JP2000262459A - Endoscope device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope device capable of obtaining the information on a biological function such as oxygen saturation degree with excellent accuracy by obtaining an observed image by the light of narrow bandwidth, and obtaining the observed image which is sufficiently light and less in noise when the distance of an object is large. SOLUTION: A rotary filter plate 14 has filters different in transmission bandwidth, and when a filter position control circuit 40 drives a motor 16 to move the position of the rotary filter plate 14, the transmission bandwidth of the filter to be inserted on the illumination optical path from a lamp 11 is switched. A dimming circuit 39 controls the filter position control circuit 40, and increases the operation accuracy of the information on the biological function by an operation circuit 36 between images by narrowing the transmission bandwidth of the illumination light when the image is light, or the illumination light quantity is increased by expanding the transmission bandwidth of the illumination light when the object is far and the image is dark.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope apparatus, and more particularly, to an endoscope apparatus suitable for measuring a state of a biological function by utilizing absorption characteristics of a substance in a living body with respect to visible light and infrared light. About.

[0002]

2. Description of the Related Art In recent years, an endoscope insertion portion is inserted into a body cavity to observe a digestive tract such as an esophagus, a stomach, a small intestine, or a large intestine, or a trachea such as a lung. 2. Description of the Related Art A medical endoscope apparatus capable of performing various medical treatments using an inserted treatment tool is generally used. In particular, endoscope apparatuses using an electronic imaging device such as a charge-coupled device (CCD) are widely used because they can display a moving image on a color monitor in real time and the operator who operates the endoscope has little fatigue. ing.

[0003] Recently, in addition to observing an image of a subject by ordinary visible light (hereinafter referred to as an ordinary image),
For example, by utilizing the characteristics of hemoglobin whose absorption spectrum changes according to the oxygen saturation, the reflected light from the subject is imaged, and information on biological functions such as the amount of hemoglobin contained in the subject and oxygen saturation is obtained. Endoscope devices have been proposed. In such an endoscope device, the state of biological functions can be examined non-invasively by irradiating the subject with light and imaging the reflected light, so that it is applied to efficient diagnosis of a lesion. Is expected. Here, the biological function information such as the amount of hemoglobin and the oxygen saturation is obtained by imaging a subject with a plurality of narrow-band lights having different wavelengths, and obtaining a signal level value for each pixel between a plurality of images obtained at different wavelengths. The calculation can be performed by performing the used calculation (hereinafter, referred to as an inter-image calculation). In order to perform this inter-image calculation, for example, a document “Near-infrared spectroscopy-searching inside the human body”
(Mori Tamura, "Measurement and Control," May 1997, No. 36
As described in Vol. 5, No. 5, pp. 344-348), an equation applying the Beer-Lambert rule can be used.

[0004] As an endoscope apparatus capable of observing such biological function information, for example, in Japanese Patent No. 2648494,
An endoscope apparatus capable of observing a normal image and an image indicating the oxygen saturation of hemoglobin is shown.

[0005]

However, when trying to obtain biological function information such as oxygen saturation using an endoscope apparatus conventionally used, it is difficult to observe a subtle change in oxygen saturation. However, when conducting a strict inspection such as when it is desired to obtain the absolute value of the oxygen saturation, the following problems have arisen. First, in order to obtain oxygen saturation etc. with good sensitivity, it is necessary to narrow the transmission bandwidth of the filter that limits the transmission wavelength band of illumination light or reflected light so that the change in the absorption spectrum of the subject can be captured sharply. It is advantageous. However, when the transmission bandwidth of the filter is narrowed, a sufficient light quantity cannot be obtained when viewed from a long distance, and the signal-to-noise ratio deteriorates, resulting in a problem that image noise becomes conspicuous. Further, in the conventional endoscope apparatus, multiple reflections of the illumination light reflected several times on the mucous membrane of the living body occur as shown in FIG. 14 depending on the distance to the subject and the shape of the subject. The spectrum of the illumination light emitted from the distal end of the insertion portion is different from the spectrum of the illumination light actually illuminating the desired part of the subject, that is, the region of interest, and the color reproducibility of the observed image is deteriorated. There was something to do. In particular, when observing a region of interest located at the back of an organ from a distance, the region is easily affected by multiple reflections. When a normal image of the region of interest is observed, for example, an observation image with a strong red tint may be obtained. Further, due to the effect of this multiple reflection, the obtained image may not accurately reflect the light absorption characteristics and scattering characteristics of the living mucous membrane itself in the region of interest, which is a large error factor when obtaining oxygen saturation, hemoglobin amount, and the like. Had become. Further, when obtaining information such as the oxygen saturation of hemoglobin, an image obtained by imaging an object with many wavelengths is used. Therefore, many filters for limiting the transmission wavelength band of illumination light or reflected light are provided in the endoscope apparatus. With this configuration, there is a problem that the endoscope apparatus becomes large and the expandability when trying to observe a subject with light of another wavelength is poor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to obtain an observation image using light having a narrow bandwidth, obtain biological function information such as oxygen saturation with high accuracy, and obtain an image of an object. It is an object of the present invention to provide an endoscope apparatus which can obtain a sufficiently bright observation image with little noise when the distance is long. Another object of the present invention is to provide an endoscope apparatus capable of reducing an error in obtaining biological function information such as oxygen saturation by reducing multiple reflections when illumination light is applied to a subject. Is to do. Another object of the present invention is to provide an endoscope apparatus which can be reduced in size and can be improved in scalability when additionally changing the transmission wavelength band of light.

[0007]

In order to achieve the above object, a first aspect of the present invention is to provide a first wavelength band light provided on an optical path of illumination light emitted from a light source for illuminating a subject. A first wavelength limiting means for transmitting light, and a second wavelength provided on an optical path of the illumination light, for transmitting light of a second wavelength band having a center wavelength substantially the same as the first wavelength band and having a different bandwidth. Limiting means for changing a ratio of an amount of light irradiated on the subject through the first wavelength limiting means to an amount of light irradiated on the subject through the second wavelength limiting means. And means for causing it to be provided.
According to the first aspect, it is possible to obtain an observation image using light having a narrow bandwidth and obtain biological function information such as oxygen saturation with high accuracy, and to obtain an observation image that is sufficiently bright and has little noise when a subject is far away. Make it possible. Further, claim 2 of the present invention captures the reflected light of the illumination light irradiating the subject, and uses the light absorption property of the contained substance included in the subject with respect to the wavelength of the illumination light to detect the content included in the subject. An endoscope device capable of measuring a state of a substance, characterized in that the endoscope device is provided on an optical path of the illumination light and includes a light distribution angle adjusting unit for adjusting a light distribution angle of the illumination light. . According to the second aspect, it is possible to reduce errors in obtaining biological function information such as oxygen saturation by reducing multiple reflections when the illumination light is applied to the subject.
According to a third aspect of the present invention, there is provided an optical path provided on at least one of an optical path of illumination light for illuminating a subject or an optical path of an optical image due to reflected light from the subject irradiated with the illumination light. Wavelength limiting means having a variable wavelength band,
Wavelength control means for controlling a transmission wavelength band by the wavelength limiting means. According to the third aspect, it is possible to reduce the size and improve the expandability when performing additional change of the transmission wavelength band of light.

