CN101791212B - Universal liquid crystal adaptive aberration correcting retina imaging system - Google Patents
Universal liquid crystal adaptive aberration correcting retina imaging system Download PDFInfo
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- CN101791212B CN101791212B CN2009102666641A CN200910266664A CN101791212B CN 101791212 B CN101791212 B CN 101791212B CN 2009102666641 A CN2009102666641 A CN 2009102666641A CN 200910266664 A CN200910266664 A CN 200910266664A CN 101791212 B CN101791212 B CN 101791212B
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Abstract
The invention belongs to the technical field of microscope imaging, relates to a high-order aberration correcting optical design for high-ametropia human eyes, and discloses a universal liquid crystal adaptive aberration correcting retina imaging system. An LCD screen is adopted for displaying a sighting target point light source, and the sighting target is designed into an E shape so that the self-adjusting effect of visibility is enhanced; and meanwhile, E-shaped micro displacement is easily controlled on the LCD screen so that the position of an imaging area can be quantitatively changed. Through the sign of a plurality of key devices, the universality of the liquid crystal adaptive system in fundus imaging is improved, the problem of difficult clear imaging of the fundus adaptive imaging technology under the condition of over 800-degree myopia or 200-degree astigmatism can be solved, and the system can acquire a high-resolution retina image on the human eye of 200-degree astigmatism.
Description
Technical field
The invention belongs to the micro-imaging technique field, the higher order aberratons aberration correcting optical design that relates to height ametropia human eye, specifically a kind of universal liquid crystal adaptive aberration correcting retina imaging system can solve the problem that self adaptive imaging technology myopia or 200 more than 800 degree in optical fundus is spent blur-free imaging difficulty under the astigmatic condition.
Background technology
Blood vessel on the retina is the unique little blood vessel that can directly see clearly of human body, belongs to last vascular system eventually, and any pathologic destruction and angiemphraxis can both cause the downright bad or seepage of breaking of histanoxia.Therefore the optical fundus change is the performance of general disease, the situation of pathological changes is judged in the variation that clinical ophthalmoscope commonly used is observed the optical fundus blood capillary, as cardiovascular and cerebrovascular vessel and endocrine disturbance, and arteriosclerosis, hypertension, central serous chorioretinopathy, diabetic renal papillary necrosis etc.Since the sixties in last century, ophthalmoscope adopts fluorescein fundus angiography, and the image contrast of capillary vessel is increased, can the blood vessel of clear observation diameter more than 20 microns.But eyeball is a complicated optical system, also can not have optical aberration inevitably even there are ametropic eyes, so the blood vessel imaging below 20 microns, and fluorescein fundus angiography is also powerless, let alone observes optic cell.These aberrations are mainly derived from: 1, each refracting media of ophthalmic is in uneven thickness, the surface curvature deviation; 2, each refracting media refractive index of ophthalmic is inhomogeneous; 3, each refracting media disalignment of ophthalmic; 4, dioptric system is not equal to the refractive index of each coloured light.And be to increase the light intensity of imaging and improve the resolution of imaging, often needing platycoria, human eye aberration can aggravate again behind the platycoria, has restricted the effect and the success rate of examination of ocular fundus more.
From the eighties of last century the nineties, people begin to inquire into the application of distorting lens adaptive optics alignment technique in retina image-forming.The wave front aberration of outgoing from eye is measured with Hartmann wave front sensor by system, and the date processing through computer drives distorting lens then and comes aberration for compensation.Distorting lens adaptive optics alignment technique can 500 degree myopia following than healthy eye on the blur-free imaging of 3 microns optic cell profiles of acquisition, but imaging effect just significantly descends when near-sighted degree is spent above 500, tentatively compensate even add near-sighted glasses, blur-free imaging is still very difficult.This is because the present distorting lens driver element number that uses generally is no more than Unit 37, has exceeded the gauged spatial frequency of distorting lens institute energy and increase the higher order aberratons of introducing with near-sighted degree, is also referred to as the spatial resolution of corrector.Although utilize micro-electromechanical technology that the driver element number is increased to more than Unit 2000, this moment, correcting value became problem again, so do not popularize clinical so far.
The driver element of liquid crystal wave-front corrector can reach hundreds of thousands to millions of, and its processing technique is very ripe, and spatial resolution is much higher than traditional distorting lens.By means of the diffraction optics method of kinoform, the correcting range of liquid crystal wave-front corrector can extend to 5 μ m～8 μ m.The response time of liquid crystal is about 10ms, and the emending frequency of LCD self-adapting system is easy to reach 20Hz, satisfies the requirement of the preceding adaptively correcting frequency of glances fully.Liquid crystal wave-front corrector technical maturity in addition, the process-cycle is short, and cost is low, so LCD self-adapting optic system has good application prospects in fundus imaging.
