JP3315188B2 - Endoscope device - Google Patents

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 indicating a change in hemoglobin oxygen saturation for early detection of a lesion or the like.

[0002]

2. Description of the Related Art In recent years, by inserting an elongated insertion portion into a body cavity, it is possible to observe internal organs in the body cavity or perform various treatments using a treatment tool inserted into a treatment tool channel as necessary. Endoscopes are widely used.

[0003] Various electronic endoscopes using a solid-state imaging device such as a charge-coupled device (CCD) as imaging means have also been proposed.

Recently, the above-mentioned electronic endoscope has
An endoscope device for observing changes in lesions and mucous membranes that was difficult to observe with a conventional fiberscope,
Proposed.

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, wavelengths at which the absorbance does not change due to changes in oxygen saturation, such as 569 nm and 586 nm, and wavelengths which greatly change due to changes in oxygen saturation, such as 577 nm, There is a method of measuring the change in oxygen saturation in the mucous membrane based on the difference between the two.

As a method of obtaining the information on the oxygen saturation, for example, as described in Japanese Patent Application Laid-Open Nos. 63-31937 and 1-280442, the oxygen saturation is obtained by using a narrow-band filter having the above wavelength. An endoscope apparatus that obtains such information has been proposed.

[0007]

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

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 oxygen saturation of hemoglobin even during normal visual observation. It is an object.

[0009]

An endoscope apparatus according to the present invention comprises:
An endoscope having at least an imaging optical system, and an imaging unit that captures a subject image formed by the imaging optical system,
The imaging means converts a visible light subject image of a plurality of wavelength ranges into the wavelength range to obtain an image of the visible range of the subject.
The first wavelength separating means obtained for each, and the imaging means,
Absorbance increases due to changes in hemoglobin oxygen saturation
A second wavelength separating unit for obtaining a subject image of light in a changing wavelength band, and the first wavelength separating unit .
At least one wave of the subject image for each wavelength region
An image in the visible region obtained using the subject image in the long region ,
A wave whose absorbance changes greatly due to a change in the oxygen saturation of the hemoglobin obtained by the second wavelength separating means.
An image recording means for storing a subject image of long-band light, and an image in a visible region including information on the oxygen saturation of hemoglobin of the subject by synchronizing each image stored in the image recording means. Control means for obtaining
It is characterized by.

[0010]

[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 configuration diagram showing the entire endoscope device, FIG. 2 is a block diagram showing the configuration of the endoscope device, and FIG. 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 according to the present embodiment includes an electronic endoscope 1 as shown in FIG. This electronic endoscope 1
It has an elongated and flexible insertion section 2, for example, and a large-diameter operation section 3 is connected to the rear end of the insertion section 2. The operation unit 3
A flexible universal cord 4 is extended laterally from the rear end side, and a connector 5 is provided at an end of the universal cord 4. The electronic endoscope 1 is connected via the connector 5 to a video processor 6 in which a light source device and a signal processing circuit are built.
Further, a monitor 7 and an image filing device 8 are 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 and adjacent to the distal end portion 9 are sequentially provided. The operation unit 3
By rotating the bending operation knob 11 provided on the, the bending portion 10 can be moved in the horizontal direction or the vertical direction,
It can be bent. 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. 2, a light distribution lens 13 and an image forming optical system 14 are disposed at the distal end portion 9. A light guide 15 made of a fiber bundle is continuously provided on the rear end side of the light distribution lens 13.
5 is the insertion part 2, the operation part 3, the universal cord 4
And is connected to the connector 5. By connecting the connector 5 to the video processor 6, illumination light emitted from a light source device in the video processor 6 is incident on the incident end of the light guide 15.

