JP2009018172A - Dental optical diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide non-invasive dental optical diagnostic equipment having a high resolution for solving the problems that there is invasion or indefiniteness in diagnosing by a conventional dental diagnostic apparatus and system by an X-ray image, a visual observation image, probe-palpation, insertion measurement of a pocket probe, a root canal measuring instrument or a Doppler rheometer or the like, a three-dimensional X-ray CT apparatus is large-sized and complicated, and further, while an OCT apparatus acquires an optical tomographic image by reflected light in ophthalmology wherein measurement is easy because an object is soft tissue and the upper surface of a lesion is open, in a dental field, the shape and operability of a detection probe are important in an OCT apparatus for measuring the reflected light because the object is complicatedly constituted of a tooth being hard tissue and a gum part being soft tissue and an oral cavity is narrow. <P>SOLUTION: This dental optical diagnostic apparatus is equipped with a camera for visual observation guide light emitted to a tooth part and visible light for a surface image, a low coherent light emitting means for diagnosis, and an OCT means for scanning the specified region of a surface image by signal light and detecting the reflected light from a predetermined deep part in the region by a probe for the dental optical diagnostic apparatus to acquire an optical tomographic image or the surface image and the optical tomographic image. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a diagnostic apparatus in dental practice,
In particular, the present invention relates to an optical diagnostic apparatus using an OCT (Optical Coherence Tomography) apparatus.

For example, a conventional diagnostic apparatus and method in dental practice are as follows:
[1] The caries detection diagnosis of the adjacent surface is based on an X-ray image or a visual image by lamp irradiation.
[2] Enamel demineralization (initial caries) and calcification diagnosis (judgment of remineralization) by visual inspection, palpation with a dental probe, or measurement of fluorescence with a laser-excited fluorescence meter,
[3] The initial caries of the dentin and the diagnosis of its progress are made by visual inspection, palpation with a dental probe, or measurement of fluorescence with a laser-excited fluorescence measuring instrument.
[4] Diagnosis of the inflamed part of gingiva and its progress is based on X-ray images
[5] Diagnosis of the shape and depth of the periodontal pocket is based on visual and multi-angle X-ray images, and the depth is measured by inserting a pocket probe.
[6] Diagnosis of the hidden part of the tooth in the periodontal pocket is based on visual and multi-angle X-ray images.
[7] Diagnosis of calculus adhesion is visually
[8] Root canal treatment support by imaging the apex of the root canal is measured by X-rays and root canal measurement.
[9] Life / death determination of pulp, identification of pulp inflamed part and diagnosis of progress are made by X-ray or laser Doppler blood flow meter.
[10] The number of roots and their position can be confirmed by three-dimensional X-ray CT.
[11] Diagnosis of cracks and chipping of tooth roots by three-dimensional X-ray CT
Each was going.

However, the diagnosis of each item described above has the following problems. That is,
[1] The X-ray image and the caries detection diagnosis of the adjacent surface by visual observation with lamp irradiation are difficult to understand because the image is unclear,
[2] Palpation with a dental probe, or enamel demineralization (initial caries) and calcification diagnosis (judgment of remineralization) by fluorescence measurement with a laser-excited fluorometer. Visual or palpation However, the possibility of remineralization cannot be determined, and the fluorescence measurement is a numerical result display from 1 to 100, but the range setting of the numerical threshold is not qualitative and lacks reliability.
[3] The initial caries of the dentine and its progress diagnosis by visual inspection, palpation and fluorescence measurement are unclear in visual inspection and palpation, and the fluorescence measurement is a numerical result display from 1 to 100 However, the numerical threshold range setting is not qualitative and lacks reliability.
[4] The diagnosis of the inflamed part of the gingiva by X-ray and its progress could be made only by using the X-ray in the case of the inside.

In the shape diagnosis of periodontal pocket of [5] by visual observation or multi-angle X-ray image and depth diagnosis by insertion of a pocket probe, the shape of the pocket is unclear by visual inspection, and in [6] Diagnosis with multi-angle X-ray images was invasive.
Furthermore, in the depth diagnosis, since the pocket probe is inserted deeply into the affected area, the burden on the patient is large.
[7] The visual diagnosis of calculus adhesion was not reliable because of visual observation, and it was not possible to see where it was invisible in the periodontal pocket.
The support of root canal treatment by imaging the root canal by confirming the root canal measuring instrument and X-ray root filling of [8], the measurement by the root canal length measuring instrument, the real-time imaging during the measurement work is X There was invasion because of the continuous irradiation time of the beam, and the confirmation of root filling by X-rays was also invaded.
[9] X-ray image and laser Doppler blood flow meter for life / death determination of pulp, identification of pulp inflamed area and diagnosis of progress, X-ray is invasive and laser Doppler blood flow meter is expensive equipment .
The confirmation of the number of tooth roots and their positions by three-dimensional X-ray CT in [10] is invasive, and the apparatus is complicated and expensive.
Diagnosis of cracking or chipping of tooth roots by the three-dimensional X-ray CT of [11] is invasive, and the apparatus is complicated and expensive.

