Cornea Imaging Apparatus Aligning Optical Axis to Endothelium Normal Vector
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Solution Overview
Problem
Conventional cornea imaging apparatuses face challenges in obtaining clear images of the corneal endothelium, especially in the peripheral area, due to anatomical differences in curvature between the corneal endothelium and epithelium, leading to inaccurate alignment and increased burden on both the tester and the test subject.
Innovation Solution
A cornea imaging apparatus with a collimation axis holding mechanism, an illumination optical system, and actuating means to adjust the inclination angle and position of the imaging mechanism to align the imaging center axis with the normal vector direction of the corneal endothelium, ensuring accurate imaging across a wide range despite individual variations in curvature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If XY alignment is performed using specularly reflected light from the corneal epithelium in the same direction for both center and peripheral portions, then the alignment process is simplified, but the imaging accuracy of the corneal endothelium in the peripheral portion deteriorates due to curvature differences
Solution Approach 1:
The patent applies local quality by differentiating the alignment approach for different regions of the cornea. For the central portion, XY alignment uses specularly reflected light from the corneal epithelium. For the peripheral portion, the system performs Z-direction alignment specifically for the corneal endothelium based on curvature information, allowing each region to be aligned according to its specific optical characteristics rather than using a uniform alignment method.
Solution Approach 2:
The patent implements dynamics by making the alignment process adaptive rather than static. The system dynamically adjusts the alignment strategy based on the imaging position (central vs. peripheral) and curvature information. The Z-direction actuating means enables real-time adjustment of the imaging optical system's position to maintain optimal alignment with the corneal endothelium across different regions.
2Measurement precision
If manual XY alignment adjustment is performed repeatedly to obtain clear images of the corneal endothelium, then imaging accuracy can be improved, but the time required and burden on the tester increase significantly
Solution Approach 1:
The patent applies preliminary action by performing Z-direction alignment based on curvature information before actual endothelium imaging. The system calculates the required Z-direction offset from curvature data and pre-adjusts the imaging optical system's position, eliminating the need for repeated manual trial-and-error adjustments during the imaging process.
Solution Approach 2:
The system uses curvature information as feedback to automatically determine the appropriate Z-direction alignment position. By measuring or obtaining curvature data and using it to adjust the imaging system's position, the patent creates a closed-loop alignment process that reduces manual intervention and accelerates the imaging setup.
3Area of stationary object
If the test subject is required to move their eye or the imaging system is manually repositioned to capture wide-area cornea images, then the imaging coverage is improved, but the discomfort and burden on the test subject increase
Solution Approach 1:
The patent replaces the mechanical approach of moving the entire imaging system or requiring eye movement with an optical-sensing approach. The system uses curvature information to calculate and adjust only the Z-direction position of the imaging optical system, maintaining a fixed imaging position while achieving wide-area coverage through intelligent positioning rather than physical displacement.
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 faster and more accurate imaging of the corneal endothelium by directly aligning the imaging axis with the normal vector of the endothelium, reducing the time and burden required for imaging and improving image clarity, especially in areas with significant curvature differences.
Implementation Method 1
direct a slit beam of illumination light (slit light flux) from an illumination optical system into the cornea of the eye under examination at an angle and receive the light reflected from the cornea by an imaging optical system
Data Source
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AI summary
A cornea imaging apparatus (10, 140, 150) including: a collimation axis holding mechanism (28); an imaging mechanism (32); a Z-direction actuating means (94, 98); an X-direction actuating means (90, 98) and a Y-direction actuating means (92); an inclination angle changing means (96, 160) that changes an inclination angle of an imaging center axis of the imaging mechanism (32) against a collimation axis of an eye under examination; an endothelial configuration computing means (14, 88) that determines a corneal endothelial configuration; and a normal vector computing means (14) that determines a normal vector direction at a given imaging position of the corneal endothelial configuration, wherein at the imaging position, the inclination angle and positions in the Z and X directions are set adjusted so as to align the imaging center axis of the imaging mechanism (32) with the normal vector direction determined by the normal vector computing means (14).