JP4409523B2 - Biological observation device - Google Patents

Description

  The present invention relates to a living body observation apparatus that generates a spectral image signal corresponding to a pseudo narrow band filter by signal processing using a color image signal obtained by imaging a living body and displays the spectral image signal on a monitor as a spectral image. .

  2. Description of the Related Art Conventionally, endoscope apparatuses that obtain an endoscopic image in a body cavity by irradiating illumination light have been widely used as living body observation apparatuses. In this type of endoscope apparatus, an electronic endoscope having an image pickup unit that guides illumination light from a light source device into a body cavity using a light guide or the like and picks up an image of a subject using the return light is used. An image signal from the imaging means is signal-processed to display an endoscopic image on an observation monitor and observe an observation site such as an affected area.

  When performing normal biological tissue observation in an endoscopic device, one method is to emit white light in the visible light region with a light source device, and use, for example, a rotation filter such as RGB to subject the surface sequential light to the subject. A color image is obtained by irradiating and image-processing the return light by the frame sequential light with a video processor. When performing normal biological tissue observation in an endoscope apparatus, as another method, a color chip is arranged in front of the imaging surface of the imaging means of the endoscope, and white light in the visible light region is emitted by the light source device. Is emitted, and the return light by the white light is imaged by separating each color component with a color chip, and a color image is obtained by image processing with a video processor.

  Since living tissue has different light absorption characteristics and scattering characteristics depending on the wavelength of light to be irradiated, for example, in Japanese Patent Application Laid-Open No. 2002-95635, illumination light in the visible light region is converted into a narrow-band RGB surface having discrete spectral characteristics. A narrow-band optical endoscope apparatus that sequentially irradiates light to a living tissue and obtains tissue information of a desired deep portion of the living tissue has been proposed.

  Japanese Patent Laid-Open No. 2003-93336 discloses a narrowband optical endoscope that generates a discrete spectral image by performing signal processing on an image signal generated by illumination light in a visible light region and obtains tissue information of a desired deep part of a living tissue. A device has been proposed.

In the apparatus described in the above-mentioned Japanese Patent Application Laid-Open No. 2003-93336, a color image signal (or a biological signal) picked up in a wide wavelength band is used (pseudo) without using an optically narrow band-pass filter. A process of generating a spectral image signal as obtained when using a narrow band-pass filter is performed by an electric calculation process by matrix calculation (corresponding to a narrow band-pass filter).
JP 2002-95635 A JP 2003-93336 A

However, in the apparatus described in Japanese Patent Application Laid-Open No. 2003-93336, if the biological tissue to be observed is different, the spectral reflection characteristics are different, and the generated spectral image signal is fluctuated. There are drawbacks such as a decrease in signal accuracy.
For example, the esophageal mucosa and the mucosa of the stomach or large intestine are different in the type of mucosal tissue (for example, the esophageal mucosa is a stratified squamous epithelium and the stomach is a single-layered columnar epithelium). In contrast, there is a drawback that the generated spectral image signal fluctuates.

Further, the apparatus described in Japanese Patent Application Laid-Open No. 2003-93336 has a drawback that the color tone when the spectral image signal is displayed on the display means or the display output apparatus cannot be changed.
As described above, the apparatus described in Japanese Patent Application Laid-Open No. 2003-93336 has an advantage of electrically generating a spectral image signal from a color image signal, but further converts the spectral image signal into a color tone desired by the user or an appropriate color tone. It is desirable to be equipped with interface means that can improve operability, such as conversion and display, or switching between color image signals (normal image signals) and spectral image signals.

(Object of invention)
The present invention has been made in view of the above-described points, and has a function of electrically generating a spectral image signal from a color image signal. Further, the spectral image signal can be adapted to a case where a living tissue or the like is different, An object of the present invention is to provide a living body observation apparatus capable of improving operability related to observation of a spectral image.

The first living body observation apparatus of the present invention is a first imaging signal obtained by imaging a subject illuminated with white illumination light with a first imaging apparatus including a plurality of broadband color filters having wavelength transmission characteristics. Alternatively, the display device performs signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in a plurality of different broadband wavelength regions covering the visible region by the second imaging device. A color image signal generation unit that generates a color image signal to be displayed as a color image, and a color signal used to generate the color image signal or the color based on the first imaging signal or the second imaging signal Spectral image signals corresponding to narrow-band image signals obtained when imaging a subject illuminated with illumination light in a narrow-band wavelength region through signal processing on the image signals A spectral image signal generation unit that generates a signal, a display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on a display device, and the spectral image in the spectral image signal generation unit A characteristic change setting unit for changing and setting a signal generation characteristic, a display color change setting unit for changing and setting the display color conversion, and an instruction operation for switching and / or confirming information including an image displayed on the display device At least one of the interface unit, and the characteristic change setting unit is configured to capture images by the first imaging device or the second imaging device, and the first imaging device or the second imaging device. On the basis of information corresponding to at least one of the light source unit that generates the illumination light used for the above, the change setting of the generation characteristic by the characteristic change setting unit is performed automatically or manually. The features. The second living body observation device of the present invention is a first imaging signal obtained by imaging a subject illuminated with white illumination light by a first imaging device having a plurality of broadband color filters with wavelength transmission characteristics. Alternatively, the display device performs signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in a plurality of different broadband wavelength regions covering the visible region by the second imaging device. A color image signal generation unit that generates a color image signal to be displayed as a color image, and a color signal used to generate the color image signal or the color based on the first imaging signal or the second imaging signal Spectral image corresponding to narrow-band image signal obtained when imaging a subject illuminated with illumination light in a narrow-band wavelength region by signal processing on the image signal A spectral image signal generation unit that generates a signal, a display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on a display device, and the spectral image in the spectral image signal generation unit A characteristic change setting unit for changing and setting a signal generation characteristic, a display color change setting unit for changing and setting the display color conversion, and an instruction operation for switching and / or confirming information including an image displayed on the display device And the spectral image signal generation unit has a coefficient storage unit that stores a plurality of coefficients for changing the generation characteristics of the spectral image signal, and the characteristic change setting unit includes: A coefficient switching setting unit that switches and sets a coefficient used for the change setting of the generation characteristic with respect to the coefficient storage unit. According to a third living body observation apparatus of the present invention, in the second living body observation apparatus, the plurality of coefficients stored in the coefficient storage unit are types corresponding to spectral reflection characteristics of a living body as the subject, or It includes a plurality of biometric coefficients corresponding to the name of the site to be observed in the living body or the type of mucosal tissue of the living body. According to a fourth living body observation apparatus of the present invention, in the second living body observation apparatus, the plurality of coefficients stored in the coefficient storage unit correspond to a plurality of different feature quantities in the living body as the subject. It includes a plurality of feature amount coefficients for changing the generation characteristics of the spectral image signal. According to a fifth living body observation apparatus of the present invention, in the fourth living body observation apparatus, the feature amount coefficient is the spectral image signal for observing a blood vessel structure distributed in a depth direction from the surface of the living body. It is set to the coefficient for blood vessels to be generated.
The sixth living body observation device of the present invention is a first imaging signal obtained by imaging a subject illuminated with white illumination light by a first imaging device including a plurality of broadband color filters having wavelength transmission characteristics. Alternatively, signal processing is performed on the second imaging signal obtained by imaging the subject illuminated by the surface-sequential illumination light in a plurality of different broadband wavelength regions covering the visible region with the second imaging device, and the display device A color image signal generation unit that generates a color image signal to be displayed as a color image, and a color signal used to generate the color image signal or the color based on the first imaging signal or the second imaging signal Spectral image corresponding to narrow-band image signal obtained when imaging a subject illuminated with illumination light in a narrow-band wavelength region by signal processing on the image signal A spectral image signal generation unit that generates a signal, a display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on a display device, and the spectral image in the spectral image signal generation unit A characteristic change setting unit for changing and setting a signal generation characteristic, a display color change setting unit for changing and setting the display color conversion, and an instruction operation for switching and / or confirming information including an image displayed on the display device The display color change setting unit includes a coefficient storage unit that stores a plurality of conversion coefficients for changing the characteristics of the display color conversion, and the display color conversion unit. A coefficient switching setting unit that switches and sets conversion coefficients used for conversion of conversion coefficients used for display color conversion, and the plurality of conversion coefficients stored in the coefficient storage unit Inspection As a feature quantity coefficient corresponding to a plurality of feature quantities having different spectral reflection characteristics in the living body, and the feature quantity coefficient is used for observing a blood vessel structure distributed in a depth direction from the surface of the living body. It is set to a blood vessel coefficient for setting the display color of the spectral image signal.
The seventh living body observation device of the present invention is a first imaging signal obtained by imaging a subject illuminated with white illumination light with a first imaging device including a plurality of broadband color filters having wavelength transmission characteristics. Alternatively, signal processing is performed on the second imaging signal obtained by imaging the subject illuminated by the surface-sequential illumination light in a plurality of different broadband wavelength regions covering the visible region with the second imaging device, and the display device A color image signal generation unit that generates a color image signal to be displayed as a color image, and a color signal used to generate the color image signal or the color based on the first imaging signal or the second imaging signal Spectral image corresponding to narrow-band image signal obtained when imaging a subject illuminated with illumination light in a narrow-band wavelength region by signal processing on the image signal A spectral image signal generation unit that generates a signal, a display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on a display device, and the spectral image in the spectral image signal generation unit A characteristic change setting unit for changing and setting a signal generation characteristic, a display color change setting unit for changing and setting the display color conversion, and an instruction operation for switching and / or confirming information including an image displayed on the display device And a brightness determination unit that determines whether or not the brightness in the spectral image signal is equal to or lower than a reference value, and the spectral determination is performed according to a determination result by the brightness determination unit. The generation characteristic of the image signal is switched.
The eighth living body observation apparatus of the present invention is a first imaging signal obtained by imaging a subject illuminated with white illumination light with a first imaging apparatus having a plurality of broadband color filters having wavelength transmission characteristics. Alternatively, the display device performs signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in a plurality of different broadband wavelength regions covering the visible region by the second imaging device. A color image signal generation unit that generates a color image signal to be displayed as a color image, and a color signal used to generate the color image signal or the color based on the first imaging signal or the second imaging signal Spectral image corresponding to narrow-band image signal obtained when imaging a subject illuminated with illumination light in a narrow-band wavelength region by signal processing on the image signal A spectral image signal generation unit that generates a signal, a display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on a display device, and the spectral image in the spectral image signal generation unit A characteristic change setting unit for changing and setting a signal generation characteristic, a display color change setting unit for changing and setting the display color conversion, and an instruction operation for switching and / or confirming information including an image displayed on the display device And a brightness determination unit that outputs a determination signal when the brightness in the spectral image signal is equal to or lower than a reference value, and an image displayed on the display device by the determination signal Is forcibly switched from the spectral image to the color image.
A ninth living body observation apparatus of the present invention is a first imaging signal obtained by imaging a subject illuminated with white illumination light with a first imaging apparatus having a plurality of broadband color filters having wavelength transmission characteristics. Alternatively, the display device performs signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in a plurality of different broadband wavelength regions covering the visible region by the second imaging device. A color image signal generation unit that generates a color image signal to be displayed as a color image, and a color signal used to generate the color image signal or the color based on the first imaging signal or the second imaging signal Spectral image corresponding to narrow-band image signal obtained when imaging a subject illuminated with illumination light in a narrow-band wavelength region by signal processing on the image signal A spectral image signal generation unit that generates a signal, a display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on a display device, and the spectral image in the spectral image signal generation unit A characteristic change setting unit for changing and setting a signal generation characteristic, a display color change setting unit for changing and setting the display color conversion, and an instruction operation for switching and / or confirming information including an image displayed on the display device And a color tone determination unit that determines whether or not the spectral image signal corresponds to a predetermined color tone value, and according to a determination result by the color tone determination unit, the spectral image The signal generation characteristic is switched.
The tenth biological observation apparatus of the present invention is a first imaging signal obtained by imaging a subject illuminated with white illumination light with a first imaging apparatus provided with a plurality of broadband color filters having wavelength transmission characteristics. Alternatively, the display device performs signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in a plurality of different broadband wavelength regions covering the visible region by the second imaging device. A color image signal generation unit that generates a color image signal to be displayed as a color image, and a color signal used to generate the color image signal or the color based on the first imaging signal or the second imaging signal Spectral image corresponding to narrowband image signal obtained when imaging a subject illuminated by illumination light in a narrowband wavelength region by signal processing on the image signal A spectral image signal generation unit that generates a signal; a display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on a display device; and the spectral image in the spectral image signal generation unit A characteristic change setting unit for changing and setting a signal generation characteristic, a display color change setting unit for changing and setting the display color conversion, and an instruction operation for switching and / or confirming information including an image displayed on the display device And a color tone determination unit that determines whether or not the spectral image signal corresponds to a predetermined color tone value, and the color tone determination unit is configured to stain the subject for staining. A specific color tone value detection unit that detects a specific color tone value when at least one of a pigment, a residue, and bile is present, and the specific color tone value detected by the specific color tone value detection unit is a predetermined amount or more In, wherein the forced switch over the spectral image displayed on the display device to the color image.
According to an eleventh biological observation apparatus of the present invention, a first imaging signal is obtained by imaging a subject illuminated with white illumination light with a first imaging device having a plurality of broadband color filters with wavelength transmission characteristics. Alternatively, signal processing is performed on the second imaging signal obtained by imaging the subject illuminated by the surface-sequential illumination light in a plurality of different broadband wavelength regions covering the visible region with the second imaging device, and the display device A color image signal generation unit that generates a color image signal to be displayed as a color image, and a color signal used to generate the color image signal or the color based on the first imaging signal or the second imaging signal Spectral image corresponding to narrowband image signal obtained when imaging a subject illuminated by illumination light in a narrowband wavelength region by signal processing on the image signal A spectral image signal generation unit that generates a signal; a display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on a display device; and the spectral image in the spectral image signal generation unit A characteristic change setting unit for changing and setting a signal generation characteristic, a display color change setting unit for changing and setting the display color conversion, and an instruction operation for switching and / or confirming information including an image displayed on the display device At least one of the interface unit, and the characteristic change setting unit detects a difference between a light source type mounted on the light source unit that generates the illumination light and a difference in spectral characteristics / A spectral characteristic detection unit is provided, and the generation characteristic of the spectral image signal is changed according to a detection result by the light source type / spectral characteristic detection unit.

  With the above configuration, it has a function to electrically generate a spectral image signal from a color image signal, and further, the display color of the spectral image can be changed, and the characteristics of the generated spectral image signal can be changed according to the living tissue or the like. It is possible to improve the operability by responding or checking the image displayed on the display device.

  According to the present invention, a function of electrically generating a spectral signal from a biological signal is provided, and further, the display color of the spectral image is changed, and the characteristics of the generated spectral image signal can be changed by changing according to the biological tissue or the like. And the image displayed on the display device can be confirmed, and the operability can be improved.

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

FIG. 1 to FIG. 34 relate to Embodiment 1 of the present invention, FIG. 1 is a conceptual diagram showing a signal flow when creating a spectral image signal from a color image signal, and FIG. 2 is a conceptual diagram showing an integration operation of the spectral image signal. 3 is an external view showing the external appearance of the electronic endoscope apparatus, FIG. 4 is a block diagram showing the configuration of the electronic endoscope apparatus of FIG. 3, and FIG. 5 is an external view showing the external appearance of the chopper of FIG. 6 is a diagram showing the arrangement of color filters arranged on the imaging surface of the CCD shown in FIG. 3, FIG. 7 is a diagram showing spectral sensitivity characteristics of the color filters shown in FIG. 6, and FIG. 8 is a diagram showing the configuration of the matrix calculation unit shown in FIG. 9 is a spectrum diagram showing a spectrum of a light source, and FIG. 10 is a spectrum diagram showing a reflection spectrum of a living body.
FIG. 11 is a diagram showing a layer direction structure of the biological tissue observed by the electronic endoscope apparatus of FIG. 4, and FIG. 12 is a diagram illustrating the arrival of illumination light from the electronic endoscope apparatus of FIG. 4 in the layer direction of the biological tissue. FIG. 13 is a diagram showing the spectral characteristics of each band of white light, FIG. 14 is a first diagram showing each band image by white light in FIG. 13, and FIG. 15 is each diagram by white light in FIG. FIG. 16 is a third diagram showing each band image by white light in FIG. 13, FIG. 17 is a diagram showing the spectral characteristics of the spectral image generated by the matrix calculation unit in FIG. 18 is a first diagram showing the spectral images of FIG. 17, FIG. 19 is a second diagram showing the spectral images of FIG. 17, and FIG. 20 is a third diagram showing the spectral images of FIG.

21 is a block diagram showing the configuration of the color adjustment unit in FIG. 4, FIG. 22 is a diagram for explaining the operation of the color adjustment unit in FIG. 21, and FIG. 23 shows a modification of the color adjustment unit in FIG. FIG. 24 is a diagram showing the spectral characteristics of the first modified example of the spectral image of FIG. 17, FIG. 25 is a diagram showing the spectral characteristics of the second modified example of the spectral image of FIG. 17, and FIG. It is a figure which shows the spectral characteristic of the 3rd modification of this spectral image.
FIG. 27 is a flowchart showing an operation of manually switching coefficients when switching to the spectral image observation mode. FIG. 28 is a diagram showing a modification of the electronic endoscope apparatus in which the coefficients are switched by a centralized controller or voice input. FIG. 29 is a block diagram showing the configuration of an electronic endoscope apparatus when an ID memory is provided in a scope or the like. FIG. 30 is a block diagram showing coefficient switching by combination on the apparatus side in the case of the configuration of FIG. FIG. 31 is a flowchart showing a part of the operation for displaying the observation mode in the case of the operation of FIG. 30, and FIG. 32 explicitly shows the observation mode when the normal image and the spectral image are displayed. FIG. 33 is a flowchart of the operation for changing and setting the parameters in conjunction with the switching of the observation mode in the case of the configuration of FIG. 29, and FIG. Is a flowchart showing part of operation in the example.

