JPH10151104A - Fluorescent endoscope device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent endoscope device capable of keeping bright observation environment at the time of observation under fluorescence, and observing an object at large depth during observation under ordinary light. SOLUTION: The light of a lamp 10 is introduced to the light guide buffer 8 of an electronic endoscope 2A through a band-pass limiting rotary filter 11, an RGB rotary filter 13 and the like, and then irradiated to a specimen 19 having a fluorescent material administered. Reflected light and fluorescence thereby generated are received by a CCD 21 via an objective lens 20 and a filter diaphragm 22 or the like laid along the optical path thereof. The filter diaphragm 22 has a characteristic, so that only the center small opening thereof becomes a light transmission zone for visible rays, and both of the opening and a ring type opening at the outside thereof become a light transmission zone for fluorescence. In addition, the image of an object at large depth is available with an incident light quantity reduced during ordinary observation under visible rays, while a bright image is available without much reduction of an incident light quantity during observation under fluorescence.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescence endoscope apparatus capable of observing fluorescence from a site such as an affected part.

[0002]

2. Description of the Related Art In recent years, by inserting an insertion portion into a body cavity, a gastrointestinal tract such as the esophagus, stomach, small intestine, and large intestine, and a trachea such as a lung have been observed. 2. Description of the Related Art An endoscope capable of performing various treatments using a treatment tool is used. In particular, an electronic endoscope using an electronic imaging device such as a charge-coupled device (CCD) is widely used because an image can be displayed on a monitor and an operator who operates the endoscope is less fatigued.

[0003] Recently, a diagnostic method has been attracting attention in which a fluorescent substance is previously administered to the body of a subject to be examined, and a fluorescent image is obtained by irradiating the fluorescent substance with excitation light.
In particular, an apparatus capable of observing both a normal light image obtained by irradiating a subject with white light and a fluorescent image obtained by irradiating excitation light can be expected to improve diagnostic performance.

As such an apparatus, for example, Japanese Patent Application Laid-Open No.
Japanese Patent No. 59783 discloses a device for irradiating light of a wavelength band for exciting a fluorescent substance and a wavelength band of a visible region for normal observation while switching the light with a rotary filter.

[0005]

However, generally, the fluorescence observed at the time of irradiation with excitation light is weak, and is extremely dark compared to the reflected light observed at the time of irradiation with normal observation light.
Both a fluorescent image and a normal image could not be obtained with appropriate brightness.

[0006] Further, since the fluorescent light emitted from the fluorescent substance is weak, the obtained fluorescent image has poor image quality.

In addition, when a fluorescent substance emits infrared fluorescent light having good permeability to a living body, light from outside the body may be mixed into the same wavelength band as the fluorescent light, resulting in noise.

(Object of the Invention) The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a fluorescent endoscope apparatus which is bright during fluorescent observation and can be observed at a deep subject depth during normal light observation. Aim.

[0009]

In a fluorescence endoscope apparatus for diagnosing a subject by administering a fluorescent substance to an object to be inspected, the fluorescent endoscope apparatus includes light in a first wavelength band including an excitation wavelength of the fluorescent substance and visible light. Light source means for irradiating the object to be inspected with light in a second wavelength band; imaging means for imaging a visible light image of the object to be inspected and a fluorescent image of the fluorescent substance; and Aperture means inserted on the optical path with the imaging means, wherein the aperture means transmits light in the wavelength band of fluorescence of the fluorescent substance without transmitting visible light and a visible light transmitting portion that transmits visible light. However, by having a configuration having a visible light non-transmitting portion having a transmission area larger than the visible light transmitting portion, the fluorescent light can pass through the diaphragm means more, the image by the fluorescent light becomes brighter, and the image by the ordinary light is reduced. It can be observed at a deeper depth of field.

[0010]

Embodiments of the present invention will be specifically described below with reference to the drawings. (First Embodiment) FIGS. 1 to 11 relate to a first embodiment of the present invention, and FIG. 1 is a block diagram showing the overall configuration of a fluorescence endoscope apparatus according to the first embodiment. FIG. 2, FIG. 2 is an explanatory diagram showing the configuration of the band-limited rotary filter, FIG. 3 is an explanatory diagram showing the spectral transmission characteristics of the band-limited rotary filter, and FIG.
FIG. 3 is an explanatory diagram illustrating a configuration of a GB rotation filter. FIG. 5 is an explanatory diagram showing the spectral transmission characteristics of the RGB rotation filter, FIG. 6 is an explanatory diagram showing the spectral transmission characteristics of the excitation light cut filter, FIG. 7 is an explanatory diagram showing the configuration of the filter aperture, and FIG. FIG. 9 is an explanatory diagram showing the operation during normal light observation, FIG. 10 is an explanatory diagram showing the operation during fluorescence observation, and FIG. 11 is an explanatory diagram showing the operation during normal light / fluorescent simultaneous observation. It is. An object of the present embodiment is to provide a fluorescent endoscope apparatus which can observe an image by fluorescent light more brightly and an image by ordinary light at a deeper depth of field.

A fluorescent endoscope apparatus 1A according to a first embodiment of the present invention shown in FIG. 1 includes an electronic endoscope 2A for insertion into a body cavity for observation and a light and excitation light for normal observation. A light source device 3A that emits light, a processor 4A that performs signal processing,
Monitor 5 that displays an image using normal light and an image using fluorescent light
And a laser light source 6 for performing treatment by laser light.

The electronic endoscope 2A has an elongated insertion portion 7 to be inserted into a body cavity, and a distal end portion 17 of the insertion portion 7 has a built-in imaging means. A light guide fiber 8 for transmitting illuminating light and excitation light for normal observation is inserted into the insertion portion 7, and a light incident side of the light guide fiber 8 at the hand side is detachably connected to the light source device 3 </ b> A. Can be.

The light source device 3A includes a lamp 10 that emits light including an infrared wavelength band to a visible light band, and the lamp 10
, An illumination light aperture 12 for limiting the light amount from a lamp 10, an RGB rotation filter 13, and a condenser lens 14 for condensing light. The band limiting filter 11 and the RGB rotation filter 13 are motors 15 and 16 respectively.
Is driven to rotate.

As shown in FIG. 2, the band limiting filter 11 includes a visible light transmitting filter 11a and an infrared light transmitting filter 11a.
b. FIG. 3 shows the transmission characteristics of the visible light transmission filter 11a and the transmission characteristics of the infrared light transmission filter 11b.

The light of the lamp 10 is extracted by the visible light transmitting filter 11a or the infrared light transmitting filter 11b, and only the light component in the visible light band or the infrared band is extracted. Filter 1
3 is incident.

As shown in FIG. 4, the RGB rotation filter 13 has R, G, B transmission filters 13a, 13a in the circumferential direction.
b and 13c are provided so as to be divided into three equal parts.
Are sequentially inserted into the optical path by being rotationally driven.

The R, G, B transmission filters 13a, 1
FIG. 5 shows the transmission characteristics of 3b and 13c. R filter 13
The spectral transmission characteristics of a, G filter 13b, and B filter 13c are such that, in addition to light in the red, green, and blue wavelength regions, light having a wavelength that excites an indocyanine green (ICG) derivative-labeled antibody is also transmitted. ing.

The light that has passed through the RGB rotation filter 13 is condensed by a condenser lens 14 and radiated to the incident end of the light guide fiber 8. Then, light is transmitted by the light guide fiber 8, and the distal end 1 of the insertion section 7 is transmitted.
The light exits from the distal end surface fixed to 7 and further passes through the illumination lens 18 attached to the illumination window to the object to be inspected (or the object to be inspected) 19 in the body cavity.

If an ICG derivative-labeled antibody is previously administered as a fluorescent substance having an affinity for a lesion such as cancer in the body of the subject 19, it is excited by irradiation with infrared light near 770 to 780 nm. Then, fluorescence in the infrared region around 810 to 820 nm is generated.

An observation window is provided at the tip portion 17 adjacent to the illumination window, and an objective lens 20 is attached to the observation window to collect reflected light and fluorescent light from the illuminated inspection object 19. The light forms an image at the image forming position. At this image forming position, a CCD 21 is arranged as a solid-state image sensor,
Perform photoelectric conversion. The objective lens 20 and the CCD 21 constitute an imaging unit.

