Ophthalmology measurement system based on carrier frequency loading device

Abstract

The invention provides an ophthalmology measurement system based on a carrier frequency loading device, which comprises an OCT light source, a reference arm, a sample arm module, an optical fiber coupler and a detector, and is characterized in that the sample arm module is integrated with an optical path switching scanning device and can reflect detection light to a posterior segment or anterior segment optical path. The optical path is dynamically adjusted by introducing a carrier frequency adding device, the A-Scan optical path or phase change is kept constant, Doppler frequency shift is achieved, and the detection depth is enhanced without losing resolution. The system can quickly switch imaging focuses to adapt to eyes with different eyesight, and refraction compensation is carried out to obtain high-resolution OCT (Optical Coherence Tomography) images. In addition, the system can accurately measure key parameters such as corneal curvature, thickness, anterior chamber depth, crystalline lens thickness and the like, and the diagnosis speed is effectively improved. According to the invention, while the imaging quality is ensured, the limitations on detection depth, imaging speed and precision in the prior art are solved.

Description

Technical Field

[0001] The invention relates to ophthalmic optical coherence tomography technology, in particular to an ophthalmic measurement system based on a frequency loading device. Background Art

[0002] Nowadays, more and more elderly people suffer from cataracts, and transplanting artificial lenses is an effective and widely used treatment for cataracts. However, the calculation of artificial lenses requires many parameters, such as the curvature of the anterior and posterior surfaces of the cornea, corneal thickness, anterior chamber depth, lens thickness, the curvature of the anterior and posterior surfaces of the lens, and axial length. There are many parameters to be measured, but it often requires multiple medical devices to detect them before the above complete data can be obtained. Therefore, if a medical device can be implemented that can obtain the above data, it can not only improve the convenience of measurement for patient testing, but also improve the accuracy of measurement.

[0003] With the in-depth research and development of ophthalmology, the medical community has found that the myopia problem of adolescents is closely related to the growth of their axial length. During the growth and development of adolescents, if the axial length grows too fast, it is often accompanied by the rapid deepening of myopia. Therefore, when preventing and controlling myopia in adolescents, studying and tracking the growth changes of the axial length of adolescents is also one of the important indicators of their ophthalmic parameters.

[0004] Optical coherence tomography (OCT) is an emerging optical imaging technology. Compared with traditional clinical imaging methods, it has the advantages of high resolution, fast imaging speed, no radiation damage, moderate price, and compact structure. It is an important potential tool for basic medical research and clinical diagnosis applications. Currently, among the various ophthalmic devices using optical instruments, OCT devices used for ophthalmic examination and treatment have become an indispensable ophthalmic device for the diagnosis of ophthalmic diseases.

[0005] 1) The existing technology for measuring shaft length often uses time domain tomography technology, which is slow and has low measurement accuracy.

[0006] Patent document 200710020707.9 discloses a method for measuring the axial length of the eye using OCT. Although this method can measure the axial length of the human eye and various living animals, it has the following two disadvantages: 1. The moving probe of the stepping motor is used to adjust the optical path, thereby realizing the imaging of the cornea and the fundus. However, it takes a certain amount of time for the motor to move back and forth, and it is impossible to achieve rapid switching between the front and back segments and real-time imaging. In addition, the eyes of the measured object will shake, making the measurement of the axial length inaccurate and the error large; 2. Due to the different structures of the cornea and the fundus, the same probe cannot be focused at both positions, resulting in poor imaging quality, which is an unavoidable defect of this method.

[0007] 2) The existing patent "An OCT system and method for measuring the optical path value of the eye axis, application number 201410214827.2" introduces corneal position alignment technology, which does not require switching between the anterior and posterior segments, but does not have the anterior segment measurement function and the corneal curvature measurement function (or does not mention it). Measuring the cornea requires an additional operation. It is impossible to achieve rapid diagnosis of patients.

[0008] 3) With the existing patents “Ophthalmic Measurement System and Method, Application No. 201810130278.9” and “Ophthalmic Measurement System, Application No. 201910116857.2”, it is difficult to deepen the detection depth of the OCT system.

[0009] 4) The existing patent "Ophthalmic measurement system based on shutter switching, application number 202020735955.2" measures the anterior chamber depth and lens thickness, and also uses OCT data after the optical path is switched twice to calculate the axial length. This switching speed will affect the measurement accuracy of the anterior chamber depth and lens thickness.

[0010] It uses frequency-domain optical coherence tomography technology, which has faster scanning speed and higher imaging resolution than time-domain OCT systems, but a shallow detection depth. Compared with scanning frequency-domain optical coherence tomography technology, it has comparable scanning speed and resolution, and is much less expensive, but a shallow detection depth.

[0011] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0012] The main purpose of the present invention is to overcome the defects existing in the above-mentioned background technology and provide an ophthalmic measurement system based on a frequency loading device.

[0013] To achieve the above object, the present invention adopts the following technical solutions:

[0014] An ophthalmic measurement system based on a frequency-adding device comprises an OCT imaging module, wherein the OCT imaging module comprises an OCT light source, a reference arm module, an OCT sample arm module, an optical fiber coupler and a detector, wherein the OCT sample arm module comprises an optical path switching scanning device, a posterior segment OCT sample arm optical path and an anterior segment OCT sample arm optical path, wherein the detection light output by the optical fiber coupler is reflected at different angles by the optical path switching scanning device and then enters the posterior segment OCT sample arm optical path or the anterior segment OCT sample arm optical path respectively; and further comprises a frequency-adding device, which is used to change the optical path during the OCT scanning process and keep the optical path or phase change between adjacent OCT scans A-Scans constant, thereby introducing a Doppler frequency shift into the detection light.

