JP2660009B2 - Endoscope device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an endoscope apparatus capable of obtaining an image in a general visible region and an image in a specific wavelength region.

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

Also, various electronic endoscopes using a solid-state imaging device such as a charge-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 determining the amount of hemoglobin and oxygen saturation in blood, for example, as shown in Japanese Utility Model Application Laid-Open No. 151705/1986, it is determined from images of a plurality of specific wavelength regions related to hemoglobin in blood. There is a way.

However, in the camera shown in the conventional example, since the observation wavelength region is fixed, a color image in the visible region is not generally obtained. For example, a special image including blood information and an image in the general visible region are not obtained. And could not be compared.

[Object of the Invention] The present invention has been made in view of the above circumstances, and provides an endoscope apparatus capable of obtaining an image in a general visible region and an image in a specific wavelength region. It is intended to be.

[Means for Solving the Problems] The endoscope apparatus according to the present invention provides a first method for obtaining a color image.
A first color separation unit (filter) capable of transmitting light in a second wavelength range for obtaining blood information and a second wavelength range for obtaining blood information, and a third color different from the first wavelength range for obtaining a color image.
A second color separation means (filter) capable of transmitting light in a fourth wavelength range different from the second wavelength range for obtaining blood information and blood information, the first color separation means and the second color separation means. An imaging unit configured to form an object image separated into different wavelength regions by a second color separation unit on an imaging surface;
Selectively restricting the wavelength region of the subject image formed on the imaging surface by the color separation unit and the second color separation unit, and the first color separation unit and the second color separation unit A wavelength region limiting unit that forms a subject image formed of a wavelength region for obtaining the blood information on the imaging surface, and a signal separation unit that separates a signal output from the imaging unit into a plurality of different color information signals. Display means for displaying a subject image based on a plurality of different color information signals separated by the signal separating means, and obtaining the blood information based on a plurality of different color information signals separated by the signal separating means. Blood information calculation means capable of calculating blood information about the subject when the subject image formed of the wavelength region is formed on the imaging surface; and the subject based on a calculation result of the blood information calculation means. It is characterized in that it has and a displayable blood information display means blood information.

[Operation] In the endoscope apparatus of the present invention, the first color separation means (filter) transmits light in a first wavelength region for obtaining a color image and light in a second wavelength region for obtaining blood information. And the second
A third wavelength region different from the first wavelength region for obtaining a color image and a fourth wavelength region different from the second wavelength region for obtaining blood information. Of light. Therefore, the subject image is separated into different wavelength regions by the first color separation means and the second color separation means.

The imaging means forms the subject images separated into the different wavelength regions on the imaging surface. At this time, the wavelength region limiting means
The first color separation unit and the second color separation unit selectively restrict a wavelength region of the subject image formed on the imaging surface by the first color separation unit and the second color separation unit. A subject image composed of a wavelength region for obtaining the blood information in the color separating means is formed on the imaging surface.

The signal separation signal separates the signal output from the imaging unit into a plurality of different color information signals, and the display unit converts the subject image based on the plurality of different color information signals separated by the signal separation unit. indicate.

Further, when the blood information calculation means is configured such that the subject image formed of the wavelength region for obtaining the blood information based on the plurality of different color information signals separated by the signal separation means is formed on the imaging surface. Blood information relating to the subject is calculated, and blood information display means displays blood information of the subject based on the calculation result of the blood information calculation means.

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

1 to 12 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 band-pass filter turret, and FIG. 4 and 5 are explanatory views showing changes in blood absorbance due to changes in hemoglobin oxygen saturation, and FIG. 6 is a transmission wavelength region of each filter of the rotary filter. 7 to 11 are explanatory diagrams showing transmission wavelength ranges of respective filters of the band-pass filter turret, and FIG. 12 is a block diagram showing a processing circuit for obtaining the amount of hemoglobin and the oxygen saturation. It is.

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. These signal lines 26 and 27 are inserted into the insertion section 2 and the universal cord 4 and connected to the connector 5.

