CN117547218A

CN117547218A - Optical system and method for measuring eye axis length

Info

Publication number: CN117547218A
Application number: CN202311547355.8A
Authority: CN
Inventors: 蔡守东; 吴蕾; 李鹏
Original assignee: Shenzhen Moting Medical Technology Co ltd
Current assignee: Shenzhen Moting Medical Technology Co ltd
Priority date: 2023-11-20
Filing date: 2023-11-20
Publication date: 2024-02-13

Abstract

The invention discloses an optical system for measuring the axial length of an eye and a method thereof, wherein the optical system comprises an OCT light source module, an OCT imaging module, an OCT sample arm module of a posterior segment and an OCT fracture imaging assembly of an anterior segment, the OCT light source module provides measuring light, the measuring light passes through the OCT sample arm module of the posterior segment and then enters the fundus of the eye to be measured, and the OCT imaging module receives the measuring light to acquire an OCT image of the posterior segment; the anterior ocular segment crack imaging assembly comprises an anterior ocular segment crack light source module, an anterior ocular segment crack imaging module and an anterior ocular segment crack imaging adjustment light path module, wherein the anterior ocular segment crack light source module provides crack light, the crack light passes through the anterior ocular segment crack imaging adjustment light path module and then focuses on the anterior ocular segment of a person to be tested, and the anterior ocular segment crack imaging module receives the crack light to acquire an anterior ocular segment crack image; and respectively acquiring first optical path data and second optical path data by utilizing the OCT image of the posterior segment and the fracture image of the anterior segment so as to calculate and obtain the axial length of the eye. The invention avoids the influence of eye movement of the person to be measured and improves the measurement precision of the eye axis length.

Description

Optical system and method for measuring eye axis length

Technical Field

The invention relates to the technical field of medical instruments, in particular to an optical system and a method for measuring the length of an eye axis.

Background

Nowadays, more and more old people suffering from cataract eye diseases are transplanted with artificial lenses, and the artificial lenses are an effective scheme for treating cataract widely used at present. However, the parameters required for calculation of the intraocular lens are more demanding, such as cornea anterior and posterior surface curvature, cornea thickness, anterior chamber depth, lens thickness, lens anterior and posterior surface curvature, eye axis length, white-to-white distance, pupil diameter, etc. The measured parameters are more, but a plurality of medical devices are often needed to detect the measured parameters, so that the complete data can be obtained. Thus, if one device can be realized, the medical device can obtain the data, and for the detection of a patient, the convenience of measurement can be improved, and the accuracy of measurement can be improved. In addition, along with the increase of the number of teenagers and the number of myopia, the situation of myopia prevention and control is more and more severe, and the measurement of the eye axis length is an important reference index of myopia prevention and control, so the device for simply and conveniently measuring a plurality of indexes of ophthalmology is a trend of development of ophthalmology medical equipment.

Optical coherence tomography (OCT, optical Coherence Tomography) is an emerging optical imaging technique, and compared with the traditional clinical imaging means, has the advantages of high resolution, high imaging speed, no radiation damage, moderate price, compact structure and the like, and is an important potential tool for basic medical research and clinical diagnosis application. Currently, among a variety of ophthalmic apparatuses using optical instruments, OCT apparatuses for ophthalmic examination and treatment have become an ophthalmic apparatus indispensable for diagnosis of ophthalmic diseases.

In patent document 201911073986.4, the influence of eye movement in the eye axial length measurement process is corrected by using side eye cornea photographing imaging, but side eye cornea photographing imaging is easily influenced by ambient light, and cornea is transparent, and cornea vertex is difficult to identify, so that error is large. In patent documents 201410135999.0 and 202011120798.5, the eye axial length is measured by performing OCT imaging of the cornea and the eye posterior segment by using OCT switching techniques of the eye anterior and posterior segments, respectively, but the OCT switching process of the eye anterior and posterior segments requires a long time, and thus there is a possibility that the eye movement is affected, resulting in a decrease in reliability of the eye axial length measurement.

The foregoing background is only for the purpose of facilitating an understanding of the principles and concepts of the invention and is not necessarily in the prior art to the present application and is not intended to be used as an admission that such background is not entitled to antedate such novelty and creativity by the present application without undue evidence prior to the present application.

Disclosure of Invention

In order to solve the technical problems, the invention provides an optical system and a method for measuring the eye axial length, which avoid the influence of eye movement of a person to be measured and improve the eye axial length measurement precision.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

in a first aspect, the invention discloses an optical system for measuring the axial length of an eye, comprising an OCT light source module, an OCT imaging module, an OCT sample arm module for posterior segment of the eye and an anterior segment fracture imaging assembly, wherein:

the OCT light source module is used for providing measuring light, the measuring light passes through the OCT sample arm module of the posterior segment and then enters the eye fundus of the human eye to be measured, and the OCT imaging module receives the measuring light returned by the eye fundus of the human eye to be measured so as to acquire an OCT image of the posterior segment;

the anterior ocular segment crack imaging assembly comprises an anterior ocular segment crack light source module, an anterior ocular segment crack imaging module and an anterior ocular segment crack imaging adjustment light path module, wherein the anterior ocular segment crack light source module is used for providing crack light, the crack light passes through the anterior ocular segment crack imaging adjustment light path module and then is focused on an anterior ocular segment of a human to be tested, and the anterior ocular segment crack imaging module receives the returned crack light to acquire an anterior ocular segment crack image;

and respectively acquiring first optical path data and second optical path data by utilizing the OCT image of the posterior segment and the fracture image of the anterior segment, and calculating the axial length of the eye by utilizing the first optical path data and the second optical path data.

Preferably, the anterior ocular segment crack imaging module comprises an anterior ocular segment crack imaging lens (1801) and an anterior ocular segment crack imaging device (1803), wherein the crack light emitted by the anterior ocular segment crack light source module is focused on the anterior ocular segment of the human to be tested and returns to the anterior ocular segment crack light signal to pass through the anterior ocular segment crack imaging lens (1801) and is received by the anterior ocular segment crack imaging device (1803), and the anterior ocular segment crack imaging device (1803) obtains an anterior ocular segment crack image according to the anterior ocular segment crack light signal.

Preferably, the anterior ocular segment crack imaging adjustment light path module comprises an objective lens (1305), wherein the objective lens (1305) is located on a light path in a first direction, the light path in the first direction is perpendicular to the human eye to be measured, and the anterior ocular segment crack imaging lens (1801) and the anterior ocular segment crack imaging device (1803) are respectively arranged below the objective lens (1305).

Preferably, the anterior ocular segment slit light source module comprises an anterior ocular segment slit light source (1809) and a front spectroscope (1303), wherein the anterior ocular segment slit light source (1809) emits slit light, and the slit light passes through the front spectroscope (1303), then passes through the anterior ocular segment slit imaging adjustment light path module and is focused on the anterior ocular segment of the human to be tested.

Preferably, the posterior segment OCT sample arm module includes an optical path scanning device (1109) and a posterior segment OCT imaging adjustment optical path unit, the posterior segment OCT imaging adjustment optical path unit and an anterior segment OCT insertion mirror (1501) form an anterior segment OCT imaging adjustment optical path unit, the anterior segment fracture imaging adjustment optical path module adopts the anterior segment OCT imaging adjustment optical path unit, and the anterior segment fracture light source module adopts the OCT light source module and the optical path scanning device (1109) to generate fracture light, wherein measurement light provided by the OCT light source module emits fracture light after one-dimensional scanning by the optical path scanning device (1109) and is focused on an anterior segment of a human eye to be measured after passing through the anterior segment OCT imaging adjustment optical path unit.

Preferably, the posterior segment OCT sample arm module includes an optical path scanning device (1109) and an optical path unit for adjusting the OCT imaging of the posterior segment, the optical path unit for adjusting the OCT imaging of the posterior segment and the OCT insertion mirror (1501) of the anterior segment form an optical path unit for adjusting the OCT imaging of the anterior segment, the optical path unit for adjusting the OCT imaging of the anterior segment is adopted by the anterior segment fracture imaging adjustment optical path module, the anterior segment fracture light source module adopts an anterior segment fracture light source (3809), a wavelength division multiplexer (3807), an optical fiber (1106) and the optical path scanning device (1109) to generate fracture light, the light output by the anterior segment fracture light source (3809) is coupled by the wavelength division multiplexer (3807) and then transmitted to the optical fiber (1106), and the light output by the optical fiber (1106) is emitted fracture light after one-dimensional scanning by the optical path scanning device (1109) and passes through the anterior segment OCT imaging adjustment optical path unit and then focuses on the anterior segment of the eye to be measured.

Preferably, the posterior segment OCT sample arm module includes an optical path scanning device (1109) and an optical path unit for adjusting the OCT imaging of the posterior segment, the optical path unit for adjusting the OCT imaging of the posterior segment and the OCT insertion mirror (1501) of the anterior segment form an optical path unit for adjusting the OCT imaging of the anterior segment, the optical path unit for adjusting the OCT imaging of the anterior segment is adopted by the optical path module for adjusting the OCT imaging of the anterior segment, the optical path unit for generating the slit light by the slit light source (4809) of the anterior segment, a parallel optical fiber (2106) and the optical path scanning device (1109), the light output by the slit light source (3809) of the anterior segment passes through the parallel optical fiber (2106), and the light output by the parallel optical fiber (2106) emits the slit light after one-dimensional scanning by the optical path scanning device (1109) and passes through the optical path unit for adjusting the OCT imaging of the anterior segment and focuses on the anterior segment of the eye to be measured.

