Ophthalmologic measuring system
Technical Field
The invention belongs to the field of ophthalmic examination equipment, and particularly relates to an ophthalmic measurement system.
Background
Effective prevention and treatment of cataract surgery, corneal refractive surgery, and juvenile myopia requires accurate measurement of a number of parameters of the eye, such as anterior and posterior corneal surface curvature, corneal thickness, anterior chamber depth, lens thickness, anterior and posterior lens surface curvature, axial length of the eye, white-to-white distance, pupil diameter, and the like. In the prior art, the most widely used ultrasonic technology is used for obtaining the plurality of parameters, but the measurement precision is low.
In response to the disadvantages of the ultrasonic technology, an ophthalmic measuring system based on OCT (Optical Coherence Tomography) technology has been developed for obtaining the plurality of parameters. OCT is a new optical imaging technology, has the advantages of high resolution, high imaging speed, no radiation damage, compact structure and the like, and is an important potential tool for basic medical research and clinical diagnosis application. OCT techniques can be divided into TDOCT (Time Domain OCT) and FDOCT (Frequency Domain OCT), which can be further divided into ssct (Swept Source OCT) and SDOCT (Spectral Domain OCT). The ophthalmologic measurement system is easy to realize based on a time domain OCT technology or a swept source OCT technology, and the realization difficulty is high based on a spectral domain OCT technology.
Chinese patent application No. 200710020707.9 discloses a method for measuring the axial length of the eye, which is the length from the corneal vertex to the fovea of the macula of the retina, using time-domain OCT. The method adopts a stepping motor to move a probe back and forth to realize the adjustment of an optical path so as to image the cornea and the eyeground, and has the following defects: 1) the imaging time required by the forward and backward movement of the stepping motor is long, real-time imaging cannot be realized, and the measured object can shake, blink and the like during imaging, so that the measured parameters such as the eye axis length and the like have large errors; 2) the method cannot perform transverse scanning on the eyes and cannot judge the positions of the corneal vertex and the macular fovea, so that the difference between the measured axial length of the eyes and the actual axial length of the eyes is large; 3) organs such as cornea, aqueous humor and crystalline lens exist between the cornea and the retina to refract light entering the eye, and the method cannot realize the focusing of measuring light on the cornea and the retina at the same time, and has poor imaging quality.
In short, the ophthalmological measurement system based on the time-domain OCT has the disadvantages of slow imaging speed, low measurement accuracy, poor image quality, and the like, and the defects of the ultrasonic technology are not overcome. The ophthalmology measuring system based on the swept source OCT technology overcomes many defects of the ultrasonic technology, but is high in price and difficult to popularize.
Chinese patent publication No. CN103892791A discloses a system and method for switching the scanning of anterior segment and posterior segment of eye to be detected so as to determine the axial length of eye based on spectral domain OCT technique. However, the switching mechanism adopts a plurality of switching mechanisms, and the switching of the scanning of the anterior segment and the posterior segment of the eye to be detected can be realized only by matching the switching mechanisms, so that the structure is complex and the maintenance is difficult; the cost is high and the popularization is difficult.
Disclosure of Invention
Based on OCT technology, the invention provides an ophthalmologic measurement system, belongs to another technical scheme which can realize the switching of the scanning of the anterior segment and the posterior segment of the eye to be detected so as to determine the axial length of the eye to be detected based on spectral domain OCT technology, and can overcome the defects of complex structure and high cost in the prior art.
The technical scheme provided by the embodiment of the invention is as follows:
an ophthalmologic measurement system for detecting an eye to be examined comprises a main body module, a reference plane, a switching scanning element, an anterior segment optical path component, a posterior segment optical path component, a light splitting element and a system main optical axis, wherein the main body module is used for providing measurement light and reference light, receiving first anterior segment signal light and second posterior segment signal light, respectively interfering the first anterior segment signal light and the second posterior segment signal light with the reference light and collecting corresponding interference light; the system main optical axis comprises an emergent main optical axis which is positioned on the reference plane, the switching scanning element can rotate around a fixed axis, and the switching scanning element has a first working position and a second working position and can be switched between the first working position and the second working position by rotating around the fixed axis; the anterior ocular segment optical path assembly comprises a first reflector, the posterior ocular segment optical path assembly comprises a reflecting element and an optical element, and the intersection point of the main optical axis of the system and the first reflector and the intersection point of the main optical axis of the system and the optical element are both positioned on the reference plane; when the switching scanning element is in the first working position, the measurement light provided by the main body module is reflected by the switching scanning element to the first reflecting mirror, reflected by the first reflecting mirror to the light splitting element, transmitted to the eye to be inspected through the light splitting element, and scattered by the anterior segment of the eye to be inspected to form anterior segment signal light, the anterior segment signal light is scattered to the light splitting element through the anterior segment of the eye to be inspected, the light splitting element splits the anterior segment signal light into the first anterior segment signal light and the second anterior segment signal light, transmits the first anterior segment signal light to the first reflecting mirror, is reflected to the switching scanning element through the first reflecting mirror, and is reflected by the switching scanning element to enter the main body module,
when the switching scanning element is in the second working position, the measurement light provided by the main body module is reflected to the retroreflective element by the switching scanning element, reflected to the optical element by the retroreflective element, reflected to the light splitting element by the optical element, and transmitted to the eye to be inspected by the light splitting element, and scattered by the posterior segment of the eye to be inspected to form posterior segment signal light, which is scattered to the light splitting element by the posterior segment of the eye to be inspected, the light splitting element splits the posterior ocular segment signal light into first posterior ocular segment signal light and the second posterior ocular segment signal light and transmits the second posterior ocular segment signal light to the optical element, the second eye back signal light is reflected to the retroreflective element through the optical element, then reflected to the switching scanning element through the retroreflective element and reflected to enter the main body module through the switching scanning element.
In a preferred embodiment of the present invention, the switching scanning element is rotatable around the fixed axis in the first working position to scan the anterior segment of the eye to be inspected, the switching scanning element is rotatable around the fixed axis in the second working position, and the switching scanning element is rotatable around the fixed axis in the second working position to scan the posterior segment of the eye to be inspected.
In a preferred embodiment of the present invention, the fixed axis is parallel to the main exit optical axis when the system is in the detection condition.
In a preferred embodiment of the present invention, the retroreflective element includes a first reflective surface and a second reflective surface, an intersection point of the main optical axis of the system and the second reflective surface is located on the reference plane, and when the switching scanning element is located at the second working position, the measurement light is reflected to the first reflective surface by the switching scanning element, and then is reflected to the optical element by the first reflective surface and the second reflective surface in sequence.
In a preferred embodiment of the present invention, the anterior ocular segment optical path assembly includes a second reflecting mirror, and the second reflecting surface, the optical element, the first reflecting mirror, the switching scanning element and the second reflecting mirror are sequentially arranged along a direction perpendicular to the emergent main optical axis, and when the switching scanning element is located at the first working position, the measuring light provided by the main body module is reflected to the first reflecting mirror by the switching scanning element, reflected to the second reflecting mirror by the first reflecting mirror, and reflected to the light splitting element by the second reflecting mirror.
In a preferred embodiment of the present invention, the anterior ocular segment optical path assembly includes a third reflector, a connection line between an intersection point of the system main optical axis and the first reflector and an intersection point of the system main optical axis and the second reflector is perpendicular to the emergent main optical axis, a connection line between an intersection point of the system main optical axis and the second reflector and an intersection point of the system main optical axis and the third reflector are parallel to the emergent main optical axis, and a connection line between an intersection point of the system main optical axis and the third reflector and an intersection point of the system main optical axis and the light splitting element is perpendicular to the emergent main optical axis; when the switching scanning element is located at the first working position, the measurement light provided by the main body module is reflected to the first reflecting mirror by the switching scanning element, reflected to the second reflecting mirror by the first reflecting mirror, reflected to the third reflecting mirror by the second reflecting mirror, and reflected to the light splitting element by the third reflecting mirror.
