JP2004298503A - Optical imaging apparatus for dental checkup - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical imaging apparatus for dental checkup to be inserted into an oral cavity, which realizes a cell-based dental checkup. <P>SOLUTION: A two-dimensional scanner 18 scans light from a light source 14 on a proximal end face of a fiber optic bundle 6 threading a light scanning probe 3 provided with an elongate inserting part 7 or the like. A condenser 21 condenses the light, which is to be incident on a fiber optics 6a at a focus position and transmitted to be emitted from a distal end face of a distal end part 11 inserted in an oral cavity 2 on a target region side such as a gingival part or the like behind a tooth 2a. The light reflected and scattered on the target region side is to be incident on the fiber optics 6a and trace back the light path used upon entering, part of which is reflected by a beam splitter 17, received at a light detector 26, photoelectrically converted, amplified and others at a signal processing circuit, and then, two-dimensionally image-processed by a personal computer 28 so that an image with a cell-based resolution can be displayed on a displaying face of a monitor 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical imaging device for dental inspection that performs a dental inspection using a confocal optical system.
[0002]
[Prior art]
As a first conventional example, there is US Pat. No. 6,179,611 B1. This conventional example discloses an OCDR (Optical Coherence Domain Reflectometry) technique for dental examination.
[0003]
As a second conventional example, there is a confocal microscope for oral examination described in the following non-patent document. This confocal microscope discloses that the probe part is large, so that the tissue of the tongue and the outside of the teeth, which can be taken out of the oral cavity, can be examined at the cell level using a confocal optical system.
[0004]
[Patent Document 1]
US Pat. No. 6,179,611 B1
[0005]
[Non-patent document 1]
W. Matthew White, "Noninvasive Imaging of Human Oral Mucosa in Vivo by Confocal Reflectance Microscopy", Laryngoscope 109: October 1991, October 17, 1999
[0006]
[Problems to be solved by the invention]
In the OCDR and OCT as in the first conventional example, there is a limit in resolution. That is, it is difficult to obtain cell-level accuracy as in a confocal microscope. Therefore, the ability of diagnosis is also limited.
Further, in the first conventional example, since only one-dimensional scanning is performed, a two-dimensional image cannot be obtained, so that there is a disadvantage that diagnosis is difficult.
[0007]
On the other hand, in the second conventional example, the test can be performed at the cell level, but it is difficult to insert into the oral cavity because the probe portion is large, so that it is difficult for a dental test. In particular, there is a disadvantage that dental examinations such as gingival examination on the back side of the teeth, which are indispensable for examination of caries and periodontal disease, cannot be performed.
[0008]
(Object of the invention)
The present invention has been made in view of the above points, and an object of the present invention is to provide an optical imaging apparatus for dental examination that can be inserted into an oral cavity and can perform dental examination at a cellular level.
[0009]
[Means for Solving the Problems]
A light source for generating light,
A light guide for transmitting and receiving the light to the subject,
Holding the light guide, a handheld probe unit that can be inserted into the oral cavity,
A confocal optical system capable of satisfying the light in a confocal condition,
Scanning means for scanning the subject with the light,
Light detection means for detecting the reflected and scattered light reflected and scattered from the subject,
An image generation unit that processes a signal detected by the light detection unit and generates a tomographic image of the subject,
Is provided so that the distal end side of the handheld probe unit is inserted into the oral cavity so that dental examination can be performed at the cellular level.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First Embodiment)
FIG. 1 shows an optical imaging apparatus 1 for dental inspection according to a first embodiment of the present invention. The optical imaging apparatus 1 for dental inspection is inserted into the oral cavity 2, and the optical scanning probe 3 that scans light on the inspection site side, and the optical scanning probe 3 is detachably connected. An optical imaging device main body (hereinafter simply referred to as the device main body) 4 for supplying and supplying the light returned from the inspection site by the optical scanning probe 3 to form an image, and a video signal from the device main body 4 And a monitor 5 for displaying as an imaging image.
[0011]
The optical scanning probe 3 has an elongated and hard insertion portion into which an optical fiber bundle 6 as an optical guide means for transmitting light to the subject side and transmitting return light from the subject side to the light detection means side is inserted. And an optical fiber bundle 6 provided at the rear end of the insertion portion 7 and held by an operator by a hand, and extended rearward from the handheld portion 8. A connector 9 provided at the rear end is detachably fixed to the apparatus main body 4.
[0012]
Further, the insertion portion 7 has a tip portion 11 formed at the tip thereof, which performs two-dimensional optical scanning on the test site side and receives return light reflected or scattered on the test site side, 11 is provided with a bent portion 12 which is bent (curved) by about 90 degrees in the vicinity of the rear end, and since the bent portion 12 is provided, when the distal end surface of the distal end portion 11 is inserted into the oral cavity 2, the oral cavity 2 By contacting the lower or upper teeth 2a or the gingival portion (on the back side or the like) of the base end thereof, it is possible to easily set an observation image.