In this embodiment, the objective lens 20 and the CCD
As an aperture means for limiting the amount of incident light on the imaging optical path between the filter aperture 21 and a filter aperture 21, a filter aperture 22 having a transmission characteristic having wavelength dependence is arranged, and an excitation light cut filter 23 for cutting the excitation light is also arranged.

The filter diaphragm 22 is concentrically divided into three parts as shown in FIG. That is, a circular visible light transmitting portion 22a formed on the innermost side, a ring-shaped visible light non-transmitting portion 22b formed on the outer side,
A ring-shaped light-shielding portion 22c formed on the outside is provided.

FIG. 7 shows transmission characteristics of the visible light transmitting portion 22a, the visible light non-transmitting portion 22b, and the light shielding portion 22c.

The visible light transmitting portion 22a of the innermost small circular region has a substantially flat transmission characteristic from the visible light band to the infrared band, and the visible light non-transmitting portion 22b does not transmit the visible light region, Light in the wavelength band of the external fluorescence has a filter characteristic of transmitting. Accordingly, the filter diaphragm 22 functions as a diaphragm having a small aperture since only the visible light transmitting portion 22a having a small transmission cross-sectional area or a small transmission region transmits light with respect to visible light. In this case, both the visible light transmitting portion 22a and the visible light non-transmitting portion 22b transmit light, and thus serve as a stop having a large aperture. The outermost light shielding portion 22c shields light in all wavelength bands of visible light and infrared light.

The image signal photoelectrically converted by the CCD 21 is a preamplifier 24 for amplifying the signal in the processor 4A, and an automatic gain control (AG) for automatically adjusting the gain.
C) a circuit 25, an A / D conversion circuit 26, a multiplexer circuit 27 for switching, a first frame memory 28 and a second frame memory 29 for temporarily storing an image, an image processing circuit 30 for performing processing such as image enhancement, The image is output to the monitor 5 via an image display control circuit 31 for controlling image display and a D / A conversion circuit 32.

The processor 4A includes a preamplifier 2
An automatic dimming circuit 33 that controls the opening amount of the illumination light diaphragm 12 based on the signal passed through 4 and a timing control circuit 34 that synchronizes the entire fluorescence endoscope apparatus 1A are provided.

A laser guide 37 for guiding laser light is connected to the laser light source 6 for generating laser light for laser treatment, and this laser guide 37 can be inserted into a forceps channel 36 provided in the electronic endoscope 2A. It has a structure.

An observation mode selection switch is provided on the front panel or the like of the processor 4A. The observation mode selection switch allows a normal observation mode for observing a normal endoscope image using visible light, and a fluorescence image using fluorescence. It is possible to select a fluorescence observation mode for observation, a fluorescence and a fluorescence / normal observation mode for observing with a normal endoscope image.

That is, when the selection is made by the observation mode selection switch, the instruction is input to the timing control circuit 34, and the timing control circuit 34
The switching control of the multiplexer 27 is performed, and the control corresponding to each mode shown in FIGS. 9 to 11 is performed.

For example, when the normal observation mode is selected, the timing control circuit 34
The rotation amount of the motor 15 is controlled so that one visible light transmission filter 11a is fixed on the optical path, and the rotation control of the motor 16 is performed so that the RGB rotation filter 13 rotates 30 times per second.

The lighting in this state, that is, R, G,
The image signal obtained by the imaging by the CCD 21 under the sequential illumination of B is converted into the first signal by controlling the switching of the multiplexer 27.
Is stored in the frame memory 28 or the second frame memory 29.

When the fluorescent observation mode is selected, the timing control circuit 34
The rotation amount of the motor 15 is controlled so that one infrared light transmission filter 11b is fixed on the optical path, and the rotation control of the motor 16 is performed such that the RGB rotation filter 13 rotates 30 times per second.

The illumination in this state, that is, the fluorescence image signal obtained by the imaging by the CCD 21 under the irradiation of the infrared light is controlled by switching the multiplexer 27 to the first frame memory 28 or the second frame memory 28. Is stored in the frame memory 29.

Further, when the fluorescence / normal observation mode is selected, the timing control circuit 34 controls the rotation of the motor 15 so that the band-limited rotation filter 11 rotates 90 times per second, and the RGB rotation filter 13 rotates 30 times per second. The rotation of the motor 16 is controlled so that

The illumination under this condition, that is, under the sequential irradiation of R, infrared light, G, infrared light, B and infrared light, the CCD
Red, fluorescent, green, fluorescent, blue,
The switching of the multiplexer 27 for the fluorescent light image signal is controlled so that the visible light image signal is stored in the first frame memory 28 and the fluorescent light image signal is stored in the second frame memory 29.

In the present embodiment, an aperture means formed by a filter aperture 22 for limiting the amount of incident light is provided on the optical path of the imaging means, and this filter aperture 22 has only a small circular portion at the center with respect to visible light. Is an aperture through which
On the other hand, with respect to the fluorescent light, the visible light transmitting portion 22a and the visible light non-transmitting portion 22b are arranged such that the small circular portion in the center and the ring-shaped opening outside the opening form an opening through which the fluorescent light can pass.
To significantly reduce the amount of incident light for visible light and obtain an image with a deep depth of field. It is characterized by being obtained.

Next, the operation of the thus-configured fluorescence endoscope apparatus 1A will be described. For example, an ICG derivative-labeled antibody is administered into the body of the subject 19 as a fluorescent substance that has an affinity for a lesion such as cancer, excites with light in the infrared region, and emits fluorescence in the infrared region.

In the case of this ICG derivative-labeled antibody, 77
Excited by irradiation of infrared light near 0 to 780 nm,
It emits infrared fluorescence near 820 nm. Therefore, when the body is irradiated with excitation light, a large amount of fluorescence is emitted from the lesion,
By detecting this fluorescence, the presence or absence of a lesion can be confirmed.

The lamp 10 of the light source device 3A is a xenon lamp, and emits light in a visible light region and a wavelength band including the excitation wavelength of the ICG derivative-labeled antibody. Light emitted from the lamp 10 is incident on the band-limiting rotary filter 11.

As shown in FIG. 2, the band-limited rotary filter 11 is formed by dividing a circular filter plate into two, and a half area is a visible light transmitting filter 11a and the other half is an infrared light transmitting filter 11b. Area.

The visible light transmitting filter 11a is a bandpass filter that transmits a visible light region including red, green, and blue as shown by the spectral transmission characteristics indicated by the solid line in FIG. The infrared light transmission filter 11b is a bandpass filter that transmits only the wavelength band that excites the ICG-labeled antibody and blocks light such as the wavelength band of fluorescence, as indicated by the dotted line.

The light passing through the band-limiting rotary filter 11 is adjusted in light quantity by an illumination light stop 12 and is incident on an RGB rotary filter 13.

As shown in FIG. 4, the R, G, and B rotary filters 13 are arranged so as to divide the filter plate into three equal parts.
a, a G filter 13b, and a B filter 13c. As shown in FIG. 5, the spectral transmission characteristics of each filter transmit not only light in the red, green, and blue wavelength regions but also light having a wavelength that excites the ICG derivative-labeled antibody.

At the time of normal light observation, the visible light transmitting filter 11a of the band limiting rotary filter 11 is fixed on the optical path,
The RGB rotation filter 13 rotates 30 times per second, so that red, green, and blue lights are sequentially emitted (see FIG. 9).

At the time of fluorescence observation, the band limiting rotation filter 11
Of the infrared light transmitting filter 11b is fixed on the optical path,
The B rotation filter 13 rotates 30 times per second, so that infrared light in the wavelength band of the excitation light is emitted (see FIG. 10).

When simultaneously observing the fluorescence image and the normal light image, the RGB rotation filter 13 rotates 30 times per second and the band-limited rotation filter 11 rotates 90 times per second, so that the red, excitation light, green, excitation Light, blue, and excitation light are sequentially applied (see FIG. 11).

At this time, the timing control circuit 34
The B rotation filter 13 and the band limited rotation filter 11 are controlled to rotate in synchronization.

