A fully automatic multi-focus ophthalmic biometric measurement system and measurement method

Abstract

A fully automatic multi-focus ophthalmic biometric measurement system and measurement method, relating to ophthalmic biometric measurement technology, comprising: an optical fiber assembly, which includes a measurement optical path and a scale optical path that are independently arranged; a measurement assembly, which includes a collimator, a multi-focus lens, a dichroic mirror, and an illumination target ring connected to a first coupler, and an eye imaging module is provided on the reflection path of the dichroic mirror, and the multi-focus lens focuses the incident measurement light on different surfaces of each tissue structure of the eye; a delay line assembly for changing the optical path and / or measuring the change amount of the optical path; a control assembly respectively connected to the optical fiber assembly, the measurement assembly, and the delay line assembly; a computer connected to the control assembly, and obtaining ophthalmic biometric parameters according to the interference peaks and eye images of different reflection surfaces of the eye. By using a multi-focus lens, the intensity of the detection signals on the crystal surface and the retina surface is improved, and it is easy to detect the signals of each tissue interface of the patient's eye. It has the characteristics of simple structure, low human eye optical power, convenient installation and adjustment, compact system, and high precision.

Description

Technical Field

[0001] The present invention relates to an ophthalmic biological parameter measurement technology, and particularly to a full-automatic multi-focus ophthalmic biological parameter measurement system and a measurement method. Background Art

[0002] Ophthalmic biological parameters include axial length of the eye, corneal thickness, anterior chamber depth, lens thickness, vitreous thickness, corneal curvature, pupil size, etc. Among them, the axial length of the eye refers to the distance from the anterior surface of the cornea to the retinal pigment epithelium layer. These parameters can provide a scientific basis for the judgment of various eye diseases such as refractive error, glaucoma, cataract, strabismus, amblyopia, and macular edema. Compared with normal eyes, in angle-closure glaucoma, the anterior chamber is thin, the lens is thick, the vitreous is thin, and the axial length of the eye is shorter. Therefore, the accurate measurement of ophthalmic biological parameters is particularly important, and its industrialization prospect is very huge.

[0003] Currently, the methods for measuring the axial length of the eye mainly include ultrasonic measurement and optical measurement. The traditional method for measuring the axial length of the eye mainly uses ultrasonic measurement. By receiving the ultrasonic echo signals of different layers of the eyeball, the depth information of the eyeball can be obtained. The measurement accuracy is only 100μm to 200μm. It is necessary to contact the cornea and anesthetize the corneal surface, and it is easy to damage and infect the cornea. Optical axial length measurement uses optical coherence technology to measure the axial length of the eye, which has the advantages of non-contact, high precision, and simple operation. However, this measurement method usually uses an ordinary single-focus lens to converge the light entering the human eye at the cornea. By reflecting through the interfaces of various tissues in the eye and detecting its low-coherence signal, at this time, the light spot energy at the cornea is relatively concentrated, and the energy becomes more divergent towards the back. For example, the light spots at the lens and retina are relatively large, which will cause the signal intensities detected by the reflections on the lens surface and the retina surface to be relatively weak.

[0004] In order to improve the signal intensities detected on the lens surface and the retina surface, the existing methods mainly include:

[0005] 1) Increasing the optical power entering the human eye, but it is easy to increase the risk of the safe power of the human eye;

[0006] 2) The dual optical path channel method is adopted. For example, Chinese Patent CN118370512A discloses an ophthalmic biological parameter measurement system and method, and US Patent US6806963B1 discloses a device and method for measuring the optical properties of at least two regions located at a distance from one another in a transparent and / or diffuse object (Method and device for measuring the optical properties of at least two regions located at a distance from one another in a transparent and / or diffuse object). In both cases, light is split into two beams by a beam splitter and converged onto the anterior segment and posterior segment of the eye respectively. However, this increases the complexity of the system structure and also requires ensuring equal optical paths or compensation.

[0007] 3) The dual-focus combined lens method is adopted. For example, Chinese Patent CN104013383A discloses a dual-focus anterior and posterior segment synchronous imaging system and imaging method, in which two types of lenses are nested and combined mechanically. Since the light spot entering the human eye is small, with a diameter of 1 - 4 mm, the light spot needs to be expanded and then contracted, which increases the complexity of the system structure and the difficulty of system alignment and adjustment, and is not conducive to the compactness of the system.