Further, conventionally, an example of use of the OCT apparatus for diagnosis in a living body is as follows:
An apparatus for acquiring an optical tomographic image of a tissue to be measured by measuring backscattered light when the tissue to be measured is irradiated with low-coherence light. For example, in ophthalmology, an optical tomographic image of a detailed structure under the fundus retina is used. Used to get.
However, in this case, the measurement target is a soft tissue composed of water, blood, fat, and the like, and the upper surface of the affected part is open to the space, so that the measurement is easy and the apparatus is made early.

On the other hand, in dentistry, the object of measurement is a tooth part, and the tooth part is composed of a hard tissue made of dentin and enamel, the soft tissue of the gingival part, and a tissue around the tooth.
And the space which can be used in the oral cavity where the dentition exists is narrow, and the shape varies greatly between individuals.
Therefore, in the OCT apparatus that measures the reflected light reflected at a predetermined depth of the hard and soft tissues, irradiates the low-coherence light with a suitable wavelength in contact with the affected part of the hard tissue and soft tissue, and reflects the reflected light. The shape of the probe (handpiece) at the end of the apparatus for receiving light and its operability are particularly important.
The present invention provides a non-invasive and high-resolution dental optical diagnostic apparatus that solves the above-described problems.

In view of the above, the present inventors have solved these problems by the following means as a result of intensive experimental research.
(1) A dental photodiagnosis device generates low-coherent light having a wavelength in the range of visible light to normal infrared light for irradiating a tooth of a subject, and uses the low-coherent light as signal light. Means for scanning a selected predetermined area;
OCT means for acquiring an optical tomographic image of the scanning region by interference between reflected light from a predetermined depth in the scanning region and a reference light having a slight frequency difference from the signal light or having undergone phase modulation; A dental optical diagnostic apparatus having a dental handpiece-like diagnostic probe mounted on a portable stand or cart. ,
The configuration of the dental photodiagnostic device is horizontally installed from a main body including an image processing unit, a display unit, and an operation unit of the optical diagnostic device arranged on the stand or the cart, and a pole erected from the main body. A dental optical diagnosis characterized by comprising: a multi-joint arm whose posture can be controlled vertically and horizontally; and the dental handpiece-like diagnostic probe disposed at the tip of the multi-joint arm apparatus.

(2) The dental optical diagnostic apparatus according to (1) above, comprising means for emitting point light as guide light for visual observation in a predetermined region of the tooth portion of the subject.
(3) a dental optical diagnostic apparatus that irradiates illumination light over a wide area of a tooth portion of a subject, and that captures an image of reflected light reflected on the tooth surface of the subject based on the illumination light through an imaging lens; The dental photodiagnosis device according to item (1) or (2), further comprising surface image display means for displaying the imaged surface image of the tooth part.
(4) Display means for displaying a surface image picked up by the means for picking up images, area indicating means for indicating a predetermined area of the image area displayed by the image, and the OCT means based on the indicated area The dental light diagnostic apparatus according to item (3), further comprising means for controlling the emission position by scanning the signal light emission position.

(5) A light source from visible light to ordinary infrared light is provided, and the wavelength of the low coherent light applied to the tooth portion of the subject can be changed by switching the light source as necessary depending on the tissue of the diagnostic site. The dental optical diagnostic apparatus according to any one of (1) to (4), wherein the dental optical diagnostic apparatus is characterized in that it can be performed.
(6) OCT means for acquiring an optical tomographic image of a scanning region or an OCT means for acquiring an optical tomographic image of the surface image and the scanning region, an image processing unit, and a radio in a dental handpiece-like diagnostic probe Any one of (1) to (5) above, wherein the diagnostic image is wirelessly transmitted to a display unit disposed in the independent main body. The dental photodiagnosis device described in 1.