Preferably, the optical path unit for adjusting the OCT imaging of the posterior segment of the eye comprises an OCT field lens (1301), a front spectroscope (1303) and an objective lens (1305); measuring light provided by the OCT light source module passes through an OCT field lens (1301) of a posterior segment after being reflected by the light path scanning device (1109), then is reflected to the objective lens (1305) by the front dichroic mirror (1303), and is converged on the fundus of the eye to be tested by the eye to return an optical back segment signal to be transmitted to the OCT imaging module, and the OCT imaging module acquires an OCT image of the posterior segment according to the optical back segment signal;

The anterior ocular segment OCT imaging adjustment light path unit is formed by inserting an anterior ocular segment OCT insertion mirror (1501) on a light path formed by the posterior ocular segment OCT imaging adjustment light path unit, and after the slit light sequentially passes through an posterior ocular segment OCT field mirror (1301) and the anterior ocular segment OCT insertion mirror (1501), the slit light is reflected to the eye objective lens (1305) through the prepositive dichroic mirror (1303) and converged on the anterior ocular segment of a person to be detected so as to return an anterior ocular segment slit light signal to be transmitted to the anterior ocular segment slit imaging module, and the anterior ocular segment slit imaging module acquires an anterior ocular segment slit image according to the anterior ocular segment slit light signal.

Preferably, the first optical path data refers to an optical path hRetinal from the top end of the posterior segment OCT image to the retina signal in the posterior segment OCT image of the human eye to be measured, and the second optical path data refers to an optical path hCornea from the top end of the anterior segment slit image to the cornea vertex of the human eye to be measured;

calculating an eye axis length by using the first optical path data and the second optical path data, including: and calculating the eye axis length Leye of the human eye to be detected according to the optical path change X of the eye posterior segment OCT sample arm module, the measured optical path hRetinal and the measured optical path hCornea when the eye posterior segment OCT image of the human eye to be detected is acquired.

In a second aspect, the invention discloses a method for measuring the length of the eye axis, which is characterized in that the optical system in the first aspect is adopted to measure the length of the eye axis of the human eye to be measured, and the method comprises the following steps:

acquiring an eye posterior segment OCT image of a human eye to be detected, so as to measure an optical path hRetinal from the top end of the eye posterior segment OCT image to a retina signal in the eye posterior segment OCT image according to the eye posterior segment OCT image of the human eye to be detected;

acquiring an anterior ocular segment crack image of a human eye to be detected, and measuring an optical path hCornea from the top end of the anterior ocular segment crack image to the corneal vertex of the human eye to be detected according to the anterior ocular segment crack image of the human eye to be detected;

and calculating the eye axis length Leye of the human eye to be detected according to the optical path change X of the eye posterior segment OCT sample arm module, the measured optical path hRetinal and the measured optical path hCornea when the eye posterior segment OCT image of the human eye to be detected is acquired.

Preferably, the eye axis length Leye of the human eye to be tested is calculated by the following formula:

Leye＝△L+X-hCornea+hRetinal；

wherein DeltaL represents the spatial distance between the top end of the OCT image of the posterior segment of the eye and the top end of the fracture image of the anterior segment of the eye, and X represents the optical path change amount of the OCT sample arm module of the posterior segment of the eye when the OCT image of the posterior segment of the eye of the person to be detected is acquired.

Compared with the prior art, the invention has the beneficial effects that: according to the optical system and the method for measuring the eye axial length, the eye axial length is further measured by respectively acquiring the OCT image of the posterior segment and the fracture image of the anterior segment, wherein the accurate positioning of the cornea position is realized through the fracture imaging of the anterior segment, and the switching time can be reduced or even no switching is needed by combining with the OCT image acquisition of the posterior segment, so that the influence of eye movement of a person to be measured is avoided, and the eye axial length measurement precision is improved.

In a further scheme, by adding an anterior ocular segment slit light source which independently generates slit light, and adopting different imaging schemes for acquiring an posterior ocular segment OCT image and an anterior ocular segment slit image, the two images can be acquired simultaneously, thereby avoiding the influence of eye movement of a human eye to be detected to the greatest extent and further improving the measurement accuracy of the axial length of the eye.

In a further scheme, an OCT light source module or an additionally arranged anterior segment fracture light source is combined with the light path scanning device to generate fracture light, and an anterior segment OCT imaging adjustment light path unit is further combined, so that the fracture light can be focused on the cornea of a human eye to be detected, and an anterior segment fracture image is further acquired; according to the scheme, one path of optical path is not required to be additionally debugged, so that the system debugging difficulty can be reduced, and the system debugging speed can be improved; and moreover, only the OCT insertion mirror of the anterior segment of the eye is required to be adjusted between the OCT image of the posterior segment of the eye and the fracture image of the anterior segment of the eye, the optical path is not required to be adjusted, the switching time is shorter, and compared with the switching time in the prior art, the influence of eye movement during measuring the axial length of the eye is easier to avoid.

Drawings

FIG. 1 is a schematic diagram of an ophthalmic optical biometric system according to a first embodiment of the present invention;

FIG. 2 is an optical path diagram of a posterior segment OCT imaging system of the ophthalmic optical biometric system of FIG. 1;

FIG. 3 is an optical path diagram of an anterior ocular segment OCT imaging system of the ophthalmic optical biometric system of FIG. 1;

FIG. 4a is a front view of an anterior ocular segment camera module of the ophthalmic optical biometric system of FIG. 1;

FIG. 4b is a top view of an anterior ocular segment camera module of the ophthalmic optical biometric system of FIG. 1;

FIG. 5 is a light path diagram of an anterior ocular segment fracture imaging of the ophthalmic optical biometric system of FIG. 1;

FIG. 6 is a schematic view of a fixation optics module of the ophthalmic optical biometric system of FIG. 1;

FIG. 7 is a schematic illustration of measurement of eye axis length;

FIG. 8 is a schematic diagram of an ophthalmic optical biometric system according to a second embodiment of the present invention;

FIG. 9 is a light path diagram of anterior ocular segment fracture imaging of the ophthalmic optical biometric system of FIG. 8;

FIG. 10 is a schematic view of a fixation optics module of the ophthalmic optical biometric system of FIG. 8;

FIG. 11 is a schematic diagram of an ophthalmic optical biometric system according to a third embodiment of the present invention;

FIG. 12 is a schematic view of the structure of an optical fiber of the ophthalmic optical biometric system of FIG. 11;

FIG. 13 is an optical path diagram of a posterior segment OCT imaging system of the ophthalmic optical biometric system of FIG. 11;

FIG. 14 is an optical path diagram of an anterior ocular segment OCT imaging system of the ophthalmic optical biometric system of FIG. 11;

FIG. 15 is a light path diagram of anterior ocular segment fracture imaging of the ophthalmic optical biometric system of FIG. 11;

FIG. 16 is a schematic diagram of an ophthalmic optical biometric system according to a fourth embodiment of the present invention;

FIG. 17 is a schematic diagram of the structure of the parallel optical fibers of the ophthalmic optical biometric system of FIG. 16;

FIG. 18 is a schematic diagram of a prior art parallel optical fiber;

fig. 19 is a light path diagram of anterior ocular segment fracture imaging of the ophthalmic optical biometric system of fig. 16.

Reference numerals illustrate: 10. a probe module; 1101. an OCT light source; 1103. an optical fiber coupler; 1105. a polarization controller; 1106. an optical fiber; 11061. a core; 11063. a cladding layer; 11065. a sheath; 1107. an optical fiber collimator; 1109. an optical path scanning device; 11091. an X-direction scanning device; 11093. a Y-direction scanning device; 1120. a reference arm module; 1141. a detector; 1143. a computer; 1301. posterior segment OCT field lens; 1303. a front spectroscope; 1305. an objective lens; 1501. anterior ocular segment OCT insertion mirror; 1701. a fixation light source; 1703. a gaze optical path lens; 18. a combination module; 1801. anterior ocular segment fissure imaging lens; 1803. anterior ocular segment fissure imaging means; 1807. angular beam splitters; 1809. anterior ocular segment fissure light source; 1901. an illumination light source; 1903. an iridescent relay lens; 1905. an iridescent beam splitter; 1907. anterior ocular segment image pickup mirror; 1909. anterior ocular segment image pickup means; E. human eyes to be measured; er, fundus; l1, optical axis; 2106. parallel optical fibers; 21061. OCT optical path fiber core; 21062. anterior ocular segment fissure illumination optical path fiber core; 21063. OCT light path cladding; 21065. a sheath; 3106. a dual-core optical fiber; 31061. a fiber core; 31062. a fiber core; 31063. an optical fiber cladding; 31064. an optical fiber cladding; 31065. a sheath; 31066. a sheath; 31069. a large sheath; 3807. a wavelength division multiplexer; 3809. anterior ocular segment fissure light source; 4809. anterior segment fissure light source.

