JP6543160B2 - probe - Google Patents

Description

  The present invention relates to, for example, a probe used in an optical coherence tomographic imaging apparatus that captures a tomographic image inside an object by using light coherence (coherence).

  A dental optical coherence tomography image generator (Optical Coherence Tomography: hereinafter referred to as an OCT apparatus) distributes laser light emitted from a light source to measurement light and reference light and measures light from a probe (handpiece). While irradiating the intraoral tissue, the reference light is irradiated to the reference mirror. Furthermore, the OCT apparatus collects the scattered light reflected back from the intraoral tissue with a probe, combines the scattered light and the reflected light from the reference mirror with an optical multiplexer, and analyzes the interference light The tomographic image is generated.

Conventionally, as described in Patent Document 1, for example, when imaging the front teeth, the probe mounts a metal direct-view imaging support for the front teeth and abuts the tip of the front tooth support against the front teeth. Shooting is performed in a stable state by causing or locking it.
In addition, when photographing the molars, the probe is a metal for molars provided with a fixture that is placed on the molars and locked to the molars, and an oblique mirror that reflects the measurement light and the scattered light. The imaging is performed by attaching a side view imaging support made in Japan.

FIG. 7 is a schematic view showing a state in which a molar tooth is photographed by a probe attached with a conventional side view photographing support.
As shown in FIG. 7, in the probe 100 used when photographing the molar S 100, the outer ring member 300 provided at the tip of the housing 200 is a support for lateral vision 400 for molars (support for molars) Is attached. The side view photographing support 400 includes an engagement cylindrical member 410 detachably provided in the opening of the outer ring member 300, a rod portion 420 connected to the engagement cylindrical member 410, and a tip end portion of the rod portion 420. There is a diagonal mirror frame 430 joined in a state of 45 degrees diagonally, a diagonal mirror 440 fitted inside the diagonal mirror frame 430, and an annular fixing tool 450 horizontally attached to the lower end of the diagonal mirror frame 430; Is configured.

  The fixture 450 is placed on the molar S100 when photographing the molar S100 with the probe 100, similarly to the fixture of the probe of the patent document 1, to prevent the tip of the probe 100 from being shaken and to be stationary. It is a part to The fixture 450 has a height H100 to reduce its weight, to make it easy to operate, to block measurement light during shooting, and not to disturb the surgeon who views the shooting unit. It is formed in the shape of a low and thin circular ring. The height H100 is generally at most about 2 mm.

JP, 2014-61089, A (Figure 10, Figure 12, Figure 14, Figure 16)

  However, when the molar view S100 is captured by attaching the lateral view imaging support described in Patent Document 1 or the lateral view imaging support 400 illustrated in FIG. 7 to the probe, the slit mirror 440 is too close to the surface of the molar S100. Therefore, there is a problem that the image of the extra oblique mirror is reflected in the photographed three-dimensional tomographic image or the two-dimensional tomographic image, and the image becomes difficult to see.

  Therefore, the present invention was invented to solve such a problem, and it is possible to obtain a clear tomographic image by preventing the oblique mirror from being reflected in the tomographic image of the subject to be photographed. The task is to provide.

  In order to solve the above-mentioned subject, a probe concerning the present invention is a probe used for an optical coherence tomography image generating device which irradiates measurement light to a photographic subject, reflects it, and recovers the scattered light which returned. A housing provided with a light path of light, a support attached to the tip of the housing and brought into contact with the subject, a slant mirror disposed at the tip of the support and reflecting the scattered light, and the slant mirror A spacer connected to the lower end portion of the light source and brought into contact with the subject, wherein the height of the spacer sets in advance the distance from the subject to a predetermined reference point on the oblique mirror in the optical interference tomographic image generation device The predetermined reference point is set to a first separation height at the lower end of the oblique mirror.