[0008]

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

(First Embodiment) FIGS. 1 to 8 relate to a first embodiment of the present invention, FIG. 1 is an explanatory view showing the entire configuration of an endoscope apparatus, and FIG. 2 is a rotary filter plate. FIG. 3 is an explanatory view showing a spectral transmission characteristic of a filter having a full width at half maximum of 10 nm, FIG. 4 is an explanatory view showing a spectral transmission characteristic of a filter having a full width at half maximum of 30 nm, and FIG. 5 is deoxygenated hemoglobin and oxygen. FIG. 6 is an explanatory view showing the light absorption characteristics of the modified hemoglobin, FIG. 6 is an explanatory view showing the position of the filter with respect to the light flux when the subject is located near, and FIG. 7 is an explanatory view showing the position of the filter with respect to the light flux when the subject is located far away. FIG. 8 is an explanatory diagram showing the position of the filter with respect to the light flux when the subject is located at an intermediate distance.

As shown in FIG. 1, an endoscope apparatus according to the present embodiment has a light source device 1 for emitting illumination light for illuminating a subject.
And an endoscope 2 which is inserted into a body cavity or the like to capture an image of a subject to obtain an imaging signal, and an image signal obtained by the endoscope 2 can be output to a monitor-displayable video signal or an image recording device. Processor 3 for performing signal processing or the like for obtaining a digital video signal or the like, a monitor 4 for displaying the video signal obtained by the video processor 3, and an image for recording the digital video signal obtained by the video processor 3. The system includes a digital filing device 5 as a recording device and a photographing device 6 as an image recording device for recording an image reproduced from a digital video signal obtained by the video processor 3 on a photographic film.

The light source device 1 includes a lamp 11 such as a xenon lamp that emits light, and an infrared cutoff lamp provided on an illumination optical path of the lamp 11 and limiting a transmission wavelength so as to block unnecessary light and heat radiation. A filter 12, an illumination light aperture 13 provided on the illumination optical path to limit the amount of irradiation light, a rotation filter plate 14 for rotating and filters having different transmission wavelengths are sequentially inserted on the illumination light, and a rotation filter plate 14 A motor 15 for rotating and driving, a motor 16 for moving a rotary filter plate 14 in a direction perpendicular to an optical axis to switch a combination of filters inserted on the illumination light and the like, and the lamp Illumination light passing through the infrared cut filter 12, the illumination light stop 13, and the filter of the rotary filter plate 14 is condensed from 11 to a light entrance end of a light guide 23 to be described later. It is configured to include a light collecting optical system 17. By rotating the rotary filter plate 14, for example, three kinds of light of different wavelength bands, for example, three kinds of light of red, green and blue are sequentially transmitted in a time-division manner.

The endoscope 2 has an elongated insertion section 21 inserted into a body cavity or the like, and an operation section 22 provided at the base end side of the insertion section 21 for gripping and operating the endoscope 2. One end is connected to the light source device 1, and the light guide 23 guides the illumination light from the light source device 1 to the tip of the insertion portion 21 through the operation portion 22 and the insertion portion 21. The light distribution optical system 24 is provided for distributing illumination light emitted from the light guide 23 toward the subject. The light distribution optical system 24 is provided at the distal end of the insertion section 21 and forms a subject image by reflected light from the subject irradiated with the illumination light. An objective optical system 25 for imaging, and a CCD 26 as an imaging means for obtaining an image signal by capturing a subject image with a light receiving surface located at an image forming position of the objective optical system 25
A release switch 27 that is provided at a position where the operator of the operation unit 22 can easily operate, and is provided at a position where the operator of the operation unit 22 can easily operate the release switch 27 that instructs image recording on the image recording apparatus; A filter changeover switch 28 for instructing switching of a combination of filters of the rotary filter plate 14 inserted on the illumination light and the like, and a switch which is provided at a position where the operator of the operation unit 22 can easily operate and switches the type of observation image And an observation mode changeover switch 29. The CCD 26 sequentially captures, for example, three types of subject images using light of different wavelength bands in a time-division manner, and sequentially outputs, in a time-division manner, imaging signals corresponding to the subject images using the light of these different wavelength bands.

The video processor 3 includes the CCD 2
6, a pre-processing circuit 31 for extracting a video signal component from the image signal obtained from the imaging device 6, an A / D conversion circuit 32 for converting the video signal obtained by the pre-processing circuit 31 from an analog signal to a digital signal, A color balance correction circuit 33 for performing a color balance correction process or the like on the video signal output from the / D conversion circuit 32, and a video signal sequentially output from the color balance correction circuit 33 in a time-division manner for each wavelength band. A selector 34 for spatially dividing video signals for each wavelength band for output, and a selector 34 for temporarily storing video signals spatially divided and output by the selector 34 for each wavelength band, for example, for each of three wavelength bands. Memories 35a, 35b, and 35c, and images having different wavelength bands temporarily stored in the synchronization memories 35a, 35b, and 35c, respectively. By performing the arithmetic processing between the signals,
An inter-image calculation circuit 36 for obtaining and imaging biological function information such as the amount of hemoglobin and oxygen saturation, and converting, for example, an RGB video signal output from the inter-image calculation circuit 36 from a digital signal to an analog signal. D / A conversion circuit 37
a, 37b, and 37c; an encoding circuit 38 that encodes the video signal output from the inter-image arithmetic circuit 36 and outputs the video signal to the image recording apparatus; and a brightness level of the video signal obtained by the color balance correction circuit 33. A dimming circuit 3 for providing an aperture control signal to the illumination light aperture 13 so as to maintain a predetermined level.
9, the motor 16 is controlled in accordance with an instruction from the filter changeover switch 28, and the rotary filter plate 1 is controlled.
4 is provided with a filter position control circuit 40 for moving the position in the direction perpendicular to the optical axis.

As shown in FIG. 2, the rotary filter plate 14
Is a filter group 41 composed of a plurality of filters arranged on the outermost periphery centered on the rotation axis, a filter group 42 composed of a plurality of filters arranged on the intermediate periphery, and a filter group 41 arranged on the innermost periphery. And a filter group 43 including a plurality of filters.

The filter group 41 arranged at the outermost periphery
Is composed of filters 41a, 41b, and 41c that transmit light in the red, green, and blue wavelength bands, respectively.

The filter group 42 arranged on the intermediate circumference
Is a filter group 42a composed of a plurality of filters 42aa, 42ab, and 42ac arranged closer to the outer periphery and having a smaller transmission bandwidth, and a plurality of filters 42ba, 42bb, and 42bc arranged closer to the inner periphery and having a wide transmission bandwidth. , And the inner periphery of the filter group 42a and the outer periphery of the filter group 42b are arranged in contact with each other. The filters 42aa and 42ba, the filters 42ab and 42bb, and the filters 42ac and 42bc are respectively arranged in the same direction as viewed from the rotation axis.

The filter group 43 arranged at the innermost periphery
Is a filter 4 having a center wavelength of a transmission wavelength band of 430 nm.
3a, a filter 43b having a center wavelength of the transmission wavelength band of 450 nm, and a filter 43c having a center wavelength of the transmission wavelength band of 470 nm.
The full width at half maximum of each of 3b and 43c is 10 nm.

The portion of the rotary filter plate 14 other than where the filters are arranged is formed of a member that blocks light.