Detailed Description

The invention will be described in further detail with reference to the following detailed description and with reference to the accompanying drawings. Wherein like reference numerals refer to like parts throughout unless otherwise specified. It should be emphasized that the following description is merely exemplary in nature and is in no way intended to limit the scope of the invention or its applications.

The invention will be better understood by the following detailed description of specific embodiments with reference to the accompanying drawings, but the following examples do not limit the scope of the invention. In addition, it should be noted that the illustrations provided in the following embodiments merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings rather than being drawn according to the number, shape and size of the components in actual implementation, and the shapes, numbers and proportions of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.

It is to be understood that the terms "upper," "lower," "front," "rear," "inner," "outer," "left," "right," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate describing embodiments of the present invention and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

The ophthalmic optical biological measurement system provided by the invention is mainly used for measuring relevant optical parameters of a patient's eye and checking the patient's eye, and can be used for measuring a plurality of ophthalmic relevant parameters such as OCT (optical coherence tomography) images of a front section of the eye, OCT images of a rear section of the eye, photographing of the front section of the eye, axial length of the eye, depth of an anterior chamber, white-to-white distance and the like. The method is mainly based on an optical coherence tomography technology, and is combined with an OCT acquisition technology of front and rear sections, an anterior segment fracture imaging technology and an anterior segment photographing technology to realize measurement of relevant ophthalmic parameters such as human eye axial length. By the iris recognition technology, the automatic recognition technology of the front section OCT image, the automatic recognition technology of the rear section OCT image and the like, the full-automatic detection of the system is realized. The eye axial length measuring technology is realized by precisely positioning the cornea (namely anterior segment) position through the anterior segment fracture imaging of the eye and combining with the posterior segment OCT acquisition technology.

The invention adopts the OCT system with rapid switching of front and rear sections, combines with the technology of photographing and automatic identification of the front section of eyes, and can solve the detection of numerous optical parameters of human eyes; thereby meeting the measurement requirements of different parts, being capable of obtaining accurate data of a plurality of important human eye parameters and meeting the clinical diagnosis requirements of doctors. The full-automatic detection of the system is realized by the iris recognition technology, the anterior segment OCT image automatic recognition technology, the posterior segment OCT image automatic recognition technology and the like.

The first preferred embodiment of the invention discloses an optical system for measuring the axial length of an eye, which comprises an OCT light source module, an OCT imaging module, an OCT sample arm module for posterior segment of the eye and an anterior segment fracture imaging assembly, wherein: the OCT light source module is used for providing measuring light, the measuring light passes through the OCT sample arm module of the posterior segment of the eye and then enters the fundus of the eye to be measured, and the OCT imaging module receives the measuring light returned by the fundus of the eye to be measured so as to acquire an OCT image of the posterior segment of the eye; the anterior ocular segment slit imaging assembly comprises an anterior ocular segment slit light source module, an anterior ocular segment slit imaging module and an anterior ocular segment slit imaging adjustment light path module, wherein the anterior ocular segment slit light source module is used for providing slit light, the slit light passes through the anterior ocular segment slit imaging adjustment light path module and then is focused on the anterior ocular segment of a person to be tested, and the anterior ocular segment slit imaging module receives the returned slit light so as to acquire an anterior ocular segment slit image; and respectively acquiring first optical path data and second optical path data by utilizing the OCT image of the posterior segment and the fracture image of the anterior segment, and calculating the axial length of the eye by utilizing the first optical path data and the second optical path data.

The first optical path data refers to an optical path hRetinal from the top end of an eye posterior segment OCT image to a retina signal in the eye posterior segment OCT image, and the second optical path data refers to an optical path hCornea from the top end of an eye anterior segment slit image to the cornea vertex; calculating an eye axis length using the first optical path data and the second optical path data, comprising: and calculating the eye axial length Leye of the human eye to be measured according to the optical path change X of the eye posterior segment OCT sample arm module, the measured optical path hRetinal and the measured optical path hCornea when the eye posterior segment OCT image of the human eye to be measured is acquired.

The anterior segment slit imaging module comprises an anterior segment slit imaging lens 1801 and an anterior segment slit imaging device 1803, slit light emitted by the anterior segment slit light source module is focused on the anterior segment of the human eye to be detected, returns anterior segment slit light signals, passes through the anterior segment slit imaging lens 1801, is received by the anterior segment slit imaging device 1803, and the anterior segment slit imaging device 1803 obtains anterior segment slit images according to the anterior segment slit light signals. Further, the anterior segment fracture imaging adjustment light path module includes an objective lens 1305, the objective lens 1305 is located on a light path in a first direction, wherein the light path in the first direction is perpendicular to the eye to be measured, and the anterior segment fracture imaging lens 1801 and the anterior segment fracture imaging device 1803 are respectively disposed below the objective lens 1305. The anterior ocular segment fissure imaging module in the following embodiments one to four adopts this structure.

In some preferred embodiments, for example, in the first embodiment described below, the anterior segment slit light source module includes an anterior segment slit light source 1809 and a pre-beam splitter 1303, and the anterior segment slit light source 1809 emits slit light, which is focused on the anterior segment of the human eye to be measured after passing through the anterior segment slit imaging adjustment light path module after passing through the pre-beam splitter 1303. Specifically, the anterior ocular segment slit light source 1809 emits slit light, which is reflected by the angular beam splitter 1807, reflected by the iridescent beam splitter 1905, transmitted through the iridescent relay lens 1903 and the anterior spectroscope 1303, and focused on the anterior ocular segment of the human eye to be measured by the objective lens 1305.

In some preferred embodiments, for example, the second embodiment described below, the posterior segment OCT sample arm module includes an optical path scanning device 1109 and an posterior segment OCT imaging adjustment optical path unit, the posterior segment OCT imaging adjustment optical path unit and the anterior segment OCT insertion mirror 1501 form an anterior segment OCT imaging adjustment optical path unit, the anterior segment fracture imaging adjustment optical path module employs the anterior segment OCT imaging adjustment optical path unit, and the anterior segment fracture light source module employs the OCT light source module and the optical path scanning device 1109 to generate fracture light, where the measurement light provided by the OCT light source module emits fracture light after one-dimensional scanning by the optical path scanning device 1109 and is focused on the anterior segment of the human eye to be measured after passing through the anterior segment OCT imaging adjustment optical path unit.

In some preferred embodiments, for example, the following third embodiment, the posterior segment OCT sample arm module includes an optical path scanning device 1109 and an optical path unit for adjusting the OCT imaging of the posterior segment, the optical path unit for adjusting the OCT imaging of the posterior segment and the OCT insertion mirror 1501 form an optical path unit for adjusting the OCT imaging of the anterior segment, the optical path unit for adjusting the OCT imaging of the anterior segment is used for the OCT imaging of the anterior segment, the anterior segment slit light source module uses the anterior segment slit light source 3809, the wavelength division multiplexer 3807, the optical fiber 1106 and the optical path scanning device 1109 to generate slit light, the light output by the anterior segment slit light source 3809 is coupled by the wavelength division multiplexer 3807 and then transmitted to the optical fiber 1106, and the light beam output by the optical fiber 1106 is emitted after one-dimensional scanning by the optical path scanning device 1109 and is focused on the anterior segment of the eye to be measured after passing through the optical path unit for adjusting the OCT imaging of the anterior segment.

In some preferred embodiments, for example, the following fourth embodiment, the posterior segment OCT sample arm module includes an optical path scanning device 1109 and an optical path unit for adjusting OCT imaging of the posterior segment, where the optical path unit for adjusting OCT imaging of the posterior segment and the anterior segment OCT insertion mirror 1501 form an optical path unit for adjusting OCT imaging of the anterior segment, the optical path unit for adjusting OCT imaging of the anterior segment is used for adjusting OCT imaging of the anterior segment, the anterior segment slit light source module uses an anterior segment slit light source 4809, a parallel optical fiber 2106 and an optical path scanning device 1109 to generate slit light, the light output by the anterior segment slit light source 3809 passes through the parallel optical fiber 2106, and the light output by the parallel optical fiber 2106 emits slit light after one-dimensional scanning by the optical path scanning device 1109 and passes through the optical path unit for adjusting OCT imaging of the anterior segment and is focused on the anterior segment of the human eye to be measured.

Further, in the second, third, and fourth embodiments, the posterior segment OCT imaging adjustment optical path unit includes a posterior segment OCT field lens 1301, a front beam splitter 1303, and an objective lens 1305; the measuring light provided by the OCT light source module passes through the OCT field lens 1301 after being reflected by the light path scanning device 1109, then is reflected to the eye objective lens 1305 by the front dichroic mirror 1303, and is converged on the fundus of the eye to be measured by the eye to return an OCT optical signal to be transmitted to the OCT imaging module, and the OCT imaging module acquires an OCT image of the back eye according to the OCT optical signal; the anterior ocular segment OCT imaging adjustment light path unit is formed by inserting an anterior ocular segment OCT insertion mirror 1501 on a light path formed by the posterior ocular segment OCT imaging adjustment light path unit, and the slit light sequentially passes through the posterior ocular segment OCT field mirror 1301 and the anterior ocular segment OCT insertion mirror 1501, then is reflected to the eye objective lens 1305 by the front dichroic mirror 1303, is converged on the anterior ocular segment of the human to be detected, so as to return an anterior ocular segment slit light signal to be transmitted to an anterior ocular segment slit imaging module, and the anterior ocular segment slit imaging module acquires anterior ocular segment slit images according to the anterior ocular segment slit light signal.

