Eye Model Ocular Length Measurement Wavefront Aberration Accuracy
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Solution Overview
Problem
Current methods for determining optical aberrations of the eye, such as those using the Tscherning aberrometer, rely on model assumptions for ocular length, leading to inaccuracies in computing defective vision, especially when the actual ocular length differs from the assumed value, resulting in errors in wavefront measurements and subsequent vision correction treatments.
Innovation Solution
The process involves reconstructing wavefront aberrations using an improved eye model that incorporates the actual measured ocular length, allowing for more accurate computation of imaging errors and optimized ablation profiles for laser-surgical refraction corrections and intraocular lens design, including corrections for higher-order aberrations like coma, trefoil, and spherical aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If model assumptions for ocular length are used in wavefront aberration measurement, then the measurement process is simplified and can be performed with standard equipment, but the accuracy of the measurement deteriorates when actual ocular length differs from model assumptions
Solution Approach 1:
The patent changes the parameter of ocular length from a fixed model assumption to a variable that is individually measured for each patient. By incorporating actual biometric measurements of ocular length into the wavefront aberration calculation, the system adapts to individual anatomical variations, thereby improving measurement accuracy without significantly complicating the measurement process
Solution Approach 2:
The patent implements a feedback mechanism where the measured wavefront aberrations are used to iteratively optimize the ocular length parameter. The system adjusts the assumed ocular length based on the measured aberration pattern, creating a closed-loop process that continuously improves measurement accuracy by comparing actual measurements with model predictions
2Productivity
If standard eye models with fixed ocular length are used, then the computational process is simplified and treatment planning is faster, but the precision of vision correction deteriorates for eyes with non-standard ocular length
Solution Approach 1:
The patent performs preliminary biometric measurement of ocular length before wavefront aberration measurement. By obtaining the actual ocular length measurement in advance and incorporating it into the eye model before treatment planning begins, the system eliminates the need for iterative adjustments during treatment planning, thereby maintaining computational efficiency while improving precision
Solution Approach 2:
The patent transforms the static, fixed ocular length parameter in standard eye models into a dynamic, patient-specific value. The system allows the ocular length parameter to be individually determined through biometric measurement and then used throughout the treatment planning process, enabling precise customization without significantly increasing computational complexity
3Measurement precision
If actual ocular length measurements are incorporated into the eye model, then the accuracy of wavefront aberration measurement is improved, but the complexity of the measurement and computational process increases
Solution Approach 1:
The patent uses a multi-functional approach where the same optical system performs both biometric measurement (ocular length) and wavefront aberration measurement. By integrating these functions into a single measurement process, the system improves accuracy without proportionally increasing device complexity, as the additional functionality is achieved through software processing rather than additional hardware
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of wavefront aberration measurements and treatment outcomes by using the actual ocular length, improving the precision of vision correction and intraocular lens design, thereby addressing the limitations of model-based assumptions.
Implementation Method 1
a plurality of component beams are generated from parallel light. The generated component beams exhibit a predetermined two-dimensional arrangement in a plane arranged perpendicular to an optical axis. This arrangement of the component beams is projected through the optical system of the eye
Data Source
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AI summary
A process and an apparatus are proposed for determining optical aberrations of an eye (12) with its optical system (30) including the cornea (32, 173) and the lens (34, 180). The process includes the reconstructing of wavefront aberrations (100) of the eye (12) as a deviation of the wavefront (102), determined by the optical system (30) of the eye (12) with a process of aberrometry, with respect to an ideal planar wavefront (104) generated by an aberration-free eye model. A measured ocular length is employed for the aberration-free eye model.