A corneal graft configuration measurement device using a grating projection method and its usage method

Abstract

The present invention discloses a corneal graft configuration measuring device and a using method thereof by the grating projection method, which relates to the technical field of corneal graft configuration measurement. The device includes a grating optical measurement component and an eyeball environment simulation component. The eyeball environment simulation component is an intraocular pressure bubbler, and the intraocular pressure bubbler includes a hydraulic cavity and an eyeball-mimicking rigid support. The eyeball-mimicking rigid support is arranged at the top of the hydraulic cavity. The grating optical measurement component includes a laser light source, a precision optical grating, a condenser lens, a transparent artificial corneal graft, a narrow-band filter, and an industrial camera. By adopting the above-mentioned corneal graft configuration measuring device and using method thereof by the grating projection method, the present invention solves the deficiencies of the prior art by using a transmissive measurement optical path, and can non-contact, real-time, high-precision, and low-cost measure the configuration evolution of the corneal graft under the standard intraocular pressure environment, simulate the surgical efficacy of corneal transplantation, and provide effective guidance for the optimization of corneal transplantation surgical plans in medical clinics.

Description

Technical Field

[0001] The present invention relates to the technical field of corneal graft configuration measurement, and in particular to a corneal graft configuration measurement device and a usage method using a grating projection method. Background Art

[0002] Corneal transplantation technology is the only means to treat corneal blindness, and its core treatment idea lies in replacing the diseased part of the cornea with a normal corneal graft. Since the optical performance of the cornea is directly related to the corneal surface configuration, the effect of corneal transplantation surgery depends on whether the corneal graft can maintain a good configuration. The corneal graft under service conditions is a heterogeneous soft material composite structure, and its configuration evolution is complex and difficult to predict. The thickness of the cornea is only about five hundred micrometers. How to accurately, conveniently and real-time measure the evolution of the surface configuration of the corneal graft in such a narrow space has become a major challenge in current research.

[0003] The corneal graft belongs to a typical transparent soft material, and its configuration evolves dynamically with the change of load and time. Therefore, it is very difficult to measure the configuration accurately and in real time. The existing research has the following problems:

[0004] (1) Existing reflection measurement methods such as corneal topographers can only measure the configuration of the upper surface of the cornea. When measuring a larger surface curvature, the reflection measurement optical path must be changed to an oblique axis optical path because it is difficult to collect the reflected light containing configuration information, and the oblique axis optical path has a high requirement for the depth of field of the measurement camera.

[0005] (2) Existing projection measurement methods such as speckle method and fluorescence profilometry will interfere with the state of the corneal graft, and a non-contact measurement method is required to eliminate the influence of the observation means.

[0006] (3) The corneal graft is under the action of long-term intraocular pressure during service, and it is necessary to maintain the corneal graft in a stable intraocular pressure environment during the observation process.

[0007] (4) The configuration evolution of the corneal graft has a high time correlation, and the existing configuration measurement devices cannot maintain long-term real-time monitoring.

[0008] In summary, due to the complexity of the service environment and material properties of the corneal graft, the configuration evolution after corneal graft suturing is a complex and dynamic process. However, the existing measurement instruments or measurement methods cannot realize the observation of the surface configuration evolution of the corneal graft in a standard intraocular pressure environment, and a new measurement instrument needs to be designed to meet the research requirements. Summary of the Invention

[0009] The object of the present invention is to provide a corneal graft configuration measuring device and a using method thereof by the grating projection method, to solve the problems raised in the above-mentioned background technology. By adopting a transmissive measurement optical path and analyzing the distortion information of the grating transmitted through the surface of the corneal graft, it is possible to measure the configuration evolution of the corneal graft surface in a non-contact, real-time, high-precision and low-cost manner, simulate the surgical efficacy of corneal transplantation, and provide effective guidance for optimizing the surgical plan of corneal transplantation in medical clinics.

[0010] To achieve the above object, the present invention provides a corneal graft configuration measuring device by the grating projection method, which includes a grating optical measurement component and an eyeball environment simulation component. The eyeball environment simulation component is an intraocular pressure bubbler, and the intraocular pressure bubbler includes a hydraulic cavity and an eyeball-like rigid support. The eyeball-like rigid support is arranged on the top of the hydraulic cavity and is communicated with the hydraulic cavity.