  According to such a configuration, the probe is separated such that the height of the spacer exceeds the distance from the subject to the predetermined reference point of the oblique mirror by a half of the coherence length set in the optical coherence tomographic image generation device. The oblique mirror is disposed out of the range of the distance which can be photographed by being set to be set. Therefore, since the image of the oblique mirror appears outside the image area, it is possible to prevent the oblique mirror from being reflected in the tomographic image taken by the probe. In addition, the spacer of the support is set to the first separation height with the predetermined reference point at the lower end of the oblique mirror, so that the focal distance from the condenser lens to the subject is taken during shooting of the subject. Since the desired distance can be maintained constant, a clear tomographic image of the subject can be obtained.

  Further, instead of the first separation height, the height of the spacer is set to a second separation height where the predetermined reference point is a lower end portion of the scanning area of the measurement light in the oblique mirror. Is preferred.

  According to this configuration, the height of the spacer is set to a second separation height in which the predetermined reference point is at the lower end portion of the scanning region of the measurement light in the oblique mirror. Because it can be made smaller, the feeling of pressure when the support is put in the mouth can be alleviated.

  Moreover, it is preferable that the height of the said spacer is set to the height between the said 1st separation height and the said 2nd separation height.

  According to this configuration, the height of the spacer is set to a height between the first separation height and the second separation height, thereby eliminating the reflection of the oblique mirror in the photographed tomographic image. can do.

  According to the present invention, it is possible to provide a probe capable of obtaining a clear tomographic image without the oblique mirror being reflected in the tomographic image of the subject to be photographed.

It is a perspective view showing an example of a probe concerning an embodiment of the present invention. It is an enlarged side view showing the tip part of a probe. It is explanatory drawing which shows the range which can be image | photographed with a probe and the range which a diagonal mirror does not appear in an image. It is a figure which shows the 1st modification of the probe which concerns on embodiment of this invention, and is a principal part expansion schematic front view of a support body. It is a figure which shows the 1st modification of the probe which concerns on embodiment of this invention, and is a principal part expansion schematic side view of a support body. It is a figure which shows the 2nd modification of the probe which concerns on embodiment of this invention, and is a principal part expansion perspective view of a support body. It is a principal part enlarged side view which shows the probe provided with the conventional support body for side view imaging | photography.

  Next, an example of a probe according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. Before describing a probe according to an embodiment of the present invention, an OCT apparatus (optical coherence tomographic image generation apparatus) in which the probe is used will be described. Hereinafter, as an example of the subject S which is an intraoral tissue to be diagnosed of a dental patient photographed by an OCT apparatus (optical coherence tomographic image generation apparatus), a molar (a posterior tooth portion) will be described as an example.

<OCT device>
The OCT apparatus (not shown) is a tomographic imaging apparatus that captures the subject S, which is an intraoral tissue, using the coherence of light. The OCT apparatus mainly includes a probe 1 (diagnosis probe unit), an optical unit, and a control unit.
The OCT apparatus distributes, within the optical unit, laser light emitted from a light source to measurement light to be applied to the subject S and reference light to be applied to a reference mirror. The measurement light is irradiated to the subject S, and the scattered light returned from the inside of the subject S and scattered is recovered by the probe 1. Also, the scattered light is illuminated by the reference mirror in the optical unit. Then, the scattered light and the reflected light from the reference mirror are combined by the optical unit by the optical multiplexer, and the interference light is analyzed by the control unit to generate an optical interference tomographic image.

<Probe>
The probe 1 shown in FIG. 1 includes scanning means (galvano mirror or MEMS mirror) for scanning laser light, guides laser light from the optical unit to the subject S (see FIG. 2), and scatters in the subject S. And receive the scattered light reflected and guide it to the optical unit. The probe 1 includes a housing 2 in which optical paths of measurement light and scattered light are provided, and a support 3 attached to the tip of the housing 2.