[0013]
Further, a light source 14 such as a semiconductor laser for generating light is provided in the apparatus body 4, and the light from the light source 14 is condensed by a condensing lens 15a and provided at a condensing point (of a light shielding plate). The light passes through the pinhole 16 and is further condensed by the condensing lens 15b into a parallel light flux.
[0014]
This parallel light beam passes through a beam splitter 17 such as a half mirror, and is scanned two-dimensionally by a movable mirror 19 of a two-dimensional scanner 18 arranged on the optical path.
[0015]
That is, the movable mirror 19 is connected to driving means (not shown) in two orthogonal directions, the driving means is driven by a driving signal from the scanner driving circuit 20, and the movable mirror 19 connected to the driving means is tilted two-dimensionally. You.
[0016]
Specifically, FIG. 1 shows the movable mirror 19 in a neutral state that is not driven. In the XYZ coordinate system shown in FIG. 1, for example, the movable mirror 19 is moved around the Y axis as shown by an arrow A. By tilting, the reflected light scans the light in the X-axis direction, and the movable mirror 19 is tilted about an axis on the plane of the paper (in this case, the movable mirror 19 is moved perpendicularly to the plane of the paper). The reflected light is scanned in the Y direction by tilting about the direction so as to deviate from the direction, which is indicated by reference numeral B).
[0017]
A condensing lens 21 having a large diameter and a short focal length is disposed on the optical path reflected by the movable mirror 19, and the optical fiber bundle 6 of the optical scanning probe 3 is located at the focal plane of the condensing lens 21. The connector 9 is fixed so that the base end surface of the connector 9 is positioned.
[0018]
That is, as shown in the enlarged view, the connector 9 is inserted so as to fit into the connector receiver 22 of the apparatus main body 4, is positioned in the axial direction at the step portion, and is further finely adjusted. Fixed.
[0019]
In this case, the rear end (base end) of the optical fibers 6 a forming the optical fiber bundle 6 is fixed in a base member forming the connector 9 in a bundled state. The optical fiber 6a is formed by, for example, bundling optical fibers having a diameter of several microns or less two-dimensionally, for example, about 10,000 to 50,000. In this case, the bundled shape may be a square, a rectangle, or a circle.
[0020]
By positioning and fixing the connector 9 provided at the base end of the optical fiber bundle 6 formed by bundling a large number of optical fibers to the connector receiver 22, the base end surface of the optical fiber bundle 6 is arranged on the XY plane. When the movable mirror 19 is tilted and scanned as described above, the light reflected by the movable mirror 19 scans the base end surface of the optical fiber bundle 6 on the XY plane two-dimensionally, and the optical fibers 6a Are sequentially incident at a constant period.
[0021]
In this case, the two-dimensional tilt of the movable mirror 19 causes the focal position condensed by the condenser lens 21 to move two-dimensionally on the focal plane, and is positioned and arranged on the focal plane by this movement. Light is sequentially incident on each optical fiber 6a in the optical fiber bundle 6. The optical fiber 6a on which the light is incident is transmitted to the distal end side by the optical fiber 6a, and is emitted from the distal end surface.
[0022]
In this case, as shown in the enlarged view of the distal end portion 11 of the probe 3, an optical fiber 6a constituting the optical fiber bundle 6 is fixed to a hole of the distal end member. In the present embodiment, a microlens 23 is integrally attached to the distal end surface of each optical fiber 6a, and collects and emits light toward the inspection site.
[0023]
The front of the microlens 23 is covered with a cover glass 24, and the inside thereof has a watertight structure so that the microlens 23 can be easily washed and disinfected with washing water and a disinfectant.
The light emitted to the inspection site side via the cover glass 24 is reflected or scattered by a tissue or the like near the surface of the inspection site side, and a part of the light is also incident on the optical fiber 6a that emitted the light.
[0024]
The light incident on the optical fiber 6a is emitted from the base end face thereof, condensed by a condenser lens 21, reflected by a movable mirror 19, and then incident on a beam splitter 17, and a part thereof is reflected and collected. The light is guided to the optical lens 25.
A light detector 26 such as a photodiode is attached to the focal plane of the condenser lens 25. In this case, a pinhole-shaped light receiving portion is formed in the photodetector 26, and only the light condensed at the focal position of the condenser lens 25 is received by the pinhole-shaped light receiving portion. Is not received by the photodetector 26 (or is not incident on the light receiving unit).
[0025]
In other words, only the light guided by the optical fiber 6a used as light and serving as the focal position of the condenser lens 21 in the optical fiber bundle 6 and used for reflected light detection is received by the photodetector 26. Like that.