[0011] The grating optical measurement component includes a laser light source, a precision optical grating, a condenser lens, a transparent artificial corneal graft, a narrowband filter and an industrial camera.

[0012] Preferably, the industrial camera is arranged above the narrowband filter, the narrowband filter is arranged above the transparent artificial corneal graft, and the transparent artificial corneal graft is fixed on the upper surface of the eyeball-like rigid support through a hemispherical buckle.

[0013] Preferably, a plurality of condenser lenses are provided. The plurality of condenser lenses are clamped inside the hydraulic cavity, and the optical centers are located on the same straight line.

[0014] Preferably, the laser light source is arranged at the bottom of the hydraulic cavity, and a precision optical grating is arranged above the laser light source.

[0015] Preferably, one side of the hydraulic cavity is connected with a hydraulic pump through an infusion pipeline.

[0016] Preferably, the transparent artificial corneal graft is made of transparent hydrogel.

[0017] A using method of a corneal graft configuration measuring device by the grating projection method includes the following steps:

[0018] Step S1: Prepare the equipment;

[0019] Step S2: Load the corneal service environment and collect data;

[0020] Step S3: Process the data.

[0021] Preferably, the specific steps of the step S1 are as follows:

[0022] Step S11: Set up the grating projection optical path. From bottom to top, embed a laser light source, a precision optical grating, and a condenser lens into the hydraulic chamber of the intraocular pressure bubble instrument. Fix the transparent artificial cornea implant at the center of the rigid support of the artificial eyeball through a hemispherical buckle. Fix a narrowband filter and an industrial camera above the transparent artificial cornea implant through a backplane bracket, and ensure that the optical centers of the laser light source, the precision optical grating, the condenser lens, the transparent artificial cornea implant, the narrowband filter, and the industrial camera are located on the same vertical axis.

[0023] Step S12: Connect the industrial camera to the computer through a signal collector.

[0024] Preferably, the specific steps of step S2 are as follows:

[0025] Step S21: Inject artificial aqueous humor into the hydraulic pump and raise the pressure of the intraocular pressure bubble instrument to the standard physiological intraocular pressure through the hydraulic pump.

[0026] Step S22: Turn on the laser light source and adjust the height of the condenser lens and the relative positions between the condenser lenses.

[0027] Step S23: Collect data through the industrial camera. The collected data are the initial grating pattern and the distorted grating pattern after passing through the transparent artificial cornea implant. After the collection is completed, transmit the real-time data to the data processing unit in the computer through the signal collector.

[0028] Preferably, the specific steps of step S3 are as follows:

[0029] Step S31: After the data processing unit receives the real-time data, calculate the phase value of each pixel point through the phase shift method and obtain the continuous absolute phase through phase unwrapping.

[0030] Step S32: According to the phase value and the known system geometric relationship, calculate the three-dimensional coordinates on the surface of the transparent artificial cornea implant using the principle of triangulation.

[0031] Therefore, the corneal implant configuration measurement device and method using the above-mentioned grating projection method of the present invention have the following beneficial effects:

[0032] (1) The present invention adopts a transmissive grating back-projection measurement technology, which avoids the interference effect caused by the reflected light on the corneal surface in the reflective or projection measurement optical path, and can also solve the problem of uneven image clarity caused by the distance difference between the surface of the object to be measured and the camera.

[0033] (2) The designed bubble instrument support with an artificial eyeball structure of the present invention avoids the deformation of the corneal implant caused by excessive or improper boundary constraints during the measurement process, and the measured configuration change information has high fidelity.

[0034] (3) The configuration measurement method of the corneal graft in the present invention is non-contact, and the configuration evolution of the corneal graft will not be affected by the measurement method.

[0035] (4) In the present invention, the bubble generator can apply a pressure consistent with the true physiological intraocular pressure on the corneal specimen, and the corneal graft will not degenerate in a short time, which can meet the observation of the configuration evolution of the corneal graft.

