CN102727172A - System and method for measuring eyeball parameters by using weak coherent technology - Google Patents
System and method for measuring eyeball parameters by using weak coherent technology Download PDFInfo
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- CN102727172A CN102727172A CN2012102033123A CN201210203312A CN102727172A CN 102727172 A CN102727172 A CN 102727172A CN 2012102033123 A CN2012102033123 A CN 2012102033123A CN 201210203312 A CN201210203312 A CN 201210203312A CN 102727172 A CN102727172 A CN 102727172A
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Abstract
The invention relates to a system and a method for measuring eyeball parameters by using a weak coherent technology. The system comprises a scaleplate light source, a signal light source, a photoelectric sensor, a photoelectric detector, a scaleplate light source sample arm, a scaleplate light source reference arm, a signal light source reference arm, a signal light source zero arm, a signal light source sample arm, an illumination board imaging light path, a signal conditioning unit and a data processing unit. The method comprises the following steps of: calculating all biological parameters of eyeballs once accurately by taking the scaleplate light source as an inner source scaleplate and utilizing interference waveforms of the scaleplate light source sample arm and the scaleplate light source reference arm, interference waveforms of the signal light source reference arm and the signal light source zero arm, interference waveforms of the signal light source reference arm and the signal light source sample arm and the imaging of the illumination board imaging light path, wherein the biological parameters comprise corneal thickness, anterior chamber depth, crystal thickness, vitreous body thickness and eye axial length. Due to the adoption of a unique optical delay line, the system and the method are high in signal to noise ratio and quick and accurate in measurement.
Description
Technical field
The invention belongs to field of ophthalmology, relate to the measuring technique of optical instrument, be specifically related to system and measuring method that the weak coherent technique of a kind of usefulness is measured the eyeball parameter at ophthalmology.
Background technology
Along with the development of the new diagnosis and treatment technology of ophthalmology, like carrying out of the implant surgery of cataract extraction associating intra-ocular artificial lens, optical activity operation on cornea in the wrong, the bio-measurement technology of eyeball also more and more receives numerous clinicians' attention.
The bio-measurement of bulbous length (axial eye length measurement) is exactly to use various relevant inspection methods the structural parameters of eyeball are measured; Measure like the axial length of corneal thickness, ACD, lens thickness, vitreous chamber length and eyeball, extraocular muscles thickness, optic nerve diameter, periorbital thickness etc., for the diagnosis and the treatment of ocular disease provides foundation.The accurate parameter that how to obtain each ingredient of eyeball is the direction that people study always, and any small error can make perfect operation can not get ideal effect.
At present the bio-measurement appearance of bulbous length commonly used is ultrasonic measurement, and is ultra like A, and its principle is that the emission ultrasound wave reflects at the interface of each tissue through human eye, utilizes the amplitude of echo impulse to confirm the positional information of each tissue.
Above-mentioned traditional ultrasonic A is ultra measure exist measure sequential contact cornea (cross infection), alignment uncertain (influenced by operator's maneuver), compressing anterior chamber, to problems such as special eye (high myopia, posterior scleral staphyloma and the distortion of eyeball rear wall) precision are not high.
Occurred in recent years the OCT technology is applied to the instrument that the axis oculi biological parameter is measured; Roughly be divided into two types: one type is adopted partially coherent interference technique (Partial Coherence Interferometer; PCI); The weak coherent reflection measurement technology of another kind of employing (Low Coherence Reflectometry, LCR).Adopt the instrument of PCI technology, axiallength uses optical interference techniques to measure, and ACD (ACD) is measured through slit lamp, and corneal curvature uses and is integrated in the conventional geometric optical method for measuring in the instrument; Adopt the instrument of LCR technology; The eyeball biological parameter can be measured through single pass; Measure the interference peaks position of cornea front and rear surfaces, crystal front and rear surfaces and retina front and rear surfaces through coherent reflection measurement technology principle a little less than the optics, thereby draw axis oculi and anterior chamber, crystal and Vitrea thickness.With traditional ultrasonic A superfacies ratio, adopt the instrument of optical interference techniques to have advantages such as non-cpntact measurement, certainty of measurement high (10um, ultrasonic 100um), automatic aligning.But adopt the parameter of the technological instrument one-shot measurement of PCI on the low side, even pass through the parameter that other means are measured eyeballs, crystal and Vitrea thickness also can't be measured; Adopt the instrument of LCR technology, the biological parameter of eyeball can one-shot measurement, but Signal-to-Noise is low, needs repeatedly to measure the stack back and improves signal to noise ratio, has influenced measuring speed.
Through the domestic literature retrieval, find two pieces of publication documents relevant with present patent application:
1, a kind of intermittent scanning optical delay line (CN101430422) based on inclination parabolic type bus helical reflecting mirror, this kind comprises based on the intermittent scanning optical delay line of inclination parabolic type bus helical reflecting mirror: inclination parabolic type bus helical reflecting mirror, back-reflection mirror, drive motors.Inclination parabolic type bus helical reflecting mirror comprises convex-surface type inclination parabolic type bus helical reflecting mirror and concave shape inclination parabolic type bus helical reflecting mirror, and the back-reflection mirror is used to control the intermittent scanning optical delay line former road reflection that light beam is tilted parabolic type bus helical reflecting mirror.