The signal photoelectrically converted by the photodetector 26 is input to a signal processing circuit 27, where the signal is amplified, A / D converted, and input to a personal computer (hereinafter abbreviated as PC) 28.
[0026]
The PC 28 temporarily stores the input signal data in a memory, a hard disk, or the like, and further, the CPU performs signal processing for forming an image, sends the signal to a video memory, and the image data stored in the video memory is output to the monitor 5, An image obtained by optical scanning by the optical scanning probe 3 is displayed on the display screen.
The PC 28 is connected to the scanner drive circuit 20, controls the operation of the scanner drive circuit 20, and performs an imaging process in synchronization with the scanner drive signal.
[0027]
In the optical imaging apparatus 1 for dental inspection having such a configuration, the optical scanning probe 3 is formed by an optical fiber bundle 6 in which a number of optical fibers 6a for obtaining a two-dimensional image are bundled. In the connector 9, the base end of each optical fiber 6a is arranged on the focal plane of the condensing lens 21 forming the confocal optical system, and the two-dimensional scanner 18 tilts and scans to move the focal position to the focal position. In addition to controlling the light to be sequentially incident on the optical fiber 6a, the light incident on the optical fiber 6a from the inspection site is focused on only the light that satisfies the condition of the focal position by the condenser lens 21 in the reverse direction to the outward path. As described above, light is guided by the same optical fiber 6a, received by the photodetector 26, and photoelectrically converted. As described above, in the present embodiment, the confocal optical system is constituted by the condenser lens 21.
[0028]
Next, the operation of the present embodiment will be described.
The light emitted from the light source 14 is converted into a parallel light beam through the condenser lenses 15a and 15b, then passes through the beam splitter 17, and is incident on a movable mirror 19 forming a two-dimensional scanner 18.
[0029]
When the movable mirror 19 is two-dimensionally tilted, the light reflected by the movable mirror 19 causes the optical fiber bundle 6 on the base end surface of the optical scanning probe 3 arranged on the focal plane of the condenser lens 21 to move in the XY direction. Scanning is performed in the X and Y directions within the plane, and the light is incident on an optical fiber 6 a constituting the optical fiber bundle 6.
[0030]
In this case, for example, after scanning in the X-axis direction, light is moved in the Y-axis direction by the diameter of the optical fiber 6a, and scanning is repeated in the X-axis direction, thereby forming the optical fiber bundle 6. When light sequentially enters all the optical fibers, optical scanning for one frame is completed, and thereafter, the same scanning is repeated for the next frame.
The optical fiber 6a having the light incident on its proximal end transmits (guides) the light to its distal end, and is further emitted from the distal end surface through the microlens 23 to the inspection site side.
[0031]
In this case, since the optical scanning probe 3 is provided with the bent portion 12 formed by bending the vicinity of the root of the distal end portion 11 of the elongated insertion portion 7 by about 90 degrees, the distal end side can be inserted into the oral cavity 2 and the distal end thereof can be inserted. The surface can easily be brought into contact with the teeth 2a inside the oral cavity 2 and the gingival part on which the inspection of caries, periodontal disease, etc., which is likely to occur, is made on the back side of the teeth 2a.
[0032]
Then, light is emitted to the inspection site side such as the gingival portion where the tip end surface is in contact. Part of the light reflected or scattered near the surface of the inspection site is incident on the optical fiber 6a that has emitted the light.
[0033]
This light is condensed by a condensing lens 21, reflected by a two-dimensional scanner 18, partially reflected by a beam splitter 17, incident on a condensing lens 25, and received by a photodetector 26. You.
[0034]
In this case, light is incident on the optical fiber 6a at the focal position for irradiation by being tilted and scanned by the two-dimensional scanner 18, and return light (reflected or scattered) from the subject side is reflected by the optical fiber 6a. Only the received light follows the optical path opposite to the outward path, and even if light from the subject side is received by an optical fiber other than the focus point, the optical fiber satisfies the confocal condition of the condenser lens 21. Therefore, even if the light is guided toward the photodetector 26 by the condenser lens 25, it is not incident on the pinhole-shaped light receiving portion of the photodetector 26.
[0035]
That is, the movable mirror 19 is disposed on the focal plane of the condenser lens 21, and is tilted by the movable mirror 19 to be incident on the optical fiber 6 a at the focal position of the condenser lens 21, and further receives light reflected on the inspection site side and receives the light. Only the light guided to the condenser lens 25 by the optical fiber 6a is received by the photodetector 26. For this reason, it can be said that the condenser lens 25 also forms a confocal optical system.
In other words, only the light guided to the subject side by the optical fiber 6a that is the focal position of the condenser lens 21 guides the return light from the subject side to the photodetector 26, and the optical fiber that is not at the focal position is an optical fiber. It does not guide the return light to the detector 26.