  In the electronic endoscope apparatus as the living body observation apparatus according to the first embodiment of the present invention, the imaging light is emitted from the illumination light source to the living body that is the subject and reflected from the living body based on the irradiated light. A wide-band color image signal is generated from an image signal that is received and photoelectrically converted by a solid-state image sensor, and a spectral image signal corresponding to an image signal with a narrow optical wavelength is signal-processed from the color image signal. Generate by.

  Hereinafter, before describing Example 1 according to the present invention, a matrix calculation method as a basis of the present invention will be described. Here, the matrix is a predetermined coefficient used when generating a spectral image signal from a color image signal acquired to generate a color image (hereinafter referred to as a normal image).

  Further, following the description of this matrix, a correction method for obtaining a more accurate spectral image signal and an S / N improvement method for improving the S / N of the generated spectral image signal will be described. The correction method and the S / N improvement method may be used as necessary. In the following, vectors and matrices (matrix) are indicated by bold characters or “” (for example, the matrix A is expressed as “A bold character of A” or “A” ”), and the others are expressed without character modification.

(Matrix calculation method)
FIG. 1 shows a color image signal (here, R, G, and B for simplicity of explanation, but in a complementary color solid-state imaging device as in the embodiments described later, G, Cy, Mg, FIG. 4 is a conceptual diagram showing a signal flow when generating a spectral image signal corresponding to an optical wavelength narrow band image from a combination of Ye).

  First, the electronic endoscope apparatus converts the color sensitivity characteristics of R, G, and B into numerical data. Here, the color sensitivity characteristics of R, G, and B are output characteristics with respect to wavelengths obtained when a white object is imaged using a white light source.

  The color sensitivity characteristics of R, G, and B are shown on the right side of each image data as a simplified graph. Further, the color sensitivity characteristics of R, G, and B at this time are assumed to be n-dimensional column vectors “R”, “G”, and “B”, respectively.

  Next, the electronic endoscope apparatus has a narrow band Pand pass filter F1, F2, F3 for spectral images to be extracted (the electronic endoscope apparatus knows the characteristics of a filter that can efficiently extract the structure as foresight information. The characteristics of this filter are those whose wavelength bands are approximately 590 nm to approximately 610 nm, approximately 530 nm to approximately 550 nm, and approximately 400 m to approximately 430 nm, respectively.

となるマトリックスの要素を求めればよい。 Here, “substantially” is a concept including about ± 10 nm in wavelength. The filter characteristics at this time are n-dimensional column vectors “F ₁ ”, “F ₂ ”, and “F ₃ ”, respectively. Based on the obtained numerical data, an optimum coefficient set that approximates the following relationship is obtained. That is,
[Equation 1]

What is necessary is just to obtain the elements of the matrix.

となる。従って、（１）式に示した命題は、以下の関係を満足する係数マトリックス「Ａ」を求めるに等しい。 The solution of the above optimization proposition is given mathematically as follows: Performing principal component analysis or orthogonal expansion (or orthogonal transformation), “C” for the matrix representing the color sensitivity characteristics of R, G, and B, “F” for the spectral characteristics of the narrowband Pandpass filter to be extracted If the coefficient matrix to be calculated is “A”,
[Equation 2]

It becomes. Therefore, the proposition shown in the equation (1) is equivalent to obtaining a coefficient matrix “A” that satisfies the following relationship.

ここで、分光特性を表すスペクトルデータとしての点列数nとしては、n＞３であるので、（３）式は１次元連立方程式ではなく、線形最小二乗法の解として与えられる。即ち、（３）式から擬似逆行列を解けばよい。マトリックス「Ｃ」の転置行列を「^ｔＣ」とすれば、（３）式は
［数４］

となる。「^ｔＣＣ」はn×nの正方行列であるので、（４）式は係数マトリックス「Ａ」についての連立方程式と見ることができ、その解は、
［数５］

で与えられる。 [Equation 3]

Here, since the number of point sequences n as spectral data representing spectral characteristics is n> 3, equation (3) is not a one-dimensional simultaneous equation but is given as a solution of the linear least square method. That is, the pseudo inverse matrix may be solved from the equation (3). Assuming that the transposed matrix of the matrix “C” is “ ^t C”, the equation (3) is expressed as

It becomes. Since “ ^t CC” is an n × n square matrix, equation (4) can be viewed as a simultaneous equation for the coefficient matrix “A”, and its solution is
[Equation 5]

Given in.

  With respect to the coefficient matrix “A” obtained by the equation (5), the electronic endoscope apparatus performs the conversion of the left side of the equation (3) to thereby obtain the characteristics of the narrow band Pandpass filters F1, F2, and F3 to be extracted. Can be approximated. The above is the description of the matrix calculation method that is the basis of the present invention.

  Using the matrix calculated in this manner, a matrix calculation unit 436 described later generates a spectral image signal from the color image signal.

  Since the signal corresponding to the narrowband bandpass filters F1, F2, and F3 calculated (from the RGB wideband bandpass filters) by the signal processing by the matrix calculation unit 436 and the like as described above becomes a spectral image signal, it will be described later. In this embodiment, F1, F2, and F3 are used as spectral image signals.

  In addition, F1, F2, and F3 as spectral image signals correspond to narrow band-pass filters generated by electrical signal processing. A band-band pal filter may be used.

(Correction method)
Next, a correction method for obtaining a more accurate spectral image signal will be described.

  In the above description of the matrix calculation method, the light beam received by a solid-state imaging device such as a CCD is exactly white light (all wavelength intensities are the same in the visible range), and is applied accurately. . That is, the approximation is optimal when the RGB outputs are the same.

  However, under actual endoscopic observation, the light beam to be illuminated (the light beam from the light source) is not completely white light, and the reflection spectrum of the living body is not uniform, so the light beam received by the solid-state imaging device is not white light (color) Are not the same).

  Therefore, in an actual process, in order to solve the proposition shown in the expression (3) more accurately, it is desirable to consider the spectral characteristics of illumination light and the reflection characteristics of a living body in addition to RGB color sensitivity characteristics.

  Here, the color sensitivity characteristics are respectively R (λ), G (λ), and B (λ), an example of the spectral characteristic of the illumination light is S (λ), and an example of the reflection characteristic of the living body is H (λ). . Note that the spectral characteristics of the illumination light and the reflection characteristics of the living body do not necessarily have to be the characteristics of the inspection apparatus and the subject, and may be general characteristics acquired in advance, for example.

Using these coefficients, the correction coefficients k _R · k _G · k _B are
[Equation 6]
k _R = (∫S (λ) × H (λ) × R (λ) dλ) ⁻¹
k _G = (∫S (λ) × H (λ) × G (λ) dλ) ⁻¹
k _B = (∫S (λ) × H (λ) × B (λ) dλ) ⁻¹ (6)
Given in. When the sensitivity correction matrix is “K”, it is given as follows.

従って、係数マトリックス「Ａ」については、（５）式に（７）式の補正を加えて、以下のようになる。 [Equation 7]

Accordingly, the coefficient matrix “A” is as follows after adding the correction of the equation (7) to the equation (5).

また、実際に最適化を行う場合、目標とするフィルタの分光感度特性（図１中のＦ1・Ｆ2・Ｆ3）が負のときは画像表示上では０となる（つまりフィルタの分光感度特性のうち正の感度を有する部分のみ使用される）ことを利用し、最適化された感度分布の一部が負になることも許容されることが付加される。電子内視鏡装置は、ブロードな分光感度特性から狭帯域な分光感度特性を生成するためには、図１に示すように目標とするＦ1・Ｆ2・Ｆ3の特性に、負の感度特性を付加することで、感度を有する帯域を近似した成分を生成することができる。 [Equation 8]

When the optimization is actually performed, when the spectral sensitivity characteristics of the target filter (F1, F2, and F3 in FIG. 1) are negative, it becomes 0 on the image display (that is, out of the spectral sensitivity characteristics of the filter). It is added that only part of the optimized sensitivity distribution is allowed to be negative. In order to generate a narrow-band spectral sensitivity characteristic from a broad spectral sensitivity characteristic, the electronic endoscope device adds a negative sensitivity characteristic to the target characteristics of F1, F2, and F3 as shown in FIG. By doing so, it is possible to generate a component approximating a sensitive band.

(S / N improvement method)
Next, a method for improving the S / N and accuracy of the generated spectral image signal will be described. This S / N improvement method solves the following problems by adding to the above-described processing method.

(I) If any of the original signals (R, G, B) in the matrix calculation method described above is saturated, the characteristics of the filters F1 to F3 in the processing method efficiently extract the structure of the portion to be observed. There is a possibility that the characteristics of the filter that can be made (ideal characteristics) may be greatly different (in R, G, and B, when the filters F1 to F3 are generated with only two signals, the two original signals are None of them must be saturated).

(Ii) Since a narrowband filter is generated from a wideband filter during conversion from a color image signal to a spectral image signal, sensitivity degradation occurs, and the component of the generated spectral image signal is also reduced. N is not good.

  As shown in FIG. 2, this S / N improvement method is performed by irradiating illumination light several times in one field (one frame) of a normal image (general color image) (for example, n times, where n is (Irradiation intensity may be changed each time. It is indicated by I0 to In in Fig. 2. This can be realized only by controlling the illumination light. .)

  Thereby, the electronic endoscope apparatus can reduce the irradiation intensity of one time, and can suppress that each of the RGB signals is saturated. Further, the image signal divided into several times is added for n sheets in the subsequent stage. Thereby, the electronic endoscope apparatus can increase the signal component and improve the S / N. In FIG. 2, integrating units 438a to 438c function as image quality adjusting units that improve S / N.

  The above is the description of the matrix calculation method that is the basis of the present invention, the correction method for obtaining an accurate spectral image signal that can be carried out together with this, and the method for improving the S / N of the generated spectral image signal. It is.

  Here, a modified example of the above-described matrix calculation method will be described.

(Modification of matrix calculation method)
The color image signals are R, G, B, and the spectral image signals to be estimated are F1, F2, F3. Strictly speaking, since the color image signals R, G, B, etc. are also functions of the positions x, y on the image, for example, R should be expressed as R (x, y), but is omitted here.

The goal is to estimate a 3 × 3 matrix “A” that calculates F1, F2, F3 from R, G, B. If “A” is estimated, F1, F2, and F3 (F ₁ , F ₂ , and F _{3 in} matrix notation) can be calculated from R, G, and B by the following equation (9).

ここで、以下のデータの表記を定義する。 [Equation 9]

Here, the following data notation is defined.

Spectral characteristics of subject: H (λ), “H” = (H (λ1), H (λ2),..., H (λn)) ^t
λ is a wavelength, and t represents transposition in matrix calculation. Similarly,
Spectral characteristics of illumination light: S (λ), “S” = (S (λ1), S (λ2),..., S (λn)) ^t
Spectral sensitivity characteristics of CCD: J (λ), “J” = (J (λ1), J (λ2),..., J (λn)) ^t
Spectral characteristics of filters for color separation: For primary colors
R (λ), “R” = (R (λ1), R (λ2),..., R (λn)) ^t
G (λ), “G” = (G (λ1), G (λ2),..., G (λn)) ^t
B (λ), “B” = (B (λ1), B (λ2),..., B (λn)) ^t
“R”, “G”, and “B” are combined into a matrix “C” as shown in the equation (10).

画像信号Ｒ，Ｇ，Ｂ、分光信号Ｆ1，Ｆ2，Ｆ3を行列で以下のように表記する。 [Equation 10]

The image signals R, G, B and the spectral signals F1, F2, F3 are expressed in matrix as follows.

画像信号「Ｐ」は次式で計算される。 [Equation 11]

The image signal “P” is calculated by the following equation.

いま、「Ｑ」を得るための色分解フィルタを「Ｆ」とすると、（１２）式同様に
［数１３］

ここで、重要な第１の仮定として、いま、被検体の分光反射率が基本的な３つの分光特性の線形和で表現できると仮定すると、（１２）式、（１３）式中の「Ｈ」は以下のように表記できる。 [Equation 12]

Assuming that the color separation filter for obtaining “Q” is “F”, [Equation 13] as in equation (12).

Here, as an important first assumption, assuming that the spectral reflectance of the subject can be expressed by a linear sum of three basic spectral characteristics, “H” in the expressions (12) and (13) "Can be expressed as follows.

ここで、「Ｄ」は３つの基本スペクトルＤ1（λ）、Ｄ2（λ）、Ｄ3（λ）を列ベクトルに持つ行列で、「Ｗ」は「Ｈ」に対するＤ1（λ）、Ｄ2（λ）、Ｄ3（λ）の寄与をあらわす重み係数である。被検体の色調がそれほど大きく変動しない場合には、この近似が成立することが知られている。 [Formula 14]

Here, “D” is a matrix having three basic spectra D1 (λ), D2 (λ), and D3 (λ) as column vectors, and “W” is D1 (λ) and D2 (λ) for “H”. , D3 (λ) is a weighting coefficient representing the contribution. It is known that this approximation is established when the color tone of the subject does not vary so much.

  Substituting equation (14) into equation (12) yields:

ここで、３×３の行列「Ｍ」は、行列「ＣＳＪＤ」の計算結果を１つにまとめた行列を示す。 [Equation 15]

Here, the 3 × 3 matrix “M” indicates a matrix in which the calculation results of the matrix “CSJD” are combined.

  Similarly, the following equation is obtained by substituting the equation (14) into the equation (13).

同じく、「Ｍ’」は、行列「ＦＳＪＤ」の計算結果を１つにまとめた行列を示す。 [Equation 16]

Similarly, “M ′” indicates a matrix in which the calculation results of the matrix “FSJD” are combined into one.

  Eventually, “W” is eliminated from the equations (15) and (16), and the following equation is obtained.

「Ｍ^−１」は行列「Ｍ」の逆行列を示す。結局、「Ｍ’Ｍ^−１」は３×３の行列となり、推定目標の行列「Ａ」となる。 [Equation 17]

“M ⁻¹ ” indicates an inverse matrix of the matrix “M”. Eventually, “M′M ⁻¹ ” becomes a 3 × 3 matrix, and becomes the estimation target matrix “A”.

色分解用のバンドパスが完全なバンドパスでなく、他の帯域にも感度を持つ場合も考慮して、この仮定が成立する場合、（１５）式、（１６）式における「Ｗ」を上記「Ｈ」と考えれば、結局（１７）式と同様な行列が推定できる。 Here, as an important second assumption, when color separation is performed using a bandpass filter, it is assumed that the spectral characteristic of the subject in the band can be approximated by one numerical value. That is,
[Equation 18]

In consideration of the case where the bandpass for color separation is not a complete bandpass and has sensitivity in other bands as well, when this assumption is satisfied, “W” in the expressions (15) and (16) is Considering “H”, a matrix similar to the equation (17) can be estimated after all.

  Next, a specific configuration of the electronic endoscope apparatus according to the first embodiment of the biological observation apparatus of the present invention will be described with reference to FIG. In addition, you may make it the same structure also in the other Example mentioned later.

As shown in FIG. 3, the electronic endoscope apparatus 100 includes an electronic endoscope (abbreviated as endoscope) 101, an endoscope apparatus body 105, and a display monitor 106 as a display apparatus. The endoscope 101 is provided on the opposite side of the insertion portion 102 inserted into the body of the subject, the distal end portion 103 provided at the distal end of the insertion portion 102, and the distal end side of the insertion portion 102, It is mainly composed of an angle operation unit 104 for operating or instructing a bending operation or the like on the distal end portion 103 side.
An image of the inside of the subject acquired by the endoscope 101 is subjected to predetermined signal processing in the endoscope apparatus main body 105, and the processed image is displayed on the display monitor 106.

Next, the endoscope apparatus main body 105 will be described in detail with reference to FIG. FIG. 4 is a block diagram of the electronic endoscope apparatus 100.
As shown in FIG. 4, the endoscope apparatus main body 105 includes a light source section 41 as an illuminating section that mainly generates illumination light, a control section 42 that controls the light source section 41 and the main body processing apparatus 43 described below. The main body processing device 43 performs signal processing for generating an image and signal processing for generating a spectral image. The control unit 42 and the main body processing device 43 constitute a signal processing control unit that controls the operation of the CDD 21 as the light source unit 41 and / or the imaging unit and outputs an imaging signal to the display monitor 106 that is a display device. .
In this embodiment, the endoscope apparatus main body 105, which is a single unit, is described as having a light source unit 41 and a main body processing apparatus 43 that performs image processing and the like. You may be comprised so that connection and removal are possible. In addition, the living body observation apparatus can be configured by the endoscope 101, the light source unit 41, and the main body processing apparatus 43, but is not limited thereto. For example, the biological observation apparatus can be configured by the light source unit 41 and the main body processing apparatus 43, or can be configured by only the main body processing apparatus 43.
The light source unit 41 is connected to the control unit 42 and the endoscope 101. Based on the signal from the control unit 42, the light source unit 41 emits white light (including a case where the light is not perfect white light) with a predetermined light amount. The light source unit 41 includes a lamp 15 as a white light source, a chopper 16 for adjusting the light amount, and a chopper driving unit 17 for driving the chopper 16.

