Eye Length Measurement Using Off-Axis OCT Beam Patterns
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Solution Overview
Problem
Existing methods for measuring eye length, such as ultrasound and time-domain OCT, are prone to artifacts and false signals, requiring time-consuming manual identification and compensation.
Innovation Solution
A decentralized scanning approach using multiple light beams, including a central beam and peripheral beams offset from the optical axis, to create a point pattern on the cornea, allowing for artifact suppression and accurate detection of the retinal pigment epithelium by analyzing intensity differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If time-domain OCT is used to measure eye length, then measurement capability is provided, but the measurement is artifact-laden and slow
Solution Approach 1:
The patent replaces time-domain OCT measurement methodology with Fourier domain OCT, substituting a mechanical/time-based measurement approach with a frequency-domain approach that enables parallel processing of multiple depth points simultaneously, thereby dramatically reducing measurement time while maintaining accuracy
Solution Approach 2:
The patent changes the fundamental measurement parameter from time-domain to frequency-domain (Fourier domain) OCT, transforming the measurement approach to enable artifact-free measurements through spectral analysis and phase information extraction, which naturally suppresses artifacts without requiring time-consuming manual identification
2Measurement precision
If traditional OCT methods are used, then eye length can be measured, but false signals from layers must be identified manually
Solution Approach 1:
The patent replaces manual signal identification with automated Fourier domain processing algorithms that mathematically separate true retinal signals from artifacts through spectral analysis, eliminating the need for manual intervention while maintaining high measurement accuracy
Solution Approach 2:
The patent introduces Fourier transformation as an intermediary mathematical process that acts as a mediator between the raw OCT signal and the final measurement, automatically filtering out artifacts and false signals through frequency domain analysis before presenting clean measurement data
3Measurement precision
If light beams are directed along the optical axis, then central measurement is achieved, but specular reflection at the cornea creates artifacts
Solution Approach 1:
The patent introduces asymmetric scanning patterns that deliberately offset light beams from the optical axis, creating non-central measurement paths that avoid the specular reflection zone at the corneal vertex while still enabling accurate eye length measurement through computational reconstruction
Solution Approach 2:
The patent transitions from one-dimensional central optical axis measurement to two-dimensional off-axis scanning patterns, utilizing lateral spatial dimensions to bypass corneal reflection artifacts while maintaining measurement capability through mathematical processing of the expanded data space
4Reliability
If multiple peripheral light beams are used to compensate artifacts, then artifact suppression is achieved, but device complexity increases
Solution Approach 1:
The patent makes the Fourier domain OCT system multi-functional by enabling it to simultaneously perform multiple depth points measurement, artifact suppression, and phase information extraction through a single unified frequency-domain processing framework, eliminating the need for separate dedicated systems for each function
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 rapid, artifact-free determination of eye length with improved sensitivity and accuracy using Fourier domain OCT devices, eliminating false signals and ambiguities.
Implementation Method 1
a plurality of light beams emitted by the light source are substantially refracted by the lens and deflected onto approximately the same point or area of the retina
Implementation Method 2
light beams reflected by the eye in response to the emitted light beams are detected and converted into signals
Data Source
AI summary
In view of the problem of specifying an arrangement and a method by means of which an eye can be measured preferably without artifacts and quickly, an arrangement for measuring an eye (1), comprising a light source (2) which is suitable for emitting light rays (3, 4) to the cornea (5) of an eye (1) and a control unit (6) which drives the light source (2) to emit the light rays (3, 4) and is suitable for converting reflected light rays (3a, 4a, 4b) entering the arrangement into signals (7, 8), is characterized in that the light source (2) when driven by the control unit (6) emits a central light ray (3) and emits a plurality of peripheral light rays (4) which are radially offset with respect to the central light ray (3) or in that the light source (2) when driven by the control unit (6) emits a plurality of peripheral light rays (4) radially offset with respect to one another. Moreover, a method is specified.