In a preferred embodiment of the present invention, the retroreflective element is movable in a direction perpendicular to the outgoing main optical axis.
In a preferred embodiment of the present invention, the switching scanning element is located outside the reference plane, and the fixed axis is parallel to the reference plane and perpendicular to the outgoing main optical axis.
In a preferred embodiment of the present invention, the retroreflective element includes a first reflective surface and a second reflective surface, a connection line between an intersection point of the system main optical axis and the switching scanning element and an intersection point of the system main optical axis and the first reflective surface is perpendicular to the reference plane, a connection line between an intersection point of the system main optical axis and the second reflective surface and an intersection point of the system main optical axis and the optical element is also perpendicular to the reference plane, and when the switching scanning element is located at the second working position, the measurement light is reflected to the first reflective surface by the switching scanning element and then sequentially reflected to the optical element by the first reflective surface and the second reflective surface.
In a preferred embodiment of the present invention, the anterior ocular segment optical assembly includes a second reflector, a line connecting an intersection point of the main optical axis of the system and the first reflector and an intersection point of the main optical axis of the system and the second reflector is parallel to the emergent main optical axis, and a line connecting an intersection point of the main optical axis of the system and the second reflector and an intersection point of the main optical axis of the system and the light splitting element is perpendicular to the emergent main optical axis; when the switching scanning element is located at the first working position, the measuring light provided by the main body module is reflected to the first reflecting mirror by the switching scanning element, reflected to the second reflecting mirror by the first reflecting mirror, and reflected to the light splitting element by the second reflecting mirror.
In a preferred embodiment of the present invention, the retroreflective element is movable in a direction perpendicular to the reference plane.
In a preferred embodiment of the present invention, the reference plane is perpendicular to a line connecting centers of pupils of left and right eyes of the eye to be inspected when the system is in the inspection condition.
In a preferred embodiment of the present invention, the system includes a scanning plane, the scanning plane is perpendicular to the reference plane, the emergent main optical axis is located in the scanning plane, when the system is in a detection operating condition, a line connecting centers of pupils of left and right eyes of the eye to be detected is located in the scanning plane, and paths of the measurement light transmitted to the eye to be detected through the light splitting element are located in the scanning plane.
The ophthalmologic measuring system provided by the embodiment of the invention controls and switches the rotation angle of the scanning element to rapidly switch the anterior segment imaging or the posterior segment imaging of the eye to be detected, and obtains the relevant parameters of the eye to be detected by calculating the optical path difference of the anterior segment imaging and the posterior segment imaging; and the switching scanning element also has a scanning function, so that the scanning of the anterior segment and the posterior segment of the eye to be detected can be realized. Compared with the prior art, the invention provides another technical scheme which can realize the switching of the scanning of the anterior segment and the posterior segment of the eye to be detected so as to determine the axial length of the eye to be detected based on the spectral domain OCT technology, and can overcome the defects of complex structure and high cost in the prior art.
Furthermore, in the ophthalmic measurement system provided by the embodiment of the present invention, the anterior ocular segment optical path component and the posterior ocular segment optical path component are both located on the reference plane, so that the optical path structure can be vertically arranged, the ophthalmic measurement system has a relatively beautiful appearance, and is in line with human engineering, thereby avoiding the oppression on the patient to be measured. On the basis, the switching scanning element can rotate around a certain shaft to realize anterior segment scanning and posterior segment scanning and switch between the anterior segment scanning and the posterior segment scanning, so that the eye to be detected can be scanned in the horizontal direction.
Drawings
Fig. 1 is a block diagram of an ophthalmic measurement system according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of the ophthalmic measurement system of fig. 1.
Fig. 3 is a schematic diagram of the operation principle of the switching scanning element in fig. 2.
Fig. 4 is a schematic structural view of a retroreflective element according to an alternative embodiment of the present invention.
Fig. 5(a) to 5(b) are timing diagrams of switching the scanning element and the detector in fig. 2.
Fig. 6 is a schematic diagram of the distribution of the illumination lamps in the illumination light source of fig. 2.
Fig. 7 is a block diagram of an ophthalmic measurement system according to a second embodiment of the present invention.
Fig. 8 is a schematic diagram of the ophthalmic measurement system of fig. 7.
Fig. 9 is a schematic diagram of the operation principle of the switching scanning element in fig. 8.
The notations in the figures are as follows:
in the first embodiment:
system main optical axis L emergent main optical axis L1Eye to be inspected E
Main body module 100
Light source 101 coupler 103 detector 105 reference arm assembly 130
Reference arm lens 131 reference arm mirror 133 polarization controller 107
Focusing lens 109 controller 111
Reference plane 10
First end 11, second end 13, third end 15, fourth end 17
Switching the scanning element 30
First working position 30a and second working position 30b are fixed on shaft 33
Anterior ocular segment optical assembly 50
First mirror 51 first relay lens 53 second mirror 55
Third mirror 57 second relay lens 59
Posterior ocular segment optical assembly 70
Retroreflective elements 71 optical elements 73 refractive adjustment elements 75
Light splitting element 80
Objective lens 90
Vision fixation optical module 300
Fixation light source 301 fixation lens 303
Anterior ocular segment imaging module 500
Illumination light source 501 lamp 501a spectroscope 502 expanding lens 503
Third mirror 505 image pickup lens 507 image pickup device 509
In the second embodiment:
system main optical axis L emergent main optical axis L1Eye to be inspected E
Body module 2100
Light source 2101 coupler 2103 detector 2105 reference arm assembly 2130
Reference arm lens 2131 reference arm mirror 2133 polarization controller 2107
Focusing lens 2109 controller 2111
Reference plane 210
First terminal 211, second terminal 213, third terminal 215, fourth terminal 217
Switching the scanning element 230
First working position 230a second working position 230b fixed axis 233
Anterior ocular segment optical assembly 250
First mirror 251, first relay lens 253, and second mirror 255
Second relay lens 259
Posterior ocular segment optical assembly 270
Retroreflective element 271 optical element 273 diopter adjustment element 275
Light splitting element 280
Objective lens 290
Vision fixation optical module 2300
Fixation light source 2301 fixation lens 2303
Anterior ocular segment imaging module 2500
Illuminating light source 2501 illuminating lamp 2501a spectroscope 2502 vision expanding lens 2503
Third mirror 2505 imaging lens 2507 imaging camera 2509
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
The present embodiment provides an ophthalmologic measurement system (hereinafter, simply referred to as "system") for detecting an eye to be inspected E to determine an axial length of the eye to be inspected E. Preferably, the system also determines a plurality of parameters of the eye E, such as corneal curvature, anterior chamber depth, white-to-white distance, pupil diameter, etc. of the eye E.
Referring to fig. 1 and 2, the system includes a main body module 100, a reference plane 10, a scanning plane (not shown), a switching scanning element 30, an anterior ocular segment optical path assembly 50, a posterior ocular segment optical path assembly 70, a light splitting element 80, and a main optical axis L of the system. Preferably, the system further comprises an ocular objective 90, a fixation optical module 300 and an anterior segment imaging module 500.
In fig. 1 and 2, the dotted line indicates the main optical axis L of the system, which includes the exit main optical axis L1Said main emergent optical axis L1Located in the reference plane and the scan plane. When the system is in a detection working condition, the main body module 100 generates reference light and provides measurement light to the switching scanning element 30, the measurement light is transmitted to the anterior segment optical path component 50 or the posterior segment optical path component 70 according to the rotation angle of the switching scanning element 30, is reflected or transmitted by the light splitting element 80, is focused to a corresponding part of the eye to be detected E through the objective lens 90, is scattered by the eye to be detected E to form signal light, the signal light propagates back to the main body module 100 in a direction opposite to the measurement light and interferes with the reference light to generate interference light, and the main body module 100 further collects the interference light. The paths of the measuring light transmitted to the eye to be inspected by the light splitting element are all located on the scanning plane.
