Wide-Field Swept-Source OCT for Motion-Corrected Anterior Chamber Imaging
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Solution Overview
Problem
Existing ophthalmic OCT systems optimized for retinal imaging are not optimal for anterior chamber measurements due to differences in imaging properties, leading to suboptimal lateral resolution and depth of field, and struggle with motion artifacts when imaging moving objects without contact lenses.
Innovation Solution
A wide-field swept-source OCT system using wavelength-tuned illumination radiation with synchronized illumination pulses and a 2D detector to correct for object movement, allowing high-resolution imaging of the anterior chamber with coherent wide-field illumination and motion compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If retinal OCT systems are adapted for anterior chamber measurements, then the system can be used for anterior chamber imaging, but the lateral resolution and depth of field are not optimal due to differences in imaging properties
Solution Approach 1:
The patent applies local quality by using a confocal detection scheme specifically optimized for anterior chamber imaging while maintaining the swept-source illumination approach. The confocal pinhole is positioned to match the anterior chamber depth range, creating locally optimized detection conditions that improve lateral resolution and depth of field for anterior segment structures without requiring complete system redesign.
2Manufacturing precision
If the numerical aperture is increased to improve lateral resolution, then the lateral resolution improves, but the depth of field decreases significantly
Solution Approach 1:
The patent employs dynamic focusing through variable magnification optics that allow the depth of field to be adjusted during measurement. The system can dynamically change the focal plane and depth of field range to match different anterior chamber structures being imaged, enabling high lateral resolution at specific depths while maintaining the ability to access the full 6mm depth range of the anterior chamber.
3Reliability
If contact lenses are used to stabilize the imaging position, then motion artifacts are reduced, but the imaging procedure becomes more complex and less comfortable for patients
Solution Approach 1:
The patent implements feedback-based motion compensation using the swept-source OCT's inherent ability to track depth changes. The system continuously monitors the optical path length and adjusts the reference arm position to compensate for eye movements, maintaining image stability without requiring contact lenses. This feedback mechanism corrects motion artifacts in real-time during the imaging procedure.
4Productivity
If the illumination intensity is increased to improve imaging speed, then the imaging speed increases, but the risk of eye damage increases
Solution Approach 1:
The patent uses periodic pulsed illumination with the swept-source laser, where the laser wavelength is continuously tuned over time. The illumination is delivered in synchronized pulses that match the camera frame rate, allowing high peak intensities for fast imaging while maintaining low average power to ensure patient safety. The pulsed nature of the illumination combined with the swept-source approach enables high-speed imaging without exceeding safety limits.
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
Achieves high-resolution, motion-corrected imaging of the anterior chamber with improved lateral resolution and depth of field, suitable for imaging moving objects without contact lenses, using a 2D detector and synchronized illumination pulses.
Implementation Method 1
Illuminating the object with the illumination radiation, wherein the illumination radiation is backscattered or reflected in the object as measurement radiation
Implementation Method 2
Illuminating the object with the illumination radiation, wherein the illumination radiation is backscattered or reflected in the object as measurement radiation
Implementation Method 3
imaging the measurement radiation coming from the illuminated object onto a 2D detector
Data Source
Figure 1A
Figure 1B
Figure 2A~2B
AI summary
A wide-field swept-source OCT method for imaging a moving object (14), in particular the anterior chamber (16) of the human eye, is described, the method including the following steps: - providing wavelength-tuned illumination radiation (B) having individual illumination pulses (10.L0, 10.L1) of different centroid wavelengths, - illuminating the object (14) using the illumination radiation (B) and imaging the object (14) on a 2-D detector (22) which has an image recording cycle of exposure intervals (4.1, 4.2, 4.3, 4.4) and read-out intervals (6.1, 6.2, 6.3), - emitting the illumination pulses (10.L0, 10.L1, 10.L2) as a series of illumination pulse pairs (10.L0, 10.L1; 10.L0, 10.L2) of a first illumination pulse (10.L0) and a second illumination pulse (10.L1, 10.L2), with illumination pulses (10.L0) with the same centroid wavelengths being repeated at least once over the illumination pulse pairs (10.L0, 10.L1; 10.L0, 10.L2), - synchronizing the illumination pulses (10.L0, 10.L1, 10.L2) and the detector (22) such that the illumination pulse pairs (10.L0, 10.L1; 10.L0, 10.L2) are grouped around every second (6.1, 6.3) of the read-out intervals (6.1, 6.2, 6.3) of the sequence (2), and - generating image pairs from the detector signals corresponding to the illumination pulse pairs (10.L0, 10.L1; 10.L0, 10.L2), - determining changes between the image data of the illumination pulses (10.L0) with the same centroid wavelength repeated over the illumination pulse pairs (10.L0, 10.L1; 10.L0, 10.L2) and using the changes to correct movements of the object (14) in the image data.