2, a kind of linked optical delay linear system (CN101706597A); It comprises optical fiber collimator, secondary reflection mirror, grating, focusing arrangement and optics galvanometer; It is characterized in that: said secondary reflection mirror is fixedly connected on the adjustment rack of said optical fiber collimator; Said secondary reflection mirror and said optical fiber collimator form linkage structure, and the light direction of said optical fiber collimator is vertical with the minute surface of said secondary reflection mirror; Angle between the normal direction of said grating and the light direction of said optical fiber collimator is the first-order diffraction angle of said grating; Said grating and galvanometer lay respectively at the along of said focusing arrangement.
Through the technology contrast, above-mentioned two pieces of publication documents have the different of essence with present patent application.
Summary of the invention
The objective of the invention is to overcome the deficiency of prior art, provide the weak coherent technique of a kind of usefulness to measure the system and the measuring method of eyeball parameter, this method signal to noise ratio is high, measures quick and precisely, and the focusing precision is high.
The present invention solves its technical problem and takes following technical scheme to realize:
The weak coherent technique of a kind of usefulness is measured the system of eyeball parameter; Comprise scale light source, photoelectric sensor, scale light source sample arm, scale light source reference arm, signal optical source, photodetector, signal optical source reference arm, signal optical source arm at zero point, signal optical source sample arm, illumination plate imaging optical path, signal condition unit and data processing unit; Said scale light source and photoelectric sensor are divided into scale light source sample arm and scale light source reference arm through fiber coupler, and scale light source reference arm is provided with wavelength division multiplexer and optical delay line; Said signal optical source and photodetector are divided into signal optical source reference arm, signal optical source arm at zero point and signal optical source sample arm through fiber coupler; Photoelectric sensor and photodetector all are connected with the signal condition unit; The signal condition unit is connected with data processing unit, and innovative point of the present invention is:
Said signal optical source reference arm is connected with the wavelength division multiplexer of scale light source reference arm, and the optical delay line after signal optical source optical signal and the shared wavelength division multiplexer of scale light source light signal constitutes the endogenous scale of signal optical source thus.
And; Said optical delay line comprises rotating disk, drive motors, horizontal hollow corner cube prism, hangs down and put hollow corner cube prism, reflecting mirror and condenser lens; The drive motors that drives dial rotation is installed in the bottom, axis position of rotating disk; Planar outer rim radial equipartition is equipped with a plurality of horizontal hollow corner cube prisms on rotating disk; Between adjacent hollow corner cube prism, installing hangs down puts the hollow corner cube prism, is provided with the reflecting mirror perpendicular to light path at the disk edge side, and the light path between this reflecting mirror and the horizontal hollow corner cube prism is provided with a condenser lens.
And; The signal optical source of said signal optical source sample arm is corresponding to the illumination plate of gathering cornea to be tested, and the signal optical source sample arm of illumination plate front end is provided with liquid lens, said liquid lens and provides the data processing unit of its work control voltage to be connected.
And; Said illumination plate and scale light source, photoelectric sensor, scale light source sample arm, scale light source reference arm, signal optical source, photodetector, signal optical source reference arm, signal optical source arm at zero point, signal optical source sample arm and illumination plate imaging optical path position relative fixed, scale light source sample arm, scale light source reference arm, signal optical source reference arm, signal optical source arm at zero point and signal optical source sample arm form the light path of interference wave and the distance condition of illumination plate imaging optical path blur-free imaging satisfies simultaneously.
A kind of utilization is the method for systematic survey eyeball parameter according to claim 1, and measuring process is following:
(1) start-up system: light scale light source, signal optical source, illumination plate, respectively install on and off switch in the closed-system;
(2) illumination plate source imaging: the reflection of illumination plate light source through cornea after the imaging of illumination plate imaging optical path on data processing unit display image;
(3) dynamically obtain interference wave: the distance of adjustment illumination plate and cornea makes the imaging that shows on the data processing unit clear; Regulate scale light source sample arm, scale light source reference arm, signal optical source reference arm, signal optical source arm at zero point, the liquid lens focal length through change in voltage conditioning signal light source sample arm, each following interference signal waveform of show rulers light source and signal optical source optical signal on data processing unit:
1. the optical signal of scale light source form to be interfered after through scale light source sample arm and scale light source reference arm and on data processing unit, is shown;
2. the optical signal of signal optical source form to be interfered after through signal optical source sample arm and signal optical source reference arm and on data processing unit, is shown;
3. the optical signal of signal optical source form to be interfered after through signal optical source arm at zero point and signal optical source reference arm and on data processing unit, is shown;
(4) accurately obtain the distance of illumination plate and cornea: the distance that moves forward and backward illumination plate and cornea; Simultaneously also at the light path of conditioning signal light source to cornea; Utilize in the above-mentioned steps (3) 3. zero point the arm interference peaks and step (3) in 2. cornea interference peaks accurately confirm the distance of illumination plate and cornea; When the distance when being designed distance of zero point arm interference peaks and cornea interference peaks, fixing this distance;
(5) measure cornea curvature and cornea transverse diameter and PD: utilize the illumination plate source imaging to calculate cornea curvature, cornea transverse diameter and PD after accurately obtaining the distance of illumination plate and cornea by data processing unit;
(6) frequency multiplication is obtained: the Doppler frequency deviation that utilize in the above-mentioned steps (3) 1., two kinds of interference waveforms 3. obtains two kinds of interference waves calculates the multiplier parameter of two kinds of interference waves again through the Doppler frequency deviation of two kinds of interference waves;
(7) interference signal of restituted signal light source reference arm and sample arm: the multiplier parameter that utilizes above-mentioned steps (6) changes to the frequency of scale light source on the carrier frequency of signal optical source and generates the two-way orthogonal signalling, utilizes two-way orthogonal signalling restituted signal light source reference arm to be the corresponding reflection envelope signal of each organizational structure of eye with the interference signal of sample arm;
(8) double sampling: the interference crest that utilizes the scale light source changes into positional information with the reflection envelope signal of step (7);
(9) calculate: the interference crest that utilizes the scale light source is as endogenous position scale, utilizes the envelope waveform after the number of the interference waveform of scale light source goes to measure demodulation, calculates the data of each organizational structure of human eye.