As shown in FIG. 3 and FIG.
Both aa and the filter 42ba have a center wavelength of the transmission wavelength band of 760 nm, and the filters 42ab and 42bb both have a center wavelength of the transmission wavelength band of 80 nm.
At 5 nm, the filter 42ac and the filter 42bc
In each case, the center wavelength of the transmission wavelength band is 840 nm.
The full width at half maximum of each of the filters 42aa, 42ab, and 42ac is 10 nm.
The full width at half maximum of each of bb and 42bc is 30 nm.
It should be noted that the characteristic curves of the filters shown in FIGS. 3 and 4 are given the same reference numerals as in FIG. 2 for the filters corresponding to these characteristic curves.

Next, the operation of the present embodiment will be described. The lamp 11 of the light source device 1 emits light in a wavelength region including a visible region and a near-infrared region, and the light is emitted by an infrared cut filter 12, an illumination light stop 13, and a rotary filter plate 1.
4 and enters the light guide 23 of the endoscope 2.

At this time, the infrared cut filter 12
Attenuates light of wavelengths below 80 nm and above 900 nm,
Unnecessary heat and light applied to each filter on the rotary filter plate 14 are blocked.

The illumination light diaphragm 13 limits the amount of light emitted from the light source device 1 in accordance with a diaphragm control signal supplied from a dimming circuit 39 of the video processor 3,
The saturation is not caused in the image captured in D26.

During normal observation, the outermost filter group 41 is inserted on the optical axis at the time of normal observation, and the filters 41a, 41b, and 41c are rotated on the optical path by the motor 15 to rotate at a predetermined speed. Are sequentially inserted in a time-division manner, and red, green, and blue lights are sequentially transmitted in a time-division manner.
Further, at the time of hemoglobin observation for observing the oxygen saturation and the amount of hemoglobin, the motor 16 moves the rotary filter plate 14 in a direction perpendicular to the optical axis in accordance with a filter position control signal from the filter position control circuit 40, so that Instead of the outer peripheral filter group 41, an intermediate peripheral filter group 42
And the innermost filter group 43 is inserted on the optical axis. When the filter group 42 of the intermediate circumference is inserted on the optical path, 760 nm, 805 nm,
Light having a center wavelength of 840 nm is sequentially transmitted in a time division manner, and when the innermost filter group 43 is inserted on the optical path, light having a center wavelength of 430 nm, 450 nm, and 470 nm is sequentially transmitted in a time division manner. From the light source device 1.

FIG. 5 shows the molecular extinction coefficient, that is, the absorbance, of each of the oxygenated hemoglobin (also referred to as oxyhemoglobin) and deoxygenated hemoglobin (also referred to as deoxyhemoglobin), which are pigments contained in the blood of the living body as the subject. Shown in contrast. Note that oxygenated hemoglobin is hemoglobin bound to oxygen, deoxygenated hemoglobin is hemoglobin not bound to oxygen, and in the present application, oxygenated hemoglobin and deoxygenated hemoglobin are collectively referred to as hemoglobin. Call. The oxygen saturation of hemoglobin is calculated by obtaining the amount of oxygenated hemoglobin relative to the amount of total hemoglobin. FIG.
As can be seen, the wavelengths of 805 nm and 450 nm are
This is a wavelength at which there is almost no difference in absorbance between oxygenated hemoglobin and deoxygenated hemoglobin.
30 nm is a wavelength at which deoxygenated hemoglobin has a higher absorbance, and 840 nm and 470 nm are wavelengths at which oxygenated hemoglobin has a higher absorbance. As described above, by selecting the liquid length at which the absorbance is reversed between oxygenated hemoglobin and deoxygenated hemoglobin, the obtained video signal of each wavelength band is assigned to, for example, each color of red, green, and blue of the monitor 4, and the image is formed. When observing, the change in oxygen saturation can be easily recognized as a change in the color of an image. Also, the shorter the wavelength, the greater the absorption of hemoglobin, so the longer the wavelength, the better the light transmittance to the living body. Therefore, 760 nm, 8
When light of long wavelengths such as 05 nm and 840 nm is used, information on the oxygen saturation and hemoglobin amount in the relatively deep mucosa can be obtained, and 430 nm, 450 nm and 47 nm can be obtained.
When light having a short wavelength such as 0 nm is used, information on the oxygen saturation and hemoglobin amount of the mucosal surface layer can be obtained relatively.

The filter group 4 inserted on the optical path
Selection of 1, 42, and 43 is performed by the filter position control circuit 40 supplying a filter position control signal to the motor 16 in accordance with an instruction from the filter changeover switch 28. At this time, when the outermost filter group 41 or the innermost filter group 43 is inserted on the optical path, the position of the rotary filter plate 14 with respect to the optical axis is kept constant, but the intermediate filter group 42 is maintained. Is inserted in the optical path, the motor 16 is controlled by the filter position control signal from the filter position control circuit 40, the position of the rotary filter plate 14 with respect to the optical axis moves, and the light transmitted therethrough is described later. Is substantially changed.

The illumination light incident on the light guide 23 of the endoscope 2 is guided to the distal end of the insertion section 21 of the endoscope 2 and is irradiated from the light distribution optical system toward a subject such as a digestive tract. You. Then, the subject image formed by the reflected light scattered and reflected by the subject is formed on the light receiving surface of the CCD 26 by the objective optical system 25. The CCD 26 is driven in synchronization with the rotation of the rotary filter plate 14, and corresponds to the illumination light of each wavelength band which the rotary filter plate 14 sequentially transmits in a time-division manner.
A subject image is sequentially captured in a time-division manner by reflected light in each wavelength band, and an image signal corresponding to each wavelength band is sequentially provided to the video processor 3 in a time-division manner.

The image signal input to the video processor 3 is first input to a pre-processing circuit 31. The pre-processing circuit 31 performs a CDS (correlation double sampling) process or the like on the image signal to convert a video signal component. Extract. The video signal obtained by the pre-processing circuit 31 is A / D
The conversion circuit 32 converts the analog signal to a digital signal, and the color balance correction circuit 33 performs a color balance correction process. At this time, the color balance correction circuit 33 switches the color balance correction coefficient according to the position of the rotary filter
Even if the four filter groups 41, 42, 43 are switched,
Processing is performed to always maintain an appropriate color balance.

The video signal output from the color balance correction circuit 20 is spatially divided for each wavelength band by the selector 34, and the synchronization memories 35a, 35b,
35c and temporarily stored. At this time, at the time of normal observation in which the filter group 41 is inserted in the illumination light path, video signals corresponding to the red, green, and blue wavelength bands obtained by sequentially inserting the filters 41a, 41b, and 41c in the illumination light path are obtained. They are temporarily stored in the synchronization memories 35a, 35b, and 35c, respectively. Further, at the time of hemoglobin observation when the filter group 42 is inserted in the illumination light path, video signals corresponding to the wavelength bands having the center wavelengths of 760 nm, 805 nm, and 840 nm are output from the synchronization memories 35a, 35b,
35c are temporarily stored. Filter group 4
When observing hemoglobin when 3 is inserted into the illumination optical path, the center wavelength is 430 nm, 450 nm, and 470 nm.
The video signal corresponding to the wavelength band of
35b and 35c respectively temporarily store them. Then, the video signals of the images for the respective wavelength bands stored in the synchronization memories 35a, 35b, 35c are read out at the same time and synchronized.

