JP3228627B2 - Endoscope image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention emphasizes an endoscopic image picked up in a visible region on the basis of a signal of a pigment concentration distribution calculated by a pigment amount calculating means, and enhances the characteristics and dye density of a normal endoscopic image. The present invention relates to an image processing apparatus for an endoscope that performs image processing for obtaining an endoscope image having a distribution feature.

[0002]

2. Description of the Related Art In recent years, endoscopes capable of observing the inside of a patient's body cavity without making an incision and performing a medical treatment or the like by using a treatment tool as necessary have been widely used in the medical field. It became so. In addition, image processing may be performed on an endoscope image obtained by an endoscope to facilitate identification of a normal part or a lesion part by performing image processing. .

[0003] As a prior example of performing image processing on an endoscope image, RG as disclosed in Japanese Patent Application Laid-Open No. 62-266028 has been proposed.
A method of converting a B image into hue, saturation, and brightness, and then performing an enhancement process on each parameter.
The method of extending or moving the histogram of hue, lightness, and saturation as in Japanese Patent No. 54144, or calculating the amount of hemoglobin as in Japanese Patent Publication No. 5-3295,
There was a method of imaging.

Further, as disclosed in Japanese Patent Application Laid-Open No. 224635/1990, a process of obtaining a difference between color-separated images and emphasizing the difference based on the information is performed.

[0005]

However, Japanese Patent Application Laid-Open Nos. Sho 62-266028 and 63-54144 disclose the problems.
Since the processing method disclosed in Japanese Patent Application Laid-Open Publication No. H10-107421 aims at enhancement processing that matches human vision, for example, when color enhancement is performed, all subtle changes in color are emphasized, so that the contrast is too strong and long. The image was unsuitable for time observation.

Further, in the method of imaging the amount of hemoglobin as disclosed in Japanese Patent Publication No. 5-3295, comparison with an endoscope image taken in a normal visible region is required. In other words, the image according to this publication is a two-dimensional pattern image in which the outline or the three-dimensional structure of the affected part or the like is not known, so that the position or shape of the affected part or the like can be confirmed by comparison with a normal endoscopic image. It will be essential to do. In this case, if both images cannot be displayed at the same time, there is a drawback that it is difficult to confirm the position and the shape.

On the other hand, in the processing method disclosed in Japanese Patent Application Laid-Open No. 224635/1990, the possibility of obtaining an image having the characteristics of biological function information and a normal endoscopic image cannot be denied at all, but the diagnosis is not possible. Obtaining an image with suitable features becomes very difficult.

That is, in this publication, image enhancement is performed by, for example, multiplying a color signal and a difference signal which is substantially proportional to the amount of hemoglobin, so that the characteristics of a normal endoscopic image are greatly deformed by the amount of hemoglobin. Often it is. Therefore, for example, the color of the affected part can be changed so as to be conspicuous, but the color tone also changes in the normal part, so that it is difficult to grasp the part to be focused on, such as the affected part. Image does not appear.

Generally, a normal site (referred to as a normal site)
An image that is easy to detect at the initial part of the lesion (hereinafter referred to as the initial part of the lesion) having characteristics that are slightly different from the state described above is an image having characteristics suitable for diagnosis. In this case, it is desired that the normal part also has a feature that hardly changes from the color tone of the normal endoscopic image in order to easily identify the initial part of the lesion.

That is, an image processing apparatus which performs image processing for providing an image having a characteristic color that makes a lesion part conspicuous with a color tone of a normal endoscopic image for most parts is diagnosed. It becomes suitable for.

For this reason, it is necessary to improve the prior art of the above-mentioned publication so as to provide an image suitable for diagnosis with the features of both images.

The present invention has been made in view of the above points, and has been made in consideration of the above-described problems, and has been made in consideration of the above-described problems, and is provided with an image processing apparatus for an endoscope capable of obtaining an endoscope image having characteristics suitable for diagnosis based on biological function information such as hemoglobin dye. It is intended to provide a device.

[0013]

The present invention provides imaging means for imaging a subject image, dye amount distribution calculating means for obtaining at least one dye amount distribution from an image obtained by the imaging means, and After replacing the dye amount with a dye amount obtained by enlarging the amount of deviation from the reference value, comprising an emphasis means for enhancing the image by converting to an endoscope image having the replaced dye amount, By replacing higher values with higher dye amounts, lower values below the reference values with lower dye amounts, and then returning to the endoscopic image to obtain an image-enhanced endoscopic image, An endoscopic image having characteristics of an endoscopic image and having a feature in which a lesion is emphasized so as to stand out is obtained.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an endoscope apparatus 1 provided with the present embodiment includes an electronic endoscope 2 provided with an imaging unit, and a video processor which supplies illumination light to the electronic endoscope 2 and performs signal processing. 3, a monitor 4 for displaying a video signal output from the video processor 3, and a video processor 3
And an image filing device 5 for performing image processing and filing an image. The image filing device 5 enhances an image signal output from the video processor 3.
Built-in.

The electronic endoscope 2 has a slender, for example, movable insertion section 7, and a wide-width operation section 8 is connected to the rear end of the insertion section 7. A flexible universal cord 9 extends from the rear end side of the operation unit 8, and a connector 11 is provided at an end of the universal cord 9.

On the distal end side of the insertion portion 7, a rigid distal end portion 12 and a bending portion 13 which can be bent rearward adjacent to the distal end portion 12 are sequentially provided. Further, by rotating the bending operation knob 14 provided on the operation unit 8,
The bending portion 13 can be bent in the horizontal direction or the vertical direction. Further, the operation section 8 is provided with an insertion port 15 communicating with a treatment instrument channel provided in the insertion section 7.

As shown in FIG. 2, an illumination lens 16 and an objective optical system 17 are attached to the illumination window and the observation window at the distal end portion 12, respectively. A light guide 18 made of a fiber bundle is provided on the rear end side of the illumination lens 16.
The light guide 18 is provided with the insertion portion 7,
The operation unit 8 is inserted through the universal cord 9 and is connected to the connector 11.

By connecting the connector 11 to the video processor 3, the illumination light emitted from the light source device 3 A in the video processor 3 is input to the light guide 18 at the incident end. ing.
The light source device 3 </ b> A includes a lamp 19, a rotary filter 21 disposed in an illumination optical path of the lamp 19 and rotated by a motor 20, and a rotary filter 21 and the lamp 19.
And

The lamp 19 emits light from ultraviolet to infrared. The rotation filter 21 includes:
The color transmission filters 21a, 21b, 21c that transmit light in different wavelength ranges are arranged along the circumferential direction. The color transmission filter 2 of the rotation filter 21
The characteristics of 1a, 21b, and 21c are set to the characteristics that pass the respective wavelength ranges of R, G, and B shown in FIG.

The light emitted from the lamp 19 is time-separated into each wavelength region by the rotary filter 21 and is incident on the incident end of the light guide 18. The illumination light is guided to the distal end portion 12 by the light guide 18, and can illuminate the subject such as the inspection site 45 through the illumination lens 16 attached to the illumination window on the distal end surface.

On the other hand, at the image forming position of the objective optical system 17, for example, a CCD 23 is provided as a solid-state image pickup device. Then, the subject image illuminated by the surface-sequential illumination light is formed on the photoelectric conversion surface of the CCD 23 by the objective optical system 17, and is converted into an electric signal by the CCD 23. The image signal from the CCD 23 is input into the signal processing circuit 3B, and is input to an amplifier 24 for amplifying the electric signal within a predetermined range (for example, 0 to 1 volt).

The electric signal output from the amplifier 24 is γ-corrected by a γ-correction circuit 25, and then converted into a digital signal by an A / D converter 26.
7 is input. The RGB signals transmitted in time series are separated into R, G, and B color signals by the selector 27 and input to the memory unit 28.

The separated R, G, B color signals are stored in R, G, B memories 28r, 28g, 28b of the memory unit 28 corresponding to R, G, B, respectively. The color signals R, G, B read from the memories 28r, 28g, 28b are respectively converted into analog three primary color signals R, G, B by the D / A converters 29r, 29g, 29b of the D / A converter 29. To switch SW
Are output to the monitor 4 from the R, G, and B signal output terminals.

The synchronizing signal S from the synchronizing signal generation circuit 30 is output from the synchronizing signal output terminal together with the three-color original signals R, G, and B. Then, the three primary color signals R, G, B and the synchronization signal S are output to the monitor 4 via the switch SW1. The three primary color signals R, G, B and the synchronizing signal S are supplied to the switch SW2 in the image filing device 5.
Is input to the image recording / reproducing unit 5A.

The signal processing circuit 3B is provided with a control signal generator 31. The control signal generator 31 converts the A / D converter 26, switches the selector 27,
In addition to the control signals for controlling the timing of writing / reading of the 8r, 28g, 28b and the conversion of the D / A converters 29r, 29g, 29b, control signals are also sent to the synchronization signal generating circuit 30 and the motor 20, respectively. I have.

In the image filing device 5, by inputting a file name or the like for recording from the keyboard 5C of the front panel 5B, the endoscope image data is recorded in the recording / reproducing unit 5A with the designated file name.
In order to instruct reproduction, when a file name is input from the keyboard unit 5C, the endoscope image data having the specified file name is read and input to the image enhancement unit 6. When image enhancement is performed by the image enhancement unit 6, an instruction for an enhancement amount is further issued from the keyboard unit 5C or the selection switch unit 5D of the front panel 5B. The emphasis may be performed with a preset default value without performing this instruction.

The emphasis processing as shown in FIG. 6 is performed by the image emphasis unit 6, and the emphasized endoscope image data is recorded in the image recording / reproducing unit 5A via the switch SW2, or the video processor. 3 can be output to the monitor 4 via the switch SW1 to display an enhanced endoscope image.

The image enhancement unit 6 calculates the distribution of the amount of hemoglobin (abbreviated as IHb) as the amount of dye for the three primary color signals R, G, and B input in synchronization with the synchronization signal.
That is, the distribution of the hemoglobin density is calculated, the density is enhanced, then converted into three primary color signals R ', G', and B ', and the video signal emphasized with the amount of hemoglobin is output together with the synchronizing signal S together with the output signal. Output from

The three primary color signals R ', G',
B 'is recorded by the image recording / reproducing unit 5A, and is output to the monitor 4 via the contact b of the switch SW1. The monitor 4 receives one of the unenhanced video signal and the enhanced video signal by selecting the switch SW1, and the corresponding unenhanced or enhanced endoscopic image is input by the input video signal. Is displayed.

FIG. 4 is a block diagram showing the configuration of the image enhancement unit 6 . As shown in FIG. 4, in the image emphasizing unit 6, 3 sent from the image recording / reproducing unit 5A is transmitted.
A / D for converting primary color signals R, G, B into digital signals
Converters 32a to 32c are provided. The controller 40 controls the acquisition of the three primary color signals R, G, and B by the A / D converters 32a to 32c in synchronization with the input synchronization signal S.

The three primary color signals R, G, and B converted into digital signals are subjected to inverse gamma correction conversion by look-up tables (hereinafter abbreviated as LUTs) 33a to 33c provided at the subsequent stage, and logarithmically converted by LUTs 34a to 34c. Is converted. A matrix circuit 35 for calculating the amount of hemoglobin is provided at a stage subsequent to the LUTs 34a to 34c.
Further, a ROM 36 and an average value calculation circuit 37 are provided at a subsequent stage.

The signal passed through the average value calculation circuit 37 is stored in a ROM
36, and the enhancement coefficient is calculated. The signal passed through the ROM 36 is transferred to a ROM 38 for adjusting the amount of emphasis by weighting coefficient data WD determined by the operator through the front panel 5C. The operator can variably set the weighting coefficient WD by operating the selection switch section 5D or the like of the front panel 5C so that the operator can set the degree of emphasis and color tone of the operator's preference.

LUTs 33a to 33c are provided in ROMs 39a to 39c for converting an emphasized image provided at a stage subsequent to the ROM 38.
A signal line transmitted from the controller is connected via a frame memory 41 for timing adjustment. In the latter stage, D / A
Converters 42a to 42c are connected, and the D / A converted analog signal is output to the image recording / reproducing unit 5A in the image filing device 5, and is also output to the monitor 4 via the switch SW1 in the video processor 3. .

FIG. 5 shows a schematic configuration of the image enhancing unit 4 shown in FIG. The color signals R, G, and B are converted into color signals having linear characteristics by the inverse γ correction circuit 46, and then input to the conversion unit 47 and input to the IHb calculation unit 48. The IHb calculation unit 48 calculates IHb for each pixel from the color signal having a linear characteristic.

That is, the concentration distribution data of IHb is calculated. Further, an average value <IHb> of the density is obtained. The density distribution data is generated such that IHb is emphasized by the emphasis unit 49 with respect to the deviation amount from the average value <IHb>. After that, the enhanced density distribution data is converted by the conversion unit 47 into a color signal in which the amount of deviation of the IHb from the average value of the color signal is enhanced. This color signal is converted by a gamma correction circuit 50 into color signals R ',
It is output as G ', B'. The emphasis unit 49 performs emphasis according to the emphasis amount setting data from the emphasis amount setting unit 49A.

In this embodiment, after calculating the IHb density distribution data from the original image as shown in FIG. 5, the IHb density distribution data is not directly emphasized by the calculated IHb density distribution data. After emphasizing the distribution (emphasizing the density distribution with respect to the deviation from the average value of IHb), converting the original image to have the emphasized IHb density distribution (replace the IHb of the original image with the emphasized IHb) As a result, it is characterized in that an image in which the IHb density distribution is emphasized by the amount of deviation from the average value with respect to the original image is generated or calculated.

Accordingly, as can be seen from this processing, the endoscope image obtained by this embodiment is a normal endoscope image (R, R) for most normal parts having an average value of IHb.
It has the characteristics of an endoscopic image captured in the visible region of G and B), and has a concentration distribution of IHb in which a dye amount portion (a portion likely to be abnormal) in which IHb deviates from the average value stands out. An enhanced image with features will be obtained.

Next, an endoscope apparatus 1 having the first embodiment will be described.
The operation of will be described below. First, as shown in FIG. 1, the electronic endoscope 2, the video processor 3, the monitor 4, and the image filing device 5 are connected, the insertion section 7 of the electronic endoscope 2 is inserted into the living body 44, and The inspection site 45 is set at a position where it can be observed. In this state, the light source device 3 shown in FIG.
Illumination light in the visible wavelength ranges of A to R, G, and B is supplied to the proximal end face of the light guide 18 of the electronic endoscope 2, and the illumination light is transmitted and emitted forward from the end face on the distal end portion 12 side. Then, the inspected portion 45 is sequentially illuminated with each of the R, G, and B lights.