Advantage of the present invention and good effect are:
1, the present invention need not demarcate the integrated endogenous high accuracy of optical delay line scale to the retardation and the rotational angle of optical delay line, and certainty of measurement does not receive the at the uniform velocity influence of property of dial rotation.
2, optical delay line of the present invention has been eliminated the kinetic light beam of delay line and has been moved through horizontal hollow corner cube prism and upright hollow corner cube prism, thereby can add lens light beam is focused on, to improve signal to noise ratio.
3, the present invention is owing to adopted unique band scale optical delay line; And scale light source sample arm, scale light source reference arm, signal optical source reference arm, signal optical source arm at zero point and signal optical source sample arm form the light path of interference wave and the distance condition of illumination plate imaging optical path blur-free imaging satisfies simultaneously; So can one time high accuracy measure all biological parameter of eyeball; Comprise corneal thickness, ACD, crystal thickness, vitreous body thickness, axiallength, corneal curvature, and cornea transverse diameter and PD.
4, the present invention since adopted unique optical delay line, horizontal and upright hollow prism after methods such as condenser lens, dynamic liquid condenser lens and dynamic demodulation in the light path; Signal to noise ratio is high; Need not adopt repeatedly synergetic method to improve signal to noise ratio, measure quick and precisely.
5, the present invention when measuring the crystal front and rear surfaces owing to adopted the liquid lens liquid that changes focal length with magnitude of voltage, the signal to noise ratio when having improved greatly to each layer tissue focusing range finding of eye.
Description of drawings
Fig. 1 is the johning knot composition of system of the present invention;
Fig. 2 is an optical delay line structure enlarged drawing of the present invention;
Fig. 3 is the structure chart of liquid lens of the present invention with change in voltage;
Fig. 4 is that the present invention calculates two kinds of used interference waveform figure of frequency multiplication, and wherein (a) is the interference waveform figure of scale light source reference arm and sample arm, (b) is the interference waveform figure of signal optical source arm at zero point and reference arm;
Fig. 5 is an interference peaks and the oscillogram of cornea interference peaks at zero point of the present invention;
Fig. 6 is the interference crest figure of each layer tissue of human eye among the present invention.
The specific embodiment
Below in conjunction with accompanying drawing the embodiment of the invention is done further detailed description; It is emphasized that; Embodiment of the present invention is illustrative, rather than determinate, so the present invention is not limited to the embodiment described in the specific embodiment; Every other embodiments that drawn by those skilled in the art's technical scheme according to the present invention belong to the scope that the present invention protects equally.
The weak coherent technique of a kind of usefulness is measured the system of eyeball parameter; As shown in Figure 1; Comprise scale light source 1, photoelectric sensor 2, scale light source sample arm, scale light source reference arm, signal optical source 25, photodetector 26, signal optical source reference arm, signal optical source arm at zero point, signal optical source sample arm, illumination plate imaging optical path, signal condition unit 24 and data processing unit 22, said scale light source and photoelectric sensor are through fiber coupler H
1Be divided into scale light source sample arm and scale light source reference arm, scale light source reference arm is provided with wavelength division multiplexer 9 and optical delay line 11; Said signal optical source and photodetector are through fiber coupler H
223 are divided into signal optical source reference arm, signal optical source arm at zero point and signal optical source sample arm, and photoelectric sensor and photodetector all are connected with the signal condition unit, and the signal condition unit is connected with data processing unit, and innovative point of the present invention is:
Said signal optical source reference arm is connected with the wavelength division multiplexer of scale light source reference arm, and the optical delay line after signal optical source optical signal and the shared wavelength division multiplexer of scale light source light signal constitutes the endogenous scale of signal optical source thus.
As shown in Figure 2; Said optical delay line comprises rotating disk 27, drive motors 28, horizontal hollow corner cube prism 29, hangs down and put hollow corner cube prism 30, reflecting mirror 31 and condenser lens 32; The drive motors that drives dial rotation is installed in the bottom, axis position of rotating disk; Planar outer rim radial equipartition is equipped with a plurality of horizontal hollow corner cube prisms on rotating disk; Between adjacent hollow corner cube prism, installing hangs down puts the hollow corner cube prism, is provided with the reflecting mirror perpendicular to light path at the disk edge side, and the light path between this reflecting mirror and the horizontal hollow corner cube prism is provided with a condenser lens.Directive horizontal hollow corner cube prism behind the flashlight entering optical delay line; Penetrate behind 180 ° of the horizontal hollow corner cube prism direct light signals; The optical signal that penetrates shines to hang down puts the hollow corner cube prism; Hang down and to penetrate back horizontal hollow corner cube prism after putting 180 ° of hollow corner cube prism direct light signals, the ejaculation behind 180 ° of the direct light signals again of horizontal hollow corner cube prism shines reflecting mirror F behind the optical signal line focus lens of ejaculation
2, optical signal is through reflecting mirror F
2The former road of reflection tailing edge is returned.
The signal optical source of said signal optical source sample arm is corresponding to the illumination plate 18 of gathering cornea 17 to be tested; The signal optical source sample arm of illumination plate front end is provided with liquid lens 15, as shown in Figure 3, and said liquid lens is connected with the data processing unit that its work control voltage is provided.