On the other hand, the video processor 6 is provided with a lamp 21 that emits light in a wide band from ultraviolet light to infrared light. As the lamp 21, a general xenon lamp, a strobe lamp, or the like can be used. The xenon lamp and the strobe lamp emit a large amount of ultraviolet light and infrared light as well as visible light. This lamp 21 is connected to a power supply 22
Is supplied with power. A rotary filter 50 driven by a motor 23 is provided in front of the lamp 21. In the rotary filter 50, filters for transmitting light in the respective red (R), green (G), and blue (B) wavelength regions for normal observation are arranged along the circumferential direction. FIG. 6 shows the transmission characteristics of each filter of the rotary filter 50. As shown in this figure, in this embodiment, the filter transmitting B is 800 nm in the infrared band.
The filter that transmits G also has a double transmission characteristic that transmits the wavelength region B ′ of about 900 nm or more in the infrared band.

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

Further, a band-pass filter turret is provided on the illumination optical path between the rotary filter 50 and the light guide 14 entrance end.
51 are arranged. As shown in FIG. 2, the band-pass filter turret 51 includes five types of filters 51a, 51b, 51c, 51d, and 51 having different band-pass characteristics.
e is arranged along the circumferential direction. Each filter 51a ~
The transmission characteristics of 51e are shown in FIGS. 7 to 11.

That is, as shown in FIG.
It transmits through a narrow band centered at nm and a narrow band centered at 650 nm. The filter 51b is, as shown in FIG.
It transmits a narrow band centered at nm and wavelengths of 900 nm and above. As shown in FIG. 9, the filter 51c transmits a narrow band near 580 nm, a narrow band near 650 nm, and a narrow band near 800 nm. The filter 51d has a thickness of about 400 nm as shown in FIG.
Through a band having a width of about 80 nm centered at. In addition, as shown in FIG.
Transmits m visible band.

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

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

The return light from the observation site due to the illumination light is imaged on the solid-state imaging device 16 by the objective lens system 15, and is photoelectrically converted. A drive pulse from the driver circuit 3 in the video processor 6 is applied to the solid-state imaging device 16 via the signal line 126, and reading and transfer are performed by the drive pulse. The video signal read from the solid-state imaging device 16 is
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 simultaneously read out, converted to analog signals by a D / A converter 37, output as R, G, B color signals, input to an encoder 38, and output from the encoder 38 as an NTSC composite signal. It has become.

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.
By controlling one of the filters 51a to 51e of the band-pass filter turret 51 selectively in the illumination light path, the wavelength of light transmitted through the rotary filter 50 is controlled by the selected filter. The area is further restricted.

When the filter 51a is selected, a narrow band centered at 650 nm is transmitted at the timing when the R transmission filter of the rotary filter 50 is inserted in the illumination light path, and 569 nm at the timing when the G transmission filter is inserted in the illumination light path. The center narrow band is transmitted. These two narrow-band lights are R and G, respectively.
The object is illuminated at the timing shown in FIG. Then, the images in the two wavelength ranges are output as R and G images, respectively.

FIG. 4 shows the oxygen saturation of hemoglobin (SO
Also described as ₂ . ) Shows the change in blood absorbance (scattered reflection spectrum) due to the change in 569 nm. As shown in this figure, 569 nm is a wavelength at which blood absorbance hardly changes due to a change in SO ₂ , and 650 nm is a wavelength _The wavelength at which the change in blood absorbance due to the change in ₂ is small (less than the degree of change near 569 nm). Therefore, it is possible to observe the blood flow rate of the mucous membrane from the difference between the absorbances at the two wavelengths. As can be seen from FIG. 4, 548.5 nm or 586 nm may be used instead of 569 nm as the wavelength at which the absorbance of blood hardly changes due to the change of SO ₂ .

When the filter 51b is selected, the B transmission filter of the rotary filter 50 is set at the timing when the B transmission filter is interposed in the illumination optical path.
A narrow band centered at 5 nm is transmitted, and a band of 900 nm or more is transmitted at the timing when the G transmission filter is interposed in the illumination optical path. The light in these two bands is radiated to the subject at the timings of B and G, respectively, and a subject image by the radiated light is captured by the solid-state imaging device 16. Then, the images in the two wavelength ranges are output as B and G images, respectively.

By the way, ICG (Indocyanine g
reen, indocyanine green) is mixed with 805
It has the maximum absorption at nm and almost no change in absorption at 900 nm or more. Therefore, the ICG is mixed into blood by, for example, intravenous injection, and the 805 nm and 90
The image in the wavelength range of 0 nm or more makes it possible to observe the defect running state under the mucous membrane. In other words, by using infrared light with good tissue transmittance, light can reach the deep part of the tissue, while in the image in the 805 nm wavelength range,
It becomes a shadow in a blood vessel part. Therefore, by taking the difference between the image in the wavelength range of 805 nm and the image in the wavelength range of 900 nm or more, it becomes possible to visualize the running state of the blood vessel with good contrast.

