JP2012130477A - Optical tomography image acquisition device - Google Patents

Abstract

The present invention relates to an optical tomographic image acquisition apparatus for dentistry and the like, and an object thereof is to reduce the size of a probe.
In order to achieve this object, according to the present invention, a probe comprises a probe main body 1 and an intraoral insertion portion 2 detachably attached to the probe main body. The provided optical scanning unit 8 irradiates light into the intraoral insertion unit 2 main body and controls the reflected light to be taken in as measurement light, and determines the type of the intraoral insertion unit 2 from the calculation result of the tomographic image calculation unit 23. An intraoral insertion portion type determination unit 31 for determination is provided.
[Selection] Figure 10

Description

  The present invention relates to an optical tomographic image acquisition apparatus utilized for medical purposes, for example.

  Conventionally, the configuration of an optical tomographic image acquisition apparatus utilized for medical purposes has been as follows.

  That is, a light source, a dividing unit that divides the light emitted from the light source, and one of the divided lights are irradiated from the intraoral insertion unit toward the measurement object while changing the irradiation direction by the light scanning unit, A probe that captures reflected light from the measurement target as measurement light from the intraoral insertion section via the optical scanning section, a reference mirror that reflects the other light divided by the dividing section, and a reference mirror Interfering the reflected light and the measurement light captured by the probe to generate interference light, and processing the interference light generated by the interference part to generate tomographic image information of the measurement target An intraoral insertion portion of the probe is detachably provided on the probe main body, and the probe is electrically or mechanically used to determine the type of the intraoral insertion portion. A simple detector It obtained had a structure (e.g., a technique similar to this is described in Patent Document 1).

International Publication No. 2007/060973

  The problem in the conventional example is that the probe is increased in size.

  That is, in the conventional optical tomographic image acquisition apparatus, for example, the intraoral insertion portion of the probe of the dental optical tomographic image acquisition apparatus is provided interchangeably because the type varies depending on the measurement object. Since the measurement range and the optical scanning direction change depending on the type of the internal insertion portion, measurement control differs. An electrical or mechanical detection unit for determining the type of the intraoral insertion portion is provided in the probe, and as a result, the probe has been enlarged.

  Therefore, the present invention aims to reduce the size of the probe.

  In order to achieve this object, the present invention provides a light source, a dividing unit that divides the light emitted from the light source, and one of the divided lights inserted into the oral cavity while changing the irradiation direction by the light scanning unit. A probe that irradiates the measurement target from the section and takes reflected light from the measurement target as measurement light from the intraoral insertion section via the optical scanning section, and the other light split by the split section A reference mirror that reflects light, a light reflected from the reference mirror and a measurement light captured by the probe to interfere with each other to generate interference light, and the interference light generated by the interference part is calculated. A tomographic image processing unit for processing and generating tomographic image information to be measured, and the probe is constituted by a probe main body and an intraoral insertion unit detachably attached to the probe main body, Probe body The optical scanning unit provided in the control unit irradiates light to the intraoral insertion unit main body and controls the reflected light to be taken in as measurement light, and determines the type of intraoral insertion unit from the calculation result of the tomographic image calculation unit An intraoral insertion portion type determination unit is provided to achieve the intended purpose.

  As described above, the present invention provides a light source, a dividing unit that divides the light emitted from the light source, and the one of the divided lights from the intraoral insertion unit to the measurement target while changing the irradiation direction by the light scanning unit. A reference mirror that irradiates and reflects reflected light from the measurement object as measurement light from the intraoral insertion section via the optical scanning section, and a reference mirror that reflects the other light divided by the division section And an interference unit that generates interference light by causing interference between the light reflected from the reference mirror and the measurement light captured by the probe, and an object to be measured by performing arithmetic processing on the interference light generated by the interference unit. A tomographic image calculation unit for generating tomographic image information, and the probe is constituted by a probe main body and an intraoral insertion unit detachably attached to the probe main body, and is provided in the probe main body The optical scanning unit Intraoral insertion part type determination unit for irradiating the intraoral insertion part body with light and controlling the reflected light to be taken in as measurement light, and determining the type of intraoral insertion part from the calculation result of the tomographic image calculation unit Therefore, the probe can be reduced in size.

  That is, in the optical tomographic image acquisition apparatus of the present invention, the optical scanning unit of the probe is controlled to irradiate light into the intraoral insertion unit body and take in the reflected light as measurement light, and is obtained from the measurement light. Since the type of the intraoral insertion part is determined from the calculation result of the tomographic image calculation unit for the interference light, it is possible to determine the type of the intraoral insertion part using the function provided by the apparatus, and the switch or the like It is not necessary to provide an objective or mechanical detection unit, so that the probe can be reduced in size.