The reference plane 10 is perpendicular to the line connecting the centers of the left and right pupils of the eye E when the system is in the detection working condition, and the baseThe quasi-plane 10 includes a first end 11, a second end 13 opposite to and parallel to the first end 11, a third end 15 perpendicular to the first end 11, and a fourth end 17 opposite to and parallel to the third end 15, wherein the first end 11, the second end 13, the third end 15, and the fourth end 17 are connected end to form a closed rectangle. The first end 11 and the second end 13 are perpendicular to the emergent main optical axis L1The third end 15 and the fourth end 17 are parallel to the emergent main optical axis L1。
It is understood that the reference plane 10 is a virtual plane for describing the positional relationship between the components in the system.
The scanning plane is perpendicular to the reference plane 10, and when the system is in a detection working condition, a connecting line of the centers of the left and right eye pupils of the eye E to be detected is located on the scanning plane. The scan plane is perpendicular to the reference plane. The reference plane is perpendicular to the connecting line of the centers of the left and right eye pupils of the eye E to be detected. It is understood that the scan plane is also a virtual plane for describing the position relationship between the components in the system.
As shown in fig. 2, in the present embodiment, the main body module 100 includes a light source 101, a coupler 103, a reference arm assembly 130, a detector 105, a polarization controller 107, a focusing lens 109, and a controller 111. The reference arm assembly 130 further includes a reference arm lens 131 and a reference arm mirror 133. The light source 101 may be an OCT light source, which emits weak coherent light with a wavelength of near infrared and transmits the light to the coupler 103, and the coupler 103 splits the received light into two beams, wherein one beam is focused by the reference arm lens 131 and reflected by the reference arm mirror 133 and then returns to the coupler 103 as reference light. The other beam is focused by the polarization controller 107 and the focusing lens 109 in sequence and then transmitted to the switching scanning element 30 as the measurement light.
Referring to fig. 3, the dashed line in fig. 3 indicates the main optical axis L of the system. In this embodiment, the switching scanning element 30 is disposed near the second end 13, and the switching scanning element 30 is specifically a galvanometer. The switching scanning element 30 can rotate around a fixed axis 33In this embodiment, the fixed axis 33 is parallel to the reference plane 10 and the main emission optical axis L1I.e. the fixed axis 33 is parallel to the second end 15, it will be understood by those skilled in the art that in other embodiments of the present invention, the fixed axis may be arranged perpendicular to the reference plane, the switching scanning element 30 has a first working position 30a and a second working position 30b and is switchable between the first working position 30a and the second working position 30b by rotating around the fixed axis 33, the propagation direction of the measuring light may be selected by controlling the switching scanning element 30 to be at different rotation angles, so that the measuring light is transmitted to the anterior eye segment optical path assembly 50 or the posterior eye segment optical path assembly 70, specifically, the switching scanning element 30 may be controlled to switch between the first working position 30a and the second working position 30b, when the switching scanning element 30 is at the first working position 30a, as shown in fig. 3, the angle between the propagation path of the incident light at the switching scanning element 30 and the propagation path of the reflected light is β, the measuring light is transmitted to the anterior eye segment optical path assembly 50, and when the switching scanning element 30 is at the second working position 30b, the angle between the propagation path of the reflected light at the switching scanning element 30b and the propagation path of the reflected light is α, as shown in fig. 3.
Specifically, in this embodiment, the system further includes an electronic control component (e.g., a motor), the electronic control component has an electrically controlled rotating bracket (e.g., a rotating shaft), the electronic control component is electrically connected to the controller 111, the switching scanning element 30 is fixed on the electrically controlled rotating bracket, the controller 111 controls the rotation of the electronic control component to drive the rotation of the electrically controlled rotating bracket, so as to control the rotation angle of the switching scanning element 30, when the switching scanning element 30 rotates to the first working position 30a, the switching scanning element reflects the measurement light to the anterior ocular segment optical path component 50, and when the switching scanning element 30 rotates to the second working position, the switching scanning element reflects the measurement light to the posterior ocular segment optical path component 70.
It is understood that in other embodiments of the present invention, the system may also control the rotation angle of the switching scanning element 30 through manual adjustment, and specifically, the system includes a rotating bracket for fixing the switching scanning element 30, the rotating bracket provides a knob, and the rotation angle of the switching scanning element 30 is adjusted through manual rotation of the knob to inject the measuring light into the corresponding position of the eye to be inspected E.
It is understood that in other embodiments of the present invention, the switching scanning element 30 can also be controlled to rotate angularly by other mechanical devices or electrical methods, and the design solution satisfying this requirement is within the scope of the present invention, and will not be described herein again.
Referring to fig. 2 again, in this embodiment, the measurement light reaches the light splitting element 80 after passing through the anterior ocular segment optical path assembly 50 or the posterior ocular segment optical path assembly 70, and the light splitting element 80 is specifically a half-transmitting and half-reflecting mirror, and can transmit the measurement light transmitted by the anterior ocular segment optical path assembly 50 and reflect the measurement light transmitted by the posterior ocular segment optical path assembly 70. It is understood that light impinging on the half mirror is partially reflected by the half mirror and partially transmitted by the half mirror. For example, 30% of the light is reflected and 70% is transmitted; as another example, 50% of the light is reflected and 50% is transmitted; as another example 70% of the light is reflected and 30% is transmitted.
It can be understood that, without creative work, a person skilled in the art may modify the system, and in the modified technical solution, the half-mirror serving as the light splitting element may reflect the measurement light transmitted by the anterior ocular segment optical path component and transmit the measurement light transmitted by the posterior ocular segment optical path component.
Specifically, in the present embodiment, when the switching scanning element 30 is in the first operating position 30a, the measurement light passes through the spectroscopic element 80 and is focused to the anterior segment of the eye E to be inspected, such as the cornea of the eye E to be inspected, via the objective lens 90. When the switching scanning element 30 is in the second operating position 30b, the measuring light is reflected by the spectroscopic element 80 and focused to a posterior segment of the eye E to be inspected, such as a retina of the eye E to be inspected, via the objective lens 90.
In this embodiment, the anterior ocular segment optical assembly 50 includes at least two total reflection mirrors, i.e., a first mirror 51 and a second mirror 55. When the switching scanning element 30 is in the first working position 30a, the light transmitted by the switching scanning element 30 is reflected to the light splitting element 80 by the first reflecting mirror 51 and the second reflecting mirror 55 in sequence.
Preferably, the anterior ocular segment optical assembly 50 includes three total reflection mirrors, namely a first mirror 51, a second mirror 55, and a third mirror 57. The first mirror 51 is closer to the third end 15 than the switching scanning element 30, the second mirror 55 is closer to the fourth end 17 than the first mirror 51, and the third mirror 57 is closer to the first end 11 than the second mirror 55. The intersection point of the system main optical axis L and the first reflecting mirror 51, the intersection point of the system main optical axis L and the second reflecting mirror 55, and the intersection point of the system main optical axis L and the third reflecting mirror 57 are all located on the reference plane 10. The system principal optical axis L with the point of intersection of first speculum 51 and the system principal optical axis L with the line of intersection of second speculum 55 is on a parallel with first end 11, the system principal optical axis L with the point of intersection of second speculum 55 with the line of intersection of system principal optical axis L with the third speculum 57 is on a parallel with third end 15, the system principal optical axis L with the point of intersection of third speculum 57 with the line of intersection of system principal optical axis L with beam splitting component 80 is on a parallel with first end 11. When the switching scanning element 30 is located at the first working position 30a, the light transmitted by the switching scanning element 30 is reflected to the light splitting element 80 by the first reflecting mirror 51, the second reflecting mirror 55 and the third reflecting mirror 57 in sequence.