The corrector that has the Chinese invention patent of 4 retina adaptively correcting imaging systems to mention in the system can be liquid crystal corrector (Zhang Yudong, Deng, Chinese invention patent: adaptive optics retina imaging system, ZL99115053.8, ZL99115054.6, ZL99115051.1, ZL99115052.x), wherein adopt light path design altogether in two patents, before corrector, placed 1/4 wavelength plate, make the only garden polarized light of incident corrector, in fact the liquid crystal corrector can not be worked in the polarized light of garden; Other two patents neither be at the optimal design of liquid crystal corrector, place before the human eye beam splitter with the intensity loss of human eye outgoing half, this may be a fatal shortcoming for the system of the bigger liquid crystal corrector of energy loss.
Have only at present Japan reported to 700 the degree near-sighted human eye the optic cell imaging results (" In Vivo measurements of cone photoreceptor spacing in myopic eyesfrom images obtained by an adaptive optics fundus comera; " Y.Kitaguchi, et.al, Jpn.J.Ophthalmol, Vol.51, p456-461,2007), can proofread and correct the more aberration of high myopia though this report is claimed, not provide photo.Optical fundus adaptively correcting image for the astigmatic human eye of 200 degree was not also reported so far.These explanation universality adaptive aberration correcting retina imaging systems also do not design.
A lot of research groups use concavees lens to come the out of focus aberration of compensate for myopia human eye, the astigmatic image error of use post lens compensation astigmatism human eye, but the readability of imaging is still not high enough, explanation is along with the increase of people's ametropia degree, it is serious that higher order aberratons also becomes, want to address this problem, need increase the resolution of detector and corrector simultaneously.
Summary of the invention
The present invention is directed to the problem that prior art exists, optical design based on the liquid crystal adaptive aberration correcting system of diopter regulatory function, in order to be applicable to effective correction of 200 degree astigmatism and the serious human eye of higher order aberratons thereof, simultaneously can quantitative mobile fundus imaging zone, a kind of universal liquid crystal adaptive aberration correcting retina imaging system is provided.
Optical texture of the present invention such as Fig. 1 are made up of sighting target point source 1, first lens 2, second lens 3, PBS polarization beam apparatus (PBS beam splitter) the 4, the 3rd lens 5, linear displacement mechanism 6, human eye 7, lighting source 8, the 4th lens 9, rotation clouded glass 10, the 5th lens 11, aperture diaphragm 12, dichroic coupling beam divider 13, the 6th lens 14, liquid crystal wave-front corrector 15, reflecting mirror 16, the 7th lens 17, Amici prism 18, wave front detector 19, the 8th lens 20, imaging CCD21.Wherein, the sighting target light source that sighting target point source 1 provides human eye to stare, emission wavelength be at visible light wave range, and be single wavelength X ', be positioned at the focus place of first lens 2.First lens 2 and second lens 3 are formed the conjugated lens group, make 1 imaging of sighting target point source.The angle at 45 configuration of the optical axis of the PBS beam splitter 4 and second lens 3 makes the imaging beam of sighting target point source 1 roll over 90 ° on axle.The optical path length d of the 3rd lens 5 to second lens 3
1By the focal distance f of the two
5, f
3D decides with the human eye refractive diopter, and by formula calculate (1), and wherein D does not have unit, and other parameter unit is mm.But human eye 7 is positioned on the head bracket of x-y-z three-dimensional linear displacement, and the x-y plane is vertical with optical axis, regulates head bracket and can make pupil and incident beam centrally aligned.The z direction is parallel to optical axis, and it is f that the adjusting head bracket makes the distance of pupil to the three lens 5 of human eye 7
5
d
1＝(1000-Df
5)f
5/1000+f
3 (1)
In designing like this, sighting target point source 1 of the present invention all can become the virtual image at the front focus place of the 3rd lens 5 with lighting source 8, and this imaging surface is the distance of distinct vision to the oculopupillary distance of tested person.Human eye is stared the sighting target at distance of distinct vision place and is reached vision when clear, can significantly reduce the out of focus aberration.Lighting point light source with distance of distinct vision place illuminates the optical fundus, the light that comes out from fundus reflex becomes flashlight, and be the spherical wave of depolarization, after the outgoing of human eye cornea, carrying cornea reflection interference light and assembling its focus place, arrive PBS beam splitter 4 then by the 3rd lens 5.In the P polarized light outgoing that the transmission end of PBS beam splitter 4 only carries the optical fundus signal, filtered out the S polarization stray light of corneal reflex.The P polarized light is again through becoming the collimated light beam with liquid crystal wave-front corrector 15 apertures couplings behind the 6th lens 14, and the P polarization direction is consistent with the correction polarization direction of liquid crystal wave-front corrector 15.The optical fundus signal beams that projects liquid crystal wave-front corrector 15 is proofreaied and correct back reflection through wave front aberration, becomes converging light through the 6th lens 14 again and separates with incident illumination, arrives reflecting mirror 16 folding axles and assembles the front focus place that images in the 7th lens 17.The light that this picture point is sent is divided into two bundles again through Amici prism 18, a branch of residual aberration that enters after wave front detector 19 detects correction, and another bundle images in CCD21 with eye fundus image under the effect of conjugated lens group the 7th lens 17 and the 8th lens 20.
