Repeatability methods, apparatus, equipment and storage media for corneal topography measurements
By using the area-weighted evaluation method, the problems of insufficient local representativeness and high cost in the repeatability evaluation of corneal topography measurements were solved, achieving a more comprehensive and robust evaluation of equipment performance and reducing evaluation costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG MEDICAL DEVICE INSPECTION INST (STATE FOOD & DRUG ADMINISTRATION HANGZHOU MEDICAL DEVICE QUALITY SUPERVISION & INSPECTION CENT)
- Filing Date
- 2026-01-19
- Publication Date
- 2026-06-02
Smart Images
Figure CN122123636A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of corneal topography testing technology, and in particular to a method, apparatus, equipment and storage medium for evaluating the repeatability of corneal topography measurements using area weighting values. Background Technology
[0002] Corneal topography is a key diagnostic device in the field of modern optometry. The accuracy and repeatability of its measurement results are crucial for optometry, preoperative planning, and postoperative evaluation.
[0003] Currently, the domestic industry commonly uses a method of performing a small number of continuous measurements (e.g., 5 times) on the same test surface and assessing repeatability by calculating the standard deviation of multiple measurements at a single measurement point. The final repeatability index is usually defined as the maximum value among the standard deviations of all measurement points. This method has shortcomings: First, it uses a local, worst-case performance point to represent the overall performance of the entire device in the corneal region, which is unfair. Second, this method is extremely sensitive to gross errors or random noise; the appearance of a single outlier can lead to a misjudgment of the overall device performance.
[0004] Internationally, the repeatability of corneal topography is evaluated by measuring 20 real corneal samples. However, while the international standard testing method, which measures real corneal samples, provides reliable results in a short time, it is costly in terms of human resources and involves a cumbersome process, making it difficult to promote its application in routine quality control.
[0005] Therefore, there is an urgent need in the field for a new method for evaluating the repeatability of corneal topography measurements that can comprehensively reflect the performance of the equipment, has anti-interference capabilities, and is easy to implement. Summary of the Invention
[0006] In view of this, the present invention proposes a method, apparatus, device and storage medium for measuring repeatability of corneal topography. By using area weight values to evaluate the repeatability of corneal topography measurements, the local repeatability of each measurement point is synthesized according to its spatial representativeness (area weight), thereby obtaining a global comprehensive evaluation index.
[0007] In a first aspect, to achieve the above objective, the present invention provides a method for repeatability measurement using a corneal topography instrument, comprising: Data acquisition: Multiple independent and repeated measurements were performed on the same test surface using a corneal topography instrument to obtain multiple sets of corneal topography data; Single-point repeatability calculation: Based on the multiple sets of corneal topography data, calculate the single-point standard deviation of each measurement point in the measurement area to characterize the single-point repeatability of each measurement point; Area weighting: Assigning an area weight value representing the spatial representativeness of each measurement point; and Overall repeatability assessment: The overall measurement repeatability index of the corneal topography instrument is obtained by weighting the standard deviation of each measurement point and its corresponding area weight value.
[0008] Preferably, in the step "single-point repeatability calculation", the single-point standard deviation s i The result was obtained using the range method.
[0009] Preferably, in the step "area weight allocation", the area weight value The calculation formula is: Where n is the total number of measurement points, i is the measurement point number, and r i Let be the radius of measurement point i.
[0010] Preferably, the step "overall repeatability assessment" further includes: The formula for calculating the area-weighted, repeatable average value M of a single point is: Where n is the total number of measurement points, s represents the area weight value. i Let i be the single-point standard deviation of the measurement point i; The formula for calculating the overall measurement standard deviation S after area weighting is: The overall measurement standard deviation S, weighted by k times the area, is used as the overall measurement repeatability index, where k is a predefined coefficient; Preferably, the value of k is 2.
[0011] Preferably, in the step "data acquisition", the number of repeated measurements N satisfies 3 ≤ N ≤ 9; the test surface is a spherical test surface or a toroidal test surface that simulates the corneal topography.
[0012] Preferably, the measurement points are selected in a polar coordinate system, and the selected measurement points are located in a region with a diameter of 1 mm to 6 mm, with at least 6 different radial distances selected.
[0013] Preferably: If the test surface is a spherical test surface, at least 6 distances shall be selected in the radial direction, and the angle interval shall not be greater than 45°. If the test surface is a toroidal test surface, then at least 6 distances should be selected in the radial direction, and the angle positions should be selected in the two principal meridian directions.
