JP2012020052A - Teeth observation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and visually recognize peripheral parts of teeth without affecting image quality of a fluorescence image obtained by imaging faint fluorescence from a lesion part such as caries in the teeth.SOLUTION: A teeth observation device 1 includes a light illumination section 3 that irradiates the teeth A with excitation light, a light detecting section 4 that is provided separately from the light illumination section 3 and that detects light from the teeth A, and a control section 5. The light detecting section 4 comprises: a near-infrared light illumination section 15 that applies near-infrared light for external observation with a wavelength longer than the wavelength of the excitation light toward the teeth A; an illumination light detecting section 16 that detects the excitation light and that does not detect the near-infrared light for external observation; an excitation light cut filter 13 that blocks light in a band of wavelength equal to/shorter than the wavelength of the excitation light, included in the light from the teeth A, and that transmits the fluorescence generated from a fluorescence probe and the near-infrared light for external observation; and an imaging section 14 that images the fluorescence and the near-infrared light for external observation. The control section 5 stops irradiation from the near-infrared light illumination section 15 when the illumination light detecting section 16 detects the excitation light.

Description

  The present invention relates to a tooth observation apparatus.

  2. Description of the Related Art Conventionally, an intraoral imaging apparatus that simultaneously irradiates a tooth with excitation light that generates fluorescence from a lesioned part of a tooth and visible light for observing the periphery of the lesioned part is known (see, for example, Patent Document 1). .)

International Publication No. 2005/104926

  However, when the excitation light and the visible light are irradiated simultaneously as in the intraoral photographing apparatus disclosed in Patent Document 1, autofluorescence is generated in the teeth by irradiating the visible light. The self-fluorescence thus produced is mixed with the fluorescence generated from the lesion, and there is a disadvantage that a clear image cannot be obtained.

  The present invention has been made in view of the circumstances described above, and without affecting the image quality of a fluorescent image obtained by photographing weak fluorescence from a lesion such as caries existing in the tooth. An object of the present invention is to provide a tooth observation device that can easily visually recognize a peripheral portion.

In order to achieve the above object, the present invention provides the following means.
The present invention includes a light irradiation unit that irradiates a tooth with excitation light having a wavelength in the near infrared region, a light detection unit that is provided separately from the light irradiation unit, and detects light from the tooth, A control unit for controlling, a near-infrared light irradiating unit that irradiates a tooth with a near-infrared light for external observation having a longer wavelength than the excitation light, and detecting the excitation light. Irradiation light detection unit that does not detect near-infrared light for external observation, and blocks light in the wavelength band including and below the wavelength of the excitation light out of the light from the tooth, while applying the excitation light to the tooth An excitation light cut filter that transmits the fluorescence generated from the applied fluorescent probe and external observation near-infrared light, and an imaging unit that captures the fluorescence transmitted through the excitation light cut filter and external observation near-infrared light The control unit detects the excitation light by the irradiation light detection unit. Wherein providing a tooth observation device for stopping the irradiation of near infrared light for external observation from the near-infrared light irradiating portion when.

  According to the present invention, the light detection unit is arranged opposite to the tooth, and is reflected on the tooth by irradiating near infrared light for external observation from the near infrared light irradiation unit provided in the light detection unit. The near-infrared light for external observation passes through the excitation light cut filter and is photographed by the imaging unit. Thereby, the image of the near-infrared light for external observation can be acquired, and the observer can determine the observation position of the tooth based on the image.

  In this state, the fluorescent probe that is specifically accumulated in a lesion such as caries is applied to the tooth by irradiating excitation light with the light irradiation part arranged at an appropriate position with respect to the tooth. When excited, fluorescence is generated. Further, a part of the excitation light is reflected on the surface of the tooth or transmitted / scattered inside the tooth and detected by the irradiation light detection unit.