[0036]
The signal amplified by the signal processing circuit 27 is subjected to A / D conversion and then input to the PC 28 and stored in a memory or the like at an address associated with the drive signal. Image data corresponding to the arrangement of the optical fibers 6a is generated for one frame by the signal data, and the image data is sent to the monitor 5 and displayed on the display surface of the monitor 5 as a confocal image.
[0037]
In the present embodiment, since the light scanning probe 3 is formed to be elongated, the distal end portion 11 can be easily inserted into the oral cavity 2, and the bent portion 12 is provided near the base end of the distal end portion 11. The tip surface can be approached also to the gingival part on the back side of the tooth 2a, so that a microscope image suitable for dental examination can be obtained. In this case, the resolution can be improved by using an optical system that satisfies the confocal condition as the microscope image. Because a high confocal image is obtained, a microscope image (enlarged image) at the cell level, which was not possible in the case of resolution due to the interference phenomenon when using low coherence light, is obtained. This has the effect of making diagnosis easier.
[0038]
FIG. 2 shows a part of an optical scanning probe 3B according to a modification. The optical scanning probe 3B differs from the optical scanning probe 3 in FIG.
As shown in the enlarged view of FIG. 2, an objective lens 29 is provided instead of the cover glass 24.
That is, the objective lens 29 is attached to the distal end member in a water-tight manner such that the distal end surface of the optical fiber 6a constituting the optical fiber bundle 6 becomes the focal plane.
[0039]
That is, as shown in the enlarged view, light incident on the objective lens 29 from the side of the optical fiber 6a disposed on the focal plane is focused at a focal position having a confocal relationship with the optical fiber 6a, and reflected at the focus point Pf. Alternatively, only the scattered light is incident on the optical fiber 6a.
Other configurations are the same as those in FIG.
[0040]
According to this modification, the light emitted from each optical fiber 6a can be condensed by the objective lens 29 and condensed and radiated to the focus position Pf, and the light reflected or scattered at the focus position Pf can be efficiently emitted. The light can be collected by the objective lens 29 and incident on the optical fiber 6a (used for actually emitting light).
[0041]
That is, according to the present modification, light can be efficiently radiated to the inspection site side as compared with the embodiment of FIG. 1, and the light radiated and reflected or scattered to the inspection site side can be efficiently confocal. The optical fiber 6a of the condition can be guided to the photodetector 26 by the optical fiber 6a.
[0042]
Therefore, according to this modification, the S / N can be improved, and a bright and clear confocal image, that is, a microscope image using confocal can be obtained. Therefore, an image with good image quality that can be easily diagnosed is obtained.
[0043]
(Second embodiment)
Next, a dental inspection optical imaging apparatus 1C according to a second embodiment of the present invention will be described with reference to FIG.
The optical imaging apparatus 1C for dental inspection shown in FIG. 3 is inserted into an oral cavity (not shown), and an optical scanning probe 3C for scanning light to the inspection site side, and the optical scanning probe 3C is connected to the optical scanning probe 3C. The apparatus main body 4C that supplies light to the light source, detects return light from the inspection site side by the optical scanning probe 3C and forms an image, and the monitor 5 that displays a video signal from the apparatus main body 4C as an optical imaging image. Be composed.
[0044]
The optical scanning probe 3C has the same external configuration as the optical scanning probe 3 of FIG. 1, but instead of the optical fiber bundle 6, a thin single-mode optical fiber 31 having a diameter of, for example, several microns or less is used. . Further, an optical scanning section 32 is provided at the tip end portion 11. Further, a signal line 33 for transmitting a drive signal to the optical scanning unit 32 is inserted through the optical scanning probe 3C.
[0045]
That is, the optical scanning probe 3C is provided at the rear end of the elongated hard insertion portion 7 through which the optical fiber 31 and the signal line 33 for transmitting light are inserted, and is held by the operator by hand. An optical fiber 31 and a signal line 33 extending rearward from the handheld unit 8 are connected to the apparatus main body 4C by a connector unit 34.
[0046]
Further, the insertion portion 7 has a tip portion 11 formed at the tip thereof, which performs two-dimensional optical scanning on the test site side and receives return light reflected or scattered on the test site side, 11 is provided with a bent portion 12 which is bent (curved) at about 90 degrees in the vicinity of the rear end, and since the bent portion 12 is provided, when the distal end surface of the distal end portion 11 is inserted into the oral cavity 2, the oral cavity 2 The upper or lower teeth and the gingival part at the base end thereof are brought close to each other so that an observation image can be easily obtained.
Further, an optical scanning unit 32 is provided inside the distal end portion 11.