The light source device includes a lamp 16 and a rotary filter 18 disposed in an illumination light path of the lamp 16 and rotated by a motor 17. The lamp 16 emits light from ultraviolet to infrared. The rotating filters 18 include filters 18a and 18 that transmit light in different wavelength ranges, respectively.
b, 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.
Accordingly, the light is separated into respective wavelength regions in a time series and is incident on the incident end of the light guide 15.
This illuminating light is transmitted by the light guide 15 to the distal end 9.
And is emitted from the front end surface, passes through the light distribution lens 13, and irradiates the subject.

On the other hand, a solid-state image sensor, for example, a CCD 19 is provided at an image forming position of the image forming optical system 14. Then, the subject image illuminated by the plane-sequential illumination light is formed by the imaging optical system 14,
It is converted into an electric signal by the CD 19. This CCD 19
Image signals from a predetermined range of electric signals (for example, 0
(Up to 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 one-input three-output selector 23. R sent in chronological order
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 unit 24 corresponding to R, G, B.
b. Each memory 24r, 2
The image signals read from 4g and 24b are respectively
The signals are converted into analog signals by the D / A converters 25r, 25g, and 25b, and the R, G, and B signal output terminals 26, 27, and 2 are output.
8 is output. In addition, the R,
The synchronization signal SYNC from the synchronization signal generation circuit 29 is output from the synchronization 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.

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

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

The light from the ultraviolet to the infrared 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.

With respect to the R filter as the first wavelength separating means and the second wavelength separating means, the reflection spectral characteristic due to the change in the oxygen saturation of hemoglobin is compared with the transmission light area of the G and B filters. It transmits red light including around 650 nm where the change is remarkable. Further, since the R filter has a wider transmission wavelength region 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 the R filter lower than the transmittance of the G and B filters,
Prevents red saturation. The G and B filters constitute first wavelength separating means.

The light from the lamp 16 is time-sequentially decomposed into light having a wavelength corresponding to each of the filters 18a, 18b, and 18c. Is illuminated into the body cavity as illumination light. A subject image by each illumination light is formed by an imaging optical system 14.
Thus, an image is formed on the CCD 19 and converted into an electric signal. The output signal of the CCD 19 is amplified by an amplifier 20 and converted to a predetermined γ characteristic by a γ correction circuit 21. The output of the gamma correction circuit 21 is converted into a digital signal by an A / D converter 22, passed through a selector 23, and decomposed into respective wavelengths in a time-series manner.
4g and 24b. That is, in the selector 23, the output is switched 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 D / A converters 25r, 25g, 25b, and output as R, G, B signals. You.

Here, the change in the oxygen saturation of hemoglobin changes the reflection spectral characteristics of hemoglobin. That is, the change in the reflection spectral characteristic (absorbance) of the blood,
Conventionally known. 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 greatly changes due to a change in oxygen saturation of hemoglobin. Therefore, this 65
By illuminating with light in the wavelength range including near 0 nm,
The image in which the change in oxygen saturation of hemoglobin can be observed,
Will be obtained. That is, in the present embodiment, the R
Light transmitted through the filter is light in a wavelength region including around 650 nm.

Therefore, 650 nm transmitted through the R filter
The light containing the light having the wavelength of? That is, the image stored in the R memory 24r includes image information that strongly reflects changes in blood absorbance. 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 the hemoglobin changes, the image updated in the R memory 24r captures the change. Image
You.

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. It is possible to clearly determine the degree of saturation, that is, a diseased part where the change in oxygen saturation in blood is remarkable, and it is possible to improve diagnostic ability.

