightness value of the portion of the image signal stored in the memory MF indicating the tube wall portion B is higher in the normal region than in the tumor region C.

【0059】

Next, the CPU 38 compares the brightness value of each pixel of the image signal stored in the memory MF with a predetermined second threshold value (a value larger than the first threshold value as shown by the broken line in FIG. 11), and 2 Value (S108). That is, the CPU 38 rewrites all eight bits representing the luminance value of the pixel having the luminance value in the β region and the γ region lower than the second threshold value to 0. On the other hand, all eight bits representing the brightness value of the pixel whose brightness value exists in the α region higher than the second threshold value are rewritten to 1. As a result, only the normal portion is extracted from the tube wall portion B, and only this normal portion has the brightness value 11111111.

【0060】

Next, the CPU 38 performs an exclusive OR operation on the value of each bit constituting the brightness value of each pixel stored in the memory M2 and the value of each bit constituting the brightness value of each pixel stored in the memory MF. , Overwrites the calculation result in memory M2 (S109). As a result, as shown in FIGS. 12 and 13, an image signal indicating the shape and position of the tumor site C is held in the memory M2.

【0061】

Subsequently, the CPU 38 writes the image signal (normally observed image data) stored in the memory M1 to the area on the left side of the VRAM 41 (S110). Next, the CPU 38 is an image obtained by synthesizing a still image of a normal observation image and an image of tumor site C determined based on the intensity of autofluorescence (an image showing a specific region consisting of pixels whose brightness value belongs to the β region). (An image in which a specific area is superimposed in blue in a normal observation image) is generated. That is, the CPU 38 maps the pixels (pixels belonging to the tumor site C) whose brightness value in the image signal stored in the memory M2 is 11111111 to the memory M1, and the mapped pixels on the memory M1. Set the color to, for example, B (blue) (S111). As a result, on the memory M1, still image data of the fluorescence diagnostic image in which the region corresponding to the tumor site C (abnormal site) in the normal observation image is shown in blue is generated. Then, the CPU 38 writes the fluorescence diagnosis image data stored in the memory M1 to the area on the right side of the VRAM 41 (S112). When the entire VRAM 41 is filled with the image data as described above, the CPU 38 outputs the stored contents of the VRAM 41 (image data indicating the image to be displayed on the monitor 15) to the D / A converter 37 (S113). ..

【0062】

The stored contents of the VRAM 41 are supplied to the monitor 15 via the D / A converter 37. As a result, a still image of the fluorescence diagnostic image showing the tumor site C in blue is displayed in the display area on the right side of the monitor 15.

【0063】

After that, the CPU 38 gives a control command to the light source control unit 27 and the MIC 35 to operate the light source device 12 and the video processor 13 in the normal observation state (S114), and terminates this subroutine. Upon receiving the control command of S114, the MIC35 brings the switch piece of the switch SW into contact with the output terminal T1. Further, the light source control unit 27 retracts the first mirror 25 and the second mirror 26 from the optical paths of the illumination light and the excitation light. As a result, the electronic endoscope device 10 is returned to the state at the time of normal observation, and as shown in FIG. 14, the normal observation image displayed in the display area on the left side of the monitor 15 becomes a moving image. [Example of Use of Electronic Endoscope Device] Next, an example of use of the above-mentioned electronic endoscope device 10 will be described. First, the operator of the electronic endoscope device 10 turns on the light source device 12, the video processor 13, the PC 14, and the monitor 15. As a result, the CPU 38 of the PC 14 executes the main routine shown in FIG. 3, and the normal observation image of the subject is displayed in the display area on the left side of the monitor 15.

【0064】

Subsequently, the operator inserts the insertion portion 16 of the electronic endoscope 11 into the body cavity, and searches for the site expected to be the tumor site C while observing the normal observation image displayed on the monitor 15.

【0065】

After that, when the site expected to be tumor site C is displayed on the monitor 15 (see FIG. 5), the operator turns on the external switch 36a. Then, the CPU 38 of the PC 14 executes the image generation process for fluorescence diagnosis shown in FIG. As a result, the fluorescence diagnostic image is displayed in the display area on the right side of the monitor 15.