(7) The preceding items (1) to (6), characterized by comprising a linearly polarized low coherent light source, a linearly polarizing plate in the reflected light path from the tooth portion, and means for extracting only the linearly polarized light component. ) Dental optical diagnostic apparatus according to any one of the above.
(8) A quarter-wave plate that is arranged in a light source optical path of linearly polarized low-coherent light, and that linearly polarized light is circularly polarized light, and a polarizing beam splitter that divides the circularly polarized light into linearly polarized light that is orthogonal to each other. A quarter-wave plate disposed in a reference optical path and having linearly polarized light from the polarizing beam splitter as circularly polarized light,
A quarter-wave plate disposed in a reflection optical path and having linearly polarized light from the polarizing beam splitter as circularly polarized light, and a linear polarizing plate disposed in proximity to the quarter-wave plate, The dental optical diagnostic apparatus according to any one of (1) to (7) above, comprising means for extracting only the linearly polarized light component.

According to the present invention, the following excellent effects can be exhibited.
1. According to the invention of claim 1 of the present invention,
A means for generating low-coherent light having a wavelength in the range from visible light to normal infrared light for irradiating the tooth portion of the subject;
Means for scanning a selected predetermined region of the tooth portion using the low coherent light as signal light;
Reflected light from a predetermined depth in the scanning region;
OCT means for acquiring an optical tomographic image of the scanning region by interference with reference light,
The tip is a stand-alone type in which a dental optical diagnostic apparatus equipped with a dental handpiece-like diagnostic probe is mounted on a portable stand or cart;
The configuration of the dental optical diagnostic apparatus is as follows:
A main body having an image processing unit, a display unit, and an operation unit of an optical diagnostic apparatus disposed on the stand or cart, and a multi-joint capable of posture control up and down and left and right provided from a pole erected from the main body Arm,
Since it comprises the dental handpiece-like diagnostic probe disposed at the tip of the articulated arm,
In order to scan the tooth part of the subject with signal light, it consists of hard tissue teeth made of dentin, enamel, etc., soft tissue made of gingiva, etc., and a periodontium in which the hard tissue and soft tissue are intricately interlaced Unlike various types of diagnostic apparatuses mainly using conventional X-rays, it is possible to provide a non-invasive and high-resolution diagnostic apparatus.
In addition, it is possible to easily diagnose the tooth portion in the oral cavity where the usable space is narrow and the shape varies greatly between individuals.
Furthermore, the device can be easily moved to the optimal position near the patient, and the measurement window at the tip of the diagnostic probe is controlled by the posture control by the articulated arm and the rotating part of the probe. Since the diagnostic probe is not shaken, a stable optical tomographic image can be obtained.

2. According to the invention of claim 2,
Since a means for emitting point light as a guide light for visual observation is provided in a predetermined region of the subject's tooth portion, the practitioner attaches a dental handpiece-like diagnostic probe to the subject's tooth portion. Can easily come into contact.
3. According to the invention of claim 3,
Means for irradiating illumination light over a wide area of the tooth portion of the subject, and imaging an image of reflected light reflected on the tooth surface of the subject based on the illumination light through an imaging lens;
Since it comprises surface image display means for displaying the surface image of the imaged tooth part,
While observing the surface image, a depth-resolved optical tomographic image of the tooth can be acquired, and the diagnosis of the tooth tissue can be easily performed.

4. According to the invention of claim 4,
Display means for displaying a surface image picked up by the image pickup means;
Among the image areas displayed by the image, there are provided area indicating means for indicating a predetermined area, and means for controlling the emission position by scanning the signal light emission position by the OCT means based on the indicated area. The optical tomographic image can be acquired, and the tooth tissue can be diagnosed with high accuracy.
5. According to the invention of claim 5,
It has a light source from visible light to normal infrared,
The wavelength of the low coherent light applied to the tooth part of the subject,
Because it can be changed by switching the light source as necessary due to the difference in the tissue of the diagnostic site,
It is possible to accurately diagnose a tooth portion having a complex tissue by changing the wavelength of irradiation light in accordance with the diagnosis region.