[0014] Secondly, to achieve the above objectives, the present invention also provides a corneal topography measurement repeatability device, characterized in that it comprises: The data acquisition module is used to perform multiple independent and repeated measurements on the same test surface using a corneal topography instrument to obtain multiple sets of corneal topography data; The single-point repeatability calculation module is used to calculate the single-point standard deviation of each measurement point in the multiple measurement points within the measurement area based on the multiple sets of corneal topography data, so as to characterize the single-point repeatability of each measurement point. An area weight allocation module is used to assign an area weight value representing the spatial representativeness of each measurement point; and The overall repeatability assessment module is used to perform weighted calculations based on the single-point standard deviation of each measurement point and its corresponding area weight value to obtain the overall measurement repeatability index of the corneal topography instrument.
[0015] Thirdly, to achieve the above objectives, the present invention also provides an electronic device, comprising: One or more processors; Memory for storing one or more programs of the processor; When the one or more programs are executed by the one or more processors, the one or more processors perform the method described in any of the first aspects.
[0016] Fourthly, to achieve the above objectives, the present invention also provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in any one of the first aspects.
[0017] The area weighting values used in this invention are theoretically based on the evaluation requirements for the measurement accuracy of corneal topography instruments in the currently effective international standard ISO 19980:2021 and industry standard YY / T 0787-2024. These standards require that the spatial distribution and representativeness of measurement points throughout the corneal region be considered when evaluating equipment accuracy. By assigning a weight value proportional to the area of the region influencing each measurement point, the differences in the contribution of different regions to the measurement accuracy evaluation can be more accurately reflected. Based on the above principle, this invention introduces the area weighting values required for measurement accuracy into the measurement repeatability evaluation method, effectively transforming non-uniform sampling data into uniform sampling results, thereby achieving a scientific evaluation of the measurement repeatability of the entire corneal region.
[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. More comprehensive evaluation: It integrates information from all measurement points, avoiding the one-sidedness of the "maximum value method" and can truly reflect the overall performance of the device in the entire corneal area.
[0019] 2. Strong anti-interference ability: The weighted averaging process itself has a smoothing and filtering effect, which can effectively suppress the negative impact of individual gross errors or noise points on the final result, making the evaluation results more robust.
[0020] 3. Low implementation cost: It only requires selecting one test surface and performing several measurements to complete the process. The process is simple and the cost is far lower than that of international standard solutions.
[0021] 4. High degree of digitalization: It is automatically executed through software modules integrated into the corneal topography instrument and through evaluation software programs loaded and run on computer devices. It is very suitable for embedding in device software for factory inspection, periodic calibration and rapid performance comparison. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the implementation process of an embodiment of the corneal topography measurement repeatability method of the present invention; Figure 2 This is a distribution diagram of the measurement points on the spherical test surface in Example 1; Figure 3 This is a distribution diagram of measurement points on the toroidal surface test surface in Example 2; Figure 4 This is a schematic diagram of an optional hardware architecture for the electronic device of the present invention; Figure 5 This is a schematic diagram of the program modules of an embodiment of the corneal topography measurement repeatability device in the electronic device of the present invention.
[0023] Figure label: The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.
[0025] It should be noted that the descriptions involving "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.
[0026] It should be further noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.
[0027] First, this invention proposes a method for repeatability measurement using a corneal topography instrument.
[0028] See Figure 1 The diagram shown is a schematic flowchart of an embodiment of the corneal topography measurement repeatability method of the present invention. In this embodiment, according to different needs, Figure 1 The execution order of the steps in the flowchart shown can be changed, and some steps can be omitted.
[0029] Step S1, Data Acquisition: Multiple independent and repeated measurements are performed on the same test surface using a corneal topography instrument to obtain multiple sets of corneal topography data.
[0030] Preferably, in the step "data acquisition", the number of repeated measurements N satisfies 3 ≤ N ≤ 9; the test surface is a spherical test surface or a toroidal test surface that simulates the corneal topography.
[0031] Furthermore, the measurement points are selected in a polar coordinate system, and the selected measurement points are located within a region with a diameter of 1 mm to 6 mm, with at least 6 different radial distances selected.
