OCT Reference Path Switching for Extended Depth Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Intracocular surgeries face challenges in visualizing microstructural changes due to the translucent nature of eye tissues, limiting the ability to accurately perform procedures like cataracts, diabetic retinopathy, and retinal detachment surgeries, where conventional microscopes fail to provide sufficient depth of field and signal-to-noise ratio for real-time image registration and blending.
Innovation Solution
An optical coherence tomography (OCT) system with a broadband source, beamsplitter, optical switch, and processor that switches reference paths to acquire and combine wavelength-dependent interferograms, enabling extended depth imaging through spatial offset and blending of A-scans, improving signal-to-noise ratio and depth-dependent image registration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional microscopes are used for ophthalmic surgery, then the system is simple and easy to operate, but the depth of field and signal-to-noise ratio are insufficient for visualizing microstructural changes
Solution Approach 1:
The reference arm is divided into multiple segments (first reference path and second reference path) with different optical path lengths, allowing the system to acquire interferograms at multiple depth ranges and combine them to achieve extended depth of field
Solution Approach 2:
The system transitions from single-depth-plane imaging to multi-depth-plane imaging by introducing an additional dimension of optical path length variation through the optical switch, enabling extended depth range visualization
2Measurement precision
If conventional microscopes are used for ophthalmic surgery, then the system is simple, but the signal-to-noise ratio is insufficient for real-time image registration and blending
Solution Approach 1:
The system merges multiple interferograms acquired at different reference path positions through computational blending algorithms, combining the signals to achieve improved signal-to-noise ratio while maintaining real-time imaging capability
Solution Approach 2:
The optical switch acts as an intermediary device that rapidly toggles between different reference path configurations, enabling the acquisition of multiple interferograms that are subsequently processed to enhance signal quality
3Length of stationary object
If reference path switching is implemented to extend depth range, then depth of field is improved, but device complexity increases due to optical switch and multiple reference paths
Solution Approach 1:
The reference arm is made dynamic through the optical switch that rapidly toggles between different path configurations during image acquisition, allowing the system to adaptively sample multiple depth ranges and combine them computationally to achieve extended depth of field
4Measurement precision
If multiple interferograms are acquired and combined, then signal-to-noise ratio is improved, but processing time increases for real-time imaging
Solution Approach 1:
The system performs preliminary acquisition of multiple interferograms in rapid succession using the optical switch before computational blending, preparing the data set in advance to enable real-time processing and display without excessive delay
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
Enhances surgical precision by providing high-resolution, real-time imaging with improved depth of field and signal-to-noise ratio, allowing for better visualization of surgical instruments and tissue changes during ocular surgeries, thus reducing surgical trauma and improving anatomical outcomes.
Implementation Method 1
A beam combiner mixes source radiation reflected from a subject in the sample path with source radiation returned from the first reference reflection during a first time interval and the second reference reflection during a second time interval
Data Source
AI summary
An optical coherence tomography (OCT) system including a source of broadband optical radiation and a beamsplitter coupled to the source is provided. The beamsplitter divides the source radiation into a reference path and a sample path. The reference path includes an optical switch to switch the reference path between a first path having a first reference reflection at a first reference optical path length and a second path having a second reference reflection at a second reference optical path length. The system further includes a beam combiner that mixes source radiation reflected from a subject in the sample path with source radiation returned from the first reference reflection and the second reference reflection. A detection system detects a first wavelength dependent interferogram during the first time interval and a second wavelength dependent interferogram during the second time interval. A processor preconditions the first and second wavelength dependent interferograms.