[0015] Furthermore, the frequency loading device includes a motor and a flat glass, and the motor drives the flat glass to deflect or rotate to dynamically adjust the optical path; the optical path switching scanning device adjusts its scanning angle during the scanning process to cooperate with the deflection or rotation of the flat glass, and jointly acts on the detection light to keep the optical path or phase change between adjacent OCT scans A-Scan constant.

[0016] Furthermore, the motor drives the flat glass to deflect to a set angle, so that after the detection light is deflected by the flat glass, it will not hit the rotation center of the rotating reflective mirror of the optical path switching scanning device. The scanning angle change of the optical path switching scanning device during the scanning process is utilized to keep the optical path or phase change between adjacent OCT scans A-Scan constant.

[0017] Furthermore, the motor drives the flat glass to rotate, and scans synchronously with the optical path switching scanning device to generate a changed optical path, and keep the optical path or phase change between adjacent OCT scans A-Scan constant.

[0018] Furthermore, the frequency loading device includes a servo mechanism, and the OCT sample arm module includes a sample arm optical fiber head and an optical fiber collimator. The detection light enters the optical path switching scanning device from the sample arm optical fiber head through the optical fiber collimator. The optical fiber collimator and the sample arm optical fiber head are driven by the servo mechanism so that the two move together as a whole, changing the optical path length of the sample arm, and cooperating with the optical path switching scanning device to perform scanning, so that the optical path or phase change between adjacent OCT scans A-Scan remains constant.

[0019] Furthermore, the frequency loading device includes a servo mechanism, and the reference arm module includes a reference arm fiber head, a reference arm optical path lens and a reference arm reflector. The reference light is emitted from the reference arm fiber head through the reference arm optical path lens and hits the reference arm reflector, and then is reflected by the reference arm reflector and returns to the fiber coupler. The reference arm optical path lens and the reference arm fiber head are driven by the servo mechanism so that the two move together as a whole, changing the optical path length of the reference arm, and cooperating with the optical path switching scanning device to perform scanning so that the optical path or phase change between adjacent OCT scans A-Scan remains constant.

[0020] Furthermore, the anterior chamber OCT sample arm optical path includes an anterior chamber measuring lens, which is configured to cut into or out of the optical path; the anterior chamber measuring lens is designed to cut into the optical path when performing anterior chamber OCT scanning imaging to guide the detection light beam to focus near the center of the anterior chamber of the eye; when performing panoramic OCT scanning imaging of the entire lens, the anterior chamber measuring lens is in a cut-out state.

[0021] Furthermore, the anterior segment OCT sample arm optical path includes a first reflector, a first lens, a third reflector, a fifth reflector, a third lens, a third beam splitter, a front beam splitter and an eyepiece objective lens. After the light beam is reflected by the optical path switching scanning device, it is successively reflected by the first reflector, transmitted by the first lens, and then reflected by the third reflector and the fifth reflector, and then transmitted by the third lens, transmitted by the third beam splitter, and then reflected by the front beam splitter to the eyepiece objective lens, and finally converged to the anterior segment of the human eye through the human eye; wherein, the anterior segment of the human eye chamber insertion lens can be inserted into the anterior segment OCT sample arm optical path.

[0022] Furthermore, the optical path of the posterior segment OCT sample arm includes a light path adjustment module, a posterior segment and a gaze beam splitter, a refractive adjustment device, a third beam splitter, a front beam splitter and an eyepiece objective lens in sequence. After the light beam is reflected by the optical path switching scanning device, it passes through the light path adjustment module, and then is reflected by the posterior segment and the gaze beam splitter, passes through the refractive adjustment device, is reflected by the third beam splitter, and then is reflected by the front beam splitter to the eyepiece objective lens, and finally passes through the human eye to converge to the fundus of the human eye.

[0023] Furthermore, it also includes a computer connected to the detector, which processes the interference signal introduced with the Doppler frequency shift and uses a de-imaging algorithm to obtain an OCT image using positive and negative frequency image data.

[0024] The present invention has the following beneficial effects:

[0025] The ophthalmic measurement system of the present invention realizes efficient and accurate imaging of different parts of the eye by quickly switching the anterior and posterior segment OCT imaging system and combining the Doppler frequency shift technology. The optical path switching scanning device adopted by the system can reflect the detection light at different angles so that it enters the OCT sample arm optical path of the posterior segment or anterior segment of the eye, and dynamically adjusts the optical path by adding a frequency-adding device to keep the optical path or phase change between adjacent OCT scans A-Scan constant, introduce Doppler frequency shift, thereby increasing the detection depth of the system without reducing the detection resolution. This design not only improves the detection range and stability of the OCT system, but also ensures the accuracy of positioning without affecting the system signal-to-noise ratio. In addition, the system can perform refractive compensation for human eyes with different vision, realize high-quality imaging of different parts, and has high lateral resolution. Through fast and accurate optical path switching, the system can realize fast OCT imaging of different parts of the human eye, and accurately measure key ophthalmic parameters such as corneal curvature, corneal thickness, anterior chamber depth, lens thickness, etc., to meet the needs of clinical diagnosis. The present invention effectively overcomes the problems of limited detection depth, slow imaging speed and low measurement accuracy in the prior art, and provides an ophthalmic measurement system that can quickly and accurately obtain multiple optical parameters of the human eye.

[0026] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is an optical path diagram of the OCT system according to Example 1 of the present invention.

