JPH06285050A - Endoscope system - Google Patents

Abstract

PURPOSE:To provide the endoscope system which can observe effectively an image for showing a variation of a hemoglobin oxygen saturation degree even at the time of usual visible observation. CONSTITUTION:An R filter has a transmission characteristic containing wavelength of 650nm. A surface-sequentially illuminating light allowed to pass through these R, G and B filters is radiated on an object to be photographed, and its reflected light is picked up by a CCD 19. Subsequently, by memories 24r, 24g and 24b, images of RGB are synchronized, and subjected to color display by a monitor 7. The displayed image is an image constituted of an R image containing wavelength of 650nm and usual images of G and B, and therefore, becomes a visible image containing information of an oxygen saturation degree of hemoglobin. Thus, a variation of the oxygen saturation degree of hemoglobin can be discriminated by the same color tone as a usual visible observation image, a lesional part, etc., can be observed easily, and the diagnostic capability is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope apparatus capable of observing an image showing a change in hemoglobin oxygen saturation for early detection of a lesion.

[0002]

2. Description of the Related Art In recent years, by inserting an elongated insertion portion into a body cavity, various kinds of medical treatments can be performed by observing internal organs in the body cavity and using a treatment instrument inserted into a treatment instrument channel as needed. Endoscopes are widely used.

Various electronic endoscopes using a solid-state image pickup device such as a charge coupled device (CCD) as an image pickup means have been proposed.

In addition, recently, with the electronic endoscope,
Endoscopic device that observes changes in lesions and mucous membranes that were difficult to observe with conventional fiberscopes,
Proposed.

By the way, it is known that knowing the distribution of oxygen saturation of hemoglobin in blood is useful for early detection of a lesion. As a method for measuring the oxygen saturation of hemoglobin in blood, the wavelength at which the absorbance does not change due to the change in oxygen saturation, for example, the absorbance at 569 nm and 586 nm, and the wavelength that greatly changes due to the change in oxygen saturation, such as 577 nm, There is a method of measuring the change in oxygen saturation in the mucosa from the difference between

As a method for obtaining the information on the oxygen saturation, the oxygen saturation can be obtained by using a narrow band filter having an upper wavelength, as disclosed in JP-A-63-311937 and JP-A-1-280442. There has been proposed an endoscopic device that obtains the information of.

[0007]

However, since the conventional endoscope apparatus for obtaining the oxygen saturation image uses the narrow band filter, when the oxygen saturation image is displayed, a normal visible image is obtained. The image had a color tone different from that of the observed image. Further, in such an oxygen saturation image, it is necessary to switch to a visible observation image because a subtle change in the color tone of the mucous membrane cannot be obtained.

The present invention has been made in view of the above circumstances, and provides an endoscope apparatus capable of effectively observing an image showing a change in hemoglobin oxygen saturation even during normal visual observation. It is an object.

[0009]

The endoscope apparatus of the present invention comprises:
An endoscope having at least an image forming optical system, and an image pickup means for picking up a subject image formed by the image forming optical system,
Due to the first wavelength separation means for separating the subject image into images of a plurality of wavelength areas to obtain an image in the visible area, and the change in the oxygen saturation of hemoglobin, the amount of light incident on the light receiving portion of the imaging means is reduced. In addition to separating the image of the changing wavelength band, the first wavelength separating means has a second wavelength separating means provided integrally or separately from the first wavelength separating means, and the first wavelength separating means is provided.
At least a part of the wavelength separating means and the second wavelength separating means are used to obtain an image in the visible region including information on the oxygen saturation of hemoglobin.

[0010]

In the configuration of the present invention, since a visible image containing information on the oxygen saturation of hemoglobin is obtained by using at least a part of the first wavelength separation means and the second wavelength separation means, A change in the oxygen saturation of hemoglobin can be discriminated with a color tone similar to that of a normal visible observation image, and it is easy to observe a lesion or the like and diagnostic ability is improved.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 relate to a first embodiment of the present invention, FIG. 1 is a block diagram showing the entire endoscope apparatus, FIG. 2 is a block diagram showing the configuration of the endoscope apparatus, and FIG. 3 is a rotary filter. FIG. 4 is an explanatory diagram showing a transmission wavelength region of each filter, and FIG. 4 is a characteristic diagram showing absorption spectra of oxyhemoglobin and deoxyhemoglobin.

The endoscope apparatus of this embodiment is equipped with an electronic endoscope 1 as shown in FIG. This electronic endoscope 1 is
It has an elongated and flexible insertion portion 2, and a large-diameter operation portion 3 is connected to the rear end of the insertion portion 2. The operation unit 3
A flexible universal cord 4 extends laterally from the rear end side, and a connector 5 is provided at the end of the universal cord 4. The electronic endoscope 1 is connected via the connector 5 to a video processor 6 including a light source device and a signal processing circuit.
Further, a monitor 7 and an image filing device 8 are connected to the video processor 6.

A hard tip portion 9 and a bending portion 10 adjacent to the tip portion 9 and capable of bending to the rear side are sequentially provided on the tip end side of the insertion portion 2. In addition, the operation unit 3
By rotating the bending operation knob 11 provided in the
It can be bent. Further, the operation section 3 is provided with an insertion opening 12 that communicates with a treatment tool channel provided in the insertion section 2.

As shown in FIG. 2, a light distribution lens 13 and an image forming optical system 14 are arranged at the tip portion 9. On the rear end side of the light distribution lens 13, a light guide 15 made of a fiber bundle is continuously provided.
5 is the insertion portion 2, the operation portion 3, the universal cord 4
It is inserted through and is connected to the connector 5. By connecting the connector 5 to the video processor 6, the illumination light emitted from the light source device in the video processor 6 is incident on the incident end of the light guide 15.