Further, when the filter 51c is selected, the R transmission filter of the rotary filter 50 is set at a timing when the R transmission filter is interposed in the illumination optical path.
A narrow band near 0 nm is transmitted, a narrow band near 580 nm passes when the G transmission filter is interposed in the illumination light path, and a narrow band near 800 nm is transmitted when the B transmission filter is interposed in the illumination light path. To Penetrate. The three narrow-band lights are respectively radiated to the subject at the timings of R, G, and B, and a subject image by the illumination light is captured by the solid-state imaging device 16. Then, the images in the three wavelength ranges are
These are output as R, G, and B images, respectively.

Incidentally, FIG. 5 shows the spectral characteristics of oxy (oxidized) hemoglobin and deoxy (reduced) hemoglobin in order to show the change in the absorbance of blood due to the change of SO ₂ . In the vicinity and around 800 nm,
A region where the absorbance of the blood by a change in SO ₂ is hardly changed, 650 nm near a region where the absorbance of the blood by a change in SO ₂ is changed. Therefore, the change in SO ₂ can be observed by the images in the three wavelength regions.

Further, when the filter 51d is selected, the B transmission filter of the rotation filter 50 is set at the timing when the B transmission filter is interposed in the illumination optical path.
The band near 0 nm is transmitted. The light in this band is applied to the subject at the timing of B, and the solid-state image sensor 16 captures a subject image using the illumination light. Then, an image in this wavelength range is output as a B image.

As shown in FIG. 5, the region near 400 nm is a region where the absorbance of hemoglobin is large. Therefore, the hemoglobin distribution on the mucous membrane surface can be observed with good contrast by the image in the wavelength region near 400 nm.

When the filter 51e is selected, the rotation filter 50
The transmission wavelength region of the B, G transmission filter is limited to visible light only, normal R, G, B plane-sequential light is applied to the subject, and the subject image by this illumination light is captured by the solid-state imaging device 16. You. Therefore, a normal color image in the visible band can be observed.

Further, the wavelength range is limited by each filter of the band-pass filter turret 51, and the image signals assigned to R, G, and B are processed by the signal processing circuit 60 as shown in FIG. ₂ or an image indicating the amount of hemoglobin can be obtained.

The signal processing circuit 60 has three selectors 61a, 61b, 61c of three inputs and one output, and an image signal corresponding to each wavelength is applied to each input of each selector. . Each of the selectors selects and outputs an image signal corresponding to a different wavelength. The output of each selector is an inverse gamma correction circuit.
Since they are input to 62a, 62b, and 62c and have already been subjected to γ correction by the video processor 6, inverse γ correction is performed to restore the original γ correction. Outputs of the inverse γ correction circuit are input to level adjustment circuits 63a, 63b, 63c, respectively. The level of the level adjustment circuit is adjusted by the level adjustment control signal from the level adjustment control signal
The entire level adjustment is performed by one level adjustment circuit 63. Further, for example, since the vertical axis of the diagram showing the change in blood absorbance due to the change in oxygen saturation as shown in FIG. 5 is the log axis, the output of the level adjustment circuit is
Logarithmic conversion is performed by log amplifiers 65a, 65b, and 65c.

Outputs of two log amplifiers 65a and 65b among the three log amplifiers are input to a differential amplifier 66a, and a difference between image signals corresponding to two wavelengths is calculated. Similarly, outputs of the two log amplifiers 65b and 65c are input to a differential amplifier 66b, and a difference between image signals corresponding to two wavelengths of another combination is calculated.

The filter 51c of the bandpass filter turret 51
Region but when it is selected, the differential amplifier 66a, by 66b, an image signal corresponding to the region where the absorbance of the blood by a change in SO ₂ hardly changes, the absorbance of the blood due to the change in the SO ₂ changes Is calculated, and from this difference, it is possible to know how much oxygen is dissolved in the subject, that is, the oxygen saturation.