The light transmitted through the RGB rotary filter 13 is incident on the light guide fiber 8 of the electronic endoscope 2A, and is transmitted by the light guide fiber 8. Then, the object to be inspected 19 is irradiated from the distal end surface of the light guide fiber 8. Electronic endoscope 2A and light source device 3
All of the optical systems of A are designed for the infrared region. In the subject 19, the irradiation light is absorbed by the living tissue,
While being reflected, the lesion emits fluorescence due to the administered fluorescent substance.

The reflected light and the fluorescent light from the test object 19 are imaged by the CCD 21 via the filter stop 22 and the excitation light cut filter 23 arranged on the optical path. Filter aperture 2
As shown in FIG. 6, reference numeral 2 includes a visible light transmitting portion 22a, a visible light non-transmitting portion 22b, and a light shielding portion 22c concentrically from the center, and the respective spectral transmission characteristics are as shown in FIG. .

The visible light non-transmitting portion 22b does not transmit visible light, but transmits light in the infrared fluorescent wavelength band. Therefore, the filter diaphragm 22 is a visible light transmitting portion 22 for visible light.
Since only a transmits light, the aperture serves as a small aperture. For infrared fluorescent light, both the visible light transmitting portion 22a and the non-visible light transmitting portion 22b transmit light, so the large aperture is used. Will play a role.

For normal light (visible light) observation, a deep and sharp visible light image is formed on the CCD 21 at the time of normal light (visible light) observation.
1 is formed. At the time of normal light observation using visible light,
It is necessary to obtain a sharp image because the lesion is identified from the color and shape of the living tissue.However, fluorescence observation is a presence diagnosis and only the presence or absence of the lesion can be obtained as the brightness of the image. It is necessary to obtain a brighter image than to obtain a proper image, and this embodiment satisfies this.

The excitation light cut filter 23 is configured to block the excitation light component of the ICG derivative-labeled antibody and transmit the fluorescence component and the visible light component, and the spectral transmission characteristics are as shown in FIG. I have.

Therefore, in the CCD 21, according to the positions of the RGB rotation filter 13 and the band-limited rotation filter 11,
Receives red, green, blue visible light or infrared fluorescent light.
The CCD 21 is driven by a CCD drive circuit (not shown) to
The B rotation filter 13 is driven in synchronization with the rotation of the band limiting filter 11, and forms an image of 180 frames per second or 90 frames per second depending on the presence or absence of rotation of the band limiting rotation filter 11 (see FIGS. 9 to 11). .

The electric signal from the CCD 21 is input to the preamplifier 24 of the processor 4A, amplified,
The gain is adjusted by the C circuit 25. Thereafter, the signal is input to the A / D conversion circuit 26, and is converted from an analog signal to a digital signal. This digital signal is stored in the first frame memory 28 or the second frame memory 29 via the multiplexer 27.

Based on the control signal from the timing control circuit 34, the multiplexer 27 stores a signal captured when the visible light transmission filter 11a of the band-limiting rotation filter 11 is inserted in the first frame memory 28, The signal picked up when the external light transmission filter 11b is inserted is switched to the second frame memory 29 to be input.

First and second frame memories 28 and 29
Are composed of three frame memories (not shown), respectively.
3a, G filter 13b, B filter 13
Each image when c is inserted is recorded.

The three frame memories are read out at the same time, so that the frame sequential images sent in time series are synchronized. First and second frame memories 28 and 29
Is input to an image processing circuit 30, where image processing such as image enhancement and noise removal is performed, and further input to an image display control circuit 31 for simultaneous display of a fluorescent image, a normal image, and character information. Is performed.

The digital signal output from the image display control circuit 31 is input to the D / A conversion circuit 32, converted into an analog signal, and output to the monitor 5. The automatic light control circuit 33 sends a signal for controlling the illumination light diaphragm 12 so that illumination light of appropriate brightness is obtained. The timing control circuit 34 synchronizes the rotation of the RGB rotation filter 13 and the band limiting filter 11, the driving of the CCD, and the processing of various video signals. On the monitor 5, the normal light image, the fluorescent image, or both of them can be simultaneously observed according to the position of the band-limiting rotary filter 11.

In this case, the normal light image displayed on the display surface of the monitor 5 becomes a sharp image having a large depth of field, while the fluorescent image becomes a bright image, which is useful for accurate diagnosis.

Further, in this embodiment, since the normal light image and the fluorescent image can be taken simultaneously, the positioning and the like can be easily performed when the normal light image is used to further confirm the possibility of a lesion obtained by the fluorescent image. There are advantages such as being able to do.

When performing laser treatment, the laser light source 6
Emits a laser beam. The emitted laser light is applied to the affected part through the laser guide 37. The laser light source 6 uses a semiconductor laser, and the wavelength is adjusted to the excitation wavelength of the ICG derivative-labeled antibody.

Therefore, the fluorescence image and the ordinary light image are not largely disturbed by the laser light irradiation. Further, when the laser light is I
The affected part can be efficiently treated because it is absorbed by the CG derivative-labeled antibody.

In this embodiment, a single lamp is used as the light source for observation. However, two or more light sources such as a halogen lamp for normal light observation and a laser or light emitting diode for exciting a fluorescent substance are used. They may be combined.

The illumination light for exciting the fluorescent substance may be irradiated from outside the body. The function of cutting the excitation light is not limited to the function provided on the front surface of the CCD 21, but may be provided on the surface of the objective lens 20 or the surface of the filter diaphragm 22.

The position of the CCD 21 is determined by the electronic endoscope 2A.
The light is not limited to the one disposed at the distal end portion 17 of the insertion portion 7, but may be provided inside the processor 4 </ b> A to guide the light with the image guide fiber, or disposed inside the camera head detachable from the optical endoscope. May be.

Further, an image intensifier may be arranged on the front surface of the CCD 21 to improve the sensitivity. Further, instead of processing for each frame, processing may be performed for each field.

This embodiment has the following effects. Since the area through which the fluorescent light is transmitted in the aperture is made larger than the area through which the visible light (normal light) transmits, a large amount of fluorescent light can pass through the aperture, the image with the fluorescent light is brighter, and the image with the normal light is brighter. Observation can be performed at a deeper depth of field.

(Second Embodiment) Next, a second embodiment of the present invention will be described.

FIGS. 12 to 17 relate to a second embodiment of the present invention. FIG. 12 is a block diagram showing the overall configuration of an endoscope apparatus, and FIG. 13 is a diagram showing the configuration of a parallel rotation filter. FIG. 14, FIG. 14 is an explanatory diagram showing the spectral transmission characteristics of the parallel rotation filter, FIG. 15 is an explanatory diagram showing the configuration of the liquid crystal aperture, FIG. 16 is an explanatory diagram showing the configuration of the integration processing circuit, and FIG.
It is explanatory drawing which shows operation | movement of embodiment.

An object of the present embodiment is to provide a fluorescent endoscope apparatus which can observe a brighter image with less noise with fluorescent light and can observe an image with a deeper subject and less blur with normal light. is there. The second embodiment has a configuration similar to that of the first embodiment. Therefore, the following description will focus on the differences, and configurations having similar functions will be assigned the same reference numerals and descriptions thereof will be omitted.

A fluorescence endoscope apparatus 1B of the second embodiment shown in FIG. 12 is different from the fluorescence endoscope apparatus 1A of FIG. 1 in that a liquid crystal is used instead of the filter diaphragm 22 in the electronic endoscope 2A. The band-limiting filter 11 is removed from the electronic endoscope 2B employing the aperture 38 and the light source device 3A.
A light source device 3B using a parallel rotation filter 39 for limiting the transmission wavelength in place of the GB rotation filter 13, and R memories 41a and G for the first frame memory 28 and the second frame memory 29 in the processor 4A. The processor 4B provided with the memories 41b and 41c for B and the three accumulation processing circuits 42 is used.