FIGS. 5 to 7 relate to a second embodiment of the present invention. FIG. 5 is a block diagram showing a configuration of an endoscope apparatus, FIG. 6 is an explanatory view showing a rotary filter, and FIG. FIG. 3 is an explanatory diagram illustrating a transmission wavelength region 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
In place of the selector 33 having one input and four outputs and the memory 2
A selector 35 is provided in the succeeding stage of the memory 34 and the memories 34a and 34r instead of the selector 34. In addition, the same configurations and operations as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

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

The filters 32b, 32c, 32d are
The filter 32a is a filter that transmits light in a wavelength range that allows visible observation, and the filter 32a has a reflection spectral characteristic of 650 nm in which the reflectance spectral characteristic is significantly changed due to a change in the oxygen saturation of hemoglobin.
This is a filter that transmits light in a nearby wavelength range. 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 or the like (not shown), a selection is made between observation with an RGB image and observation with an R′GB image. Has become. That is, the selector 35 selects one of the memories 34a and 34r based on the select signal.

The video signals read from the memories 34a, 34g, 34b or 34r, 34g, 34b are synchronized, converted into analog signals by the D / A converter 25, and converted into 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 switch or the like to switch the observation image.

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

FIGS. 8 to 12 relate to a third embodiment of the present invention. FIG. 8 is a block diagram showing the configuration of an endoscope apparatus.
Is an explanatory diagram showing the configuration of the filter turret, FIG. 10 is an explanatory diagram showing the transmission wavelength region of each filter of the rotary filter,
FIG. 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, a first wavelength separating means having filters 36a, 36b and 36c having a transmission wavelength region as shown in FIG. Rotating filter 36
Are provided. Further, a filter turret 37 having a configuration as shown in FIG. 9 is inserted on the light path on the lamp side of the rotary filter 36.

The filter turret 37 is a first wavelength band limiting filter 39 constituting a first wavelength separating means.
And a second wavelength band limiting filter 40 as 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 includes a motor 38
By the rotation of the first wavelength band limiting filter 39 or the second wavelength band limiting filter 40 on the optical path,
It is to be inserted.

In the present embodiment, the second wavelength band limiting filter is constituted by two filters, but a single filter having a transmission wavelength region as shown in FIG. 12 may be used. In addition, the same configurations and operations as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

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

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

When the first wavelength band limiting filter 39 is arranged on the optical path, R and R shown in FIG.
Light in the G and B wavelength regions is radiated in time series. When a second wavelength band limiting filter 40 having a transmission wavelength range as shown in FIG. 12 is inserted on the optical path, R ', G, B shown in FIG. 7 of the second embodiment.
Are radiated in time series.

If the rotation of the motor 38 is controlled by an instruction given from a front panel or the like (not shown), 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 operations and effects are the same as those of the first and second embodiments, and the description is omitted.

FIGS. 13 to 15 relate to a fourth embodiment of the present invention. FIG. 13 is an explanatory view showing the structure and operation of a rotary filter, and FIG.
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, a rotary filter 41 having a configuration as shown in FIG. 13 is provided instead of the rotary filter 18 in the first embodiment.

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

FIG. 13A shows the rotary filter 41 when the fan-shaped R, R 'filter 41A is removed. In this state, G and B filters 41c and 41d and a portion 41e without a filter are arranged in the filter 41. Stoppers 42, 42 are provided on both sides of the side face of the unfiltered portion 41e and are spaced apart by half the length of the circumferential portion of the R, R 'filter.

As shown in FIGS. 13B and 13C, the R, R 'filter 41A has a structure that can be slid 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
e is an R filter 41a or an R 'filter 41b
However, it has the structure which opposes. In addition, the same configurations and operations as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

Next, the operation of the present embodiment will be described with reference to FIG. The rotary filter 41 is a rotary filter having the above-described configuration, and corresponds to FIG. 7 of the second embodiment.
Can be illuminated in a time series with the illumination light of the wavelength region as shown in R, G, B and the light of R ', G, B.

For example, from the front panel or the like,
When an instruction to select to illuminate the G and B wavelength regions is output, the rotating filter 41 rotates to the left as shown in FIG.
A tilts to the right, indicating that the R filter 41a has been 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 rotation filter 4
1 rotates to the right as shown in FIG.
The fan-shaped R, R 'filter 41A tilts to the left, indicating that the R' filter 41b has been selected. Therefore, R ',
The G and B illumination lights are sequentially illuminated. As described above, an RGB image and an R′GB image are obtained.

