WO2022062049A1

WO2022062049A1 - Beam splitter-based imaging device integrating anterior segment oct and biometer functions

Info

Publication number: WO2022062049A1
Application number: PCT/CN2020/124350
Authority: WO
Inventors: 陈思思; 沈梅晓; 朱德喜; 邵一磊; 吕帆
Original assignee: 温州医科大学
Priority date: 2020-09-28
Filing date: 2020-10-28
Publication date: 2022-03-31
Also published as: CN112244760A

Abstract

A beam splitter (42)-based imaging device integrating the anterior segment OCT and biometer functions. Light of a reference arm (4) is split into two beams by means of the beam splitter (42); when being located at a first position, a movable shielding plate (45) can block a first beam of light of the reference arm (4), such that only a second flat mirror (44) can reflect and interfere with a sample arm (5), so as to achieve imaging of only the anterior segment; and when the movable shielding plate (45) is located at a second position, both a first flat mirror (43) and the second flat mirror (44) can reflect and interfere with the sample arm (5) and achieve imaging in the same image at the same time, so as to achieve the objective of keeping the positions of the cornea and retina relatively fixed during involuntary eye movement, thereby reducing the interference of factors such as eye movement on values, thus increasing accuracy of axial length measurement, especially in patients with poor gaze, such as special populations with nystagmus, Alzheimer's disease, etc.

Description

An Imaging Device Based on Spectroscopic Prism to Realize Anterior Segment OCT with Integrated Biometric Function

technical field

The invention relates to the technical field of medical devices, in particular to an imaging device based on a spectroscopic prism to realize the function of an anterior segment OCT integrated biometric instrument.

Background technique

Optical coherence tomography (OCT) is a new imaging technology based on the principle of low coherence optical interference. It has the characteristics of high resolution, fast scanning imaging, non-contact and non-destructive detection, and is widely used in the field of medical imaging. . Spectral domain OCT uses the spectrometer detection system to obtain the interference spectral signal, and obtains the depth information through the Fourier transform method, thereby further improving the imaging speed and imaging sensitivity. Spectral domain OCT is an important ophthalmic optical imaging technique.

At present, ophthalmic imaging OCT is divided into anterior segment OCT and fundus OCT according to the different imaging objects. The imaging range of anterior segment OCT includes the cornea, anterior chamber, iris and lens. Due to technical limitations, OCT can perform high-resolution imaging in mm thickness, but cannot achieve a large Z-axis scanning range. OCT imaging of the whole eye, that is, the simultaneous precise measurement of the anterior segment and the measurement of biometric functions such as the eye axis is of great value in the clinical and research fields of ophthalmology.

At present, eye biometry has entered the era of optical biometry with a resolution of about 0.1mm from the era of ultrasonic measurement with a resolution of about 0.1mm. Various types of optical biometry instruments have been widely used in clinical practice. The main measurement techniques used include partial optical coherence, such as Carl Zeiss IOLMaster 500 and Nidek AL-Scan; optical low coherence reflections such as Haag-Streit Lenstar LS900 and Suoer SW-9000; Optical low coherence interferometry, such as Topcon Aladdin, Tomey CASIA SS-1000, Tomey CASIA2. The above measurements are highly dependent on the patient's gaze coordination. Some patients with retinal detachment, silicone oil-filled aphakic eyes, vitreous hemorrhage nystagmus, and Alzheimer's disease, due to their disordered intraocular structure and poor eye gaze, are more severe than normal. The intraocular structure is more complex and changeable. During routine eye axis measurement, the interface such as the retina and hemorrhagic organizing membrane measured by the paired detachment is easy to be misinterpreted or caused by eye movements.

In order to overcome the deficiencies of the background technology, the present invention provides an imaging device based on a beam splitting prism to realize the function of an anterior segment OCT integrated biometric instrument.

technical solutions

The technical solution adopted in the present invention is: an imaging device based on a spectroscopic prism to realize the function of an anterior segment OCT integrated biometer, including a control center, a light source, a fiber coupler, a reference arm, a sample arm, and a spectrometer; the reference arm includes a first a collimating mirror, a beam splitting prism, a first plane reflecting mirror, a second plane reflecting mirror, and a movable shielding plate; the reference arm light is split into a first reference arm light beam and a second reference arm light beam after being split by the beam splitting prism. The first plane reflection mirror is arranged on the optical path of the first beam of reference arm rays, the first beam of reference arm rays can be perpendicular to the first plane reflection mirror, and the second plane reflection mirror is arranged on the light of the second beam of reference arm rays. On the way, the second beam of reference arm light can be perpendicular to the second plane mirror; the movable shielding plate is movably arranged between the beam splitting prism and the first plane mirror, which has the function of blocking the first beam of reference arm light so that it cannot reach. The first position of the first plane mirror, and the second position where the first beam of reference arm light is not blocked so that it can reach the first plane mirror for reflection.