The images synchronized by the synchronization memories 35a, 35b, 35c are supplied to an inter-image operation circuit 36.
The image-to-image calculation circuit 36 includes a filter changeover switch 28
And performs processing in accordance with an instruction from the observation mode changeover switch 29, and outputs, for example, an RGB video signal. The RGB type video signal is supplied to a D / A conversion circuit 37.
a (37b, 37c), R (red), G (green), B
Each digital component of (blue) is converted from a digital signal into an analog signal, and supplied to the monitor 4. That is, among the video signals output from the inter-image calculation circuit 36, the R signal corresponds to red on the monitor 4, the G signal corresponds to green on the monitor 4, and the B signal corresponds to blue on the monitor 4. . During normal observation, that is, when the filter group 41 is selected by the filter changeover switch 28, the inter-image calculation circuit 36
Outputs the video signals read from the synchronization memories 35a, 35b, and 35c as R signals, G signals, and B signals as they are. Therefore, the video signal obtained corresponding to the illumination light of each color of red, green, and blue is rendered corresponding to the red, green, and blue of the monitor 4 as it is.

At the time of hemoglobin observation, that is, the filter group 42 or the filter group 4
3 is selected, the inter-image calculation circuit 36
A first operation mode for directly outputting an input video signal in accordance with an instruction from the observation mode changeover switch 29, a second operation mode for obtaining an oxygen saturation image indicating an oxygen saturation distribution, and a hemoglobin amount distribution Is performed in any one of the third operation modes for obtaining the hemoglobin amount image indicating the following.

In the first operation mode, the inter-image operation circuit 3
6 outputs the video signals read from the synchronization memories 35a, 35b, and 35c as R signals, G signals, and B signals as they are, so that the image components corresponding to the illumination light in each wavelength band are changed to red, It is assigned to each of the green and blue color components and rendered. For example, when the filter group 42 is selected, the center wavelengths are 760 nm, 805 nm, and 84 nm.
When the image components corresponding to the illumination light of each wavelength band of 0 nm are assigned to the red, green, and blue color components of the monitor 4 and drawn, and when the filter group 43 is selected,
The image components corresponding to the illumination light of each wavelength band having a center wavelength of 430 nm, 450 nm, and 470 nm
It is assigned to each of the green and blue color components and rendered. Accordingly, in the first operation mode, an image in which the oxygen saturation is higher in red than blue and the oxygen saturation is lower in blue than red is displayed on the monitor 4, and the oxygen saturation is intuitively displayed. The distribution can be known.

In the second operation mode, the inter-image operation circuit 3
6 calculates the amount of hemoglobin at the position of each pixel,
A video signal in which the color and luminance of each pixel are edited to represent the amount of hemoglobin is output. This allows the monitor 4 to observe the amount of hemoglobin at the position of each pixel.

In the third operation mode, the inter-image operation circuit 3
Reference numeral 6 calculates the oxygen saturation at the position of each pixel, and outputs a video signal in which the color and luminance of each pixel are edited to indicate the oxygen saturation. This allows the monitor 4 to observe the oxygen saturation at the position of each pixel.

The video signal output from the inter-image calculation circuit 36 is subjected to a conversion for correcting the gamma characteristic of the monitor 4 by a gamma correction circuit (not shown) if necessary, and then converted to a D / A conversion circuit 37a. , 37b, 37c.

The video signal output from the inter-image operation circuit 36 is not only given to the monitor 4 via D / A conversion circuits 37a, 37b and 37c, but is also encoded by the encoding circuit 38, It is provided to a digital filing device 5 and a photographing device 6 which are recording devices. Recording of the video signal to the image recording device is performed by the release switch 27.
Is operated in response to an image recording instruction signal given from the release switch 27.

The light control circuit 39 detects the brightness of the image from the signal level of the video signal obtained by the color balance correction circuit 33, and outputs an aperture control signal to keep the brightness of the obtained image substantially constant. 13 to control the amount of light emitted from the light source device 1, and when the filter group 42 on the intermediate circumference of the rotary filter plate 14 is inserted on the illumination optical path, the filter position is adjusted according to the brightness of the image. The filter position control signal is transmitted to the motor 1 through the control circuit 40.
6, the position of the rotating filter plate 14 in the direction perpendicular to the optical axis is controlled in order to adjust the positional relationship between the filter group 42 on the intermediate circumference and the luminous flux of the illumination light as described below. First, when the image of the subject is short and the image is sufficiently bright, as shown in FIG. 6, the motor 16 is driven and controlled so that the luminous flux of the illumination light passes through the filter group 42a having a full width at half maximum of 10 nm. Fourteen positions are adjusted. By narrowing down the wavelength bandwidth of the illumination light in this manner, the signal of each pixel included in the video signal obtained corresponding to the illumination light having a wavelength at which the difference in absorbance between oxygenated hemoglobin and deoxygenated hemoglobin is increased. The level accuracy becomes higher, and the oxygen saturation and hemoglobin amount can be obtained with high accuracy.

When the object is far away and strong illumination light is required, as shown in FIG. 7, the rotating filter plate 14 is rotated so that the luminous flux of the illumination light passes through a filter group 42b having a full width at half maximum of 30 nm. Is adjusted, and the amount of light irradiated to the subject increases. By widening the wavelength bandwidth of the illumination light and increasing the amount of illumination in this way,
Even with a distant subject, an observation image with sufficient brightness and little noise can be obtained. When the distance to the subject is an intermediate distance, as shown in FIG. 8, a part of the luminous flux of the illumination light passes through a filter group 42a having a full width at half maximum of 10 nm, and a part of the light bundle 42b has a full width at half maximum of 30 nm. Pass through. As described above, the amount of light passing through the filter group 42a having a full width at half maximum of 10 nm and the full width at half maximum are obtained by moving the rotary filter plate 14 to a position where the luminous flux of the illumination light straddles the filter groups 42a and 42b. The ratio of the amount of light passing through the 30 nm filter group 42b is adjusted, and the substantial wavelength bandwidth of the illumination light applied to the subject is adjusted. When the filter group 42 of the intermediate circumference is inserted in the illumination light path, the illumination light diaphragm 13 is rotated by the rotating filter plate 1.
The light control circuit 39 may control the light control circuit 39 so that the light control circuit 39 is used as an auxiliary when a quick dimming change that cannot be dealt with by the movement of 4 is required, or when adjusting the brightness of an image with excessive brightness.

As described above, according to the present embodiment, it is possible to obtain an observation image using light having a narrow bandwidth, obtain biological function information such as oxygen saturation with high accuracy, and to obtain an image when an object is far away. The effect is obtained that a sufficiently bright observation image with little noise can be obtained.

