JP2954596B2 - Endoscope device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improved image that can be selected and observed, for example, between an image showing a change in the amount of hemoglobin in blood, oxygen saturation, and the like, and an ordinary image. The present invention relates to an endoscope apparatus.

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

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

By the way, it is known that knowing the amount of hemoglobin in blood and the distribution of oxygen saturation is useful for early detection of a lesion and the like. As a method of obtaining the amount of hemoglobin in blood and the oxygen saturation, there is a method of obtaining from a plurality of images of specific wavelength regions related to hemoglobin in blood.

[Problems to be Solved by the Invention] However, in a conventional apparatus using these methods, for example, when observing an image representing a change in the amount of hemoglobin or oxygen saturation in blood and a normal image in the visible region, However, when a plurality of filter groups having different light transmission characteristics are arranged on the same radius on one rotating filter, the irradiation period of each filter illumination light becomes short, and as a result, the amount of illumination light decreases. was there. Further, even when the plurality of filter groups having different light transmission characteristics can be arranged on the illumination optical path as different rotation filters, there is a disadvantage that the apparatus becomes large because a plurality of rotation filters are required. Was.

The present invention has been made in view of these circumstances, and does not reduce the amount of illumination and the change in, for example, the amount of hemoglobin or oxygen saturation in blood without reducing the amount of illumination. It is an object of the present invention to provide an endoscope apparatus capable of selecting and displaying an image to be displayed and a normal image in a visible region.

[Means for Solving the Problems] To achieve the above object, an endoscope apparatus according to the present invention is an endoscope apparatus that sequentially irradiates illumination light of different wavelength ranges based on illumination light generated from a light source lamp. In the first, a rotary filter formed in a disk shape and rotated in the circumferential direction, and a plurality of filters capable of transmitting light of different wavelength ranges for the first image are formed on the same radius of the rotary filter.
And a plurality of filters provided inside the first filter group and capable of transmitting light of different wavelength ranges for the second image are formed on the same radius of the rotating filter. A second filter group having a light transmission characteristic different from that of the first filter group and the rotating filter are moved, and at least the first filter group or the second filter group can be located on the optical path of the illumination light Filter group switching means, and corresponding to the first image by light of a different wavelength range for the first image or the second image by light of a different wavelength range for the second image corresponding to the filter group switching means. Image display means for displaying the second image.

[Operation] The rotating filter is moved by the filter group switching means, and the first filter group formed on the same radius on the rotating filter, or formed on the same radius of the rotating filter inside the first filter group. A second filter group having a light transmission characteristic different from that of the first filter group is selectively positioned on the optical path of the illumination light; Irradiation light of each wavelength range of the filter group is arbitrarily switched for irradiation. And
An image corresponding to the switched filter group, for example, an image representing a change in the amount of hemoglobin in blood, oxygen saturation, or the like, and a normal image can be selected and observed.

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

1 to 10 relate to a first embodiment of the present invention, FIG. 1 is a block diagram showing a configuration of an endoscope apparatus, FIG. 2 is an explanatory view showing a rotary filter, and FIG. FIG. 4 is a side view showing the entire mirror device, FIG. 4 is an explanatory diagram showing a change in blood absorbance due to a change in oxygen saturation of hemoglobin, and FIG. 5 is a transmission wavelength range of each filter for a special image of a rotating filter. FIG. 6 is an explanatory diagram showing another example of the transmission wavelength range of each filter for a special image of the rotating filter, and FIG. 7 is an explanatory diagram showing the spectral transmission characteristics of each filter for normal observation of the rotating filter. , FIG. 8 is an explanatory diagram showing the spectral transmission characteristics of each filter for a special image of the rotation filter, FIG. 9 is a block diagram showing a processing circuit for obtaining the amount of hemoglobin and oxygen saturation, and FIG. Other processing circuits to determine the amount of oxygen and oxygen saturation It is a block diagram showing an example.

