JPH1156751A - Endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope which is suitably designed to obtain an endoscopic image within a range where a tomograph by low interference light is obtained. SOLUTION: In this endoscope, low interference light from a SLD 24 is guided to the tip of an endoscope 2 by the second single mode fiber 28, is radiated to a bio tissue 13 through a scanning mechanism 35, and the first lens 15, and the reflected light is mixed with reference light through the reverse light path and received by a light detection means, and the interference light component is extracted, then a tomograph corresponding to the scanning in the depth direction of the bio tissue 13 is displayed on a monitor 6. An objective optics 14 for a normal observation has a zoom lens 16, and by enlargement using the zoom lens 16, the depth of field is set so that it is approximately coincide with the display range in the depth direction of the tomograph. When the tip of the endoscope 2 is deviated from a range where a tomograph by a low interference light is obtained, an endoscopic image by an imaging means using the objective optics 14 becomes dim, so it is easy to keep an endoscopic image within a range where a tomograph is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope having a function of obtaining an optical tomographic image of a living tissue.

[0002]

2. Description of the Related Art In recent years, when diagnosing a living tissue, an optical CT device capable of obtaining optical information inside the tissue has been proposed in addition to an imaging device for obtaining optical information on the surface state of the tissue. .

The optical CT apparatus uses picosecond pulses to detect information inside a living body and obtain a tomographic image. However, laser light sources that generate extremely short pulse light on the order of picosecond pulses are expensive, large, and cumbersome to handle.

[0004] Recently, an interference type OCT (optical optical system) for obtaining a tomographic image of a subject using low coherence light has been proposed.
Coherence tomography) is disclosed, for example, in US Patent No. 5,321,501.

In this conventional example, when observing a body cavity in the digestive tract or the like, since the OCT probe is inserted into a channel of the endoscope for observation, the positional relationship between the endoscope and the OCT is uncertain, and the endoscope is invisible. There is a problem that the positional relationship between the observation image of the mirror and the tomographic image of the living tissue by OCT is difficult to understand.

For this reason, the applicant of the present invention has disclosed, for example, in
As disclosed in Japanese Patent No. 54228, an endoscope that can obtain a tomographic image by OCT for a tissue inside a body cavity has been proposed.

[0007]

In a conventional endoscope, the depth of field of an observation optical system for obtaining a normal endoscope image is much wider than the depth of a tomographic image obtained by OCT. Below, there is a problem that it is easy to deviate more than the depth obtained by OCT, and if it deviates, a tomographic image with sufficient resolution for diagnosis cannot be obtained.

The present invention has been made in view of the above points, and has as its object to provide an endoscope suitable for obtaining an endoscope image while maintaining a distance range in which a tomographic image by OCT can be obtained. .

[0009]

A light guide for illuminating a specific portion of a subject, a solid-state imaging device for observing the specific portion, and an objective optical system are provided, and can be inserted into the subject. In an endoscope having a simple insertion portion, the object is illuminated with low-interference light, and means for imaging the inside of the object with reflected and scattered light are used. A light guide for detecting the reflected light reflected from the sample, a condenser lens for condensing the low interference light from the light guide on the subject, and scanning light emitted from the condenser lens Scanning means for scanning, the scanned light is scanned within the observation range of the objective optical system, arranged between the scanning means and the objective optical system,
A coupling unit for optically coupling these components is built into the endoscope, and a range on a deep side that can be imaged by the low interference light substantially matches a range of a depth of field that can be observed by the solid-state imaging device. By doing so, when the image is deviated from the deep area where the image can be formed by the low interference light, the image obtained by the solid-state imaging device is blurred, and both images can be easily maintained in a state where both images can be clearly observed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows an endoscope apparatus 1 provided with a first embodiment of the present invention. The endoscope apparatus 1 includes an endoscope 2 according to the first embodiment having a built-in imaging unit, a light source apparatus 3 that supplies illumination light of visible light to the endoscope 2,
A low-interference OCT unit 4 for obtaining a low-coherence tomographic image by low-interference light, a signal processing unit 5 for performing signal processing on an output signal of the imaging unit and the OCT unit 4, and a video signal output from the signal processing unit 5 And a monitor 6 for displaying.

The endoscope 2 has an elongated insertion portion 7 to be inserted into a body cavity. A light guide 8 for transmitting visible light is inserted into the insertion portion 7, and an incident end portion on the base end side thereof. Is connected to the light source device 3. Then, white illumination light generated by the lamp 9 of the light source device 3 is incident on the incident end of the light guide 8 via the condenser lens 10, and
From the front end face fixed to the illumination window
Then, it is irradiated to the living tissue (subject) 13 side such as a diseased part in front, and illuminates the living tissue 13 side.

