All-in-one eyeball comprehensive parameter measuring instrument and method for measuring eyeball parameters by using same

Abstract

The invention discloses an all-in-one eyeball comprehensive parameter measuring instrument and a method for measuring eyeball parameters by using the same. The measuring instrument comprises a signal light source, a signal light source sample arm, a signal light source reference arm, a scale light source, a scale light source sample arm, a scale light source reference arm, an annular light source, a telecentric lens, a zoom lens group and the like, the instrument can measure biological parameter information of human eyes, corneal curvature and eyeball diopter at the same time. The device is scientific and reasonable in design, and has the advantage that the curvature, the diopter and the biological parameters of the human eyes can be simultaneously measured at one time under the non-contact and non-invasive conditions.

Description

Technical Field

[0001] The present application relates to the field of optical measurement technology, and in particular to an all-in-one eyeball comprehensive parameter measuring instrument and a method for measuring eyeball parameters using the same. Background Art

[0002] With the development of ophthalmic technology, the prevention and treatment of eye diseases have been greatly expanded, such as laser surgery to correct myopia, cataract removal combined with intraocular artificial lens implantation to treat cataracts, corneal refractive surgery to treat myopia, hyperopia, astigmatism, etc. Eye biometry technology is also increasingly valued by clinicians.

[0003] Eyeball biometry is the measurement of eyeball structural parameters using various related inspection methods, such as corneal thickness, anterior chamber depth, lens thickness, vitreous cavity length, and eyeball axial length, including corneal curvature and eyeball refractive power detection, to provide a basis for the diagnosis and treatment of eye diseases. How to obtain accurate parameters of each component of the eyeball has always been the direction of research. Any slight error can prevent a perfect operation from achieving the desired effect.

[0004] Currently, the commonly used biometric measuring instrument for eyeball length is ultrasonic measurement, such as A-ultrasound. Its principle is to transmit ultrasonic waves through the human eye and reflect them at the interface of various tissues, and use the amplitude of the echo pulse to determine the position information of each tissue.

[0005] The above-mentioned traditional ultrasonic A-ultrasound measurement has problems such as contact with the cornea during measurement (cross-infection), uncertain alignment (affected by the operator's technique), compression of the anterior chamber, and low accuracy for specific eyes (high myopia, posterior scleral staphyloma, and deformation of the posterior wall of the eyeball).

[0006] In clinical practice, the most commonly used ophthalmometer for eye examination is to check the refractive power of the human eye, but the ophthalmometer cannot prevent the occurrence of myopia and has limited effect on the prevention and control of myopia in adolescents. With the development of medicine, researchers have found that tracking the changes in the ratio of axial length to corneal curvature and refractive power compensation can predict the risk of myopia in adolescents to a certain extent. The measurement equipment of these biological parameters has become a research hotspot and development trend in this field.

[0007] In recent years, there have been instruments that use OCT technology to measure biological eye parameter information. For example, instruments using partial coherence interferometer (PCI) and low coherence reflectometry (LCR) have the advantages of non-contact measurement, high measurement accuracy (10um, ultrasound 100um), and automatic alignment compared to traditional ultrasound A-ultrasound. However, the functions of the above-mentioned measuring instruments are often relatively single. With the maturity of optical measurement technology, the need for technological innovation provides a development direction for equipment that can integrate more technologies, have more complete functions, and are more intelligent and automated. A comprehensive system that can measure multiple eye parameters with complete functions, compact structure, and accurate measurement has become a development trend. However, the multifunctional eye parameter measurement system has put forward higher requirements for design and use. The integration of multifunctional and multi-modules needs to consider the integration and compatibility of more technologies. At the same time, the calibration and maintenance of the equipment are more complicated and time-consuming. In order to ensure accuracy and reliability, the close coordination of software and hardware requires more careful design and debugging. In addition, precision instruments also increase the complexity and difficulty of operation for operators. Summary of the invention

[0008] The purpose of the present invention is to provide an all-in-one eye comprehensive parameter measuring instrument and a method for measuring eye parameters using the same, so as to solve the problems of single functional structure and low integration of current equipment. The curvature, refractive power and biological parameters of the human eye can be measured at one time under non-contact and non-invasive conditions, so as to achieve a more intelligent and practical purpose.

[0009] In order to achieve the above object, the present invention adopts the following technical solution: In a first aspect, an all-in-one eyeball comprehensive parameter measuring instrument is provided, comprising a signal light source module, a scale light source module, a dichroic mirror, a wavelength division multiplexer, an optical delay line, a ring light source, an illumination imaging module, a sight mark illumination module, a sight mark imaging module, a second spectroscope, a third spectroscope, a data acquisition card, and a data processing unit; The signal light source module emits two beams of light, one of which is transmitted to the dichroic mirror, and after being reflected by the dichroic mirror, enters the eyeball to be tested, and after being reflected by the eyeball, the return light returns to the signal light source module along the original path; the other light enters the wavelength division multiplexer, is transmitted to the optical delay line, and after being reflected by the optical delay line, the return light returns to the signal light source module along the original path, and the two return lights interfere in the signal light source module; The ruler light source module emits two beams of light, one of which returns to the ruler light source module along the original path after being reflected, and the other enters the wavelength division multiplexer, is transmitted to the optical delay line, and returns to the ruler light source module along the original path after being reflected by the optical delay line, and the two returning lights interfere in the ruler light source module; The light emitted by the annular light source is reflected by the cornea to be measured, and the reflected light is transmitted through the dichroic mirror and the second beam splitter, and then enters the illumination imaging module for annular light source imaging; the sight mark illumination module illuminates the sight mark image, and after passing through the third beam splitter and the second beam splitter, the sight mark image of the fundus is imaged on the fundus, and the sight mark image of the fundus is transmitted to the sight mark imaging module for clear imaging; The signal light source module and the scale light source module are both connected to the data acquisition card, the data acquisition card is connected to the data processing unit, and the data processing unit is connected to the optical delay line.