[0047]
A light source 14 such as a semiconductor laser for generating light is provided in the apparatus main body 4C. Light from the light source 14 is incident on one end of an optical fiber 35a via a not-shown condenser lens or the like. The fiber 35a is optically coupled to the other optical fiber 35b by the optical coupler 36 on the way, and the other end of the optical fiber 35a is optically connected to the optical fiber 32 by the connector 34.
Therefore, the light incident on the optical fiber 35a is further incident on the proximal end of the optical fiber 31 from the connector portion 34, and the light is guided toward the distal end side, and is introduced into the distal end portion 11 as shown in the enlarged view of FIG. The light is irradiated to the inspection site side via the arranged optical scanning unit 32.
[0048]
The optical scanning unit 32 includes a condenser lens 37 disposed opposite the distal end face 31 a of the optical fiber 31, a reflection mirror 38 disposed opposite the condenser lens 37, and a two-dimensional scanning disposed opposite the reflection mirror 38. For example, a gimbal mirror 39 serving as a micro machine mirror having a function of performing the following operations: a gimbal mirror 39 is disposed so as to face the gimbal mirror 39, and is fixed to a tip member via a window frame; And an objective lens 40 for converging and irradiating the light.
[0049]
A drive signal is applied to the gimbal mirror 39 from a mirror drive circuit 41 provided in the apparatus main body 4C via a signal line 33, and the gimbal mirror 39 is two-dimensionally tilted by the drive signal and passes through the objective lens 40. The light focused and irradiated on the inspection site scans the focal position two-dimensionally.
[0050]
The confocal optical system according to the present embodiment includes a condenser lens 37, a reflection mirror 38, a gimbal mirror 39, and an objective lens 40. In these optical systems, the focus point Pf focused on the inspection site side and the optical fiber 31 Satisfies the confocal relationship with the front end surface 31a of the lens.
[0051]
That is, in the enlarged view of FIG. 3, light emitted from the distal end surface 31a of the optical fiber 31 is focused in a point shape at the focus point Pf, and light reflected or scattered at this position is incident on the objective lens 40 side. Then, the light is incident on the distal end surface 31a of the optical fiber 31 satisfying the confocal relationship.
In this state, even if the light reflected or scattered at a position other than the focus point Pf is incident on the objective lens 40 side, it is guided to a position different from the distal end surface 31a of the optical fiber 31 and is not incident on the optical fiber 31. . Therefore, confocal optical information with high resolution can be obtained.
[0052]
The return light from the inspection site incident on the distal end surface 31a of the optical fiber 31 is incident on the distal end surface of the optical fiber 35a from the base end of the optical fiber 31, and a part thereof is directed to the optical fiber 35b side by the optical coupler 36. The light is guided, is received by a photodetector 42 disposed at one end thereof, and the like, and is photoelectrically converted.
[0053]
The signal photoelectrically converted by the photodetector 42 is input to a signal processing circuit 43, and after being amplified, A / D converted signal data is input to a PC 44. The PC controls the operation of the mirror drive circuit 41 and receives a mirror drive signal from the mirror drive circuit 41.
The PC 44 stores signal data (image data) input from the signal processing circuit 43 in an information storage unit such as a memory in association with a drive signal of the mirror drive circuit 41.
[0054]
Then, similarly to the first embodiment, two-dimensional image data is generated from one frame of signal data, output to the monitor 5, and displayed on the display surface of the monitor 5 as a confocal image.
In the present embodiment, it is possible to obtain a confocal image at a cell level having a high resolution almost similarly to the first embodiment.
[0055]
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 4 shows an optical scanning probe 3D according to the third embodiment. This optical scanning probe 3D is different from the optical scanning probe 3 of FIG. 1 in that an advancing / retracting adjusting mechanism 51 for advancing / retreating the optical fiber bundle 6 is further provided.
[0056]
In the optical scanning probe 3D, an advance / retreat adjusting mechanism 51 is provided at the rear end of the handheld unit 8. By operating the advance / retreat adjusting mechanism 51, the optical fiber bundle 6 inserted into the optical scanning probe 3D is moved forward and backward, and the position of the distal end surface is moved in the axial direction, and the focus position as the observation position is obtained. So that you can adjust it.
[0057]
As shown in FIG. 4, the optical fiber bundle 6 is movably inserted into the channel 52 in the insertion portion 7 and is movably inserted in the hollow portion also in the handheld portion 8. By rotating the adjusting ring 53, the optical fiber bundle 6 is moved in the longitudinal direction, the position of the distal end surface is moved, and the focal position can be adjusted.