  When excitation light is detected by the irradiation light detection unit, the control unit stops irradiating near-infrared light for external observation from the near-infrared light irradiation unit. Becomes incident. And since excitation light is interrupted | blocked by the excitation light cut filter provided in the light detection part, only the fluorescence which permeate | transmitted the excitation light cut filter can be image | photographed with an imaging part, and a clear fluorescence image can be acquired. it can.

  That is, according to the present invention, in the state where the light irradiation unit is not correctly set with respect to the tooth, the observation position of the tooth can be easily specified by the image of the near-infrared light for external observation, and the light irradiation After the part is correctly set on the tooth, by irradiating near-infrared light for external observation, weak fluorescence from lesions such as caries is acquired as a clear fluorescent image with little noise. Can be observed.

  In the above invention, the light irradiating unit irradiates the tooth with the internal observation near-infrared light having a wavelength longer than the excitation light and a wavelength band different from the external observation near-infrared light, The excitation light cut filter also transmits the near-infrared light for internal observation, the irradiation light detection unit also detects the near-infrared light for internal observation, and the control unit includes the irradiation light detection unit described above. Even when the near-infrared light for internal observation is detected, the irradiation of the near-infrared light for external observation from the near-infrared light irradiation unit may be stopped.

  In this way, when the near-infrared light for internal observation is irradiated from the light irradiation unit, the near-infrared light for internal observation reaches the deep part of the tooth and is then emitted to the outside of the tooth by scattering. The light is incident on the light detection unit. Since the excitation light cut filter also transmits near-infrared light for internal observation, an image of the near-infrared light for internal observation is acquired by the imaging unit. Since the near-infrared light for internal observation includes information on the internal structure of the tooth by scattering inside the tooth, the internal structure of the tooth can be visually recognized from the image.

  In this case, when the near-infrared light for internal observation is detected by the irradiation light detection unit, the control unit stops the irradiation of the near-infrared light for external observation. Only the near-infrared light for internal observation is incident. And since excitation light is interrupted | blocked by the excitation light cut filter provided in the light detection part, the fluorescence and the near-infrared light for internal observation which permeate | transmitted the excitation light cut filter can be image | photographed with an imaging part, The position of a lesion such as caries with respect to the internal structure can be easily confirmed.

Further, in the above invention, a display unit that displays an image of the fluorescence acquired by the imaging unit and the near-infrared light for external observation is provided, and the control unit is for external observation from the near-infrared light irradiation unit. The presence or absence of near-infrared light irradiation may be displayed on the display unit.
In this way, it is determined whether the image displayed on the display unit is an external image of the tooth by the external observation near infrared light or the internal image of the tooth by the internal observation near infrared light. It can be easily judged. Regardless of the irradiation of excitation light from the light irradiation unit or near-infrared light for internal observation, if an image of near-infrared light for external observation is displayed, this can be quickly confirmed, and the position of the light irradiation unit Adjustments can be made.

  According to the present invention, it is possible to easily visually recognize a peripheral portion of a tooth without affecting the image quality of a fluorescent image obtained by photographing weak fluorescence from a lesion such as caries existing in the tooth. There is an effect.

It is a whole lineblock diagram showing the tooth observation device concerning one embodiment of the present invention. It is a figure which shows the wavelength band of the filter of the tooth observation apparatus of FIG. 1, and the wavelength band of the excitation light and near-infrared light emitted from a light source part. It is a time chart explaining the observation mode by the control part of the tooth observation apparatus of FIG. It is a figure which shows an example of the near-infrared light image for external observations acquired by the tooth observation apparatus of FIG. It is a figure which shows an example of the fluorescence image acquired by the tooth observation apparatus of FIG. 1, the near-infrared light image for internal observation, and these synthesized images.

A tooth observation device 1 according to an embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the tooth observation apparatus 1 according to the present embodiment includes a light source unit 2, a light irradiation unit 3, a light detection unit 4 provided separately from the light irradiation unit 3, and these The control part 5 which controls is provided.