Said signal optical source reference arm is that as shown in Figure 1, signal optical source light is through fine bonder H
2, Polarization Controller P
34 are connected with the wavelength division multiplexer of scale light source reference arm, and the signal optical source optical signal gets into wavelength division multiplexer, the collimator Z of said scale light source reference arm
2The shared same optical delay line in back.
Said scale light source reference arm and scale light source sample arm are that as shown in Figure 1, said scale light source and photoelectric sensor connect fiber coupler H respectively through single-mode fiber
1, this fiber coupler is told two ways of optical signals, wherein the corresponding plane mirror F of one road optical signal
18, this road optical signal is provided with Polarization Controller P
15 and collimator Z
17, optical signal is through reflecting mirror F
1It is scale light source reference arm that this light path is returned on former road, reflection back, the corresponding plane mirror F of another road optical signal
2, this road optical signal is provided with Polarization Controller P
26, wavelength division multiplexer and collimator Z
210, this collimator Z
2The optical signal directive optical delay line that penetrates, and give plane mirror F through the optical delay line reflection
2, optical signal is through reflecting mirror F
2Former road, reflection back is returned.
Said signal optical source arm at zero point and signal optical source sample arm are that as shown in Figure 1, said signal optical source and photodetector connect fiber coupler H respectively through single-mode fiber
2This fiber coupler is told three road optical signals, and wherein the first via is above-mentioned signal optical source reference arm, the corresponding plane mirror F of the second road optical signal
314, this road optical signal is provided with Polarization Controller P
412 and collimator Z
313, optical signal is through reflecting mirror F
3Former road, reflection back is returned, and this light path is a signal optical source arm at zero point; The corresponding cornea to be tested of Third Road optical signal is disposed with liquid lens and beam splitter 19 on this road optical signal, optical signal returns on former road after each structure reflection of ocular tissue, and this light path is the signal optical source sample arm.
Said illumination plate imaging optical path does; On signal optical source sample arm light path, between beam splitter and cornea, be mounted with an illumination plate perpendicular to signal optical source light, evenly settle LED illumination plate light source 16 on the illumination plate; The illumination plate source light is through after the reflection of cornea; Reflex to imaging len 20 through beam splitter, through imaging on image pick off 21 behind the imaging len, imaging signal is delivered to data processing unit and is handled again.
Said illumination plate and scale light source, photoelectric sensor, scale light source sample arm, scale light source reference arm, signal optical source, photodetector, signal optical source reference arm, signal optical source arm at zero point, signal optical source sample arm and illumination plate imaging optical path position relative fixed, scale light source sample arm, scale light source reference arm, signal optical source reference arm, signal optical source arm at zero point and signal optical source sample arm form the light path of interference wave and the distance condition of illumination plate imaging optical path blur-free imaging satisfies simultaneously.
Described liquid lens is applied to the voltage swing on the liquid lens through the data processing unit change; As shown in Figure 3; Through the shape of voltage change regulator solution surface, change in voltage scope 30v-60v, the shape of lens surface can become convex surface continuously from concave surface; The burnt excursion of light to 13D, realizes the sequential focusing from the cornea to the optical fundus from-5D.
A kind of utilization is the method for systematic survey eyeball parameter according to claim 1, and measuring process is following:
(1) start-up system: light scale light source, signal optical source, illumination plate, respectively install on and off switch in the closed-system;
(2) illumination plate source imaging: the reflection of illumination plate light source through cornea after the imaging of illumination plate imaging optical path on data processing unit display image;
(3) dynamically obtain interference wave: the distance of adjustment illumination plate and cornea makes the imaging that shows on the data processing unit clear; Regulate scale light source sample arm, scale light source reference arm, signal optical source reference arm, signal optical source arm at zero point, the liquid lens focal length through change in voltage conditioning signal light source sample arm, each following interference signal waveform of show rulers light source and signal optical source optical signal on data processing unit:
1. the optical signal of scale light source form to be interfered after through scale light source sample arm and scale light source reference arm and on data processing unit, is shown;
2. the optical signal of signal optical source form to be interfered after through signal optical source sample arm and signal optical source reference arm and on data processing unit, is shown;
3. the optical signal of signal optical source form to be interfered after through signal optical source arm at zero point and signal optical source reference arm and on data processing unit, is shown;
(4) accurately obtain the distance of illumination plate and cornea: the distance that moves forward and backward illumination plate and cornea; Simultaneously also at the light path of conditioning signal light source to cornea; Utilize in the above-mentioned steps (3) 3. zero point the arm interference peaks and step (3) in 2. cornea interference peaks accurately confirm the distance of illumination plate and cornea; When the distance when being designed distance of zero point arm interference peaks and cornea interference peaks, fixing this distance;
(5) measure cornea curvature and cornea transverse diameter and PD: utilize the illumination plate source imaging to calculate cornea curvature, cornea transverse diameter and PD after accurately obtaining the distance of illumination plate and cornea by data processing unit;
(6) frequency multiplication is obtained: the Doppler frequency deviation that utilize in the above-mentioned steps (3) 1., two kinds of interference waveforms 3. obtains two kinds of interference waves calculates the multiplier parameter of two kinds of interference waves again through the Doppler frequency deviation of two kinds of interference waves;
(7) interference signal of restituted signal light source reference arm and sample arm: the multiplier parameter that utilizes above-mentioned steps (6) changes to the frequency of scale light source on the carrier frequency of signal optical source and generates the two-way orthogonal signalling, utilizes two-way orthogonal signalling restituted signal light source reference arm to be the corresponding reflection envelope signal of each organizational structure of eye with the interference signal of sample arm;
(8) double sampling: the interference crest that utilizes the scale light source changes into positional information with the reflection envelope signal of step (7);
(9) calculate: the interference crest that utilizes the scale light source is as endogenous position scale, utilizes the envelope waveform after the number of the interference waveform of scale light source goes to measure demodulation, calculates the data of each organizational structure of human eye.