A first lens 15 forming an objective optical system 14 is fixed to an observation window formed adjacent to the illumination window, and a zoom lens 16 is actuated behind the first lens 15 via a half mirror 17 by an actuator 18 via an optical axis O. The first lens 15 and the zoom lens 16 are arranged at image-forming positions such as a charge-coupled device (C).
19) are arranged.

When the zoom lens 16 is moved by the actuator 18, by operating a zoom switch (not shown), a corresponding drive signal is output from the control circuit 34 to the actuator 18 by an instruction signal to move the zoom lens 16 to the enlargement side. Move to etc.

The imaging signal photoelectrically converted by the CCD 19 is input to the CCU 21 in the signal processing unit 5, and the CCU 21
After being converted into a digital video signal by 21, the endoscope image is displayed on the endoscope image display area 23 of the monitor 6 via the scan converter 22.

The low-interference OCT unit 4 is, for example, an SLD (Supe) having a wavelength of 1300 nm as a light source for generating low-interference light.
The SLD 24 has a characteristic of low coherence light that shows coherence only in a short range such as about 17 μm.

The light of the SLD 24 is incident on one end of a first single mode fiber 26 via a lens 25,
It is transmitted to the other end surface (tip surface). An optical coupler 27 is provided in the middle of the first single mode fiber 26, and is optically coupled to a second single mode fiber 28. Therefore, the light is split and transmitted by the optical coupler 27.

A loop portion 29 is provided in the middle of the first single mode fiber 26 near the other end (from the optical coupler portion 27), and further has a variable optical path length facing the other end on the tip side. A mechanism is provided.

That is, the first single mode fiber 26
A lens 31 and a mirror 32 are arranged in opposition to the front end surface of the lens, and the mirror 32 is movable by an actuator 33 as shown by an arrow a so that the optical path length can be changed.

The loop portion 29 is set to have a length substantially equal to the length of the portion of the second single mode fiber 28 inserted into the endoscope 2, and from the distal end surface of the first single mode fiber 26. The optical path length reflected by the mirror 32 and returning to the distal end surface of the first single mode fiber 26 is irradiated from the distal end surface of the second single mode fiber 28 to the living tissue 13 via the lens 36 and the like,
The optical path length is set to be equal to the optical path length that is reflected inside the vicinity of the surface of the living tissue 13 and returns to the distal end surface of the second single mode fiber 28.

By shifting the position of the mirror 32 in the direction of the arrow a via the actuator 33, the optical path length on the reference light side (reference light side) is changed, and the optical path length on the measurement light side which interferes with this is changed. (More specifically, the optical path length in the depth direction of the living tissue 13) can be changed.

By setting the optical path length, return light from the depth equal to the optical path length in the light emitted toward the living tissue 13 and reflected near the surface and returned is detected as interference light. In other words, by changing the optical path length, it is possible to detect as a coherent light component at a portion having different depths in the light reflected back from the living tissue 13 and obtain a tomographic image in the depth direction. .
Note that the actuator 33 for moving the mirror 32 has a CP
U and the like are controlled by a control circuit 34.

Further, due to the optical coupling in the optical coupler section 27, the distal end side of the second single mode fiber 28 for guiding the low interference light from the SLD 24 is inserted through the insertion section 7 of the endoscope 2, and Scanning mechanism 35 by guiding interference light
The light can be emitted toward the living tissue 13 via the like.

That is, the tip of the second single mode fiber 28 disposed in the insertion section 7 is fixed to the vicinity of the tip 11 of the insertion section 7 and the lens 36 disposed opposite to the tip face of the second single mode fiber 28 The light is reflected at right angles by a fixed mirror 37 disposed at the front position, reflected at the front side by a first scanning mirror 38, and reflected at right angles by a second scanning mirror 39 disposed at the front side. , Into the half mirror 17 and the half mirror 1
At 7, the light is reflected to the front side, and is irradiated to the living tissue 13 side via the first lens 15 for focusing.

The first scanning mirror 38 forming the scanning mechanism 35 has the structure shown in FIG.
The second scanning mirror 39 scans the low-interference light by rotating as shown by the arrow c in FIG. The driving of the scanning mechanism 35 is also controlled by, for example, the control circuit 34. The scanning direction of the scanning mechanism 35 can be selectively set via the control circuit 34 by a scanning instruction switch (not shown) or the like. Also,
The mouse 49 connected to the CCU 21 allows the cursor 48 to select and set the scanning direction and the scanning range from the endoscope image via the control circuit 34.
FIG. 1 shows a state in which the scanning direction and one end of the scanning range are selectively set.