6. According to the invention of claim 6,
OCT means for acquiring an optical tomographic image of a scanning region or an OCT means for acquiring an optical tomographic image of the surface image and the scanning region, an image processing unit, and wireless image transmission in a dental handpiece-like diagnostic probe With means,
The diagnostic image is wirelessly transmitted to a display unit disposed on the independent main body.
For example, the optical diagnostic probe is a short gun type, and an amplifier, a demodulator, an A / D converter, a computer and a wireless transmitter are housed in the handle in the handle, and image information created in the computer is Sent by a wireless transmitter. And it displays on the display part of the receiver which has the antenna installed in the required place of the vicinity.
As described above, the dental optical diagnostic apparatus can be further downsized and simplified.
7. According to the invention of claim 7,
A low-coherent light source that is linearly polarized, and a linearly polarizing plate in the reflected light path from the teeth,
Since it has a means to extract only the linearly polarized light component,
By removing the reflected light wave from the part off the linear position of the incident light wave, the background noise can be reduced and the resolution can be increased. A tomographic image can be obtained.

8. According to the invention of claim 8,
A quarter-wave plate disposed in the light source optical path of the linearly polarized low-coherent light and having the linearly polarized light as circularly polarized light;
A polarization beam splitter that divides the circularly polarized light into two linearly polarized lights orthogonal to each other;
A quarter-wave plate disposed in a reference optical path, wherein the linearly polarized light from the polarizing beam splitter is circularly polarized light;
A quarter-wave plate disposed in a reflection optical path and having linearly polarized light from the polarizing beam splitter as circularly polarized light;
A linearly polarizing plate disposed close to the quarter-wave plate,
Since it has a means to extract only the linearly polarized light component,
Optical loss along the way can be minimized, and the linearly polarized light parallel to each other can be detected and interfered with the multiple reflected light waves and the reference wave very efficiently, with high signal resolution and good signal-to-noise ratio. A high-quality optical tomographic image can be obtained.

By using the OCT apparatus in dental practice, a dental diagnostic apparatus that is non-invasive and has high resolution can be obtained unlike an X-ray apparatus that is a conventional main diagnostic means.
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an external perspective view of an independent dental optical diagnostic apparatus equipped with a diagnostic probe at the tip of an articulated arm mounted on a cart of the present invention.
In the figure, 1 is an optical diagnostic device, 2 is a main body, 3 is an operation unit, 4 is an operation switch, 5 is a display unit, 6 is a pole, 7 is an articulated arm, 8 is a pivoting portion at the end of the arm, and 9 is a diagnosis. The probe for probe 10 is a rotating part of the probe, 11 is the tip of the probe, 12 is a window for measurement, 13 is a foot switch, and 14 is a caster.

The dental optical diagnostic apparatus 1 includes an image processing unit (described later) including a light source, an optical system circuit, a mechanism, detection and demodulation of signal light, an imaging circuit, a display circuit, a region specifying circuit, and the like. It has a main body 2 that is housed, and an operation unit 3 (described later) having an operation switch 4 on the panel above it.
In addition, a pole 6 erected above the operation unit 3, a display unit 5 that matches the position of the line of sight disposed on the pole 6, and an articulated arm 7 that is installed horizontally from the tip of the pole 6. With
The pivoting portion 8 at the distal end of the articulated arm 7 has a pivoting portion 10 for the probe at the base, and a measurement window 12 is provided at the distal end portion 11 of the probe. And a dental diagnostic probe 9 having an OCT optical system (described later) for acquiring an optical tomographic image.
The measurement window 12 at the distal end portion 11 of the diagnostic probe 9 is placed at a predetermined position by controlling the posture of the affected part (not shown) of the tooth portion of the subject by the articulated arm 7 and the probe rotating unit 10. Since the diagnostic probe 9 is not shaken, a stable wide-field surface image and a small-area optical tomographic image can be obtained.

However, when it is not necessary to capture a surface image, the optical system is also unnecessary.
And when irradiating a point-shaped guide light (visible light) for the operator to make the diagnostic probe contact the target location of the tooth part visually,
For example, an irradiation mechanism including a guide light source (83: red or green is desirable), a lens (84) for focusing the beam, and the probe measurement window 12 is required.
Further, a hands-free operation can be performed by the foot switch 13, and the main body 2 can be installed at an optimum position for diagnosis by the caster 14.
Further, the display unit 5 may be a touch panel, and the operation unit 3 may be omitted (not shown).