Be the various higher order aberratons of reply human eye, and can control the position in fundus imaging zone that reach the purpose of the aberration adaptively correcting retina image-forming of universality, the parameter to Primary Component in the system is elaborated below.
Described sighting target point source 1 is made of the TFT-LCD screen, and size is no more than " E " word of 2mm about can showing, " E " is sighting target point source 1.When needs changed the fundus imaging zone, the position of just moving " E " on the LCD screen got final product.For effect is stared in enhancing, the emission wavelength λ ' design of TFT-LCD screen is at visible light wave range, and waveband width is no more than 50nm.The Pixel Dimensions of TFT-LCD screen is at 200 μ m～400 μ m.
Described liquid crystal corrector 15 is pure phase-type reflection type liquid crystal wave-front corrector, position phase modulation depth is 0.95 λ～1.1 λ (λ is the wavelength of lighting source), liquid crystal is to the response time≤15ms of driving voltage, pixel count 〉=512 * 512, number of greyscale levels 〉=50, the corresponding corrector of gray level position is modulated the voltage scale division value of step-length mutually herein, and the position is modulated step-length≤λ/50 mutually.
Described wave front detector 19 is Hartmann's type wave front detector, have 200～300 effective lenticulees, 2mm～5mm receiving aperture, detecting band is the center with the optical wavelength of lighting source, quantum efficiency＞50%, operating frequency 〉=70Hz, measurement error peak-to-valley value≤0.1 λ, root-mean-square value≤0.02 λ.
Described imaging CCD21 reads noise≤7 electronics during at light wave strong point quantum efficiency＞50% of lighting source, at read-out speed 10MHz, pixel count 〉=512 * 512.
Described lighting source 8 is a single-mode laser, its wavelength X ≠ λ ', and shoot laser forms point source through the single-mode fiber coupling, and power is in 10mW～20mW scope.
Described first lens 2, second lens 3, the 3rd lens 5, the 4th lens 9, the 5th lens 11, the 6th lens 14, the 7th lens 17, the 8th lens 20 are two gummed achromats.
Described PBS beam splitter 4 in illumination light wavelength λ is the wave band at center with 1 * 10
-3The good polarization characteristic of extinction ratio sees through P light, and folded light beam S polarisation of light characteristic is not had quantitative requirement.
Described linear displacement mechanism 6 is the one dimension displacement device, displacement accuracy 1mm, stroke 80mm.
Described rotation clouded glass 10 is the sheet glass of a surface through frosted, has 75%～80% transmitance, is rotated speed of rotation scope 1000rpm～2000rpm continuously by Electric Machine Control.
Described aperture diaphragm 12 is a circular aperture, and the aperture can be regulated in the 10mm scope continuously at 1mm.Aperture diaphragm 12 also can be annular diaphragm, produces annular beam incident human eye, directly the strong reflection stray light in filtering eye cornea normal incidence zone.
Described dichroic coupling beam divider 13 has the ability of the sighting target light that illumination light that reflection wavelength is λ and transmission peak wavelength be λ '.
Described reflecting mirror 16 is the thin, planar reflecting mirror, and the minute surface diameter or the length of side are 10mm～15mm, thickness 1mm～2mm.
Described Amici prism 18 is common Amici prism.
In the present invention, liquid crystal adaptive aberration correcting retina imaging system has been carried out the parameter designing of Primary Component, make it and effectively to proofread and correct the above simple near-sighted human eye of 800 degree, and can effectively proofread and correct 200 degree astigmatism and the serious human eye of higher order aberratons thereof, form the LCD self-adapting optics eyeground imaging system of universality.
