JP2761238B2 - Endoscope device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope apparatus suitable for observing changes in dye concentration and spectral characteristics of a dye in a living body.

[Prior art] In recent years, by inserting an elongated insertion portion into a body cavity,
2. Description of the Related Art Endoscopes capable of observing organs in a body cavity and the like and performing various treatments using a treatment tool inserted into a treatment tool channel as necessary are widely used.

Also, various electronic endoscopes using a solid-state imaging device such as a charge imaging device (CCD) as an imaging unit have been proposed.

By the way, Japanese Patent Application Laid-Open No. 61-2576
As disclosed in JP-A-92-92 and JP-A-63-311937, there are hemoglobin amount (Hb) in blood and oxygen saturation (SO ₂ ) of hemoglobin.

[Problems to be Solved by the Invention] In the conventional example, an image indicating the distribution of the blood flow rate corresponding to the hemoglobin amount and an image indicating the distribution of the oxygen saturation of hemoglobin are separately displayed. Is an image that is completely different from the image that the physician has diagnosed based on the form and color tone of the diseased part, making it difficult to deal with the original image and requiring a lot of time for diagnosis. There is. Also, it has been difficult to associate a plurality of pieces of information such as the hemoglobin amount and the hemoglobin oxygen saturation.

The present invention has been made in view of the above circumstances, and provides an endoscope apparatus capable of simultaneously observing a plurality of pieces of information related to spectral characteristics in a subject, thereby further improving overall diagnostic performance. It is intended to provide.

[Means for Solving the Problems] An endoscope apparatus according to the present invention includes: an imaging unit configured to capture an image of a subject in a plurality of specific wavelength bands capable of acquiring a plurality of pieces of functional information of the subject; A first function information signal corresponding to the first function information and a second function information signal corresponding to the second function information of the subject based on the imaging signal of the wavelength band of Arithmetic means for outputting the obtained first function information signal as a signal representing a first variable on a color difference plane and outputting the second function information signal as a signal representing a second variable on a color difference plane. And imaging by the imaging means based on the first function information signal output as a signal representing the first variable and the second function information signal output as a signal representing the second variable Display means for displaying a pseudo-color image of the subject.

[Operation] In the present invention, a plurality of pieces of information relating to the spectral characteristics of the subject are obtained from the image information of the subject, and the plurality of pieces of information are a plurality of images which can be visually separated from each other and simultaneously displayed. And a plurality of image signals are displayed.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 to 10 relate to a first embodiment of the present invention, FIG. 1 is a block diagram showing a signal processing circuit which is a main part of the embodiment, and FIG. 2 is an assignment of biological information to image signals. FIG. 3 is a block diagram showing a schematic configuration of the endoscope apparatus, FIG. 4 is an explanatory view showing a band-pass filter turret, FIG. 5 is a side view showing the entire endoscope apparatus, 6 and 7 are explanatory diagrams showing changes in the absorbance of blood due to changes in oxygen saturation of hemoglobin, FIG. 8 is an explanatory diagram showing each filter transmission wavelength region of the rotary filter, FIGS. 9 and
FIG. 10 is an explanatory diagram showing a transmission wavelength region of each filter of the bandpass filter turret.

The endoscope apparatus according to the present embodiment includes an electronic endoscope 1 as shown in FIG. The electronic endoscope 1 has a slender, for example, flexible insertion section 2, and a large-diameter operation section 3 is connected to the rear end of the insertion section 2. A flexible cable 4 extends laterally from a rear end of the operation unit 3, and a connector 5 is provided at a distal end of the cable 4. The electronic endoscope 1 is connected via the connector 5 to a video processor 6 having a light source device and a signal processing circuit built therein. Further, a monitor 7 is connected to the video processor 6.

On the distal end side of the insertion portion 2, a rigid distal end portion 9 and a bending portion 10 which can be bent rearward adjacent to the distal end portion 9 are sequentially provided. By rotating a bending operation knob 11 provided on the operation section 3, the bending section 10 is rotated.
Can be bent in the horizontal direction or the vertical direction. The operation section 3 is provided with an insertion port 12 communicating with a treatment instrument channel provided in the insertion section 2.