The light reflected or scattered on the surface or inside of the living tissue 13 follows the opposite optical path (as compared with the irradiation on the living tissue 13 side) and is incident on the distal end surface of the second single mode fiber 28. The light is mixed with the light reflected on the distal end side of the first single mode fiber 26 by the optical coupler 27 and emitted from the base end of the second single mode fiber 28.

At the base end of the second single mode fiber 25, for example, a photodiode 4
After being photoelectrically converted by the photodiode 41 and amplified by the amplifier 42, it is input to the image processing device 43 in the signal processing unit 5.

The image processing device 43 has image processing means for extracting the signal component of the interference light, and scans the low interference light by the scanning mechanism 35 via the control circuit 34, for example, to scan an address corresponding to the scanning. The image processing device 4
3 temporarily store the image data in an internal image memory.

When the operator controls the control circuit 34 to set, for example, a scanning direction, a signal corresponding to the scanning is input from the control circuit 34 to the image processing device 43, and an address corresponding to the scanning is input. To store in the image memory. The image data stored in the image memory of the image processing device 43 is output to the monitor 6 via the scan converter 22.
A tomographic image or an OCT image is displayed in the CT image display area 44.

The output signal of the CCU 21 is input to the measurement processing device 45, and the measurement processing device 45 performs a process of measuring the irradiation position of the SLD 24 and its scanning range from the image captured by the CCD 19.

The CCD 19 has a photoelectric conversion characteristic (sensitivity to light of this wavelength) of the SLD 24 with respect to the wavelength of the low interference light. The shape can be determined.

When the endoscope image and the OCT image displayed on the monitor 6 are simultaneously displayed, the scanning direction in the OCT image is set to, for example, vertical and the depth direction is displayed horizontally.
A control signal is sent to the scan converter 22 so that the vertical direction of the endoscope image displayed adjacent thereto matches the scanning direction and the display unit also matches, and is displayed on the monitor 6 via the scan converter 22. Endoscope image and OCT
Measurement processing is performed so that comparison with an image or diagnosis can be easily performed.

In this embodiment, the normal endoscope observation side,
Alternatively, by providing the zoom lens 16 in the optical system on the endoscope imaging side, the depth of field by this optical system and the range in the depth direction of the tomographic image that can be imaged by the low interference light are made to substantially match. It is characterized by being able to do things.

Next, the operation of the present embodiment will be described. The living tissue 13 side is illuminated via the illumination lens 12 by guiding the illumination light from the light source device 3 with the light guide 8. The illuminated living tissue 13 is moved by the objective optical system 14.
After being formed on the CCD 19 and subjected to signal processing by the CCU 21, an endoscope image is displayed on the monitor 6 via the scan converter 22 and the like.

On the other hand, a part of the low interference light of the SLD 24 is transferred from the first single mode fiber 26 to the second single mode fiber 28 by the optical coupler 27, and the scanning mechanism and the first lens Is applied to the living tissue 13 side.

Then, the surface of the living tissue 13 and the internal tissue near the surface of the living tissue 13 are reflected at different portions (portions where the refractive index changes), and a part thereof passes through the optical path opposite to that at the time of irradiation and the second portion. Of the reference light side (mirror 3).
(Light reflected at 2) and the photodiode 41
And is photoelectrically converted into an electric signal.

This signal is input to the image processing device 43,
By the demodulation circuit in the image processing device 43, only the interference light component is extracted and detected. The image processing device 43 scans the living tissue 13 in an arbitrary direction in the two-dimensional area by changing the scanning direction by the scanning mechanism 35 via the control circuit 34 or changing the optical path length by moving the mirror 32. At this time, a tomographic image in the depth direction can be obtained.

For example, when observing a site of interest such as an affected part in an endoscope image and wishing to observe the internal state, the zoom lens 16 is set to an enlarged state by operating a zoom switch or the like. The cursor 47 is used to indicate the scanning direction and scanning range on the endoscope image as shown in FIG.

The control circuit 34 drives the scanning mechanism 35 in accordance with the designated scanning range and scanning direction with reference to the magnification information (or movement information) of the zoom lens 16 (the magnification of the zoom lens 16 is determined, etc.). In this case, the angle of view (imaging range) is determined, and information necessary for scanning an arbitrary designated angle of view at the angle of view is stored in a storage means (ROM or the like) not shown in the control circuit 34 or the like. There). In the case of FIG. 1, the first scanning mirror 3
By driving only 8 at a predetermined angle, the specified upper and lower ranges are scanned.