The illuminated inspection part 45 is imaged on the photoelectric conversion surface of the CCD 23 by the objective optical system 17 attached to the observation window, and the image signal photoelectrically converted from the CCD 23 is
That is, an image signal corresponding to the endoscope image is output to the signal processing circuit 3B of the video processor 3. The signal processing circuit 3B performs a process of generating a standard video signal, and generates three primary color signals R, G, and B.

When the switch SW is set to the contact a side, the endoscope image captured in the visible region is displayed as the three primary color signals R, G, and B. The three primary color signals R, G, and B are stored in an image recording / reproducing unit 5A of the image filing device 5.
And the endoscope image data captured in the visible region is recorded.

When the endoscope image data recorded in the image recording / reproducing unit 5A is instructed to reproduce and the emphasis processing is instructed, it is input to the image emphasizing unit 6 as shown in FIG. Processing is performed.

The parameters are set as shown in step S1. In this case, the emphasis processing such as input of the file name of the image data to be reproduced and emphasized from the keyboard section 5C of the front panel 5B, ON / OFF of the selection switch section 5D or the like, or designation of the emphasis weight coefficient WD from the keyboard section 5C. Enter the required data for. Next, step S2
The designated RGB image data is input to the image enhancement unit 6 as shown in FIG. That is, the image data of the input file name is read from the image recording / reproducing unit 5A to the image enhancing unit 6.

Since the read image data has been subjected to gamma correction for making the input / output characteristics of the monitor 4 linear, inverse gamma correction is performed as shown in step S3 to convert the image data into linear data. I do.

Thereafter, as shown in step S4, the hemoglobin amount (IHb) is calculated. The amount of hemoglobin, which is functional information of the living tissue, is calculated for each pixel. Therefore,
The density distribution of IHb in the RGB image is calculated. Then, as shown in step S5, the average value of the hemoglobin amount for one screen is obtained for the effective pixel, and a new hemoglobin amount is determined for each pixel based on the average value.

When calculating a reference value such as an average value of the hemoglobin amount, for example, a portion (halation, dark portion, stained portion,
The calculation is performed excluding foreign substances other than the living body such as forceps. Further, as shown in step S6, the IHb 'emphasized from the IHb using the weighting coefficient WD and the average value of the emphasis input first.
, That is, a data conversion process for converting the data into an enhanced IHb 'density distribution.

After calculating the emphasized IHb ', as shown in step S7, a process of creating an enhanced image for returning to the RGB image data using the IHb' is performed. That is, image data is created in which the amount of hemoglobin that deviates from the average value of the amount of hemoglobin is enhanced with respect to the image data that has been subjected to the inverse γ correction.

The enhanced image data is further subjected to γ correction as shown in step S8, and step S9
The image data is output as an image file as shown in FIG. This image file is recorded on the image recording / reproducing unit 5A or output to a display device such as the monitor 4.

Here, the method for calculating the amount of hemoglobin and the method for calculating the average value (steps S4 and S5 in FIG. 6) will be described with reference to the flowchart in FIG. Image 2
When represented by a dimensional array IM (X, Y), X means the image size in the X direction, and Y means the image size in the Y direction.
R (i, j) is the luminance level of the R signal at the position (i, j), G (i, j) is the luminance level of the G signal at the position (i, j), and IHb (i, j) is the position Let it represent the hemoglobin amount at (i, j). AVGIHb is 1
It represents the average value of the hemoglobin amount for the screen.

First, an initial setting as shown in step S11 is performed. A variable i indicating a position in the X direction, a variable j indicating a position in the Y direction, and AVGIHb are initialized (0 is substituted). Next, a process of calculating the hemoglobin amount of each pixel is performed in the following steps S12 to S19.

(1) A value obtained by multiplying the logarithmic ratio of R (i, j) and G (i, j) by a coefficient 32 is substituted for IHb (i, j) (step S12).

(2) AVGIHb = AVGIHb + IH
b (i, j) is executed (step S13). (3) i is counted up by 1 (step S14).

(4) It is determined whether or not i ≧ X (step S)
15) If i <X, return to the process of (1); if i ≧ X, execute (5). (5) j is counted up by 1 (step S16).

(6) It is determined whether or not j ≧ Y (step S)
17) If j <Y, the process returns to the process of (1) via step S18 of i = 0, and if j ≧ Y, (7) is executed. (7) Execute AVGIHb = AVGIHb / (X + Y) (step S19).

With the above steps, the calculation of the hemoglobin amount and the calculation of the average value are performed.

Next, a method of creating an emphasized image will be described with reference to the flowchart of FIG. IHb '(i, j)
Represents the newly determined amount of hemoglobin at the position (i, j), εr, εg, εb represent the extinction coefficients of hemoglobin in the R, G, and B filter bands, respectively, and αr (i, j), αg (I, j) and αb (i, j) are the enhancement coefficients of the R, G, and B images at the position (i, j).

Further, R '(i, j), G' (i, j),
B ′ (i, j) is a newly determined position (i, j).
The luminance levels of R, G, and B in j). The enhanced image creation processing is performed by the following steps.

(1) Initialize i = 0 and j = 0 (step S21). (2) Calculate IHb '(i, j) (Step S2)
2). Details will be described later.

(3) αr (i, j) = εr · (IHb
(I, j) −IHb ′ (i, j)) / (εg−εr) αg (i, j) = εg · (IHb (i, j) −IHb ′)
(I, j)) / (εg−εr) αb (i, j) = εb · (IHb (i, j) −IHb ′)
(I, j)) / (εg−εr) is executed (step S23).

(4) R ′ (i, j) = R (i, j) · 1
0 ＾ (αr (i, j)) G ′ (i, j) = G (i, j) · 10 ＾ (αg (i, j)) B ′ (i, j) = B (i, j) · 10 ＾ (αb (i, j)) is executed (step S24).

(5) i is counted up by 1 (step S25). (6) It is determined whether or not i ≧ X (step S26).
If <X, the process returns to (1), and if i ≧ X, the process of (7) is executed. (7) j is counted up by 1 (step S27).

(8) It is determined whether or not j ≧ Y (step S)
28) If j <Y, the process returns to the process of (2) via step S29 of i = 0, and if j ≧ Y, the process proceeds to the next process. Through the above steps, enhanced image data that is enhanced according to the amount of hemoglobin is created. Here, the equations used in the processing of the above steps will be described. All of these equations are derived from Lambert-Beer's law.

I 0 is the irradiation light amount, l is the optical path length, c (i,
j) and c ′ (i, j) are the hemoglobin concentration at the position (i, j), and As is a correction term such as scattering, and the hemoglobin concentration of the living body is changed from c (i, j) to c ′ (i, j). Then R (i, j) changes to R '(i, j)
According to Lambert-Beer's law, Log (I0 / R (i, j)) = εr · lc (i, j) + As (1) Log (I0 / R ′ (i, j)) = εr · 1 · c ′ (i, j) + As (2) is obtained.

From the above equations (1) and (2), R ′ (i, j) = R (i, j) · 10 ＾ (εr · l · (c (i, j) −c ′ (i, j))) ... (3), and the equation (3) is obtained.

Here, IHb (i, j) = (εg−εr) · lc (i, j) (4) IHb ′ (i, j) = (εg−εr) · lc '(I, j) (5) From the equations (4) and (5), R ′ (i, j) = R (i, j) · 10 ＾ (εr · (IHb (iH , j) −IHb ′ (i, j)) / (εg−εr)) (6)

G ′ (i, j) = G (i, j) · 10 ＾ (εg · (IHb (i, j) −IHb ′ (i, j)) / ( (εg−εr)) (7) B ′ (i, j) = B (i, j) · 10 ＾ (εb · (IHb (i, j) −IHb ′ (i, j)) / (εg −εr)) (8) is obtained.

In this way, the new hemoglobin amount IH
If b ′ is determined, the hemoglobin amount IH in the original image
An image obtained by converting b (i, j) into IHb '(i, j) is obtained. That is, the position (i,
If the amount of hemoglobin in j) is calculated, IHb '
(I, j) is obtained.

The amount of hemoglobin IHb '(i, j)
Is determined as an average value A of hemoglobin in an image.
Pixels having a value larger than VGIHb are converted into a larger hemoglobin amount, and pixels having a value smaller than AVGIHb are converted into a smaller hemoglobin amount. If K is a variable coefficient, then IHb '(i, j) = (IHb (i, j) -AVGIHb) .K + AVGIHb (9)

Here, the average value is used as the reference value.
A fixed value such as a result of previously collecting data on the amount of hemoglobin in a living tissue in an experiment or the like may be used. Also,
IHb '(i, j) may be set to be larger than the hemoglobin amount of the original image.

Next, the operation of image enhancement will be described with reference to the configuration of FIG. The signals sent from the image recording / reproducing unit 5A are converted into digital signals by A / D converters 32a to 32c. RG converted to digital signal
The B signal is subjected to inverse γ correction conversion by the LUTs 33a to 33c, and the frame memory 41 and the LUTs 34a to 34c
Sent to

The LUTs 34a to 34c perform logarithmic conversion which is a pre-process for performing step S12 in the hemoglobin calculation process of FIG. After each of the color signals R, G, and B is logarithmically converted, the matrix circuit 35 performs a process (or step S4 in FIG. 6) corresponding to step S12 in the hemoglobin calculation process in FIG.
Calculate Hb.

The calculated dye amount is sent to an average value calculation circuit 37, which performs a process corresponding to step S19 in FIG. 7 to calculate the average value AVGIHb data of the hemoglobin amount. The calculated AVGIHb data and the dye amount data output from the matrix circuit 35 are sent to the ROM 36, and the ROM 36
Then, based on the dye amount and the AVGIHb data, the IH for calculating the emphasized IHb '(or step S22 in FIG. 8) in step S6 in FIG.
Perform b conversion processing.

The IHb 'calculated by the ROM 36 is
Data conversion corresponding to step S23 in FIG. 8 is performed by the ROM 38, and the data is transferred to the ROMs 39a to 39c. RO
In M39a to 39c, the frame memory 41 performs data conversion corresponding to step S7 in FIG. 6 or step S24 in FIG. 8 from the RGB signals adjusted in timing and αa, αb, and αc calculated by the ROM 38.

In the ROMs 39a to 39c, γ
Correction is also performed. The R'G'B 'image signal created here is converted into an analog signal by the D / A converters 42a to 42c and then recorded by the filing unit 5A, and at the same time, the contact point of the switch SW1 in the video processor 3. The information is displayed on the monitor 4 via the terminal b. In this embodiment, R
Although the data conversion is performed using the OM or the matrix circuit, the processing may be performed using a field programmable gate array or the like instead of the ROM or the matrix circuit.

According to the present embodiment, it is possible to display a portion having a lot of blood as having more blood and a portion having a little blood as having less blood. It is possible to more effectively and naturally express a portion where the blood flow state is changing from the surrounding mucous membrane, for example.

The following advantages are provided. In this embodiment, the density distribution of IHb is calculated with respect to the endoscope image captured in the visible region, the average value is calculated, and each IHb is expanded so as to be enlarged by the amount of deviation from the average value. Since the emphasis process for converting the image into the replaced endoscope image is performed, the lesion in the initial state, such as redness, where the IHb slightly deviates from the average value, starts from the average value portion (that is, the majority of the normal portion portion). The image becomes conspicuous. For this reason, the lesion can be identified at an early stage, and the possibility of the operator overlooking the lesion can be reduced,
Since the lesion can be easily found, the burden on the operator can be reduced.

Further, since the lesion can be identified at an early stage, the treatment is facilitated. In addition, since the average value portion is not emphasized, the normal portion corresponding to the average value portion has the same color tone as that captured in a normal visible region, so that an enhanced endoscopic image suitable for diagnosis without discomfort can be obtained. . Also,
Since the image has a three-dimensional effect, comparison with a normal endoscope image is not indispensable.

That is, in the normal endoscopic image, only the portion having the IHb changed from the IHb of the normal part is emphasized, and the other images having the characteristics of the normal endoscopic image can be obtained. Therefore, it is possible to provide an image that has a merit that a lesion site can be identified from only an image subjected to enhancement processing without comparing with a normal endoscopic image, and that is very effective for diagnosis.

In the first embodiment, there is also a merit that an image having the above-mentioned merits can be obtained by calculating IHb from an endoscope image taken in a normal visible state. In other words, since images taken in a special wavelength range are not used,
By adding the image enhancement unit 6 to an endoscopic image already recorded in an existing endoscopic image recording device or the like, it is possible to obtain an enhanced image having the above-described advantages and suitable for diagnosis. Is possible. Therefore, it is possible to provide a doctor with a diagnostic assistance device having a wide application range.

In the above embodiment, the image is not affected by the dye or the like. However, the image of the part stained with the dye such as methylene blue is adjusted so that the hemoglobin amount IHb = 0. Since it is set, it is emphasized with the same emphasis coefficient as that of the portion where IHb does not exist.

Furthermore, a conversion formula that makes the emphasized hemoglobin amount converge to 0 may be used. Further, since the hemoglobin amount IHb of the portion stained with methylene blue or the like has a negative value, an image in which the staining is enhanced can be obtained by performing the enhancement processing as it is. Further, in the first embodiment, the calculation is performed separately for the absorption coefficients in the G and B wavelength regions of hemoglobin. However, the calculation may be simply performed with the same absorption coefficient.

As described above, according to the first embodiment, it is possible to display a portion with a large amount of blood as having more blood and a portion with a small amount of blood as having less blood.
It is possible to emphasize a part where the blood flow state changes from the surrounding mucous membrane, such as a blood vessel part or a lesion part, and obtain an image in which the lesion part can be easily identified. And it is possible to express naturally. Therefore, it is effective when diagnosing a blood flow condition,
It is also effective in preventing the lesion from being overlooked.

FIG. 9 shows an endoscope apparatus 5 according to a modification of the first embodiment.
1 is shown. In this modified example, in FIG. 1, the image filing apparatus 5 does not include the image enhancement unit 6, but performs the enhancement processing shown in FIG. 6 (or the enhancement processing shown in FIGS. 7 and 8) by software.
52 is built-in. Others are the same as the first embodiment. The operation of this modification is the same as the operation described with reference to FIG. 6 (or FIGS. 7 and 8), and a description thereof will be omitted.

In this modified example, obtaining an enhanced endoscope image requires more time than in the first embodiment, but otherwise provides the same effect. On the other hand, the first embodiment has an advantage that an endoscopic image that has been enhanced in almost real time can be obtained.