[0058]
As shown in the enlarged view, the advance / retreat adjusting mechanism 51 is rotatably attached to the rear end of the outer cylinder 54 of the handheld unit 8, and has an adjustment ring 53 having the optical fiber bundle 6 inserted therein, and an adjustment ring 53 of the adjustment ring 53. A cylindrical slider 55 having a threaded portion screwed to a threaded portion 53a provided on the inner peripheral surface on the distal end side is provided on the outer peripheral surface, and the optical fiber bundle 6 is fixed on the inner peripheral surface. A piece 55a is engaged, has a guide groove 56a provided along the axial direction of the optical fiber bundle 6, and includes a moving guide member 56 attached to the inner peripheral surface of the outer cylinder 54.
[0059]
The optical fiber bundle 6 is inserted through a pipe 57 having a hollow portion communicating with the channel 12 on the insertion portion 7 side as shown by a dotted line in FIG. You may do it.
Other configurations are the same as those of the first embodiment.
[0060]
According to the present embodiment, the surgeon grasps the hand-held unit 8 by hand and rotates the adjustment ring 53 at the rear end, so that the slider 55 is moved in the guide groove into which the protrusion 55a is engaged according to the direction of rotation. The optical fiber bundle 6 can be moved forward or backward in the direction 56a (the direction indicated by the symbol C in the enlarged view), and the optical fiber bundle 6 fixed thereto is moved by the movement of the slider 55.
[0061]
Therefore, the distal end surface of the optical fiber bundle 6 moves forward and backward in the axial direction inside the cover glass 24, and the observation position can be adjusted in the depth direction orthogonal to the distal end surface.
[0062]
For example, in the case where the vicinity of the contacted position is observed as the observation position in a state where the distal end surface of the distal end portion 11 is in contact, and when the deeper side different from this position is to be observed, the adjustment ring 53 is moved, for example. By performing an operation of rotating the right-handed screw in the forward direction and moving the optical fiber bundle 6 forward, the distal end surface is advanced, and the focus position of light emitted from the distal end surface through the cover glass 24 to the inspection site side. Can be moved deeper. That is, a confocal image can be obtained by focusing on a deeper side.
[0063]
As described above, according to the present embodiment, since the hand-held unit 8 is provided with the advance / retreat adjusting mechanism 51 for moving the optical fiber bundle 6 in the axial direction, the observation position on the inspection site side can be changed in the depth direction. Can be set.
The other effects are the same as those of the first embodiment.
[0064]
FIG. 5 shows an optical scanning probe 3E according to a first modification. The optical scanning probe 3E is provided with an advance / retreat adjustment mechanism 61 for adjusting the advance / retreat by a switch operation, instead of the advance / retreat adjustment mechanism 51 for manually moving forward / backward in FIG.
[0065]
An operation switch 62 for electrically instructing the advance / retreat adjustment mechanism 61 is provided in the vicinity of the advance / retreat adjustment mechanism 61. By operating the operation switch 62, an operation signal is transmitted via a signal line 63. It is supplied to a drive circuit provided on the device body 4 side. Then, the advance / retreat adjusting mechanism 61 can be electrically driven by a drive signal from a drive circuit.
[0066]
As shown in the enlarged view of FIG. A drive that is fixed to the other end of the element 65 and is moved in the axial direction of the optical fiber bundle 6 according to the expansion and contraction of the piezo element 64, and the holding member 65 that holds the optical fiber bundle 6 and the expansion and contraction movement with respect to the piezo element 64 An operation switch 62 for performing an instruction operation for applying a signal (drive voltage) is provided, and a drive circuit for applying a drive voltage to the piezo element 64 via the signal line 63 by operating the operation switch 62.
[0067]
The operation switch 62 includes a first switch 62a for moving the optical fiber bundle 6 forward in the axial direction and a second switch 62b for moving the optical fiber bundle 6 backward.
Then, the surgeon performs a switch operation corresponding to the direction to be moved, thereby applying a drive voltage to the piezo element 64 so that the piezo element 64 can expand and contract. The piezo element 64 is configured by, for example, stacking a piezo element that expands and a piezo element that contracts by applying a voltage. I have to.
[0068]
The drive circuit (not shown) has an integration circuit that generates a signal proportional to the operation time of the operation switch 62, and applies a signal obtained by amplifying the integration circuit to the piezo element 64 as a drive voltage.
[0069]
Therefore, when the operator presses the operation switch 62 for a long time, the operator can move the distal end face of the optical fiber bundle 6 forward or backward substantially in proportion to the time.
According to this modification, the operator can variably set the observation position by simply pressing the switch. That is, the observation position in the depth direction can be variably set by a simpler operation than in the case of FIG.
[0070]
FIG. 6 shows a configuration of a drive circuit 71 provided in an apparatus main body according to a second modification. The drive circuit 71 in FIG. 6 generates a drive signal corresponding to an optical scanning probe having an operation switch 62 additionally provided with an automatic adjustment switch (referred to as 62c).