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 operation at 67, when selecting a filter 51c, the SO ₂ is obtained. When the filters 51a, 51b, and 51d are selected, the output of the differential amplifier 66b is used to observe and measure changes in blood flow, blood vessel running state, and hemoglobin amount, respectively. The output of the divider 67 and the output of the differential amplifier 66b are input to a two-input selector 68, which outputs one of a signal indicating SO ₂ and a signal indicating blood flow, blood vessel running state, and hemoglobin amount. 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.

Although the signal processing circuit 60 shown in FIG. 12 performs the calculation in a hardware manner, the processing may be performed in a software manner (that is, by a microcomputer).

As described above, in this embodiment, by selectively interposing one of the filters 51a to 51e of the band-pass filter turret 51 in the illumination light path, the oxygen saturation of the hemoglobin in the normal image and the blood is reduced. It is possible to switch and observe images indicating changes in degree, blood flow, blood vessel running state, hemoglobin amount, and the like.

FIGS. 13 to 15 relate to a second embodiment of the present invention.
FIG. 13 is a block diagram showing a configuration of the endoscope apparatus, FIG. 14 is an explanatory diagram showing a color filter array, and FIG. 15 is an explanatory diagram showing a transmission wavelength region of each filter of the color filter array.

This embodiment shows an example in which a simultaneous system is used as a color imaging system.

As shown in FIG. 13, the electronic endoscope 101 has an objective lens system 108 at the distal end of the insertion section, and a color filter array 102 is provided on the front surface at the image forming position of the objective lens system 108. The solid-state imaging device 103 is provided.

As shown in FIG. 14, the color filter array 102 is configured by arranging filters that transmit light in respective wavelength regions of green (G), cyan (Cy), and yellow (Ye) in a mosaic pattern. . In addition, as shown in FIG.
A filter that transmits light has a double transmission characteristic that also transmits a wavelength region Cy ′ near 800 nm in the infrared band, and a filter that transmits G transmits light that also transmits a wavelength region G ′ of about 900 nm or more in the infrared band. It has transmission characteristics.

The light source unit 104 built in the video processor 6
Is a lamp that emits broadband light from visible to infrared
The light emitted from this lamp 105 has a lens 105
The light is condensed at 106 and is incident on the incident end of the light guide 107.

In the present embodiment, a band-pass filter turret 51 similar to that of the first embodiment is disposed between the lens 106 and the light guide 107 incidence end. As in the first embodiment, the band-pass filter turret 51 is rotated by a motor 52 whose rotation is controlled by a filter switching device 55, and one of the filters 51a to 51e is selectively inserted into the irradiation optical path. Is to be worn.

The subject illuminated with the illumination light is connected to the imaging surface of the solid-state imaging device 103 by the objective lens 108. At this time, the color is separated into G, Gy, and Ye by the color filter array 102, but the wavelength is limited by the band-pass filter turret 51.

The solid-state imaging device 103 is read out by applying a drive signal from a driver 120. After the output signal of the solid-state imaging device 103 is amplified by the preamplifier 122, it passes through low-pass filters (LPF) 123 and 124 and a band-pass filter (BPF) 125 in the video processor 6.

The LPF123,124, for example 3 MHz, indicates a cutoff characteristic of 0.86MHz, each processing circuit is divided into the luminance signal Y _L of the luminance signal Y _H and the low frequency of the signal passed through each high-frequency 126 and 127 , And γ correction and the like are performed. Luminance signal Y _H of the high-frequency side through the process circuit 126, after the horizontal contour correction by the horizontal correcting circuit 128, a horizontal aperture correction or the like has been performed, are input to the color encoder 129. The luminance signal Y _L of the low-frequency side through a processing circuit 127 is input to the correction circuit 133 is inputted to a matrix circuit 131, the tracking correction is performed.

On the other hand, a color signal component is extracted through a BPF 125 having a pass band of 3.58 ± 0.5 MHz, and the color signal component is input to a 1HDL (1H delay line) 134, an adder 135, and a subtractor 136. Are separated and extracted. In this case, 1 HDL
The output of 134 is processed by a process circuit 127, and the luminance signal Y on the low frequency side, which is further subjected to vertical aperture correction by a vertical correction circuit 137.
_L and a mixer 138, and the mixed output is added to the adder 13
5 and input to the subtractor 136. The color signal B of the adder 135 and the color signal R of the subtractor 136 are respectively
Is inputted to 41,142, is corrected using the luminance signal Y _L of through correction circuit 133 low-frequency side gamma, are input to the demodulators 143 and 144, after being demodulated color signals B and R, the matrix circuit 131 Is input to This matrix circuit 131, the color difference signals R-Y, B-Y are generated, is input to the subsequent color encoder 129, a luminance signal obtained by mixing the luminance signal Y _H and Y _L, the color difference signals R-Y, B- A chroma signal obtained by orthogonally modulating Y with a subcarrier is mixed (and a synchronizing signal not shown is superimposed thereon), and a composite video signal is output from an NTSC output terminal 145. The image of the observation site is displayed in color by the video signal output from the output terminal 145.