Next, a second embodiment of the present invention will be described. The endoscope apparatus of this embodiment has the same hardware configuration as the modification of the first embodiment (the hardware configuration is the same as that of FIG. 9), and only the hemoglobin amount calculation processing and the emphasized image creation processing are calculated. (Or processing content) is different. In this embodiment, it is possible to obtain an image enhanced by either IHb in which the dye is not taken into consideration or IHb in which the dye is taken into consideration.

The calculation of the amount of hemoglobin will be described with reference to FIG. The amount of hemoglobin IHb (i, j) is calculated in the same manner as in the first embodiment and its modified example, and the amount of hemoglobin taking into account the staining pigment is calculated as IHbb.
When expressed by (i, j), (IHbb)
Perform (i, j) calculations.

Initialization is performed as shown in step S11 'of FIG. This step S11 'is the same as step S11 in FIG.
Corresponds to 11. Next, as shown in step S12 ',
The following calculation is performed.

IHb (i, j) = 32 Log 2 (R (i, j) / G (i, j)) IHbb (i, j) = 32 Log 2 (R (i, j) / B (i, j)) (10) That is, in step S12 of FIG. 7, the calculation of the expression (10) is also performed.

Next, as shown in step S13 ', a calculation for obtaining the following average value is performed. AVGIHb = AVGIHb + IHb (i, j) AVGIHbb = AVGIHbb + IHbb (i, j) (11) That is, in step S13 of FIG. 7, the calculation of the expression (11) is also performed. The same processing as that of FIG. 7 is performed in steps S14 to S18, and an average value is obtained by the following calculation as shown in step S19 '.

AVGIHb = AVGIHb / (X + Y) AVGIHbb = AVGIHbb / (X + Y) (12) That is, in step S19 of FIG. 7, the calculation of the expression (12) is also performed. Next, a method of creating an emphasized image will be described with reference to the flowchart of FIG.

For R (i, j) and G (i, j), the same processing as in the first embodiment is performed. Step S2
After initializing the variables (i = 0, j = 0) with I, IHb '(i, j), IHb'b as shown in step S22'
Calculate (i, j). IHb '(i, j) is calculated by the above equation (5). IHb'b (i, j) is calculated from the following equation.

IHb′b (i, j) = (IHbb (i, j) −AVGIHb) · K + AVGIHb (13) Next, as shown in step S23 ′, the enhancement coefficient αr
(I, j), αg (i, j), αb (i, j) are calculated using the extinction coefficients εr, εg, εb, and the like.

Αr (i, j) = εr / (εg−εr) · (IHb (i, j) −IHb ′ (i, j)) αg (i, j) = εg / (εg−εr) · ( IHb (i, j) −IHb ′ (i, j)) αb (i, j) = εb / (εb−εr) · (IHbb (i, j) −IHb′b (i, j)) (14) The emphasis coefficients αr, αg, α in step S23 in FIG.
The only difference from b is αb shown in equation (14).

Next, the emphasis coefficient α obtained in step S23
Using r, αg, and αb, the emphasized image data is calculated as shown in step S24. R ′ (i, j) = R (i, j) · 10 ＾ (αr (i, j
j)) G ′ (i, j) = G (i, j) · 10} (αg (i,
j)) B ′ (i, j) = B (i, j) · 10 ＾ (αb (i,
j)) These expressions are the same in the same expression as step S24 in FIG.

Step S24 and subsequent steps are the same as in the first embodiment. According to this embodiment, the same effect as that of the modification of the first embodiment can be obtained, and hemoglobin can be effectively emphasized even in an image stained in a living body with a stain dye, mainly methylene blue. It is.

Note that, after the processing of FIG. 10, FIG. 11 and FIG.
May be selected. In this case, it is possible to deal with both images stained with the dye and images not stained.

In this embodiment, the calculation of the average value is performed. In this embodiment, both IHb and IHbb are calculated so that the image stained with the dye can be effectively emphasized with the amount of hemoglobin. , IHb or IHbb. As described in the first embodiment, a fixed value may be used instead of the average value.

FIG. 12 shows an endoscope apparatus 60 according to the third embodiment. The endoscope device 60 includes an endoscope device 51 shown in FIG.
In the configuration, the image enhancement unit 61 is provided.
An image enhancement unit 61 is provided downstream of the video processor 3. The output signal of the video processor 3 is input to the image enhancement unit 61, after which the image is enhanced, and then input to the monitor 4 and the image filing device 5. The image filing device 5 of FIG.
2 is not built in.

FIG. 13 shows the structure of the image enhancement unit 61. The image enhancement unit 61 is different from the image enhancement unit 6 of FIG. 4 in that a selection switch unit 62 is provided on the front panel. The combination of the switches Sa to Sd of the selection switch unit 62 with respect to the ROM 38 causes the ROM 38 to operate. Different weighting coefficients WD can be input. Reference numeral 11 denotes a light source circuit, and output light is output from the light distribution lens 10 through a light guide 9 for guiding light to the distal end of the endoscope.

The matrix circuit 35 'of the image enhancement unit 61 calculates both the hemoglobin dye amount IHbb taking into account the dye in the second embodiment and the normal hemoglobin dye amount IHb. It is possible to calculate a dye-weighted image when the dye is taken into consideration.

On the other hand, the switch Se of the selection switch section 63
Is turned off, for example, the normal hemoglobin pigment amount I
Only Hb is calculated, and a dye-weighted image can be calculated when the dye is not taken into account. Other configurations are the same as those in FIG.

According to this embodiment, the same effect as that of the first embodiment can be obtained, and the image emphasized in real time can be displayed on the monitor 4.
It is possible to display such as. It is also possible to obtain a dye-emphasized image in the case where the dye is taken into consideration and the case where the dye is not taken into account.

In this embodiment, data conversion is performed using a ROM or a matrix circuit. However, processing may be performed using a field programmable gate array or the like instead of the ROM or the matrix circuit. In the present embodiment, the enhancement processing of the RGB image is performed based on the pigment information of hemoglobin. However, the enhancement processing may be performed based on the information of the dye or the fluorescent agent.

FIG. 14 is a block diagram showing a configuration of an image enhancement unit 61 according to a modification of the third embodiment of the present invention. The endoscope apparatus of this modification has the same configuration as that of the third embodiment, and differs only in the internal configuration of the image enhancement unit 61.

As shown in FIG. 14, the image enhancement unit 6
1 includes RGB sent from the video processor 3
A / D converter 32 for converting a signal into a digital signal
a to 32c are provided. The RGB signals converted into digital signals are provided in LUTs 33a to 33 provided at the subsequent stage.
The inverse γ correction is performed by c. LUTs 33a to 33c
The data is converted by the LUTs 64 a to 64 c and sent to the line memory 63.

A difference circuit 65 is provided at a stage subsequent to the LUTs 64a to 64c so that a difference between RGB signals can be obtained. Further in the subsequent stage, the ROM 66
a to 66c are provided. These ROMs 66a-6
6 c, the emphasis processing data conversion is performed by the RGB signal whose timing is adjusted by the line memory 63 and the signal from the difference circuit 65.

The image data subjected to the data conversion for the emphasis processing is converted into analog signals by the A / D converters 42a to 42c, displayed on the monitor 4, or transferred to the image filing device 5 and recorded. Further, the controller 40 performs A / A based on the input synchronization signal S.
It controls the D converter 32a and the like and outputs the emphasized R ', G', and B 'signals in synchronization with the synchronization signal S. next,
The operation of the modification will be described.

A / D converters 32a-32c
The RGB signal is converted into a digital signal by the video processor 3, and the LUTs 33 a to 33 c perform inverse γ correction. After that, the first LUTs 64a to 64c
Calculation of Hemoglobin Amount in Example (Step S in FIG. 7)
12 or R, G, B corresponding to step S4) in FIG.
Performs logarithmic transformation of the image. The digitally converted signal is sent to a line memory 63, and the timing of the signal is adjusted to a signal passing through a difference circuit 65 and the like.
a to 66c.

The difference between the R and G logarithmically converted signals of the signals converted by the LUTs 64a to 64c is calculated by the difference circuit 65. This value corresponds to IHb in the hemoglobin calculation process of the first embodiment. The calculated IHb is sent to the ROMs 66a to 66c, and is subjected to the enhanced image creation processing of the first embodiment (step S6 in FIG. 6 or step S2 in FIG. 8).
Data conversion corresponding to 2) is performed.

In this modification, the average value is not calculated, and the average value is calculated based on a certain reference value obtained in advance through an experiment or the like.
Hb 'is calculated. The R'G'B 'images created in the ROMs 66a to 66c are stored in the D / A converter 62a.
After being converted into an analog signal by .about.62c, it is transferred to the monitor 4 or the image filing device 5.

In this modification, data conversion is performed using a ROM or a differential circuit. However, a field programmable gate array (FPG) is used instead of the ROM or the differential circuit.
It is also possible to perform processing using A) or the like. Further, the circuit of the present modified example may be incorporated in the video processor 3 or the image filing device 5 without being configured as an image enhancing unit. According to the present modification, the same effect as that of the first embodiment can be obtained, and it can be realized with a simple circuit configuration.

FIG. 15 is a block diagram showing the structure of the image enhancement unit 61 according to the fourth embodiment of the present invention. The endoscope apparatus of the present embodiment has the same configuration as that of the third embodiment, and differs only in the internal configuration of the image enhancement unit 61.

As shown in FIG. 15, the image enhancement unit 6
In the 1, good video processor 3 Ri R sent the incoming RG
A / D converter 3 for converting B signal to digital signal
2a to 32c are provided.

The RGB signals converted into digital signals are subjected to inverse γ correction conversion in LUTs 33a to 33c provided at the subsequent stage, and are logarithmically converted in LUTs 34a to 34c. The signals subjected to the inverse γ correction conversion in the LUTs 33 a to 33 c are sent to the line memory 63.

A matrix circuit 35 is provided at a stage subsequent to the LUTs 34a to 34c.
An OM 36 and an average value calculation circuit 37, and a ROM 67 and an average value calculation circuit 68 are provided. The signal passed through the average value calculation circuit 37 is transferred to the ROM 36, and the average value calculation circuit 68
The signal passed through is transferred to the ROM 67.

In the ROM 36, data conversion is performed from one dye amount and its average value to an enhancement coefficient, and in RO6M37, data conversion is performed from another dye amount and its average value to an enhancement coefficient. The signals passed through the ROMs 36 and 67 are subjected to conversion of the degree of emphasis by the data of the weighting coefficients WD and WD 'sent from the switches Sa to Sd and Sa' to Sd 'of the selection switches 62A and 62B on the front panel. Are sent to the ROMs 38 and 69 respectively.

A ROM 39 provided after the ROM 38
Signal lines sent from the LUTs 33a to 33c are connected to a to 39c via a timing adjustment line memory 63.

The ROMs 39a to 39c are followed by R
ROM7 that performs data conversion based on the signal from OM69
0a to 70c are connected. D / A converters 42 a to 42 c are connected to the subsequent stage, and are connected to the monitor 4 and the image filing device 5. Next, the operation of the present embodiment will be described.

The signals sent by the video processor 3 are converted into digital signals by A / D converters 32a to 32c. The RGB signals converted to digital signals are subjected to inverse γ correction conversion by LUTs 33a to 33c,
The data is sent to the line memory 63 and the LUTs 34a to 34c.

The LUTs 34a to 34c perform logarithmic conversion in the hemoglobin calculation processing of the first embodiment. After each of the RGB signals is logarithmically converted, the matrix circuit 35 performs data conversion corresponding to (1) of the first embodiment to calculate the hemoglobin amount IHb.

The matrix circuit 35 can also calculate the amount of pigment other than hemoglobin. These dye amounts are sent to the ROMs 36 and 67, respectively, and sent to the average value calculation circuits 37 and 38, respectively. The average value calculation circuits 37 and 68 perform the same processing as the average value calculation circuit 37 of the third embodiment, and send the calculated data to the ROMs 36 and 67, respectively.

The ROMs 36 and 67 store the RO of the third embodiment.
Similarly to M36, data is converted from the dye amount and the average value of the dye amounts in the image into an enhancement coefficient. This emphasis coefficient is stored in ROM3
8, 69, and can be converted into further enhanced emphasis coefficients by the data of the weighting coefficients WD and WD 'set on the front panel or the like.

The emphasis coefficient data converted by the ROM 38 is sent to the ROMs 39a to 39c, and corresponds to the emphasis image creation processing of the first embodiment based on the RGB signal and the signal from the ROM 38 whose timing has been adjusted by the line memory 63. Data conversion is performed, and γ correction processing is performed.

An image enhanced based on one dye amount is obtained from the ROMs 39a to 39c. After this, RO
In M70a to 70c, based on the amount of another dye data converted by the ROM 69, the ROM 39a to
Enhancement processing conversion is performed in the same manner as 39c.

Next, after being converted into analog signals by the D / A converters 42a to 42c, the signals are transferred to the monitor 4 or the image filing device 5, where the image is displayed and recorded. In this embodiment, data conversion is performed using a ROM or a matrix circuit, but an FPGA or the like may be used as in the third embodiment and its modifications.

According to the present embodiment, even when a plurality of dyes are present, the enhancement processing is performed separately for each of the dyes.
For example, defects such as a change in the color of a dye or the like are reduced. In addition, it is possible to effectively emphasize each dye.

FIG. 16 is a block diagram showing the structure of an image enhancement unit 61 according to a modification of the fourth embodiment. The endoscope apparatus of this modification has the same configuration as that of the third embodiment, and the internal configuration of the image enhancement unit 61 is slightly different from that of the image enhancement unit 61 shown in FIG.

As shown in FIG. 16, the image enhancement unit 6
The configuration in 1 is different only in the ROM 71 for performing the reflection correction conversion provided in the subsequent stage of the matrix circuit 35 and the reference value determination circuit 72 provided in the preceding stage of the ROM 36 for determining the enhancement coefficient from the amount of hemoglobin. I have. The reference value determination circuit 72 determines a reference value based on data input from the keyboard 62C, for example. Note that the controller 40 is omitted in FIG. 16 for simplification.

Next, the operation of the present embodiment will be described.
ROM 71 provided at the subsequent stage of matrix circuit 35
Then, in order to further increase the accuracy of the calculated amount of hemoglobin, correction conversion is performed by a reflection system such as an endoscope.
The endoscope illuminates a site to be inspected, such as a diseased part, with the illumination light transmitted by the light guide 18, and captures the illumination light reflected at the site to be inspected as an object image via the objective lens 17.

In this case, even if the intensity distribution of the illuminating light emitted from the light source device 3A has no wavelength dependence due to, for example, the transmission characteristics of the light guide 18 with respect to the wavelength, the light is actually emitted from the end of the light guide 18. Since the intensity distribution changes, the accuracy of the calculated amount of hemoglobin can be increased by performing correction in consideration of the influence.