The perspective view which shows the usage example of one Embodiment of this invention Perspective view Front view of the display The exploded perspective view The exploded perspective view The exploded perspective view of the principal part Its electrical block diagram Sectional view when using the main part The exploded perspective view of the principal part Cross section of the main part Frequency spectrum diagram of the interference light Flow chart

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

(Embodiment 1)
FIG. 1 shows an example of use of an optical tomographic image acquisition apparatus according to the first embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a probe main body, which is attached to the front of the probe main body 1 in a state where an intraoral insertion portion 2 protrudes.

  As will be described in detail later, as shown in FIG. 1, the optical tomographic image acquisition apparatus according to the present embodiment inserts the intraoral insertion portion 2 into the oral cavity 3 and generates an optical tomographic image of the tooth 4 in the X-axis direction. It is acquired continuously in the Y-axis direction.

  The intraoral insertion portion 2 has a shape that varies depending on the person to be measured, for example, whether the person to be measured is an adult or a child.

  Now, as shown in FIG. 2, the probe body 1 has a pistol shape so that it can be held with one hand, and a control box 6 is connected to the rear end via a cable 5. In the cable 5, wiring for optical input / output and electrical signals are accommodated.

  Further, as shown in FIGS. 4 to 6, the probe main body 1 has a collimator lens 7 that makes the near-infrared light for measurement parallel light, and the near-infrared light from the collimator lens 7 is a light beam. The scanning unit 8 scans in a uniaxial direction, then moves in a direction orthogonal thereto, and then scans in a uniaxial direction again, that is, scans in the same state as a scanning state for image formation in a conventional CRT television. .

  Then, the scanned light is applied to the teeth 4 of FIG. 2 through the wavelength separation prism 9 and the reflection mirror 10 as shown in FIGS. As is understood from the image of the display unit 12 shown in FIG. 3, this irradiation is scanned in the X-axis direction of the tooth 11, and the tomographic image at the time of scanning in the X-axis direction is the display unit 13 in the upper part of FIG. Is displayed.

  In FIG. 3, the display unit 13 displays caries 14 that were not found in the lower display unit 12 as a tomographic image. For example, it can be confirmed that the caries 14 that was only seen as a slight black spot on the surface of the tooth 11 has a large opening downward as in the display unit 13 when a tomographic image is taken. In some cases, dental caries will be treated immediately. That is, early treatment is possible.

  Subsequently, at the next moment, scanning in the X-axis direction is performed again with a slight movement in the Y-axis direction, and the image at this time is displayed on the display unit 13 again. Of course, even if the tomographic image is not immediately displayed on the display unit 13 every time scanning in the X-axis direction as described above, it can be confirmed later by manually operating the dentist while sending the images one by one.

  In order to produce such an image, a light emitting element 15 for illumination is arranged in front of the wavelength separation prism 9 as shown in FIGS. 5 and 6, and the light from the light emitting element 15 passes through the reflection mirror 10. Via the teeth 11. By this irradiation, the light reflected from the teeth and incident on the reflection mirror 10 from the light input / output opening 10a is reflected again by the reflection mirror 10, and subsequently, the wavelength separation prism 9, the internal reflection mirror 28, and the internal reflection mirror 29. And is detected as an image by the camera 16 and becomes the image shown on the display unit 12 described above.

  That is, the display unit 12 is for displaying which tooth 11 tomographic image is currently being acquired. While viewing the image of the display unit 12, the display unit 12 displays the near image shown in FIGS. Infrared light scanning is performed.

  Thus, as shown in FIGS. 4 and 5, the scanned near-infrared light travels straight through the wavelength separation prism 9, passes through the collimator lens 7, and then passes through the cable 5 (shown in FIG. 2). Returning to the control box 6, the image processing is performed here, and the image after this processing is displayed on the display unit 13 of FIG. 3. That is, FIG. 3 shows the display unit 17 of the control box 6.

  Here, the image processing in the control box 6 will be described.

  The light source 18 in FIG. 7 is a wavelength swept light source. The light emitted from the light source 18 is divided by the dividing unit 19, and a part of the light is supplied to the optical scanning unit 8 via the cable 5. Scanning in the X-axis direction and the Y-axis direction is performed.

  The remaining light divided by the dividing unit 19 is reflected by the reference mirror 20 and supplied to the interference unit 21. In the interference unit 21, interference light is generated by causing interference between the light reflected by the reference mirror 20 and the light returned through the optical scanning unit 8 and the cable 5. The interference light is converted into an electric signal by the light receiving unit 22 and further A / D converted, and the result is supplied to the tomographic image calculation unit 23.