[0028] Figure 2 This is a diagram of the posterior segment OCT imaging system of Example 1 of the present invention.

[0029] Figure 3 This is a diagram of the anterior segment OCT imaging system of Example 1 of the present invention.

[0030] Figure 4 The optical path diagram of the OCT system of Example 2 of the present invention

[0031] Figure 5 This is an optical path diagram of the OCT system according to Example 3 of the present invention.

[0032] Figure 6 This is a diagram of the anterior segment OCT imaging system of Example 3 of the present invention. DETAILED DESCRIPTION

[0033] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing as well as for coupling or communication.

[0035] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] See also Figures 1 to 6 An embodiment of the present invention provides an ophthalmic measurement system based on a frequency-adding device, comprising an OCT imaging module, wherein the OCT imaging module comprises an OCT light source 1101, a reference arm module, an OCT sample arm module, a fiber coupler 1103 and a detector 1141, wherein the OCT sample arm module comprises an optical path switching scanning device 1109, a posterior segment OCT sample arm optical path and an anterior segment OCT sample arm optical path, wherein the detection light output by the fiber coupler 1103 is reflected at different angles by the optical path switching scanning device 1109 and enters the posterior segment OCT sample arm optical path or the anterior segment OCT sample arm optical path respectively; and further comprising a frequency-adding device for changing the optical path during the OCT scanning process and keeping the optical path or phase change between adjacent OCT scans A-Scans constant, thereby introducing a Doppler frequency shift into the detection light.

[0038] See also Figures 1 to 3 , Figure 5 and Figure 6 In some embodiments, the frequency loading device includes a motor 1203 and a flat glass 1201, and the motor 1203 drives the flat glass 1201 to deflect or rotate to dynamically adjust the optical path; the optical path switching scanning device 1109 adjusts its scanning angle during the scanning process to cooperate with the deflection or rotation of the flat glass 1201, and jointly acts on the detection light to keep the optical path or phase change between adjacent OCT scans A-Scan constant. In one embodiment, the motor 1203 drives the flat glass 1201 to deflect to a set angle, so that after the detection light is deflected by the flat glass 1201, it will not hit the rotation center of the rotating reflective mirror of the optical path switching scanning device 1109, and the scanning angle change of the optical path switching scanning device 1109 during the scanning process is used to keep the optical path or phase change between adjacent OCT scans A-Scan constant. In another embodiment, the motor 1203 drives the flat glass 1201 to rotate, and scans synchronously with the optical path switching scanning device 1109 to generate a changed optical path, and keep the optical path or phase change between adjacent OCT scans A-Scan constant. The motor 1203 can be a servo motor 1203 suitable for driving a galvanometer system.

[0039] See also Figure 4In some embodiments, the frequency loading device includes a servo mechanism 2205, and the OCT sample arm module includes a sample arm optical fiber head and an optical fiber collimator 1107. The detection light enters the optical path switching scanning device 1109 from the sample arm optical fiber head through the optical fiber collimator 1107. The optical fiber collimator 1107 and the sample arm optical fiber head are driven by the servo mechanism so that the two move together as a whole, changing the optical path length of the sample arm, and cooperating with the optical path switching scanning device 1109 to perform scanning, so that the optical path or phase change between adjacent OCT scans A-Scan remains constant.

[0040] In some embodiments, the frequency loading device includes a servo mechanism (not shown), and the reference arm module includes a reference arm fiber head, a reference arm optical path lens 1121 and a reference arm reflector 1123. The reference light passes from the reference arm fiber head through the reference arm optical path lens 1121 and hits the reference arm reflector 1123, and then is reflected by the reference arm reflector 1123 and returns to the fiber coupler 1103. The reference arm optical path lens 1121 and the reference arm fiber head are driven by the servo mechanism so that the two move together as a whole, changing the optical path length of the reference arm, and cooperating with the optical path switching scanning device 1109 for scanning, so that the optical path or phase change between adjacent OCT scans A-Scan remains constant.

[0041] The fast switching anterior and posterior segment OCT imaging system designed by the present invention combines a scanning device and Doppler frequency shift technology: on the one hand, it has a fast switching function, which can realize the measurement of different depths of objects, improve the detection range of the OCT system (anterior and posterior segment OCT imaging), the switching system is stable, the positioning is accurate, and the system signal-to-noise ratio is not affected; on the other hand, it can realize the focusing of light beams at different positions, and can realize high-quality OCT imaging of different parts for human eyes with different vision, and has a high lateral resolution. The fast switching anterior and posterior segment imaging OCT system can obtain many parameter data of the human eye, such as corneal curvature, corneal thickness, anterior chamber depth, lens thickness, lens surface curvature, axial length, white to white diameter and pupil diameter. It can focus on tissues at different depths of the human eye: anterior chamber, lens and retina, respectively, so as to improve the signal-to-noise ratio and resolution of OCT detection of different tissues. Combined with Doppler frequency shift technology or frequency loading technology, the system detection depth is deepened, while the detection resolution remains unchanged. The present invention effectively solves the problem that the frequency domain system has a shallow detection depth and cannot measure the anterior chamber depth or lens thickness at one time.

