Detailed Description
The present invention is described in further detail below with reference to specific embodiments and with reference to the attached drawings, it should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.
Referring to fig. 1, an embodiment of the present invention provides an ophthalmologic inspection system (hereinafter, referred to as "system") for inspecting an eye E by using a measurement light, for example, measuring parameters such as an axial length of the eye E. The ophthalmic test system includes a body module 100, a sample arm 300, and a lateral-eye photographing imaging module 500.
The optical path is illustrated by a dashed-dotted line, the body module 100 generates reference light and provides measurement light to the sample arm 300, the sample arm 300 receives the measurement light and focuses the measurement light on the posterior segment of the eye E, the measurement light is reflected at the posterior segment to generate a posterior segment optical signal, the posterior segment optical signal is reflected back to the sample arm 300, and the sample arm 300 receives the posterior segment optical signal and transmits the posterior segment optical signal to the body module 100.
Synchronously, the side-eye photographing imaging module 500 monitors the position of the anterior ocular segment of the eye to be inspected E, obtains at least one position information of the anterior ocular segment of the eye to be inspected E, and transmits the at least one position information to the main body module 100.
The main body module 100 receives the posterior segment optical signal and the at least one position information, generates a posterior segment interference optical signal by using the reference light to interfere with the posterior segment optical signal, and obtains an eye axial length of the eye E to be inspected by using the posterior segment interference optical signal and the at least one position information.
Specifically, referring to fig. 2, in the embodiment of the present invention, 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 fiber probe 108, 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 adjusted in polarization direction by the polarization controller 107, focused by the focusing lens 109, and transmitted to the sample arm 300 as measurement light.
Wherein the fiber probe 108 and the focusing lens 109 are integrally translatable in a direction parallel to a main optical axis of the focusing lens 109 to adjust an optical path length of the measurement light. Specifically, in the embodiment of the present invention, the system further includes an electronic control assembly (such as a stepping motor, not shown in the figure), the electronic control assembly has an electronic control displacement bracket (not shown in the figure), the electronic control assembly is electrically connected to the controller 111, the optical fiber probe 108 and the focusing lens 109 are fixed on the electronic control displacement bracket, and the controller 111 controls the electronic control assembly to rotate to drive the electronic control displacement bracket to move, so as to control the integral translation of the optical fiber probe 108 and the focusing lens 109.
In an embodiment of the present invention, the sample arm 300 comprises a scanning assembly 330, a sample arm optical path assembly 350, and an objective lens 370.
The scanning assembly 330 includes a horizontal scanning unit 331 and a vertical scanning unit 333, and the measuring light enters the horizontal scanning unit 331 after being focused by the focusing lens 109, enters the vertical scanning unit 333 after being reflected by the horizontal scanning unit 331, and then enters the sample arm optical path assembly 350 after being reflected by the vertical scanning unit 333. The horizontal scanning unit 331 can rotate so that the measurement light scans the posterior segment of the eye E in the horizontal direction, and the vertical scanning unit 333 can rotate so that the measurement light scans the posterior segment of the eye E in the vertical direction.
Specifically, in the embodiment of the present invention, 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 horizontal scanning unit 331 and the vertical scanning unit 333 are fixed on the electrically controlled rotating bracket, and the controller 111 controls the rotation of the electronic control component to drive the electrically controlled rotating bracket to rotate, so as to control the rotation angles of the horizontal scanning unit 331 and the vertical scanning unit 333.
It is understood that in other embodiments of the present invention, the system may also control the rotation angles of the horizontal scanning unit 331 and the vertical scanning unit 333 through manual adjustment, and specifically, the system includes a rotating bracket for fixing the horizontal scanning unit 331 and the vertical scanning unit 333, the rotating bracket provides a knob, and the rotation angles of the horizontal scanning unit 331 and the vertical scanning unit 333 are adjusted through manual rotation of the knob.