  The tomographic image computation unit 23 performs FFT computation on the interference light A / D conversion result to obtain tomographic image information to be measured.

  Although details will be described later, when the type determination of the intraoral insertion unit 2 is performed, the intraoral insertion unit type determination unit 31 uses the tomographic image information obtained by the tomographic image calculation unit 23 to insert into the oral cavity. The type of the unit 2 is determined, and the result is supplied to the control unit 24.

  The control unit 24 controls the optical scanning unit 8 and the observation image calculation unit 25 according to the type of the intraoral insertion unit 2, and displays the observation image on the display unit 12 shown in FIG. 3 in real time. Further, the tomographic image calculation unit 23 is controlled by the control unit 24 to display the tomographic image on the display unit 13 shown in FIG.

  Here, when the tomographic image is displayed on the display unit 13, the display range of the tomographic image will be described.

  The optical path length X from the dividing section 19 to the interference section 21 via the reference mirror 20 and the tip of the optical path of the intraoral insertion section 2 of the probe, that is, the light entrance / exit of the probe are folded back. Thus, the difference from the optical path length Y to the interference portion appears as a spectrum of interference light. Here, the position where the optical path X = Y is the display start position of the tomographic image displayed on the display unit 13. This display start position will be used in the following description.

  The optical scanning unit 8 in the present embodiment scans near-infrared light from the collimator lens 7 in a uniaxial direction (X direction in FIGS. 4 and 5) by the galvano scanner 26 shown in FIGS. 4, 5, and 6. The galvano scanner 27 scans in the other axis direction (Y direction in FIGS. 4 and 5) orthogonal to the one axis.

  FIG. 8 is a view showing a cross-sectional structure when the intraoral insertion portion 2 of the probe main body 1 is inserted into the oral cavity. As described above, the intraoral insertion portion 2 is provided in front of the probe main body 1, the reflection mirror 10 serving as a light deflection member is provided at the tip thereof, and further, as shown in FIG. A protective cover 38 which is a cover body is provided so as to divide the intraoral insertion portion 2 and the probe main body 1 into front and rear.

  Returning to FIG. 8 again, as described above, the light incident from the probe body 1 side passes through the protective cover 38, is deflected by the reflection mirror 10 that is a light refracting member, and passes through the opening 39. The tooth 4 that is the object of measurement is irradiated. The light irradiated on the teeth 4 is reflected and again passes through the protective cover 38 from the opening 39 via the reflection mirror 10 and returns to the probe body 1 side as measurement light.

  A point S serving as the display start position of the tomographic image described above is set between the opening 39 of the probe and the tooth 4.

  The definition of the display start position S will be described. First, the optical path length X from the dividing unit 19 to the interference unit 21 via the reference mirror 20 and the optical path length Y from the dividing unit 19 to the interference unit 2 via the intraoral insertion part 2 of the probe in FIG. The position where the difference between the two becomes equal is the display start position S.

  The surface of the tooth 4 and the image in the tomographic direction are acquired from the point of the display start position.

  Now that the basic configuration and operation of the present embodiment have been understood, the characteristic points of the present embodiment will be described below.

  As described above, since the shape of the intraoral insertion portion 2 of the probe according to the present embodiment differs depending on the person to be measured, for example, whether the person to be measured is an adult or a child, the probe main body 1 can be replaced. It is attached to become.

  In the present embodiment, the type of the intraoral insertion portion 2 attached to the probe main body 1 can be automatically determined.

  FIG. 10 is a diagram illustrating a method of determining the type of the intraoral insertion unit 2.

  (A) of FIG. 10 is a type of the intraoral insertion part 2 for back teeth observation for adults in a dental optical tomographic image acquisition apparatus, and (b) is for back teeth observation for children. It is a type of the intraoral insertion part 2.

  In the above-mentioned types for posterior teeth observation, the irradiation light and the measurement light can be deflected so that the posterior teeth can be easily observed by providing the reflecting mirror 10 at the distal end of the intraoral insertion portion 2. The image is easy to acquire.

  FIG. 10C shows the type of intraoral insertion portion 2 for anterior tooth observation. In order to make it easy to observe the front teeth, the front teeth are directly irradiated with the irradiation light without being deflected, and the measurement light is taken in. It is configured.

  Next, a method of determining the type of the intraoral insertion portion 2 for back tooth observation will be described with reference to FIGS.