  As shown in FIG. 5, the chopper 16 has a configuration in which a notch portion having a predetermined length in the circumferential direction is provided in a disk-like structure having a predetermined radius r and having a center at a point 17 a. The center point 17a is connected to a rotating shaft provided in the chopper driving unit 17. That is, the chopper 16 performs rotational movement around the center point 17a. In addition, a plurality of notches are provided for each predetermined radius. In this figure, the notch has a maximum length = 2πr × θ0 degrees / 360 degrees and a width = r0−ra between the radius r0 and the radius ra. Similarly, the maximum length = 2πra × 2θ1 degrees / 360 degrees between the radius ra and the radius rb, the width = ra−rb, and the maximum length = 2πrb × 2θ2 between the radius rb and the radius rc. Degree / 360 degrees and width = rb−rc (respective radii are r0> ra> rb> rc).

  In addition, the length and width of the notch in the chopper 16 are examples, and are not limited to the present embodiment.

  Further, the chopper 16 has a protrusion 160a extending in the radial direction substantially at the center of the notch. The control unit 42 switches the frame when the light is blocked by the projection 160a, thereby minimizing the interval between the light irradiated one frame before and after the frame, and blurring due to the movement of the subject. Minimize.

  Further, the chopper driving unit 17 is configured to be movable in the direction with respect to the lamp 15 as indicated by an arrow in FIG.

  That is, the control unit 42 can change the distance R between the rotation center 17a of the chopper 16 shown in FIG. 5 and the luminous flux from the lamp (shown by a dotted circle). For example, in the state shown in FIG. 5, since the distance R is quite small, the amount of illumination light is small. By increasing the distance R (the chopper driving unit 17 is moved away from the lamp 15), the cutout portion through which the light beam can pass becomes longer, so the irradiation time becomes longer, and the control unit 42 can increase the amount of illumination light. .

  As described above, in the electronic endoscope apparatus, there is a possibility that the newly generated spectral image may not be sufficient as the S / N, and one of the RGB signals necessary for generating the spectral image is saturated. In such a case, the correct calculation is not performed, and it is necessary to control the amount of illumination light. The light amount adjustment is performed by the chopper 16 and the chopper driving unit 17.

  The endoscope 101 detachably connected to the light source unit 41 via the connector 11 is disposed at the objective lens 19 that connects the optical image to the distal end portion 103 and the imaging position thereof, and is a solid state such as a CCD that performs photoelectric conversion. An imaging device 21 (hereinafter simply referred to as a CCD) is provided. The CCD in this embodiment is of a single plate type (CCD used for a simultaneous electronic endoscope) and has a primary color transmission filter (abbreviated as color filter). FIG. 6 shows an arrangement of color filters arranged on the CDD imaging surface. FIG. 7 shows the spectral sensitivity characteristics of RGB in the color filter of FIG.

  As shown in FIG. 7, the RGB color filters have spectral characteristics that transmit the R, G, and B wavelength regions in the visible region over a wide band.

  As shown in FIG. 4, the insertion unit 102 transmits the light guide 14 that guides the light emitted from the light source unit 41 to the distal end portion 103 and the image of the subject obtained by the CCD to the main body processing device 43. A signal line for performing the treatment, a forceps channel 28 for performing the treatment, and the like. A forceps port 29 for inserting forceps into the forceps channel 28 is provided in the vicinity of the operation unit 104.

    In addition, the main body processing device 43 is connected to the endoscope 101 via the connector 11, similarly to the light source unit 41. The main body processing device 43 includes a CCD drive circuit 431 for driving the CCD 21.

The main body processing device 43 has a luminance signal processing system that generates a luminance signal as a signal circuit system for obtaining a normal image, and a color signal processing system that generates a broadband color signal.
The luminance signal processing system includes a contour correction unit 432 that is connected to the CCD 21 and performs contour correction, and a luminance signal processing unit 434 that generates a luminance signal from data corrected by the contour correction unit 432.

  The color signal processing system is connected to the CCD 21 and samples the signal obtained by the CCD 21 and generates a RGB signal as a broadband color signal (or color image signal). 433a to 433c, and a color signal processing unit 435 that is connected to the output terminals of the S / H circuits 433a to 433c and performs processing on color signals.

Further, the main body processing device 43 is provided with a normal image generation unit 437 that generates one color normal image as a color image captured in the visible region from the output of the luminance signal processing system and the color signal processing system. Then, a Y signal, an RY signal, and a BY signal are sent to the display monitor 106 from the normal image generation unit 437 via the switching unit 439 as color normal image signals.
On the other hand, as a signal circuit system as a spectral image generation means for obtaining a spectral image, a matrix calculation unit 436 that generates spectral image signals F1, F2, and F3 from output signals of the S / H circuits 433a to 433c that generate the RGB signals. Have. The matrix calculation unit 436 performs a predetermined matrix calculation on the RGB signals.

  Matrix calculation refers to a process of performing addition processing between color image signals using calculation coefficients corresponding to a coefficient matrix, and multiplying the matrix obtained by the above-described matrix calculation method (or a modified example thereof). . The matrix calculation unit 436 generates narrowband spectral image signals F1, F2, and F3 from the R, G, and B color image signals.

In this embodiment, a method using electronic circuit processing (processing by hardware using an electronic circuit) will be described as the matrix calculation method. However, as in the embodiments described later, numerical data processing (program A method using software processing using Moreover, when implementing, it is also possible to combine these.
FIG. 8 shows a circuit diagram of the matrix calculation unit 436. The RGB signals are the resistance groups 31-1a, 31-2a, 31-3a to 31-1c, 31-2c, 31-3c and multiplexers 33-1a, 33-2a, 33-3a to 33-1c, 33-33, respectively. The signals are input to the amplifiers 32a to 32c via 2c and 33-3c.

  The resistor groups 31-1a, 31-2a,..., 31-3c are composed of resistors r1, r2,..., Rn having different resistance values (in FIG. 8, only some of the symbols r1, r2,. Is shown). Then, one resistor is selected by each of the multiplexers 33-1a, 33-2a,..., 33-3c.

  These multiplexers 33-1a, 33-2a,..., 33-3c are operated by a switching operation or selection operation by a user on an operation panel 441 (see FIG. 4) constituting a coefficient setting switching means provided on the front panel, for example. The resistances selected in the resistance groups 31-1a, 31-2a,..., 31-3c are determined via the coefficient control unit 442. The operation panel 441 operated by the user also has a function of interface means for the user to perform switching (selection) of the observation mode, confirmation of the state of the observation mode, etc. in the main body processing device 43 that performs signal processing.

  The observation mode (observation image mode) is selected by selecting the image displayed on the display monitor 106 and the main body processing apparatus so that at least a video signal (image signal) corresponding to the image is generated by signal processing. 43 includes the function of the signal processing system.

  That is, when the color normal image (also simply referred to as normal image) observation mode is selected as the observation mode, the switching unit 439 is switched so that the normal image is displayed on the display monitor 106, and The normal image processing system is activated so that a normal image signal corresponding to the normal image is generated. The normal image processing system in this case corresponds to the contour correction unit 432, the luminance signal processing unit 434, the color signal processing unit 435, and the normal image generation unit 437 in FIG.

  When the spectral image observation mode is selected as the observation mode, the switching unit 439 is switched so that the spectral image is displayed on the display monitor 106, and the spectral image signal corresponding to the spectral image is displayed. So that the spectral image processing system is activated. The spectral image processing system in this case corresponds to the coefficient control unit 442, the LUT 443, the matrix calculation unit 436, the integration units 438a to 438c, and the color adjustment unit 440 in FIG.

  The CCD drive circuit 431 and the S / H circuits 433a to 433c are maintained in the operation state in common in both observation modes. In response to the selection of the observation mode, the control unit 42 may perform control so that the signal processing system corresponding to the selected observation mode is in an operating state. Alternatively, both signal processing systems may always be maintained in the operating state.

  In this case, the operation for selecting the observation mode has the same result as the selection of the image (observation image) displayed on the display monitor 106. However, as will be described later, it may be better to change the parameter value (or target value) when performing the light amount control with the illumination light amount as the target value in conjunction with the selection (switching) of the observation mode.

The user can also perform a selection operation using the endoscope switch 141 provided in the operation unit of the endoscope 101. The endoscope switch 141 also forms coefficient setting switching means for switching coefficients, and interface means for the user to switch (select) the observation mode.
The operation panel 441 and the like are provided with a plurality of selection switches (or switching buttons) 441a corresponding to, for example, the type of the subject to be observed, the observation site, the tissue type of the living tissue (the morphological type of the tissue), and the like. is there. When the user operates the selection switch 441a, the selection switch 441a outputs an instruction signal corresponding to the type of the subject, the observation site, the tissue type of the living tissue, and the like to the coefficient control unit 442.
As shown in FIG. 4, the coefficient control unit 442 is connected to an LUT 443 as a calculation coefficient storage unit that stores calculation coefficients (simply abbreviated as coefficients) for determining matrix calculation characteristics or matrix calculation results of the matrix calculation unit 436. ing. Then, the coefficient control unit 442 reads a coefficient corresponding to the type of the subject from the LUT 443 in accordance with an instruction signal from the selection switch 441 a of the operation panel 441 and sends the coefficient to the matrix calculation unit 436.

  That is, the LUT 443 stores a plurality of coefficients 443a corresponding to the type of spectral characteristics (spectral reflectance characteristics) of the subject, more specifically, the type of spectral reflectance characteristics of the mucosal tissue of the living body as the subject. ing. That is, the coefficient 443a is a biometric coefficient corresponding to the type of mucosal tissue of the living body.

The matrix calculation unit 436 performs matrix calculation using the coefficient 443a read from the LUT 443 and sent. In this way, even when the type of subject, the tissue type of the living tissue, and the like are different, the optical narrowband image signal or spectral image actually captured (acquired) using the optical narrowband bandpass filter Compared to the case of a signal, a reduction in accuracy is suppressed, and an operation of generating a spectral image signal (pseudo-optical by signal processing) is enabled.
As described above, in this embodiment, the matrix calculation unit 436 is connected to the LUT 443 that stores a plurality of coefficients 443a via the coefficient control unit 442. Then, the user can change and set (switch) the coefficients that are actually used for matrix calculation of the matrix calculation unit 436 via the coefficient control unit 442 by operating the operation panel 441 or the like. The characteristics of the image signals F1, F2, and F3 can be changed and set. That is, the coefficient control unit 442 and the LUT 443 have a function of a characteristic change setting unit that changes and sets the characteristic of the spectral image signal generated by the spectral image signal generation unit.

  The outputs of the matrix calculation unit 436 are input to the integration units 438a to 438c, respectively, and integration operations are performed by the integration units 438a to 438c to generate spectral image signals ΣF1 to ΣF3. The spectral image signals ΣF1 to ΣF3 are input to the color adjustment unit 440, and the color adjustment unit 440 performs a color adjustment operation with a configuration described later. The color adjustment unit 440 generates spectral channel image signals Rnbi, Gnbi, and Bnbi as spectral image signals that have been color-tone adjusted from the spectral image signals ΣF1 to ΣF3.

  Then, the color image signal (also referred to as a biological signal) from the normal image generation unit 437 or the spectral channel image signals Rnbi, Gnbi, and Bnbi from the color adjustment unit 440 are sent to the R of the display monitor 106 via the switching unit 439. Channels, G-channels, and B-channels (sometimes abbreviated as Rch, Gch, and Bch) are output and displayed on the display monitor 106 in R, G, and B display colors. Therefore, the color adjustment unit 440 has a function of display color conversion means for converting the display color when the spectral image signals ΣF1 to ΣF3 are displayed in pseudo color on the display monitor 106. The display color conversion means has a function of display color adjustment or color adjustment means for adjusting the display color by performing a change setting such as switching a coefficient used when converting the display color. Further supplementary explanation regarding the color adjustment unit 440 is as follows.

  As described above, the spectral image signals ΣF 1 to ΣF 3 are subjected to (display) color adjustment processing including display color conversion by the color adjustment unit 440 to become spectral channel image signals Rnbi, Gnbi, Bnbi, and the R channel of the display monitor 106. , G channel and B channel. When the spectral image signals ΣF1 to ΣF3 are output to the R channel, the G channel, and the B channel of the display monitor without any (display) color conversion (display colors are assigned), the color tone is fixed, and the user changes the color tone. Cannot be selected or changed.

In this embodiment, by providing the color adjusting means including color conversion as described above, pseudo color display can be performed with a color tone desired by the user. In addition, by performing color conversion or color adjustment, pseudo color display can be performed in a state where it is easier to visually recognize. As can be seen from the above description, the spectral channel image signals Rnbi, Gnbi, and Bnbi are used to clearly indicate that they are output to the R channel, G channel, and B channel of the display monitor 106, respectively. For this reason, these signals are collectively referred to as spectral image signals. When focusing on pseudo color display on the monitor side as in Example 7 described later, the spectral channel image signals Rnbi, Gnbi, and Bnbi can also be referred to as color channel image signals. The configuration of the color adjustment unit 440 will be described later.
The color adjustment unit 440 is connected to an operation panel 441 having a function as a display color change setting unit or an interface unit, an endoscope switch 141, and the like. The operation panel 441, the endoscope switch 141, and the like allow a user or the like to perform a display color change setting operation (more specifically, a coefficient switching setting operation) for color adjustment. As will be described later, the coefficients of the 3 × 3 matrix circuit 61 that performs display color conversion can be switched by a signal from the operation panel 441 or the like via the coefficient changing circuit 64 (see FIG. 21) constituting the color adjusting unit 440. .
Note that the switching unit 439 switches between a normal image and a spectral image, and can also switch between spectral images. That is, a user such as a surgeon selects (switches) the signal that has been selected and operated by selecting a signal to be output to the display monitor 106 from the normal image signal and the spectral channel image signals Rnbi, Gnbi, and Bnbi. To the display monitor 106.

The switching unit 439 is connected to the operation panel 441 and the endoscope switch 141, and the user can easily switch or select the normal image and the spectral image by operating these. Therefore, according to the present embodiment, operability can be improved. As shown in FIG. 4, the instruction input from the keyboard 451 is input to the control unit 42. When the instruction input is a switching instruction, the control unit 42 performs switching control of the switching unit 439 in response to the switching instruction.
Further, any two or more images may be displayed on the display monitor 106 at the same time. A configuration related to this will be described later with reference to FIG.
In particular, when a normal image and a spectral channel image (also referred to as a spectral image) can be displayed at the same time, the normal image and the spectral image that are generally observed can be easily compared with each other ( The characteristics of normal images are easy to observe because the color tone is close to that of normal visual observation, and the characteristics of spectroscopic images can be observed with certain blood vessels that cannot be observed with normal images. Can be very useful diagnostically.

Next, the operation of the electronic endoscope apparatus 100 according to the present embodiment will be described in detail with reference to FIG.
In the following, the operation when observing a normal image will be described first, and the operation when observing a spectral image will be described later.
First, the operation of the light source unit 41 will be described. Based on the control signal from the control unit 42, the chopper driving unit 17 is set to a predetermined position and rotates the chopper 16. The light beam from the lamp 15 passes through the notch portion of the chopper 16 and is a light guide 14 that is an optical fiber bundle provided in the connector 11 at the connection portion of the endoscope 101 and the light source portion 41 by a condenser lens. Condensed at the incident end of.

  The condensed light flux passes through the light guide 14 and is irradiated into the body of the subject from an illumination optical system (not shown) provided at the distal end portion 103. The irradiated light beam is reflected in the subject, and signals are collected for each color filter shown in FIG. 6 in the CCD 21 provided with the color filter via the objective lens 19. Signals (imaging signals) collected for each color filter by the CCD 21 are input in parallel to the luminance signal processing system and the color signal processing system.

  The luminance signal-based contour correction unit 432 adds the signals collected for each color filter for each pixel and inputs them. After contour correction, the signals are input to the luminance signal processing unit 434. In the luminance signal processing unit 434, a luminance signal is generated and input to the normal image generating unit 437.

On the other hand, the signals collected by the color filters by the CCD 21 are input to the S / H circuits 433a to 433c for each filter, and R, G, and B signals are generated as a plurality of broadband color signals. Further, the R, G, and B signals are subjected to signal processing on the color signals in the color signal processing unit 435, and then, in the normal image generation unit 437, Y signals as color image signals from the luminance signals and color signals, R -Y signal and BY signal are generated, and the normal image of the subject is displayed in color on the display monitor 106 via the switching unit 439.
As shown in FIG. 4, the output terminal of the switching unit 439 is made common to the output signal from the normal image generation unit 437 and the output signal from the color adjustment unit 440, and the R channel and G of the display monitor 106. It may be configured to input to the channel and the B channel. In the case of a configuration in which the output terminals are shared, the switching unit 439 converts the Y signal, the RY signal, and the BY signal that are output signals from the normal image generation unit 437 into R, G, and B signals. A conversion circuit 439a (see FIG. 4) to be used may be incorporated.

Without incorporating this conversion circuit 439a, the output signal from the normal image generation unit 437 is at the Y / color difference signal input terminal of the display monitor 106, and the output signal from the color adjustment unit 440 is at the display monitor 106. It may be configured to input to the R channel, G channel, and B channel. In the following description, for the sake of simplification, when the output signal from the normal image generation unit 437 is output from the switching unit 439, the display monitor 106 passes through the common R channel, G channel, and B channel. This will be described in the case of input to
Next, the operation when observing a spectral image will be described. In addition, what performs the same operation | movement as normal image observation is abbreviate | omitted here.
The operator gives an instruction to observe the spectral image from the normal image by operating the endoscope switch 141, the keyboard 451, and the like connected to the endoscope apparatus main body 105. At this time, the control unit 42 changes the control state of the light source unit 41 and the main body processing device 43.

Specifically, the control unit 42 changes the amount of light emitted from the light source unit 41 as necessary. As described above, since it is not desirable that the output signal from the CCD 21 is saturated, the amount of illumination light is made smaller than that during normal image observation. Further, the control unit 42 can control the amount of light so that the output signal from the CCD 21 does not saturate, and can also change the amount of illumination light within a range where it is not saturated.
As an example of changing the control content to the main body processing device 43 by the control unit 42, the signal output from the switching unit 439 is changed from the output of the normal image generation unit 437 to the output of the color adjustment unit 440, that is, the spectral channel image signal Rnbi. , Gnbi, Bnbi.