The light source device comprises a lamp 16 and a rotary filter 18 which is disposed in the illumination optical path of the lamp 16 and is rotated by a motor 17. The lamp 16 emits light from ultraviolet to infrared. The rotary filter 18 has filters 18a, 18 for transmitting light in different wavelength regions, respectively.
b and 18c are arranged along the circumferential direction. The characteristics of the rotary filters 18a, 18b, 18c correspond to the characteristics of R, G, B shown in FIG. 3, respectively. The light emitted from the lamp 16 is transmitted to the rotary filter 18
Thus, the light is separated into each wavelength region in time series and is incident on the incident end of the light guide 15.
This illumination light is directed to the tip 9 by the light guide 15.
Is emitted from the front end surface thereof, passes through the light distribution lens 13, and is irradiated onto the subject.

On the other hand, at the image forming position of the image forming optical system 14, a solid-state image pickup device, for example, a CCD 19 is arranged. Then, a subject image illuminated by the field sequential illumination light is formed by the image forming optical system 14,
It is converted into an electric signal by the CD 19. This CCD 19
The image signal from is a predetermined range of electrical signals (for example, 0
It is adapted to be input to an amplifier 20 for amplifying to about 1 volt. The electric signal output from the amplifier 20 is γ-corrected by the γ-correction circuit 21, converted into a digital signal by the A / D converter 22, and input to the 1-input / 3-output selector 23. R sent in time series
The GB signal is separated into R, G, and B color signals by the selector 23 and input to the memory unit 24. The separated R, G, B color signals are respectively stored in the memories 24r, 24g, 24 of the memory section 24 corresponding to R, G, B, respectively.
It is designed to be stored in b. Each memory 24r, 2
The image signals read from 4g and 24b are respectively
It is converted into an analog signal by the D / A converters 25r, 25g, 25b, and R, G, B signal output terminals 26, 27, 2
It is designed to be output from 8. In addition, the R,
The sync signal SYNC from the sync signal generating circuit 29 is output from the sync signal output terminal 30 together with the G and B signals. Then, the R, G, B signals and the synchronizing signal are input to the monitor 7, the image filing device 8 and the like.

Further, a control signal generator 31 for controlling the destination (selection) of the image signal and the transfer timing at the time of transferring the image signal is provided. The control signal generator 31
The A / D converter 22, selector 23, R, G, B
Each memory 24r, 24g, 24b, D / A converter 2
Control signals are sent to the 5r, 25g, and 25b, the synchronizing signal generating circuit 29, and the motor 17, respectively.

Next, the operation of this embodiment will be described with reference to FIG.

The ultraviolet to infrared light emitted from the lamp 16 enters a rotary filter 18 rotated by a motor 17. As described above, the rotary filter 18 has the R, G, and B filters having the transmission characteristics shown in FIG.

Regarding the R filter as the first wavelength separating means and the second wavelength separating means, the reflection spectral characteristics due to the change in the oxygen saturation of hemoglobin are compared with the regions of the transmitted light of the G and B filters. It transmits red light including 650 nm where the change is remarkable. Further, since the R filter has a wider transmission wavelength range than the G and B filters, the amount of received light is larger than that of the other filters, and the red color is saturated. Therefore, by making the transmittance of this R filter lower than that of the G and B filters,
It prevents the red color from becoming saturated. The G and B filters form a first wavelength separating means.

The light from the lamp 16 is decomposed into light having wavelengths corresponding to the filters 18a, 18b and 18c in time series, guided into the body cavity through the light guide 15, and distributed to the light distribution lens 13. Is radiated as illumination light into the body cavity via. The subject image formed by each illumination light is formed by the imaging optical system 14
An image is formed on the CCD 19 by the and converted into an electric signal. The output signal of the CCD 19 is amplified by the amplifier 20 and converted into a predetermined γ characteristic by the γ correction circuit 21. The output of the γ correction circuit 21 is converted into a digital signal by the A / D converter 22, passes through the selector 23, is decomposed into wavelengths in time series, and is stored as an image in the memories 24r and 2r.
Stored in 4g, 24b. That is, the selector 23 switches the output in synchronization with the rotation of the rotary filter 18.

The video signals read from the memories 24r, 24g, 24b are synchronized, converted into analog video signals by the D / A converters 25r, 25g, 25b, and output as R, G, B signals. It

Here, the reflection spectral characteristic of hemoglobin changes due to the change in oxygen saturation of hemoglobin. That is, it is possible that the reflectance spectral characteristics (absorbance) of blood changes,
Known from the past. The change in the absorbance of blood due to the change in the oxygen saturation of hemoglobin depends on the difference between the reflection spectral characteristics of oxy (oxidized) hemoglobin and deoxy (reduced) hemoglobin. As shown in FIG.
In the vicinity of nm, the absorbance of blood changes greatly due to the change in oxygen saturation of hemoglobin. Therefore, this 65
By illuminating with light in the wavelength range including near 0 nm,
An image in which changes in oxygen saturation of hemoglobin can be observed,
Will be obtained. That is, in this embodiment, the R
The light that has passed through the filter is light in the wavelength range including the vicinity of 650 nm.

Therefore, 650 nm transmitted through the R filter
The light including the light of the wavelength is radiated into the body cavity, for example, and the image obtained by the reflected light is stored in the R memory 24r. That is, the image stored in the R memory 24r includes image information in which the change in the absorbance of blood is strongly reflected. Since the change in the absorbance of blood depends on the change in the oxygen saturation of hemoglobin as described above, when the oxygen saturation of hemoglobin changes, the image updated in the R memory 24r captures the change. It is an image.