It should be noted that, in this embodiment, the anterior ocular segment optical path assembly 50 further includes at least one relay lens, wherein there is at least one relay lens between the first reflector 51 and the second reflector 55, and when the switching scanning element 30 rotates to the first working position 30a, the first reflector 51 reflects the measuring light to the second reflector 55 through the relay lens; or at least one relay lens between the second reflecting mirror 55 and the light splitting element 80, in which case the measuring light is reflected by the second reflecting mirror 55 and is transmitted through the relay lens to the light splitting element 80.
Preferably, in this embodiment, the anterior ocular segment optical assembly 50 includes two relay lenses, namely a first relay lens 53 and a second relay lens 59, wherein the first relay lens 53 is between the first reflector 51 and the second reflector 55, and the second relay lens 59 is between the third reflector 57 and the light splitting element 80. The geometric center of the first relay lens 53 and the geometric center of the second relay lens 59 are both located on the reference plane 10, the geometric center of the first mirror 51, the geometric center of the second mirror 55, and the geometric center of the first relay lens 53 are located on the same straight line, and a line connecting the geometric center of the third mirror 57 and the geometric center of the second relay lens 59 is parallel to the first end 11. At this time, when the switching scanning element 30 is located at the first working position 30a, the measuring light reflected by the switching scanning element 30 is reflected by the first reflecting mirror 51, transmitted by the first relay lens 53, reflected by the second reflecting mirror 55 and the third reflecting mirror 57 in sequence, transmitted by the second relay lens 59, and irradiated to the light splitting element 80.
As shown in fig. 2, in the present embodiment, when the switching scanning element 30 is in the first working position 30a, the beam splitter 80 receives the measurement light from the anterior ocular segment optical path assembly 50, and the measurement light passes through the beam splitter 80 and is focused to the anterior ocular segment of the eye E to be inspected, such as the cornea of the eye E to be inspected, through the objective lens 90. The anterior segment scatters the measurement light to generate anterior segment signal light, which is irradiated to the light splitting element 80 through the ocular objective lens 90. The signal light of the anterior ocular segment is divided into a first signal light of the anterior ocular segment and a second signal light of the anterior ocular segment by the light splitting element 80, and the second signal light of the anterior ocular segment is reflected by the light splitting element 80 to enter the optical path component 70 of the posterior ocular segment and is not transmitted back to the main body module 100; the first anterior ocular segment signal light is transmitted back to the main body module 100 through the light splitting element 80, the anterior ocular segment optical path component 50, and the switching scanning element 30 in sequence along a direction opposite to the measurement light, and interferes with the reference light in the coupler 103 to generate interference light, and the detector 105 receives and processes the interference light and transmits the interference light to the controller 111. Since the polarization direction of the first eye front section signal light is controlled by the polarization controller 107 before returning to the coupler 103, the effect of interference is ensured.
In this embodiment, the posterior ocular segment optical path assembly 70 includes a reflective element 71 and an optical element 73, and when the switching scanning element 30 is in the second working position 30b, the measurement light provided by the switching scanning element 30 is reflected by the reflective element 71 and the optical element 73 in sequence and then transmitted to the beam splitter 80.
Specifically, the optical element 73 may be a total reflection mirror, a half-transmission mirror, or a dichroic mirror, and an intersection point of the main optical axis L of the system and the optical element 73 is located on the reference plane 10.
The retroreflective element 71 includes a first reflective surface and a second reflective surface. Referring to fig. 3 again, the retroreflective element 71 may be an angular prism, and preferably, the retroreflective element 71 is a right-angle prism. The right-angle prism includes a first reflecting surface 71a and a second reflecting surface 71b, preferably, an included angle between the first reflecting surface 71a and the second reflecting surface 71b is set to be a right angle, and in other embodiments of the present invention, the included angle between the first reflecting surface 71a and the second reflecting surface 71b may also be set to be an acute angle or an obtuse angle. An intersection point of the system main optical axis L and the second reflection surface 71b is located on the reference plane 10, and a connection line between the intersection point of the system main optical axis L and the second reflection surface 71b and the intersection point of the system main optical axis L and the first reflection surface 71a is perpendicular to the reference plane 10. When the switching scanning element 30 is located at the second working position 30b, the measuring light provided by the switching scanning element 30 is reflected by the first reflecting surface 71a, the second reflecting surface 71b and the optical element 73 in sequence and then transmitted to the light splitting element 80.
Referring to fig. 4, in another embodiment, the retroreflective element 71 may also be a mirror group including a first mirror 71c and a second mirror 71d, a reflective surface of the first mirror 71c is a first reflective surface, and a reflective surface of the second mirror 71d is a second reflective surface, preferably, the reflective surface of the first mirror 71c and the reflective surface of the second mirror 71d are set to be a right angle, and in another embodiment of the invention, the reflective surface of the first mirror 71c and the reflective surface of the second mirror 71d may also be set to be an acute angle or an obtuse angle. The intersection point of the system main optical axis L and the second reflecting mirror 71d is located on the reference plane 10, and a connection line between the intersection point of the system main optical axis L and the second reflecting mirror 71d and the intersection point of the system main optical axis L and the first reflecting mirror 71c is perpendicular to the reference plane 10. When the switching scanning element 30 is located at the second working position 30b, the measuring light provided by the switching scanning element 30 is reflected by the first reflecting mirror 71c, the second reflecting mirror 71d and the optical element 73 in sequence and then transmitted to the light splitting element 80.
Preferably, the optical path assembly 70 further comprises a displacement control element (not shown), and the retroreflective element 71 can be used to adjust the optical path. The retroreflective element 71 is fixed to the displacement control element and is movable with the displacement control element in a direction parallel to the first end 11, thereby changing the optical path length that the measurement light experiences in the posterior ocular segment optical assembly 70. The posterior segment optical path assembly 70 further includes a dioptric adjustment unit 75, the dioptric adjustment unit 75 is disposed between the optical element 73 and the light-splitting element 80, and the dioptric adjustment unit 75 is movable between the optical element 73 and the light-splitting element 80, so that the measurement light can be focused on the posterior segment of the eye E, for example, the retina of the eye E, for different diopters of the eye E. During the movement, the intersection point of the system main optical axis L and the dioptric adjustment unit 75 is always located on the reference plane 10. The refraction adjusting unit 75 may be a lens.
It should be noted that, when measuring the posterior segment of the eye E, since the length of the eye axis of different eyes E is different, it is necessary to provide an optical path length adjusting unit in one of the anterior segment optical path component 50 and the posterior segment optical path component 70, and preferably, an optical path length adjusting unit, that is, the retroreflective element 71, in the posterior segment optical path component 70.
It is understood that in other embodiments of the present invention, the displacement of the retroreflective element 71 can be calculated by a stepping motor, a voice coil motor, or a grating ruler, a capacitive grating ruler, etc., and is not limited to the above-mentioned moving device or sensor, as long as the structure satisfying the design is within the protection scope of the present invention.
It is understood that in other embodiments of the present invention, the retroreflective element 71 may also be a movable retro-reflector, and the optical path adjustment can be achieved by moving the movable retro-reflector only when the optical path adjustment is performed.
In addition, in performing posterior segment measurement of the eye, the position at which the measurement light is focused in the eye E to be inspected can be adjusted by the diopter adjustment element 75, for example, by moving the diopter adjustment element 75 to focus light on the retina of the eye E to be inspected to realize measurement of the eye E to be inspected having myopia or hyperopia. In particular, the refractive adjustment member 73 is fixed to a translation device (not shown) and its movement is controlled manually or electrically to achieve refractive adjustment.