[0071]
As shown in FIG. 6, an operation signal of the first switch 62a is input to an integration circuit 72a and also to a CPU 73 that performs a control operation. The operation signal of the second switch 62b is input to the integration circuit 72b and also to the CPU 73 that performs a control operation.
[0072]
The signals integrated by the integration circuits 72a and 72b are output to (the expansion piezo element and the contraction piezo element) of the piezo element 64 via the amplification circuits 74a and 74b, respectively.
When no operation signal is input, the CPU 73 resets the integration circuits 72a and 72b.
[0073]
The description so far has a function as a drive circuit for the forward / backward adjusting mechanism 61 in FIG. 5, and in the second modification, when the automatic adjustment switch 62c is further operated, the CPU 73 detects the operation signal and detects the operation signal. The control operation corresponding to the signal is performed.
[0074]
In this case, the CPU 73 takes in, for example, one frame of signal data from the signal processing circuit 27 shown in FIG. 1 through a plurality of high-pass filters 75a to 75c, and obtains information on the frequency distribution of the high-frequency components.
Next, the CPU 73 outputs a signal to be integrated by the integration circuit 72a, for example. This signal is integrated, amplified by the amplifier circuit 74a, and then output to the piezo element 64 (a piezo element for expansion).
[0075]
Then, in this state, the CPU 73 takes in, for example, one frame of signal data from the signal processing circuit 27 via the plurality of high-pass filters 75a to 75c, and obtains information on the frequency distribution of the high-frequency components. Then, a comparison is made between the initially fetched information and the distribution characteristics of the high frequency components. When the high-frequency component further increases, this operation (that is, the same operation with a higher drive voltage) is repeated.
[0076]
Then, the distribution characteristics of the high-frequency components in the previous frame are compared, and when the high-frequency components reach the same state, the output of the signal for integration to the integration circuit 72a is stopped.
[0077]
On the other hand, the CPU 73 outputs a signal to be integrated to the integration circuit 72a and outputs a signal to be integrated to the integration circuit 72b when the distribution characteristic of the high-frequency component in that state is smaller than the initially captured information. Then, the distribution characteristics of the high-frequency components in that state are compared with the information first taken in. When the high-frequency component further increases, this operation (that is, the same operation with a higher drive voltage) is repeated.
Then, the distribution characteristics of the high frequency components in the previous frame are compared, and when the high frequency components reach the same state, the output of the signal for integration to the integration circuit 72b is stopped.
[0078]
By performing such a control operation, it is possible to automatically set the observation state close to the focus state where the image information with the highest frequency component is obtained, that is, the outline at the cell level is the sharpest.
[0079]
Next, an optical scanning probe 3F according to a third modification will be described with reference to FIG. As shown in FIG. 7, the optical scanning probe 3F according to the third modification is such that the objective lens 40 is further moved in the optical axis direction in the optical scanning section 32 of the distal end portion 11 in the optical scanning probe 3C shown in FIG. The optical scanning unit 80 is provided with an adjustment mechanism for adjustment, and the handheld unit 8 is provided with an operation switch 81 for giving an operation instruction of the adjustment mechanism.
[0080]
As shown in the enlarged view of FIG. 7, in the optical scanning unit 80, the objective lens 40 arranged opposite to the gimbal mirror 39 in the optical scanning unit 32 is held by a lens holding member 83, and the lens holding member 83 is a piezo element 84. The other end of the piezo element 84 is fixed to the inner wall of the exterior member of the distal end portion 11 via the piezo element holding member 85.
The optical window immediately before the objective lens 40 is covered with a cover glass 86 in a watertight manner.
[0081]
The piezo element 84 is connected to one end of a signal line 87 for applying a drive voltage for expanding and contracting the piezo element 84. The signal line 87 is connected to the signal line 33 for driving the gimbal mirror 39 in the probe 3F. And the signal line connected to the operation switch 81 of the handheld unit 8 is connected to the apparatus main body.
[0082]
Then, by operating the operation switch 81, the piezo element 84 can be expanded and contracted in the optical axis direction of the objective lens 40, and the objective lens 40 is moved in the optical axis direction by this expansion and contraction.
[0083]
Then, the focus point Pf (focal plane) can be variably set in the direction of the optical axis of the objective lens 40, that is, in the depth direction of the inspection part, and the distal end surface of the distal end portion 11, in this case, the cover glass 84 is moved to the inspection part. When contact is made, the focal position can be variably set within the range of the variable width from a state where the focal plane is a short fixed distance from the contacted surface (in a state where it cannot be variably set). I have.
