KR101480947B1 - Imaging device of retina using grin lens - Google Patents

Abstract

An embodiment of the present invention relates to an apparatus for photographing a retina by using a GRIN lens. An objective is to photograph a retina image in a high resolution by reducing an aberration by using a GRIN lens including an optical fiber having a slanted end part. To this end, an embodiment of the present invention discloses an apparatus for photographing a retina by using a GRIN lens, which photographs the retina image by inducing a first light irradiating from a first light source to an eye to be examined through GRIN lens and guiding a third light with respect to the first light reflected from the eye to be examined to a camera through the GRIN lens. A plurality of optical fibers are provided at the outer circumference of the GRIN lens, in which the optical fibers extend longer that the GRIN lens in one direction, and an end part of the optical fiber is slantingly formed to face the eye to be examined.

Description

TECHNICAL FIELD [0001] The present invention relates to a retina imaging apparatus using a GRIN lens,

An embodiment of the present invention relates to a retina imaging device using a GRIN lens capable of reducing aberration using a GRIN lens to capture a high resolution retina image.

Image technology is a very important field in the field of biomedicine. In particular, in the field of disease research, techniques for imaging animals using animals can determine the biomarker of the disease. In addition, in the field of ophthalmology research, it is possible to diagnose various diseases related to optic nerve disorder using the retinal image of the animal and to analyze the process and to use it for early diagnosis.

In particular, it is essential to see the retina of a laboratory animal, especially a mouse, before human clinical application. However, shooting a very small eye like a mouse is very difficult.

Compared to the human eye (24mm), the small 3mm mouse and the 6mm mouse have a 300D aberration, which is much larger than the human aberration of 65D. A special camera lens design is essential to capture images of such aberrations and small eyes. In general, a retinal camera used for human ophthalmologic diagnosis has various functions and has different diagnostic methods according to the eye diseases. For example, a retinal imaging camera requires a function called Fluoresence Angiography (FA), Autofluorescence Agiography (AF), and ICG. And it is not easy to measure images of various methods with a single retinal camera. For example, in a fundus camera, the illumination method usually uses a mask to minimize the reflection of the central portion of the lens. Small eyes like mice have several side effects when using these masks, and the design varies depending on the type of animal.

On the other hand, optical instruments using a GRIN lens (gradient index lens) have been developed very much. Unlike conventional lenses, these GRIN lenses are designed to be used in the same way as ordinary lenses by using a rod gradient refractive index of a cylinder model. The most important example is endoscopy. Using such a GRIN lens, a very compact endoscope is used to photograph the internal structure of a person and to treat it. Accordingly, photographing and analyzing various types of retinal image modalities with one device using a GRIN lens is beneficial for research and medical applications.

Korean Patent Registration No. 10-1348939 " Fundus camera " Japanese Laid-Open Patent Publication No. 10-2004-0038520 'angular distribution type lens'

An embodiment of the present invention provides a retina imaging device using a GRIN lens capable of capturing an image of a retina with a high resolution by reducing aberration using a GRIN lens provided with an optical fiber formed so that an end is inclined.

A retina imaging apparatus using a GRIN lens according to an embodiment of the present invention includes a GRIN lens for guiding a first light emitted from a first light source to a subject's eye and a third light for a first light reflected from the subject, A plurality of optical fibers are provided on an outer circumference of the GRIN lens, and the optical fiber is extended to one side relatively longer than the GRIN lens, and the optical fiber And the end portion may be formed so as to be inclined to face the eye to be examined.

The end of the optical fiber may be inclined so that light passing through the optical fiber is directed toward the subject.

A dichroic beam splitter that transmits or reflects third light passing through the GRIN lens; First and second lenses for improving the optical performance of the transmitted third light; And a camera for picking up an image of the eye to be examined using the third light having improved optical performance.

A wheel filter may be provided between the first and second lenses and the camera to provide a third light having improved optical performance by the first and second lenses to the camera.

The camera may include at least three CCD chips to capture one color image for the third light.