FIG. 5 is a block diagram illustrating the configuration of the optical fiber type dental optical diagnostic apparatus of the present invention.
FIG. 6 is a block diagram for explaining the configuration of the optical fiber type dental optical diagnostic apparatus having the surface image capturing means of the present invention.
In the case of FIG. 6, the surface image obtained by the camera and the OCT unit scan the position of the reference mirror to obtain a one-dimensional reflected light profile, and further scan the light beam in the two-dimensional direction. The optical tomographic image is obtained, and both are displayed to facilitate diagnosis.
In the figure, 30 is a light source unit, 31 is signal light, 32 is SLD (super luminescent diode), 33 is a mode-locked laser (forsterite), 34 is an optical fiber, 35 is an optical fiber coupling unit, 36 is an optical fiber coupler, 37 Is a reference mirror scanning unit, 38 is a reference beam, 39 is a lens, 40 is a reflecting mirror, 41 is a transducer, 42 is a moving stage, 43 is a depth direction scan, 44 is a signal processing unit, 45 is a detector, 46 is Amplifier, 47 Demodulator, 48 A / D converter, 49 Image processing / scanning control unit, 50 Computer, 51 Storage device, 52 LAN connection, 53 Printer, 54 Display unit, 55 Surface Image, 56 is an optical tomographic image, 57 is a measurement pattern, 58 is measurement data, 59 is a signal line, 60 is a motor, 61 is a coupling, 62 is a nut, 63 Ball screw, 64 slide rail, 65 surface plate, 67 lens, 68 white light source, 69 surface imaging camera, 70 beam splitter, 71 white light path, 72 signal light light path, 73 teeth, Reference numeral 74 denotes teeth, 75 denotes gums, and 76 denotes a region designation marker.

As shown in the figure, first, the white light source 68 in the optical diagnostic probe 9 is transmitted through the beam splitter 70 from the front periphery of the surface image capturing camera 69 through the optical fiber 34, and the tooth portion of the subject as in the white light path 71. A surface image of a wide area is obtained by the surface image capturing camera 69. This image is stored in the storage device 51 of the computer 50 and displayed as an observation image on the display portion of the surface image 55 of the monitor of the display portion 54 by the operation of the computer 50.
In addition, an area designation marker 76 for designating the display area of the optical tomographic image 56 in the surface image 55 is displayed on the monitor.
Next, the acquisition of the optical tomographic image 56 is performed by switching, for example, the SLD 32 or the mode-locked laser: Cr ^-4+ : Mg ₂ SiO ₄ (forsterite) 33 having a different wavelength region as a light source of low-coherent light, It generates light with a wavelength in the range from visible light to ordinary infrared light.

At this time, when the wavelength of light is greatly changed, it is exchanged with an optical fiber corresponding to a required wavelength, or an optical system based on two types or various types of optical fibers is arranged in parallel so as to be switched ( Not shown).
The low-coherent light (signal light 31) passes through the optical fiber 34 of the optical fiber coupling portion 35, passes through the optical fiber coupler 36, and is further expanded by the optical fiber 34 so that the lens in the optical diagnostic probe 9 is used. The optical diagnostic probe at the position of the region designation marker 76 of the optical tomographic image 56 in the surface image 55 displayed on the monitor of the display unit 54 after being focused and reflected by 90 ° by the beam splitter 70. 9 is moved and focused on a predetermined diagnosis region of the tooth portion 73 like a signal light optical path 72.

Further, the light reflected from the predetermined depth of the tooth portion reaches the optical fiber coupler 36 through the reverse path to the above, and is sent to the detector 45 of the signal processing unit 44 through the optical fiber 34. The reference light that has been subjected to the signal light and the phase modulation is operated by moving the moving stage 42 by the reflecting mirror 40 and the vibrator 41 in the depth direction.
The signal light 31 and the reference light 38 are combined by the optical fiber coupler 36 and interfere with each other.
This interference signal is displayed on the monitor as an optical tomographic image 56 of a predetermined area by the amplifier 46, demodulator 47, A / D converter 48, and computer 50.

The measurement pattern at the bottom of the monitor is, for example, a profile of reflected light in the optical axis direction obtained by plotting the magnitude of the optical interference signal detected at each optical path length with the scanning in the depth direction as the horizontal axis. Yes,
The optical tomographic image 56 is an image of a two-dimensional optical image obtained by lateral scanning of incident light.
Furthermore, if the measurement data 58 is displayed on the monitor and stored in the storage device 51 together with the respective images, the diagnostic record can be reproduced when necessary.
However, when it is not necessary to capture a surface image, the optical system is also unnecessary as shown in FIG.
And when irradiating the point-shaped guide light (visible light) for the operator to make the diagnostic probe 9 come into contact with the target portion of the tooth portion visually,
For example, an irradiation mechanism including a guide light source (83: red or green is desirable), a lens 67 (also used) for focusing the beam, and the probe measurement window 12 is required.