It is understood that in other embodiments of the present invention, the horizontal scanning unit 331 and the vertical scanning unit 333 may also be controlled to rotate angularly by other mechanical devices or electrical methods, and the design scheme satisfying this requirement is within the scope of the present invention, and will not be described herein again.
In the embodiment of the present invention, the measuring light reaches the objective lens 370 after passing through the scanning assembly 330 and the sample arm light path assembly 350, and is focused to the posterior segment of the eye to be inspected E, such as the retina of the eye to be inspected E, etc. through the objective lens 370.
The sample arm optical path assembly 350 includes a beam splitter (first beam splitter) 351 and a refractive adjustment element 353. Specifically, the first dichroic mirror 351 is a dichroic mirror, and transmits light emitted from the light source 101 and reflects light emitted from the fixation light source 701. Specifically, the measurement light is transmitted through the first spectroscope 351 and the diopter adjusting element 353 and then transmitted to the objective lens 370, and is finally focused on the posterior segment of the eye E to be inspected; the light emitted from the fixation light source 701 is reflected by the first beam splitter 351, transmitted by the diopter adjustment element 353, and transmitted to the objective lens 370, and finally focused on the posterior segment of the eye E.
The position of the measurement light and the light emitted by the fixation light source 701 focused in the eye E to be inspected can be adjusted by the diopter adjusting element 353, for example, by moving the diopter adjusting element 353 to focus the light on the retina of the eye E to be inspected, so as to realize the measurement of the eye E to be inspected having myopia or hyperopia. In particular, the refractive adjustment member 353 is fixed to a translation device (not shown) and is movable by manual or electrical control to achieve refractive adjustment.
In the embodiment of the present invention, 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 light signal, the posterior segment light signal passes through the objective lens 370 and then propagates back to the main body module 100 through the sample arm light path assembly 350 and the scanning assembly 330 in sequence along the direction opposite to the measurement light, and interferes with the reference light in the coupler 103 to generate a posterior segment interference light signal, and the detector 105 receives the posterior segment interference light signal, processes the posterior segment interference light signal and transmits the processed posterior segment interference light signal to the controller 111. Since the polarization direction of the posterior segment optical signal is controlled by the polarization controller 107 before returning to the coupler 103, the interference effect is ensured.
Referring to fig. 3, in an embodiment of the present invention, the side-eye photographing and imaging module 500 includes at least one camera, and under a detection condition, the at least one camera is disposed on one side of the head H of the subject, the at least one camera is used for photographing a picture of the subject's eye E, the picture of the subject's eye E includes feature points of the subject's eye E, the feature points include a corneal vertex EcOuter frame edge EkAnd the like, which are easily recognized in shape or color. For example, when detecting the left eye of the subject, the at least one camera is disposed on the left side of the head H of the subject, and the camera takes a picture of the left eye; when the right eye of the examinee is detected, the at least one camera is arranged on the right side of the head H of the examinee, and the camera takes a picture of the right eye.
Preferably, the side-eye photographing imaging module 500 includes two cameras, and under the detection condition, the two cameras are respectively disposed on the left side and the right side of the head H of the subject. When detecting the left eye of the examinee, a camera arranged on the left side of the head H of the examinee takes a picture of the left eye of the examinee; when the right eye of the subject is detected, a camera provided on the right side of the head H of the subject takes a picture of the right eye of the subject.
Preferably, the two cameras are telecentric imaging cameras. In this embodiment, the telecentric imaging camera is a double telecentric imaging camera, and in other embodiments of the present invention, the telecentric imaging camera may also be an object-side telecentric imaging camera.