The distance from the reference arm ray to the second plane mirror is the same as the distance from the sample arm ray to the anterior segment of the human eye, and the distance from the reference arm ray to the first plane mirror is the same as the distance from the sample arm ray to the posterior segment of the human eye.

The movable shielding plate is rotatably arranged.

The reference arm further includes an electric translation stage, and the first plane mirror is fixedly mounted on the electric translation stage, and can perform a linear reciprocating motion along the direction of the first beam of light of the reference arm.

The electric translation stage is provided with a grating ruler.

The sample arm includes a second collimator mirror, a first galvanometer, a first lens, a second lens, a second galvanometer, and a third lens, and the light of the sample arm can pass through the second collimator, the first galvanometer, and the third lens in sequence. The first lens, the second lens, the second galvanometer, and the third lens are then injected into the human eye.

The sample arm also includes a human eye tracking optotype system, which includes an optotype, a fourth lens, a tracking camera, a semi-transparent mirror, and a thermal mirror; the optotype passes through the fourth lens, The semi-transparent mirror and the hot mirror correspond to the human eye, the tracking camera corresponds to the human eye through the semi-transparent mirror and the thermal mirror, and the third lens corresponds to the human eye through the thermal mirror.

beneficial effect

The beneficial effects of the present invention are: adopting the above scheme, the beam splitting prism divides the reference arm light into two beams, and when the movable shielding plate is in the first position, the first beam of the reference arm light can be blocked, so that only the second plane mirror It can perform reflection and interference with the sample arm to achieve separate imaging of the anterior segment; when the movable shield is in the second position, both the first plane mirror and the second plane mirror can reflect and interfere with the sample arm, and simultaneously image In the same image, the position of the cornea and retina is still relatively fixed during the involuntary movement of the eyeball, thereby reducing the interference of factors such as eye movement on the value, and improving the accuracy of the measurement of the eye axis, especially when the gaze is relatively high. Poor patients such as nystagmus, Alzheimer's disease and other special groups.

Description of drawings

FIG. 1 is a schematic structural diagram of an imaging device for realizing an anterior segment OCT integrated biometric function based on a beam splitting prism according to an embodiment of the present invention.

2 is a schematic structural diagram of a reference arm when the movable shielding plate is in the first position according to an embodiment of the present invention.

3 is a schematic structural diagram of a reference arm when the movable shielding plate is in the second position according to an embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a sample arm according to an embodiment of the present invention.

FIG. 5 is a schematic structural diagram of a spectrometer according to Embodiment 1 of the present invention.

FIG. 6 is an OCT imaging diagram of the first embodiment of the present invention when the movable shielding plate is in the second position (the left picture is an optical model eye, and the right picture is a real human eye).

FIG. 7 is a schematic structural diagram of a reference arm according to Embodiment 2 of the present invention.

FIG. 8 is a schematic structural diagram of a reference arm according to Embodiment 3 of the present invention.

Embodiments of the present invention

Embodiments of the present invention will be further described below in conjunction with the accompanying drawings:

Example 1

As shown in Figures 1-5, an imaging device based on a spectroscopic prism to realize the function of an anterior segment OCT integrated biometric instrument includes a control center 1, a light source 2, a fiber coupler 3, a reference arm 4, a sample arm 5 and a spectrometer 6.

The control center 1 can use a computer, which is mainly used for action control and image analysis and processing.

The light source 2 is used to output a light beam, which can be an SLD light source with a center wavelength of 840-880 nm and a bandwidth of 45 nm.

The fiber coupler 3 can be a 2X2 fiber coupler, which is set corresponding to the light source 2. The fiber coupler 3 can divide the light beam output by the light source 2 into two, one for the reference arm light entering the reference arm 4, and one for the reference arm. The sample arm light enters the sample arm 5, and the reflected reference arm light can interfere with the sample arm light at the same time.