Description of drawings
Fig. 1 is an optical texture sketch map of the present invention.Wherein, 1 is the sighting target point source, and 2 is first lens, and 3 is second lens, 4 is the PBS beam splitter, and 5 is the 3rd lens, and 6 is linear displacement mechanism, and 7 is human eye, 8 is lighting source, and 9 is the 4th lens, and 10 are rotation clouded glass, and 11 is the 5th lens, 12 is aperture diaphragm, and 13 is the dichroic coupling beam divider, and 14 is the 6th lens, 15 is the liquid crystal wave-front corrector, and 16 is reflecting mirror, and 17 is the 7th lens, 18 is Amici prism, and 19 is wave front detector, and 20 is the 8th lens.21 are imaging CCD." E " on the sighting target point source 1 can move, and is used for changing the fundus imaging zone.Liquid crystal wave-front corrector 15 and wave front detector 19 in the system possess very high resolution, can satisfy the higher order aberratons alignment requirements of the astigmatic human eye of 200 degree.
Fig. 2 is that 200 degree astigmatism have the retina optic cell image that the near-sighted human eye of 200 degree obtains concurrently in system of the present invention, and wherein (a) is for before proofreading and correct, (b) for after proofreading and correct.
The specific embodiment
1) adopt 3.5 inches TFT-LCD screens, Pixel Dimensions 300 μ m, the narrow band pass filter of 510nm～550nm is placed in the front, makes centre of luminescence wavelength X ' be 530nm, drives the LCD screen and makes its " E " that demonstrates 1.5mm as sighting target point source 1.
2) used lighting source 8 is a small semiconductor laser, has optical fiber coupling, core diameter 100 μ m, and emission wavelength λ is 808nm, output is in that 10mW～the 20mW scope is adjustable.
3) first lens 2, second lens 3, the 3rd lens 5, the 4th lens 9, the 5th lens 11, the 6th lens 14, the 7th lens 17, the 8th lens 20 are two gummed achromats, and the surface is coated with anti-reflection film.Bore is followed successively by: 20mm, 25mm, 25mm, 10mm, 20mm, 40mm, 20mm, 20mm; Focal length is followed successively by: 150mm, 250mm, 200mm, 30mm, 50mm, 250mm, 86mm, 100mm.
4) selecting human eye 7 is that 200 degree astigmatism have 200 degree myopia concurrently, and it is 250mm that its distance of distinct vision 200mm, linear adjustment displacement mechanism 6 make the optical path length of the 3rd lens 5 to second lens 3, is being stabilized in 6mm than pupil diameter under the dark situation.
5) manufacture rotation clouded glass 10, choosing thickness is the frosted thin glass sheet of 1mm, and the optical fundus illumination is 75% with the transmitance of laser.The frosted thin glass sheet is pasted on the machine shaft, and motor rotates with the speed of 1000rpm, thereby has eliminated laser speckle effect.
6) used aperture diaphragm 12 adopts 1mm to the 10mm aperture of adjusting continuously, be close to the 5th lens 11 after.Because tested pupil diameter is 6.0mm, so the diameter of aperture diaphragm 12 is controlled to 7.3mm, makes its conjugate image be slightly less than pupil.
7) used dichroic coupling beam divider 13, bore 25mm has 95% reflectance to the optical fundus illumination light of 808nm wavelength, and the sighting target light of 550nm wavelength is had 95% transmitance.
8) used PBS beam splitter 4, diameter 50mm, the extinction ratio of the P polarized light of telling when the optical fundus of 808nm wavelength illumination light sees through is 1 * 10
-3
9) used liquid crystal corrector 15, the reflective LCOS device of pure phase-type, position phase modulation depth is 0.97 λ (785nm), 512 * 512 of pixel counts, 50 gray levels, elemental area 15 μ m * 15 μ m, the response time 15ms in electric field, reflectance 61%.
10) used reflecting mirror 16, area 15mm * 15mm, thickness 2mm, reflectance 95%.
11) used Amici prism 18 is common Amici prism, and the saturating inverse ratio of 808nm wavelength optical fundus illumination light is about 1: 1.
12) used wave front detector 19, Hartmann's type, effectively the lenticule number is m=233, the 2.5mm receiving aperture, and the CCD of configuration produces for ANDOR company, model EM-DV897,128 * 128 pixels, quantum efficiency is 70% at 808nm wavelength place, Wavefront detecting speed 200Hz, measurement error peak-to-valley value 0.05 λ, root-mean-square value 0.01 λ.
13) used imaging CCD21, ANDOR company produces, model EM-DV897,512 * 512 pixels, time of exposure 15ms.