[0010] Optionally, the signal light source module includes a signal light source, an optical fiber circulator, a photoelectric balance detector, a first optical fiber coupler, a signal light source sample arm, and a signal light source reference arm; The signal light source emits light that passes through the fiber optic circulator and enters the first fiber optic coupler from the fiber optic circulator. The first fiber optic coupler divides the light into two beams that enter the signal light source sample arm and the signal light source reference arm respectively. The light from the signal light source sample arm is deflected in the optical path by a dichroic mirror and then transmitted to the measurement eyeball reflection, and the returned light re-enters the third port of the first fiber optic coupler. The signal light source reference arm is connected to a wavelength division multiplexer and an optical delay line. The light from the signal light source reference arm is reflected by the optical delay line and the returned light re-enters the fourth port of the first fiber optic coupler. The two return lights that enter the first fiber optic coupler interfere and are respectively input into the fiber optic circulator and the photoelectric balanced detector from the first port and the second port of the first fiber optic coupler. The fiber optic circulator is connected to the photoelectric balanced detector, and the photoelectric balanced detector amplifies the two differentials, converts them into electrical signals, and transmits them to the data acquisition card.

[0011] Optionally, the signal light source sample arm includes a first optical fiber collimator, a first spectroscope, a signal light source test arm, a signal light source zero point arm and a first polarization controller; the signal light source reference arm is provided with a second polarization controller; The light from the signal light source sample arm passes through the first optical fiber collimator and enters the first beam splitter, and is divided into two beams of light that respectively enter the signal light source test arm and the signal light source zero point arm. The signal light source test arm and the signal light source zero point arm can reflect the light, and the returned photosynthetic beam re-enters the third port of the first optical fiber coupler; The first polarization controller is used to control the polarization state of the light returned from the sample arm of the signal light source, and the second polarization controller is used to control the polarization state of the light returned from the reference arm of the signal light source.

[0012] Optionally, the scale light source module includes a scale light source, a photoelectric unit detector, a second optical fiber coupler, a scale light source sample arm, a scale light source reference arm and an optical fiber reflector; The light emitted by the scale light source is divided into two beams by the second optical fiber coupler, and enters the scale light source sample arm and the scale light source reference arm respectively. The scale light source sample arm is connected to the optical fiber reflector. After the light is reflected by the optical fiber reflector, the returned light enters the third port of the second optical fiber coupler. The light of the scale light source reference arm is transmitted from the wavelength division multiplexer to the optical delay line. After the light is reflected by the optical delay line, the returned light enters the fourth port of the second optical fiber coupler. The two return lights entering the second optical fiber coupler interfere with each other and come out from the first port and the second port of the second optical fiber coupler respectively, and then are respectively input into the scale light source and the photoelectric unit detector. The photoelectric unit detector converts the optical signal into an electrical signal, and then transmits it to the data acquisition card.

[0013] Optionally, the optical delay line includes a second fiber optic collimator, a voice coil motor, a right-angle prism, a hollow roof prism, a fifth plane reflector, a sixth plane reflector and a cemented lens, wherein the hollow roof prism is installed in front of the voice coil motor, the right-angle prism is fixedly installed in front of the hollow ridge surface of the hollow roof prism, the fifth plane reflector and the sixth plane reflector are installed on the left and right sides of the right-angle prism, and the sixth plane reflector is installed in front of the cemented lens; after the light is collimated by the second fiber optic collimator, it is transmitted to the fifth reflector, and after the light path is deflected, it is transmitted back and forth between the right-angle prism and the hollow roof prism, and then it is converged by the cemented lens and focused and reflected at the sixth reflector, and the light path is transmitted along the original path and then re-coupled into the second fiber optic collimator.

[0014] Optionally, the lighting imaging module includes a telecentric lens and a first camera; The light emitted by the annular light source is reflected by the cornea, and the reflected light is imaged by the first camera after passing through the dichroic mirror, the second beam splitter and the telecentric lens.

[0015] Optionally, the sight mark lighting module includes a sight mark light source, a sight mark, a first lens, a reflector and a second lens; The sight mark light source illuminates the sight mark, and the illumination light is focused by the first lens, then deflected by the reflector, and then focused into parallel light by the second lens; then, after being transmitted by the third beam splitter and reflected by the second beam splitter, it is transmitted by the dichroic mirror and finally imaged on the retina.

[0016] Optionally, the sight mark imaging module includes a zoom lens group and a second camera; The sight mark image returns along the original path after being reflected, is transmitted through the dichroic mirror, enters the zoom lens group after being reflected by the second beam splitter and the third beam splitter, and is finally imaged by the second camera.

[0017] Optionally, a movable lens is provided on the zoom lens group, and the focal length of the system is changed by the movable lens so that the second camera can form a clear image. The refractive power of the eyeball can be measured by adjusting the position of the movable lens on the zoom lens group.

