Optical Coherence Reflectometry Dynamic Focus Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical coherence domain reflectometry (OCDR) techniques face challenges in achieving simultaneous axial and lateral resolution, leading to measurement errors and reduced signal-to-noise ratio, particularly when measuring ocular distances such as anterior chamber depth, lens thickness, and axial length of the eye.
Innovation Solution
The use of a device and method that generates a combined A-scan measurement signal by shifting the focus position or varying the polarization state of the measuring beam during data recording, incorporating multiple individual A-scan signals obtained at different focal positions or polarization states to improve signal quality and reduce measurement errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed focus position is used in OCDR measurement, then the device complexity is reduced, but the signal-to-noise ratio deteriorates and measurement precision is reduced
Solution Approach 1:
The patent implements dynamic focus adjustment by shifting the focal position of the measuring beam along the optical axis during the measurement process. This dynamic focusing allows the system to capture backscattered radiation from multiple depths within the eye, thereby improving the signal-to-noise ratio through signal accumulation from different focal positions without requiring a permanently complex mechanical adjustment mechanism.
Solution Approach 2:
The patent changes the focal position parameter of the measuring beam during measurement. By varying the focal depth parameter dynamically, the system accumulates signals from different depths within the ocular structures, which enhances the overall signal-to-noise ratio and measurement reliability without permanently increasing device complexity.
2Measurement precision
If precise alignment is required for measurement, then measurement precision is improved, but the ease of operation deteriorates
Solution Approach 1:
The patent applies partial focusing action by collecting backscattered radiation from multiple focal positions rather than requiring perfect single-point focus. This approach accumulates sufficient signal from a range of depths, achieving adequate measurement precision without demanding extremely precise manual alignment from the operator, thus improving ease of operation.
Solution Approach 2:
The patent effectively creates multiple copies of the measurement signal from different focal positions and combines them. This signal copying and accumulation approach allows the system to achieve high measurement precision through computational combination of multiple partial measurements, reducing the burden on manual alignment precision.
3Measurement precision
If axial and lateral resolution are simultaneously optimized, then measurement precision is improved, but the device complexity increases
Solution Approach 1:
The patent segments the measurement process into multiple focal position measurements along the axial direction. By dividing the depth measurement into discrete focal segments and combining their signals, the system achieves improved axial resolution without requiring a single complex optical system that simultaneously optimizes all parameters.
Solution Approach 2:
The patent adds the focal position dimension to the measurement process. Instead of relying solely on lateral beam parameters for resolution, the system introduces axial focal positioning as an additional dimension, allowing depth resolution to be improved through focal depth variation without complicating the lateral optical components.
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 signal-to-noise ratio and accurately determines boundary surfaces within the eye, reducing measurement errors and the need for precise alignment, allowing for simultaneous measurement of ocular distances with improved resolution and accuracy.
Implementation Method 1
a measurement signal indicative of structures of the eye is generated interferometrically by time domain, spectral domain or Fourier domain coherence reflectometry
Implementation Method 2
focusing at least one measuring beam along an optical axis into the eye
Implementation Method 3
an adjusting device for lateral and/or axial displacement of the focus in the eye
Data Source
Figure 1~3
Figure 4a~7
Figure 4b~13
AI summary
A device for performing measurements on an eye (4), in particular for measuring the depth of the anterior chamber, the lens thickness, the corneal thickness or the axial length, wherein the device comprises an interferometer (10), focuses at least one measurement beam (7, 8) into the eye (4) along an optical axis (OA), records backscattered radiation and interferometrically generates a measurement signal displaying structures of the eye by time-domain, spectral-domain or Fourier-domain coherence reflectometry, has an adjustment apparatus for laterally and/or axially displacing (P, T) the focus in the eye (4) or for varying a polarization state of the measurement beam (7, 8) and has a control apparatus which actuates the interferometer, wherein the control apparatus generates a plurality of A-scan individual signals from the backscattered radiation, combines these to an A-scan measurement signal and is designed such that it actuates the adjustment apparatus for displacing the position of the focus or for varying the polarization while recording the backscattered radiation from which the control apparatus generates the A-scan individual signals is being recorded and backscattered radiation contributes to the A-scan measurement signal in a plurality of different positions of the focus or in a plurality of different polarization states of the measurement radiation (7, 8).