Ophthalmologic Apparatus for Tear Film Lipid Layer Classification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for diagnosing dry eye disorders face challenges in reliably quantifying tear film abnormalities and classifying dry eye types due to low brightness contrast in interference fringes and difficulties in determining dry spot regions and break-up times.
Innovation Solution
An ophthalmologic apparatus with an optical system for projecting illumination light onto the tear film lipid layer, imaging the reflected light, and processing images to measure the movement speed and break-up time of the tear film lipid layer, which are used to classify dry eye types on a two-dimensional map.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional methods are used to measure interference fringes, then the measurement process is simple, but the brightness contrast is low and reliable quantification is difficult
Solution Approach 1:
The patent introduces a reference region with known optical path length as an intermediary to enable accurate measurement. By comparing the interference pattern in the measurement region against the reference region, the system can quantify tear film abnormalities reliably without requiring complex absolute measurements
Solution Approach 2:
The patent measures changes in optical path length as a parameter to detect tear film abnormalities. By tracking the variation in optical path length over time or between regions, the system achieves reliable quantification of tear film stability and composition changes
2Measurement precision
If dry spot region changes are measured over time, then tear film stability can be evaluated, but it is difficult to determine the dry spot and quantification is difficult
Solution Approach 1:
The patent replaces manual visual assessment of dry spots with automated optical measurement. By using interference patterns and optical path length analysis, the system objectively detects and quantifies dry spot regions without relying on subjective human judgment
Solution Approach 2:
The patent creates an optical copy of the tear film structure through interference patterns. This optical representation allows precise measurement of dry spot regions by analyzing the interference fringes, which encode information about tear film thickness and uniformity
3Reliability
If interference pattern intensity is measured, then tear film abnormality can be evaluated, but the brightness contrast is low
Solution Approach 1:
The patent uses a reference region with known optical properties as an intermediary to enhance the effective contrast. By comparing measurement regions against the reference, subtle variations in tear film that would be imperceptible in absolute intensity become clearly distinguishable through differential measurement
4Loss of information
If conventional classification methods are used, then diagnosis can be performed, but detailed classification of dry eye types cannot be determined
Solution Approach 1:
The patent segments the classification of dry eye into multiple distinct types based on different measurement parameters. By dividing the diagnostic space into categories such as aqueous tear deficiency, evaporative dry eye, and mixed types, the system provides detailed classification without requiring overly complex measurement systems
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
This approach allows for reliable quantitative measurement of tear film abnormalities and accurate classification of dry eye types, facilitating diagnosis and treatment based on the measured parameters.
Implementation Method 1
imaging means for receiving reflected light from the tear film lipid layer and capturing an image of the tear film lipid layer
Implementation Method 2
measuring the intensity of an interference pattern due to interference of reflected light on the obverse and reverse surfaces of the tear film lipid layer
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An illumination light is projected onto a tear film lipid layer on a cornea of an eye to be examined, and the reflected light is received and the tear film lipid layer is imaged. The image of the tear film lipid layer that has been captured is processed, and the initial spread speed H' of the tear film lipid layer at the time the eyelid has been opened is measured. The image of the tear film lipid layer that has been captured is processed, and the time until the tear film lipid layer is broken up after the eyelid has been opened and a dark area T appears is measured. The appearance time of the dark area is plotted on the Y-axis and the initial spread speed H'(0) of the tear film lipid layer is plotted on the X-axis, and the type of dry eye is classified. In such a configuration, since the type of dry eye can be classified and determined, diagnosis and treatment in accordance with the type of dry eye are made possible.