The reference arm 4 includes a first collimating mirror 41, a beam splitting prism 42, a first plane reflecting mirror 43, a second plane reflecting mirror 44, and a movable shielding plate 45. The light of the reference arm passes through the first collimating mirror 41 and then exits horizontally. Entering the beam splitting prism 42, the beam splitting prism 42 can adopt a semi-transparent mirror, which divides the reference arm light into a first reference arm light beam and a second reference arm light beam, and the first reference arm light beam completely passes through the beam splitting prism 42, The two reference arm rays are reflected at an angle of 45°. The first reference arm rays and the second reference arm rays are vertically distributed at an angle of 90°. The first plane reflector 43 is arranged behind the beam splitting prism 42. After passing through the beam splitting prism 42, a beam of reference arm light can be perpendicular to the first plane mirror 43 and reflected. The second plane mirror 44 is arranged on the side of the beam splitter prism 42, and the second beam of reference arm light is split by the beam. After the prism 42 is refracted, it can be vertically incident on the second plane reflecting mirror 44 and reflect. The movable shielding plate 45 is movably arranged between the beam splitting prism 42 and the first plane reflecting mirror 43, and has the function of blocking the first beam of reference arm light. It cannot reach the first position of the first plane mirror 43 and does not block the first beam of reference arm light so that it can reach the second position of the first plane mirror 43 . Among them, the movable shielding plate 45 can be rotated by a micro electric hinge, and is connected with the control center 1, and the control center 1 performs control actions.

Of course, the dichroic prism 42 is not limited to transflective, and different proportions can be selected according to actual needs.

The sample arm 5 includes a second collimating mirror 51, a first galvanometer mirror 52, a first lens 53, a second lens 54, a second galvanometer mirror 55, and a third lens 56. The light of the sample arm passes through the second collimating mirror 51. It is emitted in parallel, passes through the first galvanometer 52, the first lens 53, the second lens 54, the second galvanometer 55, and the third lens 56 in turn, and then enters the human eye; wherein, the first galvanometer 52 and the second galvanometer 55 It can make the light of the sample arm turn, and the first lens 53 and the second lens 54 have the same focal length, so as to realize the 4F imaging of the scanning galvanometer and reduce optical distortion, and the third lens 56 is used for focal length adjustment, so that the focal length of the sample arm light can be adjusted. land on the desired site for imaging.

In addition, the sample arm 5 further includes a human eye tracking optotype system 7 , and the human eye tracking optotype system 7 includes an optotype 71 , a fourth lens 72 , a tracking camera 73 , a half mirror 74 , and a thermal mirror 75 The optotype 71 corresponds to the human eye through the fourth lens 72, the semi-transparent mirror 74 and the hot mirror 75, and the tracking camera 73 corresponds to the human eye through the semi-transparent mirror 74 and the hot mirror 75. The third lens 56 corresponds to the human eye through the thermal mirror 75 , and the human eye tracking the optotype system 7 can further increase the convenience of use of the instrument and the degree of cooperation of the patient.

The spectrometer 6 includes a third collimating mirror 61, a grating 62, a lens 63, and a camera 64. The spectrometer 6 is arranged corresponding to the fiber coupler 3, and the reflected reference arm light and the sample arm light interfere with the fiber coupler 3. After entering the spectrometer 6, it passes through the third collimating mirror 61, the grating 62 and the lens 63 to focus, and is collected by the camera 64. The camera 64 is connected to the control center 1, and can transmit the collected signals to the control center 1. The control center 1 performs subsequent image analysis and processing.

The distance from the reference arm ray to the second plane mirror 44 is the same as the distance from the sample arm ray to the anterior segment of the human eye, and the distance from the reference arm ray to the first plane mirror 43 is the same as the distance from the sample arm ray to the posterior segment of the human eye.

When the movable shielding plate 45 is in the first position, the first beam of reference arm light is blocked by the movable shielding plate 45 and cannot enter the first plane reflector 43 for reflection, and only the second beam of reference arm light enters the second plane reflector 44 It reflects and interferes with the reflected sample arm light. Since the optical path difference of the second plane mirror 44 is matched with the human anterior segment, it can image the anterior segment alone.

When the movable shielding plate 45 is in the second position, the first beam of reference arm light enters the first plane mirror 43 and is reflected, the second beam of reference arm light enters the second plane mirror 44 and is reflected, and the two reference arm beams are reflected. It can reflect and interfere with the light of the sample arm respectively. Since the second plane mirror 44 and the first plane mirror 43 are respectively matched with the optical path difference of the anterior segment and the posterior segment of the eye, the anterior segment and the posterior segment of the eye can be simultaneously imaged in the same image. middle.