[0032] If the test surface is a spherical test surface, at least six distances should be selected radially, with an angular interval of no more than 45°. See also... Figure 2The diagram shows the distribution of measurement points on the spherical test surface in Example 1. Polar coordinates were used to select the measurement sample points. Six radial distances were selected with radii of 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, and 3.0mm, with angular intervals of 45°. This corresponds to azimuth angles of 0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°, and 360°, totaling 48 sample points. Six concentric circles represent six different radial distances, eight line segments with arrows originating from the center of the circles represent eight azimuths, and the intersections of the six circles and the eight line segments constitute the 48 sample points.
[0033] If the test surface is a toroidal surface, at least six distances should be selected radially, and the angular positions should be selected along the two principal meridians. See also... Figure 3 The diagram shows the distribution of measurement points on the toroidal surface test surface in Example 2. Measurement sample points were selected using a polar coordinate system. Six radial distances were selected, with radii of 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, and 3.0mm, and angular intervals of 90°, corresponding to azimuth angles of 0°, 90°, 180°, and 270°, for a total of 24 sample points. The six concentric circles represent six different radial distances, the four line segments with arrows originating from the center of the circles represent four azimuths, and the intersections of the six circles and the four line segments constitute the 24 sample points.
[0034] Step S2, Single-point repeatability calculation: Based on the multiple sets of corneal topography data, calculate the single-point standard deviation of each measurement point in the multiple measurement points within the measurement area to characterize the single-point repeatability of each measurement point.
[0035] Preferably, in the step "single-point repeatability calculation", the single-point standard deviation s i The standard deviation is calculated using the range method. In this embodiment, for each measurement sample point i within the measurement area, the standard deviation of that point is calculated using the range method based on data from N measurements. The standard deviation is used to characterize the single-point repeatability of the point. In this embodiment, N is set to 5. Preferred methods are to select measurement sample points on a polar coordinate system. Within a region of 1mm ≤ diameter ≤ 6mm, for spherical test surfaces, at least 6 radial distances are selected, with an angle interval not exceeding 45°; for toroidal test surfaces, at least 6 radial distances are selected, with the angle positions corresponding to the two principal meridian directions.
[0036] Step S3, Area Weight Allocation: Assign an area weight value representing the spatial representativeness of each measurement point. In this embodiment, an area weight value ω is assigned to each measurement point i. i This weight value ensures that the sample points are sampled equally and uniformly.
[0037] Preferably, for a polar coordinate system, the area weight value The calculation formula is: Where n is the total number of measurement points, i is the measurement point index (a measurement point in the array), and r i Let n be the radius of measurement point i. In Example 1, n=48, and in Example 2, n=24.
[0038] Step S4, Overall repeatability assessment: The overall measurement repeatability index of the corneal topography instrument is obtained by weighting the single-point standard deviation of each measurement point and its corresponding area weight value.
[0039] Preferably, in this embodiment, step S4 "overall repeatability assessment" further includes: Step S41, calculate the area-weighted single-point repeatability average M, the formula is: Where n is the total number of measurement points, s represents the area weight value. i Let be the single-point standard deviation of measurement point i.
[0040] Step S42, calculate the overall measurement standard deviation S after area weighting, using the following formula: Step S43, outputting the repeatability result of the corneal topography measurement: the overall measurement standard deviation S, weighted by k times the area, is used as the overall measurement repeatability index, where k is a predefined coefficient. Preferably, the value of k is 2. In this embodiment, the 2S value is used to characterize the repeatability of the corneal topography measurement, and the output corneal topography measurement repeatability is 2S.
[0041] The following two specific embodiments (Example 1 and Example 2) illustrate the specific implementation process of the present invention.
[0042] Example 1: Five repeated measurements of a spherical test surface The implementation process is as follows: Step 1: The operator aligns a commercial corneal topography instrument with a standard spherical test surface with a corneal refractive power of 42.46D for measurement. After the measurement is completed, the test surface is removed and then repositioned. This process is repeated 5 times independently and the data is saved.
[0043] Step 2: Select measurement sample points using a polar coordinate system. Select 6 radial distances with radii of 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, and 3.0mm, with an angular interval of 45°. That is, the azimuth angles are 0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°, and 360°, for a total of 48 sample points.
[0044] For each measurement sample point i, the standard deviation of that point is calculated using the range method based on the data from 5 measurements. The standard deviation is used to characterize the single-point repeatability of a point. The calculation formula is: Where R is the range and C is the range coefficient. For N=5, C=2.33.
[0045] Step 3: Area weight allocation: Assign an area weight value ωi to each measurement point i. This weight value ensures that the sample points are sampled equally and uniformly.