14) utilize said elements to build diopter self-regulation liquid crystal adaptive aberration correcting retina image optics structure according to light path shown in Figure 1, dispose Self Adaptive Control and signal processing subsystem, formed the diopter self-regulation adaptive aberration correcting imaging system of complete function.
15) for pupil can be aimed at incident light axis expediently, the pupil camera is set to be demarcated pupil position: place an infrared LED in human eye front upper place 20mm～30mm distance, emission wavelength 830nm～900nm, illumination measured pupil makes pupil image in the focus place of second lens 3.Between second lens 3 and dichroic coupling beam divider 13, insert a color separation film again, make the light beam vertical reflection of infrared LED go out light path, do not pass through less than illumination and the sighting target light beam of 830nm but do not influence wavelength.Folding axle focal plane place at second lens 3 is provided with the pupil camera, places diffuse-reflectance screen at the design attitude of pupil and replaces human eye.Open lighting source 8, a border circular areas is illuminated on the radiation shield, and the center of this speck is the position that pupil center should locate.Open the pupil camera and take the speck that diffuse-reflectance is shielded.With this speck center is the center of circle, and basic pupil radius 3mm is that radius is drawn a circle, as the normal place of pupil, this circle is saved in file, deposits in the program-con-trolled computer.Close lighting source 8, withdraw from the diffuse-reflectance screen.
16) the human eye pupil is aimed at the step of incident light axis: the circle that will go up the labelling pupil position of step acquisition appends to pupil image of camera viewing area, is that standard is aimed at pupil with this circle.Open sighting target point source 1, the coarse adjustment headstock is so that human eye can be seen sighting target.Open the pupil camera, the human eye pupil is recorded a video, the fine tuning headstock overlaps with the demarcation circle up to pupil image.
17) set up the response matrix R of 19 pairs of wave-front correctors 15 of wave front detector: at first human eye 7 usefulness simulated eyes are substituted; Simulated eye is made up of a cemented doublet and diffuse-reflectance screen, and wherein the focal length of cemented doublet is 20mm, and anthropomorphic dummy's crystalline lens is placed on residing position, protoplast's eye pupil hole, and diffuse-reflectance screen simulation retina is placed on the residing position of former human eye retina.Open lighting source 8, can on the diffuse-reflectance screen, see the convergence luminous point.Open wave front detector 19 and can detect, move forward and backward and regulate the peak-to-valley value minimum of diffuse-reflectance screen on tested wavefront from the wavefront of simulated eye outgoing.Open the response matrix measurement control software then, measure the preceding response matrix R of preceding 36 Zernike mode waves.
The response matrix basic principle of measurement: making the coefficient of each front of Zernike multinomial is 1, is unit with the wavelength X, solves the face morpheme phase numerical solution of 36 Zernike items respectively; Utilize position phase-gray scale response relation of surveying good liquid crystal wave-front corrector 15 in advance, successively with each Zernike multinomial Z
K(x, face morpheme phase numerical value y) converts the grey level distribution figure on the liquid crystal corrector 15 to, is applied to one by one on the liquid crystal wave-front corrector 15 by computer then.Computer is read the slope distribution of lenticule focal spot array on x axle and y axle of wave front detector 19 corresponding every Zernike patterns.Because first for translational mode can omit, thus the two-dimensional matrix R of one 2 * (M-1) row, 2 * m row formed by these a series of wavefront slope,
K is a Zernike multinomial item ordinal number herein, and k is M=36 to the maximum, so k=2 ... 36; M is the effective lenticule number on Hartmann's detector, 233.This two-dimensional matrix is response matrix R.
18) remove simulated eye, measured human eye 7 is positioned at position shown in Figure 1, the adaptively correcting imaging process on beginning human eye optical fundus: at first light sighting target point source 1, make us the initiatively sighting target at staring imaging face place of eye, and clear up to vision.Successively open rotation clouded glass 10, imaging CCD21 and lighting source 8, the time of exposure of imaging CCD21 is set to 15ms.Wave front detector 19 receives the light that reflects through human eye 7, and its wavefront is converted into 2m train wave front slope vector, m=233 herein:
Then by
(a is the coefficient a of each front of Zernike multinomial
kThe vector that constitutes) have:
Formula can obtain the preceding Zernike equation of institute's probing wave in view of the above, solves the position phase numerical value on the wavefront.According to the position of liquid crystal wave-front corrector 15 and the relation of gray level, wavefront position phase numerical value is converted to gray level feeds back to liquid crystal wave-front corrector 15, liquid crystal wave-front corrector 15 carries out wavefront correction.Imaging CCD21 works always, notes the optical fundus retinal images before and after proofreading and correct, as Fig. 2.