[0008] 4) The time-division single-channel method is adopted. For example, US Patent US8049899B2 discloses a device and method for measuring the geometric dimensions of an object (Method and Apparatus for Determination of Geometric Values on an Object). By alternately changing the components in the optical path, it focuses on the anterior segment and posterior segment of the eye alternately at different time periods. However, its signal acquisition is not synchronous, and eye tremors or slight head movements will cause large errors, affecting the measurement accuracy.

[0009] 5) The continuous zoom method is adopted. For example, US Patent US7695137B2 discloses a short-coherence interferometric measurement device for axial length measurement on the eye (Short-Coherence Interferometeric Measurement of Length on the Eye). The zoom module is driven by a motor to move, changing the focusing position in the eyeball, and its system structure is complex.

[0010] These methods have the characteristics of high light power entering the human eye, complex system structure, complex alignment and adjustment, non-compact system, and low accuracy.

[0011] In view of the above problems, it is necessary to provide a new type of fully automatic multi-focus ophthalmic biometric measurement system to solve the above problems, improve the intensity of detection signals on the crystal surface and the retina surface, facilitate the detection of signals at the interfaces of various tissues of the patient's eyeball, meet the needs of medical staff for examining various patients, and have the characteristics of simple structure, low human eye optical power, convenient installation and adjustment, compact system, and high precision. Summary of the Invention

[0012] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a fully automatic multi-focus ophthalmic biometric measurement system and a measurement method.

[0013] To achieve the above purpose, the present invention provides the following technical solutions:

[0014] A fully automatic multi-focus ophthalmic biometric measurement system, which includes:

[0015] An optical fiber assembly, which includes a measurement optical path and a scale optical path that are independently arranged,

[0016] The measurement optical path includes a measurement light source for providing measurement light, a first coupler for splitting the measurement light into two beams of light, a polarization device for changing the polarization state of the light in the optical fiber, and a first detector for receiving the reflected measurement light. One of the two beams of light enters the measurement assembly as the signal light for detecting the positions of different reflection surfaces of the eyeball, and the other beam of light enters the delay line assembly as the reference light to accurately locate the positions of different reflection surfaces of the eyeball by scanning and form a low-coherence interference peak with the signal light.

[0017] The scale optical path includes a scale light source for providing scale light, a second coupler for splitting the scale light into two beams of light, and a second detector for receiving the reflected scale light. One of the two beams of light enters the optical fiber end face mirror, and the other beam of light is coupled with the reference light of the measurement light source and enters the delay line assembly through a wavelength division multiplexer. The two beams of light form a high-coherence interference peak, and the amount of optical path change is measured by the number of interference peaks of the scale light.

[0018] A measurement assembly, which includes a collimator connected to the first coupler, a multi-focus lens, a dichroic mirror for beam splitting, and an illumination target ring for providing an eyeball illumination light source, which are arranged in sequence along the optical path. An eyeball imaging module is provided on the reflection path of the dichroic mirror, and the multi-focus lens focuses the incident measurement light on different surfaces of various tissue structures of the eyeball.

[0019] A delay line assembly, connected to the optical fiber assembly, for changing the optical path and / or measuring the amount of optical path change;

[0020] A control assembly, respectively connected to the optical fiber assembly, the measurement assembly, and the delay line assembly;

[0021] A computer, connected to the control component, obtains ophthalmic biological parameters based on the interference peaks and eye images of different reflection surfaces of the eyeball.

[0022] The multi-focal lens is a compound curved lens, which is divided into an inner ring lens of the spot illumination part and an outer ring lens of the non-spot illumination part from the inside to the outside. The inner ring lens of the spot illumination part is composed of a plurality of sub-lenses with different focal lengths spliced together.

[0023] The inner ring lens of the spot illumination part is divided into several regions, and each region corresponds to an inner sub-lens.

[0024] The light passing area of each inner sub-lens is 0.5 to 1.5 times the average light passing area of all inner sub-lenses.