[0036] (5) The present invention uses a high-density and high-resolution optical grating, which has high sensitivity to the deformation of the corneal configuration. Therefore, the accuracy of the measurement result is guaranteed to be at the sub-micron to micron level. At the same time, it is robust to changes in ambient light and the reflectivity of the object surface, enabling it to maintain good measurement effects in different environments.

[0037] (6) The grating projection method of the present invention is easy to be combined with an automated system to realize automated measurement and data processing, and is suitable for integrated applications in scientific research or industrial production.

[0038] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0039] Figure 1 It is a schematic structural diagram of an embodiment of a device and a use method for measuring the configuration of a corneal graft by the grating projection method of the present invention;

[0040] Figure 2 It is a schematic measurement principle diagram of an embodiment of a device and a use method for measuring the configuration of a corneal graft by the grating projection method of the present invention;

[0041] Figure 3 It is a data processing flow chart of an embodiment of a device and a use method for measuring the configuration of a corneal graft by the grating projection method of the present invention;

[0042] Reference numerals: 1, industrial camera; 2, narrow-band filter; 3, rigid support imitating the eyeball; 4, hydraulic cavity; 5, condenser lens; 6, precision optical grating; 7, laser light source; 8, transparent artificial corneal graft; 9, hydraulic pump; 10, optical path light ray. Detailed Embodiments

[0043] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0044] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the field to which the present invention pertains. The terms "first", "second" and similar terms used in the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "upper", "lower", "left" and "right" are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0045] Embodiment

[0046] Please refer to Figures 1-3 , to achieve the above object, the present invention provides a corneal graft configuration measuring device using a grating projection method, including a grating optical measuring component and an eyeball environment simulation component. The eyeball environment simulation component is an intraocular pressure bubble instrument, which includes a hydraulic chamber 4 and an eyeball-like rigid support 3, and can restore the physiological position of the transparent artificial corneal graft 8 under service conditions while providing a standard intraocular pressure. The eyeball-like rigid support 3 is arranged on the top of the hydraulic chamber 4 and is connected to the hydraulic chamber 4, and the connection between the eyeball-like rigid support 3 and the hydraulic chamber 4 is a closed rigid connection to ensure hydraulic stability during the test.

[0047] One side of the hydraulic chamber 4 is connected to a hydraulic pump 9 through an infusion pipeline. The hydraulic pump 9 is connected to the liquid inside the hydraulic chamber 4 through the infusion pipeline, and a control panel is provided on the hydraulic pump 9, which can output or regulate the hydraulic pressure inside the hydraulic chamber 4 in real time.

[0048] The grating optical measuring component includes a laser light source 7, a precision optical grating 6, a condenser lens 5, a transparent artificial corneal graft 8, a narrowband filter 2 and an industrial camera 1.

[0049] The industrial camera 1 is arranged above the narrowband filter 2. The narrowband filter 2 allows light signals within the same wavelength range as the laser light source 7 to pass through, while blocking or absorbing light in other wavelength ranges, reducing the external noise when the industrial camera 1 collects image signals and improving the measurement accuracy. A GigE interface is provided on the industrial camera 1, which can be connected to a computer through an RJ45 network cable and supports a signal transmission speed of gigabit level, ensuring the real-time nature of the measurement.

[0050] The narrowband filter 2 is arranged above the transparent artificial cornea implant 8. A sample placement hole with a diameter slightly smaller than that of the transparent artificial cornea implant 8 is opened at the central top of the eye-like rigid support 3. During the test, the transparent artificial cornea implant 8 is fixed on the sample placement hole through a hemispherical snap buckle that fits with the eye-like rigid support 3, ensuring that the transparent artificial cornea implant 8 is only restricted by edge constraints, so as not to generate surface wrinkles. The transparent artificial cornea implant 8 is made of transparent hydrogel and has material properties similar to those of the cornea and good biocompatibility.