The imaging process of the imaging device based on the spectroscopic prism to realize the anterior segment OCT integrated biometric function is as follows:

Preganglionic OCT Mode

The movable shielding plate 45 is in the first position, the light source 2 emits light, and the light is divided into two after passing through the fiber coupler 3, one of which is the sample arm light, and the sample arm light passes through the second collimating mirror 51 and the first galvanometer in turn. 52. The first lens 53, the second lens 54, the second galvanometer 55, and the third lens 56 enter the human eye and form reflected light back to the fiber coupler 3 according to the original path, and the other beam is the reference arm light. The light rays pass through the first collimating mirror 41 and exit in parallel, the reference arm rays pass through the beam splitting prism 42 and are divided into two parts, the first reference arm rays are blocked by the movable shielding plate 45, and the second reference arm rays enter the second plane mirror After 44, it is reflected, and the reflected light is returned to the fiber coupler 3 according to the original path. Here, the reflected light of the sample arm light interferes with the reference arm light, and then enters the spectrometer 6, and passes through the third collimating mirror 61 and the grating 62 in turn. After the light is split and the lens 63 is focused, the camera 64 collects the collected signals. The camera 64 transmits the collected signals to the control center 1, and the control center 1 performs subsequent image analysis and processing.

Biometric Imaging Mode

The movable shielding plate 45 is in the second position, the light source 2 emits light, and the light is divided into two after passing through the fiber coupler 3, one of which is the sample arm light, and the sample arm light passes through the second collimating mirror 51 and the first galvanometer in turn. 52. The first lens 53, the second lens 54, the second galvanometer 55, and the third lens 56 enter the human eye and form reflected light back to the fiber coupler 3 according to the original path, and the other beam is the reference arm light. The light rays exit in parallel after passing through the first collimating mirror 41, the reference arm rays pass through the beam splitting prism 42 and are divided into two, and the first beam of reference arm rays enter the first plane mirror 43 and are reflected to form the reflected light back to the original path. In the fiber coupler 3, the second beam of reference arm light enters the second plane mirror 44 and is reflected to form the reflected light back to the fiber coupler 3 according to the original path. Here, the reflected light of the sample arm light and the two beams of reference arm light Interfere separately, and then enter the spectrometer 6, pass through the third collimating mirror 61, grating 62 for light splitting, and lens 63 to focus, and then collect by the camera 64. The camera 64 transmits the collected signals to the control center 1, and the control center 1 Perform subsequent image analysis and processing.

As shown in Figure 6, the OCT image in the imaging mode of the biometer, the left image is an optical model eye, and the right image is a real human eye, which can clearly image the anterior surface of the cornea, the posterior surface of the cornea, the iris, and the retina. . Then, by calculating the distance between the cornea and the retina in the image, plus the conversion of the optical path difference and the refractive index in the reference arm, the eye axis value can be calculated.

With the above solution, by controlling the movement of the movable shielding plate 45, it can be in the first position or the second position, so that it has two imaging function modes, the pre-segmental OCT mode and the biometric imaging mode. When in the biometric imaging mode At the same time, the anterior segment and the posterior segment of the eye can be imaged in the same image at the same time, so that the cornea and retina are still relatively fixed during the involuntary movement of the eyeball, thereby reducing the interference of factors such as eye movement on the value, and improving the eye movement. The accuracy of axial measurement, especially in patients with poor gaze such as nystagmus, Alzheimer's disease and other special populations.

Embodiment 2

The second embodiment is basically the same as the first embodiment, the difference is that the reference arm 4 further includes an electric translation stage 46 that can perform a linear reciprocating motion along the direction of the first reference arm light beam.

As shown in FIG. 7 , the first plane mirror 43 is installed on the electric translation stage, and the electric translation stage 46 is connected to the control center 1. The electric translation stage 46 can be controlled to move by the control center 1, thereby driving the first plane reflection mirror. 43 Do straight reciprocating movements.

Through the design of the electric translation stage 46, the inherent mode of the fixed design of the original flat mirror is abandoned, thereby getting rid of the inherent measurement range limitation of the OCT system, and realizing the measurement of the eye axis in a wider depth range.

Embodiment 3

The third embodiment is basically the same as the first embodiment, the difference is that the reference arm 4 further includes an electric translation stage 46 capable of linear reciprocating motion along the direction of the first reference arm light beam. The electric translation stage 46 is provided with a grating ruler 47 .