[0025] The focal points of the inner sub-lenses are respectively located at different surfaces of the cornea, lens and retina, and the spot energy distributed on the retina or lens is greater than the focal energy distributed on the cornea.

[0026] The sub-lens is any one of a spherical lens, an aspherical lens, a microlens array sub-lens and a plano-convex lens.

[0027] The focal length of each sub-lens satisfies:

[0028]

[0029] where is the focal length of the sub-lens focused on the k th surface of the eyeball, and the k th surfaces = 1 to 5 are the anterior surface of the cornea, the posterior surface of the cornea, the anterior surface of the lens, the posterior surface of the lens and the retina respectively; is the object distance of the i th surface, ; is the radius of curvature of the i th surface of the eyeball; and are respectively the distance and refractive index between the i th surface and the i +1th surface of the eyeball, .

[0030] The deviation amount between the center thickness of each sub-lens and the outer ring lens is compensated according to , where is the refractive index of the sub-lens, is the center thickness deviation amount of the sub-lens.

[0031] The compound surface lens is formed by direct integral machining, by direct molding with a mold, or by combining different curvature surface type thin sheets pasted on a single focus lens.

[0032] A measurement method based on the full-automatic multi-focus ophthalmic biometric measurement system described above, which includes the following steps:

[0033] 1. The operator inputs the eye information of the person to be photographed. According to the left or right eye, the pupil automatic positioning component is driven, and the host moves left and right to achieve rough left and right positioning of the pupil.

[0034] 2. Rough up and down positioning of the pupil: The person to be photographed leans their head on the jaw rest. The eye imaging module records the pupil image at this time. The computer analyzes the pupil offset amount and transmits the obtained pupil offset amount to the control component. The control component drives the jaw rest movement component to move up and down, thereby achieving rough up and down positioning of the pupil.

[0035] 3. Three-dimensional fine positioning of the pupil: First, according to the signal light spot position calibrated in the software in the eye imaging camera, the pupil image center point is analyzed in real time by the software; then, the offset amount between the pupil center point and the signal light spot center point is analyzed by the software, so that the offset amount can be calculated; finally, according to the offset amount, the host three-dimensional motion mechanism is driven to move, and the pupil is adjusted to the correct position, thereby achieving real-time precise positioning of the pupil.

[0036] 4. Data acquisition and analysis: By collecting the interference peaks of different reflection surfaces of the eye, axial parameters of the eye are obtained, including axial length, corneal thickness, anterior chamber depth, lens thickness. The near-infrared light source and the visible light source are respectively controlled by the illumination light source control module to be turned on and off in sequence, and the corneal radius of curvature, axis angle, pupil size, and white-to-white parameter are obtained.

[0037] The beneficial effects of the present invention: The design is ingenious and unique. A new type of multi-focus lens is adopted, which improves the intensity of the detection signals on the crystal surface and the retina surface, is easy to detect the signals of each tissue interface of the patient's eye, and has the characteristics of simple structure, low human eye power, convenient installation and adjustment, compact system, and high precision. Description of the Drawings

[0038] Figure 1 is a schematic structural diagram of the full-automatic multi-focus ophthalmic biometric measurement system of the present invention.

[0039] Figure 2 is a schematic structural diagram of the multi-focus lens of the present invention.

[0040] Figure 3 is a schematic structural diagram of a single sub-lens of the present invention.

[0041] Figure 4It is a schematic structural diagram of the third specific embodiment of the four different division methods of the multi-focus lens of the present invention.

[0042] Figure 5 It is a schematic structural diagram of a specific embodiment of the ray tracing of the multi-focus lens of the system of the present invention.

[0043] Figure 6 It is a schematic structural diagram of a specific embodiment of the six-focus lens of the system of the present invention.

[0044] Figure 7 It is a schematic structural diagram of a specific embodiment of the five-focus lens of the system of the present invention.

[0045] Figure 8 It is a schematic structural diagram of a specific embodiment of the four-focus lens of the system of the present invention.

[0046] Figure 9 It is a schematic structural diagram of a specific embodiment of the three-focus lens of the system of the present invention.