  At the time of photographing, the operator holds the housing 2 by hand and places the tip of the support 3 for side-view photographing (for molar teeth) on the subject S of the patient so as to prevent camera shake etc. Let Then, the measurement light introduced into the housing 2 from the optical unit via an optical fiber (not shown) or the like is irradiated to the subject S from the distal end opening 2 a of the housing 2. Further, the scattered light reflected and returned from the inside of the subject S is collected at the distal end opening 2 a of the housing 2 and transmitted to the optical unit.

<Housing>
The housing 2 shown in FIG. 1 comprises a substantially straight hollow resin case. In the housing 2, a lens housing portion 2 b for housing the condenser lens 4 is formed at the tip end portion, and an optical fiber and a cable (not shown) and the like are inserted at the base end portion. The axial middle portion of the housing 2 is a portion which the operator holds by hand and the scanning means is accommodated, and is formed in a substantially rectangular shape in a longitudinal sectional view.

The tip end opening 2a is a portion to which the support 3 is attached, and is formed of an opening formed in a circular shape at the tip end of the lens housing portion 2b. The tip end opening 2 a is also a site for irradiating the subject S with the measurement light from the scanning means in the housing 2 through the support 3 and collecting the scattered light reflected by the subject S. The distal end opening 2 a is provided with a cylindrical body 21 in which a support mechanism (not shown) for detachably holding the mounting portion 31 of the support 3 is provided.
The lens housing portion 2 b is formed in a substantially circular cylindrical shape in cross section.

  The shape of the housing 2 is not particularly limited as long as the housing 2 has the tip end opening 2 a to which the support 3 is attached. For example, the housing 2 is formed in a substantially inverted L shape (substantially pistol shape) in a side view, a central portion thereof in a substantially bent shape in a side view, or the lens housing 2b side And the grip portion side may be formed in a state of being bent downward, or the like.

  The cylindrical body 21 is a member for detachably attaching the mounting portion 31 of the base end side of the support 3 for direct view imaging, and is formed in a substantially cylindrical shape. Inside the cylindrical body 21, a mounting and demounting mechanism (not shown) for mounting the mounting portion 31 detachably and rotatably is provided.

<Condenser lens>
As shown in FIG. 2, the condensing lens 4 is a lens that condenses the scanning light by the scanning means and condenses the measurement light on the subject S and irradiates it with the object S in the direction of the optical axis in the lens housing 2b. Position adjustment is possible.

<Support>
The support 3 keeps a constant distance between the subject S and the condenser lens 4 when capturing a tomographic image of the subject S, and supports the probe 1 in a stable state without swinging the subject S with respect to the subject S. It is a member for In addition, since the support 3 is for the molars (for side view photography), the support 3 is provided with the oblique mirror 34 for reflecting the measurement light and the scattered light in the direction orthogonal to the optical axis. The subject S can be photographed from the orthogonal direction. The support 3 is disposed at the distal end of the housing 2 and extends in the optical axis direction from the vicinity of the distal end opening 2a for collecting scattered light, and is used in contact with the subject S.

  The support 3 includes a mounting portion 31 provided detachably at the tip end opening 2 a, a rod-like portion 32 extended in the optical axis direction, and a steric mirror holding portion 33 connected to the tip of the rod-like portion 32. An oblique mirror 34 provided in the oblique mirror holding portion 33 and a spacer 35 connected to the lower end of the oblique mirror holding portion 33 and brought into contact with the subject S are provided. The support 3 is entirely formed of a metal such as stainless steel and integrated by welding or the like.

The mounting portion 31 is removably (replaceable) and rotatably mounted to the distal end opening 2 a of the housing 2. The mounting portion 31 is formed in a substantially cylindrical shape.
The rod-like portion 32 is a thin round rod-like member extending in parallel along the optical axis. The base end of the rod-like portion 32 is joined to the upper end of the mounting portion 31, and the tip end is formed by bending downward at 45 degrees and forming the upper end of the oblique mirror holding portion 33 (upper back surface It is joined to). The rod-like portion 32 is an intermediate member interposed between the housing 2 disposed outside the mouth of the dental patient at the time of photographing and the oblique mirror 34 and the spacer 35 disposed in the mouth of the dental patient .