  The outputs of the S / H circuits 433a to 433c are input to the matrix calculation unit 436, and the matrix calculation unit 436 performs amplification and addition processing, thereby generating narrow-band spectral image signals F1, F2, and F3. The These spectral image signals F1, F2, and F3 are output to the integrators 438a to 438c in accordance with the respective bands.

Even when the amount of illumination light is reduced by the chopper 16, the signal intensity can be increased as shown in FIG. 2 by storing and integrating by the integrating units 438 a to 438 c. Further, the integrated spectral image signals ΣF1, ΣF2, and ΣF3 with improved S / N can be obtained from the spectral image signals F1, F2, and F3 by the integrating units 438a to 438c, respectively.
Hereinafter, specific matrix processing of the matrix calculation unit 436 in the present embodiment will be described. In this embodiment, from the spectral sensitivity characteristics of the RGB color filter indicated by the solid line in FIG. 7, the ideal narrow-band bandpass filters F1 to F3 (in this case, the respective transmission wavelength regions are indicated by F1). : 590 nm to 620 nm, F2: 520 nm to 560 nm, F3: 400 nm to 440 nm), when trying to create a bandpass filter (hereinafter referred to as a pseudo bandpass filter), Depending on what is shown in the equation, the following matrix is optimal.

更に、（６）式及び（７）式に示した内容により補正を行うと、以下の補正係数を得る。
［数２０］

なお、（６）式に示す光源のスペクトルＳ（λ）は図９に示すものであり、（７）式に示す注目する生体の反射スペクトルＨ（λ）は図１０に示すものである、という先見情報を使用している。 [Equation 19]

Further, when correction is performed according to the contents shown in the equations (6) and (7), the following correction coefficients are obtained.
[Equation 20]

The spectrum S (λ) of the light source shown in the equation (6) is as shown in FIG. 9, and the reflection spectrum H (λ) of the target organism shown in the equation (7) is as shown in FIG. Use foresight information.

このマトリックス演算を行うことにより擬似フィルタ特性（図７には擬似Ｆ1乃至擬似Ｆ3の特性として示されている）が得られる。即ち、上述のマトリックス処理は、カラー画像信号に、上述のようにして予め生成された擬似バンドパスフィルタ（即ちマトリックス）を用いて、分光画像信号を作成するものである。
この擬似フィルタ特性を用いて生成された内視鏡画像の模式的な例を以下に説明する。 Accordingly, the processing performed by the matrix calculation unit 436 is mathematically equivalent to the following matrix calculation.
[Equation 21]

By performing this matrix operation, pseudo filter characteristics (shown as pseudo F1 to pseudo F3 characteristics in FIG. 7) are obtained. That is, the matrix processing described above creates a spectral image signal using a pseudo bandpass filter (that is, a matrix) generated in advance as described above for a color image signal.
A schematic example of an endoscopic image generated using this pseudo filter characteristic will be described below.

As shown in FIG. 11, the body cavity tissue 51 often has a distribution structure of absorbers such as blood vessels that differ in the depth direction. A large number of capillaries 52 are mainly distributed in the vicinity of the mucous membrane surface layer, and blood vessels 53 that are thicker than capillaries are distributed in the middle layer deeper than this layer, and thicker blood vessels 54 are further distributed in the deep layer. become.
On the other hand, the depth of light in the depth direction with respect to the tissue 51 in the body cavity depends on the wavelength of the light. As shown in FIG. 12, when the illumination light including the visible region is light having a short wavelength such as blue (B), the light can reach only near the surface layer due to the absorption and scattering characteristics in the living tissue. Instead, light that has been absorbed and scattered in the depth range up to that point is observed.

  In the case of green (G) light, which has a wavelength longer than that of blue (B) light, it reaches deeper than the range where blue (B) light deepens, absorbs and scatters within that range, and exits from the surface. Light is observed. Still further, red (R) light having a wavelength longer than that of green (G) light reaches a deeper range.

The RGB light during normal observation of the body cavity tissue 51, as shown in FIG.
(1) Band images having shallow layer and middle layer tissue information including a lot of tissue information in the shallow layer as shown in FIG.
(2) In addition, the image signal picked up by the CCD 21 with the G-band light is picked up with a shallow layer image including a lot of tissue information in the middle layer and a band image having the middle layer tissue information as shown in FIG.
(3) Further, a band image having middle layer and deep layer tissue information including a lot of tissue information in the deep layer as shown in FIG.

The endoscope apparatus main body 105 performs signal processing on these RGB imaging signals, whereby an endoscopic image having a desired or natural color reproduction can be obtained as an endoscopic image.
The matrix processing in the matrix calculation unit 436 is to create a spectral image signal using a matrix of pseudo bandpass filter characteristics generated in advance as described above for the color image signal.

  Further, the user operates the operation panel 441 and the like to read out the coefficient 443a stored in the LUT 443 through the coefficient control unit 442 and change and set the matrix operation characteristic in the matrix operation unit 436, thereby the pseudo band. The path filter characteristics can be changed.

  For example, by changing the coefficient 443a, the pseudo bandpass filter characteristic generated by the matrix calculation unit 436 is generated with high accuracy on the shallow layer side, and is set to a characteristic that does not generate other pseudo bandpass filter characteristics. You can also That is, the band wavelength (center) value of the pseudo bandpass filter characteristic generated by the coefficient 443a can be set corresponding to the feature amount.

  Accordingly, the coefficient 443a has a function of a biometric feature quantity coefficient for generating a spectral image signal so as to emphasize a feature quantity such as a blood vessel structure distributed at a depth from the surface of the biological tissue.

  That is, the spectral image signal generation means and its characteristic change setting unit in this embodiment mainly have two major advantages as follows.

  The user can change the precision (including switching) to use an appropriate coefficient (as a biological coefficient) 443a in accordance with the spectral reflection characteristics of the living body, so that the biological tissue with different spectral reflection characteristics can be accurately set. A good spectral image signal can be obtained.

  When it is desired to observe a biological part that is easily observed (observed) with a specific narrowband wavelength (N), the user emphasizes the spectral image signal corresponding to the narrowband wavelength (N). By changing and setting the coefficient 443a to be generated (or suppressing other spectral image signals having a narrow band wavelength), the living body portion can be observed with a good S / N.

On the other hand, spectral image signals F1 to F3 are obtained by using pseudo bandpass filters F1 to F3 having discrete and narrow-band spectral characteristics that can extract desired deep tissue information as shown in FIG. As shown in FIG. 17, the pseudo bandpass filters F1 to F3 are not overlapped with each other.
(4) A band image having tissue information in a shallow layer as shown in FIG. 18 is captured in the spectral image signal F3 by the pseudo bandpass filter F3,
(5) A band image having tissue information in the middle layer as shown in FIG. 19 is captured in the spectral image signal F2 by the pseudo bandpass filter F2, and (6) the spectral image signal F1 by the pseudo bandpass filter F1 A band image having tissue information in the deep layer as shown in FIG. 20 is captured.

  Next, with respect to the spectral image signals ΣF1 to ΣF3 obtained by integrating the spectral image signals F1 to F3 thus obtained, the color adjusting unit 440 converts the spectral image signal F1 into the spectral channel image signal Rnbi and the spectral image signal F2. Are assigned to the spectral channel image signal Gnbi, and the spectral image signal F3 is assigned to the spectral channel image signal Bnbi. The spectral channel image signals Rnbi, Gnbi, and Bnbi are output to the R, G, and B channels Rch, Gch, and Bch of the display monitor 106 via the switching unit 439, respectively.

As shown in FIG. 21, the color adjustment unit 440 includes a 3 × 3 matrix circuit 61 as a display color conversion unit and three sets of LUTs 62a, 62b, 62c provided before and after the 3 × 3 matrix circuit 61. 63a, 63b, 63c, and a coefficient changing circuit 64 as display color change setting means for changing the table data of the LUTs 62a, 62b, 62c, 63a, 63b, 63c and the matrix coefficient of the 3 × 3 matrix circuit 61. The color conversion processing circuit 440a is configured.
The spectral image signals F1 to F3 input to the color conversion processing circuit 440a are subjected to inverse γ correction, nonlinear contrast conversion, and the like by the LUTs 62a, 62b, and 62c for each band data.

Next, after color conversion is performed in the 3 × 3 matrix circuit 61, γ correction and appropriate gradation conversion processing are performed in the subsequent LUTs 63a, 63b, and 63c.
The table data of these LUTs 62a, 62b, 62c, 63a, 63b, 63c and the matrix coefficients of the 3 × 3 matrix circuit 61 can be changed by a coefficient changing circuit 64 that changes coefficients. In the coefficient changing circuit 64, a plurality of types of matrix coefficients 64a used when performing a matrix operation by the 3 × 3 matrix circuit 61 are stored as color conversion (color adjustment) coefficients.

  The 3 × 3 matrix circuit 61 performs color conversion corresponding to the used matrix coefficient 64 a by performing matrix calculation using the matrix coefficient 64 a selected via the coefficient changing circuit 64.

  The matrix coefficient change by the coefficient change circuit 64 is performed by a coefficient setting switch (or color tone change setting switch) 141b in the operation panel 441 or the endoscope switch 141 provided in the operation unit of the endoscope 101, for example. Based on the control signal or switching signal from (see FIG. 4).

  In addition, the matrix coefficient 64a in the coefficient changing circuit 64 includes, for example, a blood vessel matrix coefficient 64b that can display the blood vessel structure in a color tone that can be easily identified as a characteristic amount of the living body as described below. . The user can select the blood vessel matrix coefficient 64b from the coefficient changing circuit 64 by operating the coefficient setting switch 141b.

  In addition to changing the matrix coefficient 64a used in the 3 × 3 matrix circuit 61 to the coefficient changing circuit 64 by operating the coefficient setting switch 141b, the user can change the LUTs 62a, 62b, 62c, 63a, A control signal for changing the table data 63b and 63c can be output.

  Upon receiving the control signal, the coefficient changing circuit 64 calls appropriate data from data such as a plurality of types of matrix coefficients 64a stored in the color adjustment unit 440 in advance, and rewrites the current circuit coefficient with the data.

  Next, specific color conversion processing contents will be described. Formula (22) shows an example of a color conversion formula.

この式（２２）による処理は、分光チャンネル画像信号Ｒnbi、Ｇnbi、Ｂnbi（表示モニタａ１０６での表示で示すと、Ｒチャンネル、Ｇチャンネル、Ｂチャンネル）に分光画像信号Ｆ1乃至Ｆ3を波長の短い順に割り当てる色変換である。
これら分光チャンネル画像信号Ｒnbi、Ｇnbi、Ｂnbiによるカラー画像で観察した場合、例えぱ図２２に示すような画像となる。太い血管が深い位置にあり、分光画像信号Ｆ3が反映され、表示色としては青色系のパターンとして示される。中層付近にある血管網は分光画像信号Ｆ2が強く反映されるので、表示色が赤色系のパターンで表示される。 [Equation 22]

The processing according to the equation (22) is performed by dividing the spectral image signals F1 to F3 into the spectral channel image signals Rnbi, Gnbi, and Bnbi (indicated by display on the display monitor a106, the R channel, the G channel, and the B channel) in ascending order of wavelength. Color conversion to be assigned.
When observed with a color image by these spectral channel image signals Rnbi, Gnbi, and Bnbi, an image as shown in FIG. 22, for example, is obtained. The thick blood vessel is in a deep position, the spectral image signal F3 is reflected, and the display color is shown as a blue pattern. Since the spectral image signal F2 is strongly reflected in the vascular network in the vicinity of the middle layer, the display color is displayed in a red pattern.

In addition, those existing in the vicinity of the mucosal surface in the vascular network are expressed as a pattern whose display color is yellow.
In particular, this pattern change near the mucosal surface is important for early differential detection and diagnosis of lesions. However, yellow patterns tend to have low contrast with the background mucosa and low visibility.
Therefore, in order to reproduce the pattern near the mucosal surface with clearer visibility, the conversion shown in Expression (23) is effective.

この式（２３）による処理は、分光画像信号Ｆ1をある一定の比率で分光画像信号Ｆ2に混合し、生成されたデータを新たに分光Ｇチャンネル画像信号Ｇnbiとする変換例である。この変換を採用すると、血管網などの吸収散乱体が深さ位置で異なることをより明確化することが可能となる。 したがって、ユーザは、係数変更回路６４を介してマトリックス係数６４ａを調整することで、ユーザは好みの表示効果が得られるように表示色を調整することが可能となる。 [Equation 23]

The processing according to the equation (23) is a conversion example in which the spectral image signal F1 is mixed with the spectral image signal F2 at a certain ratio and the generated data is newly used as the spectral G channel image signal Gnbi. When this conversion is adopted, it becomes possible to further clarify that absorption scatterers such as a vascular network are different in depth positions. Therefore, the user can adjust the display color so that a desired display effect can be obtained by adjusting the matrix coefficient 64a via the coefficient changing circuit 64.

  Such an operation is as follows.

In the color adjustment unit 440 (color conversion processing circuit 440a) in conjunction with the mode switch 141c (see FIG. 4) in the endoscope switch 141 provided on the operation panel 441 or the operation unit of the endoscope 101 by the user. Then, the matrix coefficient 64a is set to a default value from the through operation.
The through operation here means a state in which the 3 × 3 matrix circuit 61 is mounted with a unit matrix, and the LUTs 62a, 62b, 62c, 63a, 63b, and 63c are mounted with non-conversion tables. For the default value, for example, set values of ω _G = 0.2 and ω _B = 0.8 are given as the matrix coefficient 64a.
Then, the user operates the operation panel 441, for example, the coefficient setting switch 141b provided in the operation switch of the endoscope 101 and provided in the endoscope switch 141, and the blood vessel matrix coefficient 64b is obtained from the coefficient changing circuit 64. select. Then, the set values ω _G = 0.2 and ω _B = 0.8 are changed to ω _G = 0.4, ω _B = 0.6, etc. as matrix coefficients of the 3 × 3 matrix circuit 61. Like that. A reverse γ correction table and a γ correction table are applied to the LUTs 62a, 62b, 62c, 63a, 63b, and 63c as necessary.

The color conversion processing circuit 440a in the present embodiment is shown as an example in which color conversion is performed by a matrix calculator composed of a 3 × 3 matrix circuit 61. However, the color conversion processing circuit 440a is not limited to this, and color conversion is performed by a numerical calculation processor (CPU) or LUT. You may comprise a conversion process means.
For example, in the above embodiment, the color conversion processing circuit 440a is shown with a configuration centered on the 3 × 3 matrix circuit 61. However, as shown in FIG. 23, the color conversion processing circuit 440a is replaced with a three-dimensional LUT 71 corresponding to each band. Even if it replaces with, the same effect can be acquired.

  In this case, the coefficient changing circuit 64 is stored in the LUT 71 based on a control signal from the coefficient setting switch 141b provided in the operation panel 441, the endoscope switch 141 of the operation unit of the endoscope 101, or the like. The operation of changing the contents of the table data 71a is performed (in FIG. 23, the table data 71a is shown in one LUT 71, but the table data 71a is similarly stored in the other LUTs 71). Then, the color conversion processing circuit 440a in FIG. 23 performs color conversion processing corresponding to the changed table data 71a.

In the table data 71a, for example, blood vessel data and biological mucosa data for displaying the blood vessel structure and the biological mucous membrane structure, etc. as biological feature quantities in a color tone that is easy to visually recognize are stored.
Note that the filter characteristics of the pseudo bandpass filters F1 to F3 are not limited to the visible light range, and as a first modification of the pseudo bandpass filters F1 to F3, the filter characteristics are discrete as shown in FIG. It may have spectral characteristics and a narrow band. In order to change to such filter characteristics, the user may change the calculation coefficient in the matrix calculation unit 436 by operating the selection switch 441a provided on the operation panel 441 or the like.

  Note that in FIG. 24 (the same applies to FIGS. 25 and 26 below), the spectral image signals F1 to F3 generated by the matrix calculation unit 436 are represented by spectral characteristics like the pseudo bandpass filter shown in FIG. .

  The filter characteristic of the first modification is that normal observation is performed by setting F3 in the near ultraviolet region and F1 in the near infrared region in order to observe the irregularities on the surface of the living body and the absorber near the extreme deep layer. It is suitable for obtaining image information that cannot be obtained by. That is, as shown in FIG. 24, optical image information on the deep side of the living body can be obtained by F1 in the near infrared region, and image information on the concavo-convex structure on the living body surface can be obtained by F3 in the near ultraviolet region. .

As a second modification of the pseudo bandpass filters F1 to F3, two pseudo bandpass filters F3a and F3b whose filter characteristics are close in the short wavelength region are used instead of the pseudo bandpass filter F2 as shown in FIG. It is also good. This is suitable for visualizing a subtle difference in the scattering characteristic rather than the absorption characteristic by utilizing the fact that the wavelength band in the vicinity reaches only near the extreme surface layer of the living body. Medically, it is assumed to be used for diagnosis and diagnosis of diseases involving disturbance of cell arrangements near the mucosal surface layer such as early cancer.
Furthermore, as a third modification of the pseudo bandpass filters F1 to F3, two pseudo-bandwidth narrowband filter characteristics of two discrete spectral characteristics from which desired layer structure information can be extracted as shown in FIG. The band pass filters F2 and F3 may be generated by the matrix calculation unit 436.