19) analysis result:
The 200 degree astigmatism of taking before and after the adaptively correcting have the optic cell image of the near-sighted human eye of 200 degree concurrently shown in Fig. 2 (a) and (b), find out that the adaptively correcting effect is remarkable, the picture that does not also see Chu by what information of Fig. 2 (a) before proofreading and correct is seen behind the aberration correction Fig. 2 (b) optic cell image of 3 μ m diameters clearly.The optic cell image that obtains on such high astigmatism human eye yet there are no so far and published, and has shown universality effect of the present invention.
Claims (5)
1. a universal liquid crystal adaptive aberration correcting retina imaging system is characterized in that by sighting target point source (1), first lens (2), second lens (3), PBS beam splitter (4), the 3rd lens (5), linear displacement mechanism (6), human eye (7), lighting source (8), the 4th lens (9), rotation clouded glass (10), the 5th lens (11), aperture diaphragm (12), dichroic coupling beam divider (13), the 6th lens (14), liquid crystal wave-front corrector (15), reflecting mirror (16), the 7th lens (17), Amici prism (18), wave front detector (19), the 8th lens (20), imaging CCD (21) constitutes; Wherein first lens (2) and second lens (3) are formed the conjugated lens group, make sighting target point source (1) imaging; The 5th lens (11) are formed the conjugated lens group with second lens (3) by dichroic coupling beam divider (13), and the optical path length between the two is the focal distance f of second lens (3)
3, the picture of lighting source (8) is overlapped with the picture of sighting target point source (1); Second lens (3) and the 3rd lens (5) are formed the conjugated lens group by PBS beam splitter (4), and aperture diaphragm (12) is imaged in human eye pupil place; The 6th lens (14) form confocal configuration with second lens (3) by PBS beam splitter (4), and make its focus depart from the L distance to the left, L is 4mm～6mm, and the two-beam that makes incident and reflect liquid crystal wave-front corrector (15) is eccentric by the 6th lens (14) about respectively; The 7th lens (17) and the 8th lens (20) are the conjugated lens groups, and the distance between the two is the former focal length, and light beam is gone up imaging at imaging CCD (21) after by the conjugated lens group; Wave front detector (19) is by Amici prism (18) and the 7th lens (17) conjugation, and the optical path length between the two is the focal length of the 7th lens (17);
Described sighting target point source (1) is positioned at the focus place of first lens (2), and PBS beam splitter (4) and the angle at 45 configuration of the optical axis of second lens (3) make the imaging beam of sighting target point source (1) roll over 90 ° on axle; The 3rd lens (5) are to the optical path length d of second lens (3)
1By the focal distance f of the two
5, f
3D decides with the human eye refractive diopter, by formula d
1=(1000-Df
5) f
5/ 1000+f
3Calculate, wherein D does not have unit, and other parameter unit is mm; Human eye (7) but be positioned on the head bracket of x-y-z three-dimensional linear displacement, the x-y plane is vertical with optical axis, the z direction is parallel to optical axis; Rotation clouded glass (10) places the focal plane place of the 5th lens (11) and the 4th lens (9), and aperture diaphragm (12) is close to the 5th lens (11) afterwards, and adjustment aperture is controlled pleasing to the eye light beam and is slightly less than the oculopupillary diameter of tested person; Dichroic coupling beam divider (13) places aperture diaphragm (12) afterwards, be inserted between first lens (2) and second lens (3), form and the angle at 45 configuration of two vertical each other optical axises, two vertical each other optical axises are meant that the optical axis of the 4th lens (9), the 5th lens (11) is vertical with the optical axis of first lens (2) and second lens (3) composition conjugated lens group; Liquid crystal wave-front corrector (15) places the focus of the 6th lens (14), and it proofreaies and correct the polarization direction and the P polarized light coincide; Reflecting mirror (16) is placed with the optical axis of the 6th lens (14) and the 7th lens (17) angle at 45, with light beam folding axle; In the middle of the 7th lens (17) and the 8th lens (20), place Amici prism (18), collimated light beam is divided into vertical each other two bundles, vertically to light beam enters wave front detector (19), and directly to light beam enters the imaging CCD (21) that places the 8th lens (20) focus place;
The sighting target light source that described sighting target point source (1) provides human eye to stare, emission wavelength be at visible light wave range, and be single wavelength X '; Regulate head bracket and make pupil and incident beam centrally aligned, it is f that the adjusting head bracket makes the distance of pupil to the three lens (5) of human eye (7)
5Lighting source (8) is the laser point light source, and its wavelength X is decided according to the fundus imaging optical properties of tissue, and λ ≠ λ '; Dichroic coupling beam divider (13) reflection end and transmission end are distinguished the light of indirect illumination light, transmission sighting target light source respectively towards aperture diaphragm (12) and first lens (2), form the common light path of two light beams and enter follow-up system;