The endoscope apparatus of the present embodiment sequentially irradiates the subject with illumination light of each wavelength band in a time-division manner during normal observation and observation of biological function information such as oxygen saturation and hemoglobin amount. Although the field-sequential illumination is performed, the present invention is not limited to this. For example, during normal observation, simultaneous illumination may be performed to simultaneously irradiate the subject with illumination light of each wavelength band. In this case, at the time of normal observation, the rotary filter plate 14 is removed from the illumination optical path, and observation is performed in a state where, for example, a mosaic filter (not shown) for color separation is inserted on the reflection optical path. The plate 14 may be inserted on the illumination optical path and observed in a plane-sequential manner. Further, for example, the full width at half maximum is 10 nm.
The means for adjusting the ratio of the amount of illumination light transmitted through the narrow wavelength band filter to the amount of illumination light transmitted through the wide wavelength band filter having, for example, a full width at half maximum of 30 nm is spatially different from each other as in the present embodiment. The filters are not limited to those configured to change the area through which the illumination light passes, but may be configured to change the time required to pass through each filter, for example. The wavelength band of the illumination light is, for example, 550.
Three wavelength bands around -600 nm may be used,
Biological function information such as oxygen saturation and hemoglobin amount may be calculated by solving simultaneous equations using not only three wavelength bands but also four or more wavelength bands. When the release switch 27 is operated while the oxygen saturation image or the hemoglobin amount image is displayed on the monitor 4, the position of the rotary filter plate 14 is automatically moved, and the normal image is also displayed. It may be recorded in an image recording device. Further, instead of controlling the amount of illumination by the illumination light aperture 13, the exposure amount may be controlled by using the electronic shutter function of the CCD. In addition, when calculating biological function information such as oxygen saturation and hemoglobin amount, the image is frozen by performing an arithmetic operation on the frozen still image by using a microcomputer, and the image is configured. The inter-operation circuit may be downsized. Also,
Instead of a filter that transmits light of a predetermined wavelength, a mirror that reflects light of a predetermined wavelength band may be used. Further, the imaging means is not limited to the configuration disposed in the endoscope insertion section, and may be configured to be detachably attached to an eyepiece of an optical endoscope (not shown).

(Second Embodiment) FIGS. 9 to 15 relate to a second embodiment of the present invention. FIG. 9 is an explanatory view showing the entire configuration of an endoscope apparatus, and FIG. FIG. 11 is an explanatory diagram showing the configuration of the visible light switching filter, FIG. 11 is an explanatory diagram showing the spectral transmission characteristics of the visible light transmitting filter and the infrared light transmitting filter, FIG. 12 is an explanatory diagram showing the configuration of the rotating filter plate, and FIG.
FIG. 14 is an explanatory diagram showing spectral transmission characteristics of a filter, a G filter, and a B filter. FIG. 14 is an explanatory diagram showing a state in which multiple reflected light is applied to a region of interest. FIG. FIG. In the present embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

As shown in FIG. 9, in the endoscope device of the present embodiment, the light source device 1 (see FIG. 1) of the first embodiment, the endoscope 2 (see FIG. 1), Video processor 3
Instead of (see FIG. 1), a light source device 51 and an endoscope 52
And a video processor 53 are provided.

The light source device 51 is different from the light source device 1 of the first embodiment (see FIG. 1) in that the infrared cut filter 12 (see FIG. 1) is replaced with a lamp 11 by a rotating position. Infrared / visible switching filter 61 for selectively transmitting the visible light component and the infrared light component of the illumination light emitted from
And a motor 62 for rotating the infrared / visible switching filter 61 is provided. A rotary filter plate 63 is provided instead of the rotary filter plate 14 (see FIG. 1).
(See FIG. 1).

As shown in FIG. 10, the infrared / visible switching filter 61 includes a visible light transmitting filter 61a that transmits visible light and an infrared light transmitting filter 61b that transmits infrared light.
The visible light transmitting filter 6
The spectral transmission characteristics of each of 1a and the infrared light transmission filter 61b are as shown in FIG. This infrared
The visible light transmission filter 61a and the infrared light transmission filter 61b are selectively inserted into the illumination light by rotating the visible light switching filter 61 around the rotation axis.

As shown in FIG. 12, the rotary filter plate 63 of the present embodiment has an R filter 63a, a G filter 63b, and a G filter 63b which respectively transmit red, green, and blue light in the visible light region.
The rotation filter plate 63 is rotated around the rotation axis so that the R filter 63a, the G filter 63b, and the B filter 63c are sequentially inserted on the illumination optical path. Has become. In addition,
Unlike the rotary filter plate 14 of the first embodiment (see FIG. 1), the position of the rotary filter plate 63 of the present embodiment is fixed in the direction perpendicular to the optical axis. As shown in FIG. 13, the R filter 63a, the G filter 63b, and the B filter 63c respectively have wavelengths of visible light of red, green, and blue, as well as infrared light of 660 nm ± 15 nm, respectively.
The wavelength bands of 805 nm ± 15 nm and 915 nm ± 15 nm are also transmitted.

As shown in FIG. 9, the endoscope 52 of the present embodiment is the same as the endoscope 2 of the first embodiment (see FIG. 1).
A light distribution optical system having a liquid crystal lens 71 capable of electrically controlling the focal length is provided in place of the light distribution optical system 24 (see FIG. 1).

The video processor 53 according to the present embodiment
By driving the motor 62 in place of the filter position control circuit 40 (see FIG. 1) of the video processor 3 (see FIG. 1) of the first embodiment, the transmission wavelength of the infrared / visible switching filter 61 is changed. A filter switching circuit 82 that outputs a filter switching signal for switching a band is provided.

Next, the operation of the present embodiment will be described. Illumination light in a wavelength region including a visible light region and a near-infrared region is emitted from the lamp 11 of the light source device 51.
Then, the light passes through the rotary filter plate 63 and the condenser optical system 17 and is incident on the light incident end of the light guide 23 of the endoscope 52. At this time, the infrared / visible switching filter 61 is rotated and driven by the motor 62 controlled by the filter switching circuit 82, and then held at the rotating position, thereby the visible light transmitting filter 61a and the infrared light transmitting filter 61a. Either 61b is inserted on the optical path. At this time, the filter switching circuit 82 operates according to an instruction from the filter switching switch 28.

The illumination light stop 13 restricts the amount of light emitted from the light source device 1 in the same manner as in the first embodiment so that the image picked up by the CCD 26 does not become saturated. I do. The rotary filter plate 63 is driven to rotate by the motor 15, so that when the visible light transmitting filter 61a is inserted into the illumination light path,
Green and blue lights are sequentially transmitted, and when the infrared light transmission filter 61b is inserted in the illumination light path, red, green,
Instead of blue, 660 nm ± 15 nm, 805 nm ± 1
Light in the wavelength band of 5 nm, 915 nm ± 15 nm is sequentially transmitted. As described in the first embodiment with reference to FIG. 5, 805 nm is a wavelength at which the difference in absorbance between oxygenated hemoglobin and deoxygenated hemoglobin is small, and 660 nm is the wavelength of deoxygenated hemoglobin. The wavelength at which the absorbance is higher is 915 nm, and the wavelength of 915 nm is the wavelength at which the absorbance of oxygenated hemoglobin is higher. By using these wavelengths, the oxygen saturation and the amount of hemoglobin can be calculated.

As described above, the visible light transmitting filter 6
Normal observation is performed when 1a is inserted into the illumination light path, and hemoglobin observation is performed when the infrared light transmission filter 61b is inserted into the illumination light. At this time, in the same manner as in the first embodiment, during the hemoglobin observation, the inter-image calculation circuit 36 changes the first operation mode and the second operation mode in accordance with an instruction from the observation mode switch 29.
And the operation mode of the third operation mode.