The other functions and effects are the same as those of the first and second embodiments, and the description is omitted.

FIGS. 16 to 18 relate to a fifth embodiment of the present invention. 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, and FIG. FIG. 2 is a block diagram illustrating a configuration of the endoscope device.

In this embodiment, a rotary filter 43 having a configuration as shown in FIG. 16 is provided instead of the rotary filter 18 in the first embodiment. The rotary filter 43 is provided with filters 43a, 43b and 43c having wavelength transmission characteristics as shown in FIG. 7 of the second embodiment. The R and R 'filters 43a constituting the second wavelength separating means and the first wavelength separating means are the G and B filters 43b and 43c constituting the first wavelength separating means.
Is formed in half the size of Further, as shown in FIG. 18, a read control circuit 44 is connected to the CCD 19. In addition, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

Next, the operation of the present 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. The CCD 19 receives reflected light from the subject and converts the light 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 response to a read selection instruction from the front panel or the like, and executes the CC at a selected predetermined timing.
D19 is read. The read output signal of the CCD 19 is sent to a signal processing circuit after the amplifier 20 and subjected to the same processing as described above.

FIG. 17 shows the predetermined timing of reading in the read control circuit 44. RGB
When an image is obtained, the predetermined timing is as shown in FIG.
As shown in (b), an electric signal captured at the timing of R, G, and B illumination light is read. On the other hand, when R ', G, and B images are obtained, the predetermined timing is such that an electric signal imaged at the timing of R', G, and B illumination light is read out as shown in FIG. It has become.

Other functions and effects are the same as those of the first and second embodiments, and the description is omitted.

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

In this embodiment, the rotary filter 43 of the fifth embodiment is used instead of the rotary filter 18 of the first embodiment.
Is provided. The transmission wavelength characteristics of each filter of the rotary filter 43 are as shown in FIG. Others
The same components and operations as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

Next, the operation of the present 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 rotating filter 43 is the same as that in FIG. 3 of the first embodiment. The R memory 24r stores an image obtained by the illumination light transmitted through the R and R 'filters 24a. Therefore, the operation and effect are the same as those of the first embodiment, and the description is omitted.

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

In the seventh embodiment, a rotary filter 44 having a configuration as shown in FIG. 21 is provided instead of the rotary filter 18 in the first embodiment. That is, the rotation filter 44 includes an R′R filter, a B filter,
A G filter is arranged. The transmission wavelength characteristic of each filter of the rotary filter 44 is the same as that of the first embodiment, but the transmittance is the same for all of R'R, G and B. In addition, the same configuration and operation 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 configuration as shown in FIG. 21, and the aperture ratio of the R'R filter is G, B.
Less than filters. Therefore, the illumination light illuminated in time series by the rotation filter 44 becomes illumination light having the same transmission wavelength characteristics as in FIG. 3 of the first embodiment. Therefore, other operations and effects are the same as those of the first embodiment, and the description is omitted.

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

In the endoscope apparatus according to the eighth embodiment, an image processing section 45 is interposed and connected at a stage subsequent to the D / A converter 25 in the endoscope apparatus according to the first embodiment. In addition, the configuration and operation of the endoscope apparatus are the same as those of the first embodiment, and description thereof will be omitted.

FIG. 23 is a block diagram showing the structure of the image processing section 45. The R, G, and 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 since the predetermined γ correction has been performed by the γ correction circuit 21. The output of the inverse γ correction circuit 47 is supplied to a frame memory 48 and a divider 49.
Respectively.