The oblique mirror holding portion 33 is a substantially disk-shaped member provided with an oblique mirror 34 on the surface on the housing 2 side, and is arranged with the oblique mirror 34 in an inclined state at 45 degrees so that the tip side is lowered.
The oblique mirror 34 is made of a metal mirror such as stainless steel and is, for example, formed in a circular shape.

  The spacer 35 is a means for arranging the oblique mirror 34 at a position where the image of the oblique mirror 34 is not reflected, in order to eliminate the appearance of the image of the oblique mirror 34 in the image taken by the probe 1. The spacer 35 serves to keep the distance between the oblique mirror 34 and the subject S constant at a distance at which the image of the oblique mirror 34 appears outside the image area by being disposed between the oblique mirror 34 and the subject S at the time of photographing. In addition, the spacer 35 functions to support the tip of the probe 1 in a stable state by suppressing contact with the subject S when shooting and thereby shaking the image captured by the probe 1. It also fulfills. Therefore, the height H of the spacer 35 is set so as to separate the distance from the subject S to the predetermined reference point B in the oblique mirror 34 beyond the image captureable distance C set in advance in the optical coherence tomographic image generation device. Is set to a first separation height H1 where the predetermined reference point B is at the lower end 34a of the oblique mirror 34.

  The spacer 35 is connected to the upper end of the upper frame 35a connected to the lower end of the oblique mirror holding portion 33, the support frame 35b extending downward from the upper frame 35a, and the lower end of the support frame 35b, and abuts on the subject S. Lower frame 35c and a window 3d made of space.

The upper frame 35a is made of, for example, a circular ring-shaped member disposed horizontally. The upper frame 35 a has a front end portion joined to the lower end portion of the oblique mirror holding portion 33.
The support frame 35 b is, for example, a member formed between the circular upper frame 35 a and the circular lower frame 35 c to connect the both. The support frame 35 b is vertically provided in the vertical direction at three locations between the upper frame 35 a and the lower frame 35 c with an equal interval.
The lower frame 35c is a part to be placed on the subject S, and has, for example, the same round ring shape as the upper frame 35a.

The window portion 35 d is a space for making the spacer 35 easy to perform an imaging operation by suppressing the hiding of the object S by the spacer 35 when the operator views the object S during imaging. The window portion 3d is formed of three support frames 35b arranged at equal intervals, an upper frame 35a, and a lower frame 35c.
The spacer 35 thus formed has three windows 35 d for visual recognition on the side, and the whole is formed in a hollow cylindrical shape through which the measurement light and the scattered light pass in the vertical direction. .

Next, the area A and the imageable distance C to be imaged will be described with reference to FIG. FIG. 3 is an explanatory view showing an area which can be photographed by the probe and an area where the oblique mirror does not appear in the image.
The shootable distance C shown in FIG. 3 is a shootable distance (depth distance) in the depth direction from the surface of the subject S, and is set in advance as a design specification from the use of the optical interference tomographic image generation apparatus.

  Further, to give an example, the light source of the OCT apparatus has a frequency (e.g., 250 MHz) defined for use in the measurement of an optical coherence tomographic image of a predetermined depth which is a shootable distance C specified by the light source manufacturer. The optical path length (for example, 10 mm) of the optical path adjustment unit of the clock optical interferometer is set and shipped in the factory of the light source manufacturer in order to generate the signal of.

  As described above, the shootable distance C of the light source used in the OCT apparatus is generally preset by the light source maker at the time of maker shipment. In some cases, a frequency converter or the like may be provided outside the light source to change the shootable distance C.