Wherein the first light source comprises a plurality of light emitting diodes (LEDs) and emits light having wavelengths of different colors; And an optical fiber cable for transmitting light of different colors to the optical fiber bundle, wherein a focusing lens unit for focusing light of different colors is provided between the light emitting unit and the optical fiber cable, and the optical fiber cable, A relay optical unit for adjusting the amount of energy of light of different colors may be provided.

A light beam emitted from a super-luminous element (Super Luminescent Diode) and reflected through a MEMS scanner is focused on an eye to be examined through a GRIN lens, and light reflected from the subject is transmitted through the GRIN lens to one side of the dichroic beam splitter And OCT equipment for receiving the tomogram of the eye to be examined.

The retina imaging device using the GRIN lens according to an embodiment of the present invention reduces the aberration by guiding the light emitted from the optical fiber to the eye to be examined using the GRIN lens having the optical fiber formed so that the end is inclined, It is possible to capture a high resolution retina image at the same time.

1 is a schematic view of a retina imaging device using a GRIN lens according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an optical fiber covering portion provided in the GRIN lens of FIG. 1; FIG.
3 is a view showing an optical fiber illumination pattern using the end structure of the optical fiber of FIG.
FIG. 4 is a view schematically showing the first light source of FIG. 1; FIG.
FIG. 5 is a schematic view of the OCT apparatus of FIG. 1. FIG.

The terms used in this specification will be briefly described and the present invention will be described in detail.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Also, in certain cases, there may be a term selected arbitrarily by the applicant, in which case the meaning thereof will be described in detail in the description of the corresponding invention. Therefore, the term used in the present invention should be defined based on the meaning of the term, not on the name of a simple term, but on the entire contents of the present invention.

When an element is referred to as "including" an element throughout the specification, it is to be understood that the element may include other elements, without departing from the spirit or scope of the present invention. Also, the terms "part "," channel ", and the like described in the specification mean units for processing at least one function or operation, which may be implemented by hardware or software or by a combination of hardware and software .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

2 is a cross-sectional view illustrating an optical fiber covering unit provided in the GRIN lens of FIG. 1, and FIG. 3 is a cross-sectional view of the optical fiber of FIG. 2, FIG. 4 is a schematic view of the first light source of FIG. 1, and FIG. 5 is a view schematically showing the OCT equipment of FIG.

1 to 3, a retina imaging apparatus using a GRIN lens according to an embodiment of the present invention includes a first light source 40, a first GRIN lens 10, a dichroic beam splitter 50, 1 and the second lens 60, 70, and a camera 90. [

The retina imaging apparatus using the GRIN lens guides the first light emitted from the first light source 40 to the eye to be examined 1 through the first GRIN lens 10 and focuses the first light reflected from the eye 1 And the third light for the light is led to the camera 90 through the first GRIN lens 10 to pick up an image of the retina.

In the present specification, the eye to be examined 1 refers to a mouse eye including a mouse or a rat, but may mean an eye of an animal such as a mouse, not limited to this.

The first light source 40 is a device that emits light having wavelengths of different colors to the first GRIN lens 10 by using a plurality of LEDs. More specifically, the first light source 40 directs the divergent light to the end of the optical fiber provided on the outer circumference of the first GRIN lens 10 through the optical fiber bundle 30.

4, the first light source 40 includes a light diverging unit 46, relay optical units 41 and 42, an optical fiber cable 43, and a focusing lens unit 44 , 45).

The light diverging unit 46 is composed of a plurality of LEDs, and emits light having wavelengths of different colors.

The focusing lens units 44 and 45 are provided between the light diverging unit 46 and the optical fiber cable 43 to focus the lights of different colors to the optical fiber cable 43 in the same direction.

The optical fiber cable 43 transmits light of different colors controlled by the relay optics 41 and 42 to the fiber optics bundle 30 via the relay optics 41 and 42.

The relay optics 41 and 42 are provided between the optical fiber cable 43 and the optical fiber bundle 30 to adjust energy amounts of light of different colors.

More specifically, the first light source 40 is connected to the optical fiber bundle 30 through the first GRIN lens 10 through the relay optics 41 and 42, And is finally connected to the light diverging unit 46. [ In this case, the focusing lens units 44 and 45 composed of the two lenses in front of the light divergence unit 46 are arranged in such a manner that the light energy of the LEDs constituting the light divergence unit 46 is minimized, The amount of LED energy can be adjusted by moving the LED back and forth. The LED can be changed to emitting a certain wavelength, and can be changed to a white, yellow, blue, or red LED according to the user's demand.