[0046] For polar coordinates The calculation formula is: Where n is the total number of measurement points (n=48), and i is a measurement point in the array. It is the radius of measurement point i.
[0047] Step 4: Calculate the average of the area-weighted single-point repeatability: using the following formula Calculate the average of the single-point repeatability after area weighting, where n is the total number of measurement points.
[0048] Step 5: Calculate the overall measurement standard deviation after area weighting: using the formula Calculate the overall measurement standard deviation after area weighting.
[0049] Step 6: Output of corneal topography measurement repeatability results: The repeatability of corneal topography measurement is characterized by the 2S value, and the output of corneal topography measurement repeatability is 2S.
[0050] Detailed test data for Example 1 are shown in Table 1.
[0051] Step 1, Data Acquisition: The results are shown in the "Measured Values of Corneal Refractive Power" column in Table 1; Step 2, Single-point repeatability calculation: The results are shown in the "Single-point standard deviation" column of Table 1; Step 3, Area weight allocation: The results are shown in the "Area weight value" column of Table 1; Based on the above process data, perform the following steps: Step 4, calculate the average value of single-point repeatability after area weighting: the result is M=0.05D; Step 5, Calculate the overall measurement standard deviation after area weighting: The result is S=0.04D; Step 6, Output of corneal topography measurement repeatability results: The final report shows that the corneal topography measurement repeatability is 0.08D.
[0052] Table 1 Detailed test data from Example 1 Comparative analysis: Current industry-standard methods report corneal topography measurement repeatability as 0.30D (maximum single-point standard deviation), while the method of this invention reports a repeatability of 0.08D. Clearly, 0.08D more accurately reflects the device's stable performance in most important areas, while 0.30D significantly overestimates the error due to a single outlier, potentially leading to misjudgment of a well-performing device. This fully demonstrates the superiority and practicality of the method of this invention.
[0053] Example 2: Five repeated measurements of the toroidal surface test surface The implementation process is as follows: Step 1: The operator aligns a commercial corneal topography instrument with a standard torus test surface for measurement (the corneal refractive power of the two meridians is 42.19D and 44.41D respectively). After the measurement is completed, the test surface is removed, and the process is repeated for a total of 5 independent measurements, and the data is saved.
[0054] Step 2: Select measurement sample points using polar coordinates. Select 6 radial distances with radii of 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, and 3.0mm, with angular intervals of 90°, i.e., azimuth angles of 0°, 90°, 180°, and 270°, for a total of 24 sample points.
[0055] For each measurement sample point i, the standard deviation of that point is calculated using the range method based on the data from 5 measurements. The standard deviation is used to characterize the single-point repeatability of a point. The calculation formula is: Where R is the range and C is the range coefficient. For N=5, C=2.33. Step 3: Area weight allocation: Assign an area weight value ωi to each measurement point i. This weight value ensures that the sample points are sampled equally and uniformly.
[0056] For polar coordinates The calculation formula is: Where n is the total number of measurement points (n=24), and i is a specific measurement point in the array. It is the radius of measurement point i.
[0057] Step 4: Calculate the average of the area-weighted single-point repeatability: using the formula Calculate the average of the single-point repeatability after area weighting, where n is the total number of measurement points.
[0058] Step 5: Calculate the overall measurement standard deviation after area weighting: using the formula Calculate the overall measurement standard deviation after area weighting.
[0059] Step 6: Output of corneal topography measurement repeatability results: The repeatability of corneal topography measurement is characterized by the 2S value, and the output of corneal topography measurement repeatability is 2S.
[0060] Detailed test data for Example 2 are shown in Table 2.
[0061] Step 1, Data Acquisition: The results are shown in the "Measured Corneal Refractive Power (D)" column of Table 2; Step 2, Single-point repeatability calculation: The results are shown in the "Single-point standard deviation" column of Table 2; Step 3, Area weight allocation: The results are shown in the "Area weight value" column of Table 2; Based on the above process data, perform the following steps: Step 4, calculate the average value of single-point repeatability after area weighting: the result is M=0.05D; Step 5, Calculate the overall measurement standard deviation after area weighting: The result is S=0.06D; Step 6, Output of corneal topography measurement repeatability results: The final report shows that the corneal topography measurement repeatability is 0.12D.