The divider 49 calculates R / G or R / B from the input RGB signals and outputs the result to the ROM 50. The ROM 50 performs an enhancement process 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 original image input to the frame memories 48a, 51b, and 51c and subjected to timing adjustment is subjected to enhancement conversion. The converted enhanced image is output to the γ correction circuit 52, and is subjected to a predetermined γ correction conversion. The output of the gamma correction circuit 52 is input to a D / A converter 53, converted into an analog signal, and output from the RGB signal output terminals 26, 27, 28.

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

According to the present embodiment, an enhanced image of oxygen saturation is obtained from the image obtained in the first embodiment.
It is easy to determine the oxygen supply state of a lesion or the like, which leads to improvement in diagnostic performance.

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

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

In this embodiment, the transmission wavelength characteristics of the filters 36a, 36b and 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 this embodiment includes a wavelength of 650 nm and has an upper limit of the transmission wavelength. Further, in contrast to the B filter of the third embodiment, the filter of this embodiment has the transmission wavelength ranges of B and B 'shown in FIG. Further, in contrast to the G filter of the third embodiment, the filter of the present embodiment has transmission wavelength ranges of G and G 'shown in FIG.

In this embodiment, in the filter turret 37, instead of the filters 39 and 40, a band limiting filter 5 having the characteristics shown in FIG.
4, 55 are arranged. The other configuration is the same as that of the third embodiment, and the illustration and description of the configuration of the device are omitted.

Next, the operation of the present embodiment will be described.
The band limiting filter 54 is inserted on the optical path, and the rotating filter rotates on the optical path, so that the subject is irradiated with illumination light having a transmission wavelength characteristic as shown in FIG. Also, by retracting the band-limiting filter 54 from the optical path and inserting the band-limiting filter 55 on the optical path, illumination light having a transmission wavelength characteristic as shown in FIG. That is, as shown in FIG. 26, the band limiting filter 54
Transmission characteristics including the above wavelength range. As shown in FIG. 27, the band limiting filter 55 includes a part of R, that is, a wavelength of 650 nm, and a longer wavelength side of R and B ′.
, And G ′. Therefore, due to the filter 55, the bandwidth of the R filter is narrower than that of the case where the filter 54 is inserted, and an image sensitive to a change in the oxygen saturation can be obtained.

According to this embodiment, the band limiting filter 54
Is inserted on the optical path, a normally visible observation image is obtained. On the other hand, when the band-limiting filter 55 is inserted on the optical path, an image from which a change in oxygen saturation of hemoglobin can be determined is obtained.

Further, the present embodiment can be applied not only to an image in which a change in oxygen saturation is obtained, but also to observation of a hemoglobin amount, an infrared image, and an ICG density image. The other configuration and operation and effect are the same as those of the third embodiment, and the description is omitted.

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

FIGS. 28 to 33 relate to the tenth embodiment of the present invention. FIG. 28 is an explanatory diagram showing the configuration of an endoscope apparatus, FIG. 29 is an explanatory diagram showing the configuration of a rotary filter, and FIG. 31 is a characteristic diagram showing transmission characteristics of each transmission filter, FIG. 31 is an explanatory diagram showing the configuration of a signal processing circuit, FIG. 32 is an explanatory diagram showing the configuration of a color separation filter array, and FIG. 33 is each transmission filter of the color separation filter array. FIG. 4 is an explanatory diagram showing transmission wavelength characteristics of the present invention.

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, the video processor 6 is provided with a lamp 57 that 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 the strobe lamp emit a large amount of ultraviolet light and infrared light as well as visible light. The lamp 57 is supplied with electric power by a power supply unit 58. In front of the lamp 57, a rotary filter 60 constituting first and second wavelength separating means driven to rotate by a motor 59 is provided. In this rotary filter 60, filters 60a and 60b having a 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 to be driven.

The light transmitted through the rotary filter 60 and separated in time series into the lights in the respective wavelength ranges shown in FIG. 30 or the white light illuminated by the rotary filter 60 being retracted from the optical path is The light enters the incident end of the light guide 15, is guided to the distal end portion 9 via the light guide 15, is emitted from the distal end portion 9, and illuminates the observation site.