Then, the scanning range corresponding to the instruction is scanned with the low interference light. In this case, for example, the mirror 32
Is moved to change the optical path length on the reference light side to obtain tomographic image data in the depth direction. Then, the first scanning mirror 38 is driven so as to sequentially shift the scan angle (in the case of an arbitrary scan direction, Drive both the first scanning mirror 38 and the second scanning mirror 39).

Then, by scanning the designated range, tomographic image data for the scanning range is stored in the image memory of the image processing device 43, and the tomographic image is displayed on the monitor 6 via the scan converter 22. You.

When an endoscope image and a tomographic image are simultaneously displayed on the monitor 6, an instruction to display the endoscope image and the tomographic image so as to be easily compared is issued. The range is detected, and further, by referring to the magnification information of the zoom lens 16 from the control circuit 34, the scanning direction of the low interference light in the endoscopic image is displayed on the vertical axis, and the depth direction is displayed on the horizontal axis, The display is performed as shown in FIG. 1 so that the unit lengths in the vertical direction match each other.

For example, in the state of FIG. 1, the tomographic image at the height of the position of the symbol a in the endoscope image is along the horizontal line b. In this state, since the cross section of the vertical line indicating the scanning range on the endoscope image is displayed as a tomographic image, it is easy to make a comparison, and it is easy to diagnose how the inside of the surface of the affected part or the like is from the tomographic image.

In the present embodiment, when the distal end side of the endoscope 2 is set to a position near a distance where a predetermined depth range can be obtained as a tomographic image with respect to the living tissue 13, the zoom lens 16 is used. The depth of field is set so that the surface 13 can be observed in a focused state.

Accordingly, in this state, the endoscope image is clearly displayed, and a tomographic image can be obtained in a state close to the focus state. Then, from this state (that is, from a state where a tomographic image in a predetermined range is obtained in the depth direction), the living tissue 13
When the distal end of the endoscope 2 is moved (in a direction in which the distance from the living tissue 13 changes) with respect to the direction in which the tomographic image is obtained, the endoscope image is blurred. Therefore, it is possible to prevent the user from inadvertently shifting from this observation state. That is, it is easy to maintain a state where both images can be obtained clearly. In addition, since the affected part or the like can be enlarged and displayed by the zoom lens 16, the shape of the affected part or the like can be known in detail, and it is easy to determine, for example, whether the affected part is a benign tissue or a malignant tissue, In this case, detailed internal information based on the tomographic image can be effectively used.

On the other hand, in the conventional example, since the depth of field on the endoscope side is much larger than the range in the depth direction for obtaining a tomographic image, the endoscope image does not become unclear even if the distance is changed. Therefore, the endoscope image is clearly displayed, but the tomographic image in a state close to the focus state cannot be obtained, and the tomographic image cannot be used for diagnosis. Was often.

As described above, according to the present embodiment, it is easy to maintain the endoscope image and the tomographic image in a clear state so that they can be easily used for diagnosis, and to display both images in a state where they can be easily compared. That is, since the resolution of the endoscope image and the resolution of the tomographic image are displayed substantially in agreement, it is easy to compare the two images. In this case, at least the resolution in the vertical direction can be made equal. Further, the vertical and horizontal directions may be isotropically displayed on the same scale, or may be displayed on the same scale in the depth direction.

Therefore, according to the present embodiment, it is possible to provide the endoscope 2 suitable for easily obtaining an image which can be easily diagnosed, and it is easy to maintain the observation state in which the diagnosis is easy. Further, since the resolution of the endoscope image can be increased similarly to the resolution of the tomographic image, an image suitable for diagnosis can be provided to the operator.

In the display on the monitor 6 shown in FIG.
The display range of the vertical tomographic image and the vertical display range of the endoscope image may be displayed so as to match. In the above-described embodiment, the zoom lens 16 is provided, and the actuator 1
By moving the zoom lens 16 at 8, the depth of field of the imaging means and the range in which a tomographic image in the depth direction is obtained by the low interference light are made to substantially match. May be moved.

In addition to the zoom lens 16, for example, a magnifying lens is provided in the objective optical system, and when the magnifying lens is moved from a normal state to a predetermined position on the magnifying side, the depth of field of the magnifying lens is low. May be substantially the same as the range in which a tomographic image in the depth direction is obtained.

Further, by mounting an adapter or the like at the end of the endoscope 2,
The endoscope imaging means may be set in an enlarged state by the optical system of the adapter so that the depth of field substantially matches the range in which a tomographic image in the depth direction can be obtained with low interference light.
Further, although the endoscope image and the tomographic image are simultaneously displayed in FIG. 1, both images may be displayed alternately or switched and displayed.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. FIG.
Shows the overall configuration of the optical tomographic imaging apparatus, FIG. 3 shows the structure on the tip side of the probe, and FIG. 4 shows the state of optical scanning.
In the present embodiment, a wide area from the front to the side of the probe can be easily optically scanned to obtain a tomographic image within the area, so that the area can be scanned without replacing the probe. did.