[0018] In a second aspect, a measurement method using the all-in-one eyeball comprehensive parameter measuring instrument according to the first aspect is provided, the method comprising the following steps: Step S1: adjusting the distance between the annular light source and the model cornea to make the image on the illumination imaging module clear, and calculating the center of mass and the inner and outer ring diameters to obtain the corneal curvature; Step S2: adjusting the sight mark imaging module so that the image on it is clear, thereby obtaining the eyeball diopter; Step S3: dynamically adjust the distance between the annular light source and the cornea so that the illumination imaging module forms a clear image, adjust the detection light to be incident on the eyeball, and also adjust the optical path from the signal light source module to the cornea. The data acquisition card dynamically acquires the interference signal measurement data of the signal light source module. Step S4: performing mean subtraction, bandpass, and smoothing filtering on the interference signal measurement data, and then calculating the cross-correlation to obtain a signal waveform with a prominent peak signal; Step S5: Use the processed signal waveform to search for peak values, find the signal peak value and obtain position information; Step S6: synchronously acquiring the interference peak of the scale light source module closest to the position information obtained in step S5 by using the scale light source module and the signal light source module to share the same optical delay line; Step S7: using the interference peak of the ruler light source module as an endogenous position ruler, using the number of interference waveforms of the ruler light source module to calculate the corresponding peak position information interval distance obtained in step S6, and calculating the data of each tissue structure of the human eye.

[0019] The beneficial effects of the present invention are as follows: The present invention combines an all-in-one eyeball comprehensive parameter measuring instrument, adopts low-coherence light measurement technology and imaging technology, and designs modules such as a signal light source module, a ruler light source module, an illumination imaging module, a sight mark illumination module, a sight mark imaging module, and an optical delay line. The signal light source module is used to measure eyeball biological parameters, the ruler light source module is used to calculate the eyeball biological parameter distance, the annular light source and the telecentric lens in the illumination imaging module can measure the corneal curvature through the imaging of the annular light source, and the refractive compensation of the zoom lens group of the sight mark imaging module can measure the eyeball refractive power. Through the reasonable spatial layout of multiple devices, multiple functions can be measured simultaneously, which overcomes the problems of single function and low integration of current equipment, and has high measurement accuracy and obvious measurement effect.

[0020] The present invention uses a method for measuring eyeball parameters using an all-in-one eyeball comprehensive parameter measuring instrument. The method comprises the following steps: firstly starting the measuring instrument to light up each light source and starting a voice coil motor, then sequentially performing illumination board light source imaging and fundus sight mark imaging to obtain eyeball diopter, then dynamically obtaining interference waves, accurately determining the distance between the annular light source and the cornea, then demodulating the signal light source interference signal, searching for peaks to obtain position information, synchronously obtaining the scale light source interference wave peak, and finally calculating each tissue structure data of the human eye using scale light source related information. The processing of low signal-to-noise ratio signals is performed by performing bandpass filtering on the signals, then performing mean flipping, and then performing mean smoothing filtering algorithm processing. By performing cross-correlation algorithm comparison on each measurement result, measurement data with cross-correlation results greater than a set threshold are retained. The method can effectively remove noise caused by mechanical vibration and white noise of the signal channel, especially irregular changes in signal height introduced by eyeball movement.

[0021] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0023] Figure 1 It is a schematic diagram of the overall structure of an all-in-one eyeball comprehensive parameter measuring instrument provided by an embodiment of the present invention.

[0024] Figure 2 It is a schematic diagram of the structure of an optical delay line provided by an embodiment of the present invention.

[0025] Figure 3 It is a schematic structural diagram of a zoom lens assembly provided by an embodiment of the present invention.

[0026] Figure 4 It is a signal processing flow chart provided by an embodiment of the present invention.

[0027] Figure 5 It is a processing flow chart of the mean smoothing filtering algorithm provided by an embodiment of the present invention.

[0028] Figure 6 It is a peak search process flow chart provided by an embodiment of the present invention.

[0029] Figure 7 It is the signal data to be processed provided by the embodiment of the present invention.

[0030] Figure 8 It is the processed signal data provided by the embodiment of the present invention.

[0031] In the figure: 1, signal light source; 2, fiber circulator; 3, photoelectric balanced detector; 4, first fiber coupler; 5, first polarization controller; 6, second polarization controller; 7, first fiber collimator; 8, first beam splitter; 9, first reflector; 10, second reflector; 11, glass rod; 12, first plano-convex lens; 13, third reflector; 14, second plano-convex lens; 15, first camera; 16, telecentric lens; 17, second beam splitter; 18, dichroic mirror; 19, ring light source; 20, model eye; 21, second camera; 22, zoom lens group; 23, third beam splitter; 24, sight mark light source; 25, sight mark; 26, first Positive lens; 27. fourth reflector; 28. second positive lens; 29. ​​wavelength division multiplexer; 30. data processing unit; 31. scale light source; 32. photoelectric unit detector; 33. second fiber optic coupler; 34. fiber optic reflector; 35. optical delay line; 36. data acquisition card; 37. second fiber optic collimator; 38. fifth reflector; 39. voice coil motor; 40. hollow roof prism; 41. right-angle prism; 42. cemented lens; 43. sixth reflector; 44. movable lens; 45. fixed lens, 46 signal light source module, 47 lighting imaging module, 48 sight mark imaging module, 49 sight mark lighting module, 50 scale light source module. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. It should be emphasized that the implementation examples described in the present invention are illustrative rather than restrictive, and therefore the present invention is not limited to the implementation examples described in the specific implementation methods.

[0033] refer to Figure 1-Figure 3 The embodiment of the present invention provides an all-in-one eyeball comprehensive parameter measuring instrument, including a signal light source module 46, a scale light source module 50, a dichroic mirror 18, a wavelength division multiplexer 29, an optical delay line 35, a ring light source 19, an illumination imaging module 47, a sight mark imaging module 48, a sight mark illumination module 49, a second beam splitter 17, a third beam splitter 23, a data acquisition card 36 and a data processing unit 30; In one embodiment, the signal light source module 46 includes a signal light source 1, an optical fiber circulator 2, a photoelectric balanced detector 3, a first optical fiber coupler 4, a signal light source sample arm and a signal light source reference arm. The signal light source sample arm includes a first optical fiber collimator 7, a first beam splitter 8, a signal light source test arm, a signal light source zero point arm and a first polarization controller 5; the signal light source reference arm is provided with a second polarization controller 6; the signal light source test arm includes a first reflector 9 and a second plano-convex lens 14; the signal light source zero point arm includes a second reflector 10, a first plano-convex lens 12, a glass rod 11, and a third reflector 13. The signal light source test arm is designed to quickly measure human eye information, and the signal light source zero point arm is used to measure position positioning.