In this embodiment, after the measurement light is focused on the posterior segment of the eye E to be inspected, the posterior segment scatters the measurement light and generates a posterior segment signal light, and the posterior segment signal light is irradiated to the light splitting element 80 through the objective lens 90. The posterior ocular segment signal light is divided into a first posterior ocular segment signal light and a second posterior ocular segment signal light by the light splitting element 80, and the first posterior ocular segment signal light is transmitted by the light splitting element 80 to enter the anterior ocular segment light path assembly 50 and is not transmitted back to the main body module 100; the second eye posterior segment signal light is reflected by the light splitting element 80 and then sequentially transmitted back to the main body module 100 through the eye posterior segment light path assembly 70 and the switching scanning element 30 along the direction opposite to the measuring light, and is interfered with the reference light in the coupler 103 to generate interference light, and the detector 105 receives the interference light and transmits the interference light to the controller 111 after processing. Since the polarization direction of the second eye posterior segment signal light is controlled by the polarization controller 107 before returning to the coupler 103, the effect of interference is ensured. The controller 111 obtains a parameter corresponding to the eye E to be inspected, such as an axial length of the eye E to be inspected, from the optical path difference between the anterior segment imaging and the posterior segment imaging.
Here, the system principal optical axis L along which the measurement light can propagate from the main body module 100 to the eye E is explained, and it is understood by those skilled in the art that the system principal optical axis L passes through at least the spherical centers of two spherical surfaces of at least one lens in the system, for example, the spherical centers of two spherical surfaces of the focusing lens 109 or the spherical centers of two spherical surfaces of the ocular objective lens 90. Preferably, the system principal optical axis L passes through at least the spherical centers of two spheres of all lenses in the system, including the focusing lens 109, the first relay lens 53, the second relay lens 59, the diopter adjustment element 75, and the objective lens 90.
The main emergent optical axis L1Is part of the main optical axis L of the system, the exit main optical axis L1Is a straight line segment, and when the system is in a detection working condition, the measuring light can pass through the emergent main optical axis L1Into the eye E to be examined.
It should be noted that, in the present embodiment, the switching scanning element 30 can perform scanning imaging on the eye E to be inspected, in addition to performing rapid switching of the optical path. The switching scanning element 30 is rotatable in the first operating position 30a to scan the anterior segment of the eye E, and the switching scanning element 30 is rotatable in the second operating position 30b to scan the posterior segment of the eye E.
Referring to fig. 5(a) to 5(b), the switching scanning element 30 starts to rotate from the initial position 1, t1Working time, t, required for scanning the anterior or posterior segment of the eye E2Time required to switch the scanning element 30 from anterior segment imaging to posterior segment imaging, t3For performing the cutting after scanning the posterior segment of the eye EThe time required for the scanning element 30 to return to the initial position 1 is changed. The "anterior ocular segment position" is a position at which the switching scanning element 30 is in the first working position 30a so that the measurement light is focused on the anterior ocular segment of the eye E. The "posterior segment-scanning position" is a position where the switching scanning element 30 is in the second working position 30b so that the measurement light is focused on the posterior segment of the eye E.
When an anterior segment image is to be acquired, the switchable scanning element 30 is rotated in the first operating position 30a, while the detector 105 simultaneously starts acquiring signals. When passing t1At time, the switching scanning element 30 is in position 2. After the detector 105 collects the anterior segment image, the switching scanning element 30 is switched to the second working position 30b, and the time required for the process is t2The switching scanning element 30 reaches position 3.
Then, the acquisition of the posterior segment image is started, and the switching scanning element 30 rotates in the second working position 30b, and the detector 105 synchronously starts to acquire signals. When passing t1At time, the switching scanning element 30 is in position 4. After the detector 105 acquires the posterior segment image of the eye, the switching scanning element 30 rotates in the reverse direction to return to the initial position 1, and the time required for this process is t3The switching scanning element 30 returns to the initial position 1.
In the embodiment of the present invention, the controller 111 is used to control the timing and the state change of the scanning element 30 and the detector 105.
Referring to fig. 2 again, in the present embodiment, the system further includes a fixation optical module 300, and the fixation optical module 300 includes a fixation light source 301 and a fixation lens 303. The light emitted by the fixation light source 301 is visible light, the fixation light source 301 is specifically a display screen for displaying a fixation target for the eye E to be inspected to fix the vision, and the display screen can be an LCD screen, an OLED screen, or an LED array screen.
Preferably, in this embodiment, the optical element 73 is a dichroic mirror. Specifically, the optical element 73 can transmit light output from the fixation light source 301 and reflect light output from the light source 101.
The light emitted by the fixation light source 301 is transmitted through the fixation lens 303 and the optical element 73, is adjusted and bent by the refraction adjusting element 75, is reflected by the beam splitter 80, and is focused on the posterior segment of the eye to be inspected E, such as the retina of the eye to be inspected E, through the objective lens 90.
Specifically, in this embodiment, the fixation position of the eye to be inspected E may be changed using a fixation mark, and the fixation mark may be moved up, down, left, and right, so as to detect different positions of the eye to be inspected. The light emitted by the fixation light source 301 can adjust diopter through the diopter adjusting element 75, if the light emitted by the fixation light source 301 cannot be adjusted to be flexible, the visual fixation mark has different definition when the eye to be inspected E with different vision is observed, which makes the eye to be inspected feel uncomfortable when the eye to be inspected is fixed, therefore, preferably, the light path emitted by the fixation light source 301 is adjusted to be flexible through the diopter adjusting element 75 and focused on the fundus retina of the eye to be inspected E, so that the eye to be inspected E can see the clear visual fixation mark.
As shown in fig. 2, the system provided in this embodiment further includes an anterior segment imaging module 500, which is configured to capture an image to determine parameters such as a corneal center curvature, a pupil diameter, and a white-to-white distance of the eye E, for example, capture an iris image of the eye E. The anterior segment imaging module 500 is electrically connected to the controller 111, and includes: an illumination light source 501, a beam splitter 502, a view expanding lens 503, a third reflector 505, an image pickup lens 507, and an image pickup device 509.
Specifically, the illumination light source 501 is disposed between the objective lens 90 and the eye E, and the illumination light source 501 emits near infrared light. The dichroic mirror 502 is specifically a dichroic mirror, and can transmit the light output by the illumination light source 501 and reflect the light output by the light source 101 and the light output by the fixation light source 301. The magnifying lens 503 is configured to converge the reflected light, and the image pickup lens 507 is configured to form an image of the reflected light on the image pickup device 509.
The light emitted from the illumination light source 501 is irradiated to the anterior segment of the eye E to be inspected, and reflected by the anterior segment to form reflected light, wherein a part of the reflected light is reflected by the cornea of the eye E to be inspected, and a part of the reflected light passes through the cornea to enter the eye E to be inspected, and is diffusely reflected by tissues such as the anterior chamber of the eye E to be inspected.
The reflected light is transmitted to the third reflector 505 through the objective lens 90, the spectroscope 502 and the vision expanding lens 503, is reflected by the third reflector 505, then passes through the image pickup lens 507, is focused to the image pickup device 509 by the image pickup lens 507 to form an image of the anterior ocular segment of the eye to be detected, and the controller 111 collects the image of the anterior ocular segment of the eye to be detected.
In order to make the subject feel comfortable and to avoid a feeling of pressure due to the close contact with the system, the objective lens 90 is disposed to extend forward from the system, and therefore, the distance between the objective lens 90 and the image pickup device 509 is large. In order to determine parameters such as white-to-white distance, the anterior ocular segment imaging module 500 needs to have a larger imaging range, which is in contradiction to the forward extension of the objective lens 90. The view expanding lens 503 is provided to solve this contradiction, and the view expanding lens 503 is configured to change the propagation direction of light reflected by the cornea and light diffusely reflected by the anterior chamber so as to converge, and finally form an image in a wide range on the image pickup device 509.
Referring to fig. 6, in the present embodiment, the illumination light source 501 includes a plurality of illumination lamps 501a, the illumination lamps 501a are uniformly distributed in an annular array, and when the system is in a corneal curvature measurement working condition, a geometric center of an annular shape formed by the illumination lamps 501a is aligned with a pupil center of the eye E to be inspected. Specifically, the illumination lamps 501a are LED lamps, and the number is 4 or more, and preferably, in the embodiment of the present invention, the number of the illumination lamps 501a is 6.