  As shown in FIG. 3, the coherent distance L (coherent length) is a round trip distance until the measurement light having entered the object S is reflected at a predetermined depth and returned as scattered light. The coherence length L corresponds to a distance at which the attenuation of the power spectrum is 6 dB, and a high coherence of 10 m or more and less than 48 mm is preferable. Therefore, in the present invention, a laser light source for the SS-OCT system, in which the coherence length L is 16 mm, is adopted. In that case, the imageable distance C is the area A to be imaged by the probe 1 and is 8 mm, which is a half of the coherent distance L. The image obtained at this time is an image (inverted image) in which the subject S faces the image, but it is possible to obtain an image that is not inverted by soft inversion.

Therefore, the height H1 of the spacer 35 shown in FIG. 2 is 8 mm, which is the same height as the imageable distance C which is the length of the area A to be imaged when imaged by the probe 1. The imaging possible distance C with the probe 1 is 8 mm from the surface of the subject S and is a half distance of the coherence length L.
With this configuration, it is possible to prevent the image of the oblique mirror 34 from being reflected in the light interference image of the subject S.

[Effect]
Next, the case of imaging the subject S using an OCT apparatus (optical coherence tomographic image generation apparatus) will be described.

  As shown in FIG. 2, when the probe 1 captures an image, the distance (focusing point) between the focusing lens 4 and the subject S brought into contact with the lower end (tip) of the spacer 35 is the housing 2. By adjusting with the condensing point adjustment mechanism (not shown) provided internally, the tomographic image to be photographed is adjusted in the depth direction from the surface serving as the reference of the subject S, and the tomographic image extends over a wide range in the depth direction. You can get an image.

  For example, when the focal point of the condenser lens 4 is at the tip of the surface of the subject S, the lower end 35e of the spacer 35 is used to capture a tomographic image at a position P on the middle side of the distance L1 from the surface of the subject S Is pressed against the subject S, and the focusing lens 4 is moved in the direction of the optical axis by the focusing point adjustment mechanism (not shown) until the area A to be imaged within half the coherent distance L Focusing is achieved by adjusting the focus position to the position P. For this reason, it is possible to capture a tomographic image of the position P where the subject S is to be captured in a clear state.

  As described above, the height H of the spacer 35 separates the distance from the subject S to the predetermined reference point B of the oblique mirror 34 so as to exceed the shootable distance C preset in the optical coherence tomographic image generating apparatus. The predetermined reference point B is set to a first separation height H1 at the lower end 34a of the oblique mirror 34. Therefore, the spacer 35 is disposed between the oblique mirror 34 and the subject S, and the oblique mirror 34 is disposed apart from the position where the image of the oblique mirror 34 itself is not reflected. Light interference image can be prevented from being reflected.

  In addition, the support 3 can freely change the direction (the direction of photographing) of the oblique mirror 34 and the spacer 35 about the optical axis in the lens housing 2b by rotating the mounting portion 31 360 degrees. The tomographic image of the molar part in the back of the oral cavity can be easily taken.

  In addition, the support 3 for side view imaging may be an intraoral tissue imaging, a support for direct view imaging, for example, an occlusal surface of the molar portion, a side surface of the tongue, a side of the buccal surface, and the like; It is also suitable for taking a tomographic image of the side of the tongue.

First Modification
The present invention is not limited to the above embodiment, and various modifications and changes are possible within the scope of the technical idea, and the present invention extends to the modified and changed inventions. Of course. In addition, the structure already demonstrated attaches the same code | symbol and abbreviate | omits the description.
FIG. 4 is a view showing a first modified example of the probe according to the embodiment of the present invention, and is an enlarged schematic front view of a main part of a support. FIG. 5 is a view showing a first modified example of the probe according to the embodiment of the present invention, and is a main part enlarged schematic side view of a support. In FIG. 4 and FIG. 5, although the scanning area D is illustrated as having a thickness for illustration so that its position can be seen in a side view, it has no thickness in practice.

  In the embodiment, the case where the predetermined reference point B is set to the first separation height H1 in which the lower end portion 34a of the oblique mirror 34 is set has been described, but the position of the predetermined reference point B is changed I don't care. The predetermined reference point B may be a reference point B1 which is the lower end of the scanning area D of the image reflected on the oblique mirror 34, as shown in FIG.