[0034] In one embodiment, the signal light source 1 is connected to the first port of the optical fiber circulator 2, the second port of the optical fiber circulator 2 is connected to the first port of the first optical fiber coupler 4, the third port of the optical fiber circulator 2 is connected to the first signal input port of the photoelectric balance detector 3, and the second signal input port of the photoelectric balance detector 3 is connected to the second port of the first optical fiber coupler 4. The light emitted by the signal light source 1 passes through the optical fiber circulator 2 and is divided into two beams of light by the first optical fiber coupler 4, and enters the signal light source sample arm and the signal light source reference arm respectively; the light of the signal light source sample arm is transmitted from the optical fiber outlet, is collimated by the first optical fiber collimator 7, and is transmitted to the first beam splitter 8 for 5:5 light intensity equalization, one path of the light is reflected into the signal light zero point arm, and the other path is transmitted into the signal light source test arm. After the light entering the signal light source test arm passes through the first reflector 9 and the second plano-convex lens focusing 14, it is deflected by the dichroic mirror 18, and then transmitted to the measuring eyeball reflection, and the return light is transmitted along the original path to enter the third port of the first optical fiber coupler 4; after the light entering the signal light source zero point arm is reflected by the third reflector, the first plano-convex lens 13 converges the light so that it enters the glass rod 11 completely for transmission, and then reflects at the second reflector 10, and the reflected light is transmitted along the original path to enter the third port of the first optical fiber coupler 4. The signal light source reference arm is connected to the wavelength division multiplexer 29 and the optical delay line 35. The light transmission of the signal light source reference arm is transmitted from the wavelength division multiplexer 29 to the optical delay line 35. After being reflected by the optical delay line 35, the return light re-enters the fourth port of the first optical fiber coupler 4. After the two return lights entering the first optical fiber coupler 4 interfere, they are respectively input from the first port and the second port of the first optical fiber coupler 4 to the second port of the optical fiber circulator 2 and the second port of the photoelectric balance detector 3.

[0035] In one embodiment, the signal light source reference arm is provided with a second polarization controller 6; the second polarization controller 6 is used to control the polarization state of the return light of the signal light source reference arm, and by adjusting the polarization state of the signal light source reference arm, the signal light source reference arm and the signal light source sample arm are in the same light polarization state. At this time, the interference signal contrast is the highest and the signal intensity is the highest; the first polarization controller 5 is used to control the polarization state of the return light of the signal light source sample arm, and the second polarization controller 6 is used to control the polarization state of the return light of the signal light source reference arm.

[0036] After polarization control, the light interference between the sample arm of the signal light source and the reference arm of the signal light source will be input from the second port of the optical fiber circulator 2 to the third port of the optical fiber circulator 2, and then input to the first port of the photoelectric balance detector 3; the photoelectric balance detector 3 receives the interference light from the sample arm of the signal light source and the reference arm of the signal light source, and sends it to the data acquisition card 36, and the acquisition card then sends the data to the data processing unit 30.

[0037] In one embodiment, the scale light source module 50 includes a scale light source 31, a photoelectric unit detector 32, a second fiber coupler 33, a scale light source sample arm, a scale light source reference arm, and a fiber reflector 34; The scale light source 31 is connected to the first port of the second fiber coupler 33, and the second port of the second fiber coupler 33 is connected to the photoelectric unit detector 32. The light emitted by the scale light source 31 is divided into two beams of light by the second fiber coupler 33, and enters the scale light source sample arm and the scale light source reference arm respectively. The scale light source sample arm is connected to the fiber reflector 34. The fiber reflector 34 is used for the scale light source sample arm to reflect the light back to the original path. The fiber reflector 34 can reflect the light with maximum efficiency for interference without spatial optical coupling. After the light is reflected by the fiber reflector 34, the returned light enters the third port of the second fiber coupler 33, and the light of the scale light source reference arm is transmitted from the wavelength division multiplexer 29 to the optical delay line 35. After being reflected by the optical delay line 35, the returned light enters the fourth port of the second fiber coupler 33. After the two return lights entering the second fiber coupler 33 interfere, they come out from the first port and the second port of the second fiber coupler 33 respectively, and are then input into the scale light source 31 and the photoelectric unit detector 32 respectively; the photoelectric unit detector 32 receives the interference light from the scale light source sample arm and the scale light source reference arm, and sends it to the data acquisition card 36, and the data acquisition card 36 then sends the data to the data processing unit 30 for data processing and display.

[0038] The photoelectric balance detector 3 and the photoelectric unit detector 32 are both connected to the data acquisition card 36, the data acquisition card 36 is connected to the data processing unit 30, and the data processing unit 30 is connected to the optical delay line 35. In one embodiment, the optical delay line 35 includes a second fiber collimator 37, a voice coil motor 39, a right-angle prism 41, a hollow roof prism 40, a fifth plane reflector 38, a sixth plane reflector 43 and a cemented lens 42, the hollow roof prism 40 is installed in front of the voice coil motor 39, the right-angle prism 41 is fixedly installed in front of the hollow roof surface of the hollow roof prism 40, the fifth plane reflector and the sixth plane reflector are installed on the left and right sides of the right-angle prism 41, and the cemented lens 42 is installed in front of the sixth plane reflector; after the light is collimated by the second fiber collimator 37, it is transmitted to the fifth reflector 38, and the light path is deflected and then passes through the right-angle prism. The light is transmitted back and forth between the hollow roof prism 41 and the hollow roof prism 40, and then converged by the glued lens 42 and focused and reflected by the sixth reflector 43. After the light path is transmitted along the original path, it is re-coupled into the second fiber collimator 37. Among them, the deflection of the light path by the hollow roof prism 40 and the right-angle prism 41 can significantly improve the measurement range under the premise of the limited movement distance of the voice coil motor 39. The glued lens 42 is used to focus the light beam at the reflector, which can effectively reduce the problem of reduced spatial light coupling efficiency caused by the angular offset of the reflector position. At the same time, the glued lens 42 can eliminate the chromatic aberration introduced by the two wavelengths of the signal light source 1 and the scale light source 31 when they are transmitted in the optical delay line 35.

