JP2008194108A - Three-dimensional characteristic measuring and displaying apparatus with positional direction detecting function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable the application of a probe even within a smaller area such as inside of an oral cavity while achieving the collective reviewing of measuring data over a wider range than that of a measuring area measurable by one operation by measuring and calculating the relationship of the relative positional direction between the probe and an object to be measured. <P>SOLUTION: The apparatus has the probe or a positional direction measuring means for measuring the position and/or direction of the specified part arrayed in the object to be measured and carries out a measurement while making the positional direction of the probe move on a fixed track with respect to the object to be measured. Moreover, the moving track data generated in the relative one- to three-dimensional positional directions of the subject to be measured and the probe are arrayed in hourly and spatial synchronization with the one- to three-dimensional reflection characteristic data of the surface and the inside of the object to be measured to acquire the information on the two- to three-dimensional structure, on the composition or on changes in material of the object to be measured or the information on the motions involved. Thus, an optical coherent tomographic apparatus displays tomographic images of mainly the sectional surfaces involved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention measures the surface and internal characteristics of a living organism as characteristic values in a three-dimensional space, performs arithmetic processing on the measurement data in a calculation unit, and displays them on a two-dimensional or three-dimensional screen or printed matter. The present invention relates to a measurement / display device. Specific examples of 3D upper characteristic measurement / display devices include X-ray CT, MRI, 2-3D ultrasound imaging, PET, SPECT, optical CT, and optical coherence tomography However, it is particularly useful for an optical coherence tomography apparatus having a small measurement range per time, an MRI apparatus using a near magnetic field, and a three-dimensional ultrasonic diagnostic apparatus. Further, when a video camera, which is a visible optical imaging device for a two-dimensional surface in a three-dimensional space, is also close, it is useful because the imaging range is narrow. Among these, medical devices that fix a subject and use a probe that can be freely positioned in a three-dimensional space, especially the soft and soft tissue in the oral cavity, which is a dental region, have two to three-dimensional characteristics. It is suitable for applications in which a probe is inserted into the oral cavity for measurement. In addition, the ultrasonic diagnostic imaging apparatus normally measures a two-dimensional cross section, but is particularly useful when moving this in a direction perpendicular to the cross section. In addition, the optical coherence tomography apparatus has a narrow measurement range of several mm to several tens of mm, and is particularly useful for applications such as application to dentistry.

Conventionally, an X-ray imaging apparatus, an intraoral camera, a dental camera, X-ray CT, MRI, and the like have been used for imaging a jaw and mouth region in dental diagnosis. Recently, inventions that apply optical coherence tomography to dentistry have been devised.
The image obtained by the X-ray imaging apparatus is a transmission image to the last, and the information on the X-ray traveling direction of the measurement object is superimposed and detected. Therefore, it is impossible to know the internal structure of the measurement object three-dimensionally. Also, because X-rays are harmful to the human body, the annual exposure dose is determined, and only qualified surgeons can handle the device, and only in rooms surrounded by shielding materials such as lead and lead glass. I can not use it.

Since the intraoral camera images only the surface of the intraoral tissue, internal information such as teeth cannot be obtained. X-ray CT is harmful to the human body as well as an X-ray imaging apparatus, has low resolution, and is large and expensive. Ordinarily used MRI apparatuses have poor resolution, the apparatus is large and expensive, and the internal structure of teeth without moisture cannot be imaged.
By the way, an optical coherence tomography apparatus (hereinafter referred to as an OCT apparatus) is harmless to a human body and can obtain three-dimensional information of a measured object with high resolution. ing. Note that OCT is an abbreviation for Optical Coherence Tomography. Further, the optical coherence tomography apparatus is sometimes called an optical coherence tomography apparatus. Also in the dental field, inventions that apply optical coherence tomography devices have been made. (See Patent Documents 1 to 4, Utility Model Documents 1 to 4, Non-Patent Documents 1 to 10)