The optical tomographic imaging apparatus 51 shown in FIG.
2, the low interference light from the SLD 52 is incident on a half mirror 53 for mixing light, and the light transmitted through the half mirror 53 is used as first and second scanning mirrors 55a and 55b forming an optical scanning mechanism 54. Through the light guide probe 56. The first and second scanning mirrors 55a and 55b are driven by driving means (not shown) as indicated by reference numerals d and e, and the driving of the driving means is controlled by the control unit 57.

In the light guide probe 56, a fiber bundle 58 in which a number of single mode fibers are bundled concentrically and bundled in a probe insertion portion formed by an elongated tube is housed and arranged in the longitudinal direction, and one end near the hand side. The light enters through the optical scanning mechanism 54 and exits from the other end through the wide-angle lens system 59 to the front side. Then, the light reflected by the front subject follows the reverse optical path (as compared with the case where the light is emitted) and returns to the half mirror 53 side, and the light reflected by the half mirror 53 forms a light detecting means. The light enters the photodiode 60 and is photoelectrically converted.

The light reflected by the half mirror 53 passes through three fixed mirrors 61a, 61b and 61c and is incident on a reflector 62 which is movable in a direction indicated by an arrow f by an actuator 63. The driving by the actuator 63 is controlled by the control unit 57.

The light reflected by the reflector 62 follows the reverse optical path, returns to the half mirror 53 side, and the light transmitted through the half mirror 53 enters the photodiode 60,
Photoelectric conversion is performed. That is, the light from the light guide probe 56 side and the light reflected by the reflector 62 on the reference light side are mixed and incident on the photodiode 60 by the half mirror 53.

The signal photoelectrically converted by the photodiode 60 is amplified by an amplifier 65 and then input to an image processing unit 66 to perform a process of extracting a signal component that has undergone optical interference, and to perform an operation of an actuator 63 via a control unit 57. And a process of driving the optical scanning mechanism 54 to obtain image data of a tomographic image.

The image data obtained by the image processing section 66 is temporarily stored in an internal image memory 66a, and the image data stored in the image memory 66a is output to a monitor 67. One tomographic image or two tomographic images 67a and 67b can be simultaneously displayed as shown in FIG.

When the first scanning mirror 55a is driven, the position of the light incident on the fiber bundle 58 changes, so that the position of the light emitted from the front end side also changes. FIG. 3 shows a state where the light is further emitted forward from the tip of the fiber bundle 58 through the wide-angle lens system 59 in this case.

For example, light incident on the base end surface of the fiber bundle 58 by the first scanning mirror 55a on the peripheral side, for example, below the center of the base end surface of the fiber bundle 58 is transmitted by the fiber on which the light is incident, and the distal end surface of the fiber bundle 58 In this case, the light is emitted upward through a convex lens 59a and two concave lenses 59b and 59c forming a wide-angle lens system 59 as shown by a thin line.

The light incident on the center of the base end face of the fiber bundle 58 is transmitted by the fiber on which the light is incident, and emitted from the center position on the distal end face of the fiber bundle 58. It is emitted forward along the axis.

Further, a peripheral side opposite to the lower side,
That is, the light incident on the upper position is transmitted, and emitted downward from the distal end surface of the fiber bundle 58 via an optical path indicated by a dotted line.

That is, the first scanning mirror 55a
By sequentially scanning the base end face of the fiber bundle 58 upward from below, it is possible to scan from the upper side to the lower side at a wider angle via the wide-angle lens system 59.

On the other hand, when the second scanning mirror 55b is driven, the low interference light scans the fiber bundle 58 in a direction perpendicular to the first scanning mirror. Therefore, when driving the optical scanning mechanism 54,
For example, when the second scanning mirror 55b is driven in synchronization with the driving of the first scanning mirror 55a, the fiber bundle 58 is provided with concentrically arranged fibers having a specified radius as shown in FIG. It can scan in the circumferential direction.

By sequentially changing the scanning radius and scanning, a circular area can be scanned. Further, the wide-angle lens system 5 faces the distal end face of the fiber bundle 58.
Since 9 is arranged, it is possible to optically scan a wider area of the subject corresponding to the circular area.

A display instruction means 68 such as a keyboard and a mouse is connected to the image processing section 66, and when the operator instructs a cross section in a desired direction, the image processing section 66 is stored in the image memory 66a. From the obtained image data, the image data of the corresponding section is output to the monitor 67 side,
The tomographic images 67a, 67b and the like corresponding to the cross section in the indicated direction can be displayed on the display surface of the monitor 67.