The ophthalmic optical biometric system of the present invention is described in further detail below in connection with a number of specific embodiments.

Example 1

The first embodiment of the invention discloses an ophthalmic optical biological measurement system which comprises an OCT imaging module, an OCT sample arm module of a posterior segment, an OCT insertion mirror of an anterior segment, a fixation optical module, an anterior segment shooting module and an anterior segment crack imaging module. Wherein each module can play a corresponding function, some optical components among the modules are shared, and each module forms the ophthalmic optical biological measurement system through proper combination.

The computer 1143 controls the input and output of the eye anterior segment OCT insertion mirror 1501, and the optical path switching and OCT imaging of different parts of human eyes are realized by matching with the translation of the optical fiber collimator 1107 along the optical axis.

Referring to fig. 1, there is shown a block diagram of an ophthalmic optical biometric system according to a first embodiment of the present invention, wherein a probe module 10 comprises: the system comprises an eye posterior segment OCT sample arm module, an eye anterior segment OCT insertion mirror, a fixation optical module, an eye anterior segment shooting module and an eye anterior segment fracture imaging module. The whole probe module 10 is driven by 3 motors (not shown in the figure) and can realize X/Y/Z three-dimensional translation. In this embodiment, the X axis is defined as an axis perpendicular to the paper surface, the Y axis is defined as an axis parallel to the up-down direction of the paper surface, and the Z axis is defined as an axis parallel to the left-right direction of the paper surface, that is, the X axis and the Y axis directions refer to the horizontal axis and the vertical axis directions on the plane parallel to the outer surface of the human eye E to be measured, respectively, and the Z axis direction refers to the direction perpendicular to the plane parallel to the outer surface of the human eye E to be measured. The above definitions are provided for convenience of description and are not limited thereto.

(1) OCT imaging system

The OCT imaging module includes an OCT light source 1101, a fiber coupler 1103, a reference arm module 1120, a detector 1141, a computer 1143, a polarization controller 1105, and a sample arm module, where the output wavelength of the OCT light source 1101 is about near infrared light, and the sample arm module includes a posterior segment OCT sample arm module 130 and an anterior segment insertion mirror 1501. The computer 1143 is not a PC computer in a conventional sense, but is a circuit control and processing system capable of performing a set of functions such as operation, control, storage, display, etc.

The optical path of the OCT imaging module includes an OCT light source 1101 (a weak coherent light source may be employed) whose output light provides light to a sample arm module and a reference arm module 1120 via a fiber optic coupler 1103. The reference arm module 1120 has a known length, and the optical fiber coupler 1103 provides light to the reference arm module 1120 for retransmission to the optical fiber coupler 1103. The sample arm module provides light for the eye E to be tested, the light scattered back from the eye E to be tested is interfered in the optical fiber coupler 1103 by the light transmitted by the sample arm module, the polarization controller 1105 and the reference arm module 1120, the interfered light is detected by the detector 1141, and then processed by the computer 1143, and finally the OCT image of the eye E to be tested is displayed. The optical path scanning device 1109 is a two-dimensional scanning mechanism, and is composed of an X-direction scanning device 11091 and a Y-direction scanning device 11093, and scans a sample (human eye to be measured) with the optical path scanning device 1109 to realize tomographic imaging of OCT.

(2) OCT imaging system for posterior segment of eye

As shown in fig. 2, is an optical path diagram of a posterior segment OCT imaging system. The posterior segment OCT sample arm module 130 includes an optical path scanning device 1109 and a posterior segment OCT imaging adjustment optical path unit including an optical fiber collimator 1107, a posterior segment OCT field lens 1301, a front beam splitter 1303, and an objective lens 1305. The optical path scanning device 1109 may be a one-dimensional optical path switching scanning device, or may be two-dimensional or even three-dimensional; the one-dimensional to multi-dimensional scanning of the eye E to be detected is realized by the optical path scanning device 1109. The optical fiber exits through the sample arm fiber head (not shown) adjacent to the fiber collimator 1107; the sample arm optical fiber head and the optical fiber collimating mirror 1107 are driven by a motor to translate along the main optical axis of the optical fiber collimating mirror 1107, so that the optical path of the sample arm optical path is changed. Similarly, the matching of the optical paths of the sample arm and the reference arm can also be realized by changing the optical path of the reference arm; wherein the optical fiber is connected to the sample arm fiber head.

When performing OCT imaging of the posterior segment of the eye, light emitted from the fiber collimator 1107 is reflected by the optical path scanning device 1109. At this time, the optical path scanning device 1109 is controlled by the computer 1143, and the light beam passes through the optical path scanning device 1109, then passes through the OCT field lens 1301, then passes through the pre-beam splitter 1303, and then is reflected to the objective lens 1305, and finally passes through the eye E to be tested and is converged to the eye fundus Er to be tested. The detection light beam of the OCT imaging light path system of the posterior segment of the eye meets the requirement that the central line of the scanning light beam is converged near the pupil of the human eye, and the OCT light beam is focused on the fundus Er of the human eye at any moment.

The OCT beam can be focused on the fundus Er of human eyes by adjusting the objective lens 1305 for different eyes (different diopters). That is, the light beam is focused on the retina, so that the signal-to-noise ratio and the transverse resolution of OCT images can be effectively improved during retina measurement.

The pre-beam splitter 1303 can reflect the signal light emitted from the OCT light source 1101 and transmit the fixation light emitted from the fixation light source 1701 in the fixation optical module; transmitting light emitted by an anterior ocular segment fracture light source 1809 in an anterior ocular segment fracture imaging module; but also transmits illumination light from the illumination light source 1901 in the anterior segment imaging module.

At this time, the anterior ocular segment OCT insertion mirror 1501 is controlled by the computer 1143 to switch out the posterior ocular segment OCT imaging optical path.

When fundus is measured, scanning is performed by the X-direction scanning device 11091 and the Y-direction scanning device 11093; the optical path matching for the eyeground of different eyes is realized by combining the integral translation of the sample arm optical fiber head (not shown) through the optical fiber collimating lens 1107; the eye objective 1305 translates along the optical axis to adjust and bend for different eyes; finally, the acquisition of OCT images of the posterior segment of the eye is realized, so that important parameters of human eye structures such as retina thickness and the like are obtained.

(3) OCT imaging system for anterior ocular segment

As shown in fig. 2, is an optical path diagram of an anterior ocular segment OCT imaging system. The posterior segment OCT imaging adjustment optical path unit and the anterior segment OCT insertion mirror 1501 form an anterior segment OCT imaging adjustment optical path unit, that is, the anterior segment OCT imaging adjustment optical path unit includes an optical fiber collimator 1107, a posterior segment OCT field mirror 1301, an anterior segment OCT insertion mirror 1501, a front beam splitter 1303, and an objective lens 1305. The anterior ocular segment OCT imaging can be performed by the cooperation of the optical path scanning device 1109 and the anterior ocular segment OCT imaging adjustment optical path unit.

When performing OCT imaging of the anterior segment of the eye, the light emitted from the optical fiber collimator 1107 is reflected by the optical path scanning device 1109, transmitted through the posterior segment OCT field mirror 1301, the anterior segment OCT insertion mirror 1501, reflected by the anterior beam splitter 1303, transmitted through the objective lens 1305, and finally converged to the anterior segment of the eye E to be measured (i.e., the cornea of the eye to be measured). The detection beam of the OCT imaging optical path system of the anterior ocular segment meets the requirement that the OCT beam is focused on the anterior ocular segment of a human eye.

At this time, the anterior ocular segment OCT insertion mirror 1501 is controlled by the computer 1143 to be inserted into the optical path.

When the front and back surfaces of the cornea and the crystalline lens are measured, the OCT light beam is focused on the middle area of the anterior segment of the eye, and the signal to noise ratio and the transverse resolution of OCT images can be effectively improved when the front and back surfaces of the cornea and the crystalline lens are measured.

When measuring the OCT image of the anterior ocular segment, scanning by an optical path scanning device 1109; the optical path matching required by OCT measurement is realized by combining the integral translation of a sample arm optical fiber head (not shown) through an optical fiber collimator 1107; focusing is achieved by translation of the objective 1305 along the optical axis L1 or translation of the entire probe module 10 along the optical axis L1. OCT images of the front and back surfaces of the cornea and the lens can be obtained through the matching of the optical path scanning device 1109 and the OCT imaging adjustment optical path unit of the anterior segment of the eye, so that important parameters of the structure of the human eye such as the curvature of the front and back surfaces of the cornea, the thickness of the cornea, the depth of the anterior chamber, the thickness of the lens, the curvature of the front and back surfaces of the lens and the like can be obtained.

(4) Anterior ocular segment camera module

As shown in fig. 4a and 4b, a front view and a top view of the anterior ocular segment imaging module are shown, respectively.