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

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

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

On the other hand, the video processor 6 is provided with a lamp 21 that emits light in a wide band from ultraviolet light to infrared light. As the lamp 21, a general xenon lamp, a strobe lamp, or the like can be used. The xenon lamp and the strobe lamp emit a large amount of ultraviolet light and infrared light as well as visible light. This lamp 21 is connected to a power supply 22
Is supplied with power. A rotary filter 50 driven by a motor 23 is provided in front of the lamp 21. This rotary filter 50
As shown in FIG. 2, it has three parts that are concentrically divided. A filter 51 for transmitting light in the red (R), green (G), and blue (B) wavelength regions for normal observation is provided at the outermost periphery.
a, 51b, 51c are arranged on the same radius along the circumferential direction,
In the center, filters 52a, 52b, 52c that transmit light in a narrow band centered on wavelengths λ11, λ12, λ13 for special images are arranged on the same radius along the circumferential direction. In the peripheral portion, filters 53a, 53b, and 53c that transmit light in a narrow band around the wavelengths λ21, λ22, and λ23 for special images are arranged on the same radius in the circumferential direction.

The transmission characteristics of the filters 51a, 51b, 51c are shown in FIG. On the other hand, the wavelengths λ11, λ12, λ13 and the wavelength λ2
1, .lambda.22 and .lambda.23 are set as shown in FIG.
That is, as shown in FIG. 5, a set of wavelength groups for special images such as λ11, λ12, λ13, etc., is a wavelength at which the absorbance of blood changes due to the change in the oxygen saturation of hemoglobin (also referred to as SO ₂ ). , For example, λ12 and its vicinity, and SO ₂
, A combination of wavelengths, for example, λ11 and λ13, in which the change in blood absorbance is small due to the change in the light absorption.

FIG. 5 shows the spectral absorption characteristics of oxy (oxidized) hemoglobin and deoxy (reduced) hemoglobin in order to show the change in blood absorbance due to the change in SO ₂ .

Also, the change in absorbance of the blood (scattered reflection spectrum) due to changes in SO ₂ in the vicinity of 500 to 600 nm, shown in Figure 4. As a group of wavelengths for a special image in this band, for example, a set of 569 nm, 577 nm, and 586 nm is selected as shown in FIG.

As shown in FIG. 5, in the wavelength range of 300 to 1000 nm, the wavelength group for the special image includes the λ in the wavelength range of 300 to 400 nm.
11, λ12, λ13, λ21, λ22, λ23 around 400nm
Besides, λ31, λ32, λ33 at 400 to 500 nm, 500 to 6
Λ41, λ42, λ43 at 00 nm, λ5 at 450-850 nm
1, λ52, λ53, etc. can also be set.
As the transmission wavelengths of the filters 52a, 52b, 52c and 53a, 53b, 53c in the central part and the innermost peripheral area, the λ11, λ12, λ1
The wavelength group is not limited to 3 and λ21, λ22, λ23, and, for example, an arbitrary wavelength group among the above-described five wavelength groups can be selected.

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

In this embodiment, a filter switching device 55 controlled by a control signal from the switching circuit 43 is provided. The filter switching device 55 is provided with the rotary filter 50 with respect to the optical axis of the illumination optical path between the lamp 21 and the light guide 14 entrance end.
And, by changing the position of the motor 23, any one of the outermost peripheral portion, the central portion, and the innermost peripheral portion of the rotary filter 50 is selectively interposed in the illumination optical path. .

The light transmitted through the rotary filter 50 and separated in time series into light of each wavelength region in the selected wavelength group is incident on the incident end of the light guide 14, and the leading end is transmitted through the light guide 14. The light is guided to the section 9, emitted from the tip 9, and illuminates the observation site.