As shown in FIG. 3, a light guide 14 for transmitting illumination light is inserted into the insertion section 2 of the electronic endoscope 1. The distal end surface of the light guide 14 is arranged at the distal end 9 of the insertion section 2 so that illumination light can be emitted from the distal end 9. The light guide 14 has an incident end inserted into the universal cord 4 and connected to the connector 5. Further, an objective lens system 15 is provided at the distal end portion 9, and a solid-state imaging device 16 is provided at an image forming position of the objective lens system 15. This solid-state imaging device 16
Has sensitivity in a wide wavelength range from the ultraviolet region to the infrared region including the visible region. Signal lines 26 and 27 are connected to the solid-state imaging device 16. These signal lines 26 and 27 are inserted into the insertion section 2 and the universal cord 4 and connected to the connector 5.

On the other hand, the video processor 6 is provided with a lamp 21 that emits light in a wide band from ultraviolet light to infrared light. As the lamp 21, a general xenon lamp, a strobe lamp, or the like can be used. The xenon lamp and the strobe lamp emit a large amount of ultraviolet light and infrared light as well as visible light. This lamp 21 is connected to a power supply 22
Is supplied with power. A rotary filter 50 driven by a motor 23 is provided in front of the lamp 21. In this rotary filter 50, filters for transmitting light in each wavelength region of red (R), green (G), and blue (B) for normal observation are arranged along the circumferential direction. FIG. 8 shows the transmission characteristics of each of the 50 filters. As shown in this figure, in this embodiment, the filter transmitting B is 800 nm in the infrared band.
The wavelength region B 'in the vicinity also has a characteristic of transmitting light.

The rotation of the motor 23 is controlled by a motor driver 25 to be driven.

Further, a band-pass filter turret is provided on the illumination optical path between the rotary filter 50 and the light guide 14 entrance end.
51 are arranged. In the band-pass filter turret 51, as shown in FIG. 4, two types of filters 51a and 51b having different band-pass characteristics are arranged in the circumferential direction. 9 and 10 show the transmission characteristics of the filters 51a and 51b.

That is, as shown in FIG.
The light passes through a narrow band centered at nm, a narrow band centered at 650 nm, and a narrow band centered at 800 nm. Filter 5
1b transmits the visible band from about 400 to 750 nm, as shown in FIG.

The band-pass filter turret 51 is rotated by a motor 52 whose rotation is controlled by a filter switching device 55. The filter switching device 55 is controlled by a control signal from the switching circuit 43. Then, by selecting the observation wavelength by the switching circuit 43, a filter corresponding to the observation wavelength selected by the switching circuit 43 among the filters 51a and 51b of the bandpass filter turret 51 is disposed on the illumination optical path. The motor 52 is rotated so as to be mounted, and the position of the band-pass filter turret 51 in the rotation direction is changed.

The light that has passed through the rotation filter 50 and has been separated in time series into light of each wavelength region of R, G, and B is further transmitted through a selected filter of the bandpass filter turret 51.
The light enters the incident end of the ride guide 14, is guided to the tip 9 via the light guide 14, is emitted from the tip 9, and illuminates the observation site.

The return light from the observation site due to the illumination light is imaged on the solid-state imaging device 16 by the objective lens system 15, and is photoelectrically converted. This solid-state imaging device 16 includes:
A drive pulse from a driver circuit 31 in the video processor 6 is applied via the signal line 126, and reading and transfer are performed by the drive pulse. The video signal read from the solid-state imaging device 16 is input to a preamplifier 32 provided in the video processor 6 or the electronic endoscope 1 via the signal line 27. The video signal amplified by the preamplifier 32 is input to a process circuit 33, subjected to signal processing such as γ correction and white balance, and converted into a digital signal by an A / D converter. The digital video signal is supplied by a select circuit 35 to three memories (1) 36a, memories (2) 36b, and memories (3) corresponding to, for example, each color of red (R), green (G), and blue (B). 36c is selectively stored. The memory (1) 36a, the memory (2) 36b, and the memory (3) 36c
Are simultaneously read out, converted to analog signals by a D / A converter 37, output as R, G, B color signals, input to an encoder 38, and output from the encoder 38 as an NTSC composite signal. It has become.

The R, G, B color signals and the NTSC composite signal are also input to the color monitor 7, and the color monitor 7 displays the observed part in color.