Here, in order to show how the measurement range of the OCT apparatus is configured, the basic configuration will be described.
(Basic configuration of OCT system, explanation of basic terms and operating principle)
An embodiment of a dental optical coherence tomography apparatus according to the present invention will be described with reference to FIG. In FIG. 1, a temporally low coherent or coherent light source 1, a fiber coupler 2a (light splitting unit / interference unit), a reference mirror 3, a photodetector 4 (light detecting unit), and a computer 5 (calculating unit). ) Is shown as the basic configuration of OCT.
In this basic configuration, light from the light source to the fiber coupler is light source light, light from the fiber coupler to the reference mirror, reflected from the reference mirror and returned to the fiber coupler again, reference light, and light from the fiber coupler to the object T to be measured The measurement light and the light reflected from each part of the measurement object T and returning to the fiber coupler are referred to as z-direction object reflection light, and the light from the fiber coupler to the light detector 4 and the light source 1 is referred to as interference light.

  In this basic configuration, the light source light emitted from the light source reaches the fiber coupler and branches into two systems of reference light and measurement light. The reference light is specularly reflected by the reference mirror 3 and returns to the fiber coupler, and the measurement light is measured. Reflected / scattered / transmitted action from each part of the body, backscattered light as a part thereof is reflected as z-direction object reflected light in each part of the measured object T (in the basic configuration, each measured object in the z direction converted on the time axis) ) While returning to the fiber coupler again. The reference light returning to the fiber coupler and the z-direction object reflected light interfere with each other by the fiber coupler, and are branched and emitted toward the light source 1 and the photodetector 4 as interference light. The intensity of the interference light is detected by the photodetector 4, the interference light intensity is input to the computer 5 and measured and analyzed on the time axis, and the backscattering coefficient information of each part of the object, that is, the information of each part of the object is displayed. is there. The reflected light in the z direction carries object information on the waveform as an electromagnetic wave, but the optical waveform is too fast to detect and there is no photodetector that can be measured directly on the time axis, but it interferes with the reference light. By doing so, the backscattering characteristic information of each part of the measurement object is converted into a change in light intensity, so that detection on the time axis is possible with the photodetector.

  For convenience of explanation, the direction in which the measurement light travels is the z direction, the operation for obtaining the data at the center point of the interference where the optical path difference between the measurement light and the reference light is zero, and the operation for obtaining the linear data in the z direction. The operation of obtaining tomographic data of a two-dimensional cross section in the A mode, the z direction and the x direction perpendicular thereto is performed in the B mode, and further, the position of each tomographic slice in the B mode is shifted to obtain three-dimensional data in the z direction, x direction, and y direction. The operation is set to C mode, and the coordinate system of these measured objects is defined as shown in FIG. In order to obtain information in each of the z, x, and y directions, the conventional example of FIG. 1 uses galvanometer mirrors 8-1-2 for scanning the measurement light beam in the x and y directions. Means for obtaining information in the z-axis direction include a reference mirror driving method (so-called time domain method) for driving the reference mirror 3 in the optical axis direction, and a z-axis direction by placing a diffraction grating on the output side of the lens 7-6. Time axis information is converted into spatial axis information in the diffraction direction of the diffraction grating, and a one- to two-dimensional image sensor such as a CCD is used as the photodetector 4, and the time axis information, that is, the z-axis direction information is reproduced on the computer 5. There is a spectral domain method (one of the Fourier domain methods) to be configured, and a swept source method (one of the Fourier domain methods) that uses a variable wavelength light source as the light source 1 and does not use a diffraction grating.

  In addition to the basic configuration of OCT using the fiber coupler 2a, optical fibers 6-1 to 4 used for input / output of light to / from the fiber coupler, collimating or condensing light source light / reference light / interference light. The lenses 7-1 to 5 and 7-7 and the objective lens 7-6 for collecting the measurement light and collimating the z-direction object reflection light are required. A configuration using a beam splitter 2b (not shown) instead of the fiber coupler is also conceivable. In this case, although the optical fibers 6-1 to 4 are not necessarily required, the light source 1, the beam splitter 2b, the reference mirror 3, the objective lens 7-6, and the photodetector 5 need to be optically appropriately disposed and are compact. Although mirrors are used in various places for arrangement, etc., or optical fibers are partially used in some cases, the basic configuration is only the difference between using a fiber coupler 2a or a beam splitter 2b as a member that causes interference. The principle configuration is the same.

