JP2981697B2 - Method and apparatus for measuring three-dimensional information of a specimen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring three-dimensional information of a specimen, and more particularly to a method of scanning a specimen spirally by electromagnetic waves, and non-destructively tomographic images and three-dimensional images of the specimen. And a method and apparatus for measuring the three-dimensional information.

[0002]

2. Description of the Related Art As a method for non-destructively measuring three-dimensional information of a specimen, that is, not only the outer surface of the specimen but also a tomographic image or a three-dimensional image of the specimen, for example, an X-ray CT method is known.

In this X-ray CT method, a sample is irradiated with one X-ray flux, and the X-ray flux is applied to a circumference in a plane centered on a virtual axis (hereinafter referred to as a body axis) of the sample and perpendicular to the body axis. 360 up
Rotate to form a tomographic image from the intensity of transmitted X-rays transmitted through the specimen, move the X-ray flux in the body axis direction, and rotate again as described above to obtain a tomographic image from the transmitted X-ray intensity. Is repeated, and three-dimensional information of the specimen is measured by interpolating and calculating image data in the body axis direction from the data of the plurality of transmitted X-ray images.

Therefore, the image data of the sample in the body axis direction has a problem in reliability with respect to the actual image data of the sample.

As a method for solving the above-mentioned difficulties, a helical scan X-ray CT method has been announced ("Principle and specification of helical scan" INNERVISION (7.6) 1992).

In the helical scan X-ray CT method, the X-ray flux in the above-mentioned conventional X-ray CT method is obtained by converting a rotational displacement about the body axis and a linear displacement in the body axis direction into a vector spiral. The transmission X obtained by this helical scan X-ray CT method
The line intensity data has continuity in the body axis direction, so that three-dimensional information of the specimen can be measured with high accuracy.

In recent years, in the above-mentioned method, a method of irradiating near-infrared light or laser light instead of X-rays and measuring biochemical or physiological information in a living body is known.

[0008]

However, it is desired that the three-dimensional information of a specimen is further improved in accuracy, particularly in the fields of biology and medicine. Has become indispensable.

In order to meet the above-mentioned demands in the three-dimensional information measuring method of the specimen, when the irradiating means for irradiating the above-mentioned X-ray or laser beam is scanned in a spiral manner, the spiral means may rotate in the direction of the rotation center axis of the spiral. It is necessary to reduce the scanning speed to improve the resolution of the image of the specimen along the axial direction. In this case, reducing the scanning speed increases the time required for scanning, resulting in a problem that measurement efficiency is reduced.

It is an object of the present invention to provide a method and an apparatus for measuring three-dimensional information of a specimen, which have been made in view of the above circumstances, and which can reduce the scanning time.

[0011]

Means for Solving the Problems Claim 1 according to the present invention.
The method for measuring three-dimensional information of a specimen described above includes irradiating the specimen with an electromagnetic wave, displacing the electromagnetic wave and the specimen relatively so that the electromagnetic wave scans the specimen in a spiral shape, and transmits the specimen. A method for measuring three-dimensional information of the sample by detecting the intensity of the electromagnetic wave obtained,
The electromagnetic waves emitted from the single electromagnetic wave emitting means are made incident on a plurality of electromagnetic wave irradiating means which are arranged at equal intervals around the sample and at least 360 degrees around the sample in a spiral manner. Irradiating the sample with the electromagnetic wave from the electromagnetic wave irradiation unit, and detecting the intensity of the plurality of electromagnetic waves transmitted through the sample by a plurality of electromagnetic wave detection units arranged at positions for detecting each of the electromagnetic waves. .

[0012]

According to a second aspect of the present invention , there is provided an apparatus for measuring the three-dimensional information of a specimen according to the first aspect of the present invention . The electromagnetic wave and the sample are relatively displaced so that the electromagnetic wave scans the sample in a spiral manner, and the intensity of the electromagnetic wave transmitted through the sample is detected to detect the intensity of the electromagnetic wave.
In a sample three-dimensional information measuring device for measuring dimensional information, a single electromagnetic wave emitting means and a spiral wound around the sample at equal intervals around at least 360 degrees around the sample, A plurality of electromagnetic wave irradiation means for receiving the electromagnetic waves emitted from the electromagnetic wave emission means and irradiating the specimen with electromagnetic waves; and an electromagnetic wave emitted from the electromagnetic wave emission means.
The traveling direction of the wave is sequentially changed in the direction of the plurality of electromagnetic wave irradiation means.
It is characterized by comprising a direction switching means for switching, and a plurality of electromagnetic wave detecting means for detecting the intensity of the plurality of electromagnetic waves transmitted through the sample for each of the electromagnetic waves.

[0014]

Here, the above-mentioned electromagnetic wave means not only an electromagnetic wave in a narrow sense but also an electromagnetic wave in a broad sense including infrared rays, visible rays, ultraviolet rays, X-rays, γ-rays and the like.

The helix is defined as a rotational displacement about an arbitrary virtual axis (hereinafter referred to as a body axis) of the specimen,
It means the trajectory of the displacement obtained by the vector sum with the linear displacement in the body axis direction.

[0017] Therefore, that the electromagnetic wave scans the sample in a helix spiral means that the electromagnetic wave is displaced along the helix and the electromagnetic wave irradiates the sample with the electromagnetic wave.

[0018] The above-mentioned arrangement of the spiral helix means that:
This means that a plurality of specimens are arranged at predetermined intervals on the helical spiral with the body axis of the specimen as the center axis of rotation.

Further, the equal spacing means that the above-mentioned predetermined intervals are equal.

[0020]

In the method for measuring three-dimensional information of a specimen according to the present invention, a plurality of electromagnetic wave irradiating means and a plurality of electromagnetic wave detecting means are arranged in a spiral shape around the specimen. Helical scanning.

That is, the light is emitted from a single electromagnetic wave emitting means.
The electromagnetic waves are suspended around the sample by the direction switching means.
Sequentially in the direction of a plurality of electromagnetic wave irradiation means arranged in a spiral
The traveling direction can be switched, thereby sequentially irradiating the specimen with electromagnetic waves from a plurality of electromagnetic wave irradiation means, and detecting the intensity of the electromagnetic waves transmitted through the specimen by the detection means, respectively, the specimen becomes a spiral spiral. Electromagnetic waves are irradiated, and intensity data of the electromagnetic waves is detected for each of the plurality of irradiated electromagnetic waves.

By the above operation, the intensity data of the electromagnetic wave obtained by transmitting the sample has continuity in the body axis direction of the sample, and moves the electromagnetic wave irradiation means, the electromagnetic wave detection means , and the sample. Since there is no need, the scanning time can be reduced as compared with the conventional method and apparatus. In addition,
The electromagnetic wave that irradiates this sample from multiple directions is a single electromagnetic wave
Since the light is emitted from the emission means, its output is always
Can be kept constant. Therefore, multiple
The electromagnetic wave is emitted separately from the magnetic wave emitting means.
Variations in the output of pan electromagnetic waves can be prevented.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 (a), 1 (b) and 1 (c) are conceptual views showing an embodiment of the apparatus for measuring three-dimensional information of a specimen according to the present invention. FIG. 1A shows seven laser beam irradiation means S ₁ , S ₂ ,..., S on a spiral helix L ₂ having a virtual axis L ₁ of the specimen 1 as a center axis of rotation. FIG. 1 (b) shows a state where ₇ are arranged at substantially equal intervals, and FIG. 1 (b) shows a top view of FIG. 1 (a). FIG.
(c) is a partially enlarged view of FIG. 1 (a). The illustrated two-dimensional parallel operation type image sensor d ₁ is a unit that laser light emitted from the laser light irradiation unit S ₁ transmits through the specimen 2 and two-dimensionally detects the intensity of the transmitted laser light. FIG.
In (a), the illustration is omitted for simplification of the drawing, but one is provided for each of the above seven laser beam irradiation means S ₁ , S ₂ ,..., S ₇ .

Next, the configuration of this embodiment will be described in detail with reference to the block diagram shown in FIG.

The three-dimensional information measuring apparatus for a specimen shown in FIG. 1 includes a laser light source 2 as an electromagnetic wave emitting means,
An intensity correction plate 3 for keeping the intensity distribution of the laser light emitted from the laser beam constant, a half-wave plate 4 for splitting the laser light into two laser light beams whose polarization planes are orthogonal to each other, and a polarization beam splitter 5. It has a frequency shifter 6 for converting the frequency of light to another slightly different frequency, and a polarization beam splitter 7 for wavefront matching, and these constitute a laser light emitting section 100.

Further, seven laser beam irradiation means as a plurality of electromagnetic wave irradiating means on said helical spiral around the sample S _1, S _2, ..., have S ₇ is arranged, the laser beam irradiation means S _1, S _2, ..., respectively S _7, a lens 8 for forming a laser beam to the conical beam, a polarization beam splitter 9 that divides the laser beam into two laser beams and wavefront matching, polarization of the laser beam A quarter-wave plate 10 for rotating the surface by 45 °, a first concave mirror 11 for reflecting one of the laser beams split by the polarizing beam splitter 9, and a concave mirror whose center of curvature coincides with the concave mirror; A second concave mirror 12 for reflecting the laser beam again to be incident on the polarizing beam splitter, and a polarizing plate 13 are provided.

However, in FIG. 2, for simplification of the drawing, the description of the internal structure of the laser beam irradiation means S ₂ , S ₃ ,..., S ₇ is omitted, but the laser beam irradiation means S ₁ , S ₂ ,
..., S ₇ are all the same size and the same configuration.

Furthermore, as the laser beam detecting means for detecting the intensity of the laser beam transmitted through the specimen in two dimensions, the laser beam irradiation means S _1, S _2, ..., 7 two-dimensional corresponding to each S ₇ The parallel operation type image sensors d ₁ , d ₂ ,
..., d ₇ are arranged.

Further, the image sensors d ₁ and d _1
2, ..., helical seven transmitted light projection image that is the separated detected with separate detecting transmitted light projected image of the specimen from the two-dimensional intensity image of seven laser light detected by the optical heterodyne detection method by d ₇ Measurement processing means 200 for measuring three-dimensional information of the sample by a scanning CT technique
Reconstructing means 300 for outputting a three-dimensional image of the sample or a tomographic image in a direction along an arbitrary cross section from the three-dimensional information, and seven laser light irradiating means for emitting laser light emitted from the laser light emitting section 100 A rotatable mirror 400 is provided as direction switching means for sequentially guiding light to S ₁ , S ₂ ,..., S ₇ . Laser beam irradiation means S ₁ of the three-dimensional information measurement device of the sample that is configured as described above, S _2, ..., S ₇ and the two-dimensional parallel operation type image sensor d _1, d _2, ..., a d _7, a specimen a perspective view seen through from the direction of the body axis L ₁ shown in FIG. 3 (a) of.

FIGS. 3 (b), 3 (c) and 3 (d) are sectional views taken along line II, II-II and III-III of FIG. 3 (a), respectively.
It is sectional drawing which shows a line cross section.

Next, the operation of this embodiment will be described.

The laser light emitted from the laser light source 2 is split into two optical paths by a polarizing beam splitter 5, and the laser light traveling on one optical path is converted into another frequency slightly different from the original frequency by a frequency shifter 6. (The frequency-converted laser light is hereinafter referred to as local laser light), and the local laser light and laser light traveling along the other optical path (hereinafter referred to as signal laser light) are converted by the polarization beam splitter 5. The laser beam is emitted from the laser beam emitting unit 100 after wavefront matching.

The laser beam emitted from the laser beam emitting portion 100 is incident is switched to the optical path by the optical path switching mirror 400 in the laser beam irradiation means S _1.

The laser beam incident on the laser beam irradiating means S ₁ is converted into a conical beam by a lens 8, and split into a signal laser beam and a local laser beam by a polarizing beam splitter 9. This signal laser light irradiates the surface of the specimen 1 and again makes the signal laser light transmitted through the specimen 1 by the polarizing beam splitter 9 and the local laser light wavefront-matched, and the two-dimensional intensity of the wavefront-matched laser light An image sensor for two-dimensional parallel operation (hereinafter abbreviated as image sensor) d ₁
Is detected by

[0036] then allowed to incident laser beam emitted by rotating the optical path switching mirror 400 from the laser light emitting unit 100 to the laser beam irradiation unit S _2. Laser light at this time is to project a two-dimensional intensity image on the image sensor d ₂ by the same action as when incident on the laser beam irradiation means S _1.

Further, the optical path switching mirror 400 rotates and the laser beam emitted from the laser beam emitting unit 100 is made incident on the laser beam irradiating means S ₃ , and the two-dimensional intensity is applied to the image sensor d ₃ by the same operation as described above. Project the image.

As described above, the mirror 400 is rotated so that the laser light is sequentially incident on the laser light irradiation means S ₁ , S ₂ ,..., S ₇ , and the corresponding two-dimensional intensity images are detected.

As described above, each of the image sensors d ₁ , d ₂ ,
.., D ₇ are subjected to measurement processing by the optical heterodyne detection method by the measurement processing means 200 to be converted into a transmitted light projection image of laser light transmitted through the specimen 1, and further to CT for helical scan. The three-dimensional information of the specimen is measured by the technique, and the reconstruction means 300 outputs a three-dimensional image of the specimen 1 or a tomographic image in a direction along an arbitrary cross section.

As described above, the method for measuring three-dimensional information of a specimen according to the present invention can be performed continuously in the body axis direction of the specimen only by slightly rotating the optical path switching mirror without moving the laser beam irradiation unit, the image sensor, and the specimen. It is possible to detect the transmitted light projected image of the specimen having the property, and to reduce the scanning time for scanning the specimen and the laser light irradiation unit.

[0041]

The electromagnetic wave applied to the specimen does not necessarily need to be laser light, but may employ near-infrared light, X-rays, or the like. For example, when X-rays are employed, an X-ray source can be directly arranged at the position of the electromagnetic wave irradiation means. That is, a plurality of X-ray sources may be arranged in a spiral shape around the sample 1 and the transmission X-ray detection means may be provided on an extension line connecting each X-ray source and the sample.

[Brief description of the drawings]

1A is a conceptual diagram showing an embodiment of a three-dimensional information measuring apparatus for a specimen of the present invention, FIG. 1B is a top view showing a top view of FIG.
(c) is a partially enlarged view of (a)

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 (a) is a perspective view of the sample of the three-dimensional information measuring apparatus according to the embodiment of the present invention as viewed from the body axis direction, and FIG.
(C) is a sectional view taken along the line II-II of (a), and (d) is a sectional view of (a).
III-III sectional view

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Sample 2 Laser light source 3 Intensity correction plate 4 1/2 wavelength plate 5,7,9 Polarization beam splitter 6 Frequency shifter 8 Lens 10 1/4 wavelength plate 11,12 Concave mirror 13 Polarization plate 100 Laser beam emission part 200 Measurement processing Means 300 Reconstruction means 400 Optical path switching mirror S _{1 to} S ₇ Laser light irradiation means d _{1 to} d ₇ Two-dimensional parallel operation type image sensor L ₁ Virtual axis (body axis) of sample L ₂ Spiral spiral

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 21/00-21/01 G01N 21/17-21/61 A61B 10/00 G01B 11/24 A61B 10/00 A61B 6 / 03

Claims (2)

(57) [Claims] An object is irradiated with an electromagnetic wave, and the electromagnetic wave and the sample are relatively displaced so that the electromagnetic wave scans the sample in a spiral manner, and the intensity of the electromagnetic wave transmitted through the sample is detected. In the method for measuring three-dimensional information of a sample, the electromagnetic waves emitted from a single electromagnetic wave emitting unit are arranged at equal intervals around the sample, at least at 360 degrees around the sample. A plurality of electromagnetic waves irradiating a plurality of electromagnetic waves irradiating means which are arranged in a spiral shape over the spiral, irradiate the specimen with the electromagnetic waves from the electromagnetic wave irradiating means, and the intensity of the plurality of electromagnetic waves transmitted through the specimen for each of the electromagnetic waves. A method for measuring three-dimensional information of a specimen, wherein the three-dimensional information is detected by a plurality of electromagnetic wave detecting means arranged at positions to be detected. Irradiating the sample with an electromagnetic wave, displacing the electromagnetic wave and the sample relatively so that the electromagnetic wave scans the sample in a spiral manner, and detects the intensity of the electromagnetic wave transmitted through the sample. A three-dimensional information measuring apparatus for measuring the three-dimensional information of the sample, wherein a single electromagnetic wave emitting means and a spiral helix are provided around the sample at equal intervals over at least 360 degrees around the sample. A plurality of electromagnetic wave irradiating means for receiving the electromagnetic wave emitted from the electromagnetic wave emitting means and irradiating the specimen with the electromagnetic wave, and the electromagnetic wave emitted from the electromagnetic wave emitting means.
The traveling direction is sequentially cut in the direction of the plurality of electromagnetic wave irradiation means.
A three-dimensional information measuring apparatus for a specimen , comprising: a direction switching means for changing the direction; and a plurality of electromagnetic wave detecting means for detecting the intensity of the plurality of electromagnetic waves transmitted through the specimen for each of the electromagnetic waves.