Then, the R memory 24r and the G memory 2
In the 4g, B memory 24b, the synchronized R, G, B images are displayed in color on the monitor 7 and recorded on the image filing device 8.

As described above, according to the present embodiment, it is possible to obtain a change in the oxygen saturation of hemoglobin even during visible observation, so that the oxygen of hemoglobin can be obtained while obtaining a subtle color change during visible observation. The degree of saturation, that is, the lesion where the change in oxygen saturation in blood is remarkable can be clearly discriminated, and the diagnostic ability can be improved.

5 to 7 relate to the second embodiment of the present invention. FIG. 5 is a block diagram showing the configuration of an endoscope apparatus, FIG. 6 is an explanatory view showing a rotary filter, and FIG. 7 is each rotary filter. It is explanatory drawing which shows the transmission wavelength range of a filter.

In this embodiment, a rotary filter 32 as shown in FIG. 6 is provided instead of the rotary filter 18 in the first embodiment. Further, the selector 23
1-input 4-output selector 33 instead of
Instead of 4, the selector 35 is provided at the subsequent stage of the memory 34 and the memories 34a and 34r. Other configurations and operations similar to those of the first embodiment are designated by the same reference numerals and description thereof will be omitted.

Next, the operation of this embodiment will be described with reference to FIG. The rotary filter 32 has a transmission characteristic as shown in FIG. 7 and has a filter 32a as a second wavelength separating means and a filter 3 as a first wavelength separating means.
2b, 32c, and 32d separate the four wavelength regions in time series so that the illumination light can enter the light guide 15.

The filters 32b, 32c and 32d are
The filter 32a is a filter that transmits light in a wavelength region in which visible observation is possible, and the filter 32a has a reflection spectral characteristic significantly changed at 650 nm due to a change in oxygen saturation of hemoglobin.
It is a filter that transmits light in the wavelength region in the vicinity. The subject images illuminated by these filters are stored in the memories 34a, 34r, 34g, 34b, respectively. Then, according to a selection instruction (select signal) from a changeover switch (not shown) provided on a front panel (not shown) or the like, selection is made as to whether observation is performed on an RGB image or an R′GB image. Has become. That is, the selector 35 selects one of the images in the memory 34a or the memory 34r based on the select signal.

The video signals read from the memories 34a, 34g, 34b or 34r, 34g, 34b are synchronized and converted into analog signals by the D / A converter 25, and R ', G, B signal, or R,
It is output as G and B signals.

According to the present embodiment, the R'GB image
While an image containing information on the oxygen saturation of hemoglobin can be obtained, a conventional RGB image can be observed by switching the observation image by switching the changeover switch or the like.

In this embodiment, the transmission filter near 650 nm has a narrower band than that of the filter of the first embodiment, so that an image more sensitive to changes in oxygen saturation can be obtained. Other configurations and effects
The description is omitted because it is the same as the first embodiment.

8 to 12 relate to the third embodiment of the present invention, and FIG. 8 is a block diagram showing the construction of an endoscope apparatus, FIG.
Is an explanatory view showing the configuration of the filter turret, FIG. 10 is an explanatory view showing the transmission wavelength region of each filter of the rotary filter,
11 is an explanatory diagram showing a transmission wavelength region of the first wavelength band limiting filter, and FIG. 12 is an explanatory diagram showing a transmission wavelength region of the second wavelength band limiting filter.

In this embodiment, instead of the rotary filter 18 in the first embodiment, a first wavelength separating means having filters 36a, 36b and 36c having a transmission wavelength region as shown in FIG. 10 is constructed. Rotating filter 36
Is provided. Further, a filter turret 37 having a structure as shown in FIG. 9 is inserted in the optical path on the lamp side of the rotary filter 36.

The filter turret 37 is a first wavelength band limiting filter 39 which constitutes a first wavelength separating means.
And a second wavelength band limiting filter 40 as a second wavelength separating means. The second wavelength band limiting filter 40 is composed of two filters 40a and 40b and has a transmission wavelength region as shown in FIG.

The filter turret 37 is a motor 38.
Rotation of the first wavelength band limiting filter 39 or the second wavelength band limiting filter 40 on the optical path,
It is supposed to be inserted.

Although the second wavelength band limiting filter is composed of two filters in this embodiment, one filter having a transmission wavelength region as shown in FIG. 12 may be used. Other configurations and operations similar to those of the first embodiment are designated by the same reference numerals and description thereof will be omitted.

Next, the operation of this embodiment will be described with reference to FIGS. The rotary filter 36
Is a filter 3 having a transmission characteristic as shown in FIG.
It has 6a, 36b and 36c. However, the filter turret 3 is provided between the rotary filter 36 and the lamp 16.
7 is inserted. Therefore, the filter turret 3
7, a first wavelength band limiting filter 39,
The second wavelength band limiting filter 40 allows two types of illumination light to be emitted.

As shown in FIG. 11, the first wavelength band limiting filter 39 has a characteristic of transmitting light in the wavelength region of about 400 nm to about 650 nm. On the other hand, as shown in FIG. 12, the second wavelength band limiting filter 40 has the wavelengths of about 400 nm to about 570 nm and about 610 nm to about 7 nm.
It has a characteristic of transmitting light in the wavelength region up to 00 nm, respectively.

When the first wavelength band limiting filter 39 is disposed on the optical path, R, shown in FIG. 7 of the second embodiment,
Light in the wavelength regions of G and B is emitted in time series. Further, when the second wavelength band limiting filter 40 having the transmission wavelength region as shown in FIG. 12 is inserted in the optical path, R ′, G, B shown in FIG. 7 of the second embodiment.
The light in the wavelength region of is irradiated in time series.