[0051] Three condenser lenses 5 are provided. The three condenser lenses 5 are clamped inside the hydraulic chamber 4, and their optical centers are located on the same straight line. The three condenser lenses 5 are integrated inside the hydraulic chamber 4 through slots with adjustable positions. During the measurement, the height of the condenser lenses 5 can be adjusted to ensure that the optical path does not spread divergently in all directions, so that the precision optical grating 6 can be projected onto the transparent artificial cornea implant 8 with high brightness without distortion.

[0052] The laser light source 7 is arranged at the bottom of the hydraulic chamber 4, and the precision optical grating 6 is arranged above the laser light source 7. The laser light source 7 and the precision optical grating 6 are integrated at the bottom of the hydraulic chamber 4 through reserved slots. The size of the precision optical grating 6 is the same as that of the laser light source 7, so it can completely cover the laser light source 7, ensuring that the projection of the precision optical grating 6 during the test can be vertically projected onto the transparent artificial cornea implant 8.

[0053] The measurement principle of the above device is as Figure 2 shown. The light rays emitted by the laser light source 7 pass through the precision optical grating 6 to form the optical path light rays 10, pass through the transparent artificial cornea implant 8, and then form a grating pattern through the data acquisition of the industrial camera 1.

[0054] The usage method of the corneal implant configuration measurement device using the above grating projection method specifically includes the following steps:

[0055] Step S1: Prepare the equipment. In this embodiment, the human eye intraocular pressure simulation component and the grating optical measurement component can measure the transparent artificial cornea implant 8 in a high-fidelity intraocular pressure and solution environment. At the same time, the grating back-projection method used ensures high-precision, low-cost, and real-time measurement.

[0056] Disinfect the surfaces of each functional module to ensure a sterile environment. The specific steps for equipment preparation after disinfection are as follows:

[0057] Step S11: Set up the grating projection optical path. Embed the laser light source 7, precision optical grating 6, and condenser lens 5 into the hydraulic chamber 4 of the intraocular pressure bubble instrument from bottom to top. Fix the transparent artificial cornea implant 8 at the center of the eye-like rigid support 3 through a hemispherical buckle. Fix the narrowband filter 2 and industrial camera 1 above the transparent artificial cornea implant 8 through a backplane bracket (not shown in the figure), and make the optical centers of the laser light source 7, precision optical grating 6, condenser lens 5, transparent artificial cornea implant 8, narrowband filter 2, and industrial camera 1 lie on the same vertical axis.

[0058] Step S12: Connect the industrial camera 1 to the computer through a signal collector.

[0059] Step S2: Perform corneal service environment loading and data acquisition. The specific steps are as follows:

[0060] Step S21: Inject artificial aqueous humor into the hydraulic pump 9, and raise the pressure of the intraocular pressure bubble instrument to the standard physiological intraocular pressure through the hydraulic pump 9.

[0061] Step S22: Turn on the laser light source 7, adjust the height of the condenser lens 5 and the relative positions among the three condenser lenses 5 to ensure that the projection of the precision optical grating 6 can be clearly seen from directly above the intraocular pressure bubble instrument.

[0062] Step S23: Perform data acquisition through the industrial camera 1. The acquired data is the initial grating pattern and the distorted grating pattern after passing through the transparent artificial cornea implant 8. After the acquisition is completed, transmit the real-time data to the data processing unit in the computer through the signal collector.

[0063] Step S3: Perform data processing. The specific steps are as follows:

[0064] Step S31: After the data processing unit receives the real-time data, preprocess the captured images, including noise reduction, contrast enhancement, distortion correction, etc., to improve the accuracy of subsequent phase calculation. Calculate the phase value of each pixel point through the phase shift method. Since the calculated phase value is usually wrapped within the range of 0 - 2π, phase unwrapping is required to obtain a continuous absolute phase value.

[0065] Step S32: According to the phase value and the known system geometric relationship (usually obtained through system calibration, including the relative position, focal length, grating period, etc. between the industrial camera 1 and the projection device), use the triangulation principle to calculate the three-dimensional coordinates on the surface of the transparent artificial cornea implant 8. Optimize and correct the calculated three-dimensional data to eliminate possible errors and artifacts, and improve the accuracy and reliability of the measurement results. Output the processed three-dimensional data for further visualization modeling and reconstruction of the corneal implant configuration.