The corrected and converted IHb is sent to the ROM 36. In the reference value determination circuit 72, the IH is input based on data input from the keyboard 62C on the front panel.
A reference value for enhancing b is selected.

The reference value determined here is sent to the ROM 36, and based on the value of IHb sent from the ROM 71, the emphasis coefficient is determined in the same manner as in the third embodiment, and sent to the ROM 38 at the subsequent stage. . The processing in the circuits after the ROM 38 is the same as in the third embodiment. According to the present embodiment,
Even in a reflection system such as an endoscope apparatus, the amount of hemoglobin is calculated with high accuracy, so that a more accurate enhancement process is performed.

FIG. 17 shows the structure of the image enhancement unit 61 according to the fifth embodiment of the present invention. FIG. 13 is a block diagram, and FIG. 13 is a conversion graph of the enhancement coefficient conversion table.

The endoscope apparatus of this embodiment is the same as that of the third embodiment, except that the internal configuration of the image enhancement unit 61 is different. As shown in FIG. 17, the configuration within the image enhancement unit 61 is such that an enhancement coefficient conversion table 73 is provided at the subsequent stage of the ROM 38, and the range correction tables 74a, 74b, and 74 are provided at the subsequent stage of the ROMs 39a, 39b, and 39c.
c is provided.

The other structure is the same as that of the third embodiment shown in FIG. Next, the operation of the present embodiment will be described.
The emphasis coefficient converted by the ROM 38 is used in the emphasis coefficient conversion table 73 by, for example, a conversion function as shown in FIG.
Make sure that the emphasis coefficient does not exceed a certain value.

Further, the present invention is not limited to the conversion function shown in FIG. 18, and for example, a conversion function in which all values equal to or less than 0 become 0 may be used. ROMs 39a, 39b, 39c
Are converted to 0 or 255 in the range correction tables 74a, 74b, and 74c with respect to those deviating from values of 0 to 255 in the range correction tables 74a, 74b, and 74c.

According to this embodiment, even when the emphasis coefficient is set to be large, it is possible to reduce the overexposure of a white portion having a small amount of hemoglobin. Other functions and effects are the same as in the third embodiment.

Further, the present invention is not limited to the above embodiments,
For example, an image illuminated by a narrow-band filter may be processed, in which case, as generally known, R
For (i, j), image illuminated at 805 nm, G
For (i, j), an image illuminated at 580 nm may be used, and a more accurate enhanced image can be obtained.

The narrow band filter is set to 650 nm, 80
5 nm, 900 nm or 569 nm, 577 nm,
By using a material that transmits light having a wavelength of 586 nm, it is possible to perform a predetermined calculation in the matrix circuit 25 and obtain information on hemoglobin oxygen saturation. It is also possible to perform an emphasis process based on the information on the hemoglobin oxygen saturation.

Further, in the above embodiment, the emphasis is performed based on the average value of hemoglobin in one screen. However, the emphasis may be performed by flattening a histogram. Further, in the present embodiment, the frame sequential endoscope has been described. However, the same processing may be performed in the simultaneous endoscope after converting the obtained image into an RGB image.

Further, the present invention is not limited to an electronic endoscope having a solid-state image pickup device at the distal end of the insertion portion, but may be replaced with an eyepiece of an endoscope such as a fiberscope or a rigid endoscope capable of observing the naked eye, or replaced with an eyepiece. In addition, the present invention can be applied to an endoscope that is connected to an external television camera having a solid-state imaging device such as a CCD.

As described above, according to the first to fifth embodiments, since the emphasis processing can be performed based on the biological function information, that is, the information of the hemoglobin pigment concentration distribution which is dominant in the color of the endoscope image, the blood processing can be performed. It is possible to effectively and naturally emphasize a part where the flow state is delicately changed, so that the diagnostic performance is further improved. In addition, effective enhancement can be performed on dyes and the like, and when both dyes are present, enhancement can be performed on each of them.

Next, a sixth embodiment of the present invention will be described. The endoscope apparatus of the sixth embodiment has the same configuration as that shown in FIG. 12, but differs in the internal configuration of the image enhancement unit 61. FIG.
Shows the configuration of the image enhancement unit 61.

RGB output from video processor 3
The signal is input to the A / D converter 114, and is converted from an analog signal to a digital signal. The output RGB signals of the video processor 3 have been subjected to γ correction processing, which is a non-linear characteristic, because the input / output characteristics of the monitor are not flat.

As a result, a problem occurs when performing an operation such as a calculation of the amount of a dye. In order to cancel this correction, the correction signal is input to an inverse γ correction circuit 115 composed of a ROM or the like and converted into a linear RGB signal. Is done. The converted RGB signals are supplied to a frame memory 116, a region-of-interest detection circuit 11 for detecting a region of interest as a region of interest to the operator.
7. Dye amount calculation circuit (IHb calculation circuit in this embodiment)
118, respectively.

RG input to region of interest detection circuit 117
The B signal is different from normal mucous membrane during observation, such as a dark part such as a lumen part where reflected light does not return, or a halation part where the reflected light amount is too large to be taken properly due to the signal level, and is not suitable for IHb calculation. An appropriate portion is detected, and an identification signal of a normal portion or an abnormal portion is output to the average value calculation circuit 119. The configuration of the region of interest detection circuit 117 is, for example, a window type comparator 117a, 117.
b, 117c and an OR gate 118d.

It is to be noted that E1 and E2 connected to the input terminal of the comparator 117c determine the level for extracting the region of interest, and the level Eb of the B signal input through the inverse γ correction circuit 115 is E1>Eb> If the condition of E2 is satisfied (that is, Eb ≧ E1 or E2 ≧ Eb), the region is determined to be a region of interest. If this condition is not satisfied, the region is regarded as not a region of interest and is not used for calculation such as calculation of an average value.

RGB input to IHb calculation circuit 118
The signal is logarithmically converted by a ROM or the like, an operation is performed between the R, G, and B signals, and a value correlated with IHb is calculated. For example, when calculating the amount of pigment (IHb) correlated with hemoglobin contained in blood, it can be calculated by using the following equation.

Hemoglobin content (IHb) = C · LogR
/ G (C is a coefficient) The configuration of the IHb calculation circuit 118 is not limited to the configuration using the ROM and the subtractor, and an IC or the like that can perform a matrix operation may be used. Note that the calculated value correlated with the amount of IHb dye is output to the average value calculation circuit 119 in the subsequent stage.

The average value calculating circuit 119 is composed of a cumulative adder and a divider. Only the IHb in the pixel of the normal part determined by the region of interest detecting circuit 117 is added by the cumulative adder, and one image is obtained. When the cumulative addition of the minute is completed, the division is performed by the number of times of the cumulative addition.

That is, the average value of IHb only at the normal part is determined. By emphasizing the average value as a center, it is possible to effectively emphasize a portion where the amount of hemoglobin slightly changes (redness, fading, etc.) as compared with the normal mucosal color. Note that the configuration of the average value calculation circuit 119 may be realized using a programmable gate array or the like.

The average value of the calculated amount of dye in the region of interest and I
Hb is input to the ROM 120 functioning as an IHb enhancement circuit. Then, by inputting a variably set emphasis level which is set by a combination of ON / OFF of the emphasis level setting switch 113 of the front panel 112, the RGB image is converted into an emphasis IHb.

The converted emphasis IHb is stored in the frame memory 1
Along with the 16 RGB images, they are outputted to ROMs 121a, 121b and 121c for generating an emphasized image to be converted into an emphasized image. The amount of IHb dye emphasized in the ROM 120 is calculated by, for example, the following formula.

Enhancement IHb = K · (IHb−average value) + average value (15) (where K is an enhancement level set by the switch 113)
In the ROMs 121a to 121c, the emphasized IHb and R, G, B
Is converted into an enhanced RGB image in which IHb is enhanced. For example, the enhanced R image in the enhanced RGB image is converted by the following equation.

R ′ = R · 10 {αr · (IHb−emphasized IHb)} (16) (where αr is a constant determined by the type and wavelength of the dye) (16) By substituting the equation and rewriting, R ′ = R · 10 {αr · (1−K) · (IHb−average)} (16 ′) As can be seen from the equation (16 ′), the enhanced R image Is an exponentially enhanced RH image from the average value of IHb with respect to the unenhanced R image. Other G and B images have similar characteristics.

The emphasized RGB image signal is converted to a γ correction circuit 122
, And is subjected to γ correction canceled by the inverse γ correction circuit 115, and is output to the D / A converter 123. D / A
The converter 123 converts the digital signal into an analog signal and outputs an enhanced image. According to the present embodiment, it is possible to effectively emphasize redness and fading, which are delicately changing compared to the normal mucous membrane, and this is advantageous in improving diagnostic performance.

FIG. 20 is a block diagram showing the internal configuration of the image enhancement unit 61 according to the seventh embodiment of the present invention.

The endoscope apparatus of this embodiment is the same as the endoscope apparatus 60 of the third embodiment shown in FIG. 12, except for the internal configuration of the image enhancement unit 61. As shown in FIG. 20, the region of interest detection circuit 117 in the image enhancement unit 61 of the sixth embodiment is not provided, and the average value calculation circuit 1
A histogram calculation circuit 124 is provided instead of 19.

IH output from IHb calculation circuit 118
The value correlated with the amount of dye b is input to the subsequent histogram calculation circuit 124. Histogram calculation circuit 124
Is composed of a histogram calculation IC or CPU, calculates a histogram of the IHb dye amount for one image, and outputs the most frequent and most frequent dye amount data in the ROM 120 at the subsequent stage. . In the ROM 120, the emphasis dye amount is calculated by the following equation, and is output together with IHb to the subsequent ROMs 121a to 121c.

Enhancement IHb = K · (IHb−most value IHb
(Data) + most-valued IHb data (K is the emphasis level) Other configurations and operations are the same as in the sixth embodiment. According to the present embodiment, it is possible to obtain the same effects as in the sixth embodiment.

FIG. 21 shows the internal structure of the image enhancement unit 61 according to the eighth embodiment of the present invention. The endoscope device of the present embodiment is the same as the endoscope device of the third embodiment,
The internal configuration of the image enhancement unit 61 is different. As shown in FIG. 21, a histogram processing circuit 125 is provided instead of the histogram calculation circuit 124 in the image enhancement unit 61 of the seventh embodiment, and the ROM 120 is removed.

The histogram processing circuit 125 calculates a histogram for one image of the IHb dye amount input from the preceding stage, and enlarges the histogram centering on the most frequent dye amount.

That is, when the histogram as shown in FIG. 22A is calculated, for example, a
The process of expanding and converting the value of IHb located at the position displaced by the value of (a) from the maximum value to the position displaced by the value of ka as shown in FIG.
Is k> 1).

Further, the image may be enlarged centering on the average value of IHb in one image, or may be enlarged centering on a fixed value. In addition, without expanding the histogram,
A process of moving the whole to a higher value or a lower value while maintaining the shape of the histogram may be performed.

After the histogram processing is performed in this manner, the second ROMs 121a to 121c store the second
The same processing as in the embodiment is performed. In addition, other configurations,
The operation and effects are the same as in the seventh embodiment.

[0165] Figure 23 shows an internal configuration of an image enhancement unit 61 in the ninth embodiment of the present invention. The endoscope apparatus of the present embodiment is the same as the endoscope apparatus 60 of the third embodiment, except for the internal configuration of the image enhancement unit 61. As shown in FIG. 23, instead of the histogram processing circuit 125 in the image enhancement unit 61 of the eighth embodiment, an enhancement processing unit 126
Is provided.

The emphasis processing section 126 performs an emphasis process using a CPU or the like according to the procedure shown in FIG. Further, it has a weighting function generation circuit 126a that generates a weighting function W (t) described later, and the weighting function W (t) is determined by a parameter PD input from the keyboard unit 111 of the front panel 112.

The IHb pigment amount input by the preceding IHb calculation circuit 118 is compared with the IHb dye amount in step S31 in FIG.
Perform a two-dimensional discrete Fourier transform at
(T) and an imaginary term Ai (t). Next, the filtering in step S32, that is, step S32
The real term Ar (t) and the imaginary term Ai (t) of the data generated by the two-dimensional discrete Fourier transform at 31
Is multiplied by a weighting function W (t) described later,
A real term Br (t) and an imaginary term Bi (t) of the dye amount data of IHb after emphasis are generated.

After this filtering is completed, in step S33, the inverse transform of the two-dimensional discrete Fourier transform in step S31, that is, the two-dimensional discrete Fourier inverse transform is performed, and the IHb dye amount data resulting from the enhancement processing is obtained. IHb dye amount generated and enhanced and IHb before enhancement
Is output to the ROMs 121a to 121c at the subsequent stage and is converted into an enhanced RGB image.

The process of creating the weighting function W (t) used for the above filtering is performed as follows. In the so-called optical Fourier transform, a DC component that determines the overall density value of an image is located at the center on a spatial frequency plane, and a low-frequency component in terms of spatial frequency exists near the DC component.

The filter to be created is such that a point apart from the center by a certain distance is set as the highest point of emphasis, and the point is used as a boundary to reduce the value of the weight for the low frequency component and the high frequency component. Various types of weighting functions having such properties are conceivable, and the following filter is one example.

Let the coordinates of the center O of the spatial frequency plane be (u0,
v0), assuming that the coordinates of the target point P on the same plane are (u, v), the square tt of the distance t of the OP is tt = ｛(u-u0). (u-u0) + ( v−u0) · (u−u0)｝ (17) If the weighting value is W, W is t
As a function W (t), whose value is 0 ≦ W
(T) ≦ α is satisfied. Here, α is the maximum value of the weight.

The filter created here is 0 ≦ t ≦ p / 2 and p / 2 ≦ t, where p is the diameter of a circle consisting of a set of points giving the maximum value of W (t) with 0 as the center. Consists of separate functions for each case of 0 ≦ t
A cos function is used for ≤p / 2, and a normal distribution function is used for p / 2≤t.

In the cos function part of the filter to be created, its amplitude is A. The cos function part is continuous with the normal distribution function part at t = p / 2, and W (p / 2) = α
It is assumed that Also, the minimum value must be taken at t = 0. Equation (18) is obtained as a function satisfying these conditions.

W (t) = α−A−A · cos (t · π / (p · 2)) (18) The function of equation (18) is the maximum value α, t at t = p / 2 = 0
(Center in the spatial frequency domain) minimum value α-2 · A
Take.