If the rotation of the motor 38 is controlled by an instruction given from a front panel (not shown) or the like, the wavelength band limiting filter can be switched. Therefore,
In this embodiment, it is possible to switch between the RGB image and the R′GB image for observation. The other actions and effects are the same as those of the first and second embodiments, and the description thereof will be omitted.

13 to 15 relate to the fourth embodiment of the present invention. FIG. 13 is an explanatory view showing the structure and operation of the rotary filter, and FIG. 14 is a diagram showing R and R provided in the rotary filter.
FIG. 15 is an explanatory diagram showing the configuration of the R'filter, and FIG. 15 is a block diagram showing the configuration of the endoscope apparatus.

In this embodiment, instead of the rotary filter 18 in the first embodiment, a rotary filter 41 having the structure shown in FIG. 13 is provided.

The rotary filter 41 is a filter 4 having a transmission wavelength region as shown in FIG. 7 of the second embodiment.
1a, 41b, 41c, 41d are provided. First
The filter 41a which constitutes the wavelength separating means of
The filter 41b as the wavelength separating means of FIG.
4, it is configured as a fan-shaped filter 41A. Further, the first wavelength separation means also includes the filters 41c and 41d.

FIG. 13 (a) shows the rotary filter 41 when the fan-shaped R, R'filter 41A is removed. In this state, the filter 41 is provided with G and B filters 41c and 41d and an unfiltered portion 41e. Stoppers 42, 42 are provided on both sides of the unfiltered portion 41e on the circumference, and are separated by half the length of the circumference of the R, R'filter.

As shown in FIGS. 13 (b) and 13 (c), the R, R'filter 41A has a structure that can slide with respect to the rotary filter 41. That is, depending on the rotation direction of the rotary filter 41, the portion 41 without the filter is
e to R filter 41a or R'filter 41b
However, the structure is such that they face each other. Other configurations and operations similar to those of the first embodiment are designated by the same reference numerals and description thereof will be omitted.

Next, the operation of this embodiment will be described with reference to FIG. The rotary filter 41 is a rotary filter having the above-mentioned configuration, and is the same as that of the second embodiment shown in FIG.
It is possible to illuminate the illumination light in the wavelength region, R, G, B and R ', G, B as shown in FIG.

For example, from the front panel and the like, R,
When an instruction to select to illuminate the G and B wavelength regions is output, the rotary filter 41 rotates counterclockwise as shown in FIG. 13B, so that the fan-shaped R, R'filter 41 is rotated.
A tilts to the right, which means that the R filter 41a is selected. Therefore, the R, G, and B illumination lights are sequentially illuminated. Similarly, if it is selected to illuminate light in the R ', G, and B wavelength regions, the rotary filter 4
1 rotates to the right as shown in FIG. 13 (c),
The fan-shaped R, R 'filter 41A is tilted to the left, and the R'filter 41b is selected. Therefore, R ',
The illumination lights of G and B are sequentially illuminated. By the above, an RGB image and an R'GB image are obtained.

The other operations and effects are the same as those in the first and second embodiments, and the description thereof will be omitted.

16 to 18 relate to the fifth embodiment of the present invention, FIG. 16 is an explanatory view showing the configuration of the rotary filter, FIG. 17 is a timing chart for explaining the operation of the present embodiment, and FIG. It is a block diagram showing composition of an endoscope apparatus.

In this embodiment, instead of the rotary filter 18 in the first embodiment, a rotary filter 43 having the structure shown in FIG. 16 is provided. The rotary filter 43 is provided with filters 43a, 43b, 43c having wavelength transmission characteristics as shown in FIG. 7 of the second embodiment. The R and R'filters 43a forming the second wavelength separating means and the first wavelength separating means are the G and B filters 43b and 43c forming the first wavelength separating means.
It is formed in a size of 1/2. Further, as shown in FIG. 18, a read control circuit 44 is connected to the CCD 19. Other than that, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

Next, the operation of this embodiment will be described with reference to the timing chart of FIG.

The illumination light emitted from the light guide 15 is applied to the subject at the timing shown in FIG. 17 (a). The CCD 19 receives the reflected light from the subject and converts it into an electric signal. The electric signal of the CCD 19 is read under the control of the read control circuit 44.

The read control circuit 44 switches the timing in accordance with a read selection instruction from the front panel or the like, and switches the CC at the selected predetermined timing.
Read D19. The read output signal of the CCD 19 is sent to the signal processing circuit after the amplifier 20 and subjected to the same processing as described above.

The predetermined read timing in the read control circuit 44 is shown in FIG. RGB
When obtaining an image, the predetermined timing is as shown in FIG.
As shown in (b), the electrical signals captured at the timing of the R, G, and B illumination light are read out. On the other hand, in the case of obtaining R ', G, B images, the predetermined timing is such that the electrical signals picked up at the timing of the illumination light of R', G, B are read out as shown in FIG. 17 (c). It has become.

The other operations and effects are the same as those of the first and second embodiments, and the description thereof will be omitted.

19 to 20 relate to a sixth embodiment of the present invention, and FIG. 19 is a block diagram showing the configuration of an endoscope apparatus,
FIG. 20 is an explanatory diagram showing the transmission wavelength region of each filter of the rotary filter.