FIG. 7 is a block diagram illustrating the configuration of the spatial propagation type dental optical diagnostic apparatus of the present invention.
FIG. 8 is a block diagram for explaining the configuration of the space propagation type dental optical diagnostic apparatus having the surface image capturing means of the present invention.
This case is also called a bulk type.
As an outline, a parallel light beam is irradiated on the tooth part of the subject, and signal light is processed in parallel for each pixel by a detector such as a CCD or CMOS in which pixels are arranged in two dimensions, It is effective to speed up the diagnosis time.
In FIG. 8, 77 is a right-angle prism, 78 is a lens, 79 is a white light / signal light optical path, 80 is a detector, and 81 is an optical path.
As shown in the figure, first, the white light source 68 (for example, LED) in the optical diagnostic probe 9 passes through the beam splitter 70 ′ from the front periphery of the surface image capturing camera 69, as in the white light path / signal light light path 79. A tooth image 73 of the subject is irradiated and a surface image of a wide area is obtained by the surface image capturing camera 69.

This image is stored in the storage device 51 of the computer 50 and displayed as a surface image on the display portion of the surface image 55 of the monitor of the display portion 54 by the operation of the computer 50.
Further, an area designation marker 76 for designating the display area of the optical tomographic image 56 in the surface image is displayed on the monitor.
The optical tomographic image 56 is acquired by switching, for example, the SLD 32 or the mode-locked laser: Cr ^-4+ : Mg ₂ SiO ₄ (forsterite) 33 (not shown) having a different wavelength range as a light source of low coherent light. Thus, light having a wavelength in the range of visible light to ordinary infrared light is generated.
The low-coherent light (signal light 31) is incident on the beam splitter 70 as parallel light having a predetermined area by the lens 78.

Then, the signal light 31 reaches the beam splitter 70 ′ like the optical path 81, is reflected by 90 °, passes through the white light / signal light optical path 79, and irradiates a predetermined diagnostic region of the tooth portion 73. Reflected from depth.
In this case, since the irradiation area is not a point but two-dimensional, scanning in the horizontal direction can be omitted.
On the other hand, the optical path of the reference beam 38 is bent by 90 ° by the beam splitter 70, further bent by 90 ° by the right-angle prism 77, phase-modulated by the reflection mirror 40 and the vibrator 41, and reflected to be reflected by the right-angle prism 77. Then, it returns to the beam splitter 70.
The reflected light reaches the beam splitter 70 through a path reverse to the above, mixes and interferes with the reference light, and is transmitted to the detector 80 of the signal processing unit 44 through the imaging lens 78 ′.
Then, the signal light 31 and the reference light 38 are combined and interfered by the beam splitter 70, and this interference light is amplified by an amplifier 46, a demodulator 47, an A / D converter 48, and a computer 50. 56 is displayed on the monitor.

  In this example, the optical tomographic image 56 of the tooth part 73 that has been depth-resolved can be obtained in real time while observing the surface image 55 with the surface image capturing camera 69, so that the development of the three-dimensional image and the tissue Dynamic diagnosis can be achieved.

In addition, the measurement pattern 57 below the monitor has, for example, scanning in the depth direction as a horizontal axis,
The profile of the reflected light on the optical axis direction obtained by plotting the magnitude of the optical interference signal detected on each optical path,
The optical tomographic image 56 is an image of a two-dimensional optical image, and an image of a wide area can be displayed in a short time.
Furthermore, if the measurement data 58 is displayed on the monitor and stored in the storage device 51 together with the respective images, the diagnostic record can be reproduced when necessary.
However, when it is not necessary to capture a surface image, the optical system is also unnecessary as shown in FIG.
And, when irradiating the point-shaped guide light (visible light) for the practitioner to visually contact the target portion of the tooth part, as shown in FIG.
For example, an irradiation mechanism including a guide light source 83 (preferably red or green), a lens 84 for focusing the beam, and the probe measurement window 12 is required.

And as another example, the basic principle is the same as the configuration explanation block diagram of the spatial propagation type dental optical diagnostic device described above,
In the configuration, for example, the optical diagnostic probe is a pistol type, and the amplifier 46, the demodulator 47, the A / D converter 48, the computer 50, and the wireless transmitter in the subsequent stage of the detector 80 in FIG. The image information stored and generated in the computer 50 may be sent out by a wireless transmitter and displayed on a display unit of a receiver having an antenna installed at a required location in the vicinity (not shown).
As described above, the dental optical diagnostic apparatus can be further downsized and simplified.