The driver 120 receives a synchronization signal from the synchronization signal generation circuit 152 and outputs a drive signal synchronized with the synchronization signal. The synchronization signal generation circuit 152 is input to a pulse generator 153, and the pulse generator 153 outputs various timing pulses.

In the present invention, as in the first embodiment, by selectively interposing one of the filters 51a to 51e of the band-pass filter turret 51 in the illumination optical path, a passed image,
In addition, it becomes possible to switch and observe images indicating changes in oxygen saturation of hemoglobin in blood, blood flow, blood vessel running state, hemoglobin amount, and the like.

Other configurations, operations and effects are the same as those of the first embodiment.

FIGS. 16 to 20 relate to a third embodiment of the present invention.
FIG. 16 is an explanatory view showing the transmission wavelength range of each filter of the rotary filter, FIG. 17 is an explanatory view showing the transmission wavelength range of one filter of the band-pass filter turret, FIG. 18 is a rotary filter and the filter of FIG. 19 is an explanatory diagram showing a wavelength region of light transmitted through the filter, FIG. 19 is an explanatory diagram showing a transmission wavelength region of another filter of the band-pass filter turret, and FIG. FIG. 3 is an explanatory diagram illustrating a wavelength region of light.

In the present embodiment, the characteristics of each filter of the rotary filter 50,
The configuration is the same as that of the first embodiment except that the characteristics of the bandpass filter in the bandpass filter turret 51 are different.

The transmission characteristics of each of the R, G, B color separation filters provided in the rotary filter 50 are set as shown in FIG.
That is, in the visible light range, the light is separated into R, G, and B, and B
The transmission filter has a double transmission characteristic of transmitting an infrared light range B 'of about 790 nm or more.

On the other hand, as shown in FIG. 17, the band-pass filter turret 51 has an infrared cut filter having an infrared cut characteristic of blocking light in a wavelength region of about 750 nm or more, and as shown in FIG. And a filter having a bandpass characteristic for transmitting light in a wavelength range of 570 to 820 nm.

In this embodiment, the transmission wavelength of the light that has passed through the rotary filter 50 and has been color-separated in a time series is limited by a filter for limiting each wavelength region provided in the band-pass filter turret 51.

That is, when an infrared cut filter having the characteristics shown in FIG. 17 is interposed in the illumination light path, the light reaching the light guide 14 divides the visible light region into R, G, and B light as shown in FIG.
Characteristic. Then, with this illumination light, a normal color image in the visible light region can be observed.

On the other hand, if a band-pass filter having the characteristics shown in FIG. 19 is interposed in the illumination light path,
As shown in Fig. 20, a narrow band centered at about 580 nm and an
The light is split in time series into two narrow-band wavelengths centered on 00 nm.

As shown in FIG. 20, one of the split lights 800n
As shown in FIG. 5, the wavelength region centered on m has a characteristic that its absorbance hardly changes due to the change in oxygen saturation of hemoglobin, and an image in this wavelength region is obtained as a B image. The wavelength range centered at 580 nm is the fifth.
As shown in the figure, hemoglobin has a large absorbance, and an image in this wavelength range is obtained as a G image. Therefore, by processing the images in the two wavelength ranges by the signal processing circuit 60 shown in FIG. 12, a hemoglobin distribution image of the mucous membrane can be obtained. In addition, it is possible to switch between a hemoglobin distribution image of the mucous membrane and a normal color image.

 Other functions and effects are the same as those of the first embodiment.