In this embodiment, instead of the rotary filter 18 of the first embodiment, the rotary filter 43 of the fifth embodiment is used.
Is provided. The transmission wavelength characteristic of each filter of the rotary filter 43 is as shown in FIG. Other,
The same configurations and operations as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

Next, the operation of this embodiment will be described. The rotary filter 43 is a rotary filter having the same configuration as that of the fifth embodiment, and the transmission wavelength region of each filter is as shown in FIG. Therefore, the wavelength range of the illumination light radiated in time series by the rotary filter 43 is the same as in FIG. 3 of the first embodiment. The R memory 24r is adapted to store an image obtained by the illumination light transmitted through the R, R'filter 24a. Therefore, the operation and effect are similar to those of the first embodiment, and the description thereof will be omitted.

FIG. 21 is an explanatory view showing the structure of the rotary filter according to the seventh embodiment of the present invention.

In the seventh embodiment, a rotary filter 44 having the structure shown in FIG. 21 is provided instead of the rotary filter 18 in the first embodiment. That is, the rotary filter 44 includes an R'R filter, a B filter,
A G filter is arranged. The transmission wavelength characteristics of each filter of the rotary filter 44 are the same as those of the first embodiment, but the transmittances of R′R, G and B are the same. Other than that, the same configurations and operations as those of the first embodiment are the same, and the drawings and description are omitted, and only different points will be described.

The rotary filter 44 has a structure as shown in FIG. 21, and the aperture ratio of the R'R filter is G, B.
Compared to the filter, it is less. Therefore, the illumination light illuminated in time series by the rotary filter 44 becomes illumination light having the same transmission wavelength characteristic as that of FIG. 3 of the first embodiment. Therefore, the other actions and effects are the same as those in the first embodiment, and the description thereof will be omitted.

22 to 23 relate to the eighth embodiment of the present invention, and FIG. 22 is a block diagram showing the configuration of the endoscope apparatus,
FIG. 23 is a block diagram showing the configuration of the image processing unit.

In the endoscope apparatus of the eighth embodiment, an image processing unit 45 is interposed and connected to the latter stage of the D / A converter 25 in the endoscope apparatus of the first embodiment. Other than that, the configuration and operation of the endoscope apparatus are the same as those in the first embodiment, and the description thereof is omitted.

FIG. 23 is a block diagram showing the structure of the image processing unit 45. The R, G, B signals input by the A / D converter 46 are converted into digital signals and output to the inverse γ correction circuit 47. The inverse γ correction circuit 47 cancels the γ correction for the input signal because the predetermined γ correction is performed by the γ correction circuit 21. The output of the inverse γ correction circuit 47 is the frame memory 48 and the divider 49.
Are input respectively.

The divider 49 calculates R / G or R / B from the input RGB signal and outputs it to the ROM 50. The ROM 50 performs emphasis processing on the input R / G (or R / B) signal according to a coefficient that can be adjusted from the outside. The output of the ROM 50 is a ROM
The emphasis conversion is performed on the original images input to 51a, 51b and 51c and adjusted in timing by the frame memory 48. The converted emphasized image is output to the γ correction circuit 52, and a predetermined γ correction conversion is performed. The output of the γ correction circuit 52 is input to the D / A converter 53, converted into an analog signal, and then output from the RGB signal output terminals 26, 27, 28.

Next, the operation of this embodiment will be described.
The image corresponding to each wavelength band captured by the CCD 19 is input to the image processing unit 45, and the divider 49 calculates the ratio of R and G or R and B signals. This calculation result is emphasized in the ROM 50, and the ROM 51a, 5
By reflecting on the original image via 1b and 51c,
It is possible to obtain an image with emphasis on oxygen saturation.

According to this embodiment, an oxygen saturation enhanced image can be obtained with respect to the image obtained in the first embodiment.
Oxygen supply conditions such as lesions can be easily identified, leading to improved diagnostic ability.

In this embodiment, the digital signal is converted into an analog signal in the endoscope apparatus and output to the image processing unit 45, but the digital signal may be output as it is.

24 to 27 relate to the ninth embodiment of the present invention, FIG. 24 is an explanatory view showing the transmission wavelength characteristic of each filter of the rotary filter, and FIG. 25 is a view of the band limiting filter provided in the filter turret. 26 is an explanatory view showing a transmission wavelength characteristic, FIG. 26 is a wavelength characteristic diagram of illumination light when the band limiting filter 54 is inserted on the optical path, and FIG. 27 is a wavelength characteristic diagram of illumination light when the band limiting filter 55 is inserted on the optical path. It is a wavelength characteristic diagram.

In this embodiment, the transmission wavelength characteristics of the filters 36a, 36b, 36c of the rotary filter 36 in the third embodiment are the transmission characteristics shown in FIG. That is, as shown in FIG. 24, the R filter of the present example includes a wavelength of 650 nm and limits the upper limit of the transmission wavelength. Also, in contrast to the B filter of the third embodiment, the filter of this embodiment has the transmission wavelength bands B and B ′ shown in FIG. Further, in contrast to the G filter of the third embodiment, the filter of this embodiment has the transmission wavelength range of G and G'shown in FIG.

Further, in this embodiment, in the filter turret 37, instead of the filters 39 and 40, the band limiting filter 5 having the characteristics shown in FIG.
4, 55 are arranged. The other structure is the same as that of the third embodiment, and the drawings and the description regarding the structure of the apparatus are omitted.