On the other hand, the normal distribution function takes the maximum value α at t = p / 2 and is connected to the cos function. If the standard deviation is σ in such a function, equation (19) is obtained. W (t) = α · exp (−0.5 · ((t · (p / 2)) / (σ · σ)) (19) where p / 2 ≦ t.

In the equation (19), σ is given by σ = (CTR− (p · 2)) / r (CTR: x coordinate value of center, r: real number). When p = 0, only equation (19) is applied.

In the equations (18) and (19), α, A, p
And r as parameters, it is possible to obtain filters with different degrees of enhancement. FIG. 25 is an example of the shape of the filter created under the above conditions, and α =
4, A = 1.5, p = 60, r = 4.
When applied to an infrared light image using ICG, for example, α = 4, A = 1.5, p = 12, and r = 3 may be given.

By performing a filtering process for emphasizing a low-frequency region in the spatial frequency region using the above-described filter, a high-frequency component which is a noise in a dye amount distribution image can be reduced or suppressed. The driving state and the like can be made clearer, and an emphasized image that can be easily diagnosed can be obtained. Therefore, when diagnosing with an endoscope image, it becomes a very useful image processing means.

The processing unit of the two-dimensional discrete Fourier transform, filtering, and two-dimensional discrete Fourier inverse transform in the embodiment described above can also be realized as a mask operation by convolution.

According to the present embodiment, the same effect as that of the sixth embodiment can be obtained, and by changing the value of each parameter,
It is possible to enhance various frequency components of the dye amount distribution image.

Next, a tenth embodiment of the present invention will be described. In this embodiment, an ICG (Indo-cyanine green) density distribution is calculated, and an endoscopic image in which the ICG density distribution is emphasized can be obtained.

The endoscope device 8 of the tenth embodiment shown in FIG.
Reference numeral 1 denotes an electronic endoscope 2, a video processor 83 connected to the electronic endoscope 2, a monitor 4 connected to the video processor 83 for displaying an endoscope image, and a connection to the video processor 83. The image processing device 84 includes an image processing device 84 that performs image processing, and a second monitor 85 that is connected to the image processing device 84 and that displays an image-processed endoscope image. Further, an ICG solution 79 is injected into a vein of a living body by a syringe 78 so that an image emphasized by the amount of ICG dye can be obtained.

The electronic endoscope 2 is the same as that described in the first embodiment. FIG. 27 shows the configuration of the video processor 83. The video processor 83 includes a light source device 83A
And a signal processing circuit 83B. This signal processing circuit 83B has the same configuration as the signal processing circuit 3B in FIG. 2 without the switch SW1. In FIG. 2, the light source device 83A has a filter turret 80 disposed on an optical path between the lamp 19 and the rotary filter 21.

The rotary filter 2 in this embodiment
R, G, B transmission filters 21a ', 2 attached to
1b 'and 21c' have transmission characteristics as shown in FIG. That is, the G and B color transmission filters 21b 'and 21c'
In addition to the conventional transmission characteristics in the G and B wavelength ranges, those having transmission characteristics in the infrared region as shown by solid lines and broken lines are used.

As shown in FIG. 29, the filter turret 80 has two windows formed symmetrically from the center of the light-shielding disk, and includes a first wavelength limiting filter 86a and a second wavelength limiting filter 86b. Is attached to each.
The center of the filter turret 80 is, for example, the motor 8
7 is attached to the rotating shaft, and the foot switch 88 is turned ON.
Then, the filter turret 80 is rotated by 180 °,
The filter arranged on the optical path can be switched.

The first wavelength limiting filter 86a and the second wavelength limiting filter 86b have transmission characteristics as shown in FIG. In other words, the first wavelength limiting filter 86a has a transmission characteristic in the visible region, while the second wavelength limiting filter 86b has a wavelength range slightly shorter than 800 nm to 900 nm.
Transmits light in a slightly longer wavelength range.

Therefore, as shown in FIG. 27, when the first wavelength limiting filter 86a is set on the optical path, only light in the visible region passes through the filter 86a,
1, the light is separated into R, G, and B illumination lights as shown in FIG. With this illumination light, normal observation with illumination light in the visible region is possible.

On the other hand, when the second wavelength limiting filter 86b is inserted on the optical path, only light in the infrared region passes through the filter 86b, and is
805 nm narrow-band wavelength light and 900 nm narrow-band wavelength light are radiated in time series. With this illumination light, special light observation with illumination light in the infrared region is possible.

FIG. 33 is a block diagram showing the structure of the image processing device 84. R, G, and B as video signals output from the video processor 83 are output to an A / D converter 92.
And converted from an analog signal to a digital signal. Next, the signal is input to the inverse γ correction circuit 93 to cancel the γ correction. The output of the inverse γ correction circuit 93 is input to a frame memory 94 and an ICG density calculation circuit 95.

The ICG density calculating circuit 95 calculates the ICG density index = C * LogG /
Calculate R or C * LogB / R (C is a coefficient). The configuration is shown in FIG. The infrared R, G, and B signals are stored in logarithmic conversion ROMs 101r, 101g,
1b and logarithmically converted.

The logarithmically converted G and B signals are supplied to the selector 1
02, one of the signals is selected by the select signal SS from the CPU 98. The selected signal and the R signal are input to the subtractor 103, where the signal is LogG / R or LogG / R.
B / R is calculated. Thereafter, the multiplier 104
U98 is multiplied by the signal of coefficient c to calculate the ICG density index.

The calculated ICG concentration index is represented by R in FIG.
Input to OM96. The ICG density calculation circuit 95
Is not limited to the above configuration, and may be realized by a matrix circuit with a built-in ROM. Foot switch 9
Reference numeral 7 is connected to a CPU 98 in the image processing apparatus 84. When the foot switch 97 is pressed, the CPU 98 determines the number of presses, the degree of emphasis based on the pressed button, and the like, and transfers it to the ROM 96.

In the ROM 96, the emphasis coefficient is determined based on signals from the CPU 98 and the ICG density calculation circuit 95,
The data is transferred to the ROMs 99r, 99g, and 99b. ROM99
At r, 99g, and 99b, an enhanced image is output from the output from the frame memory 94 and the enhancement coefficient determined by the ROM 96. The enhanced image converted by the ROM 99 is subjected to a predetermined γ correction by the γ correction circuit 90,
After being input to the A-converter 91 and converted from a digital signal to an analog signal, it is displayed on a monitor 85 or the like.

Next, the operation of the present embodiment will be described.
The light from the ultraviolet to the infrared emitted from the lamp 19 passes through the first wavelength limiting filter 86a or the second wavelength limiting filter 86b of the filter turret 80 having the configuration shown in FIG. The light enters a rotary filter 21 rotated by 20.

When the first wavelength limiting filter 86a is inserted on the optical path, only light in the visible region passes through the filter 86a, and the rotating filter 21 emits R, G, B illumination light as shown in FIG. And irradiated in chronological order. With this illumination light, normal observation with illumination light in the visible region is possible.

When the second wavelength limiting filter 86b is inserted into the optical path by turning on the foot switch 88, only light in the infrared region passes through the filter 86b,
805 as shown in FIG.
A narrow-band wavelength light of nm and a narrow-band wavelength light of 900 nm are irradiated in time series. With this illumination light, special light observation with illumination light in the infrared region is possible.

The switching of these wavelength limiting filters is as follows.
The present invention is not limited to the foot switch 88, and may be provided by providing a changeover switch on a front panel of the video processor 83 or the like.

As described above, the first wavelength limiting filter 86
In the state where a or the second wavelength limiting filter 86b is inserted on the optical path, the irradiation light separated by the group of color transmission filters of the rotary filter 21 is guided into the body cavity via the light guide 18 and distributed. The light is emitted as illumination light into the body cavity via the lens 16. A subject image by each illumination light is formed on the CCD 23 by the objective optical system 17 and is converted into an electric signal. The output signal of the CCD 23 is supplied to an amplifier 24.
And is converted to a predetermined γ characteristic by the γ correction circuit 25.

The output of the gamma correction circuit 25 is converted into a digital signal by an A / D converter 26,
, And are decomposed into respective wavelengths in a time series, and stored in the memories 28r, 28g, 28b as images. That is, the selector 27 switches the output in synchronization with the rotation of the rotary filter 21. The video signals read from the memories 28r, 28g, 28b are synchronized, converted into analog video signals by the D / A converters 29r, 29g, 29b, and output as R, G, B color signals.

The second wavelength limiting filter 86b
Is inserted into the optical path, special observation becomes possible.
805 nm wavelength light and 900 nm wavelength light as shown in FIG. When ICG is injected intravenously into a living body using a syringe 78 or the like, as shown in FIG. 35, ICG has a strong absorption characteristic near 805 nm. It is displayed darker than the mucous membrane.

When light of 900 nm is irradiated, ICG does not absorb much near this wavelength.
No change appears in the image when CG is injected intravenously. ICG
In the density calculation circuit 95, by performing an inter-image operation between the image irradiated at 900 nm and the image irradiated at 805 nm, an image correlated with the ICG density excluding the influence of the irradiation light amount is obtained.

In order to perform an emphasis process on the image correlated with the ICG density, the CPU 98 determines an emphasis level to what extent emphasis is performed from a signal generated by pressing the foot switch 97. The foot switch 97 may have any shape, a plurality of switches may be provided, the switches may be divided according to the emphasis level, or one switch may be used, and the emphasis level may change each time the switch is pressed.

With the emphasis level determined by the CPU 98, emphasis processing is performed on an image correlated with the ICG density, and the ICG density at each pixel is changed in a pseudo manner. From the pseudo-determined ICG density distribution, ROMs 99r, 99
In steps g and 99b, the signal of the original image is converted from the signal of the ICG density distribution image into an enhanced image. The converted enhanced image is subjected to predetermined γ correction by the γ correction circuit 90,
The digital signals are converted into analog color signals R ', G', B 'by the / A converter 91 and displayed on the monitor 85. FIG. 36 shows the processing content for displaying an image emphasized by the ICG density in this embodiment.

First, as shown in step S41, IGC is injected (administered) into the living body, and in the next step S42,
By operating the foot switch 88, the second wavelength limiting filter 86b is arranged on the optical path to be in an illumination state by infrared light.

In this illumination state with infrared light, the infrared RGB signals captured as shown in step S43 are input to the image processing device 84. After the A / D conversion, inverse gamma correction is performed as shown in step S44.
Further, in the next step S45, the ICG density is calculated by the ICG density calculation circuit 95.

The I calculated as shown in step S46
The CG density is emphasized by the ROM 96 according to the input data of the foot switch 97 and the like. Next, step S47 is performed by the ROMs 99r, 99g, and 99b.
Is performed to convert the image into an RGB image having an enhanced ICG density (of course, a pseudo RGB image), and γ correction is performed in step S48.
As shown in step S49, the emphasized image emphasized is displayed on the monitor 85 in pseudo color.

It is to be noted that, instead of step S47 in FIG. 36, the image is converted to a monochrome image as shown in step S47 'indicated by a dotted line, and further subjected to γ correction (step S48) to display the emphasized image emphasized by ICG in the monochrome image. (Step S49 '). According to the present embodiment, the obtained enhanced image is an image in which the density of ICG is changed in a pseudo manner, so that an image that does not seem unnatural is obtained. In addition, 900 which is not affected by ICG concentration
By normalizing the image obtained with the 805 nm irradiation light by the image obtained with the illumination light of nm, the distinction between the dark part and the part with high ICG density becomes clear due to the difference in the amount of illumination light. Diagnostic ability such as is improved.

Further, by observing the ICG concentration after the intravenous injection of ICG in a time-series manner, the hemodynamics can be diagnosed in real time. Note that the present embodiment is not limited to the above configuration. For example, when an image signal is transferred from the video processor 83 to the image processing device 84, a digital signal may be used instead of an analog signal.

[0209] Instead of performing the emphasis processing on the original image, a monochrome image in which the ICG density distribution is emphasized or an image on which the pseudo color processing has been performed may be displayed. Also, instead of displaying the emphasized image on the monitor 85, the monitor 4 is connected via the image processing device 84, and a selector or the like that switches the normal visible observation in synchronization with the switching of the special light observation is provided in the image processing device 84. The output of the video processor 83 may be directly displayed on the monitor 4 during normal visible observation, and the image processing may be performed in the image processing device 84 and displayed on the monitor 4 during special light observation.

Further, the calculated ICG density distribution image may be subjected to band emphasis processing to emphasize minute ICG density changes. In this embodiment, the emphasis level is switched using the foot switch 97. However, the emphasis level may be switched by providing a switch on the front panel of the video processor 83 or the like. Switching between visible observation, special light observation, and enhancement coefficient may be performed.

Further, the video processor 83 and the image processing device 84 may be housed in one housing. Also, ICG
Calculation such as calculation of the density and determination of the emphasis coefficient may be performed by a CPU or the like.

FIG. 34a shows infrared light of two wavelengths (R is 805n).
(m, G, and B are 900 nm). The configuration in the case of calculating the ICG density index excluding the influence of the illumination light amount is shown.
FIG. 34B shows a configuration in the case where the ICG concentration index is calculated using a single wavelength (all of R, G, and B are 805 nm). R,
The signals input by G and B are input to a luminance calculation matrix circuit 105 for calculating a luminance signal Y, and Y = 0.3R +
After the calculation of 0.6G + 0.1B is performed, the luminance signal Y is input to the ROM 106, and is converted so as to be Log 255 / Y to calculate the ICG density index.

In the case of this configuration, since the influence of the amount of illumination is affected, the configuration of FIG. 34A is more suitable for calculating the ICG density index with higher accuracy.

FIG. 37 shows an endoscope apparatus 131 according to the eleventh embodiment of the present invention. In the tenth embodiment, the video processor 8
3 and the image processing device 84 are separate units, but in this embodiment, the image processing unit 132 (see FIG. 38) is built in the video processor 133. The electronic endoscope 2 'in this embodiment is different from the electronic endoscope 2 in the tenth embodiment in that a color separation filter array 13 is provided on the front surface of the CCD 23.
4 (see FIG. 38) is attached. In this embodiment, the same function as that of the tenth embodiment is realized by the simultaneous electronic endoscope 2 '.

FIG. 38 shows the internal structure of the video processor 133. The video processor 133 includes a light source device 133A that outputs illumination light, a signal processing circuit 133B that performs signal processing for generating a standard video signal, and an image processing unit 132 that performs image processing.

In the light source device 133A, a filter turret 80 which can be rotated by 180 ° by a motor 87 is disposed in front of a lamp 19 which emits light by a power source 136. The two windows of the filter turret 80 have a first wavelength limiting filter 86a having a characteristic as shown in FIG.
And a wavelength limiting filter 86b. The first wavelength limiting filter 86a and the second wavelength limiting filter 86b have characteristics similar to those of the tenth embodiment (see FIG. 30).