The parallel rotation filter 3 in the light source device 3B
The motor 9 is driven to rotate by a motor 40, and the motor 40 is controlled by a timing control circuit 34 so that the rotation speed is constant. As shown in FIG. 13, R, G, B filters 39a, 39
b, 39c, and three IR filters 39d are separately provided on the inner peripheral side. The parallel rotation filter 39 is movable in the direction orthogonal to the rotation axis (vertical direction in FIG. 12), and the outer R, G, B filters 39a, 39b, 39c are interposed in the optical path during normal observation, and the fluorescent light is emitted. During observation, an inner IR filter 39d is interposed.

The R, G, B filters 39a, 39
b, 39c and the transmission characteristics of the IR filter 39d are shown in FIG.
Shown in The R, G, and B filters 39a, 39b, and 39c transmit red, green, and blue wavelength components, respectively, and the IR filter 39d transmits the excitation light component of the ICG derivative-labeled antibody.

A liquid crystal diaphragm 38, which is disposed in the optical path between the objective lens 20 and the CCD 21 in the electronic endoscope 2B and limits the amount of light passing through, is concentrically arranged as shown in FIG.
It is divided into two parts.

In other words, as shown in FIG. 15, the liquid crystal panel 38 is concentrically formed of an opening 38a, a liquid crystal plate 38b, and a light-shielding portion 38c from the center. The voltage applied to the liquid crystal plate 38b is controlled by the timing control circuit 34.

The liquid crystal plate 38b has such a property that it does not transmit light when a voltage is applied, and transmits light when no voltage is applied. Therefore, when a voltage is applied, the aperture becomes small, the depth of the subject is deep, and a sharp image is formed on the CCD 21.
Formed on top. When no voltage is applied, the aperture is large, and a bright image is formed on the CCD 21.

The processor 4B has a preamplifier 24, an AGC circuit 25, an A / D conversion circuit 26, and a multiplexer circuit 27, as in FIG.
The signal selected in the above is the R memory R41a and the G memory G
41b, and input to the B memory B41c.

The R memory R41a and the G memory G
Output signals of the memory 41b and the memory B for B 41c are input to the image processing circuit 30 via the integration processing circuit 42, and the output of the image processing circuit 30 is output to the image display control circuit 31, the D / A conversion circuit 32 as in FIG. Is output to the monitor 5 via

The processor 4B synchronizes the automatic light control circuit 33 and the entire fluorescence endoscope apparatus 1B, rotates the parallel rotation filter 39, and controls the liquid crystal diaphragm 38 and the integration processing circuit 42.
Is provided with a timing control circuit 34 for controlling the timing.

As shown in FIG. 16, the integration processing circuit 42 includes two multipliers 43 and 46 whose coefficients can be rewritten.
And an adder 44 and a frame memory 45. Further, a laser light source 6 for generating laser light for laser treatment and a laser guide 37 for guiding the laser light are provided.

Next, the operation of the thus-configured fluorescence endoscope apparatus 1B will be described. A fluorescent substance having an affinity for a focus such as cancer, such as an indocyanine green (ICG) derivative-labeled antibody, has been administered to the body of the subject 19 in advance.

The lamp 10 of the light source device 3B emits light in the visible light region and in a wavelength band including the excitation wavelength of the ICG derivative-labeled antibody. The amount of light emitted from the lamp 10 is adjusted by the illumination light stop 12 and passes through the parallel rotation filter 39.

The light transmitted through the parallel rotation filter 39 is made incident on the incident end of the light guide fiber 8 of the electronic endoscope 2B. As shown in FIG. 13, the parallel rotation filter 39 includes an R filter 39a, a G filter 39b, and a B filter 39 that transmit red, green, and blue lights in the visible light region on the outer periphery.
c is disposed, and an IR filter 39d that transmits light in the infrared region is disposed on the inner periphery.

The transmission characteristics of each filter are shown in FIG.
The IR filter 39d is an IC filter
Transmits the excitation light component of the G derivative-labeled antibody. The parallel rotation filter 39 rotates at 30 rotations per second during operation. The parallel rotation filter 39 is installed so as to be movable in the direction perpendicular to the rotation axis. During normal light observation, the R, G, B filters 39a, 39b, 39c on the outer periphery are inserted into the illumination optical path, so that the red rotation filter 39 becomes red. , Green, and blue light are sequentially radiated to the subject, and the inner peripheral IR filter 39 is used during fluorescence observation.
By inserting d into the illumination light path, infrared light in the wavelength band of the excitation light is emitted.

The reflected light and fluorescent light from the test object 19 pass through the liquid crystal diaphragm 38 and the excitation light cut filter 23,
Is imaged. As shown in FIG. 15, the liquid crystal diaphragm 38 includes an opening 38a, a liquid crystal plate 38b, and a light shielding portion 38c concentrically from the center, and the voltage applied to the liquid crystal plate 38b is controlled by the timing control circuit 34. Liquid crystal panel 3
8b has the property that it does not transmit light when a voltage is applied and transmits light when no voltage is applied.

As shown in FIG. 17, at the time of normal observation, a voltage is applied, the aperture becomes smaller, and a sharp image with a deeper depth of field is formed on the CCD 21. Also,
At the time of fluorescence observation, the stop becomes large in the state where no voltage is applied, and a bright image is formed on the CCD 21.

The excitation light cut filter 23 is configured to block the excitation light component of the ICG derivative-labeled antibody and transmit the fluorescence component and the visible light component, and the spectral transmission characteristics thereof are as shown in FIG. I have.

Therefore, the CCD 21 receives red, green, blue visible light or infrared fluorescent light according to the position of the parallel rotation filter 39. The CCD 21 is a C (not shown)
Driven in synchronism with the rotation of the parallel rotation filter 39 by the CD drive circuit, 90 frames per second during normal light observation,
At the time of fluorescence observation, an image of 30 frames is formed every second (see FIG. 17). In addition, the exposure time of the CCD 21 is made longer (three times in FIG. 17) during fluorescence observation than during normal light observation so that a brighter image can be obtained.

The electric signal from the CCD 21 is input to the preamplifier 24 of the processor 4B, amplified,
The gain is adjusted by the C circuit 25. Thereafter, the signal is input to the A / D conversion circuit 26, and is converted from an analog signal to a digital signal. The digital signal is stored in the three frame memories, the R memory R41a, the G memory G41b, and the B memory B41c via the multiplexer 27.

The multiplexer 27 controls the parallel rotation filter 39 based on the control signal from the timing control circuit 34.
When the R filter 39a is inserted into the R memory R41a,
When G filter 39b or IR filter 39d is inserted, G
When the B filter 39c is inserted into the B memory B41c, the signal is switched and input to the B memory B41c.

The three frame memories 41a, 41b, 4
By reading the image signal data 1c at the same time, the frame sequential images sent in time series are synchronized. The digital signal output from each of the frame memories 41a, 41b, 41c is subjected to noise removal and amplification by the integration processing circuit 42.

The integration processing circuit 42 has the configuration of a recursive filter shown in FIG. 16. The input image signal is multiplied by m (1-a) by a multiplier 43 and then added by an adder 44.
And is added to the output of the multiplier 46 for multiplying by a. The output of the adder 44 is input to the frame memory 45 and also to the image processing circuit 30.

The frame memory 45 outputs an image with a delay of one frame. The coefficients of the two multipliers 43 and 46 can be rewritten by a coefficient rewriting signal output from the timing control circuit 34.

In this recursive filter, the coefficient m indicates the amplification factor, and the larger the coefficient m, the brighter the image is obtained.
When the coefficient a is increased, the afterimage effect is increased, and the noise of the image is reduced.

In the present embodiment, as shown in FIG. 17, the coefficient m is set to 1 at the time of normal observation and 2 at the time of fluorescence observation, so that a brighter image can be obtained in the case of fluorescence. The coefficient a is set to 0.1 for normal observation and 0.5 for fluorescence observation, so that noise is further reduced in the case of fluorescence. The multiplier 43 has a clipping circuit for preventing overflow of the multiplication result.