In the video processor 6, a timing generator 42 for generating the timing of the entire system is provided, and the timing generator 42 synchronizes the circuits such as the motor driver 25, the driver circuit 31, and the select circuit 35. ing.

In this embodiment, the switching circuit 43 includes a filter switching device.
By controlling one of the filters 51a and 51b of the band-pass filter turret 51 selectively in the illumination light path, the wavelength of light transmitted through the rotary filter 50 is controlled by the selected filter. Is further restricted.

When the filter 51a is selected, a narrow band centered at 650 nm is transmitted at the timing when the R transmission filter of the rotary filter 50 is interposed in the illumination optical path, and the center is 569 nm at the timing when the G transmission filter is interposed in the illumination optical path. And a narrow band centered at 800 nm is transmitted at the timing when the B transmission filter is interposed in the illumination light path. The three narrow-band lights are applied to the subject at the timings of R and G, respectively, and the subject image by the illumination light is captured by the solid-state imaging device 16. Then, the images in the two wavelength ranges are output as R and G images, respectively.

FIG. 6 shows the oxygen saturation of hemoglobin (SO
Also described as ₂ . ) Shows the change in blood absorbance (scattered reflection spectrum) due to the change in). As shown in this figure, 569 nm is a wavelength at which the change in SO ₂ hardly changes the blood absorbance. FIG. 7 shows the spectral characteristics of oxy (oxidized) hemoglobin and deoxy (reduced) hemoglobin in order to show the change in the absorbance of blood due to the change in SO _2. As shown in FIG. The vicinity is a region where the absorbance of blood hardly changes due to the change of SO ₂ , and a region where the absorbance is smaller than that of 569 nm. The vicinity of 650 nm is a region where the absorbance of blood changes due to the change of SO ₂ . Therefore, 569n
The distribution of the amount of hemoglobin can be observed by the images in the two wavelength regions of m and 800 nm, and the change in SO ₂ can be observed by the images in the two wavelength regions of 650 nm and 800 nm.

When the filter 51b is selected, the transmission wavelength region of the B transmission filter of the rotary filter 50 is limited to only visible light, and the subject is irradiated with normal R, G, B plane-sequential light. An image is captured by the solid-state imaging device 16. Therefore, a normal color image in the visible band can be observed.

In this embodiment, three different wavelength ranges necessary for obtaining information on the amount of hemoglobin and oxygen saturation on the mucosal surface of the living body output from the endoscope apparatus as shown in FIG. The image signal is further input to the signal processing circuit shown in FIG. The signal processing circuit includes clamp circuits 101, 102, and 103 for clamping three types of input image signals. The signals clamped to a constant value by the clamp circuits 101 to 103 are input to γ 'correction circuits 104, 105, and 106, respectively. It has become. The γ ′ correction circuits 104 to 106 convert γ-corrected image data to be displayed on a television screen or the like in the endoscope apparatus so that the video signal level and the brightness of the video have a linear relationship. In the present embodiment, such γ correction is referred to as γ ′ correction.) The outputs of the γ 'correction circuits 104 to 106 are converted from analog image data into digital image data by A / D converters 107, 108, and 109, respectively, and input to the arithmetic processing unit 110. The arithmetic processing unit 110 converts the image data (V) indicating the lightness and darkness due to distance or shadow from the image data of three different wavelength regions.
And image data (Hb) indicating the distribution of hemoglobin and image data (SO ₂ ) indicating the oxygen saturation of hemoglobin. This operation processing unit 110-3
The two output image data are D / A converters 111 and 1 respectively.
The image data is converted into analog image data at 12,113 and input to the matrix circuit 114. The matrix circuit 114, the signal levels of the brightness information V and the hemoglobin distribution information Hb and hemoglobin oxygen saturation information SO _2, when the output on the TV screen, the vector representing the color to luminance information and two orthogonal, in general The distribution is performed so as to be in the plane of RY and BY. The matrix circuit 11
The three outputs 4 are γ-corrected by γ correction circuits 115, 116, and 117 for display on a television screen, and output as R, G, and B signals via buffer circuits 118, 119, and 120, respectively.

 Next, the operation of the present embodiment will be described.