The rotation of the motor 87 for rotating the filter turret is controlled by the motor driver 140. The motor driver 140 can arrange one of the filters 86a and 86b on the optical path by operating, for example, a selection switch 142 of the front panel 141.

For example, each time the selection switch 142 is turned ON once, the filter turret 80 is rotated by 180 °. For example, in the state of FIG.
When N, the filter turret 80 is rotated by 180 °, and the filter 86b is arranged on the optical path.

The illumination light that has passed through the filter of the filter turret 80 is incident on the incident end of the light guide 18, is guided to the exit end face of the distal end portion 12 via the light guide 18, exits from the exit end face, and exits from the observation site. Is to be illuminated. The optical image of the subject illuminated by the illumination light is formed on the imaging surface of the CCD 23 by the objective lens system 17.

At this time, color separation is performed by the color separation filter array 134. This color separation filter array 134
As shown in FIG. 39, three color transmission filters of G (green), Cy (cyan) and Ye (yellow) are arranged in a mosaic pattern. FIG. 40 shows the transmission characteristics of the G, Cy, and Ye filters.

The CCD 23 is read out by applying a drive signal from a driver 147 constituting a signal processing circuit 133B in the video processor 133, and is read out by an amplifier 148.
After amplification in LPF149, 150 and BPF15
One is passed.

The LPFs 149 and 150 are, for example, 3 MHz
, 0.8 MHz, and a signal passed through each of them is divided into a high-frequency luminance signal YH and a low-frequency luminance signal YL.
2, 153, and γ correction and the like are performed.

The luminance signal YH on the high frequency side which has passed through the process circuit 152 is subjected to horizontal contour correction, horizontal aperture correction, and the like by the horizontal correction circuit 154, and then to the color encoder 1
55 is input. The low-frequency side luminance signal YL passed through the process circuit 153 is input to a video display matrix circuit 156, where tracking correction is performed.

On the other hand, the read signal of the CCD 23 is:
A color signal component is extracted by passing through a BPF 151 having a pass band of 58 ± 0.5 MHz.
L (1H delay line) 157, adder 158 and subtractor 159 are input to separate and extract color signal components B and R.

In this case, the output of 1HDL 157 is
The processing is performed by the process circuit 153, and the vertical correction circuit 1
The luminance signal YL on the low frequency side which has been subjected to the vertical aperture correction at 60 is mixed with the mixer 161 and the mixed output is added to the adder 15
8 and a subtractor 159.

The color signal B of the adder 158 and the color signal R of the subtractor 159 are respectively
163, and γ-corrected using the low-frequency side luminance signal YL passed through the correction circuit 164. Further, the γ-corrected color signals B and R are input to demodulators 165 and 166, respectively, converted into demodulated color signals B and R, and then input to a matrix circuit 156.

The matrix circuit 156 generates chrominance signals RY and BY, which are then input to the color encoder 155, where the luminance signal obtained by mixing the luminance signals YL and YH and the chrominance signals RY and B are output. A chroma signal obtained by quadrature-modulating −Y with a subcarrier is mixed, and a synchronizing signal is superimposed thereon, and a composite video signal is output from an NTSC output terminal. The YL, R, and B signals output from the preceding stage of the matrix circuit 156 are output to the RGB generation matrix circuit 14.
After being converted into RGB signals in step 3, the image signals are input to the image processing unit 132.

The driver 147 receives a synchronization signal from the synchronization signal generation circuit 168, and
7 outputs to the CCD 23 a drive signal synchronized with the synchronization signal. Further, the video composite signal is transmitted to the color monitor 4.
Thus, the observation site is displayed in color.

On the other hand, the configuration of the image processing unit 132 is
This is the same as the embodiment. Next, the operation of the present embodiment will be described. At the time of normal visible observation, a first wavelength limiting filter 86a is inserted on the optical path as shown in FIG.
The filter 86a limits the wavelength range of the illumination light to the visible range. Accordingly, the subject is illuminated with illumination light having a wavelength band in the visible region as shown in FIG. 41, and a normal visible observation image is obtained.

On the other hand, when performing special light observation using infrared light, by turning on the selection switch 142, the filter turret 80 is rotated by 180 °, and the second wavelength limiting filter 86b is inserted in the optical path. Illumination light in the infrared wavelength band as shown in FIG. 42 is applied.

Note that the Ye filter has a wavelength of 800 nm to 900 nm.
, And the G filter has the characteristic of transmitting the light from the vicinity of 890 nm to the long wavelength side.

The image obtained by this illumination light is an ICG
Before intravenous injection, in the range of 805 nm and 900 nm,
Because there is almost no change in changes such as blood volume,
It becomes whitish image. However, since only the illumination light near 805 nm is strongly absorbed by intravenous injection of ICG,
The signal transmitted through the G and Cy filters does not change, and only the signal transmitted through the Ye filter is greatly reduced. That is, IC
Variations in G density are represented by red variations. Therefore, IC
An image is obtained in which the blood vessel portion including G appears to appear in cyan.

Even if the infrared observation is performed as it is, it is possible to observe the running state of the blood vessel sufficiently.
In order to enable observation even at the density, the image processing unit 132 creates an enhanced image.

The configuration of the image processing unit 132 is the same as that of the tenth embodiment as described above, but the ICG shown in FIG.
By calculating G / R or B / R in the density calculation circuit 95, it is possible to calculate a value correlated with the ICG density which does not receive a change in the illumination light amount. The following processing is the same as in the tenth embodiment.

According to the present embodiment, since an enhanced image capable of sufficiently grasping the running state of the blood vessel can be obtained without intravenous injection of a large amount of ICG, the mental effect on the patient can be reduced. In addition, the ability to diagnose a lesion or the like is improved.

Note that, like the tenth embodiment, this embodiment is not limited to the above method.

Next, a twelfth embodiment of the present invention will be described. The endoscope apparatus of the present embodiment uses a video processor 173 which is different from the video processor 83 of the endoscope apparatus 81 of the tenth embodiment shown in FIG. A processing device 172 is provided.

FIG. 43 shows the structure of the video processor 173 in the twelfth embodiment. This video processor 17
3 includes a light source device 173A and a signal processing circuit 173B, and the signal processing circuit 173B is the same as the signal processing circuit 83B in FIG.

In the light source device 173A, a filter turret 169 and a rotary filter 170 are provided between the lamp 19 and the light guide 18. The filter turret 169 has two windows formed therein, and a first wavelength limiting filter 86a and a second wavelength limiting filter 169b are attached thereto.

This second wavelength limiting filter 169b
As shown in FIG. 44, it has a characteristic of transmitting only light in a narrow band having a center wavelength of 805 nm. The first wavelength limiting filter 86a has the characteristics described above (see FIG. 30).

The characteristics of each of the color transmission filters 170a, 170, b, and 170c provided in the rotation filter 170 have the characteristics of transmitting the R, G, and B wavelength ranges, respectively, as shown in FIG. Each filter 170
Each of a, 170, b, and 170c has a composite transmission characteristic of transmitting light in an infrared region (around 805 nm).

The other configuration of the video processor 173 is the same as that of the video processor 83 of the tenth embodiment.

The internal configuration of the image processing device 172 is shown in FIG.
Shown in The R, G, and B signals input to the image processing device 172 are converted into A / D converters 171r, 171g, and 171b.
And converted to a digital signal, the LUT1
74r, 174g, and 174b, and are subjected to inverse gamma correction.

The signal subjected to the inverse γ correction is stored in the frame memory 1
75 and LUTs 176r, 176g, 176b. The signals input to the LUTs 176r, 176g, 176b are logarithmically converted and input to the matrix circuit 177. In the matrix circuit 177, a luminance signal is calculated from the RGB signals, and a value Log255 / Y correlated with ICG is calculated.

The calculated value is input to the ROM 178 and the average value calculation circuit 179.
Of the ICG correlation values on the screen,
The average value of pixels belonging to a certain level range (for example, excluding halation and dark areas) is calculated, and ROM 178 is calculated.
Output the result to

In the ROM 178, it is determined from the average value and the ICG correlation value whether the pixel is displayed more or less than the actual ICG amount.
Output to In the ROM 180, for example, the emphasis coefficient data ED input from the front panel or the like further
It is possible to increase and decrease the CG amount. The emphasis coefficient data ED may be input or set by any method as in the tenth embodiment. The signal output from the ROM 180 is input to the ROMs 181r, 181g, and 181b.
The original image output from the frame memory 175 is converted into an enhanced image. The outputs of the ROMs 181r, 181g, 181b are output from the D / A converters 182r, 182g, 182b.
Is converted from a digital signal to an analog signal and output from the image processing device 172.

Next, the operation of this embodiment will be described.
When the first wavelength limiting filter 86a is inserted on the optical path, illumination light in the visible region similar to that described in the tenth embodiment is illuminated on the subject in a time series, so that normal visible observation is possible. When the second wavelength limiting filter 169b is inserted on the optical path, the subject is irradiated with 805-nm infrared narrow-band irradiation light as shown in FIG. 44, and an infrared observation image is obtained. At the time of infrared observation, when ICG is injected intravenously, strong absorption is observed in the blood vessel portion containing the ICG (see FIG. 35 of the tenth embodiment). , Diagnostic ability is improved.

In the image processing device 172, the ICG
By emphasizing the concentration, it is possible to obtain the same effect as when a large amount of ICG is injected intravenously with a small amount of ICG, and it is also possible to reduce the pain for the patient.

This embodiment is not limited to the above method.
After calculating the ICG concentration distribution, band emphasis is performed, and the ICG
A portion where the density changes rapidly may be highlighted. During normal observation, the image processing device 172 may perform an emphasis process on hemoglobin, and the density distribution of hemoglobin dye may be subjected to band emphasis.

Next, a thirteenth embodiment of the present invention will be described. This embodiment is an endoscope apparatus capable of fluorescence observation. FIG.
As shown in the figure, the endoscope apparatus 213 for fluorescence observation of this embodiment
Is provided with an electronic endoscope 201. This electronic endoscope 2
Numeral 01 has an elongated insertion section 202 having, for example, flexibility, and a large-diameter operation section 203 is continuously provided at the rear end of the insertion section 202.

A movable universal cord 204 extends laterally from the rear end of the operation unit 203, and a connector 205 is provided at an end of the universal cord 204. The electronic endoscope 201 is connected to a video processor 206 having a built-in light source device and a signal processing circuit via the connector 205. further,
A monitor 207 is connected to the video processor 206. An image filing device 208 is connected to the video processor 206.

On the distal end side of the insertion portion 202, a rigid distal end portion 209 and a bending portion 210 that can be bent rearward and adjacent to the distal end portion 209 are sequentially provided. By rotating a bending operation knob 211 provided on the operation section 203, the bending section 210 bends in the left-right direction or the up-down direction. The operation unit 20
3 is provided with an insertion port 212 that communicates with a treatment instrument channel provided in the insertion section 202. In addition, for example, a fluorescein solution 192 as a fluorescent agent can be injected into a vein of a living body by a syringe 191.

As shown in FIG. 48, a light guide 2 for transmitting illumination light is provided in an insertion portion 202 of an electronic endoscope 201.
14 is inserted. The distal end surface of the light guide 214 is disposed at the distal end portion 209 of the insertion section 202, and illumination light can be emitted from the distal end surface. Also,
The entrance end of the light guide 14 is a universal cord 2
04 and is connected to the connector 205.

The tip 209 has an objective lens system 2
A solid-state image sensor, for example, a CCD 216, is provided at an image forming position of the objective lens system 215.
Are arranged. A color separation filter array 217 is arranged on the front surface of the CCD 216 on which the imaging surface is provided. The CCD 216 has signal lines 218, 2
The signal lines 218 and 219 are inserted through the insertion portion 202 and the universal cord 204, and are connected to the connector 205.

On the other hand, the video processor 206 has a lamp 2 that emits light in a wide band from ultraviolet light to infrared light.
20 are provided. As the lamp 220, a general xenon lamp, a strobe lamp, or the like can be used. The xenon lamp and the strobe lamp emit a large amount of not only visible light but also ultraviolet light and infrared light.

The lamp 220 is supplied with electric power by the power supply section 221. A rotary filter 223 driven by a motor (M) 222 is provided in front of the lamp 220. This rotary filter 2
23 includes filters 223a, 223b, and 223a that transmit light in the respective wavelength regions of red (R), green (G), and blue (B).
223c are arranged along the circumferential direction. Further, the rotary filter 223 can be inserted and removed from the optical path. Each filter 223a, 223 of the rotation filter 223
FIG. 49 shows the transmission characteristics of b and 223c.

The motor 222 is provided with a motor driver 2
The rotation is controlled and driven by 24. That is, the rotation of the rotation filter 223 is controlled.

The light passes through the rotation filter 223, and R, G, B
The light separated in time series into the light of each wavelength region is incident on the incident end of the light guide 214, and this light guide 2
It is guided to the tip 209 via. The guided light is
The light is emitted from the light guide 214 emission end of the tip 209 to illuminate the observation site.

The optical image of the subject illuminated by the illumination light is formed on the image pickup surface of the CCD 216 by the objective lens system 215. At this time, color separation is performed by the color separation filter array 217. This color separation filter array 217
Are G (green), Cy (cyan),
A color transmission filter of three colors of Ye (yellow) is arranged in a mosaic pattern. FIG. 51 shows transmission characteristics of the G, Cy, and Ye filters. The CCD 216 is read out by applying a drive signal from a driver 225 in the video processor 206.

The signal read from the CCD 216 is amplified by an amplifier 226 in the video processor 206 and then passed through LPFs 227 and 228 and a BPF 229. The LPFs 227 and 228 are, for example, 3 MHz, 0.8
It shows a cutoff characteristic of MHz. The signals passed through them are respectively divided into a high-frequency luminance signal YH and a low-frequency luminance signal YL,
30 and 231, and processing such as gamma correction is performed. High-frequency luminance signal YH passed through process circuit 230
Are subjected to horizontal contour correction, horizontal aperture correction, and the like by the horizontal correction circuit 232 and then input to the color encoder 233. The low-frequency side luminance signal YL passed through the process circuit 231 is input to a matrix circuit 234 for video display, and tracking correction is performed.

On the other hand, by passing through the BPF 229 having a pass band of 3.58 ± 0.5 MHz, a color signal component is extracted from the signal read from the CCD 216, and the color signal component is converted into a 1HDL (1H delay line) 235. , An adder 236 and a subtractor 237, and the color signal component B
And the component R are separated and extracted.

