Diffractive Fundus Lens for Compact Retinal Topography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing retinal topography systems are bulky, complex, and expensive, making them costly and difficult to use for determining retinal topography, which is crucial for diagnosing conditions like glaucoma where changes in optic disc topography precede visual field loss.
Innovation Solution
A retinal topography system utilizing a diffractive fundus lens with a diffraction optical element (DOE) and two aspheric lenses that projects a predetermined pattern onto the retina, allowing for the gathering and processing of scattered light to determine retinal topography, reducing size, cost, and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a bulky off-axis illumination system is used to illuminate the off-axis portion of the fundus with a pattern of linear stripes, then retinal topography information can be derived, but the system becomes bulky, complex, expensive, and adds to cost, weight, volume, and complexity
Solution Approach 1:
The patent combines the illumination function and imaging function into a single integrated fundus lens assembly. The DOE is integrated within the lens structure itself, eliminating the need for separate off-axis illumination systems and brackets. This merging of functions directly reduces system complexity, volume, and weight while maintaining the ability to derive retinal topography information.
Solution Approach 2:
The fundus lens assembly serves multiple functions simultaneously: it acts as an illumination device projecting the pattern onto the retinal surface, a focusing element for the camera, and an optical adapter for the existing fundus camera. This multi-functionality eliminates the need for separate dedicated components, thereby reducing overall system complexity and cost.
2Measurement precision
If a bulky off-axis illumination system is attached to the fundus camera by means of a bracket, then retinal topography can be analyzed, but the system adds to cost, weight, volume, and complexity
Solution Approach 1:
The illumination system is merged into the fundus lens assembly itself rather than being a separate attached component. The DOE is integrated within the lens structure, eliminating the need for external brackets and separate illumination devices, thereby significantly reducing the overall weight of the system while maintaining topography analysis capability.
3Device complexity
If a diffractive optical element is placed between the aspheric lenses to project a predetermined pattern, then retinal topography can be determined with a compact system, but the DOE may cause aberrations to the scattered beam
Solution Approach 1:
The patent employs aspheric lenses with specific curvature parameters to compensate for aberrations introduced by the DOE. By carefully selecting and designing the aspheric coefficients and lens parameters, the system maintains image sharpness and focuses light to a sharp planar intermediate image despite the presence of the diffractive element, thus resolving the aberration issue while maintaining compactness.
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 simplifies retinal topography analysis, making it more accessible and cost-effective, improving diagnostic capabilities for eye conditions by providing a compact and efficient method to measure retinal changes.
Implementation Method 1
a diffractive optical element (DOE)... When illuminated by an off access light source, the DOE allows a predetermined pattern to be imaged on the fundus (retina)
Implementation Method 2
The first and second aspheric lenses are operable to gather light scattered by the fundus and provide the gathered light to a fundus camera
Data Source
AI summary
Embodiments of the present invention provide a fundus lens. This fundus lens includes a first aspheric lens and a second aspheric lens and a diffractive optical element. This diffractive optical element is placed between the first and second aspheric lens and illuminated by an off access light source. The diffractive optical element contains a predetermined pattern which may be directed and imaged on a fundus. The first and second aspheric lenses are operable to gather light scattered by the fundus and provide the gathered light to a fundus camera. This fundus camera may then be operable to process the gathered light and determine the topography of the fundus.