[0039] In one embodiment, the illumination imaging module includes a telecentric lens 16 and a first camera 15, the annular light source 19 emits light to illuminate the eyeball, the light reflected from the cornea of ​​the eyeball passes through the hollow part of the annular light source 19, the light is transmitted through the dichroic mirror 18 and the second beam splitter 17, and after passing through the telecentric lens 16, an image is formed on the first camera 15. The positions of the annular light source 19 and the signal light source sample arm, the signal light source reference arm, the scale light source sample arm, and the scale light source reference arm are relatively fixed, and at this moment, the positions meet the optical path conditions required for the signal light source sample arm and the reference arm, and the scale light source sample arm and the reference arm to form a stable interference wave, and the distance conditions for forming a clear image with the first camera 15, and the position of the measured eye relative to the measuring instrument is adjusted by observing the camera, and when a clear image is observed, it indicates that the measured eye is within the measuring range of the measuring instrument at this time.

[0040] The sight mark lighting module includes a sight mark light source 24, a sight mark 25, a first lens 26, a fourth reflector 27 and a second lens 25; the sight mark imaging module includes a zoom lens group 22 and a second camera 21; in one embodiment, the first lens 26, the fourth reflector 27 and the second lens 25 are arranged in sequence between the sight mark 25 and the third beam splitter 23; the illumination light passes through a 4f system composed of a first positive lens 26, a fourth reflector 27 and a second positive lens 28, transmits through the third beam splitter 23, is reflected at the second beam splitter 17, and after transmitting through a dichroic mirror 18, forms a sight mark image on the retina. The sight mark image is used as an object, passes through the dichroic mirror 18 and the second beam splitter 17, is reflected by the third beam splitter 23 and enters the zoom lens group 22. The first lens of the zoom lens group 22 is a fixed lens 45, and the second lens is a movable lens 44. By moving the movable lens 44, the light passes through the zoom lens group 22 and forms a clear image on the second camera 21. The fourth reflector 27 is used to deflect the light path, and the first lens 26 and the second lens 25 are used to extend the light path to the maximum extent while ensuring the parallelism of the light path.

[0041] In one embodiment, a movable lens 44 is provided on the zoom lens group 22, and the focal length of the system is changed by the movable lens 44 so that the second camera 21 can form a clear image, wherein the position of the movable lens 44 on the zoom lens group 22 corresponds to the diopter compensation value of the zoom lens group 22 one by one, and the diopter compensation value of the system can be measured by moving the position of the lens 44 to measure the diopter of the human eye.

[0042] As can be seen from the above embodiments, the present application designs an integrated all-in-one eyeball comprehensive parameter measuring instrument, including a signal light source module for measuring biological parameters of the human eye, a ruler light source module for synchronously calculating the size of biological parameter information of the human eye, an optical path where the ring light source 19 is located is used to measure corneal curvature, and an optical path where the sight mark light source 24 and the zoom lens group 22 are located is used to measure the refractive power of the eyeball. The embodiment of the present invention also provides a method for measuring eyeball parameters using the above all-in-one eyeball comprehensive parameter measuring instrument, the method comprising the following steps: Step S1: Illumination board light source imaging: adjust the distance between the annular light source and the model cornea to make the image on the illumination imaging module clear, and calculate the corneal curvature by calculating the centroid and the inner and outer ring diameters; Specifically, the measuring instrument is moved, and the distance between the annular light source 19 and the model cornea is adjusted to make the image on the illumination imaging module 47 clear, and the corneal curvature can be obtained by calculating the centroid and the inner and outer ring diameters; In the present invention, the first camera on the illumination imaging module displays a ring image, which can be obtained by using the centroid algorithm formula: ; in, , is the pixel coordinate, The center of mass of the ring is calculated based on the pixel light intensity. The inner and outer diameters of the ring can be calculated based on the coordinate points of the ring light intensity. The diameter can be used to calculate the corneal curvature radius, corneal transverse diameter and pupil diameter.

[0043] Step S2: fundus sight mark imaging: adjusting the sight mark imaging module to make the image on it clear, and then obtaining the eyeball diopter; this step may include the following sub-steps: Step S21: calibrating the refractive states of the movable lens of the zoom lens assembly of the sight mark imaging module at different positions; Step S22: moving the movable lens of the zoom lens group to change the focal length of the zoom lens group and perform refractive compensation on the retinal image; Step S23: Observe the image clarity of the second camera on the sight mark imaging module during the process of moving the lens, and record the position of the movable lens when the image is the clearest; Step S24: querying the lens position and diopter correspondence table to obtain the eyeball diopter; In the present invention, the diopter of an optical system can be calculated using the formula: in, is the object distance, is the image distance, is the focal length, according to the definition of optical focal length: Where: is the incident light focal length; Since the human eye is defined by the incident light, the optical power is The outgoing light corresponds to Eyeballs; Where: is the optical power of the outgoing light; From the above formula, we can get: The theoretical diopter calculation formula is the difference between focal length and object distance divided by the product of focal length and object distance; By moving the movable lens of the zoom lens group, it can be known that the refractive power of the eyeball can be calculated by making the refractive power of the sight mark imaging module complementary to the refractive power of the eyeball.