[0047] Figure 10 It is a block diagram composed of the control component and related important components of the system of the present invention.

[0048] In the figure, 1 is an optical fiber component, 11 is a measurement light source, 12 is a detector, 13 is a coupler, 14 is a polarization device, 15 is a scale light source, 16 is a detector, 17 is a coupler, 18 is a wavelength division multiplexer, 19 is an optical fiber end face mirror; 2 is a measurement component, 21 is a collimator, 22 is a multi-focus lens, 23 is a dichroic mirror, 24 is an illumination target ring, 25 is an eye imaging module; 3 is a delay line component; 4 is a control component; 5 is a computer, 41 is an image processing module, 42 is a detector control module, 43 is an illumination light source control module, 44 is a jaw support movement control module, 45 is a pupil automatic positioning control module, 6 is a jaw support movement component, 7 is a pupil automatic positioning component, 223 is a sub-lens, 221 is an inner ring lens of the spot illumination part, 222 is an outer ring lens of the non-spot illumination part, 2213 is an inner sub-lens, 2223 is an outer sub-lens. Specific Embodiments

[0049] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0050] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture (as shown in the accompanying drawings). If this specific posture changes, the directional indications will also change accordingly.

[0051] As Figure 1 shown, the present invention provides a fully automatic multi - focus ophthalmic biometric measurement system, which includes an optical fiber assembly 1, a measurement assembly 2, a delay line assembly 3, a control assembly 4, and a computer 5.

[0052] The optical fiber assembly 1 includes a measurement optical path and a scale optical path that are independently arranged.

[0053] The measurement optical path includes a measurement light source 11 for providing measurement light, a first coupler 13 for splitting the measurement light into two beams of light, a polarization device 14 for changing the polarization state of the light in the optical fiber, and a first detector 12 for receiving the reflected measurement light. One of the two beams of light enters the measurement assembly as a signal light for detecting the positions of different reflection surfaces of the eyeball, and the other beam of light enters the delay line assembly 3 as a reference light to accurately locate the positions of different reflection surfaces of the eyeball by scanning and form a low - coherence interference peak with the signal light.

[0054] The scale optical path includes a scale light source 15 for providing scale light, a second coupler 17 for splitting the scale light into two beams of light, and a second detector 16 for receiving the reflected scale light. One of the two beams of light enters the optical fiber end - face mirror 19, and the other beam of light is coupled with the reference light of the measurement light source and enters the delay line assembly 3 via a wavelength - division multiplexer 18. The two beams of light form a high - coherence interference peak, and the amount of optical path change is measured by the number of interference peaks of the scale light.

[0055] The optical fiber assembly 1 is connected to the measurement assembly 2 and the delay line assembly 3 respectively through the first coupler 13.

[0056] The optical fiber end - face mirror 19 refers to a plane mirror with a certain reflectivity fixed at the end face of the optical fiber. The scale light source 15 splits the scale light into two beams of light through the second coupler 17. One beam enters the optical fiber end - face mirror 19, and the other beam is coupled with the reference light of the measurement light source 11 and enters the delay line assembly 3. The two beams of light form a high - coherence interference peak, and the amount of optical path change is measured by the number of interference peaks of the scale light, with higher accuracy.

[0057] The measurement light source 11 preferably can adopt a near - infrared super - luminescent light - emitting diode light source, and its central wavelength can be 760 - 900 nm. The scale light source 15 preferably can adopt a near - infrared highly coherent laser light source.

[0058] A measurement component 2, which includes a collimator 21 connected to a first coupler, a multi-focus lens, a dichroic mirror for beam splitting, and an illumination target ring for providing an eye illumination light source, arranged in sequence along an optical path. An eye imaging module is provided on the reflection path of the dichroic mirror, and the multi-focus lens focuses the incident measurement light on different surfaces of various tissue structures of the eye.

