Choroidal Imaging Off-Axis Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Imaging of the choroidal vessels in the eye is challenging due to shielding by retinal pigment and direct reflections, which obscure clear visualization.
Innovation Solution
A broad-field multi-channel imaging device uses off-axis illumination and image processing techniques to reduce direct reflections and enhance visibility of choroidal vessels, capturing a wider field of view by employing multiple imaging channels with angled illumination and image sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional on-axis illumination is used, then the imaging setup is simple, but the retinal pigment and RPE shield and mask the choroidal vessels, preventing clear imaging
Solution Approach 1:
The patent transitions from on-axis illumination to off-axis illumination, changing the spatial dimension of light delivery. By illuminating the choroid from an angle rather than directly from above, the system bypasses the masking effect of the retinal pigment and RPE, allowing light to reach and reflect from the choroidal vessels more effectively.
Solution Approach 2:
The patent employs asymmetric illumination geometry where the illumination path is separated from the imaging path by an offset angle. This asymmetric arrangement creates different optical paths for illumination and detection, enabling the illumination light to reach the choroid while the reflected light is captured by the image sensor without being blocked by the overlying retinal structures.
2Device complexity
If direct illumination is used, then the illumination path is simple, but reflection off the retina and RPE prevents obtaining a clear image of choroidal vessels
Solution Approach 1:
The patent extracts the harmful reflected light from the imaging path by using off-axis illumination. The illumination is delivered at an angle such that the direct reflection off the retinal surface and RPE does not enter the image sensor, effectively removing the interference source from the detection path.
Solution Approach 2:
The offset illumination angle acts as an intermediary mechanism that mediates between the light source and the image sensor. By introducing this angular offset, the system allows illumination to reach the choroid while preventing the harmful reflected light from directly entering the sensor, thus mediating the interaction between illumination and detection.
3Device complexity
If single imaging channel is used, then the device is simpler, but the field of view is limited and cannot capture expansive choroidal structures
Solution Approach 1:
The patent divides the imaging system into multiple imaging channels, each capturing a specific portion of the choroidal field of view. By segmenting the overall imaging task across multiple channels with different angular offsets, the system achieves comprehensive coverage of the expansive choroidal structures that would be impossible with a single channel.
Solution Approach 2:
Each imaging channel is designed to perform the same basic imaging function but with different angular orientations. This multi-functional arrangement allows the system to capture various regions of the choroid from different angles, providing universal coverage of the entire choroidal vasculature while maintaining the simplicity of individual channel design.
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 provides a robust and expansive view of the choroid, allowing greater visibility of choroidal vasculature, particularly in the macular region and periphery, and enables the capture of indices for analysis, such as vascular caliber and tortuosity, which can be used for diagnostic purposes.
Implementation Method 1
illuminating a region of a choroid of an eye of a patient with off-axis illumination from a first imaging channel, the off-axis illumination from the first imaging channel being off-set within the first imaging channel from the image sensor
Implementation Method 2
identifying vascular caliber and tortuosity, which can be used for diagnostic purposes
Data Source
AI summary
A method may include illuminating a region of a choroid of an eye of a patient with off-axis illumination from a first imaging channel, the first imaging channel being off-axis with respect to an axis of a focus of the eye. The method may also include capturing an image of the choroid, where the off-axis illumination from the first imaging channel is off-set within the first imaging channel from the image sensor. A second off-axis illumination from a second imaging channel that is off-axis from both the first imaging channel and the off-axis illumination may illuminate the same or a different region of the choroid. The captured image of the choroid may be provided to a machine learning system. Indices associated with the image to may be identified based on an output of the machine learning system.