Operation principle of the present invention is:
Said scale light source sample ami light signal and scale light source reference arm light signal interfere at the photoelectric sensor place; Said signal optical source reference arm light signal and signal optical source sample ami light signal interfere at the photodetector place; Said signal optical source arm at zero point optical signal and signal optical source reference arm light signal interfere on photodetector; Above-mentioned three kinds of interference light signals are delivered to the signal condition unit through photoelectric sensor or photodetector, and the signal condition unit delivers to that data processing unit is handled and display waveform is used for calculating after to the interference light signal filter amplifying processing; Because scale light source sample ami light signal and signal optical source reference arm light signal are same optic path, shared same optical delay line is so constituted the endogenous scale of this system.
Instance:
As shown in Figure 1; The scale light source adopts narrow line source, and an instance is to select wavelength 1310nm, the DFB of bandwidth 10MHz (Distributed Feed Back) laser instrument; Other narrow line sources that meet the requirements (coherence length is greater than delay line change in optical path length amount) all can be selected; The scale light source is divided into two-way optical fiber through single-mode fiber and 2 * 2 fiber coupler H1, and one the tunnel is scale light source source reference arm, and light beam is through Polarization Controller P
1Adjust the laggard optics collimator Z of going into of polarization state
1, become vertical directive plane mirror F behind the collimated light
1, through plane mirror F
1Former road, reflection back is returned, through 2 * 2 fiber coupler H
1After, getting into photoelectric sensor, the signal condition unit is delivered to data processing unit after to the interference light signal filter amplifying processing and is handled and display waveform;
Another road sign chi light source source sample arm, light beam is through Polarization Controller H
1The adjustment polarization state is laggard goes into wavelength division multiplexer.Simultaneously; The flashlight of signal optical source, SLED (Super luminescent LED) wideband light source (centre wavelength 830nm, half high bandwidth 20 ~ 40nm) that instance is wavelength 830nm; Can certainly use other satisfactory wideband light sources, the flashlight light source is through 3 * 3 bonder H
2Being divided into three the tunnel, the one tunnel is flashlight reference arm and above-mentioned scale light source process wavelength division multiplexer and collimator Z
2After directive optical delay line together; Shine by the circumference uniform distribution horizontal behind the optical signal entering optical delay line and be installed on the horizontal hollow corner cube prism on the rotating disk; Penetrate behind 180 ° of the horizontal hollow corner cube prism direct light signals; The optical signal that penetrates shines by circumference uniform distribution and is vertically mounted on vertical the putting on the hollow corner cube prism on the rotating disk; Hang down and to penetrate back horizontal hollow corner cube prism after putting 180 ° of hollow corner cube prism direct light signals, shine reflecting mirror F behind the optical signal line focus lens of horizontal hollow corner cube prism ejaculation
2, optical signal is through reflecting mirror F
2Reflection tailing edge former road is returned, and interferes at the photoelectric sensor place with the optical signal of scale light source sample arm; Said rotating disk is by the coaxial driven by motor rotation that is installed in the rotating disk below.Described horizontal hollow corner cube prism is put the hollow corner cube prism and all is fixed on the rotating disk with hanging down, and rotates towards a direction with rotating disk.After putting the reflection of hollow corner cube prism through hanging down like this, parallel beam is oppositely penetrated and is got back to horizontal hollow corner cube prism, is not limited to the hollow corner cube prism certainly here, and other optics that similarly can realize this function can.According to reflection of light and hollow corner cube prism characteristic; Though dial rotation; But the light beam of directive condenser lens does not move, and passes through the once more focusing shaping of condenser lens to light beam, thereby can improve the signal to noise ratio of the light echo efficient lifting whole system of delay line.
Described scale light source is that narrow line source and flashlight wideband light source use same optical delay line, and the Doppler frequency deviation of two light sources is than the strict inverse ratio that equals two light source center wavelength.The interference waveform signal to noise ratio of the narrow line source of scale light source is fixed, and can accurately obtain Doppler frequency deviation from the interference waveform of scale light source reference arm and sample arm (optical delay line), shown in Fig. 4 (a).The waveform of frequency deviation after through data processing unit acquired signal conditioning cell processing calculates, and the interference signal of signal optical source arm at zero point and reference arm can be by adjusting plane mirror F
2Longitudinal separation obtain, shown in Fig. 4 (b), the waveform of the frequency deviation of signal optical source after through data processing unit acquired signal conditioning cell processing calculates, thereby can draw the multiplier parameter of two-way light source.Can accurately obtain the carrier wave of flashlight wideband light source through multiplier parameter, thereby the interference signal of flashlight is carried out the quadrature demodulation demodulation.Optical delay line has the velocity variations greater than 10% in rotary course, bring thus to surpass 10% Doppler frequency deviation variation.If directly measuring-signal is carried out amplitude demodulation, required bandwidth is greater than the quadrature demodulation demodulation scheme that uses frequency conversion to follow the tracks of.Such as the Doppler frequency deviation central value of 830nm signal optical source at 2MHz; Then frequency deviation region is that 1.9MHz is to 2.1MHz; And the frequency of modulated signals is less than 40KHz, uses the bandwidth of amplitude demodulation scheme LPF can not be less than 250KHz, otherwise can cause signal to noise ratio to lose.And the quadrature demodulation demodulation scheme that uses frequency conversion to follow the tracks of, the LPF after the demodulation can be less than 40KHz, because noise bandwidth reduces, the noise specific energy improves 6～8dB.