As shown in FIG. 8 , the first plane mirror 43 is installed on the electric translation stage. The electric translation stage 46 and the grating ruler 47 are connected to the control center 1. The control center 1 can control the electric translation stage 46 to move, thereby driving the first A flat mirror 43 performs a linear reciprocating motion.

In addition to the measurement of the eye axis in a wider depth range, the grating scale and the electric translation stage 46 can realize closed-loop automatic control, and the absolute positioning accuracy can reach the micron level, realizing high-precision biological measurement.

In the description of the present invention, it should be noted that the terms "center", "portrait", "horizontal", "top", "bottom", "front", "rear", "left", "right", " The orientations or positional relationships indicated by vertical, horizontal, top, bottom, inside, and outside are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying It is described, not indicated or implied, that the imaging device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations. Also, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

Note to all technicians: Although the present invention has been described according to the above-mentioned specific embodiments, the inventive idea of the present invention is not limited to this invention, and any modification using the idea of the present invention will be included in the protection scope of this patent right.

Claims

An imaging device for realizing the function of an anterior segment OCT integrated biometer based on a spectroscopic prism, comprising a control center (1), a light source (2), an optical fiber coupler (3), a reference arm (4), a sample arm (5), and a spectrometer (6);

It is characterized in that: the reference arm (4) comprises a first collimating mirror (41), a beam splitting prism (42), a first plane reflecting mirror (43), a second plane reflecting mirror (44), and a movable shielding plate (45) ); the reference arm light is divided into a first reference arm light beam and a second reference arm light beam after being split by the beam splitting prism (42), and the first plane reflector (43) is arranged on the optical path of the first reference arm light beam , the first beam of reference arm light can enter the first plane reflection mirror (43), the second plane reflection mirror (44) is arranged on the optical path of the second beam of reference arm light, and the second beam of reference arm light can enter a second plane mirror (44);

The movable shielding plate (45) is movably arranged between the beam splitting prism (42) and the first plane reflection mirror (43), and has the function of blocking the first beam of reference arm light so that it cannot reach the first plane reflection mirror (43). a first position, and a second position where the first beam of reference arm light is not blocked so that it can reach the first plane mirror (43) for reflection.
The imaging device for realizing the function of an anterior segment OCT integrated biometric instrument based on a spectroscopic prism according to claim 1, characterized in that: the distance between the light from the reference arm reaching the second plane mirror (44) and the distance between the light from the sample arm reaching the anterior segment of the human being The distances are the same, and the distance that the light from the reference arm reaches the first plane mirror (43) is the same as the distance that the light from the sample arm reaches the back segment of the human eye.
The imaging device for realizing the function of an anterior segment OCT integrated biometric instrument based on a spectroscopic prism according to claim 1, characterized in that: the movable shielding plate (45) is set in rotation.
The imaging device for realizing the function of an anterior segment OCT integrated biometric instrument based on a beam splitting prism according to claim 1, characterized in that: the reference arm (4) further comprises an electric translation stage (46), and the first plane mirror (43) It is fixedly installed on the electric translation stage (45), and can perform a linear reciprocating motion along the direction of the first beam of reference arm light.
The imaging device for realizing the function of an anterior segment OCT integrated biometric instrument based on a spectroscopic prism according to claim 4, characterized in that: a grating ruler (46) is provided on the electric translation stage (45).
The imaging device for realizing the function of an anterior segment OCT integrated biometric instrument based on a beam splitter prism according to claim 1, characterized in that: the sample arm (5) comprises a second collimator (51), a first galvanometer (52) ), a first lens (53), a second lens (54), a second galvanometer (55), and a third lens (56), the sample arm light can pass through the second collimator (51), the first galvanometer in sequence (52), the first lens (53), the second lens (54), the second galvanometer (55), and the third lens (56) are then injected into the human eye.
The imaging device for realizing the function of an anterior segment OCT integrated biometric instrument based on a spectroscopic prism according to claim 6: the sample arm (5) further comprises a human eye tracking optotype system (7), the human eye tracking optotype system (7) comprising an optotype (71), a fourth lens (72), a tracking camera (73), a half mirror (74), and a thermal mirror (75); the optotype (71) passes through the fourth lens ( 72), the transflective mirror (74), and the hot mirror (75) correspond to the human eye, and the tracking camera (73) corresponds to the human eye through the transflective mirror (74) and the hot mirror (75), so The third lens (56) corresponds to the human eye through the thermal mirror (75).