[0042] When the probe optical path of the OCT imaging system of the present invention realizes OCT imaging of different parts of the human eye, the scanning mode and focusing position adopted are different, and the optical paths adopted to measure different parts of the human eye are different. During fundus OCT imaging, the center line of the scanning beam converges on the pupil of the human eye, and the OCT beam at any time must be incident on the human eye in parallel; and during anterior segment imaging, the OCT beam at any time must be focused on tissues at different depths of the anterior segment of the human eye. The embodiment of the present invention can perform refractive compensation for human eyes with different vision to realize imaging of different parts of the human eye. When measuring different parts of the anterior segment, the detection beam can be focused on different parts to improve the imaging resolution and signal-to-noise ratio. Fast OCT imaging of different parts of the human eye can be realized by a fast and accurate optical path switching scanning device. On the basis of OCT imaging of different parts of the human eye, the present invention can realize fast and accurate measurement of axial length, anterior chamber depth, lens thickness, etc.

[0043] The fast switching anterior and posterior segment OCT imaging system designed by the present invention combines a scanning device and Doppler frequency shift technology, and realizes efficient and accurate imaging of different parts of the eye through innovative optical path design and control mechanism. The OCT imaging system of the present invention can not only realize fast switching imaging of different parts of the eye, but also can combine Doppler frequency shift technology to deepen the detection depth of the system while maintaining the detection resolution unchanged, effectively solving the limitations of traditional frequency domain systems in terms of detection depth.

[0044] The specific embodiments of the present invention are further described below.

[0045] Example 1

[0046] The optical path diagram of the OCT system of Example 1 is as follows: Figure 1 shown.

[0047] The ophthalmic measurement system based on a frequency-adding device is a fast-switching anterior and posterior segment OCT imaging system that combines a scanning device and Doppler frequency shift technology, including: an OCT imaging module, a posterior segment OCT sample arm module, anterior segment OCT sample arm module, a fixation optical module (not shown) and anterior segment camera module (not shown), and a frequency-adding device.

[0048] The optical path switching scanning device 1109 and the frequency loading device are controlled by a computer to realize optical path switching, thereby achieving OCT imaging of different depths of the human eye.

[0049] OCT imaging module

[0050] The OCT imaging module includes an OCT light source 1101, a fiber coupler 1103, a reference arm module, a detector 1141, a computer 1143 and a sample arm module.

[0051] The reference arm module includes a reference arm optical path lens 1121 and a reference arm reflector 1123 .

[0052] The sample arm module includes a polarization controller 1105, a fiber optic collimator 1107, an optical path switching scanning device 1109, a posterior segment OCT sample arm module, and an anterior segment OCT sample arm module.

[0053] In this embodiment, the frequency loading device is located between the fiber collimator 1107 and the optical path switching scanning device 1109. The frequency loading device is composed of a flat glass 1201 and a motor 1203. The motor 1203 drives the flat glass 1201 to deflect, so as to achieve the change of the optical path, or the shift of the optical path, so as to achieve the effect of Doppler frequency shift, that is, to achieve frequency loading. In other embodiments, the frequency loading device can also be located in the reference arm module, such as between the reference arm optical path lens 1121 and the reference arm reflector 1123.

[0054] The optical path of the OCT imaging module includes a weak coherent light source 1101, the light output by which is provided to the sample arm module and the reference arm module through the fiber coupler 1103. The reference arm module has a known length and reflects the light back to the fiber coupler 1103 through the reference arm reflector 1123. The sample arm module provides light to the human eye E to be tested, and the light scattered back from the sample passes through the sample arm, the polarization controller 1105 and the light reflected back from the reference arm and interferes in the fiber coupler 1103. The interference light is detected by the detector 1141, and then processed by the computer 1143, and finally the OCT image of the sample to be tested is displayed. The sample is scanned by the optical path switching scanning device 1109 to achieve OCT tomographic imaging.

[0055] The OCT light source 1101 outputs light with a wavelength of near infrared.

[0056] Posterior Segment OCT Sample Arm Module

[0057] The posterior segment OCT imaging system of Example 1 is as follows Figure 2 shown.

[0058] The posterior segment sample arm module 130 includes an optical path switching scanning device 1109, an optical path adjustment module 1301, a posterior segment and gaze beam splitter 1303 (a first beam splitter 1303), a refraction adjustment device 1305, a third beam splitter 1307, a front beam splitter 1309 (a fifth beam splitter 1309), and an eye contact objective lens 1311. In this embodiment, the posterior segment sample arm module 130 also includes a flat glass 1201.

[0059] When performing posterior segment OCT imaging, the light emitted from the fiber collimator 1107 passes through the flat glass 1201 and is reflected by the optical path switching scanning device 1109. At this time, the optical path switching scanning device 1109 is controlled by the computer 1143. After the light beam is reflected by the optical path switching scanning device 1109, it passes through the light path adjustment module 1301, and then reflects by the posterior segment and the gaze beam splitter 1303 (the first beam splitter 1303), passes through the refractive adjustment device 1305, is reflected by the third beam splitter 1307, and then is reflected by the front beam splitter 1309 (the fifth beam splitter 1309) to the eye lens 1311, and finally passes through the human eye E to converge to the human eye fundus Er. The detection light beam of the posterior segment OCT imaging optical path system meets the requirement that the center line of the scanning light beam converges near the pupil of the human eye, and the OCT light beam is focused on the human eye fundus Er at any time.

[0060] The optical path switching scanning device 1109 is controlled by the computer 1143 and is in a position to realize the OCT imaging of the posterior segment of the eye. At this time, the position of the optical path switching scanning device 1109 is just such that the angle between the main optical axis of the incident light from the fiber collimator 1107 and the main optical axis of the reflected light is α. The fundus OCT imaging optical path refractive adjustment device 1305 is adjusted for different human eyes (whose refractive powers are different) so that the OCT light beam can converge on the fundus Er of the human eye. That is, the light beam is focused on the retina, which can effectively improve the signal-to-noise ratio and lateral resolution of the OCT image when measuring the retina.

