Eye-tracking fundus imaging with segmented near-infrared light array
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fundus imaging systems require patients to fixate on a target, which can be challenging for individuals with eye movement issues or young children, leading to misalignment and degraded image quality due to vignetting of illumination light.
Innovation Solution
A fundus imaging system with an array of light sources and an eye-tracking mechanism that maintains illumination of the fundus regardless of eye alignment or movement, using near-infrared light and optical combiners to ensure consistent imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single illumination source is used for fundus imaging, then the device structure is simple, but the illumination is blocked when the eye is misaligned causing vignetting and degraded image quality
Solution Approach 1:
The single illumination source is segmented into multiple light sources arranged in an array. Each light source can be independently controlled to illuminate the fundus from different angles. This segmentation allows the system to maintain reliable illumination even when the eye is misaligned, as multiple light sources can compensate for blocking by any single source.
Solution Approach 2:
The system dynamically selects and activates specific light sources from the array based on real-time eye tracking data. When eye misalignment is detected, the system dynamically adjusts which light sources are active to maintain proper illumination geometry, transforming the static single-source system into a dynamic multi-source system that adapts to eye position.
2Reliability
If patients are required to fixate on a target for proper alignment, then accurate illumination can be achieved, but the ease of operation deteriorates for patients with eye movement issues or young children
Solution Approach 1:
The system performs eye tracking and automatic light source selection without requiring patient cooperation or fixation on targets. The eye-tracking mechanism automatically monitors eye position and the control system autonomously adjusts which light sources are active, making the system self-adjusting and eliminating the need for patient participation in the alignment process.
Solution Approach 2:
The system implements continuous feedback through eye tracking to monitor eye position and automatically adjusts the active light sources accordingly. This closed-loop feedback mechanism ensures proper illumination alignment is maintained without requiring the patient to consciously control their eye fixation, as the system continuously adapts to the actual eye position.
3Device complexity
If the illumination source is fixed relative to the imaging axis, then the device structure is simple, but the illumination is vigneted when the eye moves from the central position
Solution Approach 1:
The fixed illumination source is replaced with a segmented array of multiple light sources positioned at different locations. This segmentation allows the system to tolerate eye movements by having multiple potential illumination paths available, with the appropriate sources activated based on eye position.
Solution Approach 2:
The system adds spatial distribution across multiple dimensions by arranging light sources in an array rather than using a single point source. This multi-dimensional arrangement provides redundancy and adaptability to eye movements in different directions, allowing the system to maintain illumination quality even when the eye moves from the central position.
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
The system achieves invariant illumination and high-quality fundus imaging even when the eye is not directly aligned with the illumination source, improving image quality and usability for diverse patient populations.
Implementation Method 1
wherein one or more of the light sources in the array are selectively enabled to emit illumination light based on the determined movements of the eye
Implementation Method 2
A fundus imaging system with an array of light sources and an eye-tracking mechanism that maintains illumination of the fundus regardless of eye alignment or movement, using near-infrared light and optical combiners to ensure consistent imaging
Data Source
AI summary
A fundus illumination system includes an array of light sources, a first optical combiner, and a second optical combiner. The array of light sources are configured to be selectively enabled to emit non-visible light to illuminate a fundus of an eye. The first optical combiner is configured to receive reflected non-visible light that is reflected by the eye, direct a first component of the reflected non-visible light to a first camera to generate an image of the eye, and pass a second component of the reflected non-visible light. The second optical combiner is configured to receive a fundus imaging light responsive to the second component of the reflected non-visible light, and to direct the fundus imaging light to a second camera to generate an image of the fundus.