The signal output from the integration processing circuit 42 is input to the image processing circuit 30, where image processing such as image enhancement is performed, and further input to the image display control circuit 31 for display control for displaying character information. Etc. are performed. The digital signal output from the image display control circuit 31 is input to the D / A conversion circuit 32 and converted into an analog signal,
Is output to

In the automatic light control circuit 33, a signal for controlling the illumination light diaphragm 12 is transmitted so that illumination light of appropriate brightness can be obtained. The timing control circuit 34 synchronizes the rotation of the parallel rotation filter 39, the driving of the CCD, and the processing of various video signals, and the voltage applied to the liquid crystal diaphragm 38 according to the visible / infrared switching of the filter of the parallel rotation filter 39, The coefficients of the multipliers 43 and 46 are controlled.

At the time of normal light observation using visible light, a voltage is applied to the liquid crystal diaphragm 38 to reduce the diaphragm, thereby obtaining a sharp image with a deep subject depth. Further, as coefficients of the multipliers 43 and 46, m = 1 and a =
A coefficient, such as 0.1, which has little blur even in a fast motion, is substituted.

At the time of fluorescence observation using infrared light, the liquid crystal diaphragm 3
By applying a voltage to No. 8 and increasing the aperture, a bright image is obtained. As the coefficients of the multipliers 43 and 46, coefficients having a large noise reduction effect and an amplification effect, such as m = 2 and a = 0.5, are substituted. Monitor 5
Above, a normal light image or a fluorescent image can be observed according to the position of the parallel rotation filter 39.

In this embodiment, a single lamp is used as the observation light source. However, two or more light sources such as a halogen lamp for normal light observation and a laser or light emitting diode for exciting a fluorescent substance are used. They may be combined. The illumination light for exciting the fluorescent substance may be emitted from outside the body. Further, the position of the CCD 21 is not limited to the one disposed at the distal end portion 17 of the insertion section 7, but may be provided inside the processor 4B to guide light with an image guide fiber, or may be detachable from the optical endoscope. It may be arranged in the camera head. Further, an image intensifier may be provided on the front surface of the CCD 21 to improve the sensitivity.

The aperture to be used is not limited to a liquid crystal, but may be a shape memory alloy, or may be a mechanism that mechanically moves a light shielding member in and out.

This embodiment has the following effects. Since the aperture is controlled according to the switching between the fluorescence observation and the normal light observation, it is possible to observe a brighter image during the fluorescence observation and an image with a deeper depth of the subject during the normal light observation.

Also, since the coefficient of the recursive filter is changed in accordance with the switching between the fluorescence observation and the normal light observation, the fluorescence can be observed with little noise and the normal light can correspond to a fast movement.

Further, since the exposure time of the CCD 21 is changed according to the switching between the fluorescence observation and the normal light observation, weak fluorescence can be observed more brightly.

(Third Embodiment) Next, a third embodiment will be described. 18 to 21 relate to a third embodiment of the present invention. FIG. 18 is a block diagram showing the entire configuration of a fluorescence endoscope apparatus according to the third embodiment, and FIG. FIG. 20 is an explanatory diagram showing an operation at the time of fluorescence observation, and FIG. 21 is an explanatory diagram showing an operation at the same time of normal light / fluorescence observation.

An object of the present embodiment is to provide a fluorescent endoscope apparatus capable of observing both fluorescent light and ordinary light with appropriate brightness. This embodiment has a configuration similar to that of the first embodiment. Therefore, the following description will focus on the differences, and configurations having similar functions will be assigned the same reference numerals and descriptions thereof will be omitted.

The fluorescence endoscope apparatus 1C according to the third embodiment is similar to that shown in FIG.
In the fluorescence endoscope apparatus 1A, the CCD 51 in which the amplification rate is variable instead of the CCD 21 in the electronic endoscope 1A.
And an electronic endoscope 2C employing a stop 52 for limiting the amount of light passing therethrough instead of the filter stop 22, and a light source device 3C provided with a lamp emission control circuit 53 for controlling light emission of the lamp 10 in the light source device 3A. And the processor 4A
Has a processor 4C provided with a CCD drive circuit 54 for controlling the CCD 51.

The light source device 3C comprises a lamp 10 for emitting light, a band-limiting rotary filter 11 provided on the illumination optical path for limiting the transmission wavelength, an illumination light stop 12 for limiting the light amount, and a transmission wavelength, similarly to FIG. RGB rotation filter 13 to be restricted
And a condenser lens 14.
And a lamp emission control circuit 53 for controlling the emission of light.

As shown in FIG. 2, the band limiting rotary filter 11 is divided into two by a visible light transmitting filter 11a and an infrared light transmitting filter 11b. The RGB rotation filter 13 is an R, G, B filter 13 as shown in FIG.
a, 13b, and 13c.

The electronic endoscope 2C includes a light guide fiber 8 for transmitting illumination light, an illumination lens 18 disposed opposite to the distal end face, and a diaphragm 5 for limiting the amount of light passing therethrough.
2, an excitation light cut filter 23 for removing the excitation light,
It has a CCD 51 whose amplification rate is variable inside.

The processor 4C includes the preamplifier 2
4. AGC circuit 25, A / D conversion circuit 26, multiplexer circuit 27, first frame memory 28, second frame memory 29, image processing circuit 30 for processing such as image enhancement, image display control circuit 31, D / A conversion circuit 32,
An automatic dimming circuit 33 for controlling the illumination light diaphragm 12, a timing control circuit 34 for synchronizing the entire fluorescence endoscope apparatus 1C,
A CCD drive circuit 54 for controlling the CCD 51 is provided.

Further, a laser light source 6 for generating laser light for laser treatment and a laser guide 37 for guiding the laser light are provided.

Next, the operation of the endoscope apparatus 1C configured as described above will be described. A fluorescent substance having an affinity for a focus such as cancer, such as an indocyanine green (ICG) derivative-labeled antibody, has been administered to the body of the subject 19 in advance.

[0114] The lamp 10 of the light source device 3C emits light in the visible light region and in a wavelength band including the excitation wavelength of the ICG derivative-labeled antibody. The light emitted from the lamp 10 passes through the band-limiting rotation filter 11 and the illumination light stop 12,
The light passes through the RGB rotation filter 13. The light transmitted through the RGB rotation filter 13 is incident on the light guide fiber 8 of the electronic endoscope 2C.

The band limiting rotary filter 11 has the configuration shown in FIG. 2, and its spectral transmission characteristics are as shown in FIG. The RGB rotation filter 13 has the configuration shown in FIG. 4, and its spectral transmission characteristics are as shown in FIG.

At the time of normal light observation, as shown in FIG. 19, the lamp light emission control circuit 53 supplies a lamp current of, for example, 18 A in a pulse shape, and the lamp 10
Emit light in synchronization with the rotation of.

The visible light transmitting filter 11a of the band limiting rotary filter 11 is fixed on the optical path, and the RGB rotating filter 13 rotates 30 times per second, so that red, green, and blue lights are sequentially irradiated (FIG. 19). reference).

At the time of fluorescence observation, the lamp light emission control circuit 53
Supplies a current of 21 A in a pulse form as shown in FIG. 20, and the lamp 10 emits light in synchronization with the rotation of the RGB rotary filter 13.

Further, the infrared light transmitting filter 11b of the band limiting rotary filter 11 is fixed on the optical path, and the RGB rotating filter 13 rotates 30 times per second, so that the infrared light in the wavelength band of the excitation light is irradiated ( See FIG. 20).

At the time of simultaneous observation of a fluorescent image and a normal light image, FIG.
The lamp emission control circuit 53 supplies a current of 21 A or 18 A in a pulse form according to the position of the band-limiting rotary filter 11 as shown in FIG.
Emit light in synchronization with the rotation of. This RGB rotation filter 1
3 rotates 30 times per second, and the band-limited rotation filter 11 rotates 90 times per second, so that red, excitation light, green, excitation light,
It is sequentially irradiated with blue and excitation light (see FIG. 21).

At this time, the timing control circuit 34
The B-rotation filter 13 and the band-limited rotation filter 11 are controlled so as to rotate in synchronization with each other, and the lamp emission control circuit 53 is controlled to supply a predetermined current to the lamp in accordance with the switching of the band-limited rotation filter 11. .

As described above, by supplying a higher lamp current during fluorescence observation than during normal light observation, the emission intensity of fluorescence can be increased, and a bright fluorescent image can be obtained.