例えば、ｈ11＝１、ｈ12＝０、ｈ21＝０、ｈ22＝１．２、ｈ31＝０、ｈ32＝０．８とする。 In the case of the pseudo bandpass filters F2 and F3 in FIG. 26, the color adjustment unit 440 performs spectral channel image signal Rnbi ← spectral image signal F2 and spectral channel image signal Gnbi in colorization of an image at the time of narrow-band spectral image observation. ← Spectral image signal F3 and spectral channel image signal Bnbi ← Spectral image signal F3 are color-converted and output to RGB three channels Rch, Gch and Bch of the display monitor 106.
That is, the color adjustment unit 440 outputs the spectral image signal F2 and the spectral image signal F3 to the three RGB channels of the display monitor 106 by the following equation (24), and displays the color in RGB on the display monitor 106. Spectral image signals (Rnbi, Gnbi, Bnbi) are generated.
[Equation 24]

For example, h11 = 1, h12 = 0, h21 = 0, h22 = 1.2, h31 = 0, h32 = 0.8.

  In this case, description of the coefficient switching operation in the color adjustment unit 440 will be described later in the second embodiment.

As described above, a user such as an operator manually performs coefficient setting (coefficient switching) of the matrix calculation unit 436 that generates a spectral image signal according to the type and characteristics of the living body to be observed on the living body surface in this embodiment. FIG. 27 shows a flowchart of the operation when observing.
When the power is turned on, the control unit 42 and the like are in an operation state, and each unit is controlled so as to be in an operation state in the normal observation mode as shown in step S1 as an initial setting.
Then, as shown in step S2, an observation mode switching instruction is awaited. When the operator gives an instruction to switch the observation mode from the operation panel 441 or the like, the control unit 42 performs control to switch to the operation state of the spectral image observation mode as shown in step S3.

Further, when the control for switching to the operation state of the spectral image observation mode is performed, as shown in step S4, for example, the control unit 42 stores information on the coefficient set as the spectral image observation mode at the time of switching on the display monitor 106. Control to display. As the contents of the coefficient information display at the time of switching in step S4, for example, the coefficient information set by the matrix calculation unit 436 in the spectral image observation mode set at the time of switching is displayed.
Thereafter, in the next step S5, the control unit 42 confirms whether to perform coefficient switching (selection) for the user.
Then, the user (operator) determines whether or not to perform switching according to the characteristics and type of the subject actually observed, more specifically, the characteristics and type of the biological mucous membrane. When switching is performed, as shown in step S6, after performing an operation of manually switching the coefficient according to the type of subject, more specifically, the tissue type of the biological mucous membrane, and the like, Proceed to S7.

In this way, the biological mucosa actually observed may be switched depending on the type of the site to be observed, such as the esophageal mucosa, gastric mucosa, large intestine mucosa, etc. You may make it switch according to the characteristic of spectral reflectance, a kind, etc. of the part made into observation objects, such as the name and kind of the epithelium to comprise.
For example, the epithelial tissue of the esophageal mucosa is a stratified squamous epithelium, and the stomach and large intestine mucosa are covered with a single-layered columnar epithelium, and therefore the basic spectral characteristics thereof are different. For this reason, if a matrix for spectral image estimation calculated using basic spectral characteristics estimated from a set of spectral reflectance data of the esophageal mucosa is used in a colon examination, it is difficult to obtain a desired result.
In order to obtain an accurate spectral image, it is necessary to perform this matrix calculation using basic spectral characteristics according to the type and tissue type of the biological mucosa, and it is desirable to use an appropriate matrix calculation in actual observations. .

  Therefore, in this embodiment, a selection switch 441b (see FIG. 4) that performs coefficient switching or coefficient selection of the matrix calculation unit 436 provided on the operation panel 441 or the like is provided as a coefficient setting switching means constituting the interface means. Operate.

  By the operation, the coefficient 443a corresponding to the spectral characteristic of the observation target is read from the LUT 443, and switching is performed so that an appropriate matrix calculation is performed with the coefficient 443a.

In step S7, the control unit 42 waits for an observation mode switching instruction. When the surgeon performs a switching instruction operation, the control unit 42 returns to step S1 and switches to the normal image observation mode. Then, the above-described processing is repeated. In step S5, when the coefficient is switched, items such as a switching (selection) item according to the type of the subject and a switching (selection) according to the biological feature are displayed, and the user further selects the biological mucous membrane from the item. It is also possible to make it easier to switch and set the coefficient corresponding to the spectral characteristics that make it easier to properly observe the type and blood vessels.
Thus, according to the present embodiment, a pseudo narrow band filter is generated by electrical signal processing using a color image signal of a normal electronic endoscopic image (normal image). As a result, in this embodiment, a spectral image having a desired deep tissue information such as a blood vessel running pattern, etc. without using an optical narrow-band bandpass filter for spectral images can be set by coefficient setting switching and coefficient switching. The color conversion coefficient of the color adjustment unit 440 can be appropriately set according to the spectral image.

In addition, the present embodiment makes it possible to realize an expression method that makes use of the feature of depth information when observing a narrow-band spectral image. More specifically, tissue information at a desired depth near the surface of a living tissue, more specifically The blood vessel running pattern or the like can be effectively separated and visually recognized.
In particular, in the case of a three-band spectral image in the color adjustment unit 440, for example, an image corresponding to 415 nm corresponds to the color channel Bch of the display monitor 106, for example, an image corresponding to 445 nm corresponds to the color channel Gch, and corresponds to 500 nm, for example. When the images to be assigned are assigned to the color channels Rch, according to the present embodiment, the following image effects can be obtained.

(A) The epithelium or mucous membrane of the outermost layer of living tissue is reproduced with a low saturation color, and the capillaries of the outermost layer are reproduced with low luminance, that is, dark lines, so that the outermost capillaries are highly visible Is obtained.
(B) At the same time, since a blood vessel at a deeper position than the capillary is rotated and reproduced in the blue direction in the hue direction, it is easier to distinguish from the capillary on the outermost layer.
According to the channel assignment method, residues and bile observed in a yellow tone under normal observation in a colonoscopy are reproduced in a red tone.
In the color adjustment unit 440 in Example 2 described later, substantially the same effect can be obtained even in the case of a two-band spectral image.

FIG. 28 shows an electronic endoscope apparatus 100 according to a first modification of the present embodiment.
In the electronic endoscope apparatus 100 according to the first embodiment, the coefficient switching setting by the matrix calculation unit 436 can be operated from the operation panel 441 or the like, but in this modification, as an interface unit connected to the control unit 42. The centralized controller 461 can be operated.
Further, in this modification, a microphone 462 that accepts a coefficient switching instruction by a user's voice as an electrical signal is connected to the main body 105, and a voice recognition circuit 463 is provided in the main body 105. The voice signal input from the microphone 462 from the user is recognized by the voice recognition circuit 463, and the voice recognition result is input to the control unit 42.
The control unit 42 appropriately performs matrix calculation by the matrix calculation unit 436 according to the coefficient 443a stored in the LUT 443 in response to an instruction signal such as coefficient switching by voice from the centralized controller 461 and microphone 462 by the user. In the present modification (and the next modification), the control unit 42 is shown as having the function of the coefficient control unit 442 in FIG. Of course, the coefficient may be switched from the control unit 42 via the coefficient control unit 442.

Further, the centralized controller 461 or the like may be used for an interface for performing an observation mode switching operation or an observation mode selection operation that is started up when the power is turned on. In addition, an interface such as a foot switch (not shown) may be provided.
Further, the electronic endoscope apparatus 100 as a specific example of the living body observation apparatus may have a configuration as in the second modification shown in FIG. In the electronic endoscope apparatus 100 of the second modification shown in FIG. 29, an ID memory 161 is provided in, for example, the connector 11 in the endoscope 101, and an ID memory 162 is provided in the light source unit 41 in the main body 105, for example. Yes.

  The ID information stored in each of the ID memory 161 and the ID memory 162 is input to the control unit 42 when the power is turned on, for example. The control unit 42 sets the coefficient switching setting by the matrix calculation unit 436 according to the components such as the endoscope 101 in the electronic endoscope device 100 that is actually combined to be a component on the electronic endoscope device 100 side. It is controlled so as to automatically become an appropriate setting according to.

The operation in this case is as shown in the flowchart of FIG. The operation shown in FIG. 30 is basically the same as the operation shown in FIG. 27 except that the process shown in step S8 is performed between steps S3 and S4.
In step S3, the control unit 42 reads information in the ID memory 161 of the endoscope 101 and the ID memory 162 of the light source unit 41 in the next step S8 after switching to the spectral image observation mode. Then, the control unit 42 corresponds to the color imaging characteristics of the CCD 21 employed in the endoscope 101 from each information, the type of the lamp 15 of the light source unit 41, the emission wavelength characteristics (spectral characteristics), and the like. The coefficient appropriate for the calculation at 436 is read from the LUT 443. Then, the control unit 42 sends the coefficient to the matrix calculation unit 436 and performs automatic coefficient switching setting.

29 includes a plurality of LUTs 443 corresponding to the color imaging characteristics of the CCD 21, the type of the lamp 15 of the light source unit 41, the emission wavelength characteristics (spectral characteristics), and the like (in addition to the coefficient 443a shown in FIG. 4). The coefficient 443b is stored.
Thereafter, the process proceeds to step S4 ′ corresponding to the next step S4 in FIG. In step S4 ′, the control unit 42 performs control so as to display information on the coefficient set according to the observation object set at the time of switching (default or previous selection). The processing after this step S4 'is the same as in the case of FIG.

  According to this modification, when the spectral characteristics of the color filter of the CCD 21 mounted on the endoscope 101 that is actually connected and used vary depending on the type of the endoscope 101 and the individual differences, Even if the spectral characteristics differ depending on the type of lamp 15 as the light source in the unit 41 (for example, types of halogen lamps and xenon lamps having different spectral characteristics of light emission) and individual differences, the influence of these differences is reduced. A more reliable spectral image can be obtained.

  If the ID memory 161 or the like is not provided, it may be manually switched to an appropriate coefficient. In addition, a mode in which the coefficient switching setting is automatically performed and a mode in which the coefficient is manually set may be prepared so that the user can perform the selection regardless of the presence of the ID memory 161 or the like.

  In the present modification, the mode for automatically performing the coefficient when performing the matrix calculation by the matrix calculation unit 436 has been described. However, the coefficient when performing the color adjustment or color conversion in the color adjustment unit 440 is automatically set in the same manner. You can also In this way, when the combination of the endoscope 101 and the like constituting the electronic endoscope apparatus 100 is the same, the same color tone state can be automatically set. Further, in the matrix calculation unit 436 and the color adjustment unit 440, each coefficient may be automatically set based on the ID information of the ID memories 161 and 162.

  When the endoscope apparatus main body 105 includes the light source unit 41, the control unit 42 may perform automatic setting of the coefficient only with the ID information on the endoscope 101 side. Of course, even when the endoscope apparatus main body 105 includes the light source unit 41, automatic setting of coefficients when performing matrix calculation in the matrix calculation unit 436 in consideration of the spectral characteristics of the lamp 15 in the light source unit 41. May be performed.

  In the processing of FIG. 27 or FIG. 30, when the observation mode is set or switched as shown in FIG. 31, the observation mode may be explicitly displayed.

  In the example of FIG. 31, in the first step S1 ′, the control unit 42 sets the normal image observation mode as in step S1. Furthermore, the control unit 42 performs control to explicitly display the observation mode.

For example, as shown in FIG. 32A, the control unit 42 clearly indicates that the normal image observation mode or the normal image is displayed, for example, below the display area of the normal image displayed on the display monitor 106. Control to display the designated NI. The control unit 42 may perform control so that Normal Imaging, a normal image, and the like are displayed instead of displaying the character information by the NI.
Similarly, in step S3 ′ corresponding to step S3, when switching to the spectral image observation mode is similarly performed, the control unit 42 explicitly displays the observation mode.
For example, as shown in FIG. 32B, the control unit 42 performs control so that NBI that explicitly indicates the spectral image is displayed, for example, below the display area of the spectral image. The control unit 42 may perform control so as to display Narrow Band Imaging, a spectral image, or the like instead of displaying NBI.

By doing in this way, the user can confirm the observation mode actually set more reliably.
Further, as shown in FIG. 32C, in the case of a normal image, the display of NI or the like may not be performed, and control may be performed such that NBI is displayed only in the case of a spectral image. .
32A to 32C show an example in which the observation mode is explicitly shown on the display monitor 5, but the observation mode is explicitly displayed on the operation panel 441, thereby allowing the user to May be formed with an interface means for confirming the state of the observation mode.
For example, as shown in FIG. 32D, an LED 91 for explicitly displaying an observation mode (in this case, a spectral image observation mode) is provided on the operation panel 441. The control unit 42 performs control so that the LED 91 is turned off in the normal image observation mode and turned on in the spectral image observation mode.

  Note that it is better to display NBI characters or the like in the vicinity of the LED 91 to indicate whether or not the LED 91 is lit in the spectral image observation mode.

In the example shown in FIG. 32E, the operation panel 441 is provided with an LED 92 that turns on the NBI character itself or lights up the surroundings other than the character. Then, the control unit 92 may perform control such that the LED 92 is turned off in the normal image observation mode and turned on in the spectral image observation mode as described above.
Furthermore, in the example shown in FIG. 32F, an LED 93 is provided on the operation panel 441 so that the NBI character itself is lit or the surroundings other than the characters are lit. Then, the control unit 42 turns on (displays) the LEDs 93 in different colors according to the observation mode, for example, lights in green so as to indicate a light-off state in the normal image observation mode, and turns on white in the spectral image observation mode. You may control. Here, an example in which observation mode information or observation image information is displayed on the operation panel 441 as an interface means has been described, but information such as an observation mode may be displayed on a keyboard or other interface means. .

  In the case of the configuration as shown in FIG. 29, using the information written in the ID memory 161 or the like of the endoscope 101 as shown in FIG. 33, the coefficient setting suitable for each observation mode is switched to the observation mode. You may make it carry out in conjunction.

When the power is turned on, the control unit 42 reads information in the ID memory 161 of the endoscope 101 and the ID memory 162 of the light source unit 41 in the first step S11.
In the next step S12, the control unit 42 determines whether or not the observation mode is set when the power is turned on. Information on the setting of the observation mode is stored, for example, in a nonvolatile memory (not shown) in the control unit 42. When the user sets the observation mode to be started up when the power is turned on from the keyboard 451, the control unit 42 stores the setting information in the nonvolatile memory.
Then, the control unit 42 reads the setting information and starts up in a preset observation mode. If no setting has been made, for example, the normal image observation mode is started.

  For this reason, if the control unit 42 determines in step S12 that the observation mode at power-on is set, whether or not the observation mode set in the next step S13 is the normal image observation mode. Make a decision.

When the normal image observation mode is set and when the observation mode at the time of power-on is not set in step S12, the process proceeds to step S14a, and the control unit 42 moves the electronic endoscope apparatus 100 to the normal image observation mode. Set to normal image observation mode and start up.
When the normal image observation mode is set, the control unit 42 sets parameters (coefficients) corresponding to the observation mode. That is, as shown in step S15a, the setting is performed in conjunction with the parameter corresponding to this observation mode.
For example, the control unit 42 performs light amount control of the light source unit 41 according to the observation mode. In this case, the target value (reference value) to be controlled for light amount is set to a target value suitable for the observation mode. Alternatively, the parameter for variably setting the target value is changed.

  In addition, when performing light quantity control, when the light quantity control can be performed with either the average value or the peak value of the brightness, the user may be able to select the type of light quantity control. In addition, the control unit 42 sets the set values of various parameters such as the type of contour enhancement, the type of gradation conversion, the type of color painting, etc. Such information is stored individually, and the control unit 42 automatically switches the setting conditions of parameters other than those necessary for the observation mode when the mode is switched.

When the control unit 42 performs such control, a normal image can be displayed with appropriate brightness, a color tone suitable for diagnosis, an appropriate contour state, and the like.
After setting this parameter, in step S16a, the control unit 42 waits for an observation mode switching instruction. Then, when an instruction to switch the observation mode is given, the process proceeds to step S14b.
In step S13, when the setting of the observation mode when the power is turned on is not the normal image observation mode, the process proceeds to step S14b, and the control unit 42 sets the spectral image observation mode. Further, as shown in the next step S15b, the control unit 42 performs setting in conjunction with parameters corresponding to the observation mode.

  In this case, the control unit 42 controls the light amount control so that the target value is suitable for the spectral image observation mode, and the matrix calculation coefficient by the matrix calculation unit 436 is set to the color of the CCD 21 as in step S8 of FIG. Switching is set according to the spectral characteristics of the filter or the like.

In this case, the target value in the spectral image observation mode is set to a value lower than the target value in the normal image observation mode.
The control unit 42 performs light amount control using parameters such as the target value so that R, G, and B signals that are not saturated are input to the matrix calculation unit 436 so that the spectral image signal can be appropriately calculated. Corresponding to spectral characteristics such as color filters, coefficient switching is performed so that the matrix calculation unit 436 can appropriately calculate the spectral image signal. That is, the control unit 42 can perform appropriate signal processing. Further, the control unit 42 may set other parameters such as the contour enhancement to values suitable for spectral image observation.
After setting this parameter, in step S16b, the control unit 42 waits for an observation mode switching instruction. Then, when the observation mode switching instruction is given, the process proceeds to step S14a.

According to the present modification, the observation mode that starts up when the power is turned on can be started up in the observation mode according to the user's setting. In addition, in conjunction with the switching of the observation mode, various parameters can be set smoothly without requiring a user to perform setting operations so that image display and signal processing are performed in a state suitable for the switched observation mode. Therefore, according to this modification, operability is improved.
In the description of the operation in FIG. 33, the example in which the observation mode that is started up when the power is turned on is set using the information set by the user before the power is turned on. Sometimes, a specific key input is performed to set an observation mode that starts up when the power is turned on.
A part of the operation in this case is shown in the flowchart of FIG. For example, when the power is turned on, the control unit 42 performs the same processing as step S11 in FIG. Thereafter, as shown in step S18, the control unit 42 determines whether or not there is a predetermined key input operation set in advance so as to select an observation mode to be started up when the power is turned on.

