Multi-Angle Eye Imaging for Patient-Specific Refractive Index Models
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Solution Overview
Problem
Current ophthalmic imaging techniques lack non-invasive methods to determine patient-specific refractive indices of the optical components in the eye, relying instead on averaged or invasive measurements, which hinders accurate geometric modeling and surgical planning.
Innovation Solution
A non-invasive method using ophthalmic imaging systems like OCT and aberrometry to take measurements at multiple incident beam directions, generating 3D reconstructions with varying refractive indices, and comparing these reconstructions to identify a congruent set of true refractive indices through ray tracing and error analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If averaged patient-independent refractive indices are used, then the imaging process is simplified and faster, but the accuracy of geometric model reconstruction deteriorates
Solution Approach 1:
The system dynamically adjusts refractive index parameters from fixed averaged values to patient-specific values by analyzing multiple images at different incident beam angles. The refractive indices are treated as variable parameters that are optimized to match the actual optical characteristics of each patient's eye, enabling both speed and accuracy through automated parameter adaptation.
Solution Approach 2:
The system uses feedback from multiple images taken at different angles to iteratively refine the refractive index values. By comparing images and analyzing discrepancies, the system automatically adjusts the refractive index parameters until the models converge, ensuring accurate patient-specific reconstruction without manual intervention.
2Measurement precision
If invasive measurement techniques are used, then refractive indices can be directly measured, but patient safety and comfort deteriorate
Solution Approach 1:
Instead of directly measuring the refractive indices through invasive procedures, the system creates optical copies or models of the eye's optical components by analyzing reflected and transmitted light patterns from external images. These virtual models allow indirect determination of refractive indices without physical intrusion into the eye.
Solution Approach 2:
The system introduces intermediary measurements through non-invasive imaging at multiple angles as a mediator between the external observer and the internal optical properties of the eye. By analyzing light interactions at the eye's surfaces and using ray tracing models, the system infers internal refractive indices without direct contact or invasion.
3Measurement precision
If multiple images at different incident beam angles are analyzed, then patient-specific refractive indices can be determined, but the device complexity and processing time increase
Solution Approach 1:
The imaging system is designed to perform multiple functions using the same hardware: capturing images at various incident beam angles, analyzing optical patterns, and determining patient-specific refractive indices. By making the imaging system multi-functional, the patent avoids requiring separate specialized equipment for each measurement type, thereby managing complexity while achieving comprehensive analysis.
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
Enables accurate patient-specific modeling of the eye, facilitating better surgical planning and diagnosis by determining the actual conditions within the eye, improving cataract surgery outcomes and retinal disease assessment.
Implementation Method 1
The human eye has a gradient of refractive index, which typically increases from the edge to the center of the eye. The cornea, aqueous humor, lens, and vitreous humor each has a different index of refraction.
Implementation Method 2
Ophthalmic imaging techniques, such as optical coherence tomography (OCT), confocal scanning laser ophthalmoscopy, and scanning laser polarimetry
Data Source
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AI summary
The present disclosure provides a non-invasive technique to determine a true set of refractive indices of a patient's eye in order to generate an accurate model of the patient's eye. Certain aspects provide a system for generating a three-dimensional reconstruction model of a patient's eye. The system includes an imaging device configured to generate first and second measurements of a patient's eye at first and second angles relative to a line of sight of the patient's eye. The system includes an image processor configured to generate a first and second plurality of models of the patient's eye based on applying a plurality of sets of refractive indices to the first and second measurements; identify a first model from the first plurality of models that is congruent with a second model from the second plurality of models; and determine a set of refractive indices associated with the first and second models.