Next, the operation of this embodiment will be described.
The band-limiting filter 54 is inserted in the optical path, and the rotary filter rotates in the optical path, so that the illumination light having the transmission wavelength characteristic as shown in FIG. 26 is applied to the subject. Further, by retracting the band limiting filter 54 from the optical path and inserting the band limiting filter 55 in the optical path, the illumination light having the transmission wavelength characteristic as shown in FIG. 27 is applied to the subject. That is, the band limiting filter 54, as shown in FIG.
It has a transmission characteristic including a wavelength range of. Further, as shown in FIG. 27, the band limiting filter 55 includes a part of R, that is, a wavelength of 650 nm and a long wavelength side of R, and B ′.
And G ′ have a transmission characteristic including a wavelength range. Therefore, the filter 55 has a narrower bandwidth than the case where the filter 54 is inserted, and an image more sensitive to changes in oxygen saturation can be obtained.

According to this embodiment, the band limiting filter 54
Is inserted in the optical path, a normal visible observation image is obtained, while when the band limiting filter 55 is inserted in the optical path, an image in which the change in the oxygen saturation of hemoglobin can be determined is obtained.

Furthermore, the present embodiment can be applied not only to images in which changes in oxygen saturation can be obtained, but also to observation of hemoglobin amount and infrared images and ICG density images. The rest of the configuration, functions and effects are the same as in the third embodiment, and the explanations are omitted.

Incidentally, a signal processing circuit similar to, for example, the signal processing circuit shown in FIG. 23 may be interposed and connected to the subsequent stage of the endoscope apparatus of this embodiment to perform the emphasis processing.

28 to 33 relate to the tenth embodiment of the present invention, FIG. 28 is an explanatory view showing the constitution of an endoscope apparatus, FIG. 29 is an explanatory view showing the constitution of a rotary filter, and FIG. 30 is a rotary filter. 31 is a characteristic diagram showing the transmission characteristic of each transmission filter, FIG. 31 is an explanatory diagram showing the configuration of the signal processing circuit, FIG. 32 is an explanatory diagram showing the configuration of the color separation filter array, and FIG. 33 is each transmission filter of the color separation filter array. It is explanatory drawing which shows the transmission wavelength characteristic of.

As shown in FIG. 28, a color separation filter array 56 constituting first and second wavelength separation means is arranged on the front surface of the CCD 19.

On the other hand, in the video processor 6, there is provided a lamp 57 which emits light in a wide band from ultraviolet light to infrared light. As the lamp 57, a general xenon lamp, a strobe lamp or the like can be used. The xenon lamp and strobe lamp emit a large amount of not only visible light but also ultraviolet light and infrared light. Electric power is supplied to the lamp 57 from a power supply unit 58. In front of the lamp 57, a rotary filter 60 constituting first and second wavelength separating means, which is rotationally driven by a motor 59, is arranged. In this rotary filter 60, filters 60a and 60b having the transmission wavelength region shown in FIG. 30 are arranged along the circumferential direction as shown in FIG. The rotary filter 60 can be inserted and removed from the optical path.

The rotation of the motor 59 is controlled by a motor driver 61 so that the motor 59 is driven.

Light transmitted through the rotary filter 60 and separated in time series into light in each wavelength region shown in FIG. 30, or white light illuminated by the rotary filter 60 retracting from the optical path, The light is incident on the incident end of the light guide 15, guided to the tip 9 through the light guide 15, emitted from the tip 9, and illuminates the observation site.

An optical image of the subject illuminated by this illumination light is formed on the image pickup surface of the CCD 19 by the objective lens system 14. At that time, color separation is performed by the color separation filter array 56. This color separation filter array 56, as shown in FIG. 32, includes G (green), Cy (cyan), and Ye.
The color transmission filters of three colors (yellow) are arranged in a mosaic pattern. The transmission characteristics of the G, Cy, and Ye filters are shown in FIG.

The CCD 19 is read by applying a drive signal from the driver 61 in the video processor 6, amplified by the amplifier 62 in the video processor 6, and then passed through the LPFs 63, 64 and the BPF 65.

The LPFs 63 and 64 are, for example, 3 MHz,
It shows a cutoff characteristic of 0.8 MHz, and a signal passing through each of them is divided into a high-frequency luminance signal YH and a low-frequency luminance signal YL, and the process circuits 66 and 67 respectively.
Is input to and the γ correction and the like are performed. The high frequency side luminance signal YH passed through the process circuit 66 is supplied to the horizontal correction circuit 6
After the horizontal contour correction and the horizontal aperture correction are performed in step 8, the color encoder 69 inputs the color contour.

Further, the luminance signal YL on the low frequency side which has passed through the process circuit 67 is supplied to the matrix circuit 70 for image display.
Is input to, and tracking correction is performed.

On the other hand, the read signal of the CCD 19 is
A color signal component is extracted by passing it through a BPF 65 having a pass band of 3.58 ± 0.5 MHz, and this color signal component is 1
It is input to the HDL (1H delay line) 71, the adder 72 and the subtractor 73, and the color signal components B and R are separated and extracted. In this case, the output of the 1HDL 71 is processed by the process circuit 61, and further, vertical aperture correction is performed by the vertical correction circuit 74.
And the mixed output is input to the adder 72 and the subtractor 73. Then, the color signal B of the adder 72
And the color signal R of the subtractor 73 respectively correspond to the γ correction circuit 7
6 and 77, and γ correction is performed using the luminance signal YL on the low frequency side that has passed through the correction circuit 78. Further, the γ-corrected color signals B and R are input to the demodulators 79 and 80, respectively, converted into demodulated color signals B and R, and then input to the matrix circuit 70.

Color difference signals RY and BY are generated by the matrix circuit 70, and then input to the color encoder 69 to obtain a luminance signal in which the luminance signals YL and YH are mixed and a color difference signal RY, A chroma signal obtained by quadrature-modulating BY with subcarriers is mixed, and a synchronization signal is further superimposed, and a composite video signal is output from the NTSC output end. In addition, from the front stage of the matrix circuit 70, the RG
The B signal is connected to the signal processing circuit 81.