[0044] Step S3: Dynamically obtain interference waves: dynamically adjust the distance between the annular light source and the cornea to make the illumination imaging module form a clear image, adjust the detection light to be incident on the eyeball, and also adjust the optical path from the signal light source module to the cornea. The data acquisition card dynamically obtains the interference signal measurement data of the signal light source module; Specifically, the distance between the annular light source 19 and the cornea is dynamically adjusted to make the first camera form a clear image, the detection light is adjusted to be incident on the eyeball, and the optical path from the signal light source module to the cornea is also adjusted, and the data acquisition card dynamically obtains the interference signal measurement data of the signal light source module; In the present invention, the positions of the annular light source 19 and the signal light source sample arm, the signal light source reference arm, the scale light source sample arm and the scale light source reference arm are relatively fixed. At this moment, the positions satisfy the optical path conditions required for the signal light source sample arm and the reference arm, the scale light source sample arm and the reference arm to form a stable interference wave and the distance conditions for a clear image of the first camera. The interference signal waveform includes the waveform on the signal light source test arm, the waveform of the signal light source zero point arm and the interference waveform of the scale light source sample arm and the scale light source reference arm. Step S4: performing mean subtraction, bandpass, and smoothing filtering on the interference signal measurement data, and then calculating the cross-correlation to obtain a signal waveform with a prominent peak signal; Specifically, the measurement data obtained in step S3 is first subjected to mean subtraction flipping processing, and then subjected to bandpass and smoothing mean filtering to obtain a zero-point signal and a peak signal waveform for measuring eye parameters, and then subjected to low-pass filtering to obtain a signal waveform with a prominent peak signal; each measurement result is cross-correlated, and the signal with the largest cross-correlation result is retained for superposition to further remove noise signals; In the present invention, the optical delay line 35 used in the system is a linear motion driven by a voice coil motor 39. Since the voice coil motor 39 vibrates back and forth, it will introduce mechanical noise, resulting in a decrease in the signal-to-noise ratio. Based on this situation, the present invention designs a smoothing filter algorithm to process the low signal-to-noise ratio introduced by excessive vibration. The filtering algorithm flow is referenced to Figure 4 Specifically, for the collected interference signal, first calculate the average value and get Since the original data has both positive and negative values, in order to achieve the flip of negative data, the original data and By making a difference and then finding the absolute value, the negative data can be flipped upward relative to the average value.

[0045] In order to find the peak value corresponding to zero optical path difference and extract the useful signal, the above interference signal is smoothed and filtered. The processing method is as follows: Figure 5 As shown. First, set an appropriate filtering mean window K. The larger the K value, the higher the signal smoothness, but the lower the sensitivity and the slower the operation speed; the smaller the n value, the lower the signal smoothness, but the lower the sensitivity and the faster the operation speed. For the convenience of calculation, n is generally an integer power of 2, such as 4, 8, 16, 32, etc. Then calculate the average of the flipped values ​​and the average of adjacent values ​​within a certain range. Take each average as the new filtered result.

[0046] Taking into account that the measured sample is a biological eyeball, it is inevitable that the biological eyeball will move during the measurement process, resulting in missing layers of the measured biological eyeball. Therefore, the present invention designs a cross-correlation algorithm to perform data segmentation comparison, retaining the data segments whose cross-correlation results are greater than the set threshold, and by processing multiple measurement results, the complete sample information can be calculated.

[0047] Calculate the correlation coefficient of the corresponding position of each range data segment, and the calculation formula is: ; in, is the sample standard deviation of X, and the formula is: , ; is the sample covariance, and the formula is: ; sample , Represents the data of two adjacent scanning ranges. Represents the sample mean of the scanned data, and n is the sample data size.

[0048] Step S5: Peak search and acquisition: Use the processed signal waveform to search for the peak value, find the signal peak value and obtain the position information; Specifically, refer to Figure 6 In this example, for the filtered value, the signal extreme value can be obtained by taking the first-order derivative of the signal, and then the second-order derivative can be used to determine whether the extreme value is a maximum value. Considering that the filtered signal cannot be completely smooth, the minimum interval between peaks, the height threshold and the peak reference height are added here to make the peak value more reasonable.

[0049] The present invention realizes real-time synchronization between data acquisition and the boundary of linear motion. Since linear motion is not unidirectional, the voice coil motor 39 will move back and forth, so the scanning range of the signal sample arm of the corresponding biological eye test system is also a back and forth scan. The present invention uses the boundary of the linear motion of the voice coil motor 39 as the starting point of the scanning range. When the voice coil motor 39 reaches the boundary, the hardware triggers the signal acquisition card to collect signals. When scanning a complete range, the voice coil motor 39 moves to the other end boundary. At this time, the data acquisition card 36 receives the boundary signal and synchronously collects the signal of the next range.

[0050] Step S6: synchronous information acquisition: synchronously acquiring the interference peak of the scale light source module closest to the corresponding position in step S5 by using the scale light source module 50 and the signal light source module 46 to share the same optical delay line; Step S7: Calculation: using the interference wave peak of the ruler light source module as an endogenous position ruler, using the number of interference waveforms of the ruler light source module to calculate the corresponding peak position information interval distance obtained in step S6, and calculating the data of each tissue structure of the human eye; Specifically, the interference wave peak of the ruler light source module 50 is used as an endogenous position ruler, and the number of interference waveforms of the ruler light source module 50 is used to calculate the corresponding peak position information interval distance obtained in step S6, and the data of each tissue structure of the human eye is calculated. The signal waveform diagram of each tissue of the human eye can also be displayed in real time on the data processing unit, and the peak distance information can be displayed at the same time.