Described liquid lens can be through applying voltage the shape of size adjustment liquid surface, as shown in Figure 3, voltage is applied to 60v from 30v; The shape of lens surface can become convex surface continuously from concave surface, and focal power can change to 13D, can realize the sequential focusing from the cornea to the optical fundus from-5D; For crystalline front and rear surfaces, reflectance hangs down 3 to 4 times than the reflectance of cornea, and the crystal front surface is a convex surface; After being reflected, disperses more signal beams; Adopt the liquid lens of dynamic focusing, can make signal beams focus on the crystal front and rear surfaces, can significantly improve the interference signal signal to noise ratio of crystal front and rear surfaces through data processing unit controlling liquid lens voltage.
Described flashlight arm at zero point has two effects, and one is to use in the aforementioned calculation multiplier parameter, and another effect is exactly accurately to confirm cornea and the vertical dimension of measuring the corneal curvature illumination plate; As shown in fig. 1; Circumferentially be uniformly distributed with 6 light emitting diode point sources on the illumination plate, point source reflexes to imaging len through after the reflection of cornea through beam splitter; Through on the image pick off, forming images behind the imaging len; Because corneal curvature is different, the position of 6 equidistant point sources on same diameter circle can change, thereby signal processing unit can calculate corneal curvature through the position that the image on the imageing sensor extracts point; Can know from said process; The vertical dimension of corneal curvature illumination plate and cornea has very big influence to measurement result, and variable in distance can directly influence the position of pip on the cornea, measures corneal curvature and must accurately confirm the vertical dimension of cornea illumination plate to cornea.Flashlight arm at zero point of the present invention can guarantee accurately to confirm the position of cornea; Through flashlight arm at zero point can increase by one zero point interference peaks, as shown in Figure 5, zero point, interference peaks was the starting point of optical delay line; The position of cornea interference peaks can accurately be obtained by illustrated waveform; Only move forward and backward whole device, be equivalent to the distance of portable lighting plate and measured object (human eye), when the cornea interference peaks and zero point interference peaks distance when being designed distance; Data processing unit is just caught the image point position of point source on the imageing sensor, and further processing can draw corneal curvature.
During each the measurement; The data processing unit acquired signal is nursed one's health unitary signal, mainly is the interference signal of two photodetectors, and data processing unit at first detects the interference waveform at zero point of signal optical source; Illumination plate and signal optical source sample arm and imaging optical path all are fixed together; To regulate illumination plate and be in order to narrate conveniently, nearest part is exactly an illumination plate because machine installs back digression film, and the distance of regulating instrument and cornea intuitively looks to seem the distance of accent illumination plate and cornea; But be equivalent in fact simultaneously at the light path of conditioning signal light source to cornea; Being transferred to suitable distance (interference condition that meets signal optical source, flashlight are wideband light source, and interference length the is very short) interference peaks of cornea and the interference peaks of its hetero-organization of intraccular part just can come out; Cornea formed images on ccd to the light path of cornea and eyes to the distance of illumination plate, the signal optical source that the cornea interference peaks can occur satisfy relation clearly and be designed to identical; As long as promptly satisfy one of them, two other satisfies simultaneously, when promptly regulating instrument and make illumination plate be setting value to the distance of cornea to the distance of cornea; Also satisfy simultaneously the light path interference condition of flashlight, eyes are also the most clear through the picture that imaging len becomes on ccd simultaneously.
Regulate the relative position of whole device and measured object; Up to the cornea interference peaks and zero point interference peaks distance be setting value; This moment, date processing unit went out corneal curvature through the position of the picture point on the imageing sensor and the image calculation of human eye, and cornea transverse diameter and PD.According to the interference waveform of flashlight interference waveform at zero point and scale light source reference arm and signal arm (optical delay line), can calculate the multiplier parameter of scale light source in addition with respect to the flashlight frequency deviation.After calculating multiplier parameter, data processing unit forwards the change of scale light source (1310nm) carrier wave on the carrier frequency of signal optical source (830nm) to according to multiplier parameter, generates two-way quadrature square-wave signal simultaneously.Data processing unit multiplies each other the two-way quadrature square-wave signal of the interference waveform of signal optical source sample arm and reference arm and described generation, obtained the envelope after the demodulation behind quadratic sum, evolution and the LPF, and the envelope of the dead-center position that the envelope after the demodulation obtains through the scale that obtains from the scale light source with from flashlight after to demodulation carries out double sampling, and the abscissa of envelope is transformed into position coordinates; Export A line data then, as shown in Figure 6, a. anterior surface of cornea interference peaks; B. posterior surface of cornea interference peaks, c. crystal front surface interference peaks, surperficial interference peaks behind the d. crystal; E. retina interference peaks can once calculate all biological parameter of eyeball accurately according to the position at each peak, comprises corneal thickness; ACD; Crystal thickness, vitreous body thickness, and axiallength.