【0066】

At this time, if there is a region displayed in blue in the fluorescence diagnostic image, it is highly possible that the site expected to be tumor site C is actually the tumor site, and there is no area displayed in blue. It is highly possible that the site expected to be tumor site C is a normal site. Then, the operator diagnoses whether or not the site expected to be the tumor site C is actually the tumor site based on the normal observation image and the fluorescence diagnosis image. [Effect of the embodiment] According to the electronic endoscope device 10 of the present embodiment, when the operator turns on the external switch 36a at the site expected to be the tumor site C, the CPU 38 of the PC 14 has the intensity of autofluorescence. Based on the difference, the tumor site C (the site consisting of pixels whose brightness value belongs to the β region) is extracted from the autofluorescence image, and the fluorescence diagnostic image in which the tumor site C is displayed in blue is displayed on the monitor 15. Therefore, the operator can properly diagnose whether or not the site expected to be the tumor site C is actually the main site.

【0067】

Further, according to the electronic endoscope device 10 of the present embodiment, it is possible to display a fluorescence diagnostic image appropriately showing the tumor site C on the monitor 15 even if it does not have an image intensifier. Therefore, the configuration of the electronic endoscope device 10 can be simplified, and the cost can be reduced. In particular, since it is not necessary to place the image intensifier at the tip of the electronic endoscope, it is possible to prevent the tip of the electronic endoscope from becoming thick and reduce the burden on the patient. it can.

【0068】

In the present embodiment, the fluorescence diagnostic image in which the region corresponding to the tumor site (the site whose brightness value belongs to the β region in the autofluorescent image) among the normal observation images stored in the memory M1 is shown in blue. Although it was configured to be displayed on the monitor 15, the fluorescence diagnostic image showing the tumor site (the site whose brightness value belongs to the β region in the autofluorescence image) in the autofluorescence image stored in the memory MF in blue is monitored. It may be displayed at 15.

【0069】

Further, in the present embodiment, the output signal of the CCD 17 at the time of fluorescence diagnosis is amplified by the amplifier 32, but the output signal of the CCD 17 may be amplified by using frame addition in addition to the amplifier 32.

【0070】

[Effect of the invention]

According to the electronic endoscope device for fluorescence diagnosis according to the present invention, an appropriate image for fluorescence diagnosis can be obtained even without an image intensifier, and the configuration of the electronic endoscope device for fluorescence diagnosis Can be simplified and the cost can be reduced.

【0071】

[Simple explanation of drawings]

FIG. 1 is a configuration diagram of an electronic endoscope device for fluorescence diagnosis according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a PC shown in FIG. 1. FIG. 3 is a main processing by the CPU shown in FIG. Flow chart showing the routine [Fig. 4] Flow chart showing the image generation processing subroutine for fluorescence diagnosis shown in Fig. 3 [Fig. 5] Fig. 5 showing a display example of the normal observation image [Fig. 6] Graph showing the luminance distribution in the normal observation image [Fig. 6 FIG. 7 is a diagram showing a display example of a normal observation image after binarization based on the first threshold. [Fig. 8] A graph showing a luminance distribution in a normal observation image after binarization based on the first threshold [Fig. 9] Graph showing the luminance distribution in the fluorescence image [Fig. 10] Figure showing the display example of the autofluorescent image after the logical product processing [Fig. 11] Graph showing the luminance distribution in the autofluorescent image after the logical product processing [Fig. 12] No. 2 Figure showing example of display of autofluorescent image after binarization based on threshold [Fig. 13] Graph showing luminance distribution in autofluorescent image after binarization based on second threshold [Fig. 14] Displayed on monitor Diagram showing screen example [Explanation of symbols]

Ten Electronic endoscope device for fluorescence diagnosis 11 Electronic endoscope 12 Light source device 13 Video processor 14 Personal computer 17 CCD36 External switch 38 CPU