[0059] The collimator 21 is connected to one end of the first coupler 13. The illumination target ring 24 is an eye illumination light source, and the eye illumination light source includes a near-infrared light source and a visible light source. The near-infrared light source is used for pupil illumination, and the visible light source is used for iris illumination. Preferably, the near-infrared light source can adopt a 900 - 1000nm LED, and the visible light can adopt white light or green light. The eye illumination light and the signal light are split by the dichroic mirror 23. The dichroic mirror 23 transmits the signal light and reflects the eye illumination light respectively, and its signal light transmittance and illumination light reflectance are both greater than 0.95. The eye imaging module 25 includes a camera, an imaging objective lens, and a protective glass, and the imaging objective lens can adopt a doublet lens or a double telecentric lens.

[0060] A delay line component 3, connected to the optical fiber component, for changing the optical path and / or measuring the change amount of the optical path; the delay line component 3 can adopt any suitable structure, and can include a motor, a linear guide rail or a turntable, and a mirror. The mirror is located on the linear guide rail or the turntable and moves along with the guide rail or the turntable to change the optical path of the reference light returning, and at the same time, the change amount of the optical path can also be measured by the rotation amount of the motor.

[0061] A control component 4, connected to the optical fiber component, the measurement component, and the delay line component respectively;

[0062] A computer 5, connected to the control component 4, obtains ophthalmic biological parameters based on the interference peaks and eye images of different reflection surfaces of the eye. Among them, the axial parameters of the eye, including the axial length of the eye, corneal thickness, anterior chamber depth, and lens thickness, can be obtained by using the interference peaks of different reflection surfaces of the eye, and the corneal curvature radius, axis angle, pupil size, and white-to-white parameter can be obtained by using the eye image.

[0063] As Figure 2 shown, the multi-focus lens 22 is a compound curved surface lens, and the compound curved surface lens 22 is spliced by sub-lenses 223 with different focal lengths having a certain central thickness and a certain shape. The central thickness refers to the central thickness of the complete lens where the sub-lenses 223 are located. As Figure 3As shown, it is divided from the inside to the outside into an inner ring lens 221 of the light spot irradiation part and an outer ring lens 222 of the non-light spot irradiation part. The inner ring lens 221 of the light spot irradiation part is composed of a plurality of sub-lenses 223 with different focal lengths spliced together.

[0064] The inner ring lens 221 of the light spot irradiation part is divided into several regions, and each region corresponds to an inner sub-lens 2213.

[0065] The inner ring lens 221 of the light spot irradiation part is divided into multiple regions according to a certain division method. The division method can be divided according to a certain area and a certain shape; in a specific embodiment of the four-region division method of the present invention, as Figure 4 shown, the shape can be one or more of a circle, a square, a triangle or an irregular shape, etc.

[0066] There are 2 to 5 regions in the region, preferably 3 regions can be adopted, and each region corresponds to an inner sub-lens 2213. The light passing area of each inner sub-lens 2213 is 0.5 to 1.5 times the average light passing area of the inner sub-lens.

[0067] Preferably, the focal points of the inner sub-lenses 2213 are respectively located on different surfaces of various tissue structures of the eye such as the cornea, the lens and the retina, so that the signal light is respectively focused on different surfaces of various tissue structures of the eye. The light spot energy distributed on the retina or the lens is preferably greater than the focal point energy distributed on the cornea. The outer ring lens 222 of the non-light spot irradiation part is an outer sub-lens 2223 with a focal point located at any position in the eye, and preferably an outer sub-lens 2223 with a focal point located at the cornea can be adopted. The sub-lens 223 can be a spherical lens or an aspherical lens, or a microlens array sub-lens, and preferably a plano-convex lens can be adopted.

[0068] See Figure 5 , the focal length of each sub-lens 223 satisfies:

[0069]

[0070] where is the focal length of the sub-lens focused on the k th surface of the eye, and the k = 1 to 5 surfaces are respectively the anterior surface of the cornea, the posterior surface of the cornea, the anterior surface of the lens, the posterior surface of the lens and the retina; is the object distance of the i th surface, ; is the radius of curvature of the i th surface of the eye; and are respectively the iThe distance and refractive index between the surface and the i +1 surface, .

[0071] The deviation amount between the central thickness of each sub-lens 223 and the central thickness of the outer-ring sub-lens 2223 is compensated according to , where is the refractive index of the sub-lens 223, is the deviation amount of the central thickness of the sub-lens 223. Preferably, the central thickness of each sub-lens 223 is equal.