[0062] Table 2 Detailed test data in Example 2 Comparative analysis: Current industry-standard methods report corneal topography measurement repeatability as 0.30D (i.e., the maximum single-point standard deviation), while the method of this invention reports a repeatability of 0.12D. Clearly, 0.12D more accurately reflects the device's stable performance in most important areas, while 0.30D significantly overestimates the error due to a single outlier, potentially leading to misjudgment of a well-performing device. This fully demonstrates the superiority and practicality of the method of this invention.
[0063] Through the above steps S1-S4, the corneal topography measurement repeatability method proposed in this invention uses area weighting to evaluate the repeatability of corneal topography measurements. It synthesizes the local repeatability of each measurement point according to its spatial representativeness (area weight), thereby obtaining a more scientific and comprehensive overall repeatability index.
[0064] See Figure 4 The diagram shown is a schematic of an optional hardware architecture for the electronic device 2 of the present invention. In this embodiment, the electronic device 2 may include, but is not limited to, a memory 21, a processor 22, and a network interface 23 that can communicate with each other via a system bus. It should be noted that... Figure 4 Only an electronic device 2 with components 21-23 is shown; however, it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.
[0065] The electronic device 2 can be a rack server, blade server, tower server or cabinet server or other computing device. The electronic device 2 can be an independent server or a server cluster composed of multiple servers.
[0066] The memory 21 includes at least one type of readable storage medium, including flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 21 may be an internal storage unit of the electronic device 2, such as the hard disk or memory of the electronic device 2. In other embodiments, the memory 21 may also be an external storage device of the electronic device 2, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the electronic device 2. Of course, the memory 21 may include both the internal storage unit and the external storage device of the electronic device 2. In this embodiment, the memory 21 is typically used to store the operating system and various application software installed on the electronic device 2, such as the program code of the corneal topography measurement repeatability device 20. In addition, the memory 21 can also be used to temporarily store various types of data that have been output or will be output.
[0067] In some embodiments, the processor 22 may be a central processing unit (CPU), controller, microcontroller, microprocessor, or other data processing chip. The processor 22 is typically used to control the overall operation of the electronic device 2, such as performing control and processing related to data interaction or communication with the electronic device 2. In this embodiment, the processor 22 is used to run program code stored in the memory 21 or process data, for example, to run the corneal topography measurement repeatability device 20.
[0068] The network interface 23 may include a wireless network interface or a wired network interface, which is typically used to establish communication connections between the electronic device 2 and other electronic devices. For example, the network interface 23 is used to connect the electronic device 2 to an external data platform via a network, establishing a data transmission channel and communication connection between the electronic device 2 and the external data platform. The network may be an intranet, the Internet, Global System for Mobile Communication (GSM), Wideband Code Division Multiple Access (WCDMA), 4G network, 5G network, Bluetooth, Wi-Fi, or other wireless or wired networks.
[0069] See Figure 5 The diagram shown is a program block diagram of an embodiment of the corneal topography measurement repeatability device 20 in the electronic device 2 of the present invention. In this embodiment, the corneal topography measurement repeatability device 20 can be divided into one or more program modules, which are stored in the memory 21 and executed by one or more processors (in this embodiment, processor 22) to complete the present invention. For example, in Figure 5 In this invention, the corneal topography repeatability measurement device 20 can be divided into a data acquisition module 201, a single-point repeatability calculation module 202, an area weight allocation module 203, and an overall repeatability evaluation module 204. The program module referred to in this invention is a series of computer program instruction segments capable of performing specific functions, and is more suitable than a program for describing the execution process of the corneal topography repeatability measurement device 20 in the electronic device 2. The functions of each program module 201-204 will be described in detail below.
[0070] The data acquisition module 201 is used to perform multiple independent and repeated measurements on the same test surface using a corneal topography instrument to obtain multiple sets of corneal topography data. The specific functions of the data acquisition module 201 are described in step S1 and will not be repeated here.
[0071] The single-point repeatability calculation module 202 is used to calculate the single-point standard deviation of each measurement point in the measurement area based on the multiple sets of corneal topography data, so as to characterize the single-point repeatability of each measurement point. The specific function of the single-point repeatability calculation module 202 is described in step S2 and will not be repeated here.
[0072] The area weight allocation module 203 is used to assign an area weight value representing the spatial representativeness of each measurement point. The specific function of the area weight allocation module 203 is described in step S3 and will not be repeated here.
[0073] The overall repeatability assessment module 204 is used to perform weighted calculations based on the single-point standard deviation of each measurement point and its corresponding area weight value to obtain the overall measurement repeatability index of the corneal topography instrument. The specific functions of the overall repeatability assessment module 204 are described in step S4 and will not be repeated here.