[0061] The optical path switching scanning device 1109 not only performs the function of scanning, but also performs the function of optical path switching. The present invention adopts a galvanometer or other high-precision positioning mechanism to meet the needs of fast switching and scanning of the system optical path. When measuring the fundus, the optical path switching scanning device 1109 is rotated to allow the main optical axis of the optical path to be reflected from the fiber optic collimator 1107 to the light adjustment module 1301, and the main optical axis of the light beam changes by an angle α (as shown in the figure above); and when measuring the front segment of the eye, the optical path switching scanning device 1109 is rotated to allow the main optical axis of the optical path to be reflected from the fiber optic collimator 1107 to the first reflector 1501, and the main optical axis of the light beam changes by an angle β (as shown in the figure below). The optical path switching scanning device 1109 cooperates with the third beam splitter 1307 to realize the switching of the front and rear optical paths.

[0062] The optical path adjustment module 1301 can be formed by a corner cube prism, a right angle prism, or two total reflection mirrors arranged perpendicular to each other. The optical path is changed by moving up and down as shown in the figure.

[0063] The optical path switching scanning device 1109 can be a one-dimensional optical path switching scanning device, or a two-dimensional or even three-dimensional optical path switching scanning device.

[0064] Anterior Segment OCT Sample Arm Module

[0065] The anterior segment OCT imaging system of Example 1 is as follows Figure 3 shown.

[0066] The anterior segment sample arm module includes an optical path switching scanning device 1109, a first reflector 1501, a first lens 1503, a third reflector 1505, a fifth reflector 1507, a third lens 1509, a third beam splitter 1307, a front beam splitter 1309 (fifth beam splitter 1309) and an eyepiece objective lens 1311. In this embodiment, the anterior segment sample arm module also includes a flat glass 1201.

[0067] When performing anterior segment OCT imaging, the light emitted from the fiber collimator 1107 passes through the flat glass 1201 and is reflected by the optical path switching scanning device 1109. At this time, the optical path switching scanning device 1109 is controlled by the computer 1143. After being reflected by the optical path switching scanning device 1109, the light beam is successively reflected by the first reflector 1501, transmitted by the first lens 1503, and then reflected by the third reflector 1505 and the fifth reflector 1507, and then transmitted by the third lens 1509, the third beam splitter 1307, and then reflected by the pre-beam splitter 1309 (fifth beam splitter 1309) to the eyepiece objective lens 1311, and finally converged to the anterior segment of the human eye through the human eye E. The detection light beam of the anterior segment OCT imaging optical path system satisfies the OCT light beam focusing on the anterior segment of the human eye.

[0068] The optical path switching scanning device 1109 is controlled by the computer 1143 and is in a position to realize anterior segment OCT imaging. At this time, the optical path switching scanning device 1109 is in a position that makes the angle between the main optical axis of the incident light from the fiber collimator 1107 and the main optical axis of the reflected light be β.

[0069] In this embodiment, the detection depth of the OCT system is increased by adding frequency-adding technology, or Doppler frequency shift technology, in conjunction with the scanning of the optical path switching scanning device 1109, so that the optical path or phase change between adjacent OCT scans A-Scan remains constant, thereby achieving the elimination of mirror images, thereby achieving the purpose of deepening the OCT detection depth. The detection depth of the OCT system can achieve a one-time detection imaging from the cornea to the rear surface of the lens (the tissue depth from the cornea to the rear surface of the lens is about 8mm), but it is not enough to achieve a single OCT imaging from the cornea to the retina (Note: the average axial length of the human eye from the cornea to the retina is about 24mm (tissue depth)). If the frequency-adding technology is not used, and the scanning frequency domain OCT or the frequency domain spectrometer technology with a deeper detection depth is adopted, although the purpose of increasing the detection depth of the OCT system can be achieved, the cost of the scanning frequency domain OCT or the frequency domain spectrometer technology with a deeper detection depth is often high. For the frequency domain spectrometer technology with a deeper detection depth, the number of pixels of the spectrometer linear array camera often needs to be doubled, and the increase in its cost is often superimposed more times. The frequency-adding technology in this embodiment achieves the purpose of doubling the detection depth by only increasing limited costs while ensuring the same imaging resolution and image quality.

[0070] There are many implementation schemes for the frequency-adding technology. For example, the motor 1203 drives the flat glass 1201 to deflect to a specific angle, so that after the sample arm detection light emitted by the fiber collimator 1107 is deflected by the flat glass 1201, the light spot does not hit the rotation center of the rotating reflective mirror of the optical path switching scanning device 1109. As the optical path switching scanning device 1109 rotates at a high speed, the sample arm detection light is introduced into the Doppler frequency shift. The computer 1143 processes the interference signal that introduces the Doppler frequency shift, and through the OCT de-mirroring algorithm, it can obtain an OCT image that utilizes positive and negative frequency image data, thereby achieving the purpose of doubling the detection depth. In this scheme, the motor 1203 drives the flat glass 1201 to deflect to a specific angle, which can be simply implemented by an electromagnet or a motor mechanical structure, so the cost is relatively low.