  As shown in FIG. 2, the light source unit 2 has an LD (laser diode) 6 that generates excitation light having a wavelength width of 740 to 760 nm with a center wavelength of 750 nm, and a wavelength width of 810 to 830 nm with a center wavelength of 820 nm. A first LED (light-emitting diode) 7 that generates internal observation near-infrared light; and a second LED 8 that generates external observation near-infrared light having a wavelength range of 890 to 910 nm with a center wavelength of 900 nm. ing.

  The light irradiation unit 3 includes a plurality of optical fibers 9 that respectively guide the excitation light and the internal observation near infrared light emitted from the LD 6 and the first LED 7. The emission ends 9a of these optical fibers 9 are gathered at one place so that excitation light and near-infrared light for internal observation can be irradiated to substantially the same position of the tooth A. In the figure, reference numeral 20 denotes a coupling lens.

  The light detection unit 4 includes an objective lens 10 that collects light returning from the tooth A, an image fiber 11 that guides the light collected by the objective lens 10, and light guided by the image fiber 11. A condensing lens 12 that condenses, and excitation that transmits fluorescence, internal observation near-infrared light, and external observation near-infrared light and blocks excitation light among the light collected by the condensing lens 12 A light cut filter 13 and an imaging element 14 such as a CCD that captures the fluorescence, the near-infrared light for internal observation, and the near-infrared light for external observation that have passed through the excitation light cut filter 13 are provided.

  As shown in FIG. 2, the wavelength characteristic of the excitation light cut filter 13 transmits light having a wavelength of about 800 nm or more and blocks light having a shorter wavelength than that. Thereby, the excitation light guided through the image fiber 11 is blocked by the excitation light cut filter 13, and the fluorescence generated by the irradiation of the excitation light, the near-infrared light for internal observation, and the near-infrared light for external observation are The excitation light cut filter 13 can be transmitted.

  The light detection unit 4 includes an optical fiber that is arranged in the vicinity of the objective lens 10 and emits near-infrared light for external observation from the second LED 8 arranged in the light source unit 2 toward the tooth A. Of the light from the near infrared light irradiation unit 15 and the tooth A, the excitation light emitted from the LD 6 and the near infrared light for internal observation emitted from the first LED 7 are detected, and the near infrared light for external observation is detected. And an irradiation light detection unit 16 configured not to detect light.

  The irradiation light detection unit 16 includes a light guide 17 that guides light emitted from the tooth A, and a wavelength band of excitation light and internal observation near-infrared light in the light guided by the light guide 17. A band-pass filter 18 that transmits light and blocks light in the wavelength band of the near-infrared light for external observation, and a PD (photodiode) 19 that detects light transmitted through the band-pass filter 18 are provided.

  As shown in FIG. 3, the control unit 5 includes a monitor mode in which neither the excitation light with the intensity higher than a predetermined threshold nor the near-infrared light for internal observation is detected by the PD 19 of the irradiation light detection unit 16, Control of turning on and off of the LD 6 and the first and second LEDs 7 and 8 in accordance with two observation modes of the caries mode in which either excitation light with an intensity equal to or greater than the threshold value or near-infrared light for internal observation is detected It is supposed to be.

That is, as shown in FIG. 3, the control unit 5 controls the LD 6 and the first LED 7 so that the LD 6 and the first LED 7 are alternately lit for each frame in which an image is acquired by the imaging device 14. It is controlled to repeat turning off.
In the monitor mode in which neither the excitation light nor the near-infrared light for internal observation is detected by the PD 19 as light having an intensity equal to or greater than a predetermined threshold, the control unit 5 turns on the second LED 8.

At this time, the near-infrared light for external observation emitted from the second LED 8 is applied to the tooth A from the cheek side portion or the lingual side portion of the tooth A by the light detection unit 4, and the reflected light is reflected from the objective lens 10. The light is condensed by the image fiber 11, guided by the image fiber 11, condensed by the condenser lens 12, and photographed by the image sensor 14. Thereby, the imaging device 14 acquires a near-infrared light image for external observation as shown in FIG.
Further, in the tooth observation device 1 according to the present embodiment, as shown in FIG. 4, the type of the observation mode, in this case, “monitor” indicating the monitor mode is displayed on the monitor 21. ing.