[0072] The compound aspherical lens 22 can be formed by direct integral machining, can be formed by direct molding with a mold, and can also be formed by combining different curvature surface type thin sheets on a single-focus lens. In a preferred solution, the rear surface of each sub-lens 223 is of the same surface type, and the front surface of each sub-lens 223 is of different surface types. Then, the rear surface of the compound aspherical lens 22 is a common aspherical surface, such as a spherical surface or a plane surface, and the front surface of the compound aspherical lens 22 is a compound aspherical surface composed of a combination of multiple aspherical surfaces.

[0073] Example 1, please refer to Figure 6 As shown, the division method can be a concentric circle division method, which are circular sub-lenses, annular sub-lenses, etc. from the inside to the outside; the sub-lenses can be plano-convex lenses; the compound aspherical lens can be a six-focus lens, that is, composed of six sub-lenses 223; the foci of each sub-lens 223 from the inside to the outside are located on the anterior surface of the cornea, the posterior surface of the cornea, the anterior surface of the lens, the posterior surface of the lens, the retina, and the anterior surface of the cornea (outer-ring sub-lens 2223) respectively. The outer diameters of the light-transmitting apertures of the six sub-lenses 223 are 0.07 D ~0.3 D , 0.27 D ~0.5 D , 0.47 D ~0.7 D , 0.67 D ~0.9 D , 1.0 D and >1.0 D ( D is the spot diameter).

[0074] Example 2, please refer to Figure 7As shown, the division method can be a concentric circle division method, from the inside to the outside, there are circular sub-lenses, annular sub-lenses, etc.; the sub-lenses can be plano-convex lenses; the focal length of the outermost inner circle lens 2213 can be the same as that of the outer circle lens 2223, and can be combined into one sub-lens, and the composite curved lens can be a five-focus lens; the focal points of each sub-lens 223 from the inside to the outside are respectively located on the retina, the anterior surface of the lens, the posterior surface of the lens, the anterior surface of the cornea and the posterior surface of the cornea, and the outer diameters of the light-clearance apertures of the sub-lenses 223 are 0.07 D ~0.3 D , 0.27 D ~0.5 D , 0.47 D ~0.7 D , 0.67 D ~0.9 D and ≥1.0 D ( D is the spot diameter).

[0075] Example 3, see Figure 8 As shown, the division method can be a concentric circle division method, from the inside to the outside, there are circular sub-lenses, annular sub-lenses, etc.; the sub-lenses can be plano-convex lenses; the compound curved lens can be a four-focus lens; each sub-lens 223 has focal points located on the front surface of the cornea, the front surface of the lens, the retina and the front surface of the cornea from the inside to the outside (outer circle lens 2223), and the outer diameter of the light aperture of the sub-lens 223 is 0.17 D ~0.5 D , 0.3 D ~0.77 D , 1.0 D and>1.0 D ( D is the spot diameter).

[0076] The best solution is Figure 9 The division method can be a concentric circle division method, from the inside to the outside, there are circular sub-lenses, annular sub-lenses, etc.; the sub-lenses can be plano-convex lenses; the focal length of the outermost inner circle lens 2213 can be the same as that of the outer circle lens 2223, and can be combined into one sub-lens, and the composite curved lens can be a trifocal lens; the focal points of each sub-lens 223 from the inside to the outside are respectively located on the retina, the front surface of the lens and the front surface of the cornea, and the outer diameters of the light-clearance apertures of the sub-lenses 223 are 0.17 D ~0.5 D , 0.3 D ~0.77 D and ≥1.0 D ( D(where the spot diameter is).

[0077] The described fully automatic multi - focus ophthalmic biometric measurement system further includes a jaw support movement component 6 and a pupil automatic positioning component 7. The jaw support movement component 6 includes a one - dimensional movement mechanism and a jaw support. The one - dimensional movement mechanism can adopt a combination structure of a stepping motor, a slider, and a guide rail that moves up and down. The jaw support is located on the up - and - down movement mechanism, and the jaw support can freely move up and down through the one - dimensional movement mechanism to achieve preliminary vertical positioning of the pupil. The pupil automatic positioning component 7 is a three - dimensional movement mechanism of the host. The three - dimensional movement mechanism of the host can adopt a combination structure of stepping motors, sliders, and guide rails that move left - right, front - back, and up - down. By moving the host left - right, front - back, and up - down, automatic pupil positioning is achieved.

