Spinning Disk Retinal Imaging Rejects Afocal Light
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Solution Overview
Problem
Current imaging modalities for the human retina face limitations in resolving small objects due to afocal haze, which reduces sensitivity and image quality, and are either costly and complex, like confocal laser scanning ophthalmoscopes, or plagued by artifacts and reflections, like flood illumination systems.
Innovation Solution
A system that combines elements of confocal microscopy and coded optical systems using a spinning disk with a reflective surface and adjustable pinholes or slits to reject afocal light, allowing for greater control over image quality and portability, while maintaining focal specificity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If flood illumination is used to image the retina, then the system cost is reduced and the system is simplified, but afocal haze and artifacts increase, reducing image quality and sensitivity
Solution Approach 1:
The patent segments the illumination into multiple focal planes using a light field lens array, with a movable mask selectively blocking light from out-of-focus planes. This allows the system to achieve confocal-like rejection of afocal light without the complexity of scanning mechanisms, resolving the contradiction between system simplicity and image quality.
Solution Approach 2:
The patent introduces a light field lens array and movable mask as intermediary elements between the illumination source and the retina. These components enable selective blocking of afocal light paths while maintaining focus on the retinal plane, improving image quality without requiring complex confocal scanning systems.
2Measurement precision
If confocal laser scanning ophthalmoscopy is used to reject afocal light, then image quality and resolution are improved, but system cost and component complexity increase significantly
Solution Approach 1:
The patent replaces the complex mechanical scanning system of traditional confocal ophthalmoscopes with a stationary light field lens array and a simple movable mask. This substitution maintains the ability to reject afocal light and achieve high image quality while dramatically reducing mechanical complexity and system cost.
Solution Approach 2:
The patent employs periodic movement of the mask to selectively block light from different focal planes during the imaging process. This periodic action enables confocal-like rejection of afocal light without requiring continuous scanning, simplifying the system while maintaining image quality.
3Ease of manufacture
If flood illumination delivers light in both focal and out of focus planes, then the system is simpler and less costly, but numerous artifacts and reflections are produced that block image regions
Solution Approach 1:
The patent extracts and selectively blocks the harmful out-of-focus light components using a movable mask positioned in the light field. This removes the source of artifacts and reflections while preserving the simple flood illumination architecture, resolving the contradiction between system simplicity and artifact reduction.
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 enhances image resolution and sensitivity by effectively rejecting afocal light, improving image quality without the high cost and complexity of confocal systems, and allowing for interchangeable disks to optimize image focus and collection efficiency.
Implementation Method 1
This type of confocal makes use of the confocal pinhole effect, and may include a pinhole of changing diameter, to allow the operator of the system control over the confocality of the image and corresponding rejection of afocal light.
Implementation Method 2
A system that combines elements of confocal microscopy and coded optical systems using a spinning disk with a reflective surface and adjustable pinholes or slits to reject afocal light
Data Source
AI summary
A system and method for rejecting afocal light collected from an in vivo human retina is disclosed. The system may include a detector, a server system being in communication with the detector and a memory system with a rejection of collected afocal light and a disk having an optointerruptor and a motor, which is speed controlled via a non-transitory storage media. The method includes utilizing a series of optical shapes or codes, similar to other structured illumination systems, illuminating the series of optical shapes or codes several times, collecting and processing the series of optical shapes or codes yielding measurements of optical noise and optical signal and subtracting the noise and signal from the final image.