On the other hand, in the caries mode in which either the excitation light or the near-infrared light for internal observation is detected by the PD 19 as light having an intensity equal to or greater than a predetermined threshold, the control unit 5 turns the second LED 8 to the OFF state.
At this time, the fluorescence probe of the tooth A is excited by the excitation light emitted by the LD 6, and the fluorescence generated thereby is collected by the objective lens 10, guided by the image fiber 11, and collected by the collection lens 12. The light is emitted and photographed by the image sensor 14. Thereby, a fluorescence image is acquired by the image sensor 14.

  Moreover, after the near-infrared light for internal observation emitted from the first LED 7 reaches the inside of the tooth A, it is scattered and emitted to the outside of the tooth A, and is condensed by the objective lens 10, and is image fiber 11. , The light is condensed by the condenser lens 12, and is photographed by the image sensor 14. Thereby, the near infrared light image for internal observation is acquired by the image sensor 14.

  Then, as shown in FIG. 5, the control unit 5 generates a composite image G3 in which the fluorescent images G1 and the internal observation near-infrared light image G2 alternately sent from the imaging device 14 are superimposed, and the monitor 21 To be displayed. Also in this case, as shown in FIG. 4, the type of observation mode, in this case, “caries” indicating the caries mode is displayed on the monitor 21.

In order to observe the tooth A using the tooth observation device 1 according to the present embodiment configured as described above, first, a fluorescent probe (for example, osteosense) is supplied to the tooth A, and then washed. deep.
Next, as shown in FIG. 1, the objective lens 10, the near-infrared light irradiation unit 15, and the light guide 17 disposed at the tip of the light detection unit 4 are made to face the cheek side surface or the tongue side surface of the tooth A. Arrange.

  At this time, since the light irradiation unit 3 is not yet installed, neither the excitation light with the intensity equal to or higher than a predetermined threshold value nor the near-infrared light for internal observation is detected in the image sensor 14, and the control unit 5 Is in monitor mode. Therefore, the near-infrared light for external observation is emitted from the second LED 8, the near-infrared light for external observation is guided through the near-infrared light irradiation unit 15, and is directed from the front end of the light detection unit 4 toward the tooth A. Is irradiated. Then, the reflected light of the external observation near-infrared light on the tooth A is photographed by the imaging device 14 via the objective lens 10, the image fiber 11, and the condenser lens 12, and a near-infrared light image for external observation is acquired. Is displayed on the monitor 21.

  Also in the monitor mode, either the excitation light from the LD 6 or the near-infrared light for internal observation from the first LED 7 is emitted from the light irradiation unit 3, so that the operator operates the light irradiation unit 3. As shown in FIG. 1, when the tip is disposed at a position facing the occlusal surface of the tooth A, either the excitation light or the near-infrared light for internal observation is light having an intensity equal to or higher than a predetermined threshold value. As detected by the PD 19.

  At this time, the control unit 5 switches the observation mode to the caries mode, turns off the second LED 8, and stops the irradiation with the near-infrared light for external observation. Thereby, in the frame in which the LD 6 generates the excitation light, the excitation light excites the fluorescent probe to generate fluorescence, so that the fluorescence from the fluorescent probe is collected by the objective lens 10 and the image fiber 11 and The image is captured by the image sensor 14 through the condenser lens 12, and a fluorescence image G1 is acquired. At this time, a part of the excitation light is also collected by the objective lens 10, but is blocked by the excitation light cut filter 13, so that only the fluorescence is photographed by the image sensor 14 and a clear fluorescence image G1 can be obtained. it can.