A synchronizing signal is input to the driver 82 by the synchronizing signal generating circuit 83, and the driver 82
Drives the drive signal synchronized with the synchronization signal to the CCD 19
Output to.

Further, the composite video signal is displayed in color on the observation site by the color monitor 7.

The configuration of the signal processing circuit 81 is as shown in FIG. That is, the R signal of the RGB image input to the signal processing circuit 81 is stored in the frame memories 84a and 84b by the selector 85 that operates in synchronization with the rotation of the rotary filter 60.

The R signal includes an R image illuminated by the filter 60a and an R image illuminated by the filter 60b. Therefore, R illuminated by the filter 60a
The image is stored in the frame memory 84a, while the R ″ image illuminated by the filter 60b is stored in the frame memory 84a.
stored in b.

The R, R "signals input to the frame memories 84a, 84b are output by the difference circuit 86 after subtracting the R image by the filter 60a from the R" image by the broadband filter 60b. The difference output R'is output simultaneously with the G and B images stored in the frame memories 84c and 84d, respectively.

Next, the operation of this embodiment will be described.
During normal visible observation, the rotary filter 60 is retracted from the optical path, and white light is illuminated on the subject.

On the other hand, when observing the change in oxygen saturation of the mucosal tissue, the rotary filter 60 is inserted in the optical path, and the illumination light from the filter 60a and the illumination light from the filter 60b are illuminated in time series. The images obtained by time-sequential illumination are separated into R, G, B images and input to the signal processing circuit 81. The signal input to the signal processing circuit 81 is 650 by subtracting the image illuminated by the filter 60a from the image illuminated by the filter 60b.
An R ′ image similar to that obtained by illuminating light in the wavelength range of nm to 780 nm is obtained. The R ′ image obtained by the illumination light in the wavelength region and the G and B images stored in the frame memories 84c and 84d are synchronized and output, whereby the oxygen saturation of hemoglobin changes significantly. The resulting image will be obtained.

34 to 35 relate to the eleventh embodiment of the present invention. FIG. 34 is a characteristic diagram showing a transmission wavelength characteristic of each filter of a rotary filter, and FIG. 35 is an explanatory diagram showing a configuration of a signal processing circuit. .

In this embodiment, in the endoscope apparatus of the tenth embodiment, a rotary filter 87 having the characteristics shown in FIG. 33 is arranged instead of the rotary filter 60.
This rotary filter 87 is the filter 60 shown in FIG.
Filters 87a, 87 provided in place of a, 60b
b, and the transmission wavelength characteristic thereof is as shown in FIG. That is, the filter 87a that constitutes the first wavelength separation means has a transmission characteristic in the wavelength range up to 650 nm. Further, the filter 87b forming the second wavelength separation means has a transmission characteristic of a narrow bandwidth around 650 nm and before and after the wavelength.

In this embodiment, instead of the signal processing circuit 81 of the tenth embodiment, the signal processing circuit 89 shown in FIG.
Is equipped with. The configuration of the signal processing circuit 89 is shown in FIG.
As shown in, a selector 88 is provided instead of the difference circuit 86 in the tenth embodiment. Other than this, in the present embodiment, the configuration shown in FIG. 28 is the same as that of the tenth embodiment, and therefore will be omitted. At the same time, the same configurations and operations as those of the tenth embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different points will be described.

Next, the operation of this embodiment will be described.
During normal visible observation, the rotary filter 87 is retracted from the optical path, and white light is illuminated on the subject.

On the other hand, when observing the change in oxygen saturation of the mucosal tissue, the rotary filter 87 is inserted in the optical path, and the illumination light from the filter 87a and the illumination light from the filter 87b are illuminated in time series. The images obtained by time-sequential illumination are separated into R, G, B images and input to the signal processing circuit 89. The signal input to the signal processing circuit 89 switches between the R image illuminated by the filter 87a and the narrow band image illuminated by the filter 87b.
This selected one of the images and the G and B images stored in the frame memories 84c and 84d are synchronized and output to obtain an image in which the change in the oxygen saturation level of hemoglobin is prominent. Will be done. Other actions and effects are similar to those of the tenth embodiment.

The present invention is not limited to the contents of the above-mentioned embodiment, but changes in the oxygen saturation of hemoglobin
Any wavelength may be used as long as it has a large change in reflection spectral characteristics, for example, 900 nm on the long wavelength side from the absorption point such as 805 nm.
It may be in the vicinity.

If a device such as an image processing unit for performing conventional image processing such as color enhancement is connected to the subsequent stage of the video processor of the present invention and color enhancement is performed, the change in oxygen saturation is further enhanced. It is possible to obtain a clear image. Alternatively, the image processing unit may be provided in the video processor instead of being independent as the image processing unit.

Furthermore, the present invention is not limited to an electronic endoscope having a solid-state image pickup device at the distal end of the endoscope insertion portion, but can also be applied to an eyepiece portion of an endoscope such as a fiberscope or a rigid endoscope capable of macroscopic observation. Alternatively, it can be applied to an endoscope which is used by connecting to an external television camera having a solid-state image pickup device such as a CCD by replacing the eyepiece unit.

[0104]

As described above, according to the present invention,
A visible observation image similar to the conventional one can be obtained, and the change in the oxygen saturation of hemoglobin can be discriminated, and an image with a color tone almost similar to that of the visible observation image can be obtained. In addition, it becomes possible to obtain functional information of the living body at the same time from the change in the oxygen saturation of hemoglobin, and it is easy to observe the lesioned part, etc., and it is possible to improve the diagnostic ability.