The reflected light and the fluorescent light from the test object 19 are imaged by the CCD 51 via the stop 52 for limiting the amount of light and the excitation light cut filter 23. The excitation light cut filter 23 is configured to block the excitation light component of the ICG derivative-labeled antibody and transmit the fluorescence component and the visible light component, and has a spectral transmission characteristic as shown in FIG. Therefore, C
The CD 51 receives red, green, blue visible light or infrared fluorescent light according to the positions of the RGB rotation filter 13 and the band-limiting rotation filter 11.

The CCD 51 used in the present embodiment is
A high amplification factor can be obtained inside the CCD 51 by utilizing the avalanche effect, and the amplification factor is controlled by the amplitude of the transfer clock. Since the amplification is performed inside the CCD 51, the influence of noise from outside is small, and by increasing the amplitude of the transfer clock to increase the amplification factor, even weak light can be observed brightly.

The CCD 51 is driven by the CCD driving circuit 54 in synchronization with the rotation of the rotary filters 11 and 13.
1 per second depending on the presence or absence of rotation of the band-limited rotation filter 11
An image of 80 frames or 90 frames per second is formed. Visible light transmission filter 1 of band-limited rotation filter 11
1a is inserted (during normal light observation), the CCD driving circuit 54
Reduces the amplitude of the transfer clock to lower the amplification factor in the CCD 51 (see FIGS. 19 and 21).

[0127] A relatively bright image can be obtained by observation with ordinary light, so a low amplification factor may be used. When the infrared light transmitting filter 11b is inserted (fluorescence observation), the amplitude of the transfer clock is increased to increase the amplification factor in the CCD 51 (see FIGS. 20 and 21). By increasing the amplification factor, weak fluorescence can be observed with sufficient brightness.

The electric signal from the CCD 51 is input to the preamplifier 24 of the processor 4C and amplified, and the gain is adjusted by the AGC circuit 25. Thereafter, the signal is input to the A / D conversion circuit 26, and is converted from an analog signal to a digital signal.

The digital signal is stored in the first frame memory 28 or the second frame memory 29 via the multiplexer 27. Based on the control signal from the timing control circuit 34, the multiplexer 27 is configured such that when the visible light transmitting filter 11a of the band limiting rotary filter 11 is inserted, the infrared light transmitting filter 11b is inserted into the first frame memory 28. When the signal is present, the signal is switched and input to the second frame memory 29.

The signals output from the first and second frame memories 28 and 29 are input to an image processing circuit 30, where image processing such as image enhancement and noise removal is performed, and further input to an image display control circuit 31. , Display control for simultaneous display of a fluorescent image, a normal image, and character information is performed.

The digital signal output from the image display control circuit 31 is input to the D / A conversion circuit 32, converted into an analog signal, and output to the monitor 5. The automatic light control circuit 33 sends a signal for controlling the illumination light diaphragm 12 so that illumination light of appropriate brightness is obtained. The timing control circuit 34 controls the rotation of the rotary filter, the driving of the CCD, the processing of various video signals, and the synchronization of lamp emission.

On the monitor 5, the band-limited rotation filter 1
The normal light image, the fluorescent image, or both of them can be simultaneously observed depending on the position of the first position. In the present embodiment, a single lamp 10 is used as the observation light source means, but for example, a combination of two or more light sources such as a halogen lamp for normal light observation and a laser or light emitting diode for exciting a fluorescent substance is used. Is also good.

The illumination light for exciting the fluorescent substance may be applied from outside the body. Also, the means for controlling the amount of illumination light is not limited to changing the lamp current.
The opening of the illumination light aperture may be controlled, or a filter for limiting the amount of light may be inserted on the illumination light path.

The position of the CCD 51 is not limited to the one disposed at the distal end portion 17 of the insertion section 7. The CCD 51 may be provided inside the processor 4C to guide light through an image guide fiber. It may be arranged in a detachable camera head. Further, the processing may be performed for each field instead of the processing for each frame.

The present embodiment has the following effects. Lamp intensity and CC according to switching between fluorescence observation and normal light observation
Since the configuration is such that the amplification factor of D51 is controlled, the brightness of the fluorescence image and the brightness of the normal observation image do not significantly differ, and both the fluorescence and the normal light can be observed with appropriate brightness.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. FIGS. 22 to 27 relate to a fourth embodiment of the present invention. FIG. 22 is a block diagram showing the overall configuration of a fluorescence endoscope apparatus according to the fourth embodiment.
3 is an explanatory view showing the configuration of an RGB rotary filter, FIG. 24 is an explanatory view showing the spectral transmission characteristics of the RGB rotary filter, and FIG.
5 is an explanatory diagram showing an operation during normal light observation, FIG. 26 is an explanatory diagram showing an operation during fluorescence observation, and FIG. 27 is an explanatory diagram showing an operation during simultaneous observation of normal light and fluorescence.

An object of the present embodiment is to provide a fluorescent endoscope apparatus which can remove light leaking from the outside during infrared fluorescent observation and can obtain a fluorescent image with less noise. This embodiment has a configuration similar to that of the first embodiment. Therefore, the following description will focus on the differences, and configurations having similar functions will be assigned the same reference numerals and descriptions thereof will be omitted.

In the fluorescence endoscope apparatus 1D according to the fourth embodiment shown in FIG. 22, an aperture 52 is employed instead of the filter aperture 22 in the electronic endoscope 2A in the fluorescence endoscope apparatus 1A shown in FIG. In the electronic endoscope 2D and the processor 4A, the output end of the multiplexer 27 is replaced by a R instead of the first frame memory 28 and the second frame memory 29.
Memory 41a, G memory 41b, B memory 41c
And R 'memory 61a, G' memory 61b,
B 'memory 61c, processor 4D provided with two subtractors 62 and 63, adder 64 and integration processing circuit 42, and RGB rotation filter 13 in light source device 3A.
And a light source device 3D using an RGB rotation filter 65 having different characteristics.

As in FIG. 1, the light source device 3D includes a lamp 10 for emitting light, a band-limiting rotary filter 11 provided on the illumination optical path for limiting the transmission wavelength, and an illumination light stop 12 for limiting the amount of light. RGB rotation filter 6 for limiting a transmission wavelength having a characteristic different from that of the first RGB rotation filter 13
5 is provided.

As shown in FIG. 2, the band limiting rotary filter 11 is divided into two by a visible light transmitting filter 11a and an infrared light transmitting filter 11b. The RGB rotation filter 65 includes an R, G, B filter 65 as shown in FIG.
a, 65b and 65c. Electronic endoscope 2D
Has a light guide fiber 8 for transmitting illumination light, a stop 52 for limiting the amount of light incident on the imaging means, an excitation light cut filter 23 for removing excitation light, and a CCD 21.

The processor 4D comprises a preamplifier 24, an AG
C circuit 25, A / D conversion circuit 26, multiplexer circuit 27, R memory 41a, G memory G41b, B memory B41c, R 'memory 61a, G' memory 61
b, B 'memory 61c, two subtractors 62 and 63, an adder 64, an integration processing circuit 42, an image processing circuit 30, an image display control circuit 31, a D / A conversion circuit 32, an illumination light diaphragm 1
And a timing control circuit 34 for synchronizing the entire fluorescence endoscope apparatus 1D.
A laser light source 6 for generating laser light for laser treatment.
And a laser guide 37 for guiding the laser light.

Next, the operation of the fluorescent endoscope apparatus 1D thus configured will be described. A fluorescent substance having an affinity for a focus such as cancer, such as an indocyanine green (ICG) derivative-labeled antibody, has been administered to the body of the subject 19 in advance.

The lamp 10 of the light source device 3D emits light in the visible light region and in a wavelength band including the excitation wavelength of the ICG derivative-labeled antibody. The light emitted from the lamp 10 passes through the band-limiting rotation filter 11 and the illumination light stop 12,
The light passes through the RGB rotation filter 65.

The light transmitted through the RGB rotation filter 65 is
The light enters the light guide fiber 8 of the electronic endoscope 2D. The band limiting rotary filter 11 has the configuration shown in FIG. 2, and its spectral transmission characteristics are as shown in FIG. The RGB rotation filter 65 has the configuration shown in FIG. 23, and its spectral transmission characteristics are as shown in FIG.