When the user wants to select an observation mode to be started up when the power is turned on, the user operates a predetermined key on the keyboard 451 or the like to input a key.
If it is determined that a predetermined key input has been made, the control unit 42 controls to display a selection screen for selecting an observation mode to be started up when the power is turned on, as shown in step S19.
For example, the control unit 42 displays a screen for selecting whether to start in the normal image observation mode or the spectral image mode, and asks the user to make a selection.
Thereafter, in substantially the same manner as Step S13 in FIG. 33, the control unit 42 determines whether or not the selected observation mode is the normal image mode. On the other hand, if it is determined in step S18 that the predetermined key operation has not been performed, the process proceeds to step S14a in FIG. The subsequent processing is the same as in FIG.

According to this modification, the user can perform observation mode selection setting at startup. Although the observation mode can be selected by operating the keys, as an alternative, the observation mode to be activated when the power is turned on may be determined by a previously operated key.
In the above-described first embodiment (including the modified example), the configuration in which the matrix calculation in the matrix calculation unit 436 for spectral image estimation is appropriately switched has been described. You may make it switch appropriately.

Next, Embodiment 2 of the present invention will be described with reference to FIG. FIG. 35 illustrates a configuration of a peripheral portion of the color adjustment unit in the electronic endoscope apparatus of the second embodiment. This embodiment is a specific example in which the color adjustment of the color adjustment unit 440 is appropriately performed using, for example, two spectral image signals ΣF2 and ΣF3 in the configuration of FIG. 4 of the first embodiment. Therefore, in this embodiment, the integrating unit 438a in FIG. 4 is not provided, and a spectral channel image signal to be displayed in color on the display monitor 5 is generated from the two spectral image signals ΣF2 and ΣF3.
In the present embodiment, as a specific example of a method for appropriately switching the calculation coefficient of the color adjusting unit, color display of a spectral image is performed as follows using two spectral image signals ΣF2 and ΣF3 output from the integrating units 438b and 438c. Is done appropriately.

For example, the spectral image is displayed as a pseudo color image on the display monitor 5 using the spectral images (spectral channel images) having the center wavelengths of about 415 nm and about 540 nm as the subject with the digestive tract mucosa as the subject.
As a method of assigning the spectral image to the color channel (of the display monitor 106), considering the visibility on the display monitor 5, a spectral channel image of 540 nm is displayed on the R channel of the display monitor 106, and 415 nm is applied on the G and B channels. It is considered preferable to display the spectral channel image after adjusting the output of the spectral channel image.
In this case, by fixing the output (signal gain) of the R channel and adjusting the output (signal gain) of the G and B channels, the biological mucosa of the subject having different spectral reflectance characteristics such as esophageal mucosa and large intestine mucosa The color of the spectral color image can be adjusted according to the type of epithelial tissue or the like. The configuration of the color adjustment unit 440 in this case is shown in FIG. 35 as an example in which three gain variable amplifiers Ar, Ag, Ab are employed.

For example, if the output signal to the R, G, B channel of the display monitor 5 is R, G, B, 415 nm spectral image is b, 540 nm spectral image is g,
R = k1 * g, G = k2 * b, and B = k3 * b are set. Here, k1, k2, and k3 are weighting factors.
For example, when observing the large intestine mucosa, k1>k2> k3 is set, and when observing the esophageal mucosa, k1> k2 ′> k3 ′ and k2> k2 ′ are set.
In the example of FIG. 35, gain control data corresponding to a coefficient that defines the gains of the variable gain amplifiers Ar, Ag, Ab is stored in the LUT 191 in advance according to the type of biological mucosa to be observed. The gain control data output from the LUT 191 is applied to the gain control terminal, whereby the gains of the variable gain amplifiers Ar, Ag, Ab to which the gain control data is applied are controlled.

In FIG. 35, for example, colon gain control data 191a, esophageal gain control data 191b, and the like are stored in the LUT 191, and the user operates the selection switch 441a on the operation panel 441 to perform the colon gain control data 191a and the like. A selection signal (control signal) for selecting the esophageal gain control data 191b can be applied to the LUT 191. In response to the selection signal, the LUT 191 can apply the corresponding gain control data to the gain variable amplifiers Ar, Ag, Ab.
According to this embodiment having such a configuration, when the esophageal mucosa is to be observed, the esophageal gain control data 191b is selected so that the stratified squamous epithelium is reproduced in white and the capillaries in the epithelium are highly visible. .
When the user wants to observe the large intestine mucosa, the user can display the polyp and the fine pattern on the surface of the mucous membrane with good visibility by selecting the gain control data 191a for the large intestine. Therefore, according to the present embodiment, it is possible to display a biological feature such as a fine structure on the surface of the mucous membrane to be observed with good visibility.

On the other hand, when it is desired to reproduce a blood vessel deep in the mucous membrane with higher contrast, a variation such as adding a g spectral image reflecting the blood vessel to the b spectral image at a certain ratio and reproducing it with the G channel is also possible. A part of the configuration example in this case is shown in FIG.
FIG. 36 shows a configuration in which the g spectral image is further input to the gain variable amplifier Ag via the multiplier 192 in the configuration of FIG. The multiplier 192 receives a multiplication coefficient from the LUT 191.
In this case, for example, in the case of the above-described large-intestine gain control data 191a in the LUT 191, this multiplication coefficient is 0 (in this case, the same action as in FIG. 35), and the blood vessel on the deeper side is further increased. When colon gain control data (abbreviated as colon (2) in the figure) 191a ′ for reproduction with high contrast is selected, the multiplication coefficient is set to m (0 <m <1), for example. Has been.

When the user selects the large intestine gain control data 191a through the selection signal, the large intestine capillaries and fine patterns can be easily observed, that is, in the fine pattern emphasis mode, and the large intestine gain control data 191a ′ Is selected, the blood vessel on the deep mucosa side can be observed in a state where it is easy to visually recognize with high contrast, that is, the deep blood vessel enhancement mode.
As described above, by preparing a plurality of modes of the color adjustment means for switching the color adjustment and switching the modes using a predetermined user interface, it is possible to display a spectral image easily (that is, an appropriate pseudo) color display. It becomes possible.
In this embodiment, the specific example in which the color adjustment of the color adjustment unit 440 is appropriately performed using the two spectral image signals ΣF2 and ΣF3 has been described. However, the three spectral image signals ΣF1, ΣF2, and ΣF3 are used. The color adjustment unit 440 may perform color adjustment.

Next, Embodiment 3 of the present invention will be described with reference to FIGS.
In the present embodiment, in a spectral image observation mode for observing a spectral image, when a preset condition is met, control for forcibly switching to the normal image observation mode is performed. More specifically, when the brightness of the spectral image reaches a threshold value set in advance to determine a dark image, the control unit 42 switches the switching unit 439 to switch to the normal image observation mode. Take control.
The electronic endoscope apparatus 100 according to the third embodiment illustrated in FIG. 37 is different from the endoscope apparatus 100 illustrated in FIG. 4 in that, for example, the spectral image signals F1, F2, and F3 output from the matrix calculation unit 436 And a signal of a comparison result (determination result) compared with a preset brightness level threshold value Vth is output to the control unit 42.

For example, the brightness determination unit 171 determines whether or not the signal of the sum of the absolute values of three spectral image signals for one frame is equal to or less than a threshold value Vth set for determining a dark image state, for example. (Comparison judgment) is performed. Then, the brightness determination unit 171 outputs a signal of the comparison result to the control unit 42. When this condition is met, the control unit 42 controls switching of the switching unit 439, and performs control to forcibly switch the observation mode to the normal image observation mode.
In the first embodiment, the matrix calculation unit 436 is configured by hardware using the resistor group 31-1a as shown in FIG. 8, but in this embodiment, for example, as shown in FIG. It is performed by numerical data processing (processing by software using a program).
The matrix calculation unit 436 shown in FIG. 38 has an image memory 50 for storing RGB color image signals. The coefficient register 151 stores each value of the matrix “A ′” shown in the equation (21) as numerical data.
The coefficient register 151 and the image memory 50 are connected to the multipliers 53a to 53i, and the multipliers 53a, 53d, and 53g are connected to the multiplier 54a, and the output of the multiplier 54a is input to the integrating unit 438a in FIG. Is done.

The multipliers 53b, 53e, and 53h are connected to the multiplier 54b, and the output thereof is input to the integrating unit 438b. The multipliers 53c, 53f, and 53i are connected to the multiplier 54c, and the output thereof is input to the integrating unit 438c.
As an operation of this embodiment, the input RGB image data is once stored in the image memory 50. Next, each coefficient of the matrix “A ′” from the coefficient register 151 is multiplied with the RGB image data stored in the image memory 50 by a multiplier by an arithmetic program stored in a predetermined storage device (not shown). The
FIG. 38 shows an example in which the R signal and each matrix coefficient are multiplied by multipliers 53a to 53c. Also, as shown in the figure, the G signal and each matrix coefficient are multiplied by multipliers 53d to 53f, and the B signal and each matrix coefficient are multiplied by multipliers 53g to 53i.

  The data multiplied by the matrix coefficients are respectively output from the multipliers 53a, 53d and 53g by the multiplier 54a, by the multipliers 53b, 53e and 53h by the multiplier 54b and by the multipliers 53c, 53f, The outputs of 53i are respectively multiplied by the multiplier 54c.

  The output of the multiplier 54a is sent to the integrating unit 438a. The outputs of the multiplier 54b and the multiplier 54c are sent to the integrating units 438b and 438c, respectively.

Further, the coefficient register 151 is connected to the coefficient control unit 442 in FIG. 4, and when an observation region is selected, the matrix coefficient corresponding to the observation region is read from the LUT 443 from the coefficient control unit 442 and the coefficient register 151. Stored in. Then, matrix calculation processing suitable for the observation region is performed by the coefficient register 151 using the matrix coefficient, and spectral image signals F1, F2, and F3 are generated.
Also in the case of the matrix calculation unit 436, a spectral image capable of displaying a blood vessel pattern clearly can be obtained as in the first embodiment.
Further, in the present embodiment, the matrix processing is not performed by hardware as in the first embodiment, but is performed using software. For example, each matrix coefficient is changed without requiring hardware change. be able to.

  In addition, matrix coefficients are stored not only as a result value, that is, as a matrix “A ′”, but also as S (λ), H (λ), R (λ), G (λ), and B (λ). When the matrix “A ′” is obtained and used by performing calculations as necessary, only one of the elements can be changed, and convenience is improved. For example, it is possible to change only the spectral characteristic S (λ) of the illumination light. Other configurations are the same as those of the first embodiment or its modification.

Next, the operation of switching the observation mode based on the determination result by the brightness determination unit 171 according to the present embodiment will be described with reference to FIG.
When the power is turned on, the control unit 42 and the like are in an operating state, and control is performed so that the normal image observation mode is in an operating state as shown in step S21 as an initial setting.
Then, as shown in step S22, a state of waiting for an instruction to switch the observation mode is entered. When a user such as an operator issues an observation mode switching instruction from the operation panel 441 or the like, the control unit 42 performs control to switch to the operation state of the spectral image observation mode as shown in step S23.

Then, spectral image signals F1, F2, and F3 subjected to matrix calculation by the matrix calculation unit 436 are generated. These spectral image signals F1, F2, and F3 are integrated by the integrating units 438a to 438c, and are converted into spectral channel image signals Rnbi, Gnbi, and Bnbi that have been adjusted in color through the color adjusting unit 440, and pass through the switching unit 439 to the display monitor 106. Applied to the R channel, G channel, and B channel, and the spectral image is displayed in color on the display surface of the display monitor 106.
In this spectral image observation mode, the output signal of the matrix calculation unit 436 is input to the brightness determination unit 171 that determines the brightness. As shown in step S24, the brightness determination unit 171 sets the spectral image. An operation is performed to determine whether or not the threshold value Vth has been reached.

If this condition is not satisfied, in the next step S25, the control unit 42 determines whether there is an instruction to switch the observation mode. If there is no instruction to switch the observation mode, the process returns to step S24, and brightness determination processing is performed.
On the other hand, when there is an instruction to switch the observation mode in step S25, as shown in step S6, the control unit 42 performs control to switch to the operation state of the normal observation mode.
In the present embodiment, when it is determined in the determination process in step S24 that the brightness detected by the brightness determination unit 171 has reached the threshold value Vth or less, the process proceeds to step S26. In step S26, the control unit 42 performs control to switch to the operation state of the normal observation mode even when the observation mode switching instruction is not performed.

After performing control to switch to the normal observation mode, the process returns to step S22 and the above-described process is continued.
As described above, in the spectral image observation mode, when the brightness of one frame of each image is equal to or lower than the threshold value Vth, it is difficult to identify the blood vessel structure or the like from the spectral image. Therefore, by switching to the normal observation image, it is possible to make the image easy to observe, and the operation for switching by the operator can be made unnecessary. Therefore, according to the present embodiment, the operability is improved.

As a modification of the present embodiment, when the brightness of the brightness determination unit 171 is larger than the threshold value Vth and is not so dark as to switch to the normal image observation mode, the brightness of the screen (scene) in that case is set. Accordingly, for example, a coefficient setting switching unit configured to switch the color tone coefficient of the color adjusting unit 440 may be formed.
Part of the operation in this case is shown in FIG. Here, as a simple example, the case of two brightness levels equal to or higher than the threshold Vth will be described, but the present invention can be similarly applied to the case of three or more brightness levels. The threshold value for dividing the two brightnesses is Vth2.
In step S24 of FIG. 39, when the brightness is equal to or higher than the threshold value Vth, as shown in step S27, the brightness determination unit 171 further determines whether the brightness is equal to or lower than the second threshold value Vth2. Do.

If it is larger than the threshold value Vth2, the process proceeds to step S25 as in the case of FIG. 39 (here, for the sake of simplicity, it is assumed that a color tone suitable for a case larger than the threshold value Vth2 is set).
On the other hand, when the current brightness is smaller than the threshold value Vth2, the control unit 42 displays whether or not to perform coefficient switching suitable for brightness as shown in step S28, and whether or not to perform switching to the user. Wait for the determination. If switching is selected, as shown in step S29, the control unit 42 performs coefficient switching to obtain a color coefficient suitable for the brightness, and then proceeds to step S25. Also, when the switch is not selected, the process proceeds to step S25. Other processes are the same as those in FIG.

According to this modification, it is possible to display with an appropriate color tone according to the brightness of the scene. For example, when the image becomes dark, the coefficient is switched so as to increase the saturation, for example, as compared with the case of the color tone when it is bright. By doing in this way, even when the brightness is lowered, it is possible to maintain a function that makes it easy to visually recognize the feature amount of the living body from the color tone in the bright case.
It is to be noted that the color tone mode for switching the color tone coefficient in accordance with the value of the scene brightness in advance is selected, and when the color tone mode is selected by the user, the scene brightness value is automatically selected. The color tone coefficient may be switched according to the display and displayed.

  In the present embodiment, the brightness is determined from the spectral image. However, the brightness of the spectral image is estimated from the brightness of the normal image, and the normal observation mode is switched when the brightness falls below a certain threshold. It can also be done.

  In this embodiment, when the brightness of the spectral image is equal to or less than a predetermined value corresponding to a dark image state, the normal observation mode is switched. However, the following embodiment 4 may be used.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 41 shows the configuration of an electronic endoscope apparatus 100 according to Embodiment 4 of the present invention. The electronic endoscope apparatus 100 according to the present embodiment includes a color tone determination unit 172 that determines a color tone instead of the brightness determination unit 171 in the configuration of FIG.
Further, in this embodiment, a frame sequential light source 41B is provided instead of the simultaneous light source 41 used in the first embodiment.
In the light source unit 41 </ b> B, a diaphragm 25 is provided in front of the lamp 15, and an RGB filter 23 is provided in front of the diaphragm 25. The diaphragm 25 is connected to the diaphragm control unit 24. The light source unit 41 </ b> B restricts the light beam to be transmitted among the light beams emitted from the lamp 15 according to the control signal from the diaphragm control unit 24, and changes the light amount. The RGB rotation filter 23 is connected to the RGB rotation filter control unit 26 and is rotated at a predetermined rotation speed.

The operation of the light source unit 41B in the present embodiment is as follows. R, G, B illumination light, that is, R, G, B plane sequential illumination light, is emitted from the light source 41B. The R, G, B plane sequential illumination light is irradiated into the subject through the light guide 14 and the reflected light is received by the CCD 21.
The CCD 21 in this case is a monochrome CCD 21 not provided with a color filter, and a signal (imaging signal) obtained by the CCD 21 is provided in the endoscope apparatus body 105 according to the irradiation time. The signals are distributed by a switching unit (not shown) and input to the S / H circuits 433a to 433c, respectively.

That is, when the R illumination light is irradiated from the light source unit 41 via the R filter, the signal obtained by the CCD 21 is input to the S / H circuit 433a. When the CCD 21 provided with a color filter is employed, a simultaneous light source unit 41 can be employed as shown in FIG.
Further, the hue determination unit 172 sets a (first) hue / saturation setting unit 173 that sets a hue range corresponding to the hue to be detected as shown in FIG. 42, and this hue / saturation setting unit 173. A hue / saturation determination unit 174 that determines whether or not the condition of the color tone range set by the above is satisfied.
In this case, the hue range by the hue / saturation setting unit 173 is input from the keyboard 451 or the like via the control unit 42, and can be set by the user or the like. The hue / saturation determination unit 174 receives the spectral image signals F1, F2, and F3 from the matrix calculation unit 436. Then, the hue / saturation determination unit 174 determines whether or not these signals are included in the hue range set by the hue / saturation setting unit 173, and outputs the determination result to the control unit 42. .