The return light from the observation site due to the illumination light is imaged on the solid-state imaging device 16 by the objective lens system 15, and is photoelectrically converted. This solid-state imaging device 16 includes:
A driving pulse from a driver circuit 31 in the video processor 6 is applied via the signal line 26, and reading and transferring are performed by the driving pulse. The video signal read from the solid-state imaging device 16 is
The signal is input to a preamplifier 32 provided in the video processor 6 or the electronic endoscope 1 via the signal line 27. The video signal amplified by the preamplifier 32 is input to a process circuit 33, subjected to signal processing such as γ correction and white balance, and is subjected to an A / D converter 34.
Is converted into a digital signal. The digital video signal is supplied by a select circuit 35 to three memories (1) 36a, memories (2) 36b, and memories (3) corresponding to, for example, each color of red (R), green (G), and blue (B). 36c is selectively stored. The memory (1) 36a, the memory (2) 36b, and the memory (3) 36c
Are read out at the same time, converted into analog signals by the D / A converter 37, output as R, G, B color signals, input to the encoder 38, and output as NTSC composite signals from the encoder 38. It has become.

Then, the R, G, B color signals or the NTSC composite signals are input to a color monitor 7, and the color monitor 7 displays the observation region in color.

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

In this embodiment, the switching circuit 43 includes a filter switching device.
55, and when the outermost peripheral portion of the rotary filter 50 is interposed in the illumination optical path, light emitted from the lamp 21 is filtered through the R, G, and B filters 51a, 51b, 51a, 51b, 51c
Are sequentially transmitted, and are divided in time series into lights of R, G, and B wavelength regions. And this R, G, B light is the light guide 1
The light is transmitted to the distal end portion 9 via 4 and illuminated on the subject. The return light from the subject due to the R, G, B field sequential illumination light in the visible band is formed on the solid-state imaging device 16 by the objective lens system 15, and the solid-state imaging device 16 captures the subject image. Therefore, a normal visible image is displayed in color on the monitor 7.

On the other hand, when the filter switching device 55 is controlled by the switching circuit 43 and the central portion or the innermost peripheral portion of the rotary filter 50 is interposed in the illumination optical path, the light emitted from the lamp 21 is Filters 52a, 52b, 52 transmitting the wavelength group (λ11, λ12, λ13) or (λ21, λ22, λ23) of the filter 50
c or sequentially passes through 53a, 53b, and 53c, and is divided in time series into light of each wavelength region in the wavelength group. Then, this light is transmitted to the distal end portion 9 via the light guide 14, and is irradiated on the subject. The return light from the subject due to the illumination light is formed on the solid-state imaging device 16 by the objective lens system 15, and the solid-state imaging device 1 captures a subject image. Therefore, the monitor 7 displays the wavelength groups (λ11, λ12, λ
13) or an image according to (λ21, λ22, λ23) is displayed in pseudo color. With this image, it is possible to observe changes in SO ₂ and hemoglobin amounts.

By selectively reading one or two of the memories 36a, 36b and 36c, it is also possible to obtain an image in one or two wavelength ranges of the wavelength group.

Further, when selecting the special image, said R from the video processor 6, G, B signals, by processing by the signal processing circuit 60 as shown in FIG. 9, an image showing SO ₂ and the amount of hemoglobin It is possible to obtain

Let λ1, λ2, λ3 be each wavelength in the selected wavelength group,
The signal processing circuit 60 will be described. The wavelength λ
1, [lambda] 3 is the wavelength, the wavelength λ2 of absorbance unchanged at all the SO ₂ is the wavelength at which the absorbance by SO ₂ largely changes.

The signal processing circuit 60 has three selectors 61a, 61b, and 61c each having three inputs and one output. At each input terminal of each selector, an image signal corresponding to each wavelength in the selected wavelength group is provided. Is applied. Each of the selectors selects and outputs an image signal corresponding to a different wavelength. For example, the selector 61a outputs an image signal corresponding to the wavelength λ1, and the selector 61b outputs the image signal corresponding to the wavelength λ2.
, And the selector 61c outputs an image signal corresponding to the wavelength λ3.
The outputs of the selectors are respectively inverted gamma correction circuits 62a,
62b and 62c, and the video processor 6
Since the correction has been performed, the inverse γ correction is performed to restore the correction. Outputs of the inverse γ correction circuit are input to level adjustment circuits 63a, 63b, 63c, respectively. The level of this level adjustment circuit is adjusted by a level adjustment control signal from a level adjustment control signal generation circuit 64, and the entire level is adjusted by three level adjustment circuits 63a, 63b, and 63c. Further, for example, the vertical axis of the graph showing a change in blood absorbance due to a change in oxygen saturation as shown in FIG.
Because of the axis, the output of the level adjustment circuit is logarithmically converted by log amplifiers 65a, 65b, 65c, respectively.