When the system is in a corneal curvature measuring working condition, light emitted by the 6 illumination lamps 501a is irradiated onto the cornea of the eye E to be inspected, reflected by the cornea, and finally detected by the camera 509 after passing through the anterior segment imaging module 500, and a distribution image of the 6 illumination lamps 501a on the cornea is formed on the camera 509. In an embodiment of the present invention, the distribution image is formed together with an image of the anterior segment of the eye to be examined.
The controller 111 collects the images distributed on the cornea by the 6 illuminating lamps 501a, and processes the images by using an algorithm installed in the images to obtain the corneal curvature of the eye to be inspected E, and in the embodiment of the present invention, the controller 111 obtains the corneal central curvature of the eye to be inspected E.
In this embodiment, the anterior segment imaging module 500 further has a function of monitoring the optical path to guide the operator to operate the instrument and to know the related information of the examinee, the system is movably disposed on an operation table, a lower jaw support system is disposed on the operation table, the examiner fixes the head of the examinee by using the lower jaw support system to fix the eye E, so that the fixation mark from the fixation optical module 300 is fixed in the eye E, the examiner controls the movement of the jaw support system and the ophthalmologic measurement system by the operation lever while observing the display screen of the controller 111, so that the anterior segment of the eye E, such as the iris, enters the camera 509 of the anterior segment imaging module 500, and an iris image is presented in the display screen of the controller 111 to guide a doctor in operating an instrument and in understanding information about the eye E to be inspected.
Example two
The present embodiment provides an ophthalmic measurement system (hereinafter, referred to as "system"), which is a basic embodiment of the present invention, and for brevity, the ophthalmic measurement system provided in the present embodiment is the same as the first embodiment, and therefore, the description thereof is omitted, and the first embodiment is incorporated by reference in the present embodiment.
The ophthalmologic measurement system provided by the present embodiment is used for detecting the eye E to be inspected, thereby determining parameters such as the axial length of the eye E to be inspected. Referring to fig. 7, the system includes a main body module 2100, a reference plane 210, a switching scanning element 230, an anterior ocular segment optical path assembly 250, a posterior ocular segment optical path assembly 270, and a light splitting element 280. Referring to fig. 8, preferably, the system further includes an ocular objective 290, a fixation optical module 2300 and an anterior segment imaging module 2500.
In fig. 7, a chain line indicates the system main optical axis L. When the system is in a detection condition, the body module 2100 generates reference light and provides measurement light to the switching scanning element 230, the measurement light is transmitted to the anterior ocular segment optical path component 250 or the posterior ocular segment optical path component 270 according to the rotation angle of the switching scanning element 230, is reflected or transmitted by the light splitting element 280, is focused to a corresponding part of the eye E through the objective lens 290, and is scattered by the eye E to form signal light, the signal light propagates back to the body module 2100 in a direction opposite to the measurement light and interferes with the reference light to generate interference light, and the body module 2100 further collects the interference light.
The reference plane 210 is perpendicular to a line connecting centers of left and right eye pupils of the eye E to be inspected when the system is in a detection working condition, the reference plane 210 includes a first end 211, a second end 213 opposite to and parallel to the first end 211, a third end 215 perpendicular to the first end 211, and a fourth end 217 opposite to and parallel to the third end 215, the first end 211, the second end 213, the third end 215, and the fourth end 217 are connected end to form a closed rectangle, and the first end 211 is close to the eye E to be inspected and close to an emergent main optical axis L when the system is in the detection working condition1Vertically, the third end 215 and the fourth end 217 are parallel to the main emergent optical axis L when the system is in a detection working condition1Said main emergent optical axis L1Which lies in the reference plane 210 when the system is in a detection condition.
It is understood that the reference plane 210 is a virtual plane for describing the position relationship between the components in the system.
Referring to fig. 8, in this embodiment, the main body module 2100 includes a light source 2101, a coupler 2103, a reference arm assembly 2130, a detector 2105, a polarization controller 2107, a focusing lens 2109, and a controller 2111. The reference arm assembly 2130 further includes a reference arm lens 2131 and a reference arm mirror 2133. The light source 2101 may be an OCT light source, which emits weak coherent light with a wavelength of near infrared and transmits the light to the coupler 2103, and the coupler 2103 splits the received light into two beams, wherein one beam is focused by the reference arm lens 2131 and reflected by the reference arm mirror 2133 and then returns to the coupler 2103 as reference light. The other beam is focused by the polarization controller 2107 and the focusing lens 2109, and then transmitted to the switching scanning element 230 as the measuring light.
Referring to fig. 9, the dashed line in fig. 9 illustrates the main optical axis L of the system. In this embodiment, the switching scanning element 230 is located outside the reference plane 210, and the switching scanning element 30 is specifically a galvanometer. The switching scanning element 230 is rotatable about a fixed axis 233, the fixed axis 233 being parallel to the reference plane 210, and the fixed axis 233 being parallel to the first end 211. The switching scanning element 230 has a first operating position 230a and a second operating position 230b and is switchable between the first operating position 230a and the second operating position 230b by rotation about a fixed axis 233. The propagation direction of the measuring light can be selected by controlling the switching scanning element 230 to be at different rotation angles so that the measuring light is transmitted to the anterior ocular segment optical path component 250 or the posterior ocular segment optical path component 270. Specifically, the switching scanning element 230 may be controlled to switch between the first working position 230a and the second working position 230b, and when the switching scanning element 230 is in the first working position 230a, as shown in fig. 9, an included angle between a propagation path of incident light and a propagation path of reflected light at the switching scanning element 230 is β, the measurement light is transmitted to the anterior ocular segment optical path assembly 250; when the switching scanning element 230 is in the second working position 230b, as shown in fig. 9, an included angle between a propagation path of incident light and a propagation path of reflected light at the switching scanning element 230 is α, and the measuring light is transmitted to the posterior segment optical path assembly 270.
Specifically, in this embodiment, the system further includes an electronic control component (e.g., a motor), the electronic control component has an electrically controlled rotating bracket (e.g., a rotating shaft), the electronic control component is electrically connected to the controller 2111, the switching scanning element 230 is fixed on the electrically controlled rotating bracket, the controller 2111 controls the rotation of the electronic control component to drive the electrically controlled rotating bracket to rotate, so as to control the rotation angle of the switching scanning element 230, when the switching scanning element 230 rotates to the first working position 230a, the switching scanning element reflects the measurement light to the anterior ocular segment optical path component 250, and when the switching scanning element 230 rotates to the second working position, the switching scanning element reflects the measurement light to the posterior ocular segment optical path component 270.
It is understood that in other embodiments of the present invention, the system may also control the rotation angle of the switching scanning element 230 through manual adjustment, and specifically, the system includes a rotating bracket for fixing the switching scanning element 230, the rotating bracket provides a knob, and the rotation angle of the switching scanning element 230 is adjusted through manual rotation of the knob to inject the measuring light into the corresponding position of the eye to be inspected E.
It is understood that in other embodiments of the present invention, the switching scanning element 230 may also be controlled to rotate angularly by other mechanical devices or electrical methods, and the design solution satisfying this requirement is within the scope of the present invention, and will not be described herein again.
Referring to fig. 8 again, in this embodiment, the measurement light reaches the light splitting element 280 after passing through the anterior ocular segment optical path component 250 or the posterior ocular segment optical path component 270, and the light splitting element 280 is specifically a half-transmitting half-reflecting mirror, and can transmit the measurement light transmitted by the anterior ocular segment optical path component 250 and reflect the measurement light transmitted by the posterior ocular segment optical path component 270. Specifically, in the present embodiment, when the switching scanning element 230 is in the first working position 230a, the measuring light passes through the beam splitting element 280 and is focused to the anterior segment of the eye E, such as the cornea of the eye E, via the objective lens 290. When the switching scanning element 230 is in the second working position 230b, the measuring light is reflected by the beam splitter 280 and focused to the posterior segment of the eye E, such as the retina of the eye E, via the objective lens 290.