That is, the R filter 65a and the G filter 6
5b transmits the excitation light component of the infrared ICG derivative-labeled antibody, but the B filter 65c does not transmit the excitation light component.
Therefore, when the infrared light transmitting filter 11b of the band limiting rotary filter 11 is inserted in the illumination light path, if the R filter 65a or the G filter 65b is inserted, the excitation light component is irradiated, but the B filter 65c No light is emitted if is inserted.

At the time of normal light observation, the visible light transmitting filter 11a of the band limiting rotary filter 11 is fixed on the optical path.
The RGB rotation filter 65 is rotated 30 times per second, so that red, green, and blue lights are sequentially emitted (see FIG. 25).

At the time of fluorescence observation, the band-limited rotation filter 1
One infrared light transmitting filter 11b is fixed on the optical path,
The GB rotation filter 65 rotates 30 times per second,
The infrared light in the wavelength band of the excitation light is intermittently applied (FIG. 2).
6).

When simultaneously observing the fluorescent image and the normal light image, the RGB
The rotation filter 65 rotates 30 times per second, and the band-limited rotation filter 11 rotates 90 times per second, so that red, excitation light,
Irradiation is performed in the order of green, excitation light, blue, and light shielding (see FIG. 27). At this time, the timing control circuit 34 controls the RGB rotation filter 65 and the band-limited rotation filter 11 to rotate in synchronization.

The reflected light and fluorescent light from the test object 19 are imaged by the CCD 21 through the stop 52 for limiting the light amount and the excitation light cut filter 23. The excitation light cut filter 23 is configured to block the excitation light component of the ICG derivative-labeled antibody and transmit the fluorescence component and the visible light component, and has a spectral transmission characteristic as shown in FIG.

Therefore, in the CCD 21, the position of the RGB rotation filter 65 and the band-limited rotation filter 11 is
It receives red, green, blue visible light, infrared fluorescent light, or light of noise components leaking from outside the body (FIGS. 25 to 25).
See FIG. 27).

The CCD 21 is driven by a CCD driving circuit (not shown) in synchronization with the rotation of the rotation filters 11 and 65, and forms an image of 180 frames per second or 90 frames per second depending on whether or not the band-limiting rotation filter 11 rotates. .

The electric signal from the CCD 21 is input to the preamplifier 24 of the processor 4D and amplified, and the gain is adjusted by the AGC circuit 25. Thereafter, the signal is input to the A / D conversion circuit 26, and is converted from an analog signal to a digital signal.

The digital signal is transmitted to the six frame memories 41a to 41c and 61a to 61c through the multiplexer 27.
1c. The multiplexer 27
Based on a control signal from the timing control circuit 34, a memory for storing an image is selected.

When the visible light transmitting filter 11a of the band limiting rotary filter 11 is inserted on the illumination optical path,
In accordance with the position of the RGB rotation filter 65, the R memory 4
1a, the image signal is stored in the G memory 41b and the B memory 41c. That is, the image for irradiation in red is stored in the R memory 41a, the image for irradiation in green is stored in the memory for G 41b, and the image for irradiation in blue is stored in the memory 41c for B.

When the infrared light transmitting filter 11b is inserted on the illumination light path, the R 'memory 61a, the G' memory 61b,
The image signal is stored in the B 'memory 61c. That is,
The R 'memory 61a and the G' memory 61b store a fluorescent image, and the B 'memory 61c stores an image (background image) without illumination light.

The background image represents noise due to light leaking from outside the body and stationary noise inherent to the device. These background noise components do not cause much problem during normal observation, but become a serious problem when observing weak fluorescence.

In particular, light in the near-infrared region has good permeability to living tissues due to little absorption of hemoglobin and water, and in the case of fluorescence observation in the near-infrared region such as an ICG derivative-labeled antibody, the light from the outside of the subject is likely to be present. Leakage is a problem.

Since the two subtractors 62 and 63 subtract the background image from the fluorescent image, these background noise components are removed. The two fluorescent images from which the background noise component has been removed are added by the adder 64, and the added signal is shown in FIG.
6 is input to the integration processing circuit 42 having the configuration shown in FIG. 6 to remove temporally non-stationary noise components.

R memory 41a, G memory 41b, B memory
The signals output from the memory for memory 41c and the integration processing circuit 42 are input to the image processing circuit 30, where image processing such as image enhancement and noise removal is performed, and further, the image display control circuit 31
And display control for simultaneous display of a fluorescent image, a normal image, and character information is performed.

The digital signal output from the image display control circuit 31 is input to the D / A conversion circuit 32, converted into an analog signal, and output to the monitor 5. The automatic light control circuit 33 sends a signal for controlling the illumination light diaphragm 12 so that illumination light of appropriate brightness is obtained. The timing control circuit 34 controls the rotation of the rotary filter, the driving of the CCD, and the synchronization of various video signal processes.

On the monitor 5, the band-limited rotation filter 1
The normal light image, the fluorescent image, or both of them can be simultaneously observed depending on the position of the first position. In the present embodiment, a single lamp 10 is used as the observation light source means, but for example, a combination of two or more light sources such as a halogen lamp for normal light observation and a laser or light emitting diode for exciting a fluorescent substance is used. Is also good.

Further, the illumination light for exciting the fluorescent substance may be applied from outside the body. Further, the position of the CCD 21 is not limited to the one disposed at the distal end portion 17 of the insertion section 7, and may be provided inside the processor 4D to guide light with an image guide fiber, or may be detachable from the optical endoscope. It may be arranged in the camera head. Further, the processing may be performed for each field instead of the processing for each frame.
This embodiment has the following effects. Since the difference between the fluorescent image when the excitation light is irradiated and the background image when the light is not irradiated is taken, a fluorescent image with less noise due to external leakage light can be obtained. An embodiment configured by partially combining the above-described embodiments and the like also belongs to the present invention.

[Supplementary Notes] In an apparatus for diagnosing by administering a fluorescent substance to an object to be inspected, light of a first wavelength band including an excitation wavelength of the fluorescent substance and light of a second wavelength band including visible light are applied to the object to be inspected. Light source means for irradiating the object to be inspected, an image pickup means for picking up a visible light image of the object to be inspected and a fluorescent image of the fluorescent substance, and a diaphragm means inserted in an optical path between the object to be inspected and the image pickup means The diaphragm means has a visible light transmitting portion that transmits visible light and a visible light that does not transmit visible light but transmits light in a wavelength band of fluorescence of the fluorescent substance, and has a larger transmission area than the visible light transmitting portion. A fluorescent endoscope device having a non-transmissive part.

(Purpose of Supplementary Note 1 and Supplementary Note 2) Provided is a fluorescent endoscope apparatus which can be brighter during fluorescence observation and can be observed at a deeper depth of field during normal light observation. (Function of Supplementary Note 1) Since the area through which the fluorescent light is transmitted in the aperture portion is made larger than the area through which visible light (normal light) passes, a large amount of fluorescent light can pass through the aperture portion, and the fluorescent light is brighter. Light can be observed at a deeper depth of field.

[0164] 2. In a fluorescence endoscope apparatus for diagnosing by observing fluorescence emitted from a fluorescent substance, a second endoscope including visible light and light in a first wavelength band including an excitation wavelength of the fluorescent substance.
Light source means for selectively irradiating light of the wavelength band of the object to be inspected, switching means for switching between light of the first wavelength band and light of the second wavelength band, Imaging means for capturing a visible light image and a fluorescent image of the fluorescent substance; variable aperture means inserted on an optical path between the object to be inspected and the imaging means; and the variable aperture according to switching of the switching means A fluorescent endoscope apparatus characterized by controlling means.

(Function of Supplementary Note 2) Since the aperture is controlled in accordance with the switching between the fluorescence observation and the normal light observation, the fluorescence is increased by increasing the aperture during the fluorescence observation and decreasing the aperture during the normal light observation. Bright, normal light can be observed at a deeper depth of field.