Outputs of two log amplifiers 65a and 65b of the three log amplifiers are input to a differential amplifier 66a so that a difference between an image signal corresponding to the wavelength λ1 and an image signal corresponding to the wavelength λ2 is calculated. Has become. Similarly, the outputs of the two log amplifiers 65b and 65c are input to the differential amplifier 66b, and the wavelength λ
The difference between the image signal corresponding to 2 and the image signal corresponding to the wavelength λ3 is calculated. Thus, from the difference between the image signals corresponding to the two wavelengths, it is possible to know how much oxygen is dissolved in the subject, that is, the oxygen saturation. In addition, the fact that a large amount of oxygen is dissolved means that a large amount of oxygen is consumed, and thus, it is possible to know how much the blood flow is.

The differential amplifier 66a, the output of 66b is used to determine the oxygen saturation SO _2, is input to a divider 67, the divider
By performing a predetermined calculation at 67, the SO ₂ is obtained. The output of the differential amplifier 66b is used to determine the blood flow and hemoglobin amount. The output of the divider 67 and the output of the differential amplifier 66b are connected to a two-input selector 68.
Is input to, from the selector 68, so that the signal and blood flow showing an SO _2, one signal indicating the amount of hemoglobin is selectively output.

When the output signal of the selector 68 is used for measurement, it is taken out as it is, while when it is displayed,
The γ correction is performed again by the γ correction circuit 69 and output to the monitor.

In the signal processing circuit 70 shown in FIG. 10, the signal processing circuit 60 shown in FIG.
Processing is performed by software (that is, by a microcomputer). That is, the signal processing circuit 70 has three memories 71a, 71b, and 71c for respectively storing image data corresponding to the respective wavelengths in the selected wavelength group. is input to the processor 72, by the microprocessor 72, SO ₂ or, a predetermined calculation for determining blood flow, the amount of hemoglobin is performed.

In the case of observing and measuring the blood flow, in FIG. 6, a and b, b and c, or b and d of the wavelength regions indicated by a, b, c, and d are used. A combination may be used.

As described above, in the present embodiment, by changing the positions of the rotation filter 50 and the motor 23 with respect to the optical axis of the illumination light path, the combination of wavelengths that separates the illumination light in time series is represented by (R, G, B). , (Λ11, λ12, λ13), (λ21, λ22, λ2
It can be selected from the three wavelength groups of 3). Therefore, by selecting the optimal wavelength region according to the observation site, the observation purpose, and the like, the normal image and the image showing changes in the oxygen saturation and amount of hemoglobin in blood in different wavelength regions, blood flow, and the like are switched. Can be observed. In addition, filters 51a, 51b, and 51c that transmit light in the wavelength region for normal observation are transmitted to the outermost peripheral portion of the rotary filter 50, and light in the wavelength region for special images is transmitted to the central portion and the innermost peripheral portion. Filters 52a, 52b,
Since 52c and the filters 53a, 53b, 53c are arranged on the same radius along the circumferential direction, all the filters having different light transmission characteristics are arranged along the circumferential direction of the rotary filter as in the related art. It is not necessary to provide them on the same radius, the aperture ratio of the filters can be increased, and as a result, the irradiation period of the illumination light of each filter becomes longer, and a sufficient amount of illumination light can be obtained. In addition, since a sufficient amount of illumination light can be obtained, the size of the lamp 21 can be reduced.

In addition, since the light transmission characteristics to the mucous membrane differ depending on each wavelength group, the observed or measured image varies depending on the change in the thickness direction of the mucous membrane depending on the selected wavelength group. Thus, for example, by comparing taking the difference between the images showing the SO ₂ and hemoglobin amount for each wavelength group,
Observation and measurement of changes in the amount of SO ₂ and hemoglobin from the very surface of the mucous membrane to changes in the interior of the mucosa are possible. Observation and measurement of three-dimensional changes in SO ₂ and hemoglobin including the thickness direction of the mucous membrane are possible. Become. This has an effect that it is useful for early detection of a lesion and determination of an infiltration range.