In this embodiment, the anterior ocular segment optical path assembly 250 includes at least one total reflection mirror, i.e. a first reflection mirror 251. When the switching scanning element 230 is in the first working position 230a, the measuring light transmitted by the switching scanning element 230 is reflected to the light splitting element 280 via the first mirror 251.
Preferably, the anterior ocular segment optical assembly 250 includes two total reflection mirrors, a first mirror 251 and a second mirror 255. The first mirror 251 is disposed at the second end 213, and the second mirror 255 is disposed at the first end 211. The intersection point of the system main optical axis L with the first mirror 251 and the intersection point of the system main optical axis L with the second mirror 255 are both located on the reference plane 210. A line connecting an intersection point of the system principal optical axis L with the first reflecting mirror 251 and an intersection point of the system principal optical axis L with the second reflecting mirror 255 is parallel to the third end 215, and a line connecting an intersection point of the system principal optical axis L with the second reflecting mirror 255 and an intersection point of the system principal optical axis L with the light splitting element 280 is parallel to the first end 211. When the switching scanning element 230 is in the first working position 230a, the light transmitted by the switching scanning element 230 is reflected to the light splitting element 280 by the first mirror 251 and the second mirror 255 in sequence.
It should be noted that in this embodiment, the anterior ocular segment optical path assembly 250 further includes at least one relay lens, wherein there is at least one relay lens between the first reflector 251 and the second reflector 255, and when the switching scanning element 230 rotates to the first working position 230a, the first reflector 251 reflects the measuring light to transmit to the second reflector 255 through the relay lens; or at least one relay lens between the second reflecting mirror 255 and the light splitting element 280, in this case, the measuring light is reflected by the second reflecting mirror 255 and irradiated onto the light splitting element 280 through the relay lens.
Preferably, in this embodiment, the anterior ocular segment optical assembly 250 includes two relay lenses, namely a first relay lens 253 and a second relay lens 259, wherein the first relay lens 253 is between the first reflector 251 and the second reflector 255, and the second relay lens 259 is between the second reflector 255 and the beam splitting element 280. The intersection point of the system principal optical axis L and the first relay lens 253 and the intersection point of the system principal optical axis L and the second relay lens 259 are both located on the reference plane 210, the intersection point of the system principal optical axis L and the first reflecting mirror 251, the intersection point of the system principal optical axis L and the second reflecting mirror 255 and the intersection point of the system principal optical axis L and the first relay lens 253 are located on the same straight line, and a connecting line between the intersection point of the system principal optical axis L and the second reflecting mirror 255 and the intersection point of the system principal optical axis L and the second relay lens 259 is parallel to the first end 211. At this time, when the switching scanning element 230 is located at the first working position 230a, the measuring light reflected by the switching scanning element 230 is reflected by the first reflecting mirror 251, transmitted by the first relay lens 253, reflected by the second reflecting mirror 255, transmitted by the second relay lens 259, and then irradiated to the beam splitting element 280.
As shown in fig. 8, in the present embodiment, when the switching scanning element 230 is in the first working position 230a, the beam splitter 280 receives the measurement light from the anterior ocular segment optical path assembly 250, and the measurement light passes through the beam splitter 280 and is focused to the anterior ocular segment of the eye to be inspected E, such as the cornea of the eye to be inspected E, through the objective lens 290. The anterior segment scatters the measurement light to generate an anterior segment signal light, which is irradiated to the light splitting element 280 through the objective lens 290. The anterior ocular segment signal light is divided into a first anterior ocular segment signal light and a second anterior ocular segment signal light by the light splitting element 280, and the second anterior ocular segment signal light is reflected by the light splitting element 280 to enter the posterior ocular segment optical path assembly 270 and does not propagate back to the main body module 2100 any more; the first anterior ocular segment signal light sequentially passes through the light splitting element 280, the anterior ocular segment optical path assembly 250 and the switching scanning element 230 along the direction opposite to the measurement light and is propagated back to the main body module 2100, and interferes with the reference light in the coupler 2103 to generate interference light, and the detector 2105 receives and processes the interference light and transmits the interference light to the controller 2111. Since the polarization direction of the first eye front section signal light is controlled by the polarization controller 2107 before returning to the coupler 2103, the effect of interference is ensured.
In this embodiment, the optical path assembly 270 includes a retroreflective element 271 and an optical element 273, and when the switching scanning element 230 is located at the second working position 230b, the measuring light provided by the switching scanning element 230 is transmitted to the light splitting element 280 after being reflected by the retroreflective element 271 and the optical element 273 in sequence.
Specifically, the optical element 273 may be a total reflection mirror, a half-reflection mirror, or a dichroic mirror, and the geometric center of the optical element 273 is located on the reference plane 210.
The retroreflective element 271 includes a first reflective surface and a second reflective surface. Referring to fig. 9 again, the retroreflective element 271 may be an angular prism, and preferably, the retroreflective element 271 is a right-angle prism. The right-angle prism includes a first reflective surface 271a and a second reflective surface 271b, and the included angle between the first reflective surface 271a and the second reflective surface 271b is preferably set to be a right angle. The retroreflective element 271 and the switching scanning element 230 are oppositely disposed on two different sides of the reference plane 210, a connection line between an intersection point of the system main optical axis L and the first reflective surface 271a and an intersection point of the system main optical axis L and the switching scanning element 230 is perpendicular to the reference plane 210, and a connection line between an intersection point of the system main optical axis L and the second reflective surface 271b and an intersection point of the system main optical axis L and the optical element 273 is also perpendicular to the reference plane 210. When the switching scanning element 230 is in the second working position 230b, the measuring light provided by the switching scanning element 230 is reflected by the first reflecting surface 271a, the second reflecting surface 271b and the optical element 273 in sequence and then transmitted to the beam splitting element 280.
Preferably, the posterior ocular segment optical assembly 270 further comprises a displacement control element (not shown), and the retroreflective element 271 is used for adjusting the optical path. The retroreflective element 271 is fixed to the displacement control element and is movable with the displacement control element in a direction perpendicular to the reference plane, thereby changing the optical path length that the measurement light experiences in the posterior ocular segment optical path assembly 270. The posterior segment optical path assembly 270 further includes a dioptric adjustment unit 275, the dioptric adjustment unit 275 is disposed between the optical element 273 and the beam splitter 280, and the dioptric adjustment unit 275 is movable between the optical element 273 and the beam splitter 280, so that the measurement light can be focused on the posterior segment of the eye E, for example, the retina of the eye E, for different diopters of the eye E. During the movement, the intersection point of the system main optical axis L and the dioptric adjustment unit 275 is always located on the reference plane 210. The refraction adjusting unit 275 may be a lens.
It should be noted that, when measuring the posterior segment of the eye E, since the length of the eye axis of different eyes E is different, it is necessary to provide an optical path adjusting unit in one of the anterior segment optical path component 250 and the posterior segment optical path component 270, and preferably, an optical path adjusting unit, that is, the retroreflective element 271, is provided in the posterior segment optical path component 270.
It is understood that in other embodiments of the present invention, the displacement of the retroreflective element 271 can be calculated by a stepping motor, a voice coil motor, or a grating ruler, a capacitive grating ruler, etc., and is not limited to the above-mentioned moving device or sensor, as long as the structure satisfying such design is within the protection scope of the present invention.
It is understood that in other embodiments of the present invention, the retroreflective element 271 can also be a movable retro-reflector, and the optical path adjustment can be realized only by moving the movable retro-reflector when the optical path adjustment is realized.
In addition, in performing posterior segment measurement of the eye, the position at which the measurement light is focused in the eye E to be inspected can be adjusted by the diopter adjustment member 275, for example, by moving the diopter adjustment member 275 to focus the light on the retina of the eye E to be inspected to achieve measurement of the eye E to be inspected having myopia or hypermetropia. In particular, the refractive adjustment member 275 is mounted on a translation device (not shown) that is manually or electrically controlled to move to achieve refractive adjustment.