[0051] Examples: like Figure 1 As shown, the signal light source 1 adopts a superluminescent diode with a selected central wavelength of 840nm, a bandwidth of 40nm, and an optical power of 6mw, and the scale light source 31 adopts a DFB (Distributed Feed Back) laser with a central wavelength of 1310nm, a bandwidth of 1GH, and an optical power of 10mw; The first optical fiber coupler 4 is a 2*2 optical fiber device whose central wavelength and bandwidth match those of the signal light source, and the optical fiber is a single-mode optical fiber. The second optical fiber coupler 33 is a 2*2 optical fiber device whose central wavelength and bandwidth match those of the scale light source, and the optical fiber is a single-mode optical fiber. The first fiber collimator 7 and the second fiber collimator 37 are aspheric lenses with a central wavelength of 840 nm and a focal length of 11 mm; The focal length of the first plano-convex lens 12 is 50 mm, and the focal length of the second plano-convex lens 14 is 100 mm; the focal length of the first positive lens 26 is 50 mm, the focal length of the second positive lens 28 is 30 mm, the focal length of the fixed lens 45 is 20 mm, and the focal length of the movable lens 44 is 30 mm; The first polarization controller 5 and the second polarization controller 6 change the polarization state of the light by mechanically twisting and stretching the optical fiber; The photoelectric balance detector 3 and the photoelectric unit detector 32 are photoelectric devices that can convert optical signals into electrical signals; The wavelength division multiplexer 29 can transmit the light with a central wavelength of 840nm and reflect the light with a central wavelength of 1310nm; The first beam splitter prism splits the central 840nm light by 5:5; the second and third beam splitters split the 940nm light by 5:5; The ring light source and vision light source LED are 940nm near-infrared light sources, and the first camera is CCD or CMOS; The model eye 20 was measured using the system of the present invention, and the results are as follows: Figure 7 and Figure 8 As shown, Figure 7Represents the data collected by the detector. Figure 8 It represents the result of signal processing using the design of the present invention, wherein a is the interference peak of the anterior surface of the cornea, b is the interference peak of the posterior surface of the cornea, c is the interference peak of the anterior surface of the lens, d is the interference peak of the posterior surface of the lens, and e is the interference peak of the retina. According to the position of each peak, all biological parameters of the eyeball can be accurately calculated at one time, including corneal thickness, anterior chamber depth, lens thickness, vitreous thickness, and axial length.

[0052] The technical solution of the present invention is described in detail above in conjunction with the accompanying drawings, and the described embodiments are used to help understand the concept of the present invention. The specific embodiments described herein are merely examples of the present invention. Those skilled in the art of the invention may make various modifications or supplements to the described specific embodiments or replace them in a similar manner, but they will not deviate from the spirit of the present invention or exceed the scope defined by the attached claims.

Claims

1. An all-in-one eyeball comprehensive parameter measuring instrument, comprising a signal light source module, a scale light source module, a dichroic mirror, a wavelength division multiplexer, an optical delay line, a ring light source, an illumination imaging module, a sight mark illumination module, a sight mark imaging module, a second spectroscope, a third spectroscope, a data acquisition card and a data processing unit; The signal light source module emits two beams of light, one of which is transmitted to the dichroic mirror, and after being reflected by the dichroic mirror, enters the eyeball to be tested, and after being reflected by the eyeball, the return light returns to the signal light source module along the original path; the other light enters the wavelength division multiplexer, is transmitted to the optical delay line, and after being reflected by the optical delay line, the return light returns to the signal light source module along the original path, and the two return lights interfere in the signal light source module; The ruler light source module emits two beams of light, one of which returns to the ruler light source module along the original path after being reflected, and the other enters the wavelength division multiplexer, is transmitted to the optical delay line, and returns to the ruler light source module along the original path after being reflected by the optical delay line, and the two returning lights interfere in the ruler light source module; The light emitted by the annular light source is reflected by the cornea to be measured, and the reflected light is transmitted through the dichroic mirror and the second beam splitter, and then enters the illumination imaging module for annular light source imaging; the sight mark illumination module illuminates the sight mark image, and after passing through the third beam splitter and the second beam splitter, the sight mark image of the fundus is imaged on the fundus, and the sight mark image of the fundus is transmitted to the sight mark imaging module for clear imaging; The signal light source module and the scale light source module are both connected to the data acquisition card, the data acquisition card is connected to the data processing unit, and the data processing unit is connected to the optical delay line.

2. The all-in-one eyeball comprehensive parameter measuring instrument according to claim 1, characterized in that: The signal light source module includes a signal light source, an optical fiber circulator, a photoelectric balanced detector, a first optical fiber coupler, a signal light source sample arm and a signal light source reference arm; The signal light source emits light that passes through the fiber optic circulator and enters the first fiber optic coupler from the fiber optic circulator. The first fiber optic coupler divides the light into two beams that enter the signal light source sample arm and the signal light source reference arm respectively. The light from the signal light source sample arm is deflected in the optical path by a dichroic mirror and then transmitted to the measurement eyeball reflection, and the returned light re-enters the third port of the first fiber optic coupler. The signal light source reference arm is connected to a wavelength division multiplexer and an optical delay line. The light from the signal light source reference arm is reflected by the optical delay line and the returned light re-enters the fourth port of the first fiber optic coupler. The two return lights that enter the first fiber optic coupler interfere and are respectively input into the fiber optic circulator and the photoelectric balanced detector from the first port and the second port of the first fiber optic coupler. The fiber optic circulator is connected to the photoelectric balanced detector, and the photoelectric balanced detector amplifies the two differentials, converts them into electrical signals, and transmits them to the data acquisition card.