On the other hand, in the frame in which the near-infrared light for internal observation from the first LED 7 is emitted, the near-infrared light for internal observation that has reached the deep part of the tooth A and is scattered is collected by the objective lens 10. The image sensor 11 passes through the image fiber 11 and the condensing lens 12, and is imaged by the imaging device 14 to obtain the near-infrared light image G2 for internal observation.
The fluorescent image G1 and the internal observation near-infrared light image G2 are alternately acquired for each frame, and the control unit 5 acquires a composite image G3 that is combined so that both are superimposed.

  As described above, the near-infrared light for internal observation includes information on the internal structure of the tooth A. Therefore, the near-infrared light image G2 for internal observation obtained by photographing this is the internal structure of the tooth A. That is, the outline of the enamel layer A1 and the boundary line between the enamel layer A1 and the dentin layer A2 can be clearly seen. Thereby, in the near-infrared light image G2 for observing the internal structure showing the internal structure of the tooth A, a high-luminance region of the fluorescent image G1 showing the lesioned part B such as caries is displayed, and the progress of the lesioned part B in the tooth A is progressed. The degree can be observed.

  In this case, according to the tooth observation apparatus 1 according to the present embodiment, in the caries mode, the control unit 5 performs control so that the first and second LEDs 7 and 8 are turned off in the frame for acquiring the fluorescent image G1. Therefore, no near-infrared light is captured by the image sensor 14, and there is an advantage that a clear fluorescent image G <b> 1 only with fluorescence by irradiation with excitation light can be acquired.

In addition, in the caries mode for acquiring the fluorescent image G1 and the near-infrared light image G2 for observing the internal structure, the control unit 5 controls the second LED 8 to be turned off. A fluorescent image G1 obtained by photographing weak fluorescence from a lesion B such as a caries existing in the tooth A by preventing external light from being detected together with fluorescence and near-infrared light for internal structure observation; The image quality of the near-infrared light image G2 for observing the internal structure showing the internal structure can be prevented from deteriorating.
In addition, in this embodiment, although the case where the 1st LED7 which generate | occur | produces near-infrared light was provided was illustrated and demonstrated, it replaced with this and does not need to provide the 1st LED7.

A tooth 1 tooth observation apparatus 3 light irradiation part 4 light detection part 5 control part 13 excitation light cut filter 14 imaging element (imaging part)
15 near infrared light irradiation part 16 irradiation light detection part 21 monitor (display part)

Claims (3)

A light irradiation unit that irradiates the teeth with excitation light having a wavelength in the near infrared region; and
A light detection unit that is provided separately from the light irradiation unit and detects light from the teeth;
A control unit for controlling these,
A near-infrared light irradiating unit that irradiates a tooth with a near-infrared light for external observation having a wavelength longer than that of the excitation light toward the teeth, and a near-infrared light for external observation that detects the excitation light. Irradiation light detection unit that does not detect, and fluorescence generated from a fluorescent probe applied to the tooth by irradiation with excitation light while blocking light in the wavelength band including and below the excitation light among the light from the tooth And an excitation light cut filter that transmits external observation near-infrared light, and an imaging unit that captures fluorescence transmitted through the excitation light cut filter and external observation near-infrared light,
The said control part is a tooth observation apparatus which stops irradiation of the near infrared light for external observations from the said near infrared light irradiation part, when the said irradiation light detection part detects the said excitation light. The light irradiating unit irradiates the tooth with internal observation near-infrared light having a wavelength longer than the excitation light and a wavelength band different from the external observation near-infrared light,
The excitation light cut filter also transmits near-infrared light for internal observation,
The irradiation light detection unit detects the near-infrared light for internal observation,
The said control part stops irradiation of the near infrared light for external observation from the said near infrared light irradiation part, also when the said irradiation light detection part detects the said near infrared light for internal observations. The tooth observation apparatus of description. A display unit for displaying an image of fluorescence and external infrared light for external observation acquired by the imaging unit;
The tooth observation apparatus according to claim 1, wherein the control unit causes the display unit to display presence / absence of irradiation of near-infrared light for external observation from the near-infrared light irradiation unit.

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