The module can be used for iris preview so as to guide doctors to operate instruments and lead the probe light path to be aligned with eyes of people to be tested. Or automatically identifying the center of the iris or the center of the pupil, and guiding the probe module 10 to automatically perform three-dimensional movement, so as to realize the alignment of the pupil of the human eye to be detected, thereby realizing the detection of the human eye to be detected.

The light emitted from the illumination light source 1901 (infrared light) is irradiated to the anterior chamber of the human eye E to be measured, and the light is reflected by the tissue of the anterior chamber. The reflected light passes through the objective 1305, the front beam splitter 1303, the iris relay 1903, the iris beam splitter 1905, the anterior segment image pickup lens 1907, and the anterior segment image pickup device 1909.

The examiner uses a chin rest device (not shown) to fix the examinee's head and let the examinee fix the fixation mark of the fixation system so as to fix the examinee's eyes. Then, the detector controls the movement of the chin rest apparatus, the probe 10, and the like by the joystick while observing the display screen of the computer 1143 so that the anterior ocular segment of the eye E to be inspected enters the anterior ocular segment imaging device 1909, and an anterior ocular segment image is presented on the display screen of the computer 1143. Or automatically identifying the center of the iris or the center of the pupil, and guiding the probe 10 to automatically perform three-dimensional movement, so as to realize the alignment of the pupil of the human eye to be detected, thereby realizing the detection of the human eye to be detected.

Important parameters of human eye structures such as white-to-white distance and pupil diameter can be obtained through the anterior ocular segment image pickup module 190.

The distribution of the illumination sources 1901 in fig. 4b is only illustrative, and other embodiments may use other distribution methods, and the number of the illumination sources 1901 may be 1 or more, as long as the illumination sources 1901 illuminate the anterior segment of the human eye to be measured.

The iridescent beam splitter 1905 transmits illumination light emitted from the illumination light source 1901 in the anterior ocular segment image capturing module 190, and also reflects fixation light emitted from the fixation light source 1701 in the fixation optical module, and reflects light emitted from the anterior ocular segment slit light source 1809 in the anterior ocular segment slit imaging module.

(5) Anterior segment fracture imaging module

As shown in fig. 5, a schematic diagram of an anterior ocular segment fissure imaging module is shown. The anterior segment slit imaging module comprises a combination module 18, a front spectroscope 1303, an iris relay lens 1903, an iris spectroscope 1905, an angle spectroscope 1807 and an anterior segment slit light source 1809, wherein the combination module 18 is composed of an eye objective 1305, an anterior segment slit imaging lens 1801 and an anterior segment slit imaging device 1803. The combination module 18 is driven by a motor (not shown) that is independent of the 3 motors described above, and is movable in the Z direction to achieve refractive adjustment.

The anterior ocular segment slit light source 1809 emits light through a knife edge or slit to generate slit light or slit light. The slit light is reflected by the angular beam splitter 1807 and the irid beam splitter 1905, transmitted through the irid relay lens 1903 and the front beam splitter 1303, and focused on the front section of the human eye to be measured by the objective lens 1305. The anterior segment slit light passes through anterior segment tissue, is scattered by tissue such as cornea and crystal, passes through anterior segment slit imaging lens 1801, and is finally captured by anterior segment slit imaging device 1803.

The anterior ocular segment fracture imaging optical path (including anterior ocular segment fracture imaging lens 1801 and anterior ocular segment fracture imaging device 1803) is preferably distributed under the objective lens 1305. If the lens is disposed on the left/right side of the probe 10 in the X direction, the lens is not suitable for use with both eyes, and if the lens is disposed above the objective lens 1305, the lens is likely to be blocked by eyelid.

In some embodiments, the anterior segment fracture imaging device 1803 is only used to capture anterior segment fracture images near the cornea position of the human eye to be detected, and the imaging range is smaller, but the imaging precision is high. The spatial position of the cornea can be accurately positioned through the anterior segment fracture image. For example, the thickness of the cornea is about 550um, and if the imaging range of the anterior ocular segment fissure in the Z direction is 0.5-10 mm, the positioning accuracy of the cornea position can be effectively improved. In other embodiments, the imaging range of anterior segment fissure imaging device 1803 is increased, and anterior chamber depth, and even crystal thickness, data may be obtained.

In this embodiment, the optical paths of the anterior segment fissure image capturing are distributed at an oblique angle, so that the anterior segment fissure imaging module can accurately identify the Z-direction position of the eye to be detected in combination with the anterior segment image capturing module, and the axial length of the eye to be detected can be obtained in combination with the acquired posterior segment OCT image.

The angular beam splitter 1807 reflects light emitted from the anterior segment slit light source 1809 in the anterior segment slit imaging module and transmits fixation light emitted from the fixation light source 1701 in the fixation optical module.

(6) Fixation optical module

As shown in fig. 6, a schematic view of the fixation optical module is shown. The fixation light source 1701 in the fixation optical module is used for fixation marks (internal fixation marks) for fixation of the eye E to be measured. Light from the fixation light source 1701 is reflected by the fixation light path lens 1703 and the angular beam splitter 1807 via the irid beam splitter 1905, transmitted through the irid relay lens 1903 and the front beam splitter 1303, and then enters the eye E to be measured via the objective lens 1305. Finally, the internal fixation index is projected onto the fundus Er of the human eye E to be measured.

The fixation light source 1701 may employ a single point LED, or an LCD screen, an OLED screen, or an LED array screen, or the like.

When OCT imaging is carried out on the posterior segment of the eye, when different eyes observe the fixation point, the definition degree of the fixation point is different, which causes discomfort to the tested person in fixation, and is inconvenient for fixation and fixation of the eye E to be tested. The optical path during OCT imaging of the posterior segment of the eye can be focused on the fundus Er (fundus retina) of the human eye E to be detected after being adjusted and bent by the eye objective 1305, namely the human eye can see a clear scanning line. Since the optical path for OCT imaging of the posterior segment of the eye and the optical path for fixation share the objective 1305, the fixation target can be seen clearly for different eyes.

(7) Measurement of eye axis length

Because the detection depth of the OCT system is limited, one-time imaging detection from cornea to fundus retina cannot be realized, the embodiment combines the anterior segment fracture imaging and posterior segment OCT imaging technology, the cornea position of the human eye to be detected is determined through the anterior segment fracture imaging, and the fundus position of the human eye to be detected is determined through the posterior segment OCT imaging, so that the measurement of the axial length of the eye is realized.

As shown in fig. 7, er represents the fundus of the eye to be measured, ec represents the corneal vertex of the eye to be measured, and X represents the amount of optical path change of the optical path of the sample arm when the OCT image of the posterior segment of the eye to be measured is measured, which is changed by the optical path adjusting device (including the optical fiber collimator 1107 and the optical fiber head not shown in the figure); CDK represents the spatial position corresponding to the top of the anterior segment fissure image; RDK1 represents the spatial position corresponding to the top end of the OCT image of the posterior segment of the eye when the optical path regulating device is at the reset position; RDK2 represents the spatial position corresponding to the top end of the OCT image of the eye posterior segment when the optical path length of the sample arm is changed by the optical path length change amount X by the optical path length adjusting device when the OCT image of the eye posterior segment of the human eye to be measured is measured; hCornea represents the optical path from the top of the anterior segment slit image to the corneal vertex Ec of the human eye to be measured in the anterior segment slit image; hRetinal represents the optical path from the tip of the posterior segment OCT image to the retinal signal in the posterior segment OCT image. The 3 rectangular boxes shown in fig. 7, wherein the left 2 represent the OCT measurement range of the posterior segment, are only schematic, and the actual scan area may be a fan-shaped structure; the right rectangular box characterizes the anterior ocular segment fracture image taken by anterior ocular segment fracture imaging.

When the anterior ocular segment slit image is photographed, the focusing position of the slit light generated by the anterior ocular segment slit light source 1809 and the spatial position or spatial range that can be photographed by the anterior ocular segment slit photographing optical path are determined during system debugging, that is, the spatial distance from the spatial position CDK corresponding to the top end of the anterior ocular segment slit image to the objective lens 1305 in fig. 7 is determined during system debugging; therefore, if the human eye to be measured slightly moves forwards and backwards, but does not exceed the imaging range of the anterior segment fracture, the cornea space position can be determined by identifying the cornea position shot in the anterior segment fracture image.

When measuring OCT images of posterior segments of eyes, because the axial lengths of eyes are not the same, but the length of a reference arm of the OCT system is fixed, the embodiment adopts the following method to realize the measurement of retina with different depths: (a) The optical path adjusting device is added, so that an equal interference surface of OCT imaging of the posterior segment of the eye moves; (b) The optical fiber collimator 1107 and the sample arm optical fiber head are integrally translated along the optical axis; (c) The right-angle prism or the pyramid prism is added to enable the light path to be folded for a plurality of times, and then the light path is changed in a mode of translating the right-angle prism or the pyramid prism. The three implementation methods can be used simultaneously or alternatively.

The OCT system finds the retina signal of the posterior segment of the eye, and the optical path change amount of the optical path adjusting device relative to the reset position is X. That is, when the optical path device changes the optical path distance of the sample arm to X, the spatial position corresponding to the top end of the OCT image of the posterior segment of the eye is shifted from RDK1 to RDK2, where the distance between RDK1 and RDK2 is X, as shown in fig. 7.