Next, an example of a spatial propagation type dental optical diagnostic apparatus provided with linear polarization means will be described.
FIG. 9 is a block diagram of a space propagation type dental optical diagnostic apparatus provided with a linear polarizing plate.
In the figure, 85 indicates a linearly polarizing plate.
The linear polarizing plate 85 is disposed in the multiple reflection optical path 81 between the beam splitter 70 and the tooth portion 73, and only the linearly polarized light component from the tooth portion 73 is obtained even when the low-coherent light wave is linearly polarized. Can be extracted and detected.
The secondary reflected light wave from the fine indefinite shape surface at the tooth portion 73 does not show clear polarization and depolarizes, but the primary reflected light wave of the incident light wave reflects the polarization.
Therefore, by arranging the linearly polarizing plate 85 in the multiple reflection optical path 81 between the beam splitter 70 and the tooth portion 73 and extracting only the linearly polarized light component, the background noise can be reduced and the resolution can be increased. The optical tomographic image 56 can be obtained with high resolution and a good signal-to-noise ratio with respect to the tooth portion 73.

FIG. 10 is a block diagram of a spatial propagation type dental optical diagnostic apparatus including a linearly polarizing plate, a quarter-wave plate, and a polarizing beam splitter.
In the figure, 86 is a quarter wave plate, and 87 is a polarizing beam splitter.
The beam splitter 70 shown in FIG.
A quarter-wave plate 86 is disposed between the polarizing beam splitter 87 and the linear polarizing plate 85, between the polarizing beam splitter 87 and the right-angle prism 77, and between the polarizing beam splitter 87 and the lens 78, respectively. It is a thing.
In the low-coherent light source optical path, the linearly polarized light output from the SLD 32 of the light emitting element is transmitted through the quarter-wave plate 86 as circularly polarized light, and is divided into two orthogonally polarized light using the polarization beam splitter 87. .
Of these, the linearly polarized light component in one reference optical path is transmitted through the quarter-wave plate 86, is reflected by the reference mirror (reflection mirror 40 and vibrator 41) through the right-angle prism 77,
The polarized light transmitted through the quarter-wave plate 86 again through the reverse path is transmitted through the polarization beam splitter 87 and guided to the detector 80.

Further, the linearly polarized light in the other reflected light path is transmitted through the quarter-wave plate 86 and the linearly polarizing plate 85 and is applied to the tooth portion 73.
The multiple reflected light waves from the tooth portion 73 are converted into linearly polarized light by an appropriate combination of angles of the linearly polarizing plate 85 and the quarter-wave plate 86 and guided to the detector 80 via the polarizing beam splitter 87.
As a result, optical loss along the way can be minimized, and the multiple reflected light wave and the reference wave interfere with each other and are detected as linearly polarized light parallel to each other.
The present invention can be variously modified in addition to the above embodiments.

1 is an external perspective view of a stand-alone dental optical diagnostic apparatus equipped with a diagnostic probe at the tip of an articulated arm mounted on a cart of the present invention. 1 is a block diagram illustrating the configuration of an optical fiber type dental optical diagnostic apparatus according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating a configuration of an optical fiber type dental optical diagnostic apparatus having a surface image capturing means of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating a configuration of a space propagation type dental optical diagnostic apparatus according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating a configuration of a space propagation type dental optical diagnostic apparatus having a surface image capturing means of the present invention. The block diagram of the space propagation type dental optical diagnostic apparatus provided with the linearly-polarizing plate. The block diagram of the spatial propagation type dental optical diagnostic apparatus provided with the linearly-polarizing plate, the quarter wave plate, and the polarizing beam splitter.

Explanation of symbols

1: Optical diagnostic device 2: Main body 3: Operation unit 4: Operation switch 5: Display unit 6: Pole 6 ': Probe and light pole 7: Articulated arm 8: Arm tip turning unit 9: Diagnosis probe 10 : Probe rotating part 11: Probe tip part 12: Measurement window 13: Foot switch 14: Caster 30: Light source part 31: Signal light 32: SLD
33: mode-locked laser 34: optical fiber 35: optical fiber coupling unit 36: optical fiber coupler 37: reference mirror scanning unit 38: reference light 39: lens 40: reflection mirror 41: vibrator 42: moving stage 43: depth direction Scanning 44: Signal processing unit 45: Detector 46: Amplifier 47: Demodulator 48: A / D converter 49: Image processing / scanning control unit 50: Computer 51: Storage device 52: LAN connection 53: Printer 54: Display unit 55: surface image 56: optical tomographic image 57: measurement pattern 58: measurement data 59: signal line 60: motor 61: coupling 62: nut 63: ball screw 64: slide rail 65: surface plate 66: moving stage 67: lens 68 : White light source 69: Surface image capturing camera 70, 70 ′: Beam splitter 71: White light path 72: Signal light path 73: Tooth part 74: Tooth 75: Gingival 76: Area designation marker 77: Right angle prism 78: Lens 78 ': Imaging lens 79: White light / signal light optical path 80: Detector 81: Optical path 82: Horizontal scanning 83: Guide light source 84: Lens 85: Linearly polarizing plate 86: Quarter wavelength plate 87: Polarizing beam splitter