Described sighting target point source (1) can become the virtual image at the front focus place of the 3rd lens (5) with lighting source (8), and this imaging surface is the distance of distinct vision to the oculopupillary distance of tested person; Illuminate the flashlight on optical fundus with the lighting point light source at distance of distinct vision place, come out to become the spherical wave of depolarization from fundus reflex, after the outgoing of human eye cornea, carrying cornea reflection interference light and assembling its focus place, arriving PBS beam splitter (4) then by the 3rd lens (5); In the P polarized light outgoing that the transmission end of PBS beam splitter (4) only carries the optical fundus signal, filtered out the S polarization stray light of corneal reflex; The P polarized light is again through becoming the collimated light beam with liquid crystal wave-front corrector (15) aperture coupling behind the 6th lens (14), and the P polarization direction is consistent with the correction polarization direction of liquid crystal wave-front corrector 15; The optical fundus signal beams that projects liquid crystal wave-front corrector (15) is proofreaied and correct back reflection through wave front aberration, become converging light through the 6th lens (14) again and separate, arrive reflecting mirror (16) folding axle and assemble the front focus place that images in the 7th lens (17) with incident illumination; The light that this picture point is sent is divided into two bundles again through Amici prism (18), a branch of residual aberration that enters after wave front detector (19) detects correction, another bundle images in imaging CCD (21) with eye fundus image under the effect of conjugated lens group the 7th lens (17) and the 8th lens (20).
2. universal liquid crystal adaptive aberration correcting retina imaging system according to claim 1 is characterized in that:
Described sighting target point source (1) is made of TFT-LCD screen, makes the LCD screen demonstrate " E " word that size up and down is no more than 2mm, and " E " is as the sighting target point source;
Described liquid crystal corrector (15) is pure phase-type reflection type liquid crystal wave-front corrector, position phase modulation depth is 0.95 λ～1.1 λ, liquid crystal is to the response time≤15ms of driving voltage, pixel count 〉=512 * 512, gray level 〉=50, the corresponding corrector of gray level position is modulated the voltage scale division value of step-length mutually herein, and the position is modulated step-length≤λ/50 mutually;
Described wave front detector (19) is Hartmann's type wave front detector, have 200～300 effective lenticulees, 2mm～5mm receiving aperture, detecting band is the center with the optical wavelength of lighting source, quantum efficiency＞50%, operating frequency 〉=70Hz, measurement error peak-to-valley value≤0.1 λ, root-mean-square value≤0.02 λ;
Described imaging CCD (21) reads noise≤7 electronics during at light wave strong point quantum efficiency＞50% of lighting source, at read-out speed 10MHz, pixel count 〉=512 * 512;
Described lighting source (8) is a single-mode laser, and shoot laser forms point source through the single-mode fiber coupling, and power is in 10mW～20mW scope;
Described first lens (2), second lens (3), the 3rd lens (5), the 4th lens (9), the 5th lens (11), the 6th lens (14), the 7th lens (17), the 8th lens (20) are two gummed achromats;
Described PBS beam splitter (4) in illumination light wavelength λ is the wave band at center with 1 * 10
-3The polarization characteristic of extinction ratio sees through P light, and folded light beam S polarisation of light characteristic is not had quantitative requirement;
Described linear displacement mechanism (6) is the one dimension displacement device, displacement accuracy 1mm, stroke 80mm;
Described rotation clouded glass (10) is the sheet glass of a surface through frosted, has 75%～80% transmitance, is rotated speed of rotation scope 1000rpm～2000rpm continuously by Electric Machine Control;
Described aperture diaphragm (12) is a circular aperture, and the aperture is regulated in the 10mm scope continuously at 1mm;
Described dichroic coupling beam divider (13) has the ability of the sighting target light that illumination light that reflection wavelength is λ and transmission peak wavelength be λ ';
Described reflecting mirror (16) is the thin, planar reflecting mirror, and the minute surface diameter or the length of side are 10mm～15mm, thickness 1mm～2mm;
Described Amici prism (18) is common Amici prism.
3. universal liquid crystal adaptive aberration correcting retina imaging system according to claim 2 is characterized in that just moving the position of " E " on the LCD screen when needs change the fundus imaging zone.
4. universal liquid crystal adaptive aberration correcting retina imaging system according to claim 3, the emission wavelength λ ' that it is characterized in that the TFT-LCD screen is at visible light wave range, waveband width is no more than 50nm, and the Pixel Dimensions of TFT-LCD screen is at 200 μ m～400 μ m.