  A unit including at least a measurement light and a z-direction object reflected light guiding unit and an objective lens 7-6 is a probe unit U2, at least a light source control output / input from a light detector 4 and a computer 5. The unit including the PC unit (PC Unit) U3, and the unit including at least the light source 1, the fiber coupler 2a, the reference mirror 3, and the light detector 4 are referred to as an OCT unit (OCT Unit) U1.

  In the above-described conventional example based on FIG. 1, in order to obtain the A mode in the z direction, the time domain method uses scanning of the reference mirror in the light beam direction. The Fourier domain method uses inverse Fourier transform of data for each wavelength of the light source. Regarding the B mode and C mode in the x direction and the y direction, scanning with a galvano mirror was introduced, but various methods for realizing these modes have been proposed. For example, in addition to the z-direction A mode by reference mirror scanning, a point light beam from a point light source is obtained as a linear light beam by a cylindrical lens to obtain an x-direction B-mode image (cylindrical lens system), and further combined with y-direction scanning by a galvano mirror. Obtaining C mode is one way to do this. In this method, the Fourier domain method with a fixed reference mirror may be combined with the realization of the A mode. Further, as a special method using a cylindrical lens, a special method for obtaining x-direction line data or xy-direction surface data by performing only x-direction and y-direction galvanometer mirror scanning without using depth direction scanning or Fourier domain method. Different modes are possible. Furthermore, the light from the light source is spread in a two-dimensional plane using a lens, the subject is irradiated with a surface measurement light beam using an aerial optical system, and the xy plane inside the measured object has the same optical path length as the reference mirror. A special mode using the full-field method for obtaining upper data (specifically, a spherical surface close to the xy plane) and a special C-mode operation in which this is combined with A-mode scanning of a reference mirror are also possible.

  With such an OCT apparatus, a high-resolution image inside the measurement object can be obtained in a non-destructive and non-contact manner. Useful applications have been announced from general objects to living bodies, human bodies, medical use, ophthalmology / dermatology / endoscopy / dental fields. Regarding the application of the OCT apparatus to the field of dentistry, examples in which a tomogram of a tooth is photographed using the OCT apparatus are disclosed (for example, Patent Documents 1 to 4, Utility Model Documents 1 to 4, Non-Patent Document 1). 10).

Patent Documents 1 to 3 describe how to incorporate optical coherence tomography into conventional dental equipment when applying it to dentistry, and also hold the position of a probe for measurement using an optical fiber cable or power / signal line. And how to make the direction free, especially how to scan in the depth direction within the probe, and how to emit measurement light from the probe. Patent Document 4 discloses Fourier domain optical coherence tomography that scans the wavelength of a light source, and mentions the wavelength range, the configuration of the probe, and the like. Further, for utility model documents 1 to 4, proposals have been made to incorporate a probe into a dental handpiece. In addition, Non-Patent Documents 1 to 10 report on imaging performance when optical coherence tomography is applied to dentistry.
These optical coherence tomography devices used for dental applications are all applied to dentistry in practical use or research and development announcements other than dentistry including ophthalmology, and the basic configuration described above is the same. is there.
As described above, the prior art has been described for the optical coherence tomography apparatus. However, in the case of the two-dimensional ultrasonic diagnostic imaging apparatus, the probe is moved in the direction when imaging a cross section continuous in a direction perpendicular to the two-dimensional imaging cross section. It is usual to move to. In addition, the imaging range will be limited in applications where a probe is inserted into the oral cavity to observe a tomographic image of soft tissue in the oral cavity. Also, an endoscope type MRI apparatus that uses a near magnetic field has a limited measurement range both when used as an endoscope and when used in the oral cavity.