[Brief description of drawings]

FIG. 1 to FIG. 4 relate to a first embodiment, and FIG. 1 is a configuration diagram showing an entire endoscope apparatus.

FIG. 2 is a block diagram showing a configuration of an endoscope device.

FIG. 3 is an explanatory diagram showing a transmission wavelength region of each filter of the rotary filter.

FIG. 4 is a characteristic diagram showing absorption spectra of oxyhemoglobin and deoxyhemoglobin.

5 to 7 relate to the second embodiment, and FIG. 5 is a block diagram showing a configuration of an endoscope apparatus.

FIG. 6 is an explanatory view showing a rotary filter.

FIG. 7 is an explanatory diagram showing a transmission wavelength region of each filter of the rotary filter.

8 to 12 are related to a third embodiment, and FIG. 8 is a block diagram showing a configuration of an endoscope apparatus.

FIG. 9 is an explanatory diagram showing a configuration of a filter turret.

FIG. 10 is an explanatory diagram showing a transmission wavelength region of each filter of the rotary filter.

FIG. 11 is an explanatory diagram showing a transmission wavelength region of a first wavelength band limiting filter.

FIG. 12 is an explanatory diagram showing a transmission wavelength region of a second wavelength band limiting filter.

FIGS. 13 to 15 relate to the fourth embodiment, and FIG. 13 is an explanatory diagram showing the configuration and operation of the rotary filter.

FIG. 14 is a schematic diagram of R provided in the rotary filter;
Explanatory drawing which shows the structure of an R'filter.

FIG. 15 is a block diagram showing a configuration of an endoscope device.

FIG. 16 to FIG. 18 relate to the fifth embodiment, and FIG. 16 is an explanatory view showing the structure of a rotary filter.

FIG. 17 is a timing chart for explaining the operation of this embodiment.

FIG. 18 is a block diagram showing a configuration of an endoscope device.

19 to 20 are related to a sixth embodiment, and FIG. 19 is a block diagram showing a configuration of an endoscope apparatus.

FIG. 20 is an explanatory diagram showing a transmission wavelength region of each filter of the rotary filter.

FIG. 21 is an explanatory diagram showing a configuration of a rotary filter according to a seventh embodiment.

22 to 23 relate to the eighth embodiment, and FIG. 22 is a block diagram showing a configuration of an endoscope apparatus.

FIG. 23 is a block diagram showing a configuration of an image processing unit.

24 to 27 are related to the ninth embodiment, and FIG. 24 is an explanatory diagram showing transmission wavelength characteristics of each filter of the rotary filter.

FIG. 25 is an explanatory diagram showing a transmission wavelength characteristic of a band limiting filter provided in a filter turret.

FIG. 26 is a wavelength characteristic diagram of illumination light when the band limiting filter 54 is inserted in the optical path.

FIG. 27 is a wavelength characteristic diagram of illumination light when the band limiting filter 55 is inserted in the optical path.

28 to 33 relate to the tenth embodiment,
FIG. 28 is an explanatory diagram showing the configuration of the endoscope device.

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

FIG. 30 is a characteristic diagram showing transmission characteristics of each transmission filter of the rotary filter.

FIG. 31 is an explanatory diagram showing a configuration of a signal processing circuit.

FIG. 32 is an explanatory diagram showing a configuration of a color separation filter array.

FIG. 33 is an explanatory diagram showing transmission wavelength characteristics of each transmission filter of the color separation filter array.

34 to 35 relate to an eleventh embodiment,
FIG. 34 is a characteristic diagram showing transmission wavelength characteristics of each filter of the rotary filter.

FIG. 35 is an explanatory diagram showing a configuration of a signal processing circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope 6 ... Video processor 7 ... Monitor 15 ... Light guide 16 ... Lamp 18 ... Rotation filter 18a, 18b, 18c ... R, G, B filters 19 ... CCD 23 ... Selector 24r, 24g, 24b ... R, G, B memory

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 11, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

As a method for obtaining the information on the oxygen saturation, the oxygen saturation can be obtained by using a narrow band filter having the wavelength as disclosed in JP-A-63-311937 and JP-A-1-280442. There has been proposed an endoscopic device that obtains the information of.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

Therefore, 650 nm transmitted through the R filter
The light including the light of the wavelength is radiated into the body cavity, for example, and the image obtained by the reflected light is stored in the R memory 24r. That is, the image stored in the R memory 24r includes image information in which the change in the absorbance of blood is strongly reflected. Since the change in the absorbance of blood depends on the change in the oxygen saturation of hemoglobin as described above, when the oxygen saturation of hemoglobin changes, the image updated in the R memory 24r captures the change. Has become an image
It

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0077

[Correction method] Change

[Correction content]

It should be noted that a signal processing circuit similar to the signal processing circuit shown in FIG. 23, for example, may be inserted and connected at the subsequent stage of the endoscope apparatus of this embodiment to perform the emphasis processing.

Claims (1)

[Claims] 1. An endoscope having at least an imaging optical system, an imaging means for imaging a subject image formed by the imaging optical system, and a plurality of wavelengths of the subject image for obtaining an image in a visible region. A first wavelength separation means for separating an image of a region, and an image of a wavelength band in which the amount of light incident on the light receiving portion of the imaging means changes due to a change in the oxygen saturation of hemoglobin, and the first The second wavelength separation means provided integrally with or separately from the second wavelength separation means, and at least a part of the first wavelength separation means and the second wavelength separation means.
And a wavelength separation means of (1) to obtain an image in the visible region including information on the oxygen saturation level of hemoglobin.