Claims (8)

A means for generating low-coherent light having a wavelength in a range from visible light to normal infrared light for irradiating a dental part of a subject with a dental optical diagnostic device;
Means for scanning a selected predetermined region of the tooth portion using the low coherent light as signal light;
Reflected light from a predetermined depth in the scanning region;
OCT means for acquiring an optical tomographic image of the scanning region by interference with a reference light having a slight frequency difference or phase modulation from the signal light. In
The tip is a stand-alone type in which a dental optical diagnostic apparatus equipped with a dental handpiece-like diagnostic probe is mounted on a portable stand or cart;
The configuration of the dental optical diagnostic apparatus is as follows:
A main body including an image processing unit, a display unit, and an operation unit of an optical diagnostic apparatus disposed on the stand or cart;
An articulated arm that can be posture-controlled in the vertical and horizontal directions from a pole erected from the main body;
The dental handpiece-like diagnostic probe disposed at the tip of the articulated arm;
A dental photodiagnostic device characterized by comprising:   2. The dental optical diagnostic apparatus according to claim 1, further comprising means for emitting point light as guide light for visual observation in a predetermined region of the tooth portion of the subject. Means for irradiating illumination light over a wide area of the tooth portion of the subject, and imaging an image of reflected light reflected on the tooth surface of the subject based on the illumination light through an imaging lens;
Display means for displaying a surface image of the imaged tooth part;
A means for generating predetermined low-coherent light having a wavelength in a range from visible light to normal infrared light for irradiating the tooth portion of the subject;
Means for scanning a selected predetermined region of the tooth portion using the low coherent light as signal light;
OCT means for acquiring an optical tomographic image of the scanning region by interference between reflected light from a predetermined depth in the scanning region and reference light having a slight frequency difference from the signal light or having phase modulation The dental photodiagnosis device according to claim 1, wherein the dental photodiagnosis device is provided. Display means for displaying a surface image picked up by the image pickup means;
Of the image area displayed by the image, an area indicating means for indicating a predetermined area, and based on the indicated area, signal light emission position scanning by the OCT means,
The dental optical diagnostic apparatus according to claim 3, further comprising means for controlling an injection position. It has a light source from visible light to normal infrared,
The wavelength of the low coherent light applied to the tooth part of the subject,
The dental optical diagnostic apparatus according to any one of claims 1 to 4, wherein the dental optical diagnostic apparatus according to any one of claims 1 to 4, wherein a change can be made by switching a light source according to a difference in a tissue of a diagnostic part. OCT means for acquiring an optical tomographic image of a scanning region or an OCT means for acquiring an optical tomographic image of the surface image and the scanning region, an image processing unit, and wireless image transmission in a dental handpiece-like diagnostic probe With means,
The dental optical diagnostic apparatus according to any one of claims 1 to 5, wherein the diagnostic image is wirelessly transmitted to a display unit disposed in the independent main body. A linearly polarized low coherent light source;
A linear polarizing plate is provided in the optical path reflected from the tooth,
The dental optical diagnostic apparatus according to any one of claims 1 to 6, further comprising means for extracting only a linearly polarized light component. A quarter-wave plate disposed in the light source optical path of the linearly polarized low-coherent light and having the linearly polarized light as circularly polarized light;
A polarization beam splitter that divides the circularly polarized light into two linearly polarized lights orthogonal to each other;
A quarter-wave plate disposed in a reference optical path, wherein the linearly polarized light from the polarizing beam splitter is circularly polarized light;
A quarter-wave plate disposed in a reflection optical path and having linearly polarized light from the polarizing beam splitter as circularly polarized light;
A linearly polarizing plate disposed close to the quarter-wave plate,
The dental optical diagnostic apparatus according to any one of claims 1 to 7, further comprising means for extracting only a linearly polarized light component.

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