Extended Depth FDOCT Spectral Sampling for Ocular Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current Fourier domain optical coherence tomography (FDOCT) systems face limitations in imaging depth and sensitivity falloff, leading to restricted application in ophthalmology, particularly in imaging deeper ocular structures due to complex conjugate artifacts and sensitivity degradation with depth.
Innovation Solution
The implementation of an extended depth FDOCT system with a detection system configured to sample spectral elements at equal frequency intervals, combined with phase information to remove complex conjugate artifacts and adjust spectral bandwidth, allowing for deeper imaging without compromising axial resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If conventional FDOCT systems use standard spectral sampling, then imaging speed and signal-to-noise ratio are maintained, but imaging depth is limited and sensitivity falloff occurs
Solution Approach 1:
The patent changes the spectral sampling parameters by sampling at equal frequency intervals rather than equal wavelength intervals, and adjusts the spectral bandwidth to be no greater than one-half the frequency interval. This parameter change extends the imaging depth while maintaining sensitivity by optimizing the relationship between sampling rate, bandwidth, and depth range.
Solution Approach 2:
The system dynamically adjusts the spectral bandwidth and sampling characteristics based on the desired imaging depth. By making the detection system configurable with adjustable bandwidth and sampling parameters, the system can adapt to different imaging requirements and maintain optimal sensitivity across extended depth ranges.
2Manufacturing precision
If spectral bandwidth is increased to improve axial resolution, then depth resolution improves, but imaging depth is reduced due to sensitivity falloff
Solution Approach 1:
The patent optimizes the spectral bandwidth parameter to be no greater than one-half the frequency interval, creating an optimal balance between axial resolution and imaging depth. This parameter optimization ensures that sufficient spectral resolution is maintained for good axial resolution while the extended sampling range provides increased imaging depth without sensitivity falloff.
3Device complexity
If standard spectral sampling is used, then system complexity is low, but complex conjugate artifacts appear and mirror image artifacts are generated
Solution Approach 1:
The patent changes the spectral sampling approach to equal frequency intervals with controlled bandwidth, which inherently reduces complex conjugate artifacts. This parameter change modifies the sampling characteristics to minimize artifact generation while maintaining relatively simple system architecture.
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 enables quadruple the available imaging depth, reducing mirror image artifacts and sensitivity falloff, facilitating comprehensive volumetric imaging of the eye, including the anterior segment and retina, with improved signal-to-noise ratio and extended imaging range.
Implementation Method 1
Frequency domain optical coherence tomography (FDOCT) systems are discussed below with respect to FIGS. 1 through 3
Implementation Method 2
The longitudinal ranging capability of OCT is generally based on low-coherence interferometry, in which light from a broadband source is split between illuminating the sample of interest and a reference path
Implementation Method 3
combined with phase information to remove complex conjugate artifacts
Data Source
AI summary
Systems for extended depth frequency domain optical coherence tomography are provided including a detection system configured to sample spectral elements at substantially equal frequency intervals, wherein a spectral width associated with the sampled spectral elements is not greater than one-half of the frequency interval. Related methods are also provided herein.