[0078] The described control component 4 includes an image processing module 41, a detector control module 42, an illumination light source control module 43, a jaw support movement control module 44, and a pupil automatic positioning control module 45. The control component 4 is connected to the computer 5.

[0079] Among them, the image processing module 41 is used for eye image processing, the detector control module 42 is used for signal processing received by the detector, the illumination light source control module 43 is used to control the turning on and off of the illumination light source, the jaw support movement control module 44 is used for movement control of the jaw support, and the pupil automatic positioning control module 45 is used for movement control of the pupil automatic positioning component 7.

[0080] The present invention also provides a measurement method based on the described fully automatic multi - focus ophthalmic biometric measurement system, which includes the following steps:

[0081] 1. The operator inputs the eye information of the person to be photographed. According to the left or right eye, the pupil automatic positioning component 7 is driven, and by moving the host left - right, rough left - right positioning of the pupil is achieved;

[0082] 2. Rough vertical positioning of the pupil: The person to be photographed leans their head on the jaw support. The eye imaging module records the pupil image at this time. By analyzing the pupil offset amount through the computer, the obtained pupil offset amount is transmitted to the control component, and the control component drives the jaw support movement component 6 to move up and down, thereby achieving rough vertical positioning of the pupil;

[0083] 3. Three - dimensional fine positioning of the pupil: First, according to the position of the signal light spot in the eye imaging camera calibrated in the software, the center point of the pupil image is analyzed in real - time through the software; then, the offset amount between the pupil center point and the signal light spot center point is analyzed through the software, so that the offset amount can be calculated; finally, according to the offset amount, the three - dimensional movement mechanism of the host is driven to move, and the pupil is adjusted to the correct position, thereby achieving real - time precise positioning of the pupil;

[0084] 4 Data acquisition and analysis: By collecting the interference peaks of different reflection surfaces of the eyeball, axial parameters of the eyeball are obtained, including axial length, corneal thickness, anterior chamber depth, and lens thickness. By controlling the near-infrared light source and visible light source to turn on and off in sequence through the illumination light source control module, the corneal radius of curvature, axis angle, pupil size, and white-to-white parameter are obtained.

[0085] The embodiments should not be regarded as limiting the present invention, but any improvements made based on the spirit of the present invention should be within the protection scope of the present invention.

Claims

1. A fully automatic multifocal ophthalmic biological parameter measurement system, characterized in that: It includes: An optical fiber assembly (1) comprises a measuring optical path and a scale optical path which are independently arranged. The measuring optical path comprises a measuring light source (11) for providing measuring light, a first coupler (13) for dividing the measuring light into two beams of light, a polarizing device (14) for changing the polarization state of light in the optical fiber, and a first detector (12) for receiving the reflected measuring light, wherein one beam of light enters the measuring component as signal light for detecting the positions of different reflection surfaces of the eyeball, and the other beam of light enters the delay line component (3) as reference light for accurately locating the positions of different reflection surfaces of the eyeball through scanning, thereby forming a low-coherence interference peak with the signal light. The scale light path comprises a scale light source (15) for providing scale light, a second coupler (17) for dividing the scale light into two beams of light, and a second detector (16) for receiving the reflected scale light, wherein one beam of light enters the optical fiber end face reflector (19), and the other beam of light is coupled with the reference light of the measurement light source and enters the delay line component (3) via a wavelength division multiplexer (18), the two beams of light form a high coherence interference peak, and the optical path change is measured by the number of the scale light interference peaks; A measuring assembly (2), comprising a collimator (21) connected to a first coupler, a multi-focal lens (22), a dichroic mirror (23) for beam splitting, and an illumination target ring (24) for providing an eyeball illumination light source, which are sequentially arranged along an optical path, and an eyeball imaging module (25) is arranged on a reflection path of the dichroic mirror (23), and the multi-focal lens (22) focuses the measurement light incident therein onto different surfaces of various tissue structures of the eyeball; A delay line component (3), connected to the optical fiber component, used to change the optical path and / or measure the amount of change in the optical path; A control component (4) connected to the optical fiber component, the measuring component and the delay line component respectively; The computer (5) is connected to the control component (4) and acquires ophthalmic biological parameters based on the interference peaks of different reflective surfaces of the eyeball and the eyeball image collected. The multi-focal lens (22) is a composite curved lens, which is divided from the inside to the outside into an inner ring lens (221) of a spot illumination part and an outer ring lens (222) of a non-spot illumination part, wherein the inner ring lens (221) of the spot illumination part is composed of a plurality of sub-lenses (223) with different focal lengths spliced ​​together. The focal length of each sub-lens (223) satisfies: in The sub-lens focuses on the eyeball k The focal length of the surface, k =1~5 surfaces are the anterior surface of the cornea, the posterior surface of the cornea, the anterior surface of the lens, the posterior surface of the lens and the retina; For the i The object distance of the surface, ; For the eye i The radius of curvature of the surface; and Eyeball i Surface and i +1 The distance between the surfaces and the refractive index, .