  For this reason, the height H of the spacer 35 described in the above embodiment is set to the lower end portion of the scanning region D of the measurement light in the oblique mirror 34 instead of the height H1 of the first separation. It may be set to the second separation height H2. That is, the height H of the spacer 35 may be set within the range of height between the first separation height H1 and the second separation height H2.

  For this reason, as shown in FIG. 5, when the scanning region D in the oblique mirror 34 is at a lower position, the second separation height H2 is the second separation height from the first separation height H1. The height H2d 'may be in the range of height between H2. As an example, the scanning area D is a square having a length of 10 mm in length and width. The second separation height H2 is 8 mm.

  In this manner, the oblique mirror 34 sets the reference point B1 at the lower end of the scanning area D in the oblique mirror 34 and separates the second separation height H2 (for example, 8 mm) from the reference point B1 to the subject S It may be set as In this way, the image of the oblique mirror 34 itself can be prevented from being reflected in the tomographic image.

  The oblique mirror 34 is not limited to a circular one, and may be a square such as a square according to the shape of the scanning area D, or may be a polygon such as a regular hexagon or an octagon. .

Second Modified Example
FIG. 6 is a view showing a second modified example of the probe according to the embodiment of the present invention, and is an enlarged perspective view of the main part of the support.

Although the said embodiment demonstrated and demonstrated the probe 1 provided with the spacer 35 which has the window part 35d as an example as an example of the support body 3, it is not limited to this.
As shown in FIG. 6, the probe 1 may have a support 3A for side-view photography of an angle type to be used in contact with the subject S, as long as the height H of the spacer 35 is present.

  For example, as shown in FIG. 6, the spacer 35A of the support 3A for side view photography is connected to the lower end 34a of the tip end side of the oblique mirror 34A that converts the optical axis of the condenser lens 4 into the orthogonal direction. It may be in the form of In this case, the spacer 35A is formed in a cylindrical shape having an opening at the upper and lower portions, and irradiates the subject S to collect scattered light.

  As described above, the spacer 35A has a shape that can be disposed apart from the oblique mirror 34A and the subject S at a position where the image of the oblique mirror 34A is not reflected in the tomographic image taken, The shape may be changed as appropriate as long as the light and the scattered light can pass through.

[Other modifications]
The rod-like portion 32 of the support 3 may be retractable in the optical axis direction with respect to the housing 2. With this configuration, it is possible to adjust the focal position of the focusing lens 4 and the length of the optical axis.

DESCRIPTION OF SYMBOLS 1 probe 2 housing 3, 3A support body 33 diagonal mirror holding part 34, 34A diagonal mirror 35, 35A spacer A scanning area B, B1 predetermined reference point in diagonal mirror C imageable distance H spacer height H1 first separation Height H2 Second separation height L Coherence distance S Object

Claims (3)

A probe for use in an optical coherence tomographic image generating apparatus for irradiating a subject with measurement light and reflecting and returning scattered light,
A housing provided with an optical path of the measurement light;
A support attached to an end of the housing and brought into contact with the subject;
An oblique mirror disposed at the tip of the support to reflect the scattered light;
And a spacer connected to the lower end of the oblique mirror and brought into contact with the subject,
The height of the spacer is
The distance from the subject to a predetermined reference point on the oblique mirror is set to be separated beyond the image captureable distance set in advance in the optical coherence tomographic image generation device,
Setting the predetermined reference point to a first separation height at the lower end of the oblique mirror;
A probe characterized by Instead of the first separation height, the height of the spacer is
The second separation height in which the predetermined reference point is at the lower end portion of the scanning region of the measurement light in the oblique mirror,
The probe according to claim 1, characterized in that The height of the spacer is
It is set to a height between the first separation height and the second separation height,
The probe according to claim 2, characterized by

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