  First, the irradiation direction of the optical scanning unit 8 is controlled to be the type determining optical path 40 of the intraoral insertion unit 2, and the irradiation wall 41 provided behind the opening 39 of the intraoral insertion unit 2 is irradiated. Next, the light applied to the irradiation wall 41 becomes reflected light, returns again through the type determination optical path 40, is taken into the interference unit 21 as measurement light via the optical scanning unit 8, and is computed tomographic image calculation unit 23. Obtains the frequency spectrum of the interference light.

  Next, the frequency spectrum is shown in FIG. 11, and the intraoral insertion portion type determination unit 31 calculates a frequency peak 43 that exceeds a predetermined threshold 42 of the obtained frequency spectrum, and from the frequency 44 of the frequency peak 43. The type of the intraoral insertion part 2 is determined.

  In FIG. 11, FIG. 11 (a) shows the frequency spectrum of the adult intraoral insertion part 2 of FIG. 10 (a), and FIG. 11 (b) shows the oral cavity for children of FIG. 10 (b). The frequency spectrum of the insertion part 2 is shown.

  In the embodiment of the present invention, the adult oral cavity insertion portion 2 shown in FIG. 10A and the child oral cavity insertion portion 2 shown in FIG. Are the same but have different heights (lengths in the vertical direction in FIG. 10).

  In such a case, the difference in height appears as a difference in the path length of the measurement light. Therefore, in the frequency spectrum in which the path length of the measurement light is recognized by the frequency, this difference is different from the frequency spectrum described above. It appears as a frequency difference between frequency peaks. Specifically, in the intraoral insertion part 2 for children with a short path length, the frequency 44b of FIG. 11B is obtained. This frequency 44b is for adults whose path length is longer than that of the intraoral insertion part 2 for children. In the intraoral insertion part 2, it becomes the frequency 44a of Fig.11 (a), and a difference appears. The intraoral insertion part type determination unit 31 determines the type of the intraoral insertion part 2 based on this frequency.

  Next, a method for determining the type of the intraoral insertion portion 2 for anterior tooth observation shown in FIG.

  The irradiation direction of the optical scanning unit 8 is controlled so as to be the type determining optical path 40 of the intraoral insertion unit 2, and the irradiation wall 46 provided around the rear opening 45 of the intraoral insertion unit 2 is irradiated. Next, the light applied to the irradiation wall 46 becomes reflected light, returns again through the type determination optical path 40, is taken into the interference unit 21 as measurement light via the optical scanning unit 8, and is computed tomographic image calculation unit 23. Obtains the frequency spectrum of the interference light.

  This frequency spectrum is shown in FIG.

  There is no frequency peak in the frequency spectrum of FIG. This is because the position of the irradiation wall 46 is provided outside the interference range. This interference range is determined by the coherence length of the light output from the light source 18, and the interference range in this embodiment is a range of ± 10 mm with the display start position S in FIG. 8 as the center.

  That is, the type determination of the intraoral insertion part 2 for anterior tooth observation shown in FIG. 10C is performed by detecting that the path length of the measurement light at the time of the type determination of the intraoral insertion part is outside the interference range. The type is determined.

  That is, in the optical tomographic image acquisition apparatus according to the embodiment of the present invention, the optical scanning unit 8 of the probe controls the irradiation of the intraoral insertion unit 2 main body with light to take in the reflected light as measurement light, and Since the type of the intraoral insertion unit 2 is determined from the calculation result of the tomographic image calculation unit 23 of the interference light obtained from the measurement light, the tomographic image acquisition function provided in the apparatus is used. The type can be determined, and it is not necessary to provide an electrical or mechanical detection unit such as a switch. Therefore, the probe can be reduced in size.

  Next, when this type determination is performed will be described.

  FIG. 12 is a flowchart showing the start timing of the type determination.

  First, after the system is started, it is determined whether or not there is a measurement start request (S1). Next, when there is a measurement start request, the type determination of the intraoral insertion portion 2 described above is performed (S2). Next, the setting is made according to the type (S3), then the tomographic image of the measurement object is measured (S4), and the measurement is terminated (S5).

  As described above, when the type determination of the intraoral insertion portion 2 is performed every time the measurement is performed, even when the user replaces the intraoral insertion portion 2 at the time of turning off the power or not measuring, Appropriate measurement according to the type of the intraoral insertion part 2 becomes possible.

  Furthermore, by providing a lock mechanism that makes it impossible to replace the intraoral insertion part 2 when the power is turned on, the type determination of the intraoral insertion part 2 can be performed only when the power is turned on, thus simplifying the system design. become.