Specifically, the double telecentric imaging camera includes two lenses (a first relay lens 501 and a second relay lens 505), a diaphragm 503 and an imaging device 507, wherein the diaphragm 503 and the second relay lens 505 are disposed between the first relay lens 501 and the imaging device 507, the diaphragm 503 is disposed near the first relay lens 501, and the second relay lens 505 is disposed near the imaging device 507. Specifically, the diaphragm 503 is disposed on the image focal plane of the first relay lens 501, and the center of the diaphragm 503 coincides with the image focal point of the first relay lens 501. Meanwhile, the stop 503 is also located on the object focal plane of the second relay lens 505, and the center of the stop 503 coincides with the object focal point of the second relay lens 505. The center of the image pickup device 507 is located at the image side focal point of the second relay lens 505. The first relay lens 501, the diaphragm 503 and the second relay lens 505 are all arranged perpendicular to the main optical axis of the camera. Under the detection condition, the illumination light emitted by the illumination light source 901 is reflected by the eye E, and the reflected light is transmitted as the image pickup light through the first relay lens 501, the diaphragm 503, the second relay lens 505, and then received by the image pickup device 507, so as to form an image of the eye E.
Referring to fig. 4, in the embodiment of the present invention, the system is disposed on a platform (not shown), the system further includes a chin bar 801, a forehead bar 803 and two forehead bar supports 805, the chin bar 801 and the forehead bar supports 805 are all fixedly disposed on the platform, and the two forehead bar supports 805 and the forehead bar 803 are connected end to form an inverted U-shaped structure. Under the detection condition, the chin of the tested person leans on the chin rest 801, and the forehead leans against the forehead rest 803.
The two cameras are respectively arranged on the two forehead support posts 805. In other embodiments of the present invention, the two cameras may be disposed on the mechanical structure of the sample arm 300, the two cameras may move with the sample arm 300, and the two cameras may be fixedly disposed with respect to the sample arm 300.
Referring to fig. 1 and fig. 2 again, in the embodiment of the present invention, the system further includes a fixation optical module 700, and the fixation optical module 700 includes a fixation light source 701 and a fixation lens 703. The light emitted by the fixation light source 701 is visible light, the fixation light source 701 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, an LED array screen, or the like.
The light emitted from the fixation light source 701 is transmitted through the fixation lens 703 and reflected by the first beam splitter 351, and then is adjusted and bent by the refraction adjusting element 373, and then is focused on the posterior segment of the eye E, such as the retina E of the eye E, via the objective lens 370r。
Specifically, in the embodiment of the present invention, the fixation position of the eye to be inspected E may be changed by using a fixation mark, and the fixation mark may move up and down, left and right, so as to detect different positions of the eye to be inspected. The light emitted by the vision fixation light source 701 can adjust diopter through the diopter adjustment element 353, if the light emitted by the vision fixation light source 701 cannot be adjusted to be bent, 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 vision fixation light source 701 can be focused on the posterior segment retina of the eye after being adjusted to be bent through the diopter adjustment element 353, so that the eye to be inspected can see the clear visual fixation mark.
It should be noted that the system provided by the embodiment of the present invention further includes an iris imaging module 900, which is configured to capture an image required for determining parameters such as a corneal central curvature, a pupil diameter, a white-to-white distance, and the like of the eye E, for example, an iris image of the eye E. The iris imaging module 900 is electrically connected to the controller 111, and includes: an illumination light source 901, a spectroscope 902, a vision expanding lens group, a fifth reflector 905, an image pickup lens group and an image pickup device 913. Specifically, the illumination light source 901 is disposed between the objective lens 370 and the eye E, and the illumination light source 901 emits near infrared light. The dichroic mirror 902 is a dichroic mirror, and transmits light output from the illumination light source 901 and reflects light output from the light source 101 and light output from the fixation light source 701.
The light emitted from the illumination light source 901 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.
In the embodiment of the invention, the vision expanding lens group is used for converging the reflected light and comprises a first vision expanding lens 903 and a second vision expanding lens 907; the image pickup lens group is used for imaging the reflected light on the image pickup device and includes a first image pickup lens 909 and a second image pickup lens 911.