In this case, the output of 1HDL 235 is
The following mixing process is performed. That is, the process circuit 23
1 and the low-frequency side luminance signal YL subjected to vertical aperture correction by the vertical correction circuit 238 and 1HDL 235
Are mixed by the mixer 239.

The mixed output signal is input to an adder 236 and a subtractor 237, where color signals B and R are generated. The color signal B output from the adder 236 and the color signal R output from the subtractor 237 are input to γ correction circuits 240 and 241, respectively. Γ-corrected, and input to demodulators 243 and 244, respectively. Demodulators 243, 24
The signals input to 4 are converted into demodulated color signals B and R, respectively, and then input to the matrix circuit 234.

In the matrix circuit 234, the luminance signal YL
And color signals R and B to generate color difference signals RY and BY. These low-frequency luminance signal YL and color difference signal R-
Y, BY, and the high-frequency luminance signal YH are input to the color encoder 233.

The color encoder 233 outputs the luminance signal YL
, YH, and the color difference signals RY, B-
Y is mixed with a chroma signal that is orthogonally modulated by a subcarrier, and a synchronizing signal (not shown) is superimposed on the mixed signal.
The composite video signal is output from the output terminal. The YL, R, and B signals output from the previous stage of the matrix circuit 234 are converted into RGB signals by the matrix circuit 200 and then input to the signal processing circuit 246.

The driver 225 receives a synchronization signal from the synchronization signal generation circuit 245,
5 is a drive signal synchronized with the synchronizing signal.
Supplied to In the composite video signal, an observation region is displayed in color by the color monitor 207. In the present embodiment, the rotary filter 223 is retracted from the optical path, and a normal visible image can be obtained by irradiating white light.

By the way, if a fluorescent substance such as fluorescein having absorption and fluorescence characteristics as shown in FIG. 52 is injected intravenously while observing the living mucous membrane with a normal color image, the fluorescein in the blood changes with time. The concentration changes. This change depends on changes in blood volume and blood flow.

Here, as shown in FIG. 52, the fluorescein has an absorption characteristic corresponding to the wavelength region of B, and absorbs light of this wavelength to emit fluorescence. Therefore, when the light in the R, G, and B wavelength regions is illuminated in time series by the rotation filter 223, the fluorescence becomes weaker when illuminating R and G than when illuminating by B. That is, for example, when the concentration of fluorescein in the mucous membrane is high during B illumination,
It emits fluorescence in the R and G wavelength regions. Also, at the time of white light illumination, it absorbs light in the B wavelength region and emits fluorescence in the R and G wavelength regions. Therefore, the density distribution of fluorescein and its chronological change can be observed by the change in color tone.

More specifically, as shown in FIG.
The signal processing circuit 246 as shown in FIG. 53 enables observation and measurement of the fluorescent agent concentration distribution with respect to the signal imaged under the illumination of the R, G, and B lights in a state where 23 is arranged on the optical path. It is in.

The signal processing circuit 246 shown in FIG. 53 has R, G, and R output from the matrix circuit 200 (see FIG. 48).
B signal is A / D converter 247r, 247g, 247
b and converted from an analog signal to a digital signal. The R, G, B, and signals converted into digital signals are supplied to LUTs 248r, 24 functioning as an inverse gamma correction circuit.
8g and 248b, and inverse gamma correction is performed.

The outputs of the LUTs 248r, 248g, and 248b are output to the LUTs 249r and 249r, which perform logarithmic conversion.
9g and 249b and the frame memory 256, respectively.

In the LUTs 249r, 249g, and 249b, the logarithm of the fluorescent agent concentration and the hemoglobin concentration and the reflection spectral characteristics have a substantially linear relationship.
The G and B signals are logarithmically converted. LUT249r, 249
g, 249b is formed of, for example, an integrated circuit for logarithmic conversion.

The logarithmically converted R, G, and B signals are input to a fluorescent agent concentration calculation circuit 250, where the fluorescent agent concentration is separated from the hemoglobin concentration and calculated. FIG. 54 shows the configuration of the fluorescent agent concentration calculation circuit 250. The fluorescent agent concentration calculating circuit 250 is a fluorescent intensity calculating circuit 25 for calculating the fluorescent intensity.
0a, a hemoglobin concentration calculation circuit 250b for calculating the hemoglobin concentration, and a normalization circuit 250c for eliminating the influence of the hemoglobin concentration.

In the fluorescence intensity calculation circuit 250a, the fluorescence intensity I
F is calculated by IF = LogRr / Rb. Here, Rr represents an R image in the case of R illumination light, and Rb represents an R image in the case of B illumination light. When fluorescein is used as the fluorescent agent, fluorescence is generated only when the illumination light of B is applied. Therefore, by normalizing the R image when the R illumination light is irradiated, the influence of the illumination light amount can be canceled. At this stage, the effect of the amount of hemoglobin cannot be canceled.

For this reason, the hemoglobin concentration calculating circuit 25
At 0b, the hemoglobin concentration IHb is calculated by IHb = LogRr / Gg. Here, Gg represents a G image at the time of G illumination light.

The fluorescence intensity IF calculated by the fluorescence intensity calculation circuit 250a and the hemoglobin concentration IHb calculated by the hemoglobin concentration calculation circuit 250b are input to a normalization circuit 250c, and the fluorescent agent concentration CIF is calculated by CIF = IF / IHb. You. This fluorescent agent concentration CIF is one in which the influence of the hemoglobin concentration IHb has been canceled.

In this fluorescent agent concentration calculation circuit 250,
The calculated fluorescent agent concentration distribution image is input to the ROM 257 and the average value calculation circuit 258, and the average value calculation circuit 2
At 58, the average value of the concentration of the fluorescent agent in one screen is calculated,
The value is output to the ROM 257.

In the ROM 257, the average value of the fluorescent agent concentration and the fluorescent agent concentration in each pixel are input. This ROM
Reference numeral 257 compares the average value of the fluorescent agent concentration with the fluorescent agent concentration in each pixel, and performs a predetermined conversion described below. That is, the ROM 257 converts the fluorescent agent density value of each pixel into a larger density value when the density value is larger than the average of the fluorescent agent densities, and converts it into a smaller density value when the density value is smaller than the average value. . That is, this RO
M257 performs an emphasis process on the fluorescent agent concentration value for each pixel.

The output of the ROM 257 is input to the ROM 259, and the concentration of the fluorescent agent can be further changed based on information (emphasis coefficient data) from the data input section 291a of the front panel 291. That is,
The ROM 259 can, for example, uniformly enhance or reduce the degree of the fluorescent agent concentration value over the entire screen.

The output of the ROM 259 is the ROM 260r,
260g and 260b, and the frame memory 256
The image whose timing has been adjusted and the enhanced image are stored at the same time. By controlling the reading of the ROMs 260r, 260g, and 260b, for example, an image in which an enhanced image is combined with a normal image can be constructed, and the D / A converter 255r,
255g and 255b.

D / A converters 255r, 255g, 2
The digital signal input to 55b is converted to an R′G′B ′ analog signal, and
The fluorescence-enhanced image and the normal observation image are displayed on the color monitor 207.
Is displayed when the input is switched.

That is, since the above-described composite video signal, for example, NTSC, is also input to the color monitor 207,
By switching between the R'G'B 'signal input from the R, G, B signal input terminal and the NTSC signal input from the NTSC signal input terminal, the endoscope image emphasized by the fluorescent agent concentration distribution can be obtained. And an image in a normal visible region can be selected and observed.

The image filing device 208 can record an image emphasized by the fluorescent agent concentration distribution and a normal image in association with each other, and can also search and display the image.

According to the present embodiment, even with weak fluorescence emission,
Since the emphasizing process is performed, it is possible to effectively capture the characteristics of the fluorescence emission distribution, and it is possible to observe a normal observation image and a portion where the fluorescence is emitted. As a result, in the present embodiment, the hemodynamics of the mucosal surface of the living body can be grasped from the fluorescent agent concentration-weighted image, the observation ability of the lesion can be improved, and the diagnosis ability can be improved.

Next, a fourteenth embodiment of the present invention will be described. This endoscope apparatus is a video processor 20 shown in FIG.
A video processor 306 is used instead of 6. FIG. 55 shows the configuration of the video processor 306. This video processor 306 is the video processor 2 shown in FIG.
At 06, a rotary filter 264 shown in FIG. 56 is arranged instead of the rotary filter 223.

The rotary filter 264 has a B filter 2 that transmits the B wavelength region including the excitation light in the circumferential direction.
64a and a yellow filter 264b that transmits the G and R wavelength regions that do not include the excitation light are provided. FIG. 57 shows the transmission characteristics of these filters.

In this embodiment, the video processor 2
A signal processing circuit 265 whose configuration is shown in FIG. 58 is provided instead of the signal processing circuit 246 in 06.

As shown in FIG. 58, R, G,
The B signal is converted into a digital signal by the A / D converter 266. The converted signal is input to the selector 267, and is input to the fluorescent image frame memory 268 and the yellow image frame memory 269 as a fluorescent image and a yellow image, respectively, by a synchronization signal synchronized with the rotation of the rotation filter 264. Fluorescent image frame memory 2
The output 68 is input to the D / A converter 270, converted into an analog signal, and a fluorescent image is output as an RGB signal.

The output of the B signal from the frame memory 268 is input to the fluorescence intensity normalizing divider 271, the normal visible image frame memory 272, and the D / A converter 273. The output of the R signal from the frame memory 268 is input to the fluorescence intensity normalizing divider 271.

On the other hand, yellow image frame memory 269
Is input to the D / A converter 273, converted into an analog signal, and then output as a normal visible image. The output of the G signal from the frame memory 269 is input to the hemoglobin amount calculation divider 274 and the frame memory for normal visible image 272. The output of the R signal from the frame memory 269 is input to the hemoglobin amount calculation divider 274 and the frame memory for normal visible image 272.

The R / B of the signal input to the fluorescence intensity normalizing divider 271 is calculated, and the fluorescence intensity not affected by the excitation light is output. The R / G of the signal input to the hemoglobin amount calculation divider 274 is calculated, and an index of the hemoglobin amount is output. Divider 271,
Each output of 274 is input to the fluorescence intensity normalizing divider 275, and the fluorescence intensity which is not affected by the amount of hemoglobin is output.

The output of the fluorescence intensity normalizing divider 275 is
The fluorescence intensity is input to the fluorescence intensity conversion ROM 276 and can be enhanced by an externally variable intensity coefficient or the like. The output of the ROM 276 is input to the fluorescence intensity emphasized image conversion ROM 277. ROM 27
7, an output signal of the frame memory 272 for a normal visible image is input. In the ROM 277, the frame memory 2
The fluorescence intensity from ROM 276 is combined with the visible image output from 72 to output a fluorescence intensity emphasized image. ROM
The fluorescence intensity emphasized image output from the 277 is input to the D / A converter 278, converted into an analog signal, and output.

In the other respects, the construction and operation similar to those of the thirteenth embodiment are omitted from the drawings and description, and only different points will be described. Next, the operation of the present embodiment will be described.

The subject illuminated by the rotation filter 264 emits fluorescence in the G and R wavelength regions when illuminated by the B filter 264a. When the illumination light of the yellow filter 264b is illuminated, a yellow image that does not generate fluorescence is obtained. These images are B image, G image with fluorescent light, R image with fluorescent light, G image with no fluorescent light, and no fluorescent light by an image pickup means provided with a color separation filter on a light receiving surface such as a CCD. It can be obtained separated into R images.

[0295] The fluorescence emission image and the yellow image captured in time series are input to the signal processing circuit 265, and are driven by the selector 267 which is driven in synchronization with the rotation filter 264.
Synchronization is performed by the frame memories 268 and 269, respectively. The five synchronized images can be combined into a normal visible image and a fluorescent image by combining them. Further, the dividers 271, 274, and 275 normalize the fluorescence intensity that fluctuates depending on the excitation light intensity and the amount of hemoglobin, and obtain a highly accurate fluorescence intensity value. If the fluorescence intensity value is emphasized and combined with the normal visible image combined by the above-described combination, a fluorescence intensity enhanced image is obtained.

According to the above-described embodiment, a normal visible image, a fluorescent image, and a fluorescent intensity-enhanced image can be obtained without using a dedicated excitation light source or a dedicated fluorescent image pickup unit.

In this embodiment, the fluorescence intensity value is calculated from the R image that emits fluorescence and the B image that is excitation light, but may be calculated from the G image that emits fluorescence and the B image that is excitation light. . It is also possible to calculate both of them to obtain a normalized fluorescence emission image. Further, as the rotation filter, a conventional RGB rotation filter that can illuminate by dividing a wavelength in the visible region into a plurality of regions by time division may be used.

Next, a fifteenth embodiment of the present invention will be described. In this endoscope apparatus, the video processor 20 shown in FIG.
6, a signal processing circuit 246A shown in FIG. 59 is used instead of the signal processing circuit 246.

The input RGB signals are converted from analog signals to digital signals by A / D converters 247r, 247g, 247b. The R, G, and B signals converted to digital signals are supplied to inverse γ correction circuits 288r and 288r.
8g and 288b, and inverse gamma correction is performed. Each output of the inverse γ correction circuit 288r, 288g, 288b is
Each is input to the ROMs 249r, 249g, and 249b.
In the ROMs 249r, 249g, and 249b, since the reflection spectral characteristics of the fluorescent agent concentration and the hemoglobin concentration have a substantially linear relationship by taking a logarithmic axis, the R, G, and B signals are logarithmically converted.

The R, G, and B signals that have been logarithmically converted are input to a matrix circuit 290, where the fluorescent agent concentration is separated from the hemoglobin concentration and calculated. Matrix circuit 290
In, the calculated fluorescent agent concentration distribution image is input to the γ correction circuit 251, and γ correction is performed.

The fluorescent agent concentration distribution image subjected to γ correction is D
The signal is input to the / A converter 252, converted from a digital signal to an analog signal, and output as analog R, G, B signals.

The pseudo R, G, and B signals are supplied to the color monitor 2
07, the fluorescent agent concentration distribution image is displayed in monochrome (because R, G, and B are the same). Further, the color monitor 207 displays the composite video signal such as NTS
C is also input, and by switching between the R, G, B signal input and the NTSC signal input, the fluorescent agent concentration distribution image and the normal observation image can be observed. In addition, the image filing apparatus 208 can record and search for and display the fluorescent agent concentration distribution image and the normal observation image in association with each other.

[0303] In the above configuration, when the rotary filter 223 is not inserted in the optical path in the light source, the signal picked up by the simultaneous picking-up method
In step 06, an NTSC signal, which is a normal image, is output. On the other hand, when the rotary filter 223 is inserted on the optical path, a fluorescent image from the test object, that is, a fluorescent image, that is, R and G light can be displayed on a monitor by illumination light from a B filter (not shown).