The optical image of the object illuminated by the illumination light is formed on the imaging 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. The color separation filter array 56 includes G (green), Cy (cyan), and Ye, as shown in FIG.
(Yellow) color mosaic arrangement of three color transmission filters. FIG. 33 shows the transmission characteristics of the G, Cy, and Ye filters.

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

The LPFs 63 and 64 are, for example, 3 MHz,
It shows a cut-off characteristic of 0.8 MHz, and the signal passed 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.
, And γ correction and the like are performed. The high-frequency luminance signal YH passed through the process circuit 66 is supplied to the horizontal correction circuit 6.
After the horizontal contour correction, the horizontal aperture correction, and the like are performed in step 8, the input is input to the color encoder 69.

The luminance signal YL on the low frequency side passed through the process circuit 67 is supplied to a matrix circuit 70 for image display.
And the tracking correction is performed.

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

The chrominance signals RY and BY are generated by the matrix circuit 70, and then input to the color encoder 69, where the luminance signal obtained by mixing the luminance signals YL and YH, the chrominance signals RY and A chroma signal obtained by orthogonally modulating BY by a subcarrier is mixed, a synchronizing signal is superimposed on the mixed signal, and a composite video signal is output from an NTSC output terminal. Further, RG from the previous stage of the matrix circuit 70
The B signal is connected to the signal processing circuit 81.

The driver 82 receives a synchronizing signal from a synchronizing signal generation circuit 83, and the driver 82
Is a drive signal synchronized with the synchronization signal.
Output to

Further, in the composite video signal, the observation site is displayed in color 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 which operates in synchronization with the rotation of the rotation 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.
b.

The R and R ″ signals input to the frame memories 84a and 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 in synchronization with the G and B images stored in the frame memories 84c and 84d, respectively.

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

On the other hand, when observing a change in the oxygen saturation of the mucosal tissue, the rotary filter 60 is inserted on the optical path, and the illumination light from the filter 60a and the illumination light from the filter 60b are illuminated in a time series. Images obtained by illuminating in time series are separated into R, G, and B images, and input to the signal processing circuit 81. The signal input to the signal processing circuit 81 is obtained by subtracting the image illuminated by the filter 60a from the image illuminated by the filter 60b to obtain 650.
An R 'image similar to that illuminated with light in the wavelength range from nm to 780 nm is obtained. Since 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 output simultaneously, the change in the oxygen saturation of hemoglobin is remarkable. The resulting image will be obtained.

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

In the present embodiment, a rotary filter 87 having the characteristics shown in FIG. 33 is arranged in place of the rotary filter 60 in the endoscope apparatus of the tenth embodiment.
This rotary filter 87 is a filter 60 shown in FIG.
filters 87a, 87 provided in place of a, 60b
b, and the transmission wavelength characteristics thereof are as shown in FIG. That is, the filter 87a constituting the first wavelength separating means has a transmission characteristic in a wavelength range up to 650 nm. The filter 87b constituting the second wavelength separating means has a transmission characteristic of a narrow bandwidth centered around 650 nm.

In this embodiment, a signal processing circuit 89 shown in FIG. 34 is used instead of the signal processing circuit 81 of the tenth embodiment.
It has. The configuration of the signal processing circuit 89 is shown in FIG.
As shown in the figure, a selector 88 is provided instead of the difference circuit 86 in the tenth embodiment. In the present embodiment, the configuration shown in FIG. 28 is the same as that of the tenth embodiment, and a description thereof will be omitted. At the same time, the same components and operations as in the tenth embodiment are denoted by the same reference numerals, description thereof will be omitted, and only different points will be described.