JP 2004-344260A JP 2004-344262A JP 2004-347380A JP 2006-191937 A Utility model registration No. 3118718 Utility model registration No. 3118823 Utility model registration No. 3118824 Utility model registration No. 31188839 Laser Research October 2003 Issue: Technology Development of Optical Coherence Tomography Centered on Medical Care Journal ofBiomedical Optics, October 2002, Vol.7 No.4: Imaging caries lesions and lesion progression withpolarization sensitive optical coherence tomography APPLIED OPTICS, Vol.37, No.16, 1 June 1998: Imaging of hard-and soft-tissue structure In theoral cavity by optical coherence tomography OPTICS EXPRESS, Vol.3, No.6,14 September 1998: Dental OCT OPTICS EXPRESS, Vol.3, No.6,14 September 1998: In vivo OCT Imaging of hard and soft tissue of the oral cavity Proceedings of 2004 Annual Meeting of the Optical Society of Japan, 5aF6, Dental Sample Measurement by Fourier Domain Optical Coherence Tomography 2005 Annual Meeting of the Optical Society of Japan, 24pE5, Application of Spectral Coherence Tomography to 3D Dental Measurement Photonics West2006, 6079-66, In-Vivo three dimensional Fourier-Domain Optical Coherence Tomography for soft and hard oral tissue measurements Photonics West2006, 6137-03, Assessment of dental-caries using optical coherence tomography Journal ofDental Research 85 (9) 2006, Remineralization of Enamel Caries Can Decrease Optical Reflectivity

In the optical coherence tomography device, which is a typical configuration of these conventional three-dimensional characteristic measurement / display devices, in order to obtain information in each of the x, y, and z directions as described above, the x direction and the y direction are used. The galvanometer mirrors 8-1 and 2-2 for scanning the measurement light flux are used. Moreover, it is necessary to scan the measurement light beam in the y direction simply to obtain information in each of the y and z directions. The method using a cylindrical lens also requires one-dimensional galvanometer mirror scanning to obtain a C-mode image. For this reason, a very small probe is required in the measurement from the molar part and the lingual side of the tooth where the probe needs to be inserted particularly in the back of the oral cavity.

On the other hand, the galvano mirror is a set of motors for driving the galvano mirror, and it is currently large enough to be inserted into the oral cavity, and optical coherence tomography is used in fields such as dentistry. It becomes a big obstacle. Further, not only the size but also the weight of the galvanometer mirror is a heavy burden on the operator. For this reason, since the probe cannot be brought into the oral cavity, for example, when measuring the lingual side surface of the molar part, the distance from the galvanometer mirror to the subject becomes very long, and the design is difficult and the design can be made temporarily. However, it also causes performance degradation such as resolution, measurement depth, and artifacts. In addition, if the probe is heavy, it is necessary to fix it to the measurement object by some method at the time of measurement. However, as a fixing method, it is very difficult to maintain a fixed position direction with respect to the measurement object by hand. .

In the current OCT (general optical coherence tomography) performance, a measurement speed of 30 frames per second is realized in the B mode, but it takes several seconds to several tens of seconds in the C mode. It is almost impossible to maintain. As a countermeasure, for example, in the case of dentistry, there is a method in which a patient bites a mouthpiece or a cine is fixed to a tooth and the mouthpiece or cine is fixed to a probe (Japanese Patent Application No. 2005-337372). Then, the burden on the operator's arm becomes heavy or the burden on the patient's jaw or dentition becomes heavy, which hinders measurement. Patent Documents 1 to 3 disclose a type in which the probe portion is supported by an articulated arm like an intraoral X-ray apparatus, but this disclosure shows a method for fixing the probe to a subject. If there is no fixation, it is difficult not only to position the subject precisely, but also in the case of C-mode imaging that takes several tens of seconds, the probe fixed by the articulated arm vibrates or the patient moves. It can also cause disturbances and artifacts. Therefore, the present invention has an object to be solved by providing a method for firmly fixing a probe to a subject without moving the patient from the treatment chair and without burdening the operator or the patient. Therefore, it is an object to be solved to provide a dental coherence tomography apparatus that is easy to handle by reducing the size and weight of the probe and that does not cause deterioration in performance by allowing the probe to be brought into the oral cavity as needed.

Further, even when the galvanometer mirrors 8-1 and 2-2 are used to scan the measurement light beam in the x direction and the y direction, the scanning system measurement range is very limited, and the range of several mm to several tens mm is available. It is the limit. For this reason, in a wide range of measurement applications in which all dentitions in dentistry are collectively measured, there is a problem that a region exceeding the scanning system measurement range becomes a plurality of measurement data that are not spatially related to each other. In the full-field method, a galvanometer mirror is unnecessary, but in this method as well, the measurement range is limited to a range in which measurement light can be irradiated with a lens. When the measurement position is changed by moving the probe, there is no means for commonly grasping the three-dimensional position of the measurement data after the movement and the measurement data before the movement. Therefore, with the current measurement range performance of several tens of millimeters × ten of tens of millimeters × depth of several millimeters, it is impossible to measure and display the entire teeth and periodontals, or to display the dentition of the entire upper and lower jaws. Therefore, it is a problem to be solved to display and measure the entire tooth and periodontium with reference to the same position direction and to display the dentition of the entire upper and lower jaws. In the above, the optical coherence tomography apparatus, which is a kind of three-dimensional characteristic measurement / display apparatus, has been described. This is a general example of a three-dimensional characteristic measurement / display apparatus having a narrow measurement range, particularly a two-dimensional ultrasonic image. The same applies to a diagnostic apparatus and an endoscope type MRI apparatus.

The basic means for determining the present invention includes a position / direction measuring means for measuring either or both of the position / direction of a specific part arranged on the probe or the measured object, Measurement is performed while the position direction of the probe moves along a fixed trajectory, and the three-dimensional upper characteristic measurement / display device, in particular, the first to third dimensional reflection characteristic data on the surface of the measurement object and the inside by the optical coherence tomography device, and the position direction measuring means By measuring the measurement data in synchronization with time or by moving the probe along a fixed trajectory, relative 1 to 3D position / direction data of the measurement object and the probe is generated, and the measurement object By arranging the surface and internal 1-3 dimensional reflection characteristic data in spatio-temporal synchronization, 2 to 3 dimensional structure information or composition information of the measurement object or To obtain the quality change information, or a motion information is to display or print the tomogram mainly these cross.
Furthermore, it is to constitute and use one or a plurality of angular velocity sensors or acceleration sensors as the position direction measuring means.
Further, the position / direction measuring means is a linear gauge or angle gauge for measuring a relative position / direction of the probe and a stationary stationary part fixed or stationary with respect to the measurement object, or an optical marker and The construction and use of a set of position detectors, optical markers or image sensors, or optical markers or optical coherence tomography devices themselves.
Further, the image sensor or the optical coherence tomography device derives position / direction data of a specific optical marker or a characteristic pattern of the measured object from the measured object data detected by itself.
Further, a part or all of the measurement object or any of the probes is stationary. One of all or a part of the measurement object or the probe is stationary. Among all the data of the three-dimensional characteristic measurement / display device, especially the optical coherence tomography device, which are measured in synchronization and arranged synchronously in time and space, multiple measurement data exist in the range of the desired resolution. If so, replace them with a single piece of appropriate data.
The overlapping data is replaced with an average value or an approximate value based on the least square method of the data in the desired resolution range or the surrounding area.

All of the position and direction detection methods according to the present invention can be realized by using components that are considerably smaller and lighter than the galvanometer mirror, and the probe can be miniaturized by eliminating or reducing the galvanometer mirror in optical coherence tomography. It enables measurement with good operability in a very small space like dentistry. Regardless of scanning with a galvanometer mirror, a wide range of two- to three-dimensional structure information or composition information, material change information, or movement on the surface / inside of the measurement object such as the entire dentition including periodontal tissue An optical coherence tomography apparatus that obtains information and displays or prints tomographic images mainly of these cross sections is realized. These are not limited to optical coherence tomography devices, but are also applicable to all three-dimensional upper characteristic measurement / display devices with a narrow measurement range, particularly to two-dimensional ultrasonic image diagnosis devices and endoscope-type MRI devices.

  As the best mode for carrying out the present invention, optical coherence tomography will be described as an example. The entire object to be measured is fixed stationary, and the relative position and direction of the specific part of the probe and the object to be measured are measured based on the data of the specific part measured by optical coherence tomography itself as the position and direction measurement means. The relative 1 to 3 dimensional position-direction motion trajectory data of the measurement object and the probe and the 1 to 3 dimensional reflection characteristic data of the measurement object surface and the inside are synchronized in spatio-temporal manner in a 2 to 3 dimensional manner. Structure information, composition information, material change information or their movement information, and replace multiple measurement data that overlap in the desired resolution range with average values or approximate values based on the least squares method. An optical coherence tomography apparatus that displays or prints a tomographic image mainly having a cross section will be described with reference to FIGS.

  FIG. 2 is a conceptual diagram for explaining the entire embodiment. The measurement light guided by the optical fiber cable 6-3 is irradiated to the measurement object through the objective lens and the galvano mirror driven in the y-axis direction, and is reflected backscattered. It shows that the light is again incident on the optical fiber through the galvanomirror / objective lens and guided to the OCT unit U1 through the optical fiber cable 6-3. In this example, the galvanometer mirror for scanning in the x-axis direction is not necessary due to the effect of the present invention. FIG. 2 shows a tooth as an example of a measurement object, and further shows a cross-section line of a surface, a caries cross-section and a crack cross-section as an internal structure / lesion as an example of the cross-section thereof. In this embodiment, it is assumed that the measurement part moves by moving the probe, and the measurement cross-sectional areas at the probe position A and the probe position B are shown in the tooth portion.

FIG. 3 shows the tomographic images of the measurement results of the measurement cross-sectional areas at the probe position A and the probe position B, respectively, as square frames. Actually, the position direction of the two images shifts in a six-dimensional manner including an angle, but the drawing illustrates a two-dimensional transition in the y direction and the z direction. In the state of the raw data of optical coherence tomography, these two image data are mutually independent data having no spatial positional direction relationship. However, in the figure, as a result of the implementation of the present invention, the two image data covers the two images. The continuous area of the measurement object is displayed superimposed. In the present embodiment, the following method is used as an example for overlapping continuous regions.
1. Feature planes with the shapes shown in the figure from the data of the two measurement areas (example: planes extracted as continuous areas depending on the intensity level, planes surrounded by feature lines) and feature lines (example: feature planes) Boundary, line connecting the points perpendicular to the direction where the intensity changes suddenly, line connecting by the characteristic points) and characteristic points (eg points where the intensity changes suddenly, points where the direction of the characteristic line changes abruptly) Extract.
2. Move and rotate the relative position directions of the two measurement areas in a six-dimensional manner to find the movement amount and the rotation amount so that the feature points, feature lines, and feature planes of the two regions coincide. Depending on the relationship between the probe moving direction and the time required to acquire one tomographic data, the two measurement regions may be regarded as being moved in parallel, and this may be processed by two-dimensional movement.
3. Two measurement data are arranged in a six-dimensional position / direction in the three-dimensional space according to the found movement amount and rotation amount so that the data of the continuous regions of the measurement object corresponding to the two measurement regions are overlapped. Processes 1 to 3 are performed for all measurement regions.
4). Of two sets of measurement data arranged in space and time, replace the data where multiple measurement data overlap in the desired resolution range with the average value, and also spatially close the measurement area An approximate value based on the least square method is calculated from the average values of a plurality of sets of and the average value is replaced with this.
In the present embodiment, an example in which data of optical coherence tomography itself is used as a position / direction detection unit has been described. However, common feature points / feature lines from simultaneous images of a plurality of image sensors from different angles fixed to a probe are shown. There is also a method of extracting a feature surface and finding a relative positional direction relationship between the measured object and the probe based on the principle of the range finder. Further, there is a method of finding the positional direction relation between the measured object and the probe from the image including the measured object and the probe of the plurality of image sensors not fixed to both the probe and the measured object.
(Second embodiment)
FIG. 4 shows an example in which the position / direction measuring means is three acceleration sensors and three angular velocity sensors. In FIG. 4, a three-direction acceleration sensor and a three-direction angular velocity sensor are fixed to the probe with respect to the configuration of FIG. 2, and the measured object is stationary or moving at a constant speed with respect to the earth (such as the rotation of the earth). It is assumed that astronomical motion is negligible. In such a configuration, the output of the angular velocity sensor and acceleration sensor and the output data of optical coherence tomography are acquired synchronously while moving the probe. By determining an appropriate initial value and calculating the relative position direction of the probe and the measured object by integrating the output of the acceleration sensor twice in time and integrating the output of the angular velocity sensor once in time. Each data of optical coherence tomography acquired in time synchronization is arranged on the coordinate system of the measurement object.
For linear gauges or angle gauges, linear gauges and angle gauges are installed between the mounting part fixed to the object to be measured and the probe, and the relative position and direction of the probe and the object to be measured are calculated from these outputs. .
Furthermore, for the mechanical scanning of the probe, the initial position of the probe is determined with respect to a stationary object to be measured, the probe is moved along a constant trajectory, and data of optical coherence tomography is acquired in synchronization with this, The relative position direction of the probe and the measured object is determined in advance.
In any method, it is possible to rearrange the optical coherence tomography data on the coordinate system of the measurement object by knowing the relative position direction of the probe and the measurement object.

The present invention can be used in a field that requires a wide range of image-cutting images in the field of application of optical coherence tomography. It is particularly useful in the medical field. Furthermore, in the field of dentistry, the measurement area of the conventional optical coherence tomography is smaller than one tooth, whereas the present invention measures the whole tooth, the existing tooth or the entire dentition on the same patient coordinate system, It can be rearranged as an image and displayed / printed.
The present invention is not limited to an optical coherence tomography apparatus, but measures the surface and internal characteristics of a living organism as characteristic values in a three-dimensional space, performs arithmetic processing on the measurement data in a calculation unit, and performs a two-dimensional or three-dimensional screen or The present invention is applicable to all three-dimensional characteristic measurement / display devices that display on printed matter. Specific examples of 3D upper characteristic measurement / display devices include X-ray CT, MRI, 2-3D ultrasound imaging, PET, SPECT, optical CT, and optical coherence tomography However, it is particularly useful for an optical coherence tomography apparatus having a small measurement range per time, an MRI apparatus using a near magnetic field, and a three-dimensional ultrasonic diagnostic apparatus. Further, when a video camera, which is a visible optical imaging device for a two-dimensional surface in a three-dimensional space, is also close, it is useful because the imaging range is narrow. Among these, 2 to 3 dimensional characteristics of soft and hard tissues in a medical device such as a dental device where a subject is fixed and can be freely positioned in a 3 dimensional space, especially the dental region Is suitable for such an application that a probe is inserted into the oral cavity for measurement. In addition, the ultrasonic diagnostic imaging apparatus normally measures a two-dimensional cross section, but is particularly useful when moving this in a direction perpendicular to the cross section. In addition, the optical coherence tomography apparatus has a narrow measurement range of several mm to several tens of mm, and is particularly useful for applications such as application to dentistry.

The figure which shows an example of the basic composition of OCT Conceptual diagram for explaining the entire embodiment Tomographic image of the measurement result of the measurement cross-sectional area An example in which the position / direction measuring means is three acceleration sensors and three angular velocity sensors.

Explanation of symbols

1 Light source 2a Fiber coupler (light splitting / interference part)
3 Reference mirror 4 Photodetector (photodetector)
5 Computer (calculation unit)
6-1-4 Optical fibers 7-1-5, 7-7 Lens 7-6 (Objective) lens 8-1-2 Galvano mirror U2 Probe unit U3 PC unit (PC Unit)
U1 OCT unit

Claims (9)

In order to measure at least one-dimensional space characteristics of the measurement object, it has a probe that is a measurement head that can move relative to the measurement object in a three-dimensional space. In a three-dimensional characteristic measurement / display device having a data operation unit that performs data processing,
It has a position / direction measuring means for measuring either or both of the position / direction of a specific part arranged on the probe or the measured object, or the locus of the relative position of the probe with respect to the measured object is determined in advance. A three-dimensional characteristic measurement / display device that performs measurement while moving. 2. The three-dimensional characteristic measurement / display device according to claim 1, wherein the position / direction measuring means is one or both of one or a plurality of angular velocity sensors and acceleration sensors. A linear gauge, an angle gauge, an optical marker, and a position detector for measuring the relative position direction of the probe and the stationary stationary part fixed or stationary with respect to the measurement object. The three-dimensional characteristic measurement according to claim 1, characterized in that it is at least one of the following sets: an optical marker and image sensor set; or an optical marker and three-dimensional characteristic measurement / display device set. -Display device. 4. The positional direction data of a specific optical marker or a characteristic pattern of the measured object is derived from measured object data detected by the image sensor or the three-dimensional characteristic measurement / display device. The three-dimensional characteristic measurement / display device described. The position and direction measuring means measures the time-synchronized measurement data of the surface and to-be-measured object by the three-dimensional characteristic measurement / display device in the first to third dimensions and the measurement data by the position and direction measuring means. The relative 1 to 3 dimensional position-direction motion trajectory data of the measurement object and the probe generated based on the measurement data obtained by the above and the characteristic data on the measurement object surface and the inside of the measurement object in the first to third dimensions are synchronously arranged in time and space. 5. Obtaining 2 to 3 dimensional structure information, composition information, material change information or movement information of the object to be measured, and displaying or printing a tomographic image mainly including these cross sections. 3D characteristic measurement / display device. 6. The three-dimensional characteristic measurement / display device according to claim 1, wherein a part or all of the measurement object or any one of the probes is measured while stationary. 7. All the data of a three-dimensional characteristic measurement / display device, wherein a plurality of measurement data are duplicated in a desired resolution range, and these are replaced with one data. The three-dimensional characteristic measurement / display device described. The overlapping data is replaced with one of the data, or an average value of the data in the desired resolution range or the surrounding area, or an approximate value based on the least squares method. Item 8. A three-dimensional characteristic measurement / display device according to Item 7. A light splitting unit that divides light source light emitted from the light source into reference light that irradiates a reference mirror and measurement light that irradiates the measurement object; and the measurement light reflected by the measurement object and the reference mirror An interference unit that interferes with the reflected reference light to make the interference light, and a light detection unit that measures the interference light. The surface and the inside of the object to be measured are two to three-dimensional based on the measured interference light. Optical coherence that obtains optical backscattering characteristic data, obtains two- or three-dimensional structure information, composition information, or material change information of the measurement object, and displays or prints tomographic images mainly of these cross sections. A tomography device,
In the method in which the light source simultaneously generates a point light beam, a linear light beam, or a surface light beam in a certain wavelength band, a diffraction grating that splits the interference light according to the wavelength between the interference light and the light detection unit and a one-dimensional or two-dimensional light source. In a method in which a light detection unit is formed by an imaging device or the light source temporally scans a point light beam or a linear light beam in a fixed wavelength band, one or a plurality of light detection elements or at least one-dimensional linear light detection A light detection unit configured by an element or a two-dimensional image sensor, and the measured intensity is obtained by performing Fourier transform or inverse Fourier transform on the intensity of each wavelength of the spectral or scanned interference light measured by the light detection unit. A depth vs. reflection characteristic data representing a reflection intensity corresponding to each depth position where the measurement light is reflected by the body is generated, and based on the depth vs. reflection characteristic data in each part of the measurement object. A method based on so-called Fourier domain method of obtaining 2-3-dimensional reflection characteristic data of the measured object,
The light source generates a point light beam, a linear light beam, or a surface light beam of a certain wavelength band at the same time, and the light detection unit has one or a plurality of light detection elements, at least a one-dimensional linear light detection element, or a two-dimensional image sensor. The reflection intensity corresponding to each depth position where the measurement light is reflected by the measurement object by the interference light measured by the light detection unit based on the interference light measured by the light detection unit. A method based on a so-called time domain method of generating 1 to 3 dimensional reflection characteristic data of the measured object based on the depth vs. reflection characteristic data in each part of the measured object,
The three-dimensional characteristic measurement / display device according to any one of claims 1 to 8, which is an optical coherence tomography device according to any one of the methods.