[0074] Through the above-mentioned program modules 201-204, the corneal topography measurement repeatability device 20 proposed in this invention uses the method of evaluating the measurement repeatability of corneal topography by adopting area weight values, and synthesizes the local repeatability of each measurement point according to its spatial representativeness (area weight), thereby obtaining a more scientific and comprehensive overall repeatability index.
[0075] Furthermore, to achieve the above objectives, the present invention also provides a computer-readable storage medium (such as ROM / RAM, magnetic disk, optical disk) storing a corneal topography measurement repeatability device 20, which can be executed by at least one processor 22 to perform the steps of the corneal topography measurement repeatability method as described above.
[0076] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.
[0077] The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but this does not limit the scope of the invention. The sequence numbers of the embodiments described above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. Furthermore, although a logical order is shown in the flowcharts, in some cases, the steps shown or described may be performed in a different order than that shown here.
[0078] Those skilled in the art can implement the present invention in various modifications without departing from its scope and essence. For example, a feature of one embodiment can be used in another embodiment to obtain yet another embodiment. Similarly, any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are also included within the patent protection scope of the present invention.
Claims
1. A method for repeatability measurement using a corneal topography instrument, characterized in that, include: Data acquisition: Multiple independent and repeated measurements were performed on the same test surface using a corneal topography instrument to obtain multiple sets of corneal topography data; Single-point repeatability calculation: Based on the multiple sets of corneal topography data, calculate the single-point standard deviation of each measurement point in the measurement area to characterize the single-point repeatability of each measurement point; Area weighting: Assign an area weight value that represents the spatial representativeness of each measurement point; and Overall repeatability assessment: The overall measurement repeatability index of the corneal topography instrument is obtained by weighting the standard deviation of each measurement point and its corresponding area weight value.
2. The method according to claim 1, characterized in that, In the step "single-point repeatability calculation", the single-point standard deviation s i The result was obtained using the range method.
3. The method according to claim 1, characterized in that, In the step "area weight allocation", the area weight value The calculation formula is: ； Where n is the total number of measurement points, i is the measurement point number, and r i Let be the radius of measurement point i.
4. The method according to claim 1, characterized in that, The step "overall repeatability assessment" further includes: The formula for calculating the area-weighted, repeatable average value M of a single point is: ； Where n is the total number of measurement points, s represents the area weight value. i Let i be the single-point standard deviation of the measurement point i; The formula for calculating the overall measurement standard deviation S after area weighting is: ； The overall measurement standard deviation S, weighted by k times the area, is used as the overall measurement repeatability index, where k is a predefined coefficient; Preferably, the value of k is 2.
5. The method according to claim 1, characterized in that, In the "data acquisition" step, the number of repeated measurements N satisfies 3 ≤ N ≤ 9; the test surface is a spherical test surface or a toroidal test surface that simulates the corneal topography.
6. The method according to claim 5, characterized in that, The measurement points are selected in a polar coordinate system, and the selected measurement points are located within a region with a diameter of 1 mm to 6 mm, with at least 6 different radial distances selected.
7. The method according to claim 6, characterized in that: If the test surface is a spherical test surface, at least 6 distances shall be selected in the radial direction, and the angle interval shall not be greater than 45°. If the test surface is a toroidal test surface, then at least 6 distances should be selected in the radial direction, and the angle positions should be selected in the two principal meridian directions.
8. A repeatability measurement device for corneal topography, characterized in that, include: The data acquisition module is used to perform multiple independent and repeated measurements on the same test surface using a corneal topography instrument to obtain multiple sets of corneal topography data; The single-point repeatability calculation module is used to calculate the single-point standard deviation of each measurement point in the multiple measurement points within the measurement area based on the multiple sets of corneal topography data, so as to characterize the single-point repeatability of each measurement point. An area weight allocation module is used to assign an area weight value representing the spatial representativeness of each measurement point; and The overall repeatability assessment module is used to perform weighted calculations based on the single-point standard deviation of each measurement point and its corresponding area weight value to obtain the overall measurement repeatability index of the corneal topography instrument.
9. An electronic device, characterized in that, include: One or more processors; Memory for storing one or more programs of the processor; When the one or more programs are executed by the one or more processors, the one or more processors perform the method as described in any one of claims 1 to 7.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 7.