Image signals in three different wavelength ranges are clamped
The signals are clamped by 101 to 103, corrected by γ 'correction circuits 104 to 106, converted to digital image data by A / D converters 107 to 109, and input to the arithmetic processing unit 110.
Then, in the arithmetic processing unit 110, from the image data of the three different wavelength regions, brightness information V, hemoglobin distribution information Hb and hemoglobin oxygen saturation information SO _2, obtained by the processing. That is, hemoglobin distribution information Hb is obtained by the difference between the two images in the wavelength range of 569nm and 800 nm, the hemoglobin oxygen saturation level information SO ₂ obtained by the difference image by the two-wavelength region of 650nm and 800 nm, for example, 569nm And the image in the two wavelength regions of 800 nm, the brightness information V is obtained. The three output image data V, Hb, and SO ₂ of the arithmetic processing unit 110 are converted into analog image data by D / A converters 111 to 113, input to a matrix circuit 114, and output the brightness information V and the hemoglobin distribution information. Hb and each signal level of hemoglobin oxygen saturation information SO _2, vector R-Y indicating the color to luminance information and two orthogonal, B-
Distribute to Y. The output of the matrix circuit 114 is γ-corrected by γ correction circuits 115 to 117 and
The signals are output as R, G, B signals via 118 to 120.

Here, in the matrix circuit 114, as shown in FIG.
Assigning a hemoglobin oxygen saturation level information SO ₂ in the -Y-axis, perspective or shadows, to be visualized as a luminance signal Y, becomes an image which does not give visually uncomfortable feeling, and in this image, the hemoglobin content and the hemoglobin oxygen The hue changes as follows according to the combination of changes in the saturation.

If the level of normal or general hemoglobin amount and hemoglobin oxygen saturation is set to the origin of each of R-Y and B-Y, that is, an achromatic color, the portion of the mucous membrane where the oxygen saturation does not change and the hemoglobin is large is R or Since the color tone changes in the Mg (magenta) direction, it is expressed in red, and a portion with little hemoglobin changes in the G, Cy (cyan) direction, and thus expressed in blue-green.

Further, a portion having a large hemoglobin amount and a large hemoglobin oxygen saturation is orange with high saturation, and a portion having a set hemoglobin amount and a large hemoglobin oxygen saturation is Ye (yellow).

As described above, according to the present embodiment, the distribution of the hemoglobin amount and the change in the oxygen saturation of hemoglobin, which are very important as the information of the living body, can be grasped simultaneously as the change in color and can be distinguished from each other, and at the same time, the brightness can be changed. Is added, so that the morphological diagnosis of the lesion can be performed at the same time. Accordingly, the medical knowledge of the doctor can be applied, and the visual confirmation of the minute color difference caused by the change of the minute amount of hemoglobin and the change of the oxygen saturation of hemoglobin becomes easy. The effect is that the performance is improved.

In this embodiment, three types of video signals may be directly assigned to R, G, and B without performing conversion by the matrix circuit.

11 and 12 relate to a second embodiment of the present invention.
FIG. 12 is a block diagram showing a signal processing circuit as a main part of the present embodiment, and FIG. 12 is an explanatory diagram showing assignment of biological information to image signals.

In the present embodiment, instead of the arithmetic processing unit 110 in the first embodiment, an arithmetic processing circuit 121 for arithmetically processing brightness information V, hemoglobin distribution information and hemoglobin oxygen saturation information from image data of three different wavelength regions. And a coordinate conversion circuit 122 for converting the output of the arithmetic processing circuit 121 into coordinates. Other configurations are the same as those of the first embodiment.

In the present embodiment, the hemoglobin amount calculated in the arithmetic processing circuit 121 is calculated as E, which is the magnitude of a vector on the RY, BY plane shown in FIG. 12, and the hemoglobin oxygen saturation is calculated by Is calculated as a value represented by the angle θ.

The calculated θ and E are coordinate-converted by the coordinate conversion circuit 122 from the polar coordinate system to the RY, BY coordinate system of the rectangular coordinate system. In the coordinate conversion circuit 122, the arithmetic processing circuit 1
The brightness information V calculated in 21 is assigned to the luminance signal Y as in the first embodiment. The coordinate conversion circuit 122-3
As in the first embodiment, the three output image data are converted into analog image data by the D / A converters 111 to 113, respectively, and distributed by the matrix circuit 114 at a distribution ratio suitable for the R, G, and B signals. Thereafter, the γ correction is performed by the γ correction circuits 115 to 117 and output as R, G, B signals via the buffer circuits 118 to 120.