Claims (5)
1. system of measuring the eyeball parameter with weak coherent technique; Comprise scale light source, photoelectric sensor, scale light source sample arm, scale light source reference arm, signal optical source, photodetector, signal optical source reference arm, signal optical source arm at zero point, signal optical source sample arm, illumination plate imaging optical path, signal condition unit and data processing unit; Said scale light source and photoelectric sensor are divided into scale light source sample arm and scale light source reference arm through fiber coupler, and scale light source reference arm is provided with wavelength division multiplexer and optical delay line; Said signal optical source and photodetector are divided into signal optical source reference arm, signal optical source arm at zero point and signal optical source sample arm through fiber coupler; Photoelectric sensor and photodetector all are connected with the signal condition unit; The signal condition unit is connected with data processing unit, it is characterized in that:
Said signal optical source reference arm is connected with the wavelength division multiplexer of scale light source reference arm, and the optical delay line after signal optical source optical signal and the shared wavelength division multiplexer of scale light source light signal constitutes the endogenous scale of signal optical source thus.
2. the weak coherent technique of usefulness according to claim 1 is measured the system of eyeball parameter; It is characterized in that: said optical delay line comprises rotating disk, drive motors, horizontal hollow corner cube prism, hangs down and put hollow corner cube prism, reflecting mirror and condenser lens; The drive motors that drives dial rotation is installed in the bottom, axis position of rotating disk; Planar outer rim radial equipartition is equipped with a plurality of horizontal hollow corner cube prisms on rotating disk; Between adjacent hollow corner cube prism, installing hangs down puts the hollow corner cube prism, is provided with the reflecting mirror perpendicular to light path at the disk edge side, and the light path between this reflecting mirror and the horizontal hollow corner cube prism is provided with a condenser lens.
3. the weak coherent technique of usefulness according to claim 1 is measured the system of eyeball parameter; It is characterized in that: the signal optical source of said signal optical source sample arm is corresponding to the illumination plate of gathering cornea to be tested, and the signal optical source sample arm of illumination plate front end is provided with liquid lens, said liquid lens and provides the data processing unit of its work control voltage to be connected.
4. measure the system of eyeball parameter according to coherent technique a little less than claim 1 or the 3 described usefulness; It is characterized in that: said illumination plate and scale light source, photoelectric sensor, scale light source sample arm, scale light source reference arm, signal optical source, photodetector, signal optical source reference arm, signal optical source arm at zero point, signal optical source sample arm and illumination plate imaging optical path position relative fixed, scale light source sample arm, scale light source reference arm, signal optical source reference arm, signal optical source arm at zero point and signal optical source sample arm form the light path of interference wave and the distance condition of illumination plate imaging optical path blur-free imaging satisfies simultaneously.
5. one kind is utilized the method for systematic survey eyeball parameter according to claim 1, and it is characterized in that: measuring process is following:
(1) start-up system: light scale light source, signal optical source, illumination plate, respectively install on and off switch in the closed-system;
(2) illumination plate source imaging: the reflection of illumination plate light source through cornea after the imaging of illumination plate imaging optical path on data processing unit display image;
(3) dynamically obtain interference wave: the distance of adjustment illumination plate and cornea makes the imaging that shows on the data processing unit clear; Regulate scale light source sample arm, scale light source reference arm, signal optical source reference arm, signal optical source arm at zero point, the liquid lens focal length through change in voltage conditioning signal light source sample arm, each following interference signal waveform of show rulers light source and signal optical source optical signal on data processing unit:
1. the optical signal of scale light source form to be interfered after through scale light source sample arm and scale light source reference arm and on data processing unit, is shown;
2. the optical signal of signal optical source form to be interfered after through signal optical source sample arm and signal optical source reference arm and on data processing unit, is shown;
3. the optical signal of signal optical source form to be interfered after through signal optical source arm at zero point and signal optical source reference arm and on data processing unit, is shown;
(4) accurately obtain the distance of illumination plate and cornea: the distance that moves forward and backward illumination plate and cornea; Simultaneously also at the light path of conditioning signal light source to cornea; Utilize in the above-mentioned steps (3) 3. zero point the arm interference peaks and step (3) in 2. cornea interference peaks accurately confirm the distance of illumination plate and cornea; When the distance when being designed distance of zero point arm interference peaks and cornea interference peaks, fixing this distance;
(5) measure cornea curvature and cornea transverse diameter and PD: utilize the illumination plate source imaging to calculate cornea curvature, cornea transverse diameter and PD after accurately obtaining the distance of illumination plate and cornea by data processing unit;
(6) frequency multiplication is obtained: the Doppler frequency deviation that utilize in the above-mentioned steps (3) 1., two kinds of interference waveforms 3. obtains two kinds of interference waves calculates the multiplier parameter of two kinds of interference waves again through the Doppler frequency deviation of two kinds of interference waves;
(7) interference signal of restituted signal light source reference arm and sample arm: the multiplier parameter that utilizes above-mentioned steps (6) changes to the frequency of scale light source on the carrier frequency of signal optical source and generates the two-way orthogonal signalling, utilizes two-way orthogonal signalling restituted signal light source reference arm to be the corresponding reflection envelope signal of each organizational structure of eye with the interference signal of sample arm;
(8) double sampling: the interference crest that utilizes the scale light source changes into positional information with the reflection envelope signal of step (7);
(9) calculate: the interference crest that utilizes the scale light source is as endogenous position scale, utilizes the envelope waveform after the number of the interference waveform of scale light source goes to measure demodulation, calculates the data of each organizational structure of human eye.