As described above, according to this embodiment, the input signal of the color monitor is switched as needed while performing normal observation without the need for a special light source, so that the mucosa of the mucosa after fluorescein intravenous injection is obtained. A time-series change of the fluorescent agent concentration distribution image is obtained. That is, in the present embodiment, the hemodynamics of the mucosal surface of the living body can be grasped, the observation ability of the lesion is improved, and the diagnosis ability is improved. Note that a device for switching between normal observation and fluorescence observation may be provided in the video processor 206.

When the rotary filter 223 is inserted on the optical path as described above, the emission wavelength of the illumination lamp 220 is sequentially restricted, and as shown in FIG. Separated. As a modified example of the present embodiment, it is possible to irradiate the color-separated light to a living mucous membrane surface or the like in a time-series manner to obtain a normal visible light color image. The images taken in time series by the CCD 216 are also configured to be synchronized in the matrix circuit 234.

This synchronizing / matrix circuit synchronizes the low-frequency and high-frequency luminance signals and the respective color signals obtained in time series with, for example, a memory (not shown). At this time, as for the luminance component, the low-frequency and high-frequency luminance components obtained for each illumination color are respectively added by, for example, an adder (not shown) to obtain luminance signals YL and YH, respectively.

Further, the synchronizing / matrix circuit generates color difference signals RY and BY using the synchronized luminance signal YL and chrominance signals R and B. Then, the low-frequency luminance signal YL and the color difference signals RY and BY and the high-frequency luminance signal YH are input to the color encoder 233, and the same processing is performed.

According to this modification, the time series of the fluorescent agent concentration distribution image of the mucous membrane after intravenous injection of fluorescein is obtained by switching the input signal of the color monitor while performing normal observation without requiring a special light source. The objective change is obtained.

Note that reading may be controlled by a drive signal to achieve synchronization. Also, the matrix circuit 29
In the same manner as the above-described synchronization / matrix, 0 may be configured so that images taken in time series are also synchronized.

FIG. 60 shows a signal processing circuit 246B according to a sixteenth embodiment of the present invention. The fluorescence observation endoscope apparatus of the present embodiment has a signal processing circuit 246B instead of the signal processing circuit 246 of the thirteenth embodiment. Otherwise, the same configurations and operations as those of the thirteenth embodiment are denoted by the same reference numerals, description thereof will be omitted, and only different points will be described.

The signal processing circuit 246B shown in FIG.
The components from the D converters 247r, 247g, 247b to the matrix circuit 290 are the same as those in FIG. The R, G, and B signals that have undergone logarithmic conversion are input to the matrix circuit 290, and the fluorescent agent concentration is separated from the hemoglobin concentration and calculated by the matrix circuit 290.

The fluorescent agent concentration distribution images calculated by the matrix circuit 290 are stored in ROMs 253r and 253, respectively.
g, 253b and converted into a pseudo-color image. For example, conversion processing is performed so that pixels having a high fluorescent agent concentration are displayed in red, and pixels having a low fluorescent agent concentration are displayed in blue.

Here, the image converted into the pseudo color image is input to γ correction circuits 254r, 254g, 254b, and γ correction is performed. The pseudo-color image of the fluorescent agent distribution subjected to the γ correction is output to the D / A converters 255r and 25r.
5g and 255b, converted from a digital signal to an analog signal, and input to the color monitor 207.
In the color monitor 207, by switching between the R, G, B signal input and the NTSC signal, it becomes possible to observe the fluorescent agent distribution pseudo color image and the normal observation image.

According to the present embodiment, as in the fifteenth embodiment, the input signal of the color monitor 207 is switched while performing normal observation without the need for a special light source. Of the fluorescent agent concentration distribution image of FIG. In addition, since the fluorescent agent concentration distribution is colored in a pseudo color, differences in the fluorescent agent concentration between pixels can be clarified, so that the hemodynamics of the mucosal surface of the living body can be grasped, and the observation ability of the lesion can be improved. In addition, the diagnostic ability can be improved.

FIG. 61 shows the structure of a video processor according to the seventeenth embodiment of the present invention. The fluorescence observation endoscope apparatus of the seventeenth embodiment differs from the video processor 206 of the thirteenth embodiment in that a video processor 206 shown in FIG.
A is provided. This video processor 206A is different from video processor 264 in FIG.
And a function of irradiating infrared light.

In the video processor 206A, the lamp 2
A filter turret 261 shown in FIG. 62 is arranged between the rotary filter 20 and the rotary filter 223. The filter turret 261 includes an infrared BPF (bandpass filter) 262a having transmission characteristics shown in FIG. 63 and an opening 262b without a filter. Infrared BPF262
“a” efficiently transmits only the infrared light band of the light emitted from the lamp 20.

The filter turret 261 is
The rotation of 3 controls the position of each filter. In other words, the motor 263 moves either the portion of the opening 62b without a filter or the infrared BPF 262a so as to be inserted into the optical path.

Next, the operation of the present embodiment will be described.
In the present embodiment, when the filter-free opening 262b of the filter turret 261 is set on the optical path,
It has the same operation and effect as the fifteenth embodiment. That is, normal plane-sequential illumination light is applied.

The infrared BPF2 of the filter turret 261
When 62a is set on the optical path, the rotary filter 223 is retracted from the optical path to increase the amount of light, so that infrared light is illuminated, and an infrared observation image is obtained.

[0320] If an ultraviolet BPF transmitting the ultraviolet wavelength region is provided instead of the infrared BPF 262a, ultraviolet observation is also possible. Alternatively, if both BPFs are provided, it is possible to perform both infrared observation and ultraviolet observation. Further, in this embodiment, the blue wavelength region provided in the rotary filter contains the excitation light, but the excitation light BPF that transmits the excitation light wavelength region may be provided in the filter turret.

According to this embodiment, the same effects as those of the fifteenth embodiment can be obtained, and at the same time, an infrared observation image can be obtained, so that the observability of a lesion or the like can be further improved. .

The configuration of the signal processing section is not limited to that of the fifteenth embodiment, but may be the configuration of the sixteenth embodiment. Further, other signal processing may be performed. Note that in the thirteenth embodiment and thereafter, the same effect can be obtained with a fluorescent agent other than fluorescein, for example, a hematoporphyrin derivative, acridine orange, adreamycin, or the like. In this case, any fluorescent agent absorbs light having the wavelength of B, but the acridine orange and hematoporphyrin derivatives emit light in the wavelength region from R to the near infrared.

For this reason, observation is difficult with a fiberscope, but is clearly observable with a videoscope.
In the embodiment, the video processor 6
Although the signal processing circuit is provided therein, the signal processing circuit may be made independent and configured separately as an image processing unit.

Alternatively, the image filing device 208 capable of searching for a recorded image may be connected, and a signal processing circuit may be provided in the image filing device 8. It is also possible to observe the concentration of the fluorescent agent in the tissue instead of the fluorescent agent in the blood vessel, and it is also possible to observe the change in NADH and the intrinsic fluorescence of the living tissue without using the fluorescent agent.

Further, the present invention is not limited to an electronic endoscope having a solid-state image pickup device at the distal end of the insertion section, but also includes a fiberscope
Applicable to the eyepiece of an endoscope that can be observed with the naked eye such as a rigid endoscope, or to an endoscope that is used by connecting to an external TV camera having a solid-state image sensor such as a CCD by replacing the eyepiece can do.

Further, by providing processing circuits of the simultaneous mode and the frame sequential mode in the camera control unit and changing the illuminating light of the light source, a normal color image and infrared observation can be performed by the frame sequential scope. Usually, a system for performing fluorescence and infrared observation may be used. It is also possible to configure different embodiments by combining the above-described embodiments and the like, and these also belong to the present invention.

[0327]

As described above, according to the present invention, a dye amount calculating means for calculating a dye amount for an image signal corresponding to an endoscope image obtained by using an endoscope, and the dye amount calculating means Based on the amount of dye calculated in step (a), there is provided an emphasizing unit that performs an emphasizing process on the image, and a display unit that displays the emphasized image processed by the emphasizing unit. The endoscope image makes it easy to identify a lesion or the like from a normal part.

[Brief description of the drawings]

FIG. 1 is a side view showing an entire endoscope apparatus including a first embodiment.

FIG. 2 is a block diagram showing the configuration of FIG.

FIG. 3 is a characteristic diagram showing transmission characteristics of a color transmission filter.

FIG. 4 is a block diagram illustrating a configuration of an image enhancement unit.

FIG. 5 is an explanatory diagram showing an enhancement processing function by an image enhancement unit.

FIG. 6 is a flowchart showing the entire image enhancement method.

FIG. 7 is a flowchart of a hemoglobin amount calculation process and an average value calculation process.

FIG. 8 is a flowchart of an enhanced image creation process.

FIG. 9 is a side view showing the entire endoscope apparatus having a modification of the first embodiment.

FIG. 10 is a flowchart of a hemoglobin amount calculation process and an average value calculation process in the second embodiment.

FIG. 11 is a flowchart of an enhanced image creation process.

FIG. 12 is a side view showing the entire endoscope apparatus having the third embodiment.

FIG. 13 is a block diagram illustrating a configuration of an image processing unit.

FIG. 14 is a block diagram illustrating a configuration of an image enhancement unit according to a modification of the third embodiment.

FIG. 15 is a block diagram illustrating a configuration of an image enhancement unit according to a fourth embodiment of the present invention.

FIG. 16 is a block diagram illustrating a configuration of an image enhancement unit according to a modification of the fourth embodiment.

FIG. 17 is a block diagram illustrating a configuration of an image enhancement unit according to a fifth embodiment.

FIG. 18 is a characteristic diagram showing conversion characteristics of an enhancement coefficient conversion table.

FIG. 19 is a block diagram showing a configuration of an image enhancement unit according to a sixth embodiment of the present invention.

FIG. 20 is a block diagram illustrating a configuration of an image enhancement unit according to a seventh embodiment of the present invention.

FIG. 21 is a block diagram illustrating a configuration of an image enhancement unit according to an eighth embodiment.

FIG. 22 is an explanatory diagram of a histogram enlargement process.

FIG. 23 is a block diagram illustrating a configuration of an image enhancement unit according to a ninth embodiment.

FIG. 24 is a flowchart showing processing contents of an emphasis processing unit;

FIG. 25 is an explanatory diagram showing an example of a weighting function used for performing filtering.

FIG. 26 is a configuration diagram showing an entire endoscope apparatus according to a tenth embodiment.

FIG. 27 is a block diagram illustrating a configuration of a video processor.

FIG. 28 is an explanatory diagram showing transmission characteristics of a color transmission filter of a rotation filter.

FIG. 29 is an explanatory diagram showing a configuration of a filter turret.

FIG. 30 is an explanatory diagram showing transmission characteristics of two wavelength limiting filters of a filter turret.

FIG. 31 is an explanatory diagram showing the wavelength of illumination light emitted by a first wavelength limiting filter and a rotation filter.

FIG. 32 is an explanatory diagram showing the wavelength of illumination light emitted by a second wavelength limiting filter and a rotation filter.

FIG. 33 is a block diagram illustrating a configuration of an image processing apparatus.

FIG. 34 is a block diagram showing a configuration of an ICG density calculation circuit.

FIG. 35 is a characteristic diagram showing an absorption spectrum of ICG.

FIG. 36 is a flowchart showing processing for generating an image in which ICG density is emphasized;

FIG. 37 is a configuration diagram showing the entire endoscope apparatus according to the eleventh embodiment.

FIG. 38 is a block diagram illustrating a configuration of a video processor.

FIG. 39 is an explanatory diagram showing a configuration of a color separation filter array arranged on the front surface of the CCD.

FIG. 40 is an explanatory diagram showing transmission wavelength characteristics of each transmission filter of the color separation filter array.

FIG. 41 is an explanatory diagram showing the wavelength of illumination light emitted by the first wavelength limiting filter.

FIG. 42 is an explanatory diagram showing the wavelength of illumination light emitted by a second wavelength limiting filter.

FIG. 43 is a block diagram illustrating a configuration of a video processor.

FIG. 44 is an explanatory diagram showing transmission wavelength characteristics of a second wavelength limiting filter provided in a filter turret.

FIG. 45 is an explanatory diagram showing transmission wavelength characteristics of each filter provided in the rotary filter.

FIG. 46 is a block diagram illustrating a configuration of an image processing apparatus.

FIG. 47 is a schematic configuration diagram showing the entire endoscope apparatus for fluorescence observation.

FIG. 48 is a block diagram illustrating a configuration of a video processor.

FIG. 49 is a characteristic diagram showing a transmission wavelength region of each filter attached to the rotary filter.

FIG. 50 is an explanatory diagram of a color separation filter array.

FIG. 51 is a characteristic diagram showing transmission characteristics of each filter of the color separation filter array.

FIG. 52 is a characteristic diagram showing absorption and fluorescence of fluorescein as a fluorescent agent.

FIG. 53 is a block diagram showing a configuration of a signal processing circuit for observing and measuring the concentration distribution of a fluorescent agent.

FIG. 54 is a block diagram of a fluorescent agent concentration calculation circuit.

FIG. 55 is a block diagram showing a configuration of a signal processing circuit according to a fourteenth embodiment.

FIG. 56 is an explanatory view showing a rotation filter.

FIG. 57 is a characteristic diagram showing a transmission wavelength region of each filter attached to the rotary filter.

FIG. 58 is a block diagram illustrating a configuration of a signal processing circuit.

FIG. 59 is a block diagram showing a configuration of a signal processing circuit according to a fifteenth embodiment.

FIG. 60 is a block diagram showing a configuration of a signal processing circuit according to a sixteenth embodiment.

FIG. 61 is a block diagram showing a configuration of a video processor in a seventeenth embodiment.

FIG. 62 is an explanatory diagram showing a configuration of a filter turret.

FIG. 63 is a characteristic diagram showing transmission characteristics of an infrared BPF.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 1/00 A61B 1/32

Claims (1)

(57) [Claims] 1. A distribution of an amount of at least one dye with respect to an image signal corresponding to an endoscope image obtained by using an endoscope.
A dye amount distribution calculating means for calculating the dye amount, and a dye amount calculated by the dye amount distribution calculating means,
Dye amount setting to replace deviation from reference value with expanded dye amount
Endoscopic, characterized in that it comprises a switching means, and enhancement means for performing enhancement processing on the image by the amount the magnified substituted dye, and display means for displaying the emphasis processing has been emphasis processing image with the enhancement means Mirror image processing device.