5. universal liquid crystal adaptive aberration correcting retina imaging system according to claim 2 is characterized in that:
1) adopt 3.5 inches TFT-LCD screens, Pixel Dimensions 300 μ m, the narrow band pass filter of 510nm～550nm is placed in the front, makes centre of luminescence wavelength X ' be 530nm, drives the LCD screen and makes it demonstrate 1.5mm " E ";
2) used lighting source (8) is a small semiconductor laser, core diameter 100 μ m, and emission wavelength λ is 808nm;
3) first lens (2), second lens (3), the 3rd lens (5), the 4th lens (9), the 5th lens (11), the 6th lens (14), the 7th lens (17), the 8th lens (20) surface all are coated with anti-reflection film, and bore is followed successively by: 20mm, 25mm, 25mm, 10mm, 20mm, 40mm, 20mm, 20mm; Focal length is followed successively by: 150mm, 250mm, 200mm, 30mm, 50mm, 250mm, 86mm, 100mm;
4) thickness of rotation clouded glass (10) frosted thin glass sheet is 1mm, and the optical fundus illumination is 75% with the transmitance of laser; The frosted thin glass sheet is pasted on the machine shaft, and motor is with the speed rotation of 1000rpm;
5) used aperture diaphragm (12), the aperture that adopts 1mm to regulate continuously to 10mm, tested pupil diameter is 6.0mm, the diameter of aperture diaphragm (12) controls to 7.3mm;
6) used dichroic coupling beam divider (13), bore 25mm has 95% reflectance to the optical fundus illumination light of 808nm wavelength, and the sighting target light of 550nm wavelength is had 95% transmitance;
7) used PBS beam splitter (4), diameter 50mm, the extinction ratio of the P polarized light of telling when the optical fundus of 808nm wavelength illumination light sees through is 1 * 10
-3
8) used liquid crystal corrector (15), the reflective LCOS device of pure phase-type, position phase modulation depth is that 0.97 λ is 785nm, 512 * 512 of pixel counts, 50 gray levels, elemental area 15 μ m * 15 μ m, the response time 15ms in electric field, reflectance 61%;
9) used reflecting mirror (16), area 15mm * 15mm, thickness 2mm, reflectance 95%;
10) used Amici prism (18) is about 1: 1 to the saturating inverse ratio of 808nm wavelength optical fundus illumination light;
11) the effective lenticule number of used wave front detector (19) is m=233,2.5mm receiving aperture, the CCD of configuration produces for ANDOR company, model EM-DV897,128 * 128 pixels, quantum efficiency is 70% at 808nm wavelength place, Wavefront detecting speed 200Hz, measurement error peak-to-valley value 0.05 λ, root-mean-square value 0.01 λ;
12) used imaging CCD (21) produces model EM-DV897,512 * 512 pixels, time of exposure 15ms for ANDOR company.
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| CN102551658A (en) * | 2010-12-09 | 2012-07-11 | 苏州生物医学工程技术研究所 | Human eye aberration correcting imaging system based on phase diversity |
| JP5850637B2 (en) * | 2011-04-27 | 2016-02-03 | キヤノン株式会社 | Fundus imaging apparatus, fundus imaging apparatus control method, and program |
| CN102499633B (en) * | 2011-09-30 | 2013-09-25 | 中国科学院长春光学精密机械与物理研究所 | Large-visual-field liquid-crystal self-adapting optical eyeground imaging method |
| CN102429636B (en) * | 2011-09-30 | 2013-07-03 | 中国科学院长春光学精密机械与物理研究所 | Crystal liquid self-adaptive optical fundus imaging system with large field of view |
| CN103271717B (en) * | 2013-05-30 | 2014-12-24 | 中国科学院长春光学精密机械与物理研究所 | Visibility-adjustable adaptive optical fundus camera |
| CN104382554A (en) * | 2014-11-07 | 2015-03-04 | 中国科学院上海光学精密机械研究所 | Laser scanning ophthalmoscope with staring function |
| CN106063700B (en) * | 2016-05-24 | 2017-07-25 | 中国科学院长春光学精密机械与物理研究所 | The quick seizure of fine vascular and imaging method below 10 microns of eyeground |
| DE102017108193A1 (en) * | 2017-04-18 | 2018-10-18 | Rowiak Gmbh | OCT imaging apparatus |
| CN110907420B (en) * | 2019-12-04 | 2021-07-02 | 中国科学院过程工程研究所 | Device for measuring mass transfer equilibrium time between immiscible solution and liquid phase and measuring method using device |
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