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103976707A (en) * | 2014-05-20 | 2014-08-13 | 深圳市斯尔顿科技有限公司 | OCT (Optical Coherence Tomography) system for measuring optical path value of axis oculi and method |
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5042938A (en) * | 1989-05-09 | 1991-08-27 | Kabushiki Kaisha Topcon | Apparatus for measuring length of visual line length, depth of anterior chamber, thickness of crystal lens, etc. |
| WO1992019930A1 (en) * | 1991-04-29 | 1992-11-12 | Massachusetts Institute Of Technology | Method and apparatus for optical imaging and measurement |
| US5347327A (en) * | 1991-04-15 | 1994-09-13 | Kabushiki Kaisha Topcon | Process and apparatus for measuring axial eye length |
| US20070076217A1 (en) * | 2005-10-05 | 2007-04-05 | Chris Baker | Optical coherence tomography for eye-length measurement |
| US20070236661A1 (en) * | 2006-04-07 | 2007-10-11 | Yasufumi Fukuma | Opthalmologic Apparatus |
| JP2007313208A (en) * | 2006-05-29 | 2007-12-06 | Nidek Co Ltd | Intraocular dimension measuring instrument |
| CN101405562A (en) * | 2006-01-19 | 2009-04-08 | 光视有限公司 | A Fourier-domain optical coherence tomography imager |
| US20090147266A1 (en) * | 2007-12-11 | 2009-06-11 | Ming Lai | Eye Length Measurement Apparatus |
| JP2010184050A (en) * | 2009-02-12 | 2010-08-26 | Nidek Co Ltd | Eye size measuring apparatus |
| US20100271594A1 (en) * | 2007-04-13 | 2010-10-28 | Carl Zeiss Meditec Ag | Device and Method for Axial Length Measurement Having Expanded Measuring Function in the Anterior Eye Segment |
-
2012
- 2012-06-19 CN CN201210203312.3A patent/CN102727172B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5042938A (en) * | 1989-05-09 | 1991-08-27 | Kabushiki Kaisha Topcon | Apparatus for measuring length of visual line length, depth of anterior chamber, thickness of crystal lens, etc. |
| US5347327A (en) * | 1991-04-15 | 1994-09-13 | Kabushiki Kaisha Topcon | Process and apparatus for measuring axial eye length |
| WO1992019930A1 (en) * | 1991-04-29 | 1992-11-12 | Massachusetts Institute Of Technology | Method and apparatus for optical imaging and measurement |
| US20070076217A1 (en) * | 2005-10-05 | 2007-04-05 | Chris Baker | Optical coherence tomography for eye-length measurement |
| CN101405562A (en) * | 2006-01-19 | 2009-04-08 | 光视有限公司 | A Fourier-domain optical coherence tomography imager |
| US20070236661A1 (en) * | 2006-04-07 | 2007-10-11 | Yasufumi Fukuma | Opthalmologic Apparatus |
| JP2007313208A (en) * | 2006-05-29 | 2007-12-06 | Nidek Co Ltd | Intraocular dimension measuring instrument |
| US20100271594A1 (en) * | 2007-04-13 | 2010-10-28 | Carl Zeiss Meditec Ag | Device and Method for Axial Length Measurement Having Expanded Measuring Function in the Anterior Eye Segment |
| US20090147266A1 (en) * | 2007-12-11 | 2009-06-11 | Ming Lai | Eye Length Measurement Apparatus |
| JP2010184050A (en) * | 2009-02-12 | 2010-08-26 | Nidek Co Ltd | Eye size measuring apparatus |
Cited By (14)
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|---|---|---|---|---|
| CN103976707A (en) * | 2014-05-20 | 2014-08-13 | 深圳市斯尔顿科技有限公司 | OCT (Optical Coherence Tomography) system for measuring optical path value of axis oculi and method |
| CN103976707B (en) * | 2014-05-20 | 2016-05-04 | 深圳市斯尔顿科技有限公司 | A kind of OCT system and method for measuring axis oculi light path value |
| CN105832285A (en) * | 2015-01-29 | 2016-08-10 | 株式会社多美 | Ophthalmological device |
| CN105588847A (en) * | 2016-01-05 | 2016-05-18 | 佛山科学技术学院 | Great-depth OCT (optical coherence tomograph) scanning device and method for nearly transparent minerals |
| CN105588847B (en) * | 2016-01-05 | 2019-02-26 | 佛山科学技术学院 | A kind of big depth OCT scan device and method for near-transparent minerals |
| CN108498067A (en) * | 2018-04-19 | 2018-09-07 | 长春理工大学 | A kind of device and method of digitlization keratometry |
| CN110169752A (en) * | 2019-06-13 | 2019-08-27 | 长春理工大学 | A kind of optical fiber type eyeball axial direction multi-parameter Fast measurement system |
| CN110169752B (en) * | 2019-06-13 | 2021-12-17 | 长春理工大学 | Optical fiber type eyeball axial multi-parameter rapid measurement system |
| CN113440099A (en) * | 2021-06-07 | 2021-09-28 | 天津市索维电子技术有限公司 | Human eye vision comprehensive inspection device and method |
| CN113397476A (en) * | 2021-06-16 | 2021-09-17 | 浙大宁波理工学院 | Method for full-automatic measurement of eyeball parameters |
| CN113397476B (en) * | 2021-06-16 | 2023-08-22 | 浙大宁波理工学院 | Method for fully automatically measuring eyeball parameters |
| CN113791492A (en) * | 2021-07-26 | 2021-12-14 | 中国科学院重庆绿色智能技术研究院 | Novel optical delay line |
| CN114366019A (en) * | 2022-01-27 | 2022-04-19 | 长春理工大学 | System and method for measuring eyeball parameters |
| CN114366019B (en) * | 2022-01-27 | 2023-02-24 | 长春理工大学 | System and method for measuring eyeball parameters |
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