  The control unit 42 performs control such as switching of the switching unit 439 according to the determination result.

For example, a predetermined area for one frame that the color tone of the current spectral image signal input to the color tone determination unit 172 falls within the color tone range determined by the hue / saturation determination unit 174 in the color tone determination unit 172. When detected above, the hue / saturation determination unit 174 outputs a determination signal to the control unit 42 that it is within the tone range.
Then, the control unit 42 forcibly switches to the normal image observation mode and switches the switching unit 439 so that a color image signal corresponding to the normal image is output to the display monitor 5.
In the present embodiment, the hue determination unit 172 is provided with a second hue / saturation setting unit 175. In the second hue / saturation setting unit 175, the color tone to be detected from the keyboard 451 or the like via the control unit 42 is registered.

Further, it is also possible to register and set a color tone range corresponding to a color tone to be detected from the spectral image signal data actually captured.
In other words, when there is typical spectral image signal data to be detected, the image data is fetched into the second hue / saturation setting unit 175 via the control unit 42 in accordance with a fetching instruction from the keyboard 451 or the like. . In this case, the data can be processed as necessary to set a color tone range for detecting a color tone close thereto. Then, the user can make a hue determination in a hue range to be prioritized in the (first) hue / saturation setting unit 173 or the second hue / saturation setting unit 175.
In this way, various hues can be registered in the second hue / saturation setting unit 175.

The operation in the case of this modification will be described next. In the present modification, instead of determining whether or not the detected brightness in step S24 in FIG. 39 is equal to or less than the threshold value Vth, the color tone detected by the color tone determination unit 172 is within a predetermined color tone range. It is determined whether or not a certain area or more is detected in one screen.
When it is detected that a predetermined color tone range has been reached by a certain value or more, the control unit 42 performs control to forcibly switch from the spectral image observation mode to the normal observation mode. Other operations are the same as those described with reference to FIG.
According to the present embodiment, when a predetermined color tone is desired such that the normal image observation mode is more desirable than the spectral image observation mode, the normal image observation mode can be forcibly set. For example, in the case of a colonoscopy, if a so-called residue such as a meal or stool remains, the spectral signal color image is displayed in red like a bleeding color. This is because the residue strongly absorbs blue light and strongly reflects green light. Usually, stool or the like is washed as a pretreatment before colonoscopy.

However, depending on the state of the large intestine, it may not be washed completely, or a considerable amount of residue may remain.
In such a case, if the spectral color image is left as it is, it may be difficult to secure a field of view suitable for the inspection. It is desirable to return to the image observation mode.
In this embodiment, in such a case, the signal processing control means is provided with the color tone detection means as described above, more specifically, for example, a means for detecting hue and saturation. When it is determined that the residue occupies a certain area or more on the screen, control is performed to return (or switch) the observation mode switching means to the normal observation mode.

As a modification of the present embodiment, a plurality of hues or desired ones are set in the second hue / saturation setting unit 175, and one of them is detected in the spectral image observation mode. In this case, the control unit 42 may perform control to return to the normal observation mode. In addition to the above-mentioned residues, there is a large amount of bile, such as when the mucous membrane of living tissue cannot be properly observed as a spectral image, or when the color tone of the pigment greatly affects the spectral image due to color difference dispersion If it is not suitable for the spectral image observation mode, it is desirable to forcibly return to the normal image observation mode.
Part of the operation in this case is shown in FIG. FIG. 43 shows a process in which the determination process part in step S24 of FIG. 39 is changed.

Before starting this operation, the user performs, for example, a residue, bile, or a typical pigment application as a hue to be detected in the second hue / saturation setting unit 175 by an instruction operation from the keyboard 451 or the like. Color tone data of colored pigment is registered in advance.
The user is assumed to have selected a setting mode for returning to the normal observation mode when, for example, any one of these residues, bile, and color tone is detected by a predetermined amount or more. After switching to the spectral image observation mode as in step S23 of FIG. 39, the color tone determination unit 172 enters a state of monitoring whether a predetermined color tone has been achieved. That is, as shown in step S24a, it is determined whether or not the color tone of the current spectral image is the color tone of the residue, and if it is determined that the color tone of the residue is equal to or larger than a certain area, the control unit 42 normally Forcibly switch to image observation mode.
If the color tone of the current spectral image is not the color tone of the residue, the process proceeds to step S24b, where it is determined whether the color tone of the bile is equal to or greater than a certain area. As described above, the control unit 42 forcibly switches to the normal image observation mode.

  If the color tone of the current spectral image is not the color tone of bile, the process proceeds to step S24c, where it is determined whether the color tone is colored with a pigment, and it is determined that the color tone colored with the pigment has a certain area or more. Then, as shown in step S26, the control unit 42 forcibly switches to the normal image observation mode.

On the other hand, if the color tone of the current spectral image is not a color tone colored with a pigment, the process proceeds to step S25, and the control unit 42 waits for an observation mode switching instruction.
According to this modification, when the color tone is unsuitable for performing observation in the spectral image observation mode, the mode can be forcibly switched to the normal image observation mode, and the user can save the trouble of switching. Therefore, according to this modification, operability is improved.
In the above-described embodiment, the illumination light amount (light amount from the light source unit) is controlled and adjusted in order to avoid saturation of the RGB color signals. On the other hand, there is a method of adjusting (using) the electronic shutter of the CCD.

  In the CCD, a charge proportional to the intensity of light incident within a predetermined time is accumulated, and the amount of the charge is used as a signal. What corresponds to the charge accumulation time for accumulating this charge is what is called an electronic shutter. By adjusting the charge accumulation time by the electronic shutter, the charge accumulation amount, that is, the signal amount can be adjusted. That is, as shown in FIG. 44, a spectral image similar to that in the case of controlling the amount of illumination light can be obtained by obtaining an RGB color image with the charge accumulation time sequentially changed.

FIG. 44 shows the case of frame sequential illumination. In this case, the upper side shows the R, G, and B illumination states, and the lower stage shows the charge accumulation time by the electronic shutter.
That is, the control of the amount of illumination light is used to obtain a normal image, and when obtaining a spectral image, it is possible to avoid saturation of the RGB color signals by changing the charge accumulation time by the electronic shutter.

  Note that the electronic shutter can also be applied to the simultaneous type.

Further, as a modification of this modification, the following may be performed.
As in the fourth embodiment, this modification uses a frame sequential method and takes advantage of this advantage. By adding weight to the charge accumulation time by electronic shutter control, the generation of spectral image data can be simplified. That is, in this modification, the CCD drive circuit 431 that can change the charge accumulation time of the CCD 21 is provided.
As an operation of this modification, as shown in FIG. 45, when each illumination light is irradiated through the RGB rotation filter 23, the charge accumulation time by the electronic shutter in the CCD 21 is changed. Here, tdr, tdg, and tdb are the charge accumulation times of the CCD 21 when the illumination light is R, G, and B. And).

For example, the F3 pseudo filter image in the case of performing the matrix processing represented by the equation (21) is obtained from an RGB image obtained by a normal endoscope,
(Equation 25)
F3 = -0.050R-1.777G + 0.829B (25)
Therefore, the charge accumulation time by RGB electronic shutter control in FIG.
tdr: tdg: tdb = 0.050: 1.777: 0.829 (26)
It can be set to be. In the matrix portion, the signal obtained by simply inverting only the R and G components and the B component are added. Thereby, the same spectral image as Example 3 can be obtained.

  According to this modification, a spectral image in which a blood vessel pattern is clearly displayed can be obtained as in the fourth embodiment. Further, in the present embodiment, as in the fourth embodiment, a surface sequential method is used to create a color image signal, and further, the charge accumulation time can be made different for each color image signal using an electronic shutter. Thereby, the matrix calculation unit 436 only needs to perform addition and difference processing, and the processing can be simplified.

Next, Embodiment 5 of the present invention will be described with reference to FIGS. FIG. 46 shows an electronic endoscope apparatus 100 according to the fifth embodiment of the present invention. In the electronic endoscope apparatus 100 of the present embodiment, for example, in the electronic endoscope apparatus 100 of FIG. 4, a part of the configuration of the main body processing apparatus 43 is changed, and for example, a normal observation image and a spectral image are displayed on the display monitor 106. It is configured so that it can be displayed simultaneously. Of course, one image is displayed by switching as described below, and a display state control means or a display control means for changing both sizes, for example, is provided.
As shown in FIG. 46, for example, the color signals R ′, G ′, B ′ output from the color signal processing unit 435 are input to the superimposing unit 181, and the color signals R ′, G ′, B ′ are input by the superimposing unit 181. Superimposed on the output signals ΣF1 to ΣF3 of the integrating units 438a to 438c. The superimposed signals are indicated by R ″, G ″, B ″. The signals R ″, G ″, B ″ are input to the white balance circuit 182, and the white balance adjusted signal Rwb from the white balance circuit 182. , Gwb, Bwb.

In FIG. 46, the output signals ΣF1 to ΣF3 of the integrating units 438a to 438c are input to the superimposing unit 181 in the solid line, but the signals that have undergone color adjustment through the color adjusting unit 440 as indicated by the two-dot chain line. Then, the data may be input to the superimposing unit 181.
These signals Rwb, Gwb, and Bwb are input to the γ correction circuit 183, become γ-corrected signals Rγ, Gγ, and Bγ, and are input to the first color conversion circuit 184. The luminance signal Y and the color difference signals RY, Converted to BY.

  Then, the luminance signal Y becomes a luminance signal Yeh whose outline is enhanced by the enhancement circuit 185, and is input to the second color conversion circuit 186 together with the color difference signals RY and BY, and the second color conversion circuit 186 Color conversion is performed to generate color signals R, G, and B.

  The color signals R, G, and B are input to the R, G, and B channels of the display monitor 106, and a corresponding image is displayed on the display monitor 106.

  In this embodiment, for example, the superimposing unit 181 includes a selection circuit that selects and outputs only one signal and an enlargement / reduction circuit 181a that performs enlargement / reduction. And the control part 42 outputs only one signal from the superimposition part 181 according to the display control signal from the keyboard 451 others by a user. Then, the selected image is displayed on the display monitor 106.

In response to the display control signal, the superimposing unit 181 enlarges the image size of the color signals R ′, G ′, B ′ output from the color signal processing unit 435 or the output signals ΣF1 to ΣF3 of the integrating units 438a to 438c. / Adjust to reduce, and superimpose and output both images. Thus, in this embodiment, display state control means or display control means for controlling an image displayed on the display monitor 106 is formed.
For example, in the display monitor 106 of FIG. 46, the normal images from the color signal R ′, G ′, and B ′ side output from the color signal processing unit 435 are the same size, and on the other hand, the integration units 438a to 438c An example is shown in which the spectral images from the output signals ΣF1 to ΣF3 are adjusted to a small size and both images are displayed simultaneously.

In this embodiment, as shown in FIGS. 47 and 48, a confirmation image is provided near the image so that it can be confirmed whether the image actually displayed on the display monitor 106 is a normal image or a spectral image. Information is explicitly displayed. In other words, when an image corresponding to each observation mode is displayed, observation mode display means for displaying the observation mode or image type is provided near the image corresponding to the observation mode. Note that the matrix calculation unit (abbreviated as MX calculation unit in FIG. 46) 436 ′ in the present embodiment incorporates the functions of the coefficient control unit 442 and the LUT 443 in FIG.
Other configurations are the same as those shown in FIG. 4, for example. In FIG. 32, the case where one observation mode is alternatively selected by switching the observation mode has been described. However, in this embodiment, two observation modes are selected simultaneously, and images obtained by the two observation modes are displayed. It corresponds to the case of displaying simultaneously.
FIG. 47 shows an image display example displayed on the display monitor 106 by the user's observation mode or display method selection control.

47A and 47B show a case where only the normal image or only the spectral image is displayed on the display monitor 106, respectively. In this case, for example, a display form similar to that shown in FIGS. 32A and 32B is employed.
FIG. 47C shows a case where a normal image is displayed in a large size, a spectral image is reduced in size, and both images are superimposed and displayed. That is, an example is shown in which a normal image is displayed on a parent screen and a spectral image is displayed on a picture-in-picture displayed on a child screen.
FIG. 47D shows a case where the sizes of the normal image and the spectral image in FIG. 47C are switched and displayed.
As described above, according to the present embodiment, the normal image and the spectral image can be displayed at the same time, so that the options for the user are further expanded and the operability is improved.

Further, in the present embodiment, even when only one image is displayed, it can be enlarged and displayed according to the resolution of the display monitor 106, so that the resolution of the display surface of the display monitor 106 is different. Even in this case, it can be displayed in an appropriate size. In addition, for example, below each image, the observation mode or image type of the image is displayed so that the user can easily confirm it. Here, the case of a normal image is explicitly indicated by NI, and the case of a spectral image is explicitly indicated by NBI.
In FIG. 47, the case of the normal display monitor 106 has been described. However, for example, it may be displayed on a display monitor having a horizontally long display surface.
FIG. 48A shows a state in which a normal image and a spectral image are simultaneously displayed on the display monitor 106 having a horizontally long display surface. Also in this case, by adjusting the display size, it becomes possible to display a relatively large size as shown in FIG.

In addition, as shown in FIG. 48B, two display monitors 106A and 106B may be prepared, and a normal image and a spectral image may be displayed on each of them. Further, the display may be switched.
Further, the spectral image to be displayed may be selected and displayed with only one wavelength, or pseudo color display using two or three spectral images as in the second embodiment.
Further, as an example of displaying the observation mode in the present embodiment, an example has been described in which an image is displayed so that it can be easily confirmed even when both images of two observation modes are displayed. Alternatively, as shown in FIGS. 32D to 32F.
The configuration for displaying the normal image and the spectral image simultaneously is not limited to that shown in FIG. 46. For example, in the configuration shown in FIG. 4, instead of the switching unit 439 that selects one image. By adopting the superimposing unit 181 in FIG. 46 that selects one image and combines (superimposes) both images, substantially the same operational effects can be obtained.

49 and 50 relate to the sixth embodiment of the present invention, FIG. 49 is a diagram showing the arrangement of the color filters, and FIG. 50 is a diagram showing the spectral sensitivity characteristics of the color filters in FIG.
Since the sixth embodiment is almost the same as the first embodiment, only different points will be described, and the same components are denoted by the same reference numerals and description thereof will be omitted.
In the present embodiment, the color filters provided in the CCD 21 are mainly different from those in the first embodiment. In the first embodiment, RGB primary color filters are used as shown in FIG. 6, whereas in this embodiment, complementary color filters are used.
As shown in FIG. 49, this complementary color filter array is composed of G, Mg, Ye, and Cy elements. The relationship between each element of the primary color filter and each element of the complementary color filter is Mg = R + B, Cy = G + B, Ye = R + G.

  In this case, all the pixels of the CCD 21 are read out, and the image from each color filter is subjected to signal processing or image processing. Further, when the equations (1) to (8) and (19) to (21) for the primary color filter are modified in the case of a complementary color filter, the following equation (33) is obtained from the following equation (27): become that way. However, the characteristics of the target narrow-band bandpass filter are the same.

［数２８］

［数２９］
ｋ_G＝（∫Ｓ（λ）×Ｈ（λ）×Ｇ（λ）ｄλ）^-1
ｋ_Mg＝（∫Ｓ（λ）×Ｈ（λ）×Ｍｇ（λ）ｄλ）^-1
ｋ_Cy＝（∫Ｓ（λ）×Ｈ（λ）×Ｃｙ（λ）ｄλ）^-1
ｋ_Ye＝（∫Ｓ（λ）×Ｈ（λ）×Ｙｅ（λ）ｄλ）^-1 …（２９）
［数３０］

［数３１］

［数３２］

［数３３］

また、図５０は、補色型色フィルタを用いた場合の分光感度特性、目標とするバンドパスフィルタ及び上記（２７）式乃至（３３）式により求められ擬似バンドパスフィルタの特性を示す。 [Equation 27]

[Equation 28]

[Equation 29]
k _G = (∫S (λ) × H (λ) × G (λ) dλ) ⁻¹
k _Mg = (∫S (λ) × H (λ) × Mg (λ) dλ) ⁻¹
k _Cy = (∫S (λ) × H (λ) × Cy (λ) dλ) ⁻¹
k _Ye = (∫S (λ) × H (λ) × Ye (λ) dλ) ⁻¹ (29)
[Equation 30]

[Equation 31]

[Formula 32]

[Equation 33]

FIG. 50 shows the spectral sensitivity characteristics when the complementary color filter is used, the target band-pass filter, and the characteristics of the pseudo band-pass filter obtained by the expressions (27) to (33).

When the complementary color filter is used, it goes without saying that the S / H circuit shown in FIG. 4 is performed not for R, G, B but for G, Mg, Cy, Ye.
Further, even when a complementary color filter is used, the matrix estimation method shown in the equations (9) to (18) can be applied. In this case, when the number of complementary color filters is four, there are four or four parts that the biological spectral reflectance assumed in the equation (14) can be approximated by three basic spectral characteristics. It becomes as follows. Accordingly, the dimension for calculating the estimation matrix is changed from 3 to 4 in accordance with this.
According to the present embodiment, as in the first embodiment, a spectral image in which the blood vessel pattern is clearly displayed can be obtained. Further, in this embodiment, it is possible to enjoy the merits of using the complementary color filter.

