Retinal Landmark Outlier Detection for Reliable Image Annotation

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Solution Overview

Problem

Machine learning algorithms used for predicting landmark features in retinal images may fail due to occlusions or imaging artifacts, leading to inaccurate predictions that can adversely affect downstream data processing operations.

Innovation Solution

An ocular imaging system that includes a landmark location prediction module using machine learning algorithms to predict landmark features, accompanied by a distance metric evaluation module and an outlier detector to alert users of unreliable predictions, allowing for manual correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If color segmentation is used to differentiate retinal layers, then layer identification is improved, but color distortion and inaccurate representation occur

Engineering Contradiction:
Improvelayer identification accuracyVSAvoidcolor distortion
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The retinal image is segmented into distinct layers (nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer) based on intensity variations and anatomical boundaries. This segmentation enables precise layer identification while preserving the original grayscale color information, avoiding the color distortion problems of color segmentation methods.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If traditional processing methods are used, then processing speed is maintained, but diagnostic accuracy and detail visibility are insufficient

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidprocessing efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The method performs preliminary actions including noise reduction, contrast enhancement, and layer segmentