KR101242315B1 - Dual focusing optical coherence imaging system - Google Patents

Abstract

The present invention, the light source for generating light of a wide band; A main light splitter for distributing and proceeding the light generated from the light source unit; First and second interferers, which form interference signals for different focal regions of the subject using light distributed from the optical splitter, respectively, and are commonly connected to the first and second interferers An interference unit having a common sample arm; An optical switch connected to the first and second interferers and configured to select the interference signal transmitted from the first and second interferers; And a detection unit for converting the interference signal selected according to a preset mode from the optical switch into an electrical signal.

Description

DUAL FOCUSING OPTICAL COHERENCE IMAGING SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coherence imaging apparatus, and more particularly, to an optical coherence imaging apparatus having a compact structure that enables acquisition of image information for a plurality of regions through a single scan operation.

 Optical coherence tomography (OCT) is one of the most advanced medical imaging technologies in recent years, and it has the representative advantage of non-invasive, high-speed, micro-scale tomographic imaging of internal tissue structures. Since OCT's OCT for retinal imaging has succeeded in commercialization, it has spurred various OCT-related merchandising researches such as endoscopic OCT, OCT for skin diagnosis and OCT for tumor diagnosis. In addition, technologies for speeding up image acquisition, techniques for obtaining high resolution images, techniques for reducing production costs, and techniques for minimizing noise effects are being actively conducted for clinical applications.

 1 is a basic schematic diagram of a spectral domain optical coherence tomography system according to the prior art. The light source 21 uses a low coherence broadband light source, and in the ophthalmic OCT, a light source having a wavelength of 800 nm band and 1300 nm band is used. The light generated from the light source 21 passes through the light splitter 24 and is mirrored. It is divided into the reference stage with (22) and the sample stage with the test object. When the light travel distance from the light splitter 24 to the mirror at the reference stage and the light travel distance from the light splitter 24 to the inspection target at the sample stage are the same, the light reflected from the mirror and the light reflected from the sample are light. The splitter meets again to generate an interference signal, and the generated interference signal is incident to the spectrometer 26 and finally detected by the line scanning camera through the diffraction grating and the lens.

 The conventional ophthalmic OCT system is composed of the basic system as described above and uses two lenses at the sample stage to inject parallel light into the eye, and to focus on the retina through the lens present in the eye. In many cases, the cornea and the retina are measured and then evaluated and diagnosed. However, there is no OCT technique that simultaneously measures the cornea and the retina.

That is, in the case of the OCT according to the prior art, the position of the reference mirror is fixed so that an image is acquired at the part of focusing by the sample lens, so that the cornea and the retina with one spectroscope are different from each other. Simultaneous measurement was technically impossible, which means that when the mirror position of the reference stage is set based on the focal length of the retina, there is a considerable distance difference between the optical distance to the retina and the optical distance to the cornea. This is because image information acquisition is physically impossible.

  In addition, when the cornea is in front of the lens in the eye and the retina is positioned behind the lens to send parallel light to image the retina, the cornea is not focused and the cornea cannot be imaged. Therefore, the current system is capable of measuring only one retina or cornea. To solve this problem, two spectrometers must be used, but the increase in the number of spectrometers increases the manufacturing cost of the device and makes it difficult to achieve a compact configuration. do.

Accordingly, an object of the present invention is to provide a dual focusing optical coherence imaging device having a compact structure that enables acquisition of image information of a plurality of focal regions for a single subject through a single scan.

The present invention for achieving the above object, the light source for generating a light band; A main light splitter for distributing and proceeding the light generated from the light source unit; First and second interferers, which form interference signals for different focal regions of the subject using light distributed from the optical splitter, respectively, and are commonly connected to the first and second interferers An interference unit having a common sample arm; An optical switch connected to the first and second interferers and configured to select the interference signal transmitted from the first and second interferers; And a detection unit for converting the interference signal selected according to a preset mode from the optical switch into an electrical signal.

In the dual focusing optical coherence imaging apparatus, the first interfering unit includes: a first optical splitter receiving wide band light distributed from the main optical splitter and a first sample receiving light split from the first optical splitter A first sample arm having an arm collimator, a first reference arm collimator receiving light distributed from the first optical splitter other than the light distributed to the first sample arm, and light from the first reference arm collimator It may be provided with a first reference arm comprising a first reference mirror that reflects and returns to the first optical splitter.

In the dual focusing optical coherence imaging apparatus, the second interfering unit includes: a second optical splitter receiving wide band light distributed from the main optical splitter and a second sample receiving light split from the second optical splitter A second sample arm having an arm collimator, a second reference arm collimator receiving light distributed from the second optical splitter other than the light distributed to the second sample arm, and light from the second reference arm collimator It may be provided with a second reference arm including a second reference mirror which reflects and returns to the second optical splitter.

In the dual focusing optical coherence imaging apparatus, the first interfering unit includes: a first optical splitter receiving wide band light distributed from the main optical splitter and a first sample receiving light split from the first optical splitter A first sample arm having an arm collimator, a first reference arm collimator receiving light distributed from the first optical splitter other than the light distributed to the first sample arm, and light from the first reference arm collimator A first reference arm including a first reference mirror to reflect and return to the first optical splitter, wherein the second interference unit comprises: a second optical splitter receiving wide band light distributed from the main optical splitter; A second sample arm having a second sample arm collimator receiving the light distributed from the second optical splitter, and the light distributed to the second sample arm A second reference arm including a second reference arm collimator receiving light distributed from the second optical splitter and a second reference mirror reflecting light from the second reference arm collimator and returning the light to the second optical splitter The common sample arm may include: a common arm splitter configured to reflect light transmitted through the first sample arm collimator and the second sample arm collimator, and the light reflected from the common arm splitter; A Coerman arm optical scanner that irradiates toward different focal regions of the light, and focuses the light irradiated from the common arm optical scanner to irradiate different focal regions of the subject, and again reflects light reflected from the different focal regions of the subject. A common arm objective lens may be provided to deliver the common arm optical scanner.

In the dual focusing optical coherence imaging apparatus, a first sample arm focus lens may be further provided between the first sample arm collimator and the common arm optical splitter.

In the dual focusing optical coherence imaging apparatus, a first reference polarization controller is provided between the first optical splitter and the first reference arm collimator, and a second reference is provided between the second optical splitter and the second reference arm collimator. Polarization regulators may be provided.

In the dual focusing optical coherence imaging apparatus, the optical switch is connected to the first optical splitter and the second optical splitter to receive respective interference signals and transmit them to the detection unit, wherein the optical switch and the first optical A switching polarization controller may be arranged at one or more positions between the splitter and the second splitter and the detection unit.

In the dual focusing optical coherence imaging device, a first sample arm focus lens is further provided between the first sample arm collimator and the common arm optical splitter, wherein the subject is an eyeball, and the first sample arm is an eye. One of the focal regions of light transmitted from the collimator may be the cornea.

In the dual focusing optical coherence imaging apparatus, the other one of the focal regions of the light transmitted from the second sample arm collimator may be a retina.

In the dual focusing optical coherence imaging apparatus, the detection unit comprises: a detection collimator for emitting an interference signal selected by the optical switch as parallel light, a detection diffraction grating for diffracting light incident from the detection collimator, and the detection diffraction; It may be provided with a detection lens for focusing the diffracted light in the grating, and a detector for converting the diffracted light incident from the detection lens into an electrical signal.

In the dual focusing optical coherence imaging apparatus, an optical isolator may be provided between the light source unit and the main spectrometer to allow only the light from the light source unit to be transferred to the main spectrometer.

In the dual focusing optical coherence imaging device, at least one of the main optical splitter and the optical splitter provided in the interference unit may include an optical fiber splitter.

In the dual focusing optical coherence imaging apparatus, a control unit for receiving an electrical signal from the detection unit, a storage unit connected to the control unit and storing preset data, an electrical signal transmitted from the detection unit and the storage unit is pre-set On the basis of the setting data, a calculation unit for calculating the image information by performing a calculation according to the control signal of the control unit, and a display unit for displaying the image information in accordance with the image control signal of the control unit.

In the dual focusing optical coherence imaging apparatus, the light source unit may include a wavelength variable light source.

In the dual focusing optical coherence imaging apparatus, a portion of the first interference portion and the second interference portion and the common sample arm may form a hand held probe.

The dual focusing optical coherence imaging device according to the present invention having the configuration as described above has the following effects.

First, the dual focusing optical coherence imaging device according to the present invention enables simultaneous or alternative image acquisition through a single scan of a single subject.

Second, the dual focusing optical coherence imaging apparatus according to the present invention may simultaneously or alternatively acquire an image through image scanning of the eye retina and cornea as a subject under a single scan.

Third, the dual focusing optical coherence imaging apparatus according to the present invention can simultaneously or alternatively acquire images of different focal regions so as to acquire an interference signal for a subject under a sequential or preset switching operation through an optical switch. By doing so, it is possible to compact the device and reduce manufacturing cost.

Fourthly, the dual focusing optical coherence imaging apparatus according to the present invention enables simultaneous or alternative image acquisition for different focal regions to acquire an interference signal for a subject under sequential or preset switching operation through an optical switch. In this case, the number of spectrometers may be unified, thereby minimizing the distortion of the image signal, the simple switching of the trigger signal, and the minimization of measurement time due to the need for a software / hardware-based image signal correction algorithm.

Fifth, the dual focusing optical coherence imaging device of the present invention is irradiated with the focused light on the cornea for cornea measurement through the technical modification of the system, and at the same time by irradiating parallel light on the eye for measuring the retina, Simultaneous measurement of the retina can be enabled, and two fiber couplers are used to fix the position of the reference mirror for corneal measurement and the position of the reference mirror for retinal measurement separately. By adjusting the optical distance of the light, individual diagnostic image information of the cornea and retina can be acquired simultaneously.

Sixth, the dual focusing optical coherence imaging device of the present invention may increase the convenience of diagnosis of the patient and reduce medical costs and time by simultaneous measurement of the retina and cornea.

Seventh, the dual focusing optical coherence imaging device of the present invention includes a variable wavelength light source and includes a corresponding detection unit, which simultaneously or alternatively to sequential image acquisition for the different focal regions through the optical switch, and at the same time overall compact By making the structure, it is possible to improve the space utilization or portability due to the reduction in manufacturing cost or compactness of the mounting space.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

1 is a schematic block diagram of an imaging apparatus according to the prior art.
2 is a schematic block diagram of a dual focusing optical coherence imaging apparatus according to an embodiment of the present invention.
3 is a schematic state diagram of an eye being a subject of a dual focusing optical coherence imaging apparatus according to an embodiment of the present invention.
4 to 6 are image information derived through the dual focusing optical coherence imaging apparatus according to an embodiment of the present invention.
7 is a schematic block diagram of additional components of a dual focusing optical coherence imaging device according to an embodiment of the present invention.
8 is a schematic block diagram of another type of dual focusing optical coherence imaging apparatus according to an embodiment of the present invention.
9 is a schematic partial perspective view of another type of dual focusing optical coherence imaging apparatus according to an embodiment of the present invention.

Hereinafter, a dual focusing optical coherence imaging device will be described with reference to the drawings.

1 shows a schematic block diagram of an imaging apparatus according to the prior art, FIG. 2 shows a schematic block diagram of a dual focusing optical coherence imaging apparatus according to an embodiment of the invention, and FIG. A schematic state diagram of an eye being a subject of a dual focusing optical coherence imaging apparatus according to an embodiment is shown, and FIGS. 4 to 6 show image information derived through the dual focusing optical coherence imaging apparatus according to an embodiment of the present invention. 7 is a schematic block diagram of additional components of a dual focusing optical coherence imaging apparatus according to an embodiment of the present invention, and FIG. 8 is a dual focusing light according to an embodiment of the present invention. A schematic block diagram of another type of coherence imaging device is shown, and FIG. 9 illustrates a dual focusing optical coherence imaging device according to an embodiment of the present invention. A schematic partial perspective view of another type is shown.

The dual focusing optical coherence imaging apparatus 10 according to the exemplary embodiment of the present invention includes a light source 100, an interference unit 200, an optical switch 300, and a detection unit 400.

The light source unit 100 generates light of a wide band, and the light source unit 100 includes a low coherence light source in this embodiment. Hereinafter, a case in which a light source unit of a low coherence light source and a detector are provided with a line scan camera and a detection unit as a spectroscopic unit for implementing a spectroscopic function will be described. In another embodiment, a wavelength variable light source, A structure including a photodiode or a dual balance photodetector as a light source unit using a high speed wavelength variable light source and a detector of a detection unit will be described.

The average time interval at which a light wave reaching a point in any space oscillates predictably and maintains a sinusoidal shape without phase change is called coherence time, which is a measure of lacking the time coherence of light waves. to be. Observing from a fixed point in space, the advancing light waves oscillate in the form of a sine function only during time intervals in which the phase remains constant. coherence length) and is used as a measure of the extent to which light waves are spectroscopically pure. The low coherence light source is a light source having a short interference distance of light waves, and has a wide spectral band. Transmission paths between components for transmitting light of a wide band generated from the light source 100 are implemented as optical fibers.

The light of the light band generated from the light source unit 100 is transmitted to the main optical splitter 120. In this embodiment, an optical isolator 110 is disposed between the main optical splitter 120 and the light source unit 100. . The optical isolator 110 is a device for blocking the light traveling in the opposite direction of the light travel direction, in the process of transferring the broadband light generated from the light source unit 100 to the main optical splitter 120, in contrast, the light source unit 100 The light source unit 100 may be protected by blocking transmission of reflected light to the side.

The main optical splitter 120 divides the light of the light band transmitted from the light source unit 100 and transmits the divided light to the first and second interference units 201a and 201b.

The ratio distributed from the main optical splitter 120 to the first interfering unit 201a and the second interfering unit 201b of the interfering unit 200 is used for obtaining images from the cornea and the retina as the focal region described below in this embodiment. Although set in an equivalent ratio, this is only an embodiment of the present invention and various modifications are possible depending on the intended use and setting environment.

The light distributed through the main optical splitter 120 is transmitted to each of the interference units 201a and 201b and the common sample arm 202 of the interference unit 200, irradiated to the subject, and then reflected and formed as an interference signal. Is transmitted to the detection unit 400 through the optical switch 300 to be described below. The interference unit 200 includes a first interference unit 201a, a second interference unit 201b, and a common sample arm 202 as described above, and includes a first interference unit 201a and a second interference unit 201b. Is the same as the common sample arm 202. That is, the first interfering unit 201a and the second interfering unit 201b have different reference arms which are described below for acquiring image information on different areas of the same subject, but have a common common sample arm. By forming a structure to form different focus areas from each other, it is possible to obtain individual image information through different focus areas for the same subject.

The first interference unit 201a includes a first optical splitter 210a, a first sample arm 220a, and a first reference arm 230a. The first optical splitter 210a receives the light of the wide band distributed from the main optical splitter 120 and redistributes it. The first optical splitter 210a is connected to the first sample arm 220a and the first reference arm 230a, and each of the redistributed light is separated from the first optical splitter 210a by the first sample arm 220a and the first sample arm 220a. 1 is transferred to the reference arm 230a.

The first sample arm 220a includes a first sample arm collimator 223a, which is connected to the first optical splitter 210a through the first sample arm optical fiber 221a. The first sample arm collimator 223a is formed of parallel light by the light transmitted from the first optical splitter 210a. The light formed by the parallel light is common sample arm 202 which is below from the first sample arm collimator 223a. It is irradiated to the focal region of the subject S through the sample.

Light distributed from the first optical splitter 210a is transmitted to the first reference arm 230a, which includes a first reference arm collimator 233a and a first reference mirror 235a. . The first reference arm collimator 233a is connected to the first optical splitter 210a through the first reference arm optical fiber 231a. Through such a structure of the first reference arm optical fiber 231a, it is possible to smoothly form a parallel state between the first reference arm collimator 233a and the first reference mirror 235a described below. The first reference polarization regulator 237a may be disposed between the first optical splitter 210a and the first reference arm collimator 233a in order to reduce the influence because the light intensity of the light due to 231a may be affected. Can be. The first reference polarization controller 237a may form the shape of light closer to Gaussian while maximizing the light intensity of the broadband light from the light source unit.

Like the first sample arm collimator 223a, the first reference arm collimator 233a also makes the light of the wide band form parallel light. Parallel light emitted from the first reference arm collimator 233a is irradiated to the first reference mirror 235a. The irradiated light is reflected by the first reference mirror 235a and returned to the first optical splitter 210a through the first reference arm collimator 233a, which is reflected by the first reference mirror 235a to reflect the first optical splitter ( The light returned to 210a passes through the common sample arm 202 to be passed through the first sample arm 220a, and then is reflected from the subject S and returned to the first optical splitter 210a. The interference with the light of the focal region is formed to form an interference phenomenon to form an interference signal for obtaining an image of the first focal region of the subject.

The second interference unit 201b also has the same structure as the first interference unit 201a, and includes a second optical splitter 210b and a second optical beam that receive the wide band light distributed from the main optical splitter 120. The second sample arm 220b having the second sample arm collimator 223b receiving the light distributed from the distributor 210b, and the second optical splitter 210b other than the light distributed to the second sample arm 220b. A second reference arm collimator 233b receiving light distributed from the second reference arm, and a second reference mirror 235b reflecting the light from the second reference arm collimator 233b to return to the second optical splitter 210b. And a second reference arm 230b, and the second sample arm 220b and the second reference arm 230b are connected to the second sample arm optical fiber 221b and the second reference arm optical fiber 231b, respectively. Is the same as the structure for the first interference unit 201a, but the first interference unit 201a and the second interference The 201b forms a structure for acquiring image signals for different focal regions P1 and P2 for the same subject S, respectively. The distances l1 and l2 between each of the first reference arm collimator 233a and the first reference mirror 235a and the second reference arm collimator 233b and the second reference mirror 235b are different from each other. ≠ l2). In addition, as in the first interference unit 201a, the second interference unit 201b also includes a second reference polarization controller 237a between the second optical splitter 210b and the second reference arm collimator 233b. You can also place it.

The main optical splitter, the first optical splitter, and the second optical splitter described above are implemented as fiber couplers to achieve stable and constant light distribution and output regardless of the incident angle of the light, and to achieve a compact and compact configuration. It may be.

The common sample arm 202 includes a common arm optical splitter 203, a common arm optical scanner 204, and a common arm objective lens 205. The common arm optical splitter 203 transmits the light transmitted through the first sample arm collimator 223a and the second sample arm collimator 223b to the common arm optical scanner 204. The common arm optical scanner 204 may be implemented in a galvanometer type, which is a mirror-mounted structure that rotates at a predetermined angle and speed. The light passing through the common arm optical scanner 204 is irradiated to the subject S through the common arm objective lens 205 and, more specifically, to the focal regions P1 and P2 of the subject S. The common arm objective lens 205 includes two common arm first objective lenses 205-1 and a common arm second objective lens 205-2 in the present embodiment. The present invention is not limited thereto, and various configurations are possible depending on the relationship between the design specification and the focus area of the subject to be measured.

Therefore, the light of the wide band respectively distributed through the first interferometer 201a and the second interferometer 201b of the interference unit 200 through the main optical splitter 120 is again provided to each first optical splitter 210a. It is delivered to each of the first sample arm 220a / second sample arm 220b and the first reference arm 230a / second reference arm 230b via the second optical splitter 210b. Light passing through the first sample arm 220a / the second sample arm 220b is transmitted to the common common sample arm 202 and irradiated to the respective focal regions P1 and P2 of the subject P. Thereafter, the reflected light which makes it possible to acquire the image signals for the respective focal regions P1 and P2 is the common sample arm 202 and the first sample arm 220a / second sample arm as opposed to the incident time. Returned to each of the first optical splitter 210a / the second optical splitter 210b via the 220b, at the same time is distributed in the first optical splitter 210a / second optical splitter 210b, respectively. Light transmitted to the reference arm 230a / the second reference arm 230b is reflected by the first reference mirror 235a / the second reference mirror 235b and passes through the reverse path, respectively, to the first optical splitter 210a / first. 2 is returned to the optical splitter 210b. Therefore, the reflected light for the image acquisition of the focal region (P1, P2) of the subject S through the first sample arm 220a / second sample arm 220b and the common sample arm 202, An interference signal is generated as an interference phenomenon with light reflected from the first reference mirror 235a / the second reference mirror 235b via the first reference arm 230a / the second reference arm 230b.

Meanwhile, in the present exemplary embodiment, a first sample arm focus lens 207 is further provided between the first sample arm collimator 223a and the common arm optical splitter 203, through the first sample arm focus lens 207. It is possible to achieve accurate transmission of light to the first focal region P1 through the first interference unit 201a. Through such a configuration, light incident through the first sample arm 220a of the first interference unit 201a forms a predetermined optical path and passes through the common sample arm 202 to allow the first object S to be examined. The light incident to the focal region P1 is accurately focused and incident through the second sample arm 220b of the second interference part 201b to form a different light path than the light from the first sample arm 220a. Through the common sample arm 202, it is possible to accurately focus incident to the second focus region P2 instead of the first focus region P1. In this embodiment, the first sample arm focus lens 207 is provided, but the second sample arm focus lens may have a structure disposed between the second sample arm and the stop sample arm. Various modifications are possible depending on the detection conditions. The subject S according to the present embodiment is an eyeball, and the focal regions P1 and P2 are indicated as corneas and retinas, respectively. The first focal region to which light transmitted from the first sample arm collimator 223a of the unit 201a is irradiated is set to the cornea. FIG. 3 shows a schematic state diagram of the eyeball S as a subject. When the focal region is formed in the region indicated by the reference A, image information of the cornea and / or the lens can be acquired, and the reference B is shown. When the focal region is formed in the area indicated by, the image information of the retina and / or the choroid may be acquired.

In FIG. 2, the line segments indicated by reference numerals Lr and Lc represent optical paths of light transmitted and reflected through the respective interference units, and the optical path indicated by reference numerals Rr represents a path of light through the first interference unit 201a. And an optical path indicated by a reference numeral Lc indicates a path of light through the second interference unit 201b. As shown, light incident on the eye being the subject S through the first interference part 201a is focused at the cornea, which is the first focal region P1, and is reflected by the cornea, which is the first focal region P1. The light takes an inverse path and meets the reflected light from the first reference arm 230a at the first optical splitter 210a to form an interference signal to form an interference signal for image acquisition. In addition, light incident on the eye being the subject S through the second interfering part 201b is parallel light and is focused and reflected in the retina, which is the second focal region P2, by a crystalline lens in the eye. As a result, image information on the retina can be obtained. In this embodiment, the first focus region is set to the cornea and the second focus region is set to the retina, but the use environment is adjusted by adjusting the first reference arm / second reference arm and / or the common arm objective lens and / or the sample arm focus lens. And it may be configured in a variety of positions depending on the specifications, such as use.

The interference signal formed by the first optical splitter 210a / the second optical splitter 210b is transmitted to the optical switch 300, and the optical switch 300 includes the first optical splitter 210a and the second optical splitter 210b. Connected with. The optical switch 300 performs a switching operation to sequentially emit light as an interference signal, that is, the interfering light for the first focal region P1 through the first interference unit 201a, that is, the interference signal and the second interference unit ( Interfered light for the second focal region P2 through 201b, that is, an interference signal, is transmitted to the detection unit 400 described below.

In the present embodiment, the optical switch 300 uses a high speed optical switch for an 800 nm optical region, and the optical switch 300 performs a selective operation through a control signal so that the first and second focus regions, namely, Various selections are possible, such as simultaneous imaging of the same cornea and retina, single imaging of the cornea as the first focus region, and single imaging of the retina as the second focus region.

Meanwhile, at least one switching polarization controller 310 (310a, 310b, 310c) may be disposed before and after the optical switch 300. That is, in the present exemplary embodiment, the switching polarization controllers 310 (310a, 310b, 310c) are disposed between the optical switch 300 and the first optical splitter 210a and between the optical switch 300 and the second optical splitter 210b. And, and takes the structure disposed between the optical switch 300 and the detection unit 400, the switching polarization regulator (310; 310a, 310b, 310c) is stable to minimize the loss of the intensity of the transmitted interference signal It is possible to achieve the transmission of the interference signal.

The detection unit 400 converts the interference signal transmitted from the optical switch 300 into an electrical signal. In the present embodiment, the detection unit 400 is implemented as a spectral unit, but as described below, the light source unit is implemented as a wavelength variable light source. In this case, the detection unit may take a variety of configurations in the range of converting an interference signal into an electrical signal, such as a structure having a detector such as a compact photodiode or a dual balanced photo detector. have. The detection unit 400 implemented as a spectroscopic unit includes a detection collimator 410, a detection diffraction grating 420, a detection lens 430, and a detector 440. The detection collimator 410 converts the interference signal selected and transmitted from the optical switch 300 into parallel light and outputs it to the detection diffraction grating 420.

The detection diffraction grating 420 diffracts the interference signal as incident parallel light. In the present embodiment, the detection diffraction grating 420 used a transmission grating of 1200grooves / mm, which is specified in the specification. Various choices are possible.

Light diffracted at the detection diffraction grating 420 is transmitted to the detector 440 through the detection lens 430. In the present embodiment, the detector 440 is implemented as a line scan camera having a scanning rate of 70000 lines / s. However, when the light source unit is implemented as a wavelength variable light source, the detector of the detection unit is a photodiode or a dual balance photo having a compact structure. Various selections can be made according to specifications, such as a dual balanced photo detector, and various modifications can be made according to specifications within a range that includes a detection function for converting an optical interference signal into an electrical signal.

The electrical signal converted from the interference signal through the detection unit 400 is transmitted to the control unit 20, which is converted into a digital signal. The dual focusing optical coherence imaging apparatus 10 of the present invention includes a control unit 20, a storage unit 30, an operation unit 40, and a display unit 50 as shown in FIGS. 2 and 7. The controller 20 is electrically connected to the storage 30 and the calculator 40. The storage unit 30 may preset store preset data including preset image conversion data necessary for converting an electrical signal from the detection unit 400 into an image signal. The calculation unit 40 performs an inverse fast Fourier transform (IFFT) and / or k-domain correction on the vertical horizontal component of a predetermined calculation process, that is, the digitally converted signal received from the detection unit according to the operation control signal of the control unit 20. (k-domain calibration), and the control unit 20 causes the display unit 50 to output an image control signal using preset image conversion data stored in the storage unit 30 according to the calculation result. May be applied to achieve image display of real-time image information.

Meanwhile, the preset data of the storage unit 30 may include preset mode data for a mode for switching the optical switch. That is, the dual focusing optical coherence imaging apparatus 10 of the present invention may further include an input unit 60, and an input signal including a user's intention through the input unit 60 may be input by the user. The preset mode through the preset mode data preset in the unit 30 may be displayed on the display unit 50, and when the selection is made through the input unit 60 by the user, the selection input signal is sent to the controller 20. The controller 20 may transmit and control the optical switch 300 to acquire image information about a desired focus area of the subject and display the image on the display unit 50.

In addition, although the dual focusing optical coherence imaging apparatus of the present invention has been described as an integrated apparatus in the foregoing embodiment, the dual focusing optical coherence imaging apparatus of the present invention is not limited thereto, and various modifications are possible. That is, as shown in FIG. 8, another type of dual focusing optical coherence imaging device 10a of the present invention may further include a hand held probe 80. That is, the hand held probe 80 may be configured to include a part of the first interference part 201a and the second interference part 201b and the common sample arm 202. The first interference part 201a The first sample arm collimator 223a, the second sample arm collimator 223b of the second interference part 201b, and the common sample arm 202 are stably embedded in the probe body 81 (see FIG. 9). Taking the structure, each component may take the structure of being connected to the first optical splitter and the second optical splitter via an optical fiber. Through such a configuration, it is possible to take a structure that can be observed smoothly even when the subject is not seated.

In addition, the hand-held probe unit 80 may further include a probe display 90 to enhance user convenience (see FIG. 9).

FIG. 4 and FIG. 5 show image information obtained for the portion indicated by reference numerals A and B of FIG. 3 through the dual focusing optical coherence imaging apparatus. 4 shows image information acquired simultaneously for the retina and cornea in a single scan by sequentially switching the optical switches. FIGS. 5 and 6 show image information for a specific focal region by maintaining the optical switch in a constant mode, respectively. That is, the case where the image information about the cornea and the image information about the retina is acquired is shown. As described above, the present invention can execute various selective diagnostic functions that achieve simultaneous acquisition or alternative acquisition of image information for different focal regions through a single scan of a single subject.

In addition, although the light source unit uses a low coherence light source in the above embodiment, the present invention is not limited thereto, and the light source unit may include a variable wavelength light source. As shown in FIG. 10, the light source unit 100b of the wavelength variable light source included in the dual focusing optical coherence imaging apparatus 10b according to another embodiment of the present invention is an optical amplifier using a gain mechanism in a semiconductor active layer such as a semiconductor laser. The semiconductor light amplifier may be implemented as a semiconductor optical amplifier (SOA) for converting electrical energy supplied from a power supply (not shown) into light. The light source unit 100b implemented as a semiconductor optical amplifier has a wide bandwidth in the 800 nm band. In the case of using the wavelength variable light source, the detection unit may be implemented with a simple structure. That is, as shown in FIG. 10, the detection unit 400b may have a simple structure including a detector 440b for directly receiving the light of the interference signal output from the switching polarization controller 310c and converting the light into an electrical signal. . The detector 440b may be implemented as a photodiode or a dual balanced photo detector.

Through such a structure, it is possible to achieve a compact and compact configuration by eliminating a complex spectroscopic unit structure, which may be combined with the above-described handheld type to improve the realization of a mobile imaging device.

The above embodiments are examples for describing the present invention, but the present invention is not limited thereto. The hand-held fruit part can take a structure that can be reliably de-tacked to the main body 11 (see FIG. 8) to enable selective operation, such as to form a double focus area for a subject and to perform a single scan for a single subject. Various operations are possible in a range in which an image acquisition for two focus areas is achieved through an operation, but the optical switch is switched to take an image acquisition for a desired focus area.

10 ... Dual focusing optical coherence imaging device 20 ... Control unit
30 storage 40 operation
50 Display unit 100 Light source unit
200 ... interference unit 300 ... optical switch
400 ... detection unit

Claims (15)

A light source unit generating light of a wide band;
A main light splitter for distributing and proceeding the light generated from the light source unit;
First and second interferers, which form interference signals for different focal regions of the subject using light distributed from the optical splitter, respectively, and are commonly connected to the first and second interferers An interference unit having a common sample arm;
An optical switch connected to the first and second interferers and configured to select the interference signal transmitted from the first and second interferers;
And a detection unit for converting the interference signal selected according to a preset mode from the optical switch into an electrical signal. The method of claim 1,
The first interference portion:
A first optical splitter receiving the wide band light distributed from the main optical splitter;
A first sample arm having a first sample arm collimator receiving light distributed from the first optical splitter;
A first reference arm collimator receiving light distributed from the first optical splitter other than the light distributed to the first sample arm, and a second reflecting light from the first reference arm collimator to return to the first optical splitter A dual focusing optical coherence imaging device comprising a first reference arm comprising a first reference mirror. The method of claim 1,
The second interference portion is:
A second optical splitter receiving the wide band light distributed from the main optical splitter;
A second sample arm having a second sample arm collimator receiving light distributed from the second optical splitter;
A second reference arm collimator receiving light distributed from the second optical splitter other than the light distributed to the second sample arm, and a second reflecting light from the second reference arm collimator to return to the second optical splitter 2. A dual focusing optical coherence imaging device comprising a second reference arm comprising a second reference mirror. The method of claim 1,
The first interference portion:
A first sample arm including a first optical splitter receiving wide band light distributed from the main optical splitter, a first sample arm collimator receiving light split from the first optical splitter, and the first sample arm A first reference arm collimator receiving light distributed from the first optical splitter other than the light distributed to the first splitter, and a first reference mirror reflecting light from the first reference arm collimator to return to the first optical splitter And having a first reference arm
The second interference portion is:
A second sample arm including a second optical splitter receiving wide band light distributed from the main optical splitter, a second sample arm collimator receiving light split from the second optical splitter, and the second sample arm A second reference arm collimator receiving light distributed from the second optical splitter other than the light distributed to the second splitter, and a second reference mirror reflecting light from the second reference arm collimator to return to the second optical splitter And having a second reference arm
The common sample arm is:
A common arm optical splitter for reflecting light transmitted through the first sample arm collimator and the second sample arm collimator;
A common arm optical scanner for irradiating light reflected from the common arm optical splitter toward different focal regions of the subject;
And a common arm objective lens for focusing the light irradiated from the common arm optical scanner to irradiate different focal regions of the subject, and to transmit light reflected from the different focal regions of the subject back to the common arm optical scanner. Dual focusing optical coherence imaging device, characterized in that. 5. The method of claim 4,
And a first sample arm focusing lens between the first sample arm collimator and the common arm optical splitter. 5. The method of claim 4,
A first reference polarization controller is provided between the first optical splitter and the first reference arm collimator,
And a second reference polarization controller between the second optical splitter and the second reference arm collimator. 5. The method of claim 4,
The optical switch is connected to the first optical splitter and the second optical splitter and receives respective interference signals and transmits them to the detection unit, wherein the optical switch and the first optical splitter and the second optical splitter and the detection A dual focusing optical coherence imaging device, characterized in that a switching polarization adjuster is arranged at one or more positions between the units. 5. The method of claim 4,
A first sample arm focus lens is further provided between the first sample arm collimator and the common arm optical splitter.
The subject is an eyeball, wherein one of the focal regions of the light transmitted from the first sample arm collimator is the cornea. The method of claim 8,
And the other one of the focal regions of light transmitted from the second sample arm collimator is a retina. The method of claim 1,
The detection unit is:
A detection collimator for emitting the interference signal selected by the optical switch as parallel light;
A detection diffraction grating for diffracting light incident from the detection collimator,
A detection lens for focal transfer of light diffracted by the detection diffraction grating;
And a detector for converting the diffracted light incident from the detection lens into an electrical signal. The method of claim 1,
And a light isolator between the light source unit and the main spectroscope to allow only light from the light source unit to be transferred to the main spectrometer. The method of claim 1,
And at least one of the main optical splitter and the optical splitter provided in the interference unit comprises an optical fiber splitter. The method of claim 1,
A control unit for receiving an electrical signal from the detection unit;
A storage unit connected to the control unit and storing preset data;
An arithmetic unit configured to calculate image information by executing arithmetic operations according to a control signal of the controller based on the electrical signal transmitted from the detection unit and preset data of the storage unit;
And a display unit for displaying the image information according to the image control signal of the controller. The method of claim 1,
And the light source unit includes a variable wavelength light source. The method of claim 1,
And a portion of the first interferer and the second interferer and the common sample arm form a hand held probe.

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