The illuminating light from the light source device 51 is guided by the light guide 23 and is emitted from the light distribution optical system having the liquid crystal lens 71 toward the subject. At this time, the focal length of the liquid crystal lens 71 changes in accordance with a change in the driving voltage controlled by the liquid crystal lens driving circuit 81. The light distribution angle is changed by the lens 71, and the irradiation range on the subject is adjusted.

At this time, if the distribution angle of the illumination light to the subject is not adjusted, as shown in FIG. 14, when the distribution angle of the illumination light to the region of interest of the subject is excessive,
The multiple reflection light generated by the reflection of the illumination light on the living body mucous membrane is radiated to the region of interest, thereby irradiating the region of interest with light having a spectrum different from the spectrum that should be radiated to the region of interest. The measurement accuracy in the second operation mode and the third mode is deteriorated.

Therefore, in the present embodiment, the liquid crystal lens driving circuit 81 controls the liquid crystal lens 71 according to the state of the filter changeover switch 28 and the observation mode changeover switch 29 as described below. For example, in the first operation mode at the time of normal observation and hemoglobin observation, as shown by solid arrows in FIG. 15, the light distribution angle of the illumination light is widened, and the illumination light irradiates the entire field of view that can be imaged by the CCD 26. Is done. In the second operation mode and the third operation mode, FIG.
As shown by the broken line arrow in 5, the light distribution angle of the illumination light becomes narrow, and the spread of the illumination light over the region of interest is suppressed from becoming excessive. In this way, the light distribution angle of the illumination light is adjusted, and the illumination range is narrowed, so that most of the illumination light applied to the region of interest becomes direct light from the endoscope,
The multiple reflection light to the region of interest is reduced, and an error factor due to multiple reflection, which is a problem when obtaining the oxygen saturation and the amount of hemoglobin, is prevented, and an accurate oxygen saturation and the amount of hemoglobin can be obtained.

As described above, according to the present embodiment, errors in obtaining biological function information such as oxygen saturation are reduced by reducing multiple reflections when illumination light is applied to a subject. The effect that it can be obtained is obtained.

In the present embodiment, the liquid crystal lens 71 is provided to change the light distribution angle of the illumination light.
Not limited to such a configuration, an aperture that limits the illumination range may be provided in, for example, the light distribution optical system, and the light distribution angle may be mechanically moved, for example, by moving a lens that configures the light distribution optical system. You may comprise the means to adjust. Also, when the illumination range is reduced, the image is enlarged optically or electronically in conjunction with this, and control is performed so that a portion not irradiated with illumination light or a portion with dark light distribution is not displayed on a monitor or the like. You may. In addition, the subject and the endoscope are designed so that the irradiation light is narrowed down in the case of a distant view that is easily affected by the multiple reflection light, and that the irradiation light is broadened in the case of a close proximity that is not easily affected by the multiple reflection light. The liquid crystal lens 71 may be controlled according to the distance of the mirror tip. In the present embodiment, the change of the illumination range is automatically performed in accordance with the switching of the infrared / visible switching filter 61 and the switching of the observation mode, that is, the operation mode of the inter-image calculation circuit 36. This may be performed by the user pressing a switch when necessary. When observation is performed using the infrared light transmitting filter 61b, a bright image may be obtained by increasing the exposure amount by reducing the rotation speed of the rotary filter plate 63 and lengthening the exposure time of the CCD 26. . In addition, the endoscope of the present embodiment obtains oxygen saturation and hemoglobin amount as biological function information from a captured image, but is not limited thereto.For example, an index value of the hemoglobin amount contained in a living mucous membrane may be used. A certain hemoglobin index (IHb) or the like may be obtained.

(Third Embodiment) FIGS. 16 and 17 relate to a third embodiment of the present invention. FIG. 16 is an explanatory diagram showing the entire configuration of an endoscope apparatus, and FIG. 3 is a timing chart showing the operation of the CCD. In the present embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

As shown in FIG. 16, the endoscope device of the present embodiment is different from the endoscope device of the first embodiment (see FIG. 1) in that the light source device 1 (see FIG. 1). ), A light source device 101 is provided, and instead of the video processor 3 (see FIG. 1), a video processor 103 (see FIG. 1) is provided.
Is provided.

The light source device 101 of the present embodiment is different from the light source device 1 of the first embodiment (see FIG. 1) in that the rotary filter plate 14 (see FIG. 1) and the motor 15 (see FIG. 1) are used. Instead of the motor 16 and the motor 16 (see FIG. 1), a wavelength variable filter 111 having a variable transmission wavelength band of the illumination light is provided on the illumination optical path. The tunable filter 111 is configured by stacking liquid crystal cells, and by changing the voltage applied to the liquid crystal,
1 can be instantaneously changed in wavelength. Since the wavelength tunable filter 111 can select an arbitrary wavelength as a transmission wavelength, it is sometimes called a liquid crystal tunable filter. For details on the wavelength tunable filter, for example,
Document "Tunable filter using liquid crystal" (Tatsuo Uchida, "Applied Physics", 1995, Vol. 64, No. 5, 45)
1-455).

The video processor 103 according to the present embodiment
Is different from the first embodiment (see FIG. 1) in that a wavelength control circuit 112 for controlling the tunable filter 111 is used instead of the filter position control circuit 40 (see FIG. 1).
Is provided.

Next, the operation of the present embodiment will be described. The wavelength control circuit 55 performs any one of three filter control operations, a filter control operation for normal observation, a filter control operation for deep hemoglobin observation, and a filter control operation for surface hemoglobin observation, according to the switching of the filter changeover switch 28. Control operation.

When the filter control operation for normal observation is selected by the filter changeover switch 28, the wavelength variable filter 111 controlled by the wavelength control circuit 112
Is light in a wavelength band having central wavelengths of 620 nm, 540 nm, and 450 nm, that is, red, green,
Light in the blue wavelength band is sequentially transmitted. Illumination light of each wavelength band sequentially transmitted through the wavelength tunable filter 111 is applied to the subject, and the subject image due to the reflected light is sequentially captured by the CCD 26. As described in the first embodiment, red,
Video signals including images corresponding to the respective colors of green and blue are temporarily stored in the synchronization memories 35a, 35b and 35c and synchronized, and displayed on the monitor 4 as normal images. Note that, at this time, the reading of the pixel data signal from the CCD 26 is performed during a transition period during which the wavelength tunable filter 111 switches the transmission wavelength, as shown in FIG.

When the filter control operation for deep hemoglobin observation is selected, the wavelength tunable filter 11
1 sequentially transmits light in a wavelength band having center wavelengths of 760 nm, 805 nm, and 840 nm, respectively.
The video signal corresponding to the illumination light of each wavelength band is temporarily stored in the synchronization memories 35a, 35b, and 35c and synchronized, and operates between the images in the operation mode designated by the observation mode switch 29. The image generated by 36 is displayed on the monitor 4.

When the filter control operation for observing the surface hemoglobin is selected, the wavelength tunable filter 11
1 sequentially transmits light in a wavelength band having center wavelengths of 430 nm, 450 nm, and 470 nm, respectively. The video signal corresponding to the illumination light of each wavelength band is
The same processing as in the case of the filter control operation for deep hemoglobin observation is performed and displayed on the monitor 4.