Next, the operation of the present embodiment will be described.
During normal visible observation, the rotating 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 the oxygen saturation of the mucosal tissue, the rotary filter 87 is inserted on the optical path, and the illumination light from the filter 87a and the illumination light from the filter 87b are illuminated in time series. Images obtained by illuminating in time series are separated into R, G, and 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.
One of the selected images and the G and B images stored in the frame memories 84c and 84d are synchronized and output, thereby obtaining an image in which a change in the oxygen saturation of hemoglobin is remarkably observed. Will be done. Other functions and effects are the same as in the tenth embodiment.

The present invention is not limited to the contents of the above-described embodiment, but is based on a change in the oxygen saturation of hemoglobin.
Any wavelength may be used as long as the change in the reflection spectral characteristic is large.
It may be near.

Further, if a device such as a conventional image processing unit for performing 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. Image can be obtained. Alternatively, the image processing unit may be provided in the video processor without being independent as an image processing unit.

Further, the present invention is not limited to an electronic endoscope having a solid-state image pickup device at the end of the endoscope insertion section, but may be applied to an eyepiece of an endoscope such as a fiberscope or a rigid endoscope capable of visual observation. Alternatively, the present invention can be applied to an endoscope which is connected to an external television camera having a solid-state imaging device such as a CCD instead of an eyepiece.

[0104]

As described above, according to the present invention,
A visual observation image similar to the conventional one can be obtained, and a change in oxygen saturation of hemoglobin can be determined, and an image having almost the same color tone as the visible observation image can be obtained. In addition, it is possible to simultaneously obtain functional information of a living body from a change in the oxygen saturation of hemoglobin, and it is possible to easily observe a lesion or the like and to improve diagnostic ability.

[Brief description of the 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 apparatus.

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 a 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 relate 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.

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

FIG. 14 is a view showing R and R provided on a rotary filter.
FIG. 4 is an explanatory diagram showing a configuration of an R ′ filter.

FIG. 15 is a block diagram showing a configuration of the endoscope apparatus.

FIGS. 16 to 18 relate to a fifth embodiment, and FIG. 16 is an explanatory diagram showing a configuration 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 apparatus.

19 and 20 relate 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.

FIGS. 22 and 23 relate to an 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.

FIG. 24 to FIG. 27 relate 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 transmission wavelength characteristics of a band limiting filter provided in a filter turret.

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

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

FIG. 28 to FIG. 33 relate to a tenth embodiment,
FIG. 28 is an explanatory diagram showing a 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 illustrating 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.

FIG. 34 and FIG. 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 illustrating 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 ... Rotating filter 18a, 18b, 18c ... Each filter of R, G, B 19 ... CCD 23 ... Selector 24r, 24g, 24b ... R, G, B memory

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-280442 (JP, A) JP-A-3-121035 (JP, A) JP-A-2-191424 (JP, A) JP-A-2- 279131 (JP, A) JP-A-3-80834 (JP, A) JP-A-3-45233 (JP, A) JP-A-2-104332 (JP, A) JP-A-1-308531 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) A61B 5/145 A61B 1/00 300

Claims (1)

(57) [Claims] 1. An endoscope having at least an image forming optical system, an image pickup unit for picking up an image of a subject formed by the image forming optical system, and an image of a visible region of the object by the image pickup unit The visible light subject image in a plurality of wavelength ranges is
The first wavelength separating means obtained for each time, and the imaging means, the subject image of light in a wavelength band in which the absorbance greatly changes due to the change in oxygen saturation of hemoglobin
A second wavelength separating unit for obtaining the wavelength range, and for each of the wavelength regions obtained by the first wavelength separating unit.
Of at least one wavelength region in the subject image of
An image in the visible region obtained by using the image and a light band in a wavelength band in which the absorbance greatly changes due to a change in the oxygen saturation of the hemoglobin obtained by the second wavelength separation means.
Image recording means for storing a body image, and control means for obtaining an image in a visible region including information on the oxygen saturation of hemoglobin of the subject by synchronizing the respective images stored in the image recording means, and an endoscope apparatus comprising the.