The optical path change X of the optical path device can be measured by adopting various methods, such as a stepping motor and a voice coil motor, and the movement amount is calculated; or calculating the moving amount by using a grating ruler, a capacitance grating ruler and the like.

In addition, when the optical path adjusting device is at the reset position, the spatial distance between the spatial position RDK1 corresponding to the tip of the OCT image of the posterior segment of the eye and the objective lens 1305 is determined during system debugging. Therefore, the spatial distance Δl between RDK1 (spatial position corresponding to the tip of the posterior segment OCT image) and CDK (spatial position corresponding to the tip of the anterior segment fracture image) is determined at the time of system debugging.

Thus, by measuring the posterior segment OCT image and anterior segment fissure imaging, the human eye axial length Leye can be obtained:

Leye＝△L+X-hCornea+hRetinal，

where hCornea can be measured from anterior ocular segment fissure images and hRetinal can be measured from posterior ocular segment OCT images.

Because the lengths of the eye axes of different eyes are different, in order to measure the front and rear sections of the eye E to be measured, the optical path length of the sample arm or the reference arm needs to be changed to implement OCT coherent imaging (in this embodiment, the optical path length of the sample arm is changed as an example). Changing the optical path also needs to satisfy the different detection depth of OCT system and the different eye axis length of human eye, so it is difficult to realize fast switching to change the optical path. For example, an optical path adjusting device is adopted, and the fast switching cannot be realized by virtue of the translation of a motor, so that the optical path requirement of the front and rear section positions of the human eye is met. Therefore, in this embodiment, the axial length of the eye to be measured is measured by adopting a scheme of combining anterior segment fracture imaging with posterior segment OCT imaging.

Because the anterior segment fracture imaging and the posterior segment OCT imaging adopt different imaging schemes (the OCT system is not required to switch the anterior segment optical path and the posterior segment optical path), the two can be used for simultaneously acquiring images, thereby avoiding the influence of eye movement of the human eye to be detected and improving the measurement precision of the eye axial length.

In this embodiment, the determination of the cornea position adopts anterior ocular segment fracture imaging, and the recognition of the fundus position adopts posterior ocular segment OCT imaging technology, which can work simultaneously and acquire images simultaneously, and there is no time for switching the images, so that the influence of eye movement can be effectively avoided, and more accurate eye axial length data can be obtained. And the front and rear section images are acquired by one-time measurement, so that the operation of doctors is facilitated, the diagnosis speed is improved, and the interaction experience of doctors and patients is improved. In addition, the detection of a plurality of human eye key parameters such as cornea, anterior chamber depth, eye axis length, cornea curvature, white-to-white and the like is realized by one measurement. Has the advantages of cost, speed, precision, multifunction and the like.

Example two

As shown in fig. 8, the ophthalmic optical biometric system disclosed in the second embodiment of the present invention is different from the first embodiment in that: this embodiment eliminates the anterior ocular segment slit light source 1809 and the angular beam splitter 1807. In this embodiment, the light emitted from the OCT light source 1101 is output through the fiber coupler 1103 and the polarization controller 1105, and then through the fiber collimator 1107. The light beam passes through the OCT field mirror 1301 of the posterior segment and the OCT insertion mirror 1501 of the anterior segment, is reflected by the pre-spectroscope 1303, passes through the objective lens 1305 of the eye, and finally is converged to the anterior segment of the human eye to be tested after being scanned by the light path scanning device 1109. Due to the one-dimensional scanning of the optical path scanning device 1109, a slit light is formed to be incident to the human eye to be measured. The anterior ocular segment slit light formed by the light source (OCT light source 1101) in this anterior ocular segment OCT imaging system passes through the cornea, is scattered by the cornea, passes through the anterior ocular segment slit imaging lens 1801, and is finally photographed by the anterior ocular segment slit imaging device 1803, thereby forming an anterior ocular segment slit image, as shown in fig. 9.

Because the length of the eye axis of the human eye is often longer than the detection depth of the OCT system, when the OCT system is switched from anterior segment OCT to posterior segment OCT, the optical path length of a sample arm or a reference arm of the OCT system is often required to be adjusted in a matching way, so that the coherence length of OCT detection light incident on the anterior segment of the human eye and the reference arm is satisfied, or the coherence length of OCT detection light incident on the posterior segment of the human eye and the reference arm is satisfied. Therefore, the OCT system often needs to switch to change the optical path length, and in example one, the optical fiber collimator 1107 is connected to the sample arm optical fiber, and the whole optical fiber collimator is driven by the motor and can translate along the optical axis of the optical fiber collimator, so as to change the optical path length of the sample arm optical path. However, the motion mode for changing the optical path length has a relatively slow switching speed because the travel (the length of the eye axis of the human eye) is relatively long and the different eye axis lengths of the human eye need to be matched. However, in the first embodiment, the measurement of the axial length of the eye is realized by combining the imaging of the anterior segment fissure and the simultaneous detection of the posterior segment OCT, so that the influence of eye movement is avoided. In the second embodiment, to save the cost of the device, the anterior ocular segment slit light source module uses the OCT light source module 1101 and the optical path scanning device 1109 to generate slit light to provide a slit illumination light source. At this time, when the axial length of the eye is measured, it is necessary to realize switching between the optical path unit for OCT imaging adjustment of the posterior segment of the eye and the optical path unit for OCT imaging adjustment of the anterior segment of the eye by insertion or withdrawal of the OCT insertion mirror 1501 of the anterior segment of the eye; but the detection of the eye axial length is realized by combining the anterior segment fracture imaging with the posterior segment OCT imaging, and only the light source of the anterior segment fracture imaging is changed into the OCT light source 1101. Therefore, in the second embodiment, there is a short switching time when the eye axial length is measured, i.e., the insertion of the anterior ocular segment OCT insertion mirror 1501. However, since the insertion of the anterior ocular segment OCT insertion mirror 1501 requires only final positioning and does not require different length distances for different human eye axial lengths as in the optical path adjustment device, the switching speed can be increased to be fast, for example, switching by using an electromagnet.

In this embodiment, the anterior segment fracture light source 1809 and the angular beam splitter 1807 are not required to be added, and only the original OCT light source module 1101 and the optical path scanning device 1109 are required to generate anterior segment fracture illumination light, and the illumination light passes through the anterior segment OCT imaging adjustment optical path unit and then is focused on the anterior segment of the human eye to be measured. In comparison with the first embodiment, although the number of components such as the light source is reduced, the Optical Coherence Tomography (OCT) needs to be inserted into the anterior segment OCT insertion mirror 1501 when switching from posterior segment OCT to anterior segment fracture imaging, and thus a small switching time is required. In addition, a small scanning time is required to form the slit light by one-dimensional scanning of the optical path scanning device 1109. However, since the translational optical path adjusting device is not required, the time is faster than that of the scheme in the prior art (for example, the time required for the OCT switching process of the anterior and posterior segments of the eye in the prior patent document 202011120798.5 includes the time for changing the optical path translation for the optical path adjusting device when measuring the anterior and posterior segments of the eye E), and the influence of the eye movement when measuring the axial length of the eye is easier to be avoided.

Compared with the first embodiment, the second embodiment does not need to additionally debug one path of light path (the front eye joint crack illumination light path), so that the system debugging difficulty can be reduced and the system debugging speed can be improved.

In the second embodiment, the OCT light source 1101 is combined with the optical path of the optical path scanning device 1109 to realize the function of the anterior ocular segment fissure light source, without increasing the hardware cost.

In this embodiment, except for the anterior ocular segment fissure imaging module, it is understood that the fixation optical module in this embodiment is not provided with the angular beam splitter 1807, as shown in fig. 10, and other structures and principles are the same except that they are not described herein.

Example III

As shown in fig. 11, in comparison with the second embodiment, in the ophthalmic optical biometric system according to the third embodiment of the present invention, the OCT light source 1101 is not used as the anterior ocular segment slit light source, but the wavelength division multiplexer 3807 is used to couple the probe light input from the optical fiber coupler 1103 to the OCT sample arm and the light output from the anterior ocular segment slit light source 3809 into the optical fiber 1106, and then the probe light is emitted through the optical fiber head (not shown) of the sample arm. In this embodiment, the anterior ocular segment slit light source module adopts the anterior ocular segment slit light source 3809, the wavelength division multiplexer 3807, the optical fiber 1106 and the optical path scanning device 1109 to generate slit light, the light output by the anterior ocular segment slit light source 3809 is coupled by the wavelength division multiplexer 3807 and then transmitted to the optical fiber 1106, and the light output by the optical fiber 1106 is sent out slit light after one-dimensional scanning by the optical path scanning device 1109 and is focused on the anterior ocular segment of the human being to be tested after passing through the anterior ocular segment OCT imaging adjustment optical path unit.

The optical fiber 1106 is not limited to a single mode fiber, or a multimode fiber. As shown in fig. 12, the optical fiber 1106 has a core 11061, an outer layer of the core 11061 is a cladding 11063, and a sheath 11065 surrounds the cladding 11063 to protect the optical fiber.