Referring to FIG. 2, an optical fiber covering portion 20 is provided on the outer circumference of the first GRIN lens 10, and a plurality of optical fibers 21 are provided in the optical fiber covering portion 20. The optical fiber 21 is extended to one side relatively longer than the first GRIN lens 10. Referring to FIG. 3, the end of the optical fiber 21 may be provided with an inclined region 21a formed to be inclined to face the eye to be examined 1. The inclined region 21a is a region where the end portion of the optical fiber 21 is cut so as to guide the light passing through the optical fiber 21 toward the eye to be examined 1. [ At this time, the angle formed by the inclined region 21a with one longitudinal surface of the optical fiber 21 (for example, an inclined angle with respect to the surface of the lower optical fiber 21 in Fig. 3) is in the range of 30 degrees to 45 degrees Lt; / RTI > When the angle formed between the inclined region 21a and one surface of the optical fiber 21 in the longitudinal direction is 30 degrees or less, the reflected light is difficult to collect in the subject's eye 1. If the angle is 45 or more, ), The effect may be insignificant.

Accordingly, in the present invention, in order to increase the energy efficiency, the end portion of the optical fiber 21 may be inclined so as to form a certain angle, unlike the other optical fibers, so that almost all the light sources are allowed to enter the eye to be examined 1, . As such, the light illuminated on the retina will not be reflected on any lens, which can be very helpful in taking images. Further, the light reflected from the retina is again formed through the first GRIN lens 10 in front of the dichroic beam splitter 50 with the first image.

The dichroic beam splitter 50 transmits or reflects third light passing through the first GRIN lens 10. Also, light reflected from the retina is formed in front of the dichroic beam splitter 50 through a first GRIN lens 10 with a first image.

The first and second lenses 60 and 70 improve the optical performance of the third light transmitted by the dichroic beam splitter 50. That is, the first and second lenses 60 and 70 focus the image formed in front of the dichroic beam splitter 50 in the same direction toward the camera 90 and provide the image to the camera 90, To form a retinal image again. In particular, the second lens is effective for focusing an image by moving left and right.

A third light having an improved optical performance is selected by the first and second lenses 60 and 70 between the first and second lenses 60 and 70 and the camera 90, A wheel filter 80 may be provided. The wheel filter 80 is a device that allows images to be taken using various light characteristics. Such a wheel filter 80 is designed to be adapted not only to FA, AF, and ICG, which are generally used in ophthalmology, but also to the convenience of the user.

The camera 90 is an apparatus for picking up an image of the eye to be examined 1 by using third light having improved optical performance and includes at least three CCD chips to pick up one color image for the third light .

That is, the camera 90 is a color camera 90, which is different from an ordinary color camera (Bayer type), and forms one color image by using three CCD chips, so that there is almost no halo of the image.

The retina imaging device according to an embodiment of the present invention configured as described above can significantly reduce aberrations by canceling the curved surface of a very large cornea of a mouse using a GRIN lens without special lens design, Resolution image can be taken. In addition, the retina imaging apparatus can guide the light emitted from the optical fiber 21 to the eye by giving an angle to the end portion of the optical fiber 21 in order to increase energy efficiency without using a mask. In addition, the retina imaging apparatus has an advantage that various different wavelengths can be used according to the diagnostic function of the eye using LEDs.

5, the retina imaging device using the present GRIN lens is configured to detect an image of the subject's eye 1 through an OCT (Optical Coherence Tomography) apparatus 100 formed on one side of a dichroic beam splitter 50 Area or tomography can be performed.

Hereinafter, the OCT apparatus 100 formed on one side of the dichroic beam splitter 50 as described above will be described in detail with reference to FIG.

First, the second light source 107 of the OCT apparatus 100 uses an SLD light source. For example, the second light source 107 may be a super luminescent diode. The light emitted from the second light source 107 is reflected through the MEMS scanner 102 and the reflected light is transmitted to the first GRIN lens 10 through the second GRIN lens 109. At this time, the center wavelength of the light emitted from the second light source 107 is 850 nm and a bandwidth of about 150 nm is formed. In addition, the light has a coherence length of about 2.1 microns in air.

