Rodent Eye Imaging Using Ring Light and Contact Lens
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Solution Overview
Problem
Current imaging systems designed for human eyes are inadequate for imaging the back of rodent eyes due to size and structural differences, resulting in poor quality and limited resolution images, especially for fluorescent angiography and auto-fluorescence.
Innovation Solution
A method and apparatus that inject a ring of light through the entrance pupil of the rodent eye, using a contact lens to stabilize and align the eye, and an optical system to collect and focus light reflected from the back interior portion, allowing for wide-field, high-resolution imaging with options for fluorescent imaging, suitable for rodents and potentially larger animals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If standard human eye imaging systems are used for rodent eyes, then the imaging system is readily available, but the image resolution and quality are poor due to size differences
Solution Approach 1:
The patent modifies the imaging system parameters specifically for rodent eyes by adjusting the working distance to 2-10mm from the eye surface, changing the field of view to 60-90 degrees, and adjusting the focal length to accommodate the 3-6mm rodent eye diameter compared to human eyes. These parameter changes enable high-resolution imaging of rodent eyes while maintaining system availability.
2Area of stationary object
If conventional cameras are used to image rodent eyes, then images can be produced, but the field of view is limited and resolution is poor
Solution Approach 1:
The patent employs a curved or dome-shaped imaging interface that matches the curvature of the rodent eye surface, allowing wide-angle illumination and capture across the entire retinal surface. This curved geometry enables a 60-90 degree field of view while maintaining focus and resolution across the wide field, overcoming the limitations of conventional flat camera designs.
3Measurement precision
If imaging is performed without proper alignment, then the setup is simple, but only a small portion of the image is in focus due to eye curvature
Solution Approach 1:
The patent introduces a contact lens or immersion interface as an intermediary between the imaging system and the rodent eye. This intermediary element provides optical coupling that compensates for the eye's curvature, ensuring that the entire retinal surface remains in focus throughout the 60-90 degree field of view. The contact lens acts as a mediator that simplifies alignment while maintaining image quality.
4Reliability
If the minimum pupil diameter requirement of 4mm is applied, then non-mydriatic cameras can be used, but rodent pupils are too small (2-4mm maximum dilation)
Solution Approach 1:
The patent adjusts the imaging system's optical parameters to accommodate the smaller rodent pupil diameter of 2-4mm maximum dilation. This includes increasing the numerical aperture of the imaging lens, adjusting the working distance to 2-10mm, and modifying the illumination intensity to compensate for the smaller aperture. These parameter changes enable reliable imaging of rodent eyes regardless of pupil size, making the system adaptable to both mydriatic and non-mydriatic conditions.
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
Enables high-resolution, wide-field imaging of the back of rodent eyes with resolutions below 5 microns and the capability for fluorescent angiography and auto-fluorescence, improving image quality and versatility for various animal species.
Implementation Method 1
collecting light reflected off of the back interior portion of the eye
Implementation Method 2
focusing the collected light reflected off of the back interior portion of the eye and thereby forming an image
Data Source
AI summary
Imaging an eye of an animal can include injecting a ring of light through an outer portion of an entrance pupil of the eye of the animal onto a back interior portion of the eye. Light reflected off of the back interior portion of the eye and through an exit pupil effectively located at the entrance pupil within the ring of light can be collected. A diameter of the exit pupil at the entrance pupil can be less than an inner diameter of the ring of light, and a difference between an outer diameter of the ring and the inner diameter of the ring can be at least twenty percent of a diameter of the eye. The collected light reflected off of the back interior portion of the eye can be focused to thereby form an image of the back interior portion of the eye.