[0071] Another solution is to drive the flat glass 1201 to rotate by the motor 1203, and cooperate with the optical path switching scanning device 1109 to scan synchronously, so that after the sample arm detection light emitted by the fiber collimator 1107 passes through the flat glass 1201, the optical path or phase change between adjacent OCT scans A-Scan remains constant. The OCT signal obtained by this method is equivalent to introducing a Doppler frequency shift. The computer 1143 processes the OCT signal obtained by the scanning method, and through the de-mirroring algorithm, it can obtain an OCT image using positive and negative frequency image data, thereby achieving the purpose of doubling the detection depth. In this solution, the motor 1203 drives the flat glass 1201 to rotate, and needs to cooperate with the optical path switching scanning device 1109 to scan synchronously, and keep the optical path or phase change between adjacent OCT scans A-Scan constant. Therefore, the accuracy and speed of the deflection angle corresponding to each A-Scan of the flat glass 1201 are required to be high, so the motor 1203 needs to use a servo mechanism such as a galvanometer that can achieve rapid rotation and positioning.

[0072] The main modules and their functions of this embodiment are summarized as follows: 1) The posterior segment OCT sample arm module can obtain important parameters of the human eye structure such as retinal thickness; 2) The anterior segment OCT sample arm module can obtain OCT images of the cornea and the anterior and posterior surfaces of the lens, thereby obtaining important parameters of the human eye structure such as the anterior and posterior surface curvature of the cornea, corneal thickness, anterior chamber depth, lens thickness, and anterior and posterior surface curvature of the lens; 3) The anterior segment OCT sample arm module cooperates with the posterior segment OCT sample arm module to obtain important parameters of the human eye structure such as the axial length; 4) In this embodiment 1, the anterior and posterior segment OCT images can be obtained by rapidly switching the anterior segment and posterior segment of the eye for scanning imaging.

[0073] Summary of the main working principles:

[0074] 1) When detecting the anterior segment OCT, the Doppler frequency shift technology is used and the algorithm is used to increase the detection depth of the OCT system, and then combined with the posterior segment OCT to measure the axial length of the eye.

[0075] 2) By quickly switching the scan, measuring the corneal and retinal OCT images, the axial length of the eye is measured. Then the frequency is increased or the optical path is changed to achieve anterior segment panoramic OCT measurement, and then the lens panoramic measurement is measured.

[0076] Example 2

[0077] The optical path of the OCT system of Example 2 is as follows: Figure 4 shown.

[0078] Compared with Example 1, the flat glass 1201 and the motor 1203 are eliminated in Example 2, and the servo mechanism 2205 is used to drive the fiber collimator 1107 and the sample arm fiber head (not shown) so that the two move together as a whole. The servo mechanism 2205 changes the optical path length of the sample arm by translation, and cooperates with the optical path switching scanning device 1109 to perform scanning, so that the optical path or phase change between adjacent OCT scans A-Scan remains constant. The OCT signal obtained by this method is equivalent to introducing a Doppler frequency shift. The computer 1143 processes the OCT signal obtained by the scanning method, and through the de-imaging algorithm, it can obtain an OCT image that utilizes positive and negative frequency image data, thereby achieving the purpose of doubling the detection depth.

[0079] Similarly, the servo mechanism 2205 can also be installed in the reference arm, that is, it drives the reference arm optical path lens 1121 and the reference arm optical fiber head (not shown) so that the two move together as a whole. The servo mechanism 2205 changes the optical path length of the sample arm by translation, and cooperates with the optical path switching scanning device 1109 to scan, so that the optical path or phase change between adjacent OCT scans A-Scan remains constant. The OCT signal obtained by this method is equivalent to introducing a Doppler frequency shift.

[0080] The servo mechanism 2205 may be a voice coil motor or piezoelectric ceramics or other mechanical devices that can achieve rapid translation.

[0081] Example 3

[0082] The optical path of the OCT system of Example 3 is as follows: Figure 5 shown.

[0083] Compared with Example 1, an anterior segment OCT sample arm module of Example 3 introduces an anterior segment different depth tissue OCT imaging shutter device (hereinafter referred to as shutter device). The optical path switching scanning device 1109 and the anterior segment different depth tissue OCT imaging shutter device are controlled by a computer to realize optical path switching, thereby realizing OCT imaging of different depth parts of the human eye.

[0084] In this embodiment 3, the posterior segment sample arm module 130 remains unchanged.

[0085] Anterior Segment OCT Sample Arm Module

[0086] The anterior segment OCT imaging system of Example 3 is as follows Figure 6 shown.

[0087] The anterior segment sample arm module includes an optical path switching scanning device 1109, a first reflector 1501, a first lens 1503, a third reflector 1505, a fifth reflector 1507, a third lens 1509, a third beam splitter 1307, a front beam splitter 1309 (fifth beam splitter 1309), and an eyepiece objective lens 1311. The anterior segment sample arm module also includes an anterior chamber insertion lens 3601 and a flat glass 1201 for measuring the anterior chamber of the eye.

[0088] In this embodiment 3, the anterior segment OCT sample arm module can be used for panoramic OCT scanning imaging of the entire lens and anterior segment OCT scanning imaging of the anterior chamber.

[0089] Panoramic OCT scanning of the entire lens

[0090] When performing panoramic OCT scanning imaging of the entire lens, the light emitted from the fiber collimator 1107 passes through the flat glass 1201 and is reflected by the optical path switching scanning device 1109. At this time, the optical path switching scanning device 1109 is controlled by the computer 1143. After the light beam is reflected by the optical path switching scanning device 1109, it is successively reflected by the first reflector 1501, transmitted by the first lens 1503, and then reflected by the third reflector 1505 and the fifth reflector 1507, and then transmitted by the third lens 1509, transmitted by the third beam splitter 1307, and then reflected by the front beam splitter 1309 (fifth beam splitter 1309) to the eye lens 1311, and finally converged to the human eye lens through the human eye E. The detection beam of the anterior segment OCT imaging optical path system meets the OCT beam focusing on the human eye lens.