Next, the operation of the present embodiment will be described. SL
The light of D52 passes through the half mirror 53, passes through the optical scanning mechanism 54, is guided by the single mode fiber constituting the fiber bundle 58, and is emitted through the wide-angle lens system 59 at the tip of the probe 56.

When the outermost periphery of the fiber bundle 58 is scanned, light is largely bent by the wide-angle lens system 59,
Scan the side of the body lumen. When scanning near the center of the fiber bundle 58, the wide-angle lens system 5
At 9, the light is not bent so much and scans near the front of the living body.

As described above, by changing the scan radius of the fiber bundle 56, the scan direction can be changed over a wide range from the front to the side. If these tomographic images are stored in a memory and combined, a three-dimensional tomographic image can be easily constructed.

Since no mechanical variable means is required at the tip of the probe 56, the diameter of the probe 56 can be reduced. Further, since the circumferential scan can be performed without rotating the fiber bundle 56 as the light guide fiber, it is possible to prevent the fiber bundle 56 from being easily broken or damaged due to the rotation of the fiber.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 5 shows the overall configuration of the optical tomographic imaging apparatus, and FIG. 6 shows a Nipkow disc. The optical tomographic imaging apparatus 71A shown in FIG.
The low-interference light from the SLD 72 is incident on a half mirror 74 for mixing light via a collimator lens 73, and the light transmitted through the half mirror 74 is condensed by a condenser lens 75 to one end of a single mode fiber 76. Incident.

The other end of the single mode fiber 76 is disposed in the light guide probe 77, and irradiates the subject 79 via an optical scanning mechanism 78 A disposed on the tip side of the light guide probe 77. The reflected light follows the reverse optical path and returns to the half mirror 74 via the single mode fiber 76.

On the other hand, a part of the low interference light from the SLD 72 is reflected by the half mirror 74 and guided by the actuator 82 to the movable reflector 81 as shown by the symbol g.
The light reflected by the reflector 81 and follows the reverse optical path and transmitted through the half mirror 74 is received by the photodetector 83 together with the return light from the single mode fiber 76 side, and is photoelectrically converted.

After the output signal of the photodetector 83 is amplified by the amplifier 84, the signal is input to the image processing section 85, where the signal component that has undergone optical interference is extracted, and the signal data is output to the computer 86.

The computer 86 receives the signal data from the image processing section 85 and receives the signal data via the control device 87.
By driving the drive unit 88 of 8A and the actuator 82,
A process for generating image data is performed. Then, the generated image data is output to the monitor 89, and a tomographic image is displayed on the display surface.

The optical scanning mechanism 78 according to the present embodiment has the following configuration. A collimating lens 91 is disposed to face the distal end surface of the single mode fiber 76, and a Nipkow disk 92 that is rotated and driven by a motor 93 is disposed to face the collimating lens 91. Light passing through the opening 94 of the Nipkow disk 92 is GRIN lens 9
The light is irradiated to the subject 79 side through 5.

As shown in FIG. 6, the Nipkow disc 92 has a small opening 9 formed along a spiral in a disk-shaped light shielding member.
When the Nipkow disk 92 is rotationally driven around its center by a motor 93, the light applied to the Nipkow disk 92 scans through each opening 94 so as to draw a small circular arc, respectively. The whole scans a circular area. In addition, irradiation is performed while scanning a circular area on the subject 79 side via the GRIN lens 95.

According to the present embodiment, a circular area can be optically scanned with low interference light at a higher speed than in a scanning method in which the angle and the like of a scanning mirror is changed by simply driving the Nipkow disk 92 to rotate. Can be.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 7 shows the entire configuration of the optical tomographic imaging apparatus, and FIG. 8 shows a driving mechanism of the scanning mirror. Optical tomographic imaging device 7 shown in FIG.
1B uses an optical scanning mechanism 78B different from the optical scanning mechanism 78A provided for the light guide probe 77 in the optical tomographic imaging apparatus 71A of FIG.

In this embodiment, the light guide probe 77 faces the tip of the single mode fiber
A lens 96 is disposed, and the light is reflected by a scanning mirror 98 disposed between the first and second fixed mirrors 97 a and 97 b via the GRIN lens 96, and is reflected by the GRIN lens 9.
Irradiation is performed on the subject side after passing through Step 5.

The scanning mirror 98 has the codes h, i
Are driven in the direction shown by the arrow, and by this driving, the light irradiated to the subject side can be scanned in the vertical and horizontal directions.

In this embodiment, a joystick 99 is connected to the control device 87. By operating the joystick 99, the scanning direction of the light to be irradiated on the subject side is instructed. The control device 87 drives the scanning mirror 98 via the drive unit 88.