The reflected light is transmitted to the fifth reflector 905 through the objective lens 370, the beam splitter 902 and the first expander lens 903, is reflected by the fifth reflector 905, passes through the second expander lens 907, the first camera lens 909 and the second camera lens 911, is focused by the first camera lens 909 and the second camera lens 911 to the camera 913 to form an image of the anterior segment of the eye to be inspected, and the controller 111 collects the image of the anterior segment of the eye to be inspected.
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 370 is disposed to extend forward from the system, and therefore, the distance between the objective lens 370 and the image pickup device 913 is large. In order to determine parameters such as white-to-white distance, the iris imaging module 900 needs to have a larger imaging range, which is contradictory to the extension of the objective lens 370. The first and second expander lenses 903 and 907 change the propagation directions of light reflected by the cornea and light diffusely reflected by the anterior chamber to converge, and finally form an image of a larger range on the image pickup device 913.
Referring to fig. 5, in the embodiment of the present invention, the illumination light source 901 includes a plurality of illumination lamps 901a, the illumination lamps 901a are uniformly distributed in an annular array, and when the system is in a corneal curvature detection condition, a geometric center of an annular shape formed by the illumination lamps 901a is aligned with a pupil center of the eye E to be detected. Specifically, the illuminating lamps 901a are LED lamps, the number of which is greater than or equal to 4, preferably, in an embodiment of the present invention, the number of the illuminating lamps 901a is 6.
When the system is in the corneal curvature detection condition, light emitted by the 6 illumination lamps 901a is irradiated onto the cornea of the eye E to be detected, reflected by the cornea, and finally detected by the camera 913 through the iris imaging module 900, and a distribution image of the 6 illumination lamps 901a on the cornea is formed on the camera 913. 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 901a, 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.
The iris imaging module 900 of the embodiment of the present invention further has a function of monitoring the light 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 (not shown) on which a chin rest 801 is disposed, the examinee fixes the head H of the examinee using the chin rest system, after the fixation mark from the fixation optical module 700 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 913 of the iris imaging module 900, 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.
In the embodiment of the invention, the lateral eye photographing imaging module is arranged, the position of the anterior ocular segment of the eye to be detected is monitored while the posterior ocular segment of the eye to be detected is detected, and the axial length of the eye to be detected is calculated according to the posterior ocular segment signal light scattered by the posterior ocular segment and the monitored position information of the anterior ocular segment, so that the influence of eye movement in the detection process is avoided, and the accuracy of calculating the axial length of the eye to be detected is improved.
Embodiments of the present invention also provide an ophthalmologic inspection method (hereinafter, simply referred to as "method") for inspecting an eye E to be inspected by using measurement light, for example, parameters such as an eye axial length of the eye E to be inspected.
Referring to fig. 6, the method includes:
and S1, adjusting the optical path of the measuring light.
Specifically, please refer to fig. 7, 2 rectangular frames K in fig. 71、K2The OCT measurement ranges of different parts are represented, the rectangular frame is only schematic, and the actual scanning area can be in a fan-shaped structure and the like. The system includes an initial measurement position RDK1 and a real-time measurement position RDK2, the initial measurement position RDK1 being located on the optical path of the measurement light. In the initial state of the system, each component moves to a respective initial position, which may be a mechanical limit or a reset switch position. In the system initial state, the optical path taken by the measurement light from the coupler 103 to the initial measurement position RDK1 is equal to the optical path taken by the reference light from the coupler 103 to the reference arm mirror 133.
The controller 111 controls the sample arm 300 to be translated in its entirety relative to the system in a direction parallel to the main optical axis of the objective lens 370, the distance Y by which the sample arm 300 is translated in its entirety. Meanwhile, the controller 111 controls the optical fiber probe 108 and the focusing lens 109 to integrally translate relative to the system in a direction parallel to a main optical axis of the focusing lens 109 to adjust an optical path of the measuring light, and a distance of the integral translation of the optical fiber probe 108 and the focusing lens 109 relative to the system is X.