[0091] The optical path switching scanning device 1109 is controlled by the computer 1143 and is in a position to realize anterior segment OCT imaging. At this time, the optical path switching scanning device 1109 is in a position that makes the angle between the main optical axis of the incident light from the fiber collimator 1107 and the main optical axis of the reflected light be β.

[0092] In this embodiment, the anterior segment sample arm module is preferentially used for the entire lens panoramic OCT scanning imaging. At this time, the insertion mirror of the shutter device for OCT imaging of different depth tissues of the anterior segment, the anterior chamber insertion mirror 3601, is in a state of leaving the anterior segment OCT optical path. That is, when measuring the entire lens panoramic OCT scanning imaging, the detection light does not pass through the insertion mirror of the shutter device.

[0093] OCT scan of the anterior chamber

[0094] When performing anterior chamber OCT scanning imaging, the anterior chamber OCT sample arm optical path also includes an optical path switching scanning device 1109, a first reflector 1501, a first lens 1503, a third reflector 1505, anterior chamber insertion mirror 3601 of a shutter device, a fifth reflector 1507, a third lens 1509, a third beam splitter 1307, a front beam splitter 1309 (fifth beam splitter 1309), an eyepiece objective lens 1311 and flat glass 1201.

[0095] When performing anterior chamber OCT scanning imaging, the light emitted from the fiber collimator 1107 passes through the flat glass 1201 and is reflected by the optical path switching scanning device 1109. At this time, the optical path switching scanning device 1109 is controlled by the computer 1143. After being reflected by the optical path switching scanning device 1109, the light beam is successively reflected by the first reflector 1501, transmitted by the first lens 1503, and then by the third reflector 1505, through the anterior chamber insertion lens 3601, reflected by the fifth reflector 1507, and then transmitted through the third lens 1509, transmitted through the third beam splitter 1307, and then reflected by the pre-beam splitter 1309 (fifth beam splitter 1309) to the eyepiece objective lens 1311, and finally converged to the vicinity of the center of the anterior chamber of the human eye through the human eye E. The detection light beam of the anterior chamber OCT scanning imaging optical path system satisfies the OCT light beam focusing near the center of the anterior chamber of the human eye.

[0096] The optical path switching scanning device 1109 is controlled by the computer 1143 and is in a position to realize anterior segment OCT imaging. At this time, the optical path switching scanning device 1109 is in a position that makes the angle between the main optical axis of the incident light from the fiber collimator 1107 and the main optical axis of the reflected light be β.

[0097] At this time, the anterior chamber insertion mirror 3601 of the shutter device is inserted into the anterior chamber OCT optical path. That is, when the anterior chamber OCT scans and images, the detection light passes through the anterior chamber insertion mirror 3601. Therefore, the anterior chamber insertion mirror 3601 not only plays a role in adjusting the optical path, but also plays a role in changing the focus position of the anterior chamber OCT sample arm optical path. The position where it is inserted is only indicated in the figure. In principle, it can be inserted into other positions of the anterior chamber OCT sample arm optical path.

[0098] Compared with Example 1, the detection depth of the OCT system can be shallower and the cost can be lower. By adding frequency-adding technology, it can realize detection from the human cornea to the front surface of the human lens, that is, the anterior chamber of the eye, and can also realize OCT imaging of the entire lens. However, it cannot realize a single OCT scanning imaging from the cornea to the rear surface of the lens.

[0099] In Example 3, the OCT system can realize OCT scanning imaging of the entire anterior chamber and posterior segment of the eye by quickly switching the optical path of the anterior chamber and posterior segment OCT sample arm module. After the subject has measured the OCT images of the anterior chamber and posterior segment of the eye, the system probe does not need to be moved again or find a working position. By switching out the anterior chamber insertion mirror 3601 for measuring the anterior chamber of the eye, OCT scanning imaging of the lens of the eye to be measured can be realized.

[0100] In summary, the present invention provides an ophthalmic measurement system. Compared with the prior art, the present invention has the following main advantages:

[0101] The ophthalmic measurement system of the present invention realizes the rapid switching and scanning of the front and rear sections of the optical path by adding a frequency-adding device (Doppler frequency shift device) and working in coordination with the scanning device, allowing the system to obtain the parameters such as the front and rear section OCT images and the optical path adjustment amount, thereby measuring multiple optical parameters of the human eye. The Doppler frequency shift technology is introduced by adding a frequency-adding device, which enhances the detection depth of the frequency domain OCT system, and at the same time reasonably allocates cost control and signal-to-noise ratio under limited cost, thereby improving the imaging quality.

[0102] In addition, the system can quickly scan the anterior and posterior segments by quickly switching scans, almost reaching a quasi-real-time scanning speed, and can acquire dozens of images per second. This fast scanning speed helps to reduce the impact of irregular eye movement, thereby accurately measuring the axial length of the human eye. Images of the anterior and posterior segments can be acquired in one measurement process, which not only facilitates the doctor's operation, but also improves the diagnosis speed and the interactive experience between doctors and patients. At the same time, the system can detect key parameters such as the cornea, anterior chamber depth, axial length and corneal curvature in a single measurement.

[0103] The system of the present invention can meet the measurement requirements of different parts, obtain accurate data of important parameters of the human eye, and meet the needs of clinical diagnosis. It can be used to measure optical parameters related to the patient's eye, guide the selection of artificial lens parameters, examine the patient's eye, and guide the prevention and control of myopia in adolescents. The system can measure key ophthalmic parameters such as the axial length of the human eye, corneal curvature and its thickness, anterior chamber depth and lens thickness. By combining the rapid switching of the anterior and posterior segments and the Doppler frequency shift technology, the present invention realizes a panoramic OCT scan of the anterior segment, which can measure the axial length, anterior chamber depth, lens thickness and corneal thickness of the human eye, and finally realizes a comprehensive measurement of the optical parameters of the human eye.