  As described above, the present invention provides a light source, a dividing unit that divides light emitted from the light source, and a light scanning unit that changes the irradiation direction of the divided one light. A probe that irradiates a measurement target from the intraoral insertion part and takes reflected light from the measurement target as measurement light from the intraoral insertion part via the optical scanning part and the split part. A reference mirror that reflects the other light, a light reflected from the reference mirror, and an interference unit that generates interference light by interfering with the measurement light captured by the probe, and interference generated by the interference unit A tomographic image calculation unit that calculates light tomographic image information by processing light, and the probe includes a probe main body and an intraoral insertion unit that is detachably attached to the probe main body. And the probe The optical scanning unit provided in the body irradiates the intraoral insertion unit body with light, and controls to reflect the reflected light from the intraoral insertion unit body as measurement light, and from the calculation result of the tomographic image calculation unit Since the intraoral insertion part type determination unit for determining the type of the intraoral insertion part is provided, the probe can be miniaturized.

  That is, in the optical tomographic image acquisition apparatus of the present invention, the optical scanning unit of the probe controls the irradiation to the intraoral insertion unit main body, and takes in the reflected light from the intraoral insertion unit main body as measurement light. Since the type of the intraoral insertion part is determined from the calculation result of the tomographic image calculation unit of the interference light obtained from the measurement light, the type of the intraoral insertion part is determined using the function of the apparatus. This makes it possible to reduce the size of the probe because there is no need to provide an electrical or mechanical detector such as a switch.

  Therefore, for example, it is expected to be widely used as a dental optical tomographic image acquisition apparatus.

DESCRIPTION OF SYMBOLS 1 Probe main body 2 Intraoral insertion part 3 Oral cavity 4 Tooth 5 Cable 6 Control box 7 Collimator lens 8 Optical scanning part 9 Wavelength separation prism 10 Reflection mirror 11 Tooth 12 Display part 13 Display part 14 Caries 15 Light emitting element 16 Camera 17 Display part 18 Light source 19 Dividing unit 20 Reference mirror 21 Interfering unit 22 Light receiving unit 23 Tomographic image calculation unit 24 Control unit 25 Observation image calculation unit 26 Galvano scanner 27 Galvano scanner 28 Internal reflection mirror 29 Internal reflection mirror 30 Light input / output unit mount screw 31 Oral insertion portion type determination unit 38 Protective cover 39 Opening 40 Type determination optical path 41 Irradiation wall 42 Threshold 43 Frequency peak 44, 44a, 44b Frequency 45 Rear opening 46 Irradiation wall

Claims (7)

A light source, a division unit that divides the light emitted from the light source, and one of the divided lights is irradiated from the intraoral insertion portion toward the measurement target while changing the irradiation direction by the light scanning unit, and the measurement target Reflected from the intraoral insertion part via the optical scanning part as a measurement light, a reference mirror reflecting the other light divided by the dividing part, and reflected from the reference mirror An interference unit that generates interference light by causing interference between the measured light captured by the probe and the measurement light captured by the probe, and a tomographic image that generates tomographic image information to be measured by performing arithmetic processing on the interference light generated by the interference unit An image calculation unit,
The probe includes a probe main body and an intraoral insertion portion that is detachably attached to the probe main body, and an optical scanning unit provided in the probe main body irradiates the intraoral insertion portion main body with light. An optical tomographic image acquisition apparatus provided with an intraoral insertion portion type determination unit that controls to capture the reflected light as measurement light and determines the type of the intraoral insertion unit from the calculation result of the tomographic image calculation unit. The optical tomographic image acquisition apparatus according to claim 1, wherein the tomographic image calculation unit includes a display unit that outputs tomographic image information. The optical tomographic image acquisition apparatus according to claim 1 or 2, wherein the intraoral insertion part type determination unit performs a type determination of the intraoral insertion part after the optical tomography image acquisition apparatus is powered on. The optical tomographic image acquisition apparatus according to any one of claims 1 to 3, wherein the intraoral insertion part type determination unit is configured to perform a type determination of the intraoral insertion part at the start of measurement. The optical tomographic image acquisition apparatus according to any one of claims 1 to 4, wherein an irradiation wall for irradiating light is provided in the periphery of the opening for the type determination in the intraoral insertion portion main body. The optical tomographic image acquisition apparatus according to any one of claims 1 to 5, wherein the intraoral insertion part type determination unit performs type determination based on a path length of measurement light when determining the type of the intraoral insertion part. 6. The intraoral insertion part type determination unit according to any one of claims 1 to 5, wherein the type determination is performed by detecting that the path length of the measurement light at the time of determining the type of the intraoral insertion part is outside the interference range. The optical tomographic image acquisition apparatus described.

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