3. In a fluorescence endoscope apparatus for diagnosing by observing fluorescence emitted from a fluorescent substance, a second endoscope including visible light and light in a first wavelength band including an excitation wavelength of the fluorescent substance.
Light source means for selectively irradiating light of the wavelength band of the object to be inspected, switching means for switching between light of the first wavelength band and light of the second wavelength band, Imaging means for imaging a visible light image and a fluorescent image of the fluorescent substance; integrating means for integrating an image signal obtained by the imaging means; and controlling the integrating means in accordance with switching of the switching means. Fluorescent endoscope device.

(Supplementary Note 3) To provide a fluorescence endoscope apparatus which can observe with less noise at the time of fluorescence observation and can respond to a fast movement at the time of normal light observation. (Operation of Supplementary Note 3) Since the integration means is controlled in accordance with switching between the fluorescence observation and the normal light observation, the fluorescence can be observed with little noise and the normal light can correspond to a fast movement.

4. In a fluorescence endoscope apparatus for diagnosing by observing fluorescence emitted from a fluorescent substance, a second endoscope including visible light and light in a first wavelength band including an excitation wavelength of the fluorescent substance.
Light source means for selectively irradiating light of the wavelength band to the object to be inspected, light amount control means for controlling the light amount of the light source means, light of the first wavelength band and light of the second wavelength band Switching means for switching light, imaging means for capturing a visible light image of the inspection object and a fluorescent image of the fluorescent substance,
A fluorescence endoscope apparatus wherein the light amount control means is controlled in accordance with the switching of the switching means.

(Purposes of Supplementary Note 4 and Supplementary Note 5) An object of the present invention is to provide a fluorescent endoscope apparatus capable of observing both normal light and fluorescent light at appropriate brightness. (Function of Supplementary Note 4) Since the configuration is such that the light amount is controlled in accordance with the switching between the fluorescence observation and the normal light observation, both the fluorescence and the normal light can be observed with appropriate brightness.

[0170] 5. In a fluorescence endoscope apparatus for diagnosing by observing fluorescence emitted from a fluorescent substance, a second endoscope including visible light and light in a first wavelength band including an excitation wavelength of the fluorescent substance.
Light source means for selectively irradiating light of the wavelength band of the object to be inspected, switching means for switching between light of the first wavelength band and light of the second wavelength band, Imaging means for imaging a visible light image and a fluorescent image of the fluorescent substance; amplifying means for amplifying an image signal obtained by the imaging means; and controlling the amplifying means in accordance with switching of the switching means. Fluorescent endoscope device. (Function of Supplementary Note 5) Since the amplifier is controlled in accordance with the switching between the fluorescence observation and the normal light observation, both the fluorescence and the normal light can be observed with appropriate brightness.

6. In a fluorescent endoscope apparatus that performs a diagnosis by administering a fluorescent substance to a test object, a light source unit that intermittently irradiates light to the test object and a light source unit that irradiates light from the light source unit. An imaging unit that captures a fluorescent image from the inspection object and a background image from the inspection object when light is not emitted from the light source unit; and calculates a difference between the fluorescence image and the background image. And an subtracting means for performing the subtraction.

(Supplementary Note 6) An object of the present invention is to provide a fluorescent endoscope apparatus capable of removing light leaking from the outside during infrared fluorescent observation and obtaining a fluorescent image with less noise. (Function of Supplementary Note 6) Since the difference between the fluorescent image and the background image when no light is irradiated is taken, a fluorescent image with less noise can be obtained.

[0173]

As described above, according to the present invention, in a fluorescence endoscope apparatus for diagnosing by administering a fluorescent substance to an object to be inspected, a first wavelength band including an excitation wavelength of the fluorescent substance is provided. Light source means for irradiating the object to be inspected with light in a second wavelength band including light and visible light, imaging means for imaging a visible light image of the object to be inspected and a fluorescent image of the fluorescent substance, Diaphragm means inserted in the optical path between the object to be inspected and the imaging means, wherein the diaphragm means transmits a visible light through a visible light transmitting portion and does not transmit visible light; The visible light is transmitted through a wavelength band of the visible light transmitting portion, and the visible light transmitting portion is configured to have a visible light non-transmitting portion that is larger than the visible light transmitting portion. Is an image with a deep depth of field,
The fluorescent light is transmitted by the diaphragm means without being narrowed down compared with the case of visible light, and therefore, an image based on the fluorescent light can obtain a brighter image suitable for diagnosis.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a fluorescence endoscope apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a band-limited rotation filter.

FIG. 3 is a characteristic diagram showing a spectral transmission characteristic of a band-limited rotation filter.

FIG. 4 is a configuration diagram of an RGB rotation filter.

FIG. 5 is a characteristic diagram showing a spectral transmission characteristic of an RGB rotation filter.

FIG. 6 is a configuration diagram of a filter stop.

FIG. 7 is a characteristic diagram showing a spectral transmission characteristic of a filter stop.

FIG. 8 is a characteristic diagram showing a spectral transmission characteristic of an excitation light cut filter.

FIG. 9 is an explanatory diagram of an operation during normal light observation.

FIG. 10 is an explanatory diagram of an operation during fluorescence observation.

FIG. 11 is an explanatory diagram of the operation at the time of normal light / fluorescence simultaneous observation.

FIG. 12 is an overall configuration diagram of a fluorescence endoscope apparatus according to a second embodiment of the present invention.

FIG. 13 is a configuration diagram of a parallel rotation filter.

FIG. 14 is a characteristic diagram showing a spectral transmission characteristic of a parallel rotation filter.

FIG. 15 is a configuration diagram of a liquid crystal diaphragm.

FIG. 16 is a configuration diagram of an integration processing circuit.

FIG. 17 is an operation explanatory view of the second embodiment.

FIG. 18 is an overall configuration diagram of a fluorescence endoscope apparatus according to a third embodiment of the present invention.

FIG. 19 is an explanatory diagram of an operation during normal light observation.

FIG. 20 is an operation explanatory view at the time of fluorescence observation.

FIG. 21 is an explanatory diagram of the operation during simultaneous observation of normal light and fluorescence.

FIG. 22 is an overall configuration diagram of a fluorescence endoscope apparatus according to a fourth embodiment of the present invention.

FIG. 23 is a configuration diagram of an RGB rotation filter.

FIG. 24 is a characteristic diagram showing a spectral transmission characteristic of an RGB rotation filter.

FIG. 25 is an explanatory diagram of the operation during normal light observation.

FIG. 26 is an operation explanatory view at the time of fluorescence observation.

FIG. 27 is an explanatory diagram of the operation at the time of normal light / fluorescence simultaneous observation.

[Explanation of symbols]

 1A: Fluorescent endoscope device 2A: Electronic endoscope 3A: Light source device 4A: Processor 5: Monitor 6: Laser light source 7: Insertion unit 8: Light guide fiber 10: Lamp 11: Band-limited rotary filter 11a: Visible light transmission Filter 11b Infrared light transmission filter 12 Illumination light stop 13 RGB rotation filter 15, 16 Motor 21 CCD 22 Filter stop 22a Visible light transmitting part 22b Visible light non-transmitting part 22c Light shielding part 23 Excitation Optical cut filter 24 ... Preamplifier 25 ... AGC circuit 26 ... A / D conversion circuit 27 ... Multiplexer 28,29 ... Frame memory 30 ... Image processing circuit 31 ... Image display control circuit 32 ... D / A conversion circuit 33 ... Automatic light control circuit 34 ... Timing control circuit

Claims (1)

[Claims] 1. A fluorescent endoscope apparatus for diagnosing a subject by administering a fluorescent substance to a subject to be inspected, wherein a light in a first wavelength band including an excitation wavelength of the fluorescent substance and a second wavelength including visible light. Light source means for irradiating light of a band to the object to be inspected; imaging means for imaging a visible light image of the object to be inspected and a fluorescent image of the fluorescent substance; and Diaphragm means inserted on an optical path, the diaphragm means transmits a visible light transmitting portion that transmits visible light, and transmits light in a fluorescent wavelength band of the fluorescent substance without transmitting visible light; A fluorescent endoscope apparatus having a visible light non-transmitting part having a larger transmission area than a light transmitting part.