[0104] Overall, the present invention has significant advantages in cost, speed, accuracy and versatility.

[0105] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. An ophthalmic measurement system based on a frequency loading device, comprising an OCT imaging module, wherein the OCT imaging module comprises an OCT light source, a reference arm module, an OCT sample arm module, a fiber coupler and a detector, wherein the OCT sample arm module comprises an optical path switching scanning device, a posterior segment OCT sample arm optical path and an anterior segment OCT sample arm optical path, wherein the detection light output by the fiber coupler is reflected at different angles by the optical path switching scanning device and then enters the posterior segment OCT sample arm optical path or the anterior segment OCT sample arm optical path respectively; characterized in that: It also includes a frequency loading device for changing the optical path during the OCT scanning process and keeping the optical path or phase change between adjacent OCT scans A-Scans constant, thereby introducing a Doppler frequency shift to the detection light.

2. The ophthalmic measurement system according to claim 1, wherein: The frequency loading device includes a motor and a flat glass, and the motor drives the flat glass to deflect or rotate to dynamically adjust the optical path; the optical path switching scanning device adjusts its scanning angle during the scanning process to cooperate with the deflection or rotation of the flat glass, and jointly acts on the detection light to keep the optical path or phase change between adjacent OCT scans A-Scan constant.

3. The ophthalmic measurement system according to claim 2, characterized in that: The motor drives the flat glass to deflect to a set angle, so that after the detection light is deflected by the flat glass, it will not hit the rotation center of the rotating reflective mirror of the optical path switching scanning device. The scanning angle change of the optical path switching scanning device during the scanning process is utilized to keep the optical path or phase change between adjacent OCT scans A-Scan constant.

4. The ophthalmic measurement system according to claim 2, wherein: The motor drives the flat glass to rotate, and scans synchronously with the optical path switching scanning device to generate a changed optical path, and keep the optical path or phase change between adjacent OCT scans A-Scan constant.

5. The ophthalmic measurement system according to claim 1, wherein: The frequency loading device includes a servo mechanism, and the OCT sample arm module includes a sample arm optical fiber head and an optical fiber collimator. The detection light enters the optical path switching scanning device from the sample arm optical fiber head through the optical fiber collimator. The optical fiber collimator and the sample arm optical fiber head are driven by the servo mechanism so that the two move together as a whole, changing the optical path length of the sample arm, and cooperating with the optical path switching scanning device to perform scanning, so that the optical path or phase change between adjacent OCT scans A-Scan remains constant.

6. The ophthalmic measurement system according to claim 1, wherein: The frequency loading device includes a servo mechanism, and the reference arm module includes a reference arm fiber head, a reference arm optical path lens and a reference arm reflector. The reference light is emitted from the reference arm fiber head through the reference arm optical path lens and hits the reference arm reflector, and then is reflected by the reference arm reflector and returns to the fiber coupler. The reference arm optical path lens and the reference arm fiber head are driven by the servo mechanism so that the two move together as a whole, changing the optical path length of the reference arm, and cooperating with the optical path switching scanning device to perform scanning so that the optical path or phase change between adjacent OCT scans A-Scan remains constant.

7. The ophthalmic measurement system according to any one of claims 1 to 6, characterized in that: The anterior chamber OCT sample arm optical path includes an anterior chamber measuring lens, which is configured to cut into or out of the optical path; the anterior chamber measuring lens is designed to cut into the optical path when performing anterior chamber OCT scanning imaging to guide the detection light beam to focus near the center of the anterior chamber of the eye; when performing panoramic OCT scanning imaging of the entire lens, the anterior chamber measuring lens is in a cut-out state.

8. The ophthalmic measurement system according to claim 7, characterized in that: The anterior segment OCT sample arm optical path includes a first reflector, a first lens, a third reflector, a fifth reflector, a third lens, a third beam splitter, a front beam splitter and an eyepiece objective lens. After the light beam is reflected by the optical path switching scanning device, it is successively reflected by the first reflector, transmitted by the first lens, and then reflected by the third reflector and the fifth reflector, and then transmitted by the third lens, transmitted by the third beam splitter, and then reflected by the front beam splitter to the eyepiece objective lens, and finally converged to the anterior segment of the human eye through the human eye; wherein, the anterior segment of the human eye chamber insertion lens can be inserted into the anterior segment OCT sample arm optical path.

9. The ophthalmic measurement system according to any one of claims 1 to 8, characterized in that: The optical path of the posterior segment OCT sample arm includes a light path module, a posterior segment and a gaze beam splitter, a refractive adjustment device, a third beam splitter, a front beam splitter and an eyepiece objective lens in sequence. After the light beam is reflected by the optical path switching scanning device, it passes through the light path module, and then is reflected by the posterior segment and the gaze beam splitter, passes through the refractive adjustment device, is reflected by the third beam splitter, and then is reflected by the front beam splitter to the eyepiece objective lens, and finally passes through the human eye to converge to the fundus of the human eye.

10. The ophthalmic measurement system according to any one of claims 1 to 9, characterized in that: Also included is a computer connected to the detector, which processes the interference signal introduced with the Doppler frequency shift and uses a de-imaging algorithm to obtain an OCT image using positive and negative frequency image data.

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