The number of wavelength groups provided in the rotary filter 50 is not limited to three, and may be any number as long as it is plural.

The present invention is not limited to the above-described embodiment. For example, the combination of the wavelength region groups is not limited to those shown in FIGS. 5 and 6, and any combination is possible.

Further, the present invention is not limited to the one that receives the reflected light of the object to be observed, but may be the one that receives the light transmitted through the object to be observed.

In addition, the present invention is not limited to an electronic endoscope having a solid-state imaging device at the distal end of the insertion portion, and may be replaced with an eyepiece of an endoscope such as a fiberscope capable of observing the naked eye or with the eyepiece. Thus, the present invention can also be applied to an endoscope apparatus used by connecting a television camera.

[Effects of the Invention] As described above, according to the present invention, illumination light of each wavelength region of the first filter group and illumination light of each wavelength region of the second filter group can be easily emitted as illumination light. For example, an image representing a change in the amount of hemoglobin in blood or oxygen saturation and an image in the visible region can be selected and observed.

Furthermore, since the outermost peripheral portion, the central portion, and the innermost peripheral portion of the rotary filter can each include a filter group having different light transmission characteristics, the aperture ratio of the filter can be increased,
As a result, the illumination light irradiation period of each filter is lengthened, and a sufficient illumination light amount can be obtained. Further, since a sufficient amount of illumination light can be obtained, the size of the lamp can be reduced, and the size of the device itself can be reduced.

[Brief description of the drawings]

1 to 10 relate to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of the endoscope apparatus, FIG. 2 is an explanatory view showing a rotary filter, FIG. 3 is a side view showing the entire endoscope apparatus, and FIG. 4 is a change in oxygen saturation of hemoglobin. FIG. 5 is an explanatory diagram showing a change in the absorbance of blood due to a change in blood, FIG. 5 is an explanatory diagram showing a transmission wavelength range of each filter for a special image of a rotating filter, and FIG. FIG. 7 is an explanatory diagram showing the spectral transmission characteristics of each filter for normal observation of the rotating filter, and FIG. 8 is a graph showing the spectral transmission characteristics of each filter for a special image of the rotating filter. FIG. 9 is a block diagram showing a processing circuit for calculating the amount and oxygen saturation of hemoglobin, and FIG. 10 is a block diagram showing another example of a processing circuit for calculating the amount and oxygen saturation of hemoglobin. It is. DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope, 6 ... Video processor 7 ... Monitor, 15 ... Objective lens system 16 ... Solid-state image sensor, 21 ... Lamp 50 ... Rotating filter 55 ... Filter switching device

Continuation of the front page (56) References JP-A-62-111227 (JP, A) JP-A-62-182705 (JP, A) JP-A-62-217216 (JP, A) JP-A-62-174716 (JP) JP-A-61-114176 (JP, A) JP-A-55-63300 (JP, A) JP-A-61-151705 (JP, U)

Claims (1)

(57) [Claims] An endoscope apparatus for sequentially irradiating illumination light of different wavelength ranges based on illumination light generated from a light source lamp, comprising: a rotating filter formed in a disk shape and rotated in a circumferential direction; A first filter group formed on the same radius as the rotary filter, and a plurality of filters for transmitting light in different wavelength ranges for an image, provided inside the first filter group; A second filter group having a light transmission characteristic different from that of the first filter group, wherein a plurality of filters capable of transmitting light in different wavelength ranges are formed on the same radius of the rotating filter; Filter group switching means for moving a rotary filter so that at least the first filter group or the second filter group can be positioned on the optical path of the illumination light; and the first group corresponding to the filter group switching means. An image display means for displaying a first image formed by light in a different wavelength range for an image or a second image formed by light in a different wavelength range for the second image. apparatus.