FIGS. 21 to 26 relate to a fourth embodiment of the present invention.
FIG. 21 is an explanatory view showing the transmission wavelength range of each filter of the rotary filter, FIG. 22 is an explanatory view showing the transmission wavelength range of one filter of the band-pass filter turret, and FIG. 23 is a rotary filter and the filter of FIG. FIG. 24 is an explanatory view showing a wavelength range of light transmitted through the filter, FIG. 24 is an explanatory view showing a transmission wavelength range of one filter of the band-pass filter turret, and FIG. FIG. 26 is an explanatory diagram showing a wavelength region, and FIG. 26 is an explanatory diagram showing the transmission characteristics of hemoglobin to which ICG has been added.

In the present embodiment, the characteristics of each filter of the rotary filter 50,
The configuration is the same as that of the first embodiment except that the characteristics of the bandpass filter in the bandpass filter turret 51 are different.

The transmission characteristics of the R, G, and B color separation filters provided in the circuit filter 50 are set as shown in FIG.
That is, in the visible light range, the light is separated into R, G, and B, and B
The transmission filter has a double transmission characteristic of transmitting an infrared light range B 'of about 900 nm or more. The R transmission filter is
The longer wavelength side is designed to transmit up to about 820 nm.

On the other hand, as shown in FIG. 22, the band-pass filter turret 51 has an infrared cut filter having an infrared cut characteristic of blocking light in a wavelength region of about 700 nm or more, and as shown in FIG. A wavelength limiting filter that transmits light in a wavelength region of 790 nm or more is provided.

In this embodiment, the transmission wavelength of the light that has passed through the rotary filter 50 and has been color-separated in a time series is limited by a filter for limiting each wavelength region provided in the band-pass filter turret 51.

That is, if an infrared cut filter having the characteristics shown in FIG. 22 is interposed in the illumination light path, the light reaching the light guide 14 will be divided into R, G, and B, which divide the visible light region into three, as shown in FIG.
Characteristic. Then, with this illumination light, a normal color image in the visible light region can be observed.

On the other hand, if a band-limiting filter having the characteristics shown in FIG. 24 is interposed in the illumination light path,
As shown in the figure, a narrow band around
The light is split in time series into light in two wavelength ranges of nm or more.

An image in a wavelength range centered at about 800 nm is an R image, and an image in a wavelength range of about 900 nm or more is B ′,
That is, it is visualized as a B image.

Here, it is known that when ICG (indocyanine green) is added to hemoglobin, which is the main pigment of blood in a living body, it has a maximum absorbance peak at 805 nm.
The characteristics of the transmittance are as shown in FIG.

Therefore, by inserting a wavelength limiting filter having the characteristics shown in FIG. 24 into the illumination light path, the maximum peak wavelength range of absorbance when ICG is mixed into a living body by, for example, intravenous injection,
It is possible to obtain an image in a wavelength range where there is substantially no change in light collection.

As described above, according to the present embodiment, the difference between two images obtained by inserting the wavelength limiting filter having the characteristics shown in FIG. 24 into the illumination optical path can be obtained by using the signal processing circuit 60 shown in FIG. 12, for example. Detection enables high-contrast extraction of images of blood vessels on the mucous membrane and under the mucosa that are difficult to observe with visible light, and enables detection of submucosal cancer that is difficult to detect under the mucosa This has the effect of dramatically improving observation performance.

 Other functions and effects are the same as those of the first embodiment.

In the first, third and fourth embodiments, the rotary filter
The positions of the 50 and the band-pass filter turret 51 on the optical path may be reversed.

27 to 29 relate to a fifth embodiment of the present invention.
FIG. 27 is an explanatory diagram showing the transmission wavelength region of each filter of the color filter array, and FIG.
Explanatory diagram showing the wavelength range of light transmitted through the filter of FIG. 17,
FIG. 29 is an explanatory diagram showing a wavelength region of light transmitted through the color filter array and the filter of FIG.

This embodiment has the same configuration as the second embodiment except that the characteristics of each filter of the color filter array 102 and the characteristics of the bandpass filter in the bandpass filter turret 51 are different.

The transmission characteristics of the color filter array 102 are set as shown in FIG. That is, in the visible light range, the color is separated into Cy, G, and Ye, and the Cy transmission filter is
It has a double transmission characteristic that allows transmission of an infrared light region Cy 'of about 790 nm or more. The arrangement of the color filter array 102 is, for example, as shown in FIG.

On the other hand, as shown in FIG. 17, the band-pass filter turret 51 has an infrared cut filter having an infrared cut characteristic of blocking light in a wavelength region of about 750 nm or more, and as shown in FIG. And a filter having a bandpass characteristic for transmitting light in a wavelength range of 570 to 820 nm.