[0084]
Therefore, when the distal end surface of the distal end 11 is brought into contact with the inspection site side and fixed so that the observation state is not fluctuated, in that state, the clear observation distance is in a prescribed state, but the operation switch must be operated. Accordingly, the position of the focal plane can be variably set in the depth direction, so that the operator can set the focal plane at a desired depth position with respect to the depth direction on the side of the examination region and obtain a confocal image.
[0085]
According to this modification, in addition to the operation and effect of the embodiment of FIG. 3, the position of the focal plane is variably set in the depth direction of the inspection part, and the desired depth position is focused so that a clear image is obtained. A focused image can be obtained.
[0086]
[Appendix]
1. In claim 1, the light guide is a fiber bundle.
2. Appendix 1 is characterized in that a microlens is provided for each fiber at the emission end of the fiber bundle.
3. Appendix 1 or 2, wherein an objective lens is further provided opposite to the emission end of the fiber bundle.
[0087]
4. Appendix 1 is characterized in that the optical scanning means is provided at an incident end of the fiber bundle.
5. In claim 1, the hand-held probe unit has a hand-held unit to be gripped by hand and an insertion unit to be inserted into an oral cavity.
6. Appendix 5 is characterized in that a bent structure is provided on the distal end side of the insertion portion so as to easily approach a gingival portion in an oral cavity.
[0088]
7. According to a second aspect of the present invention, the advance / retreat adjustment mechanism is a manual adjustment mechanism.
7. According to a second aspect of the present invention, the advance / retreat adjustment mechanism is an electric adjustment mechanism operated by a switch.
8. In claim 2, the advance / retreat adjustment mechanism is an automatic adjustment mechanism.
[0089]
9. According to a second aspect, the advance / retreat adjusting mechanism is provided at a tip of the handheld probe unit.
10. In Claim 2, the advance / retreat adjusting mechanism is provided at a portion other than the tip of the handheld probe portion.
11. In the first aspect, the handheld probe unit has a single mode fiber as a light guide, and light scanning means provided in a distal end portion.
[0090]
12. Appendix 11 is characterized in that the optical scanning means is a micro machine mirror.
13. Appendix 11, wherein the optical scanning means is a two-dimensional scanning mirror.
[0091]
【The invention's effect】
According to the present invention as described above, a light source that generates light,
A light guide for transmitting and receiving the light to the subject,
Holding the light guide, a handheld probe unit that can be inserted into the oral cavity,
A confocal optical system capable of satisfying the light in a confocal condition,
Scanning means for scanning the subject with the light,
Light detection means for detecting the reflected and scattered light reflected and scattered from the subject,
An image generation unit that processes a signal detected by the light detection unit and generates a tomographic image of the subject,
Therefore, the tip side of the hand-held probe can be inserted into the oral cavity to perform gingival examination or the like at a cellular level.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an overall configuration of an optical imaging device for dental inspection according to a first embodiment of the present invention.
FIG. 2 is a configuration diagram of an optical scanning probe in a modified example.
FIG. 3 is a configuration diagram showing an entire configuration of an optical imaging device for dental inspection according to a second embodiment of the present invention.
FIG. 4 is a diagram showing a configuration of an optical scanning probe according to a third embodiment of the present invention.
FIG. 5 is a diagram showing a configuration of an optical scanning probe according to a first modification.
FIG. 6 is a block diagram illustrating a configuration of a drive circuit according to a second modification.
FIG. 7 is a diagram showing a configuration of an optical scanning probe according to a third modification.
[Explanation of symbols]
1. Optical imaging device for dental examination
2. Oral cavity
3. Optical scanning probe
4 ... Main unit
5. Monitor
6. Optical fiber bundle
6a: Optical fiber
7. Insertion part
8. Handheld unit
9… Connector
11 ... tip
12 ... Bend
14. Light source
16 ... Pinhole
17 ... Beam splitter
18. Two-dimensional scanner
19 ... Movable mirror
20 ... Scanner drive circuit
21 ... Condensing lens
22… Connector receiver
23 micro lens
25 ... Condensing lens
26 ... Photodetector
27 ... Signal processing circuit
28 ... PC

Claims (3)

A light source for generating light,
A light guide for transmitting and receiving the light to the subject,
Holding the light guide, a handheld probe unit that can be inserted into the oral cavity,
A confocal optical system capable of satisfying the light in a confocal condition,
Scanning means for scanning the subject with the light,
Light detection means for detecting the reflected and scattered light reflected and scattered from the subject,
An image generation unit that processes a signal detected by the light detection unit and generates a tomographic image of the subject,
An optical imaging device for dental examination, comprising: The optical imaging apparatus for dental examination according to claim 1, wherein the handheld probe unit includes an advance / retreat adjustment mechanism that can advance / retreat the light guide with respect to the subject. An optical imaging apparatus for dental examination, wherein the handheld probe section is provided with a bent portion bent at the distal end side of the elongated insertion section.

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