Dynamic Illuminator Expands Retinal Camera Eyebox
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Solution Overview
Problem
Conventional retinal cameras have small eyeboxes, making precise alignment challenging and leading to optical aberrations and image artifacts, which are exacerbated by increased brightness rather than improved.
Innovation Solution
A dynamic illuminator system that adjusts its illumination pattern based on alignment with the eye, switching between circular and non-circular patterns to expand the eyebox without complex mechanical components, reducing image artifacts by strategically directing illumination and image paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If illumination brightness is increased to improve image fidelity, then image quality improves, but optical artifacts such as corneal reflections, iris reflections, and lens flare become more pronounced
Solution Approach 1:
The illumination system is segmented into multiple independent LED sources arranged in a circular array, allowing selective activation of specific segments based on eye alignment position. This enables the system to provide bright illumination to the retina while avoiding illumination paths that would create corneal reflections, iris reflections, or lens flare artifacts.
Solution Approach 2:
Different regions of the illumination array are activated based on the local alignment conditions. When the eye is properly aligned, only specific angular segments of LEDs are activated to illuminate the retina without creating artifacts. The illumination quality is optimized locally for each angular position rather than using uniform illumination from all sources.
2Object-affected harmful factors
If a small eyebox is used to block optical artifacts, then image fidelity is maintained, but camera alignment becomes difficult and patient interactions become strained
Solution Approach 1:
The illumination system dynamically adjusts which LED segments are activated based on real-time detection of eye alignment. The system transitions from a static, fixed eyebox approach to a dynamic system that adapts the effective illumination aperture based on the patient's eye position, maintaining artifact blocking while guiding alignment through feedback.
Solution Approach 2:
The system uses feedback from eye alignment detection to control which illumination segments are active. This feedback mechanism allows the system to maintain a functional eyebox for artifact blocking while providing visual or system feedback to guide the patient into proper alignment, reducing the strain of manual alignment procedures.
3Measurement precision
If motorized stages are used to automatically adjust retinal camera alignment, then alignment precision improves, but device complexity and cost increase substantially
Solution Approach 1:
The system replaces complex motorized mechanical adjustment stages with an optical/electronic solution using an array of independently controllable LED illumination sources. Instead of mechanically moving the camera or eyepiece to achieve alignment, the system uses selective illumination from different angular positions to achieve the same alignment effect, eliminating complex mechanical components while maintaining alignment precision.
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 dynamic illuminator system effectively expands the eyebox by 2× or more, easing alignment and reducing image artifacts, thereby improving image fidelity and patient interaction during retinal imaging.
Implementation Method 1
illumination light from the dynamic illuminator to illuminate a retina of the eye. The retinal image travels along an image path to an image sensor
Implementation Method 2
A center baffle blocks stray illumination light to reduce image artifacts while allowing the retinal image to pass through to the image sensor
Data Source
AI summary
A retinal imaging system includes an image sensor for acquiring a retinal image and an illuminator for illuminating a retina to acquire the retinal image. The illuminator surrounds an aperture through which an image path for the retinal image passes before reaching the image sensor. Illumination sources surround the aperture.