As shown in fig. 13, the optical path for OCT imaging of the posterior segment of the eye in this embodiment differs from that of the first embodiment only in that: the OCT light source 1101 emits light, and after passing through the optical fiber coupler 1103, the light is transmitted to the wavelength division multiplexer 3807 through the polarization controller 1105, and then emitted after being transmitted through the optical fiber 1106.

As shown in fig. 14, the anterior ocular segment OCT imaging optical path in the present embodiment differs from that in the first embodiment only in that: the OCT light source 1101 emits light, and after passing through the optical fiber coupler 1103, the light is transmitted to the wavelength division multiplexer 3807 through the polarization controller 1105, and then emitted after being transmitted through the optical fiber 1106.

As shown in fig. 15, in the present embodiment, compared with the anterior ocular segment fracture imaging optical path of the second embodiment, the anterior ocular segment fracture imaging optical path of the present embodiment uses the anterior ocular segment fracture light source 3809 to emit light, enters the optical fiber 1106 through the wavelength division multiplexer 3807, is transmitted through the optical fiber 1106, exits through the sample arm optical fiber head (not shown in the figure), and then is output through the optical fiber collimator 1107. The light beam passes through the OCT field mirror 1301 of the posterior segment and the OCT insertion mirror 1501 of the anterior segment, is reflected by the pre-spectroscope 1303, passes through the objective lens 1305 of the eye, and finally is converged to the anterior segment of the human eye to be tested after being scanned by the light path scanning device 1109. Due to the one-dimensional scanning of the optical path scanning device 1109, a slit light is formed to be incident to the human eye to be measured. The light source (OCT light source 1101 and anterior segment slit light source 3809) in the anterior segment OCT imaging system forms an anterior segment slit image by passing anterior segment slit light through the cornea, scattering the light through the cornea, passing the anterior segment slit imaging lens 1801, and finally capturing the light by the anterior segment slit imaging device 1803.

When the ophthalmic optical biological measurement system of the embodiment is used for measuring the axial length of an eye, the short switching scanning time is required as in the second embodiment, and the translational optical path adjusting device is not required, so that the switching scanning time is short. The wavelength division multiplexer 3807 is used to couple the probe light input from the fiber coupler 1103 to the OCT sample arm and the light output from the anterior segment fracture light source 3809 into the optical fiber 1106. Compared with the second embodiment, the anterior segment slit light source 3809 can be made to adopt light sources with different wave bands. Since the OCT light source 1101 generally employs near-infrared light, the scattering coefficient of the near-infrared light of the anterior ocular segment tissue is small. In this embodiment, the anterior segment fracture light source 3809 may use a short wave band to increase the scattering coefficient of anterior segment tissue, such as blue light band, so as to improve the anterior segment fracture imaging effect.

Compared with the first embodiment, the embodiment does not need to additionally debug one path of light path (the anterior ocular segment crack illumination light path), so that the system debugging difficulty can be reduced and the system debugging speed can be improved.

Example IV

As shown in fig. 16, in comparison with the third embodiment, in the ophthalmic optical biometric system according to the fourth embodiment of the present invention, the probe light input into the OCT sample arm from the optical fiber coupler 1103 and the light output from the anterior segment fracture light source 4809 enter the parallel optical fiber 2106, and then exit through the optical fiber head (not shown) of the sample arm. In this embodiment, the anterior ocular segment slit light source module uses the anterior ocular segment slit light source 4809, the parallel optical fiber 2106 and the optical path scanning device 1109 to generate slit light, the light output by the anterior ocular segment slit light source 3809 passes through the parallel optical fiber 2106, and the light output by the parallel optical fiber 2106 emits slit light after one-dimensional scanning by the optical path scanning device 1109 and passes through the anterior ocular segment OCT imaging adjustment optical path unit to be focused on the anterior ocular segment of the human being to be measured.

As shown in fig. 17, the parallel optical fiber 2106 has an OCT optical path core 21061 and an anterior ocular segment slit illumination optical path core 21062, wherein the OCT optical path core 21061 is for transmitting probe light inputted into the OCT sample arm from the optical fiber coupler 1103, and the OCT optical path core 21061 is wrapped by an OCT optical path cladding 21063; the anterior ocular segment crack illumination optical path fiber core 21062 is used for transmitting light output by the anterior ocular segment crack light source 4809, and the anterior ocular segment crack illumination optical path fiber core 21062 is wrapped by the anterior ocular segment crack illumination optical fiber cladding 21064; wherein the OCT optical path cladding 21063 is arranged in parallel with the anterior ocular segment fracture illumination fiber cladding 21064 and is surrounded by a sheath 21065. The parallel optical fibers 2106 share one optical fiber head (not shown), and the probe light input from the optical fiber coupler 1103 to the OCT sample arm and the light output from the transmission anterior ocular segment slit light source 4809 are output by the optical fiber head and then enter the OCT sample arm module optical path. The shared optical fiber head forms two luminous light sources, and the distance between the two light sources is the distance d between the OCT optical path fiber core 21061 and the anterior ocular segment fracture illumination optical path fiber core 21062. The smaller the distance d, the better, d hours, the parallel optical fibers 2106 share one sample arm optical fiber head which can be close to one luminous point to emit light, and when the light passes through the OCT sample arm module 130 optical path and enters the human eye to be detected, the interval between the two detection points is smaller.

Compared with the conventional dual-core optical fiber 3106 (shown in fig. 18), the dual-core optical fiber adopts the steps that the fiber cores 31061/31062 are respectively wrapped by the fiber cladding 31063/31064, then are wrapped by the jackets 31065/31066, and then are wrapped by the large jacket 31069. At this time, the distance d3 between the two optical fiber cores tends to be large. At this time, the two fiber cores 31061/31062 emit light, which cannot be approximated to the same light emitting point, and after passing through the optical path of the OCT sample arm module 130, the interval between the two detection points will be larger when the light enters the eye to be detected.

Therefore, the optical path for OCT imaging of the posterior segment and the optical path for OCT imaging of the anterior segment are similar to those of the first or second embodiments, and the difference is that: probe light input to the OCT sample arm from the fiber coupler 1103 enters the OCT optical path core 21061 in the parallel fiber 2106 and exits through the sample arm fiber head (not shown).

As shown in fig. 19, in the anterior ocular segment crack imaging optical path of the present embodiment, compared with the second embodiment, the anterior ocular segment crack light source 4809 in the present embodiment emits light into the parallel optical fiber 2106, and the light is transmitted through the anterior ocular segment crack illumination optical path core 21062, emitted through the common optical fiber head (not shown), and then output through the optical fiber collimator 1107. The light beam passes through the OCT field lens 1301 of the posterior segment and the OCT insertion lens 1501 of the anterior segment, is reflected by the front spectroscope 1303, passes through the objective lens 1305 of the eye, and finally is converged to the anterior segment of the human eye to be detected after being scanned by the light path scanning device 1109. Due to the one-dimensional scanning of the optical path scanning device 1109, a slit light is formed to be incident to the human eye to be measured. The anterior ocular segment slit light formed by the light source (OCT light source 1101) and anterior ocular segment slit light source 4809 in the anterior ocular segment OCT imaging system passes through the cornea, is scattered by the cornea, passes through the anterior ocular segment slit imaging lens 1801, and is finally photographed by the anterior ocular segment slit imaging device 1803, thereby forming an anterior ocular segment slit image.

When the ophthalmic optical biological measurement system of the embodiment is used for measuring the axial length of an eye, the short switching scanning time is required as in the second embodiment or the third embodiment, and the translational optical path adjusting device is not required, so that the switching scanning time is short. The probe light input from the fiber coupler 1103 to the OCT sample arm and the light output from the anterior ocular segment slit light source 4809 are also input to the parallel fiber 2106. Compared with the second embodiment, the anterior segment slit light source 4809 can be a light source with different wavelength bands. Since the OCT light source 1101 generally employs near-infrared light, the scattering coefficient of the near-infrared light of the anterior ocular segment tissue is small. In the third embodiment or the fourth embodiment, the anterior segment slit light source 3809 or the anterior segment slit light source 4809 may use a short wave band to increase the scattering coefficient of anterior segment tissue, such as a blue wave band, so as to improve the anterior segment slit imaging effect.

Compared with the embodiment 1, the embodiment two, the embodiment three and the embodiment four do not need to additionally debug a path of light path (anterior ocular segment crack illumination light path), so that the system debugging difficulty can be reduced and the system debugging speed can be improved.

In the fourth embodiment, compared with the third embodiment, the wavelength division multiplexer 3807 is not required, but the parallel optical fiber 2106 is not a conventional optical fiber and is specially manufactured.

In the third embodiment and the fourth embodiment, the probe light of the OCT sample arm and the anterior segment fracture are optically coupled or output in parallel, and then enter the optical path scanning device 1109 and the optical path of the anterior segment OCT imaging adjustment optical path unit together, so that the two optical paths are basically parallel, and the scheme greatly reduces the debugging difficulty of the two optical paths.