In the present embodiment, the changes in hemoglobin amount and hemoglobin oxygen saturation expressed on the television monitor are expressed as a change in hemoglobin amount and a change in hue as shown in FIG. Is done.

As described above, according to the present embodiment, it is possible to simultaneously observe changes in hemoglobin amount and hemoglobin oxygen saturation,
The two types of video signal data can be visually separated. That is, by assigning the hemoglobin oxygen saturation and the hemoglobin amount to the hue and the saturation, respectively, of the hue, saturation, and lightness of the three attributes of the color, a portion having a large hemoglobin amount, that is, a portion having a large amount of blood, has a red saturation. The higher the hemoglobin content, the lower the red saturation. On the other hand, the change in the hemoglobin oxygen saturation, by the conventional endoscope has been difficult observation, to express According to this embodiment, the change in the calculated SO ₂ in a wide range of hue regions, diagnostic performance There is an effect of improving.

The hue change region is not limited to 360 °, but is limited to a certain range, so that the maximum and minimum hemoglobin oxygen saturations can be easily separated. In addition, the assignment of biological information to each of hue, saturation, and brightness is not limited to the example of the present embodiment.
For example, the brightness may be assigned to the hemoglobin amount.

It should be noted that the present invention is not limited to the above embodiments, and for example,
As biological information, not only the amount of hemoglobin and the oxygen saturation of hemoglobin but also a change in spectral characteristics of a biological body in combination with a dye such as methylene blue or indocyanine green may be displayed.

Further, the wavelength region for obtaining information on hemoglobin amount and hemoglobin oxygen saturation is not limited to that shown in the embodiment, but can be variously selected.

Further, the endoscope observation site may be observed by transmitted illumination. In this case, illumination may be performed from outside the living body, or light may be guided into the living body and only the tissue may be transmitted and illuminated.

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

[Effects of the Invention] As described above, according to the present invention, a plurality of pieces of information related to spectral characteristics of a subject are assigned to a plurality of image signals that can be visually separated from each other and that can be displayed simultaneously. It is possible to simultaneously observe multiple pieces of information on the subject,
This has the effect of improving the overall diagnostic ability.

[Brief description of the drawings]

1 to 10 relate to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a signal processing circuit which is a main part of this embodiment. FIG. 2 is an explanatory diagram showing assignment of biological information to image signals. FIG. 3 is a block diagram showing a schematic configuration of an endoscope apparatus. FIG. 4, FIG. 4 is an explanatory view showing a band-pass filter turret, FIG. 5 is a side view showing the entire endoscope device, and FIGS. FIG. 8 is an explanatory view showing the change, FIG. 8 is an explanatory view showing the transmission wavelength region of each filter of the rotary filter, FIG.
FIG. 10 is an explanatory diagram showing the transmission wavelength region of each filter of the band-pass filter turret. FIGS. 11 and 12 relate to the second embodiment of the present invention, and FIG. FIG. 12 is a block diagram showing a processing circuit, and FIG. 12 is an explanatory diagram showing assignment of biological information to image signals. 1 ... Electronic endoscope, 50 ... Rotating filter 51 ... Bandpass filter turret 110 ... Calculation processing unit 114 ... Matrix circuit

Claims (1)

(57) [Claims] An imaging unit configured to image a subject in a plurality of specific wavelength bands capable of acquiring a plurality of function information of the subject; and an imaging unit for the subject based on imaging signals in a plurality of wavelength bands output from the imaging unit. A first function information signal corresponding to the first function information and a second function information signal corresponding to the second function information are calculated, and the first function information signal obtained as a result of the calculation is converted to a color difference plane. Calculating means for outputting a signal representing the first variable above and outputting the second function information signal as a signal representing the second variable on the color difference plane; and outputting the signal representing the first variable A table for displaying a pseudo color image of the subject imaged by the imaging means based on the first function information signal and the second function information signal output as a signal representing the second variable. The endoscope apparatus comprising: the means.