FIG. 8 shows the driving mechanism of the scanning mirror 98. The scanning mirror 98 has a central portion rotatably supported by a support member 101 by a pin 102 in a direction indicated by reference numeral h, and one end thereof is attached to a movable shaft 104 movable vertically by reference numeral j by an actuator 103. ing.

A gear 105 is fixedly provided on the bottom surface of the support member 101. The gear 105 meshes with a gear 107 attached to a rotating shaft of a motor 106. The support member 101 is rotatable in a horizontal plane as indicated by reference numeral i.

According to the present embodiment, by operating the joystick 99, a tomographic image in the direction desired by the operator can be obtained without moving the probe main body. Note that embodiments and the like configured by partially combining the above-described embodiments and the like also belong to the present invention.

[Supplementary Notes] A light guide for illuminating a specific portion of the subject, a solid-state imaging device for observing the specific portion, and an objective optical system are provided, and in an endoscope having an insertion portion that can be inserted into the subject. Irradiating the object with low-interference light and imaging the inside of the object from reflection and scattered light, so that the object is irradiated with the low-interference light and the reflected light reflected from the object is detected. A condensing lens for condensing low-interference light from the light guiding unit on the subject; a scanning unit for scanning light emitted from the condensing lens; and the scanned light. Is arranged between the scanning means and the objective optical system, and coupling means for optically coupling the scanning means and the objective optical system is built in the endoscope, and the low interference Deep side that can be imaged by light An endoscope, wherein the circumference, that the range of the depth of field can be observed in the solid-state imaging device was substantially coincide.

2. In claim 1, a captured image of a specific portion of the subject captured by the solid-state imaging device and an internal image of the subject imaged by the low-interference light are simultaneously generated.
Alternatively, the information is displayed so as to be switchable. 3. Claim 1 is characterized in that the coupling means is a half mirror.

4. Claim 1 is characterized in that the objective optical system includes a zoom mechanism. 5. In claim 1, the solid-state imaging device has a wavelength sensitivity characteristic capable of imaging the low-interference light, and measures the position or shape of a point, a line, or a plane at which the low-interference light is projected onto a characteristic portion of the subject. It is characterized by having means.

6. Claim 5 is characterized in that the measuring means performs the same display so that the positional relationship between the captured image and the internal image of the subject corresponds. 7. Claim 1 is characterized in that the resolution of a captured image of a specific part of the subject imaged by the solid-state imaging device substantially matches the resolution of the internal image of the subject imaged by the low interference light.

8. In claim 1, a step of obtaining a captured image of a specific portion of the subject captured by the solid-state imaging device, a step of enlarging the captured image, and a step of forming a cross-sectional image in the depth direction in the enlarged captured image An endoscope apparatus having a step of displaying a captured image and a cross-sectional image simultaneously or switchably.

9. An elongated insertion portion that can be inserted into the subject, a light source that generates low-interference light, and the low-interference light emitted from the distal end surface of the insertion portion to the subject, and reflected light reflected from the subject. Light guiding means for detecting, interference light extracting means for causing interference between reflected light from the subject and reference light generated from the light source, and extracting an interference signal corresponding to the interfered interference light; A signal processing means for performing signal processing corresponding to the signal, and constructing a cross-sectional image of the subject in the depth direction, the optical tomographic imaging apparatus having a wide angle of view for emitting the low interference light to the subject An optical tomographic imaging apparatus comprising: a lens system; and a circumferential scanning unit configured to transmit the low-interference light through the lens system and scan a subject in a circumferential direction.

10. Claim 9 is characterized in that the circumference scanning means includes a bundle made of a single mode fiber. 11. Claim 9 is characterized in that the circumferential scanning means scans while changing the radius of rotation.

[0092]

As described above, according to the present invention, a light guide for illuminating a specific portion of a subject, an image pickup means provided with an objective optical system for observing the specific portion and a solid-state image sensor. And having an endoscope having an insertion portion that can be inserted into the subject, irradiating the subject with low-interference light,
Reflection, in order to have a means for imaging the inside of the subject from the scattered light, while irradiating the subject with the low interference light, light guide means for detecting the reflected light reflected from the subject,
A condenser lens for condensing low-interference light from the light guide unit on the subject, a scanning unit for scanning light emitted from the condenser lens, and an observation range of the objective optical system for the scanned light. In order to scan inside, the scanning means and the coupling means for optically coupling the scanning means and the objective optical system are incorporated in the endoscope, and the deep side which can be imaged by the low interference light By making the range substantially coincide with the range of the depth of field that can be observed by the imaging unit, the image captured by the imaging unit is blurred if it deviates from the range on the deep side that can be imaged by low interference light. ,
Both images can be easily maintained in a state where they can be clearly observed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an endoscope apparatus provided with a first embodiment of the present invention.

