Variable Scan Depth SD-OCT System with Multi-Grating Spectrometer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current Optical Coherence Tomography (OCT) systems, particularly spectral domain OCT (SD-OCT), face limitations in increasing scan rate and adjusting scan depth without compromising spatial resolution, and existing methods lack flexibility in configuring optical fiber sources to support variable scan rates and depths.
Innovation Solution
The system employs multiple gratings with different grating periods that can be positioned in and out of the optical path to enable variable scan depth SD-OCT, along with a fiber optic switch and beam dividers to selectively direct light into sample and reference arms, allowing for single, dual, or quadruple scanning modes, and a multi-fiber ferrule to increase scan rate by sharing the same optical path with fixed delay between beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the scan rate of an OCT system is increased to support wider scans, then the field-of-view coverage is improved, but the spatial resolution may be compromised
Solution Approach 1:
The patent divides the scanning task into multiple parallel scan beams (single, dual, or quadruple scanning modes) that simultaneously image different sectors of the sample. This segmentation allows the system to cover a wider field-of-view through multiple beams while each beam maintains sufficient spatial resolution, resolving the contradiction between coverage area and resolution.
2Measurement precision
If an SD-OCT system is designed for a specific scan depth, then the imaging quality at that depth is optimized, but the system lacks flexibility to adjust scan depth for different applications
Solution Approach 1:
The patent implements a variable scan depth mechanism in SD-OCT systems by allowing dynamic adjustment of the optical path length in the reference arm. This enables the system to adapt scan depth to different imaging requirements while maintaining optimal imaging quality, transforming a static system into a dynamically adjustable one that resolves the contradiction between optimized performance and versatility.
3Productivity
If multiple scan beams are used to quadruple the OCT line rate, then the scan rate is improved, but the system configuration becomes complex and limited to fixed beam arrangements
Solution Approach 1:
The patent designs an optical system with a unified optical path that can operate in multiple scanning modes (single, dual, or quadruple scanning) by reconfiguring the same optical components. This multi-functional design allows the system to achieve high scan rates when needed while maintaining simplicity for standard operations, reducing overall system complexity while preserving high productivity capability.
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 configuration allows for variable scan depth and rate, enabling wider field-of-view imaging without compromising spatial resolution, and supports multiple scan depth options within the same SD-OCT system, enhancing its applicability in ophthalmology and other fields.
Implementation Method 1
a spectrometer for measuring light returning from the sample and reference arms as a function of wavelength
Data Source
AI summary
The system, method and device includes an optical coherence tomography (OCT) system switchable between single scan mode or multi-scan mode. This is achieved by use of multiple beam splitters to produce multiple OCT beams, but the system still uses a single light source, a single sample arm, and single reference arm to achieve a compact, more cost effective, system. Additionally presented is a spectral domain OCT system with a spectrometer having multiple grating, each providing a different depth and/or resolution imaging capability.