As described above, according to the present embodiment, the rotary filter plate 14 (see FIG. 1) having many filters as in the first embodiment, and the rotary filter plate 14 is rotated. A filter, which is generally composed of a large number of large members, such as a motor 15 (see FIG. 1) and a motor 16 (see FIG. 1) that moves the position of the rotary filter plate 14, is replaced with a wavelength tunable filter 111. Therefore, the number of parts is reduced, and the size of the light source device constituting the endoscope device is reduced. Further, since the wavelength band transmitted by the wavelength tunable filter 111 is controlled by a signal from the wavelength control circuit 112, for example, when an additional change of the transmission wavelength band is performed, a mechanical change operation is reduced, and this transmission wavelength is reduced. Extensibility when performing additional change of the band is improved. Therefore, according to the present embodiment, it is possible to obtain an effect that the endoscope apparatus can be reduced in size and expandability when an additional change of the light transmission wavelength band is performed can be improved.

In the present embodiment, the wavelength tunable filter 111 is incorporated in the light source device 101, but the present invention is not limited to such a configuration, and the illumination light at the tip of the insertion section 21 of the endoscope 2 is not limited to this configuration. A tunable filter may be incorporated on a road or at a position such as the front of the CCD 26. By incorporating a tunable filter in front of the CCD 26, the effect of heat due to light received by the tunable filter can be reduced.
In addition, by alternately irradiating the subject with light in the wavelength band for deep hemoglobin observation and the wavelength band for surface hemoglobin observation, the hemoglobin information of the mucosal surface layer and the deep layer is simultaneously displayed on the monitor, or the wavelength for normal observation is used. Even if the normal image and the oxygen saturation distribution image or the blood flow distribution image obtained from the hemoglobin distribution are simultaneously displayed on the monitor by alternately irradiating the subject with light in the wavelength band for the hemoglobin observation and the band. Good. Further, the wavelength of the currently selected filter may be displayed on the monitor. Further, the wavelength control circuit 112 may be configured using a microprocessor, for example, so that a user can set and observe an arbitrary wavelength. Also, the wavelength tunable filter 111 and the rotary filter plate as described in the first embodiment are configured to be selectively inserted on the illumination optical path, and are observed using the rotary filter plate during normal observation, and are used for hemoglobin observation. The tunable filter 111 may be used. In addition, the oxygen saturation and hemoglobin amount of hemoglobin are calculated from video signals obtained by sequentially irradiating light of three wavelength bands to a subject.
Light in more than one wavelength band may be used. In addition, light in a wavelength band for obtaining the oxygen saturation of hemoglobin and the amount of hemoglobin is used as illumination light, but is not limited thereto, and by selecting an appropriate wavelength band, oxygen metabolism of cytochrome and myoglobin is obtained. For this purpose, an endoscope device may be applied. Further, by providing a mosaic filter for color separation on the front surface of the CCD 26, simultaneous imaging is performed to simultaneously image each wavelength band during normal observation, and the wavelength variable filter 111 is used during biological function information measurement such as hemoglobin observation. , The image may be observed by performing a frame sequential imaging.

It should be noted that the present invention is not limited to only the above-described embodiment, but can be variously modified without departing from the gist of the invention.

[Supplementary note] (Supplementary note 1-1) A first wavelength limiting means provided on an optical path of illumination light emitted from a light source for illuminating a subject and transmitting light in a first wavelength band; A second wavelength limiter provided on an optical path of the illumination light and passing light of a second wavelength band having a center wavelength substantially the same as the first wavelength band and having a different bandwidth; and the first wavelength limiter Means for changing the ratio of the amount of light passing through the second wavelength limiter and irradiating the subject to the subject. Endoscope device.

(Additional Item 1-2) The endoscope apparatus according to additional item 1-1, wherein the first wavelength limiting means and the second wavelength limiting means are constituted by optical filters. .

(Additional Item 1-3) The first wavelength limiting means and the second wavelength limiting means are arranged so as to be in contact with each other.

(Additional Item 1-4) The endoscope apparatus according to Additional Item 1-3, wherein the first wavelength limiting unit, the second wavelength limiting unit, and the optical axis of the illumination light are different from each other. The ratio is changed by adjusting the position in the direction perpendicular to the optical axis.

(Additional Item 1-5) The endoscope apparatus according to Additional Item 1-1, further comprising fixing means to which the first wavelength limiting means and the second wavelength limiting means are attached and fixed. The ratio is changed by adjusting the position of the fixing means and the optical axis of the illumination light in the direction perpendicular to the optical axis.

(Additional Item 1-6) The endoscope apparatus according to Additional Item 1-5, further comprising a moving means for moving a position of the fixing means in a direction perpendicular to the optical axis. (Additional Item 1-7) In the endoscope apparatus according to Additional Item 1-6, the moving means is configured by a motor.

(Additional Item 1-8) The endoscope apparatus according to Additional Item 1-5, wherein the fixing means is a rotatable rotating body, and a motor for rotating the rotating body is provided. Was.

(Additional Item 1-9) The endoscope apparatus according to Additional Item 1-8, wherein the first wavelength limiting means and the second wavelength limiting means are arranged concentrically with each other. .

(Additional Item 1-10) The endoscope apparatus according to Additional Item 1-8, wherein the first wavelength limiting means and the second wavelength limiting means are rotated by rotation of the rotating body. Light of a plurality of wavelength bands is selectively and sequentially transmitted.

(Additional Item 1-11) The endoscope apparatus according to Additional Item 1-6, further comprising control means for driving and controlling the moving means.

(Additional Item 1-12) The endoscope apparatus according to Additional Item 1-11, further comprising input means for instructing the control means on the position of the fixing means.

(Additional Item 1-13) The endoscope apparatus according to Additional Item 1-11, wherein the control means is configured to control brightness of an image included in a video signal obtained by capturing an image of the subject. The driving means controls the movement of the moving means.

(Additional Item 1-14) The endoscope apparatus according to Additional Item 1-13, wherein: an image pickup means for picking up an image of the subject; and a video signal is obtained from an image pickup signal obtained by the image pickup means. Video signal processing means for performing video signal processing.

(Additional Item 1-15) In the endoscope apparatus according to Additional Item 1-14, the control means is provided in the same housing as the video signal processing means.

(Additional Item 1-16) The endoscope apparatus according to Additional Item 1-11, wherein an image pickup means for picking up an image of the subject, and a video signal is obtained from an image pickup signal obtained by the image pickup means. A video signal processing unit for performing video signal processing, and a calculation unit for performing a calculation to obtain distribution information of a substance contained in the subject from a color distribution of an image included in the video signal.

(Additional Item 1-17) In the endoscope apparatus according to Additional Item 1-16, the contained substance contains a pigment contained in a living subject.

(Additional Item 1-18) In the endoscope apparatus according to Additional Item 1-17, the dye contains hemoglobin.

(Additional Item 1-19) The endoscope apparatus according to Additional Item 1-18, wherein the hemoglobin includes oxygenated hemoglobin and deoxygenated hemoglobin, and the hemoglobin includes oxygenated hemoglobin and deoxygenated hemoglobin. Obtain oxygen saturation from distribution information.

(Additional Item 1-20) The endoscope apparatus according to Additional Item 1-16, wherein the control means is configured to transmit the illumination light when the calculation is performed by the calculation means. Drive control of the moving means is performed to reduce the width.