The present invention may be used by combining various embodiments described above, and can be modified without departing from the spirit of the present invention.
For example, for all the embodiments described above, a new pseudo band-pass filter can be created by the operator himself / herself at other timings in the clinic and applied to the clinic. That is, as shown in the first embodiment, a design unit (not shown) that can calculate and calculate matrix coefficients may be provided in the control unit 42 in FIG.
As a result, a pseudo band-pass filter suitable for obtaining a spectral image that the operator wants to know by inputting conditions via the keyboard 451 provided in the endoscope apparatus main body 105 shown in FIG. 4 is newly designed. You may make it do. In this case, the calculated matrix coefficient (corresponding to each element of the matrix “A” in the expressions (19) and (31)) is corrected to each element of the matrix “K” in the expressions (20) and (32). 4), the final matrix coefficient (corresponding to each element of the matrix “A ′” in the equations (21) and (33)) is set in the matrix calculation unit 436 in FIG. can do.

  In each of the above-described embodiments, the spectral image signal is mainly described in the case of an RGB signal, also called a color signal, as a color image signal generated from an imaging signal captured by the CCD 21, A spectral image signal may be generated from a color image signal composed of a luminance signal and a color difference signal.

  In each of the above-described embodiments and the like, the illumination light from the light source unit 31 is guided by the light guide 14 of the endoscope 101 and is guided from the distal end surface of the light guide 14 to, for example, a living tissue or the like as a subject. In the example described above, the subject is illuminated by irradiating the illumination light.

The present invention is not limited to this. For example, a light emitting diode (abbreviated as LED) is disposed at the distal end portion 103 of the endoscope 101, and the subject is illuminated with illumination light emitted from the LED. good. That is, in this case, the light source unit or the illumination unit is provided in the endoscope 101.

  A spectral image signal (spectral signal) is generated from a color image signal (biological signal) by electrical signal processing, and further provided with color tone adjustment means and coefficient switching means, so that the biological tissue to be observed is different. Even in this case, a highly reliable state can be secured, and an image can be displayed in a state where operability is good.

FIG. 1 is a conceptual diagram illustrating a signal flow when a spectral image signal is created from a color image signal according to Embodiment 1 of the present invention. FIG. 2 is a conceptual diagram illustrating integration calculation of spectral image signals according to Embodiment 1 of the present invention. FIG. 3 is an external view showing an external appearance of the electronic endoscope apparatus according to the first embodiment of the present invention. 4 is a block diagram illustrating a configuration of the electronic endoscope apparatus of FIG. 3. FIG. 5 is an external view showing an external appearance of the chopper of FIG. 4. FIG. 6 is a diagram showing an arrangement of color filters arranged on the imaging surface of the CCD shown in FIG. FIG. 7 is a diagram showing spectral sensitivity characteristics of the color filter of FIG. FIG. 8 is a configuration diagram showing the configuration of the matrix calculation unit of FIG. 4. FIG. 9 is a spectrum diagram showing the spectrum of the light source according to Example 1 of the present invention. FIG. 10 is a spectrum diagram showing a reflection spectrum of a living body according to Example 1 of the present invention. 11 is a diagram showing a layer direction structure of a living tissue observed by the electronic endoscope apparatus of FIG. FIG. 12 is a diagram for explaining a state in which illumination light from the electronic endoscope apparatus of FIG. FIG. 13 is a diagram showing the spectral characteristics of each band of white light. 14 is a first diagram showing each band image by the white light of FIG. FIG. 15 is a second diagram showing each band image by the white light of FIG. 13. FIG. 16 is a third diagram illustrating each band image by the white light of FIG. 13. FIG. 17 is a diagram illustrating spectral characteristics of a spectral image generated by the matrix calculation unit of FIG. FIG. 18 is a first diagram illustrating the spectral images of FIG. 17. FIG. 19 is a second diagram showing the spectral images of FIG. 20 is a third diagram showing the spectral images of FIG. FIG. 21 is a block diagram illustrating the configuration of the color adjusting unit in FIG. FIG. 22 is a diagram illustrating the operation of the color adjustment unit in FIG. FIG. 23 is a block diagram showing a configuration of a modification of the color adjustment unit in FIG. 4. FIG. 24 is a diagram showing spectral characteristics of a first modification of the spectral image of FIG. FIG. 25 is a diagram showing spectral characteristics of a second modification of the spectral image of FIG. FIG. 26 is a diagram illustrating spectral characteristics of a third modification of the spectral image of FIG. FIG. 27 is a flowchart showing an operation of manually switching coefficients when switching to the spectral image observation mode. FIG. 28 is a block diagram showing a configuration of a modified electronic endoscope apparatus in which coefficient switching can be performed by a centralized controller or voice input. FIG. 29 is a block diagram showing a configuration of an electronic endoscope apparatus when an ID memory is provided in an endoscope or the like. FIG. 30 is a flowchart of an operation for performing coefficient switching by a combination on the apparatus side in the case of the configuration of FIG. FIG. 31 is a flowchart showing a part of the operation when the observation mode is further displayed in the operation of FIG. 30. FIG. 32 is a diagram illustrating an example in which an observation mode is explicitly displayed when a normal image and a spectral image are displayed. FIG. 33 is a flowchart of an operation for changing and setting parameters in conjunction with switching of the observation mode in the configuration of FIG. FIG. 34 is a flowchart of a part of the operation of the modification of FIG. FIG. 35 is a block diagram illustrating a configuration of a color adjustment unit peripheral portion in an electronic endoscope apparatus according to Embodiment 2 of the present invention. FIG. 36 is a block diagram illustrating a configuration of a peripheral portion of a color adjustment unit according to a modification of the second embodiment. FIG. 37 is a block diagram illustrating a configuration of the electronic endoscope apparatus according to the third embodiment of the present invention. FIG. 38 is a block diagram illustrating a configuration of a matrix calculation unit. FIG. 39 is a flowchart for explaining operations in the third embodiment. FIG. 40 is a flowchart illustrating a part of the operation in the modified example of the third embodiment. FIG. 41 is a block diagram showing a configuration of an electronic endoscope apparatus according to Embodiment 4 of the present invention. 42 is a block diagram illustrating a configuration example of a color tone determination unit in FIG. FIG. 43 is a flowchart illustrating a part of the operation in the modified example of the fourth embodiment. FIG. 44 is an explanatory diagram showing the charge accumulation time by the electronic shutter of the CCD. FIG. 45 is an explanatory diagram showing the charge accumulation time by the electronic shutter of the CCD more specifically. FIG. 46 is a block diagram illustrating a configuration of an electronic endoscope apparatus according to Embodiment 5 of the present invention. FIG. 47 is a diagram illustrating a display example of a normal image and a spectral image on the display monitor according to the fifth embodiment. FIG. 48 is a diagram illustrating a display example of a normal image and a spectral image on a display monitor according to a modification. FIG. 49 is a diagram showing an arrangement of color filters according to Embodiment 6 of the present invention. FIG. 50 is a diagram showing spectral sensitivity characteristics of the color filter of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 41 ... Light source part 42 ... Control part 43 ... Main body processing apparatus 100 ... Electronic endoscope apparatus 101 ... Scope 102 ... Insertion part 103 ... Tip part 104 ... Angle operation part 105 ... Endoscope apparatus main body 106 ... Display monitor 141 ... Scope Switch 436 ... Matrix operation unit 440 ... Color adjustment unit 440a ... Color conversion processing circuit 441 ... Operation panel 442 ... Coefficient control unit 443 ... LUT
451 ... Keyboard

Claims (11)

A first imaging signal obtained by imaging a subject illuminated with white illumination light by a first imaging device having a plurality of broadband wavelength transmission color filters, or a plurality of different imaging signals covering a visible region. A color image signal to be displayed as a color image on the display device by performing signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in the broadband wavelength region by the second imaging device. A color image signal generation unit to generate,
Based on the first imaging signal or the second imaging signal, the color signal used to generate the color image signal or the signal processing on the color image signal is subject to illumination with illumination light in a narrow-band wavelength region. A spectral image signal generation unit that generates a spectral image signal corresponding to a narrow-band image signal obtained when the specimen is imaged;
A display color conversion unit that performs display color conversion when displaying the spectral image signal as a spectral image on a display device;
A characteristic change setting unit for changing and setting a generation characteristic of the spectral image signal in the spectral image signal generation unit, a display color change setting unit for changing and setting the display color conversion, and switching of information including an image displayed on the display device and at least one interface unit and / or for performing an instruction operation for confirmation,
Comprising
The characteristic change setting unit includes: the first imaging device or the second imaging device; and a light source unit that generates the illumination light used for imaging by the first imaging device or the second imaging device. A biological observation apparatus that automatically or manually performs the setting change of the generation characteristic by the characteristic change setting unit based on information corresponding to at least one . A first imaging signal obtained by imaging a subject illuminated with white illumination light by a first imaging device having a plurality of broadband wavelength transmission color filters, or a plurality of different imaging signals covering a visible region. A color image signal to be displayed as a color image on the display device by performing signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in the broadband wavelength region by the second imaging device. A color image signal generation unit to generate,
Based on the first imaging signal or the second imaging signal, the color signal used for generating the color image signal or the signal processing on the color image signal to be illuminated with illumination light in a narrow band wavelength region. A spectral image signal generation unit that generates a spectral image signal corresponding to a narrow-band image signal obtained when the specimen is imaged;
A display color conversion unit that performs display color conversion when displaying the spectral image signal as a spectral image on a display device;
A characteristic change setting unit for changing and setting the generation characteristic of the spectral image signal in the spectral image signal generation unit, a display color change setting unit for changing and setting the display color conversion, and switching of information including an image displayed on the display device And / or at least one of an interface unit for performing a confirmation instruction operation,
Comprising
The spectral image signal generation unit includes a coefficient storage unit that stores a plurality of coefficients for changing the generation characteristic of the spectral image signal, and the characteristic change setting unit changes the generation characteristic with respect to the coefficient storage unit. A biological observation apparatus that is a coefficient switching setting unit that switches and sets a coefficient used for setting . The plurality of coefficients stored in the coefficient storage unit include a plurality of types corresponding to the spectral reflection characteristics of the living body as the subject, a name of an observation target site in the living body, or a type of mucosal tissue of the living body. The living body observation apparatus according to claim 2, further comprising a living body coefficient . The plurality of coefficients stored in the coefficient storage unit include a plurality of feature quantity coefficients that change the generation characteristics of the spectral image signal corresponding to a plurality of different feature quantities in the living body as the subject. The living body observation apparatus according to claim 2, wherein the living body observation apparatus is characterized. The coefficient for characteristic amount is set to a coefficient for blood vessel that generates the spectral image signal for observing a blood vessel structure distributed in a depth direction from the surface of the living body. Biological observation device. A first imaging signal obtained by imaging a subject illuminated with white illumination light by a first imaging device having a plurality of broadband wavelength transmission color filters, or a plurality of different imaging signals covering a visible region. A color image signal to be displayed as a color image on the display device by performing signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in the broadband wavelength region by the second imaging device. A color image signal generation unit to generate,
Based on the first imaging signal or the second imaging signal, the color signal used for generating the color image signal or the signal processing on the color image signal to be illuminated with illumination light in a narrow band wavelength region. A spectral image signal generation unit that generates a spectral image signal corresponding to a narrow-band image signal obtained when the specimen is imaged;
A display color conversion unit that performs display color conversion when displaying the spectral image signal as a spectral image on a display device;
A characteristic change setting unit for changing and setting the generation characteristic of the spectral image signal in the spectral image signal generation unit, a display color change setting unit for changing and setting the display color conversion, and switching of information including an image displayed on the display device And / or at least one of an interface unit for performing a confirmation instruction operation,
Comprising
The display color change setting unit includes a coefficient storage unit that stores a plurality of conversion coefficients for changing characteristics of the display color conversion, and conversion of conversion coefficients used for display color conversion in the display color conversion unit. A coefficient switching setting unit that switches and sets the conversion coefficient used in
The plurality of conversion coefficients stored in the coefficient storage unit include feature amount coefficients corresponding to a plurality of feature amounts having different spectral reflection characteristics in the living body as the subject,
The feature amount coefficient is set to a blood vessel coefficient for setting a display color of the spectral image signal for observing a blood vessel structure distributed in a depth direction from the surface of the living body. Biological observation device. A first imaging signal obtained by imaging a subject illuminated with white illumination light by a first imaging device having a plurality of broadband wavelength transmission color filters, or a plurality of different imaging signals covering a visible region. A color image signal to be displayed as a color image on the display device by performing signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in the broadband wavelength region by the second imaging device. A color image signal generation unit to generate,
Based on the first imaging signal or the second imaging signal, the color signal used for generating the color image signal or the signal processing on the color image signal to be illuminated with illumination light in a narrow band wavelength region. A spectral image signal generation unit that generates a spectral image signal corresponding to a narrow-band image signal obtained when the specimen is imaged;
A display color conversion unit that performs display color conversion when displaying the spectral image signal as a spectral image on a display device;
A characteristic change setting unit for changing and setting the generation characteristic of the spectral image signal in the spectral image signal generation unit, a display color change setting unit for changing and setting the display color conversion, and switching of information including an image displayed on the display device And / or at least one of an interface unit for performing a confirmation instruction operation,
A brightness determination unit for determining whether the brightness in the spectral image signal is equal to or less than a reference value;
Comprising
A biological observation apparatus that switches generation characteristics of the spectral image signal in accordance with a determination result by the brightness determination unit . A first imaging signal obtained by imaging a subject illuminated with white illumination light by a first imaging device having a plurality of broadband wavelength transmission color filters, or a plurality of different imaging signals covering a visible region. A color image signal to be displayed as a color image on the display device by performing signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in the broadband wavelength region by the second imaging device. A narrow-band wavelength is generated by a color image signal generation unit to be generated, and signal processing for the color image signal or the color image signal used to generate the color image signal based on the first imaging signal or the second imaging signal. Spectral image signal generation that generates a spectral image signal corresponding to a narrow-band image signal obtained when imaging a subject illuminated by illumination light in a region A display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on a display device, and a setting for changing the generation characteristics of the spectral image signal in the spectral image signal generation unit. At least one of a characteristic change setting unit, a display color change setting unit for changing the display color conversion, and an interface unit for performing an instruction operation for switching and / or confirming information including an image displayed on the display device; A brightness determination unit that outputs a determination signal when the brightness in the spectral image signal is equal to or less than a reference value, and forcibly displays an image displayed on the display device based on the determination signal from the spectral image. A living body observation apparatus that switches to the color image . A first imaging signal obtained by imaging a subject illuminated with white illumination light by a first imaging device having a plurality of broadband wavelength transmission color filters, or a plurality of different imaging signals covering a visible region. A color image signal to be displayed as a color image on the display device by performing signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in the broadband wavelength region by the second imaging device. A narrow-band wavelength is generated by a color image signal generation unit to be generated, and signal processing for the color image signal or the color image signal used to generate the color image signal based on the first imaging signal or the second imaging signal. Spectral image signal generation that generates a spectral image signal corresponding to a narrow-band image signal obtained when imaging a subject illuminated by illumination light in a region A display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on the display device, and a change setting of the generation characteristic of the spectral image signal in the spectral image signal generation unit. At least one of a characteristic change setting unit, a display color change setting unit for changing display color conversion, and an interface unit for performing an instruction operation for switching and / or confirming information including an image displayed on the display device; A color tone determination unit that determines whether or not the spectral image signal corresponds to a predetermined color tone value, and switching generation characteristics of the spectral image signal according to a determination result by the color tone determination unit. A biological observation apparatus that is characterized . A first imaging signal obtained by imaging a subject illuminated with white illumination light by a first imaging device having a plurality of broadband wavelength transmission color filters, or a plurality of different imaging signals covering a visible region. A color image signal to be displayed as a color image on the display device by performing signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in the broadband wavelength region by the second imaging device. A narrow-band wavelength is generated by a color image signal generation unit to be generated, and signal processing for the color image signal or the color image signal used to generate the color image signal based on the first imaging signal or the second imaging signal. Spectral image signal generation that generates a spectral image signal corresponding to a narrow-band image signal obtained when imaging a subject illuminated by illumination light in a region A display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on the display device, and a change setting of the generation characteristic of the spectral image signal in the spectral image signal generation unit. At least one of a characteristic change setting unit, a display color change setting unit for changing display color conversion, and an interface unit for performing an instruction operation for switching and / or confirming information including an image displayed on the display device; A color tone determination unit that determines whether or not the spectral image signal corresponds to a predetermined color tone value, and the color tone determination unit includes at least a dye for staining, a residue, and bile on the subject. A specific color tone value detecting unit that detects a specific color tone value when one exists, and is displayed on the display device when the specific color tone value detected by the specific color tone value detecting unit is a predetermined amount or more; in front Biological observation apparatus according to claim forced switch over the spectral image to the color image. A first imaging signal obtained by imaging a subject illuminated with white illumination light by a first imaging device having a plurality of broadband wavelength transmission color filters, or a plurality of different imaging signals covering a visible region. A color image signal to be displayed as a color image on the display device by performing signal processing on the second imaging signal obtained by imaging the subject illuminated by the surface sequential illumination light in the broadband wavelength region by the second imaging device. A narrow-band wavelength is generated by a color image signal generation unit to be generated, and signal processing for the color image signal or the color image signal used to generate the color image signal based on the first imaging signal or the second imaging signal. Spectral image signal generation that generates a spectral image signal corresponding to a narrow-band image signal obtained when imaging a subject illuminated by illumination light in a region A display color conversion unit that performs display color conversion when the spectral image signal is displayed as a spectral image on the display device, and a change setting of the generation characteristic of the spectral image signal in the spectral image signal generation unit. At least one of a characteristic change setting unit, a display color change setting unit for changing display color conversion, and an interface unit for performing an instruction operation for switching and / or confirming information including an image displayed on the display device; The characteristic change setting unit includes a light source type / spectral characteristic detection unit that detects at least one of a difference between a type of light source and a spectral characteristic mounted on the light source unit that generates the illumination light, A biological observation apparatus that changes a generation characteristic of the spectral image signal according to a detection result by the light source type / spectral characteristic detection unit .

Images