After adjustment, the optical path length that the measurement light traverses from the coupler 103 to the real-time measurement position RDK2 is equal to the optical path length that the reference light traverses from the coupler 103 to the reference arm mirror 133, and the real-time measurement position RDK2 is equal to the retina ErThe distance between the centers of the inner surfaces is smaller than the detection range of the measuring light in the OCT technique. The optical path length of the measuring light from the initial measuring position RDK1 to the retina measuring position RDK2 is (X + Y), the initial measuring position RDK1 and the real-time measurementThe space distance of the quantity position RDK2 is (X + Y)/nha。nhaThe average refractive index of the human eye is a constant.
And S2, imaging the posterior segment of the eye by OCT, and simultaneously shooting a side eye image of the eye to be detected.
The measurement light is focused on the posterior segment of the eye E, the main body module 100 receives the optical signal of the posterior segment returned from the posterior segment, and the side eye photographing imaging module 500 photographs the eye from the side of the eye E to obtain the side eye image Pc of the eye E.
In the preferred embodiment of the present invention, the subject's eye as the left eye is photographed from the left side of the subject, and the subject's eye as the right eye is photographed from the right side of the subject.
And S3, calculating the length of the eye axis.
And interfering the posterior segment optical signals, collecting the interference optical signals of the posterior segment obtained by interference, and calculating the axial length of the eye E according to the interference optical signals of the posterior segment and the side eye image of the eye to be inspected.
Referring to fig. 8, the side-eye photographing imaging module 500 photographs the eye to be inspected E from the side of the eye to be inspected E to obtain a side-eye image Pc of the eye to be inspected E. Corneal vertex Ec and corneal base line L of eye E to be examinedcThe optical path between the two is recorded as the corneal optical path hCornea, the corneal vertex Ec corresponds to the image Ec' on the side eye image Pc, and the corneal base line LcCorresponding image L on side eye image Pcc"the corneal optical distance hCornea satisfies:
wherein, hCornea 'is the number of pixels of hCornea corresponding to the lateral direction of the photosensitive camera of the lateral-eye photographing imaging module 500, W' is the total number of pixels of the lateral direction of the photosensitive camera of the lateral-eye photographing imaging module 500, and h2 is the space width that can be photographed by the lateral-eye photographing imaging module 500, and this value can be obtained by factory calibration of an instrument, and is also a known quantity.
Therefore, the eye axial length Leye of the eye E to be inspected can be obtained:
Leye=△L+X+Y+hRetinal+hCornea
wherein △ L is a corneal reference line L for measuring lightcThe optical path to the initial measurement position RDK1, which is the system calibration quantity, hRetinal is obtained by OCT detection technology.
In other embodiments of the present invention, the two cameras may be disposed on the mechanical structure of the sample arm 300, the two cameras are fixedly disposed with respect to the sample arm 300, and the two cameras may move with the sample arm 300.
In this other embodiment, the eye axis length Leye of the eye E to be inspected can be determined by translating the sample arm 300 by the distance Y in parallel with the main optical axis of the objective lens 370 as a whole:
Leye=△L+X+Y+hRetinal+hCornea-Y
Leye=△L+X+hRetinal+hCornea
in the embodiment of the invention, the position of the anterior ocular segment of the eye to be detected is monitored while the posterior ocular segment of the eye to be detected is detected, and the axial length of the eye to be detected is calculated according to the signal light of the posterior ocular segment scattered by the posterior ocular segment and the monitored position information of the anterior ocular segment, thereby avoiding the influence of eye movement in the detection process and improving the accuracy of calculating the axial length of the eye to be detected.
In other embodiments of the present invention, step S1 may not be included.
According to the embodiment of the invention, the side eye illumination of the eye to be detected is shot at the same time of the OCT imaging of the posterior segment of the eye, the eye axis length of the eye to be detected is calculated, the influence of eye movement on the measurement of the eye axis length is avoided, and the accuracy of calculating the eye axis length of the eye to be detected is improved.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.