In this embodiment, after the measurement light is focused on the posterior segment of the eye E to be inspected, the posterior segment scatters the measurement light and generates a posterior segment signal light, and the posterior segment signal light irradiates the spectroscopic element 280 through the objective lens 290. The signal light of the posterior segment of the eye is divided into a first signal light of the posterior segment of the eye and a second signal light of the posterior segment of the eye by the light splitting element 280, and the first signal light of the posterior segment of the eye enters the optical path component 250 of the anterior segment of the eye after being transmitted by the light splitting element 280 and does not propagate back to the main body module 2100; the second posterior segment signal light is reflected by the light splitting element 280, then sequentially propagates through the posterior segment optical path assembly 270 and the switching scanning element 230 in the direction opposite to the measurement light, and then propagates back to the main body module 2100, and interferes with the reference light in the coupler 2103 to generate interference light, and the detector 2105 receives and processes the interference light and then transmits the interference light to the controller 2111. Since the polarization direction of the second eye posterior segment signal light is controlled by the polarization controller 2107 before returning to the coupler 2103, the effect of interference is ensured.
It is understood that the system can obtain the relevant parameters of the eye E to be inspected, such as the axial length of the eye E to be inspected, by controlling the rotation angle of the switching scanning element 230 to rapidly switch the imaging of the anterior segment or the imaging of the posterior segment of the eye E to be inspected, and by calculating the optical path difference between the imaging of the anterior segment and the imaging of the posterior segment.
Referring to fig. 8 again, in the present embodiment, the system further includes a fixation optical module 2300, and the fixation optical module 2300 includes a fixation light source 2301 and a fixation lens 2303. The light emitted by the fixation light source 2301 is visible light, the fixation light source 2301 is specifically a display screen for displaying a fixation target for the eye E to be inspected to fix vision, and the display screen may be an LCD screen, an OLED screen, or an LED array screen.
Preferably, in this embodiment, the optical element 273 is a dichroic mirror. Specifically, the optical element 273 can transmit light output from the fixation light source 2301 and reflect light output from the light source 2101.
The light emitted by the fixation light source 2301 is transmitted through the fixation lens 2303 and the optical element 273, is adjusted and bent by the refraction adjusting element 275, is reflected by the beam splitter element 280, and is focused on the posterior segment of the eye to be inspected E, such as the retina of the eye to be inspected E, through the objective lens 290.
Specifically, in this embodiment, the fixation position of the eye to be inspected E may be changed using a fixation mark, and the fixation mark may be moved up, down, left, and right, so as to detect different positions of the eye to be inspected. The light emitted from the fixation light source 2301 can adjust diopter through the diopter adjustment element 275, and if the light emitted from the fixation light source 2301 cannot be adjusted to be flexed, the vision fixation mark has different degrees of clarity when observed by the eye to be inspected E with different vision, which makes the eye to be inspected feel uncomfortable when fixed, therefore, preferably, the light path emitted from the fixation light source 2301 is adjusted to be flexed through the diopter adjustment element 275 and then focused on the fundus retina of the eye to be inspected E, so that the eye to be inspected E can see the clear vision fixation mark.
As shown in fig. 8, the system provided in this embodiment further includes an anterior segment imaging module 2500, which is configured to capture an image to determine parameters of the cornea center curvature, the pupil diameter, the white-to-white distance, and the like of the eye E, for example, capture an iris image of the eye E. The anterior segment imaging module 2500 is electrically connected to the controller 2111, and includes: an illumination light source 2501, a beam splitter 2502, a view expanding lens 2503, a third reflector 2505, an imaging lens 2507, and an image pickup device 2509.
Specifically, the illumination light source 2501 is disposed between the objective lens 290 and the eye to be inspected E, and the illumination light source 2501 emits near infrared light. The spectroscope 2502 is specifically a dichroic mirror, and transmits light output by the illumination light source 2501 and reflects light output by the light source 2101 and light output by the fixation light source 2301. The magnifying lens 2503 is configured to converge the reflected light, and the imaging lens 2507 is configured to form an image of the reflected light on the imaging device 2509.
The light emitted from the illumination light source 2501 is irradiated to the anterior segment of the eye E, and reflected by the anterior segment to form a reflected light, wherein a part of the reflected light is reflected by the cornea of the eye E, and a part of the reflected light passes through the cornea, enters the eye E, and is diffusely reflected by tissues such as the anterior chamber of the eye E.
The reflected light is transmitted to the third reflector 2505 through the objective lens 290, the spectroscope 2502 and the vision expanding lens 2503, is reflected by the third reflector 2505, then passes through the camera lens 2507, is focused by the camera lens 2507 to the camera 2509 to form an image of the anterior ocular segment of the eye to be detected, and the controller 2111 acquires the image of the anterior ocular segment of the eye to be detected.
In order to make the subject feel comfortable and to avoid a feeling of pressure due to close contact with the system, the objective lens 290 is disposed to extend forward from the system, and therefore, the distance between the objective lens 290 and the image pickup 2509 is large. In order to determine parameters such as white-to-white distance, the anterior segment imaging module 2500 needs to have a larger imaging range, which is contradictory to the extension of the objective lens 290. The objective of the extended view lens 2503 is to solve this conflict, and the extended view lens 2503 may change the propagation direction of light reflected by the cornea and light diffusely reflected by the anterior chamber so as to converge, and finally form an image in a wide range on the image pickup device 2509.
In this embodiment, the anterior segment imaging module 2500 further has a function of monitoring the optical path to guide the operator to operate the instrument and to know the related information of the examinee, the system is movably disposed on an operation table, a lower jaw support system is disposed on the operation table, the examiner fixes the head of the examinee by using the lower jaw support system to fix the eye E, the fixation mark from the fixation optical module 2300 is fixed behind the eye E, the examiner controls the movement of the jaw support system and the ophthalmologic measurement system by the operation lever while observing the display screen of the controller 2111, so that the anterior segment of the eye E, such as the iris, enters the camera 2509 of the anterior segment imaging module 2500, and an iris image is presented in a display screen of the controller 2111 to guide a doctor in operating an instrument and in understanding information about the eye E to be inspected.
In summary, the ophthalmic measurement system provided by the embodiment of the present invention controls and switches the rotation angle of the scanning element to rapidly switch the anterior segment imaging or the posterior segment imaging of the eye to be examined, and obtains the relevant parameters of the eye to be examined by calculating the optical path difference between the anterior segment imaging and the posterior segment imaging; and the switching scanning element also has a scanning function, so that the scanning of the anterior segment and the posterior segment of the eye to be detected can be realized. Compared with the prior art, the invention provides another technical scheme which can realize the switching of the scanning of the anterior segment and the posterior segment of the eye to be detected so as to determine the axial length of the eye to be detected based on the spectral domain OCT technology, and can overcome the defects of complex structure and high cost in the prior art.
Furthermore, in the ophthalmic measurement system provided by the embodiment of the present invention, the anterior ocular segment optical path component and the posterior ocular segment optical path component are both located on the reference plane, so that the optical path structure can be vertically arranged, the ophthalmic measurement system has a relatively beautiful appearance, and is in line with human engineering, thereby avoiding the oppression on the patient to be measured. On the basis, the switching scanning element can rotate around a certain shaft to realize anterior segment scanning and posterior segment scanning and switch between the anterior segment scanning and the posterior segment scanning, so that the eye to be detected can be scanned in the horizontal direction, and the measuring beam is less prone to be shielded by eyelids and eyelashes due to horizontal scanning.
It will be appreciated that horizontal scanning, i.e. the scanning plane is perpendicular to the reference plane and the scanning plane is drawn across the left and right eye lines of the human eye to be measured.
If the left and right direction size of the system measured person is large, both eyes of the measured person are shielded by the instrument probe when the measured person is measured, and both eyes of the measured person are shielded by a near object when the working distance of the instrument probe is short, so that a strong oppressed feeling is generated, and the measurement experience of the measured person is not facilitated.