(Additional Item 1-21) The endoscope apparatus according to Additional Item 1-1, wherein the first wavelength limiting means and the second wavelength limiting means are provided in the same housing as the light source. Provided.

(Supplementary Item 2-1) The reflected light of the illuminating light irradiating the subject is imaged, and the content contained in the subject is utilized by utilizing the absorption characteristics of the contained material contained in the subject with respect to the wavelength of the illuminating light. An endoscope apparatus capable of measuring a state of a substance, comprising: a light distribution angle adjusting unit provided on an optical path of the illumination light for adjusting a light distribution angle of the illumination light. Endoscope device.

(Additional Item 2-2) In the endoscope apparatus according to Additional Item 2-1, the contained substance includes a pigment contained in a living subject.

(Additional Item 2-3) In the endoscope apparatus according to Additional Item 2-2, the dye contains hemoglobin.

(Additional Item 2-4) The endoscope apparatus according to Additional Item 2-2, wherein the hemoglobin includes oxygenated hemoglobin and deoxygenated hemoglobin, and the hemoglobin includes oxygenated hemoglobin and deoxygenated hemoglobin. Obtain oxygen saturation from distribution information.

(Additional Item 2-5) In the endoscope apparatus according to Additional Item 2-1, the light distribution angle adjusting means includes a liquid crystal lens whose focal length changes by being electrically controlled. It was configured.

(Additional Item 2-6) The endoscope apparatus according to Additional Item 2-1, wherein an image pickup means for picking up an image of the subject, and a video signal is obtained from an image pickup signal obtained by the image pickup means. Image signal processing means for performing image signal processing, and arithmetic means for performing an operation for measuring the state of the contained substance contained in the subject from the color distribution of the image contained in the video signal.

(Supplementary item 3-1) Transmitted light is provided on at least one of the optical paths of the illumination light illuminating the subject or the optical path of the optical image due to the reflected light from the subject irradiated with the illumination light. An endoscope apparatus comprising: a wavelength limiter having a variable wavelength band; and a wavelength controller for controlling a transmission wavelength band by the wavelength limiter.

(Additional Item 3-2) In the endoscope apparatus according to Additional Item 3-1, the wavelength limiting means includes a wavelength variable filter.

(Additional Item 3-3) The endoscope apparatus according to Additional Item 3-1, wherein the wavelength control means is configured to selectively transmit light in a plurality of wavelength bands sequentially. Control.

(Additional Item 3-4) In the endoscope apparatus according to Additional Item 3-1, the wavelength control means may include a plurality of wavelength band groups including a plurality of wavelength bands as one set of wavelength band groups. The wavelength tunable filter is controlled so as to selectively and sequentially transmit light of a plurality of wavelength bands included in a set of wavelength band groups selected from the above.

[0096]

As described above, according to the first aspect of the present invention,
According to the method, it is possible to obtain an observation image using light having a narrow bandwidth and obtain biological function information such as oxygen saturation with high accuracy, and to obtain an observation image that is sufficiently bright and has little noise when the distance to the subject is long. The effect is obtained. According to the second aspect, by reducing multiple reflections when the illumination light is applied to the subject, it is possible to obtain an effect that errors in obtaining biological function information such as oxygen saturation can be reduced. Further, according to the third aspect, it is possible to obtain an effect that it is possible to reduce the size and to improve the expandability when the additional change of the light transmission wavelength band is performed.

[Brief description of the drawings]

FIG. 1 to FIG. 8 relate to a first embodiment of the present invention, and FIG. 1 is an explanatory view showing an entire configuration of an endoscope apparatus.

FIG. 2 is an explanatory diagram showing a configuration of a rotary filter plate.

FIG. 3 is an explanatory diagram showing a spectral transmission characteristic of a filter having a full width at half maximum of 10 nm.

FIG. 4 is an explanatory diagram showing a spectral transmission characteristic of a filter having a full width at half maximum of 30 nm.

FIG. 5 is an explanatory diagram showing light absorption characteristics of deoxygenated hemoglobin and oxygenated hemoglobin.

FIG. 6 is an explanatory diagram showing a position of a filter with respect to a light beam when a subject is located nearby;

FIG. 7 is an explanatory diagram showing a position of a filter with respect to a light beam when a subject is located far away;

FIG. 8 is an explanatory diagram showing a position of a filter with respect to a light beam when a subject is located at an intermediate distance.

FIG. 9 to FIG. 15 relate to a second embodiment of the present invention, and FIG. 9 is an explanatory view showing an entire configuration of an endoscope apparatus.

FIG. 10 is an explanatory diagram showing a configuration of an infrared / visible switching filter.

FIG. 11 is an explanatory diagram showing spectral transmission characteristics of a visible light transmission filter and an infrared light transmission filter.

FIG. 12 is an explanatory diagram showing a configuration of a rotary filter plate.

FIG. 13 is an explanatory diagram showing spectral transmission characteristics of an R filter, a G filter, and a B filter.

FIG. 14 is an explanatory diagram showing a state in which multiple reflection light is applied to a region of interest.

FIG. 15 is an explanatory diagram showing illumination light whose light distribution angle is adjusted.

FIG. 16 and FIG. 17 are related to a third embodiment of the present invention, and FIG. 16 is an explanatory diagram showing an entire configuration of an endoscope apparatus.

FIG. 17 is a timing chart showing the operation of the tunable filter and the CCD.

[Explanation of symbols]

 Reference Signs List 14 ... Rotating filter plate 16 ... Motor 39 ... Dimming circuit 40 ... Filter position control circuit 42a ... Filter group (having a full width at half maximum of 10nm) 42b ... Filter group (having a full width at half maximum of 30nm) 71 ... Liquid crystal lens 81 ... Liquid crystal lens driving circuit 111 … Wavelength tunable filter 112… wavelength control circuit

Continued on the front page F term (reference) 2H040 BA09 BA10 BA13 CA04 CA10 CA12 GA02 GA05 4C061 AA01 AA07 BB02 CC06 DD00 HH54 LL02 MM03 MM07 NN01 NN05 QQ09 RR02 RR04 RR06 RR14 RR18 RR20 RR22 RR30 SS11 A02 Y03 EA08 FA01

Claims (3)

[Claims] 1. A first wavelength limiting means provided on an optical path of illumination light emitted from a light source for illuminating a subject and passing light in a first wavelength band; and provided on an optical path of the illumination light. A second wavelength limiter for passing light in a second wavelength band having a center wavelength substantially the same as that of the first wavelength band and having a different bandwidth; and irradiating the subject through the first wavelength limiter. An endoscope apparatus comprising: means for changing a ratio between an amount of light to be irradiated and an amount of light passing through the second wavelength limiting means and irradiating the subject. 2. An image of reflected light of illumination light applied to a subject is taken, and a state of the contained substance contained in the subject is measured using an absorption characteristic of the contained substance contained in the subject with respect to a wavelength of the illumination light. An endoscope apparatus comprising: a light distribution angle adjusting unit provided on an optical path of the illumination light to adjust a light distribution angle of the illumination light. 3. A transmission wavelength band which is provided on at least one of an optical path of illumination light for illuminating a subject or an optical path of an optical image formed by reflected light from the subject irradiated with the illumination light and having a variable transmission wavelength band. An endoscope apparatus comprising: a wavelength limiting unit; and a wavelength control unit that controls a transmission wavelength band by the wavelength limiting unit.