The invention relates to an ophthalmic optical biological measurement system: on one hand, the method can realize the measurement of different depths of an object, improves the detection range (front and rear section imaging) of an OCT system, ensures stable switching system and accurate positioning, and does not influence the signal to noise ratio of the system; on the other hand, the optical beams can be focused at different positions respectively, high-quality OCT imaging of different positions can be realized for eyes with different eyesight, and the optical imaging device has higher transverse resolution. The anterior-posterior segment imaging OCT system can obtain numerous parameter data of the human eye, such as corneal curvature, corneal thickness, anterior chamber depth, lens thickness, lens surface curvature, white-to-white distance, pupil diameter, etc. The automatic detection of the instrument can be assisted by combining the anterior ocular segment photographing and automatic identification technology. By the iris recognition technology, the automatic recognition technology of the front section OCT image, the automatic recognition technology of the rear section OCT image and the like, the full-automatic detection of the system is realized. And (3) performing anterior ocular segment fracture imaging while acquiring OCT images of posterior ocular segments, so as to obtain accurate axial length data of the eye. The ophthalmic optical biological measurement system and the method for measuring the eye axis length provided by the invention have the following characteristics:

(a) The probe optical path is required to realize OCT imaging of different parts of human eyes to be measured, but the focusing positions adopted by the probe optical path are different, so the optical path adopted by measurement is different. OCT imaging of the posterior segment of the eye requires that the OCT beam be incident in parallel to the human eye (for the emmetropic eye); while OCT imaging of the anterior segment of the eye requires that the OCT beam be focused on the anterior segment of the human eye. The design is beneficial to improving OCT imaging quality of front and back sections.

(b) The aplanatic plane is positioned on the retina of the human eye to be detected during OCT imaging of the posterior segment of the eye, and the aplanatic plane is positioned on the anterior segment of the human eye to be detected during OCT imaging of the anterior segment of the eye, so that OCT imaging of different parts is realized without adjusting the optical path of a reference arm.

(c) The refraction compensation can be carried out for eyes with different vision, so that the imaging of eyes with different positions is realized.

(d) Can realize the vision fixation light path of the eyes so as to meet the vision fixation of the left eye and the right eye.

(e) The anterior segment photographing optical path and the iris automatic recognition technology are combined, and the anterior segment photographing optical path can be used for commanding the movement of the probe module, so that the detection of the human eyes to be detected is realized. The obtained iris image can measure parameters such as pupil diameter, white-to-white distance and the like.

(f) The fast and accurate switching device realizes fast OCT imaging of different parts of human eyes.

(g) Based on OCT imaging of different parts of human eyes, the rapid and accurate measurement of the axial length of the eyes, the depth of the anterior chamber, the thickness of the crystalline lens and the like can be realized without moving a reference arm.

(h) The front section and the rear section are switched quickly, less movement mechanisms are provided, and the cost is low.

(i) The fixation optical path and the OCT of the posterior segment share the diopter adjusting device, so that moving parts of the fixation optical path are reduced, confocal of the fixation optical path and the OCT of the posterior segment is realized, and fixation of the tested human eye and acquisition of OCT images of the posterior segment are facilitated.

(j) Accurate positioning of the cornea is obtained by anterior segment fissure imaging.

(k) Compared with a time domain system, the frequency domain optical coherence tomography technology is adopted, so that the scanning imaging speed is high, the imaging resolution is high, but the detection depth is shallow; compared with the scanning frequency domain optical coherence tomography, the scanning speed, the resolution and the like are equivalent, the cost is much lower, but the detection depth is shallow.

(l) The scanning scheme is switched rapidly with low cost, and OCT imaging of front and back sections is realized. And the automatic detection of human eyes to be detected is realized by combining the technology of photographing the anterior segment of the eye and the automatic identification. In addition, the optical coherence tomography is used in principle, and the system is theoretically not limited to frequency domain, frequency sweep and even time domain.

The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several equivalent substitutions and obvious modifications can be made without departing from the spirit of the invention, and the same should be considered to be within the scope of the invention.

Claims

1. An optical system for measuring the axial length of an eye, comprising an OCT light source module, an OCT imaging module, an OCT sample arm module for the posterior segment of the eye and an imaging assembly for the anterior segment of the eye, wherein:

2. The optical system according to claim 1, wherein the anterior ocular segment slit imaging module comprises an anterior ocular segment slit imaging lens (1801) and an anterior ocular segment slit imaging device (1803), the slit light emitted by the anterior ocular segment slit light source module is focused on the anterior ocular segment of the human to be measured and returns an anterior ocular segment slit light signal to pass through the anterior ocular segment slit imaging lens (1801) and is received by the anterior ocular segment slit imaging device (1803), and the anterior ocular segment slit imaging device (1803) obtains an anterior ocular segment slit image according to the anterior ocular segment slit light signal.

3. The optical system according to claim 2, wherein the anterior ocular segment fracture imaging adjustment optical path module comprises an objective lens (1305), the objective lens (1305) is located on an optical path in a first direction, wherein the optical path in the first direction is perpendicular to the human eye to be measured, and the anterior ocular segment fracture imaging lens (1801) and the anterior ocular segment fracture imaging device (1803) are respectively disposed under the objective lens (1305).

4. The optical system according to claim 1, wherein the anterior ocular segment slit light source module comprises an anterior ocular segment slit light source (1809) and a front spectroscope (1303), and the anterior ocular segment slit light source (1809) emits slit light, after passing through the front spectroscope (1303), and after passing through the anterior ocular segment slit imaging adjustment light path module, the slit light source is focused on an anterior ocular segment to be measured.

5. The optical system according to claim 1, wherein the posterior segment OCT sample arm module includes an optical path scanning device (1109) and an posterior segment OCT imaging adjustment optical path unit, the posterior segment OCT imaging adjustment optical path unit and an anterior segment OCT insertion mirror (1501) form an anterior segment OCT imaging adjustment optical path unit, the anterior segment fracture imaging adjustment optical path module employs the anterior segment OCT imaging adjustment optical path unit, the anterior segment fracture light source module employs the OCT light source module and the optical path scanning device (1109) to generate fracture light, wherein the measurement light provided by the OCT light source module emits fracture light after one-dimensional scanning by the optical path scanning device (1109) and is focused on an anterior segment of a human eye to be measured after passing through the anterior segment imaging adjustment optical path unit.

6. The optical system according to claim 1, wherein the posterior segment OCT sample arm module includes an optical path scanning device (1109) and an posterior segment OCT imaging adjustment optical path unit, the posterior segment OCT imaging adjustment optical path unit and an anterior segment OCT insertion mirror (1501) form an anterior segment OCT imaging adjustment optical path unit, the anterior segment fracture imaging adjustment optical path module employs the anterior segment OCT imaging adjustment optical path unit, the anterior segment fracture light source module employs an anterior segment fracture light source (3809), a wavelength division multiplexer (3807), an optical fiber (1106) and the optical path scanning device (1109) to generate a fracture light, light output by the anterior segment fracture light source (3809) is coupled by the wavelength division multiplexer (3807) and then transmitted into the optical fiber (1106), and a light beam output by the optical fiber (1106) is emitted after one-dimensional scanning by the optical path scanning device (1109) and focused on a anterior segment of a human to be tested after passing through the anterior segment OCT imaging adjustment unit.

7. The optical system according to claim 1, wherein the posterior segment OCT sample arm module includes an optical path scanning device (1109) and an posterior segment OCT imaging adjustment optical path unit, the posterior segment OCT imaging adjustment optical path unit and an anterior segment OCT insertion mirror (1501) form an anterior segment OCT imaging adjustment optical path unit, the anterior segment fracture imaging adjustment optical path module employs the anterior segment OCT imaging adjustment optical path unit, the anterior segment fracture light source module employs an anterior segment fracture light source (4809), a parallel optical fiber (2106) and the optical path scanning device (1109) to generate fracture light, the light output by the anterior segment fracture light source (3809) passes through the parallel optical fiber (2106), and the light output by the parallel optical fiber (2106) emits fracture light after one-dimensional scanning by the optical path scanning device (1109) and passes through the anterior segment OCT imaging adjustment optical path unit to be focused on an anterior segment of a human to be measured.

8. The optical system according to any one of claims 5 to 7, wherein the posterior segment OCT imaging adjustment optical path unit includes a posterior segment OCT field lens (1301), a pre-beam splitter (1303), and an objective lens (1305); measuring light provided by the OCT light source module passes through an OCT field lens (1301) of a posterior segment after being reflected by the light path scanning device (1109), then is reflected to the objective lens (1305) by the front dichroic mirror (1303), and is converged on the fundus of the eye to be tested by the eye to return an optical back segment signal to be transmitted to the OCT imaging module, and the OCT imaging module acquires an OCT image of the posterior segment according to the optical back segment signal;

9. The optical system according to claim 1, wherein the first optical path data is an optical path hRetinal of a retinal signal in an eye posterior segment OCT image measured from the eye posterior segment OCT image of the human eye to be measured, and the second optical path data is an optical path hCornea from an apex of an eye anterior segment slit image measured from an eye anterior segment slit image of the human eye to be measured to a corneal vertex of the human eye to be measured;

10. A method of measuring the axial length of a human eye to be measured using the optical system of any one of claims 1 to 9, comprising the steps of:

11. The method of claim 10, wherein the eye axis length Leye of the human eye under test is calculated using the formula:

Leye＝△L+X-hCornea+hRetinal；