FIG. 2 is a diagram showing an overall configuration of an optical tomographic imaging apparatus.

FIG. 3 is a diagram showing a structure on a distal end side of a probe.

FIG. 4 is a diagram showing a state of optical scanning.

FIG. 5 is a diagram showing an overall configuration of an optical tomographic imaging apparatus.

FIG. 6 is a view showing a Nipkow disc.

FIG. 7 is a diagram showing an overall configuration of an optical tomographic imaging apparatus.

FIG. 8 is a diagram showing a driving mechanism of a scanning mirror.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope apparatus 2 ... Endoscope 3 ... Light source apparatus 4 ... OCT part 5 ... Signal processing part 6 ... Monitor 7 ... Insertion part 8 ... Light guide 11 ... Tip part 13 ... Biological tissue 14 ... Objective optical system 15 ... First lens 16 Zoom lens 17 Half mirror 18 Actuator 19 CCD 21 CCU 22 Scan converter 24 SLD 26, 27 Single mode fiber 32 Mirror 33 Actuator 38, 39 Scurning mirror 41 Photo Diode 43: Image processing device 45: Measurement processing device

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[Procedure amendment]

[Submission date] October 3, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 008

[Correction method] Change

[Correction contents]

2. Appendix 1, wherein a captured image of a specific portion of the subject captured by the solid-state imaging device and a subject internal image imaged by the low interference light are displayed simultaneously or in a switchable manner. . 3. Appendix 1 is characterized in that the coupling means is a half mirror.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0087

[Correction method] Change

[Correction contents]

4. Appendix 1 is characterized in that the objective optical system includes a zoom mechanism . 5 . In Addition 1, the solid-state imaging device has a wavelength sensitivity characteristic capable of imaging the low-interference light, and measures a position or shape of a point, a line, or a plane at which the low-interference light is projected on a characteristic portion of the subject. It is characterized by having means.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0088

[Correction method] Change

[Correction contents]

6. Appendix 5 is characterized in that the measurement means performs the same display so that the positional relationship between the captured image and the image inside the subject corresponds. 7. Appendix 1 is characterized in that the resolution of a captured image of a specific portion of the subject captured by the solid-state imaging device substantially matches the resolution of the subject internal image imaged by the low interference light.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0089

[Correction method] Change

[Correction contents]

8. Appendix 1, wherein a step of obtaining a captured image of a specific portion of the subject captured by the solid-state imaging device;
An endoscope apparatus comprising: a step of enlarging the captured image; a step of forming a cross-sectional image in the depth direction in the enlarged captured image; and a step of displaying the captured image and the cross-sectional image simultaneously or switchably.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0091

[Correction method] Change

[Correction contents]

10. Appendix 9 is characterized in that the circumferential scanning means includes a bundle made of a single mode fiber. 11. Appendix 9 is characterized in that the circumferential scanning means scans while changing the radius of rotation.

Continued on the front page (72) Inventor Hiroyuki Yamamiya 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Industrial Co., Ltd. (72) Inventor Akihiro Horii 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Within Industrial Co., Ltd. (72) Inventor Hitoshi Mizuno 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industrial Co., Ltd. (72) Inventor Jun Hiroya 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Within KOGYO CO., LTD. (72) Katsuichi Imaizumi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Hidemichi Aoki 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Within Optical Industry Co., Ltd. (72) Masahiro Ohno 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. (72) Eiji Yasuda 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. (72) Inventor Yoshimitsu Daimei 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industrial Co., Ltd. (72) Inventor Kenji Yoshino 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industrial Co., Ltd.

Claims (1)

[Claims] 1. A light guide for illuminating a specific part of a subject, a solid-state imaging device for observing the specific part, and an objective optical system are provided, and an insertion part that can be inserted into the subject is provided. The endoscope has a means for irradiating the object with low-interference light and imaging the inside of the object from reflection and scattered light, so that the object is irradiated with the low-interference light and reflected from the object. A light guiding unit for detecting the reflected light, a condensing lens for condensing low-interference light from the light guiding unit on the subject, and a scanning unit for scanning light emitted from the condensing lens. In order to cause the scanned light to scan within the observation range of the objective optical system, a coupling unit disposed between the scanning unit and the objective optical system and optically coupling these components is built in the endoscope. And the image is formed by the low interference light. Endoscopes and scope of the deep side as possible, the range of depth of field that can be observed in the solid-state imaging device is characterized in that so as to substantially coincide.