2. The fully automatic multifocal ophthalmic biological parameter measurement system according to claim 1, characterized in that: The inner circle lens (221) of the light spot irradiation portion is divided into a plurality of regions, and each region corresponds to an inner circle lens (2213).

3. The fully automatic multifocal ophthalmic biological parameter measurement system according to claim 2, characterized in that: The light transmission area of ​​each inner circle lens (2213) is 0.5 to 1.5 times the average light transmission area of ​​all inner circle lenses.

4. The fully automatic multifocal ophthalmic biological parameter measurement system according to claim 2, characterized in that: The focal points of the inner circle lens (2213) are located on different surfaces of the cornea, the lens and the retina, respectively, and the light spot energy distributed on the retina or the lens is greater than the focal point energy distributed on the cornea.

5. The fully automatic multifocal ophthalmic biological parameter measurement system according to claim 2, characterized in that: The sub-lens (223) is any one of a spherical lens, an aspherical lens, a microlens array sub-lens and a plano-convex lens.

6. A fully automatic multifocal ophthalmic biological parameter measurement system according to any one of claims 1 to 5, characterized in that: The deviation between the center thickness of each sub-lens (223) and the outer ring lens (2223) is calculated according to Compensation, including is the refractive index of the sub-lens (223), is the central thickness deviation of the sub-lens (223).

7. A fully automatic multifocal ophthalmic biological parameter measurement system according to any one of claims 1 to 5, characterized in that: The composite curved lens is formed by direct integral processing, direct mold forming, or by combining thin sheets with different curvatures pasted on a single-focus lens.

8. A measurement method based on the fully automatic multifocal ophthalmic biological parameter measurement system according to any one of claims 1 to 7, characterized in that: It includes the following steps: 1) The operator inputs the subject's eye information, and according to the left and right eyes, the pupil automatic positioning component (7) is driven, and the host moves left and right to achieve rough left and right positioning of the pupil; 2) Rough positioning of the pupil: The subject rests his head on the chin rest, and the eye imaging module records the pupil image at this time. The computer analyzes the pupil offset and transmits the obtained pupil offset to the control component. The control component drives the chin rest motion component (6) to move up and down, thereby achieving rough positioning of the pupil; 3) 3D pupil positioning: First, the position of the signal light spot in the eye imaging camera is calibrated in the software, and the center point of the pupil image is analyzed in real time by the software; then, the offset between the center point of the pupil and the center point of the signal light spot is analyzed by the software, so that the offset can be calculated; finally, the host 3D motion mechanism is driven to move according to the offset, and the pupil is adjusted to the correct position, thereby realizing real-time and accurate pupil positioning; 4) Data collection and analysis: By collecting the interference peaks of different reflective surfaces of the eyeball, the axial parameters of the eyeball are obtained, including axial length, corneal thickness, anterior chamber depth, and lens thickness. The near-infrared light source and visible light source are controlled to be turned on and off in sequence through the lighting source control module to obtain the corneal curvature radius, axial angle, pupil size, and white-to-white parameters.

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