The second light source 107 separates the diverged light through the beam splitter 105 through the single mode sample channel optical fiber 104 and 90% of the light passes through the sample channel optical fiber 104 ). The remaining light enters a reference channel 106 to balance the sample channel. At this time, the light reflected from the reference channel 106 and the sample channel optical fiber 104 causes an interference phenomenon, and the light having the interference is measured by a detection channel 108.

Also, the light emitted from the sample channel optical fiber 104 is collimated through the collimator lens 103. Since the collimator lens 103 moves forward and backward, it is possible to adjust focusing on another layer in the retina.

The collimated light can be photographed not only as a B scan showing one cross-sectional area but also as a volume image through a MEMS scanner (Scanner) 102, and can perform a scan scan as well as a line scan have. In addition, it can be made very small in size by taking advantage of the unique advantages of MEMS.

The light modulated and reflected by the MEMS scanner 102 is again focused on the focusing lens 101 and moved through the second GRIN lens 109. This light is reflected by the dichroic beam splitter 50 to form an image in front of the dichroic beam splitter 50. The light then enters the first GRIN lens 10 and arrives at the retina of the eye do. At this time, the light reflected from the retina of the eye comes to the sample channel optical fiber 104 through the same optical path.

The retina imaging device according to another embodiment of the present invention configured as above can combine OCT image technology with a retinal imaging device to perform tomographic imaging at desired locations.

The present invention is not limited to the above-described embodiment, but may be applied to other embodiments of the present invention, such as the present invention 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 spirit and scope of the present invention.

1: eye to be examined 10: first GRIN lens
20: optical fiber jacket 21: optical fiber
21a: inclined region 30: fiber bundle
40: first light source 41, 42: relay optical part
43: optical fiber cable 44, 45: focusing lens part
46: light emitting portion 50: dichroic beam splitter
60, 70: first and second lens 80: wheel filter
90: Camera 100: OCT equipment
101: focusing lens 102: MEMS scanner
103: collimator lens 104: sample channel optical fiber
105: beam splitter 106: reference channel
107: second light source 108: detection channel
109: Second GRIN lens

Claims (7)

A retina imaging device for guiding a first light emitted from a first light source to a subject through a GRIN lens and guiding a third light for the first light reflected by the subject to the camera through the GRIN lens ,
A plurality of optical fibers are provided on an outer circumference of the GRIN lens,
Wherein the optical fiber is extended to one side relatively longer than the GRIN lens and the end of the optical fiber is inclined to face the eye to be examined.
The method according to claim 1,
Wherein an end of the optical fiber is formed to be inclined so that light passing through the optical fiber is directed toward the subject to be examined.
The method according to claim 1,
A dichroic beam splitter that transmits or reflects third light passing through the GRIN lens;
First and second lenses for improving the optical performance of the transmitted third light; And
Further comprising a camera for capturing an image of the eye to be examined using the third light having improved optical performance.
The method of claim 3,
Wherein a wheel filter is provided between the first and second lenses and the camera to provide a third light having improved optical performance by the first and second lenses to the camera. Retinal imaging device.
The method according to claim 1,
Wherein the camera comprises at least three CCD chips to capture one color image for the third light.
The method according to claim 1,
The first light source
A light diverging unit comprising a plurality of LEDs (diodes) for emitting light having wavelengths of different colors; And
And an optical fiber cable for transmitting lights of different colors to the optical fiber bundle,
A focusing lens unit for focusing light beams of different colors is provided between the light diverging unit and the optical fiber cable,
Wherein a relay optical unit is provided between the optical fiber cable and the optical fiber bundle for controlling the amount of energy of light of different colors.
The method of claim 3,
At one side of the dichroic beam splitter,
An OCT apparatus for focusing the light reflected by the MEMS scanner through a GRIN lens and projecting the light reflected from the subject through the GRIN lens to obtain a tomographic image of the eye to be examined, Wherein the GRIN lens comprises a plurality of lenses.

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