3. The all-in-one eyeball comprehensive parameter measuring instrument according to claim 2, characterized in that: The signal light source sample arm comprises a first optical fiber collimator, a first beam splitter, a signal light source test arm, a signal light source zero point arm and a first polarization controller; the signal light source reference arm is provided with a second polarization controller; The light from the signal light source sample arm passes through the first optical fiber collimator and enters the first beam splitter, and is divided into two beams of light that respectively enter the signal light source test arm and the signal light source zero point arm. The signal light source test arm and the signal light source zero point arm can reflect the light, and the returned photosynthetic beam re-enters the third port of the first optical fiber coupler; The first polarization controller is used to control the polarization state of the light returned from the sample arm of the signal light source, and the second polarization controller is used to control the polarization state of the light returned from the reference arm of the signal light source.

4. The all-in-one eyeball comprehensive parameter measuring instrument according to claim 1, characterized in that: The scale light source module includes a scale light source, a photoelectric unit detector, a second optical fiber coupler, a scale light source sample arm, a scale light source reference arm and an optical fiber reflector; The light emitted by the scale light source is divided into two beams by the second optical fiber coupler, and enters the scale light source sample arm and the scale light source reference arm respectively. The scale light source sample arm is connected to the optical fiber reflector. After the light is reflected by the optical fiber reflector, the returned light enters the third port of the second optical fiber coupler. The light of the scale light source reference arm is transmitted from the wavelength division multiplexer to the optical delay line. After the light is reflected by the optical delay line, the returned light enters the fourth port of the second optical fiber coupler. The two return lights entering the second optical fiber coupler interfere with each other and come out from the first port and the second port of the second optical fiber coupler respectively, and then are respectively input into the scale light source and the photoelectric unit detector. The photoelectric unit detector converts the optical signal into an electrical signal, and then transmits it to the data acquisition card.

5. The all-in-one eyeball comprehensive parameter measuring instrument according to claim 1, characterized in that: The optical delay line comprises a second optical fiber collimator, a voice coil motor, a right-angle prism, a hollow roof prism, a fifth plane reflector, a sixth plane reflector and a cemented lens. The hollow roof prism is installed in front of the voice coil motor, the right-angle prism is fixedly installed in front of the hollow roof surface of the hollow roof prism, the fifth plane reflector and the sixth plane reflector are installed on the left and right sides of the right-angle prism, and the sixth plane reflector is installed in front of the cemented lens. After the light is collimated by the second optical fiber collimator, it is transmitted to the fifth reflector, and after the light path is deflected, it is transmitted back and forth between the right-angle prism and the hollow roof prism, and then it is converged by the cemented lens and focused and reflected at the sixth reflector. After the light path is transmitted along the original path, it is re-coupled into the second optical fiber collimator.

6. The all-in-one eyeball comprehensive parameter measuring instrument according to claim 1, characterized in that: The lighting imaging module includes a telecentric lens and a first camera; The light emitted by the annular light source is reflected by the cornea, and the reflected light is imaged by the first camera after passing through the dichroic mirror, the second beam splitter and the telecentric lens.

7. The all-in-one eyeball comprehensive parameter measuring instrument according to claim 1, characterized in that: The sight mark lighting module includes a sight mark light source, a sight mark, a first lens, a reflector and a second lens; The sight mark light source illuminates the sight mark, and the illumination light is focused by the first lens, then deflected by the reflector, and then focused into parallel light by the second lens; then, after being transmitted by the third beam splitter and reflected by the second beam splitter, it is transmitted by the dichroic mirror and finally imaged on the retina.

8. The all-in-one eyeball comprehensive parameter measuring instrument according to claim 1, characterized in that: The sight mark imaging module includes a zoom lens group and a second camera; The sight mark image returns along the original path after being reflected, is transmitted through the dichroic mirror, enters the zoom lens group after being reflected by the second beam splitter and the third beam splitter, and is finally imaged by the second camera.

9. The all-in-one eyeball comprehensive parameter measuring instrument according to claim 8, characterized in that: The zoom lens group is provided with a movable lens, through which the focal length of the system is changed so that the second camera can form a clear image. The refractive power of the eyeball can be measured by the position of the movable lens on the zoom lens group.

10. A measurement method using the all-in-one eyeball comprehensive parameter measuring instrument as claimed in claim 1, the method comprising the following steps: Step S1: adjusting the distance between the annular light source and the model cornea to make the image on the illumination imaging module clear, and calculating the center of mass and the inner and outer ring diameters to obtain the corneal curvature; Step S2: adjusting the sight mark imaging module so that the image on it is clear, thereby obtaining the eyeball diopter; Step S3: dynamically adjust the distance between the annular light source and the cornea so that the illumination imaging module forms a clear image, adjust the detection light to be incident on the eyeball, and also adjust the optical path from the signal light source module to the cornea. The data acquisition card dynamically acquires the interference signal measurement data of the signal light source module. Step S4: performing mean subtraction, bandpass, and smoothing filtering on the interference signal measurement data, and then calculating the cross-correlation to obtain a signal waveform with a prominent peak signal; Step S5: Use the processed signal waveform to search for peak values, find the signal peak value and obtain position information; Step S6: synchronously acquiring the interference peak of the scale light source module closest to the position information obtained in step S5 by using the scale light source module and the signal light source module to share the same optical delay line; Step S7: using the interference peak of the ruler light source module as an endogenous position ruler, using the number of interference waveforms of the ruler light source module to calculate the corresponding peak position information interval distance obtained in step S6, and calculating the data of each tissue structure of the human eye.

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