[0066] Therefore, the present invention adopts the above corneal graft configuration measuring device and usage method of a grating projection method, and uses a transmissive measurement optical path to solve the deficiencies in the prior art. It can non-contact, real-time, high-precision and low-cost measure the configuration evolution of corneal grafts in a standard intraocular pressure environment, simulate the surgical efficacy of corneal transplantation, and provide effective guidance for the optimization of corneal transplantation surgical plans in medical clinics.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A corneal graft configuration measuring device using the grating projection method, characterized in that: It includes a grating optical measurement component and an eyeball environment simulation component. The eyeball environment simulation component is an intraocular pressure bubble instrument, which includes a hydraulic chamber and an eyeball-like rigid support. The eyeball-like rigid support is arranged on the top of the hydraulic chamber and is connected to the hydraulic chamber; The grating optical measurement component includes a laser light source, a precision optical grating, a condenser lens, a transparent artificial cornea implant, a narrowband filter, and an industrial camera; The industrial camera is arranged above the narrowband filter, the narrowband filter is arranged above the transparent artificial cornea implant, and the transparent artificial cornea implant is fixed on the upper surface of the eyeball-like rigid support through a hemispherical buckle; A plurality of condenser lenses are provided, and the plurality of condenser lenses are clamped inside the hydraulic chamber, and the optical centers are located on the same straight line; The laser light source is arranged at the bottom of the hydraulic chamber, and a precision optical grating is arranged above the laser light source. The laser light source and the precision optical grating are integrated at the bottom of the hydraulic chamber through a reserved groove. The size of the precision optical grating is the same as that of the laser light source and can completely cover the laser light source to ensure that the projection of the precision optical grating can be vertically projected onto the transparent artificial cornea implant during testing.

2. The corneal graft configuration measuring device using the grating projection method according to claim 1, wherein: One side of the hydraulic chamber is connected to a hydraulic pump through an infusion pipeline.

3. The corneal graft configuration measuring device using the grating projection method according to claim 2, characterized in that: The transparent artificial cornea implant is made of transparent hydrogel.

4. A method for using the corneal graft configuration measuring device of the grating projection method according to claim 3 above, characterized in that, It includes the following steps: Step S1: Prepare the equipment; The specific steps of the said step S1 are as follows: Step S11: Build the grating projection optical path. From bottom to top, embed the laser light source, the precision optical grating, and the condenser lens into the hydraulic chamber of the intraocular pressure bubble instrument. Fix the transparent artificial cornea implant at the center of the eyeball-like rigid support through a hemispherical buckle. Fix the narrowband filter and the industrial camera above the transparent artificial cornea implant through a backplane bracket, and make the optical centers of the laser light source, the precision optical grating, the condenser lens, the transparent artificial cornea implant, the narrowband filter, and the industrial camera be on the same vertical axis; Step S12: Connect the industrial camera to the computer through a signal collector; Step S2: Load the corneal working environment and collect data; Step S3: Process the data.

5. The usage method of a corneal graft configuration measuring device using the grating projection method according to claim 4, characterized in that, The specific steps of the said step S2 are as follows: Step S21: Inject artificial aqueous humor into the hydraulic pump, and raise the pressure of the intraocular pressure bubble instrument to the standard physiological intraocular pressure through the hydraulic pump; Step S22: Turn on the laser light source and adjust the height of the condenser lens and the relative positions between the condenser lenses; Step S23: Collect data through the industrial camera. The collected data are the initial grating pattern and the distorted grating pattern after passing through the transparent artificial cornea implant. After the collection is completed, transmit the real-time data to the data processing unit in the computer through the signal collector.

6. The method of using a corneal graft configuration measuring device by the grating projection method according to claim 5, characterized in that, The specific steps of the said step S3 are as follows: Step S31: After the data processing unit receives the real-time data, calculate the phase value of each pixel point through the phase shift method and obtain the continuous absolute phase through unwrapping; Step S32: According to the phase value and the known system geometric relationship, calculate the three-dimensional coordinates on the surface of the transparent artificial cornea implant by using the principle of triangulation.

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