In the present embodiment, in the case of normal observation, an infrared cut filter having the characteristics shown in FIG. 17 is provided in the illumination optical path by the filter switching device 55. Then, the transmission wavelength region of the color filter array 102 is limited by this filter,
As shown in FIG. 28, the color is separated into Cy, G, and Ye. Then, by the same operation as in the second embodiment, a video signal is output, and a normal color image in the visible light region can be observed.

On the other hand, when a band-pass filter having the characteristics shown in FIG. 19 is interposed in the illumination light path, as shown in FIG. 29, two narrow bands having a center at about 580 nm and a narrow band at about 800 nm are provided. It is color-separated into wavelengths in the band. Then, since the same signal processing as that of the second embodiment is performed, the image in the wavelength region centered at 580 nm, which passes through the Cy and G filters, is visualized as a G image, and Cy ′, which is a Cy double transmission region. Is transmitted only through the Cy transmission filter, so that an image in this wavelength range is visualized as a B image.

As described above, according to the present embodiment, by using the signal processing circuit 60 shown in FIG. 12 to process images in the two wavelength ranges shown in FIG. 29, the same effect as in the third embodiment can be obtained. It can be obtained in a simultaneous manner.

 Other functions and effects are the same as those of the second embodiment.

FIGS. 30 and 31 relate to the sixth embodiment of the present invention.
The figure is an explanatory view showing the transmission wavelength region of each filter of the color filter array, and FIG.
It is explanatory drawing which shows the wavelength range of the light which transmitted the filter of the figure.

This embodiment has the same configuration as the second embodiment except that the characteristics of each filter of the color filter array 102 and the characteristics of the bandpass filter in the bandpass filter turret 51 are different.

The transmission characteristics of the color filter array 102 are set as shown in FIG. That is, in the visible light range, the color is separated into Cy, G, and Ye, and the Cy transmission filter is
It has a double transmission characteristic that also transmits the infrared light region Cy 'of about 900 nm or more.The Ye transmission filter has about 820 nm on the long wavelength side.
It is designed to transmit up to m.

On the other hand, as shown in FIG. 22, the band-pass filter turret 51 includes an infrared cut filter having an infrared cut characteristic for blocking light in a wavelength region of about 700 nm or more,
As shown in the figure, a wavelength limiting filter that transmits light in a wavelength region of about 790 nm or more is provided.

In the present embodiment, in the case of normal observation, as shown in FIG. 28, Cy, as shown in FIG. G, Ye
And a normal color image in the visible light region can be observed.

On the other hand, if a wavelength limiting filter having the characteristics shown in FIG. 24 is interposed in the illumination optical path, as shown in FIG. 31, a narrow band centered at about 800 nm and a wavelength band of about 900 nm or more are obtained. Color separated. Since the light in the wavelength range centered at about 800 nm is received only by the pixels corresponding to the Ye transmission filter, an image in this wavelength range is visualized as an R image, and the wavelength in the wavelength range of about 900 nm or more. Light in the wavelength range of Cy ', which is a double transmissive area of Cy, transmits only through the Cy transmission filter, so that an image in this wavelength range is visualized as a B image.

As described above, according to this embodiment, by using the signal processing circuit 60 shown in FIG. 12 to process images in the two wavelength ranges shown in FIG. 31, the same effect as in the fourth embodiment can be obtained. It can be obtained in a simultaneous manner.

 Other functions and effects are the same as those of the second embodiment.

It should be noted that the present invention is not limited to the above embodiments, and for example,
Bandpass filter turret 51 as wavelength limiting means
The transmission characteristics and the number of each filter can be set arbitrarily.

Further, as the wavelength limiting means, a plurality of filters having different transmission characteristics may be provided in the optical path so as to be insertable and removable. Further, the position where the wavelength limiting means is provided may be anywhere on the illumination optical path or the observation optical path to the imaging means, such as in front of the light guide emission end, in the imaging optical system, in front of the solid-state imaging device, in the middle of the light guide, etc. May be provided.

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, an image in a general visible region and a specific wavelength can be obtained by inserting and removing a wavelength limiting unit on an illumination optical path or an observation optical path leading to an imaging unit. There is an effect that an image based on a region can be selectively obtained.

[Brief description of the drawings]

1 to 12 relate to a first embodiment of the present invention.
FIG. 2 is a block diagram showing the configuration of the endoscope apparatus, FIG. 2 is an explanatory view showing a bandpass filter turret, FIG. 3 is a side view showing the entire endoscope apparatus, and FIGS. 4 and 5 are hemoglobins. FIG. 6 is an explanatory diagram showing a change in the absorbance of blood due to a change in oxygen saturation, FIG. 6 is an explanatory diagram showing a transmission wavelength region of each filter of a rotary filter, and FIGS. 7 to 11 are filters of a bandpass filter turret. FIG. 12 is a block diagram showing a processing circuit for obtaining the amount of hemoglobin and oxygen saturation, and FIGS.
FIG. 13 relates to a second embodiment of the present invention, FIG. 13 is a block diagram showing a configuration of an endoscope apparatus, FIG. 14 is an explanatory view showing a color filter array, and FIG. FIG. 16 to FIG. 20 relate to a third embodiment of the present invention, FIG. 16 is an explanatory diagram showing the transmission wavelength region of each filter of the rotary filter, and FIG. FIG. 18 is an explanatory view showing a transmission wavelength range of one filter of the filter turret, FIG. 18 is an explanatory view showing a wavelength range of light transmitted through the rotating filter and the filter of FIG. 17, and FIG. 19 is another band-pass filter turret. FIG. 20 is an explanatory view showing the transmission wavelength range of one filter, and FIG.
Explanatory diagram showing the wavelength range of light transmitted through the filter of FIG. 19,
FIGS. 21 to 26 relate to a fourth embodiment of the present invention.
The figure is an explanatory view showing the transmission wavelength range of each filter of the rotating filter, FIG. 22 is an explanatory view showing the transmission wavelength range of one filter of the bandpass filter turret, and FIG. 23 is a view showing the rotating filter and the filter of FIG. FIG. 24 is an explanatory view showing a wavelength range of transmitted light, and FIG.
FIG. 25 is an explanatory diagram showing transmission wavelength ranges of two filters, FIG. 25 is an explanatory diagram showing wavelength regions of light transmitted through a rotating filter and the filter of FIG. 24, and FIG. 26 is an explanatory diagram showing transmission characteristics of hemoglobin to which ICG is added. FIGS. 27 to 29 relate to a fifth embodiment of the present invention. FIG. 27 is an explanatory diagram showing the transmission wavelength region of each filter of the color filter array. FIG. 28 is a color filter array and FIG. FIG. 29 is an explanatory diagram showing a wavelength region of light transmitted through the filter of FIG. 29, FIG. 29 is an explanatory diagram showing a wavelength region of light transmitted through the color filter array and the filter of FIG. 19, and FIG. 30 and FIG. According to the sixth embodiment,
FIG. 30 is an explanatory diagram showing the transmission wavelength region of each filter of the color filter array, and FIG.
FIG. 25 is an explanatory diagram showing a wavelength region of light transmitted through the filter of FIG. 24. DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope, 6 ... Video processor 7 ... Monitor, 15 ... Objective lens system 16 ... Solid-state imaging device, 21 ... Lamp 50 ... Rotating filter 51 ... Band pass filter turret

Claims (1)

(57) [Claims] 1. A first color separation means (filter) capable of transmitting light in a first wavelength region for obtaining a color image and a second wavelength region for obtaining blood information, and for obtaining a color image A third wavelength range different from the first wavelength range and a second wavelength range different from the second wavelength range for obtaining blood information.
A color separation unit (filter); an imaging unit configured to form an object image separated into different wavelength regions by the first color separation unit and the second color separation unit on an imaging surface; The wavelength region of the subject image formed on the imaging surface by the color separation unit and the second color separation unit is selectively limited, and the wavelength range of the first color separation unit and the second color separation unit is reduced. A wavelength region limiting unit that forms an image of a subject consisting of a wavelength region for obtaining the blood information on the imaging surface, and a signal separation unit that separates a signal output from the imaging unit into a plurality of different color information signals. Display means for displaying a subject image based on a plurality of different color information signals separated by the signal separation means; and a wave for obtaining the blood information based on the plurality of different color information signals separated by the signal separation means. A blood information calculation unit capable of calculating blood information relating to the subject when the subject image including the region is formed on the imaging surface; and blood information of the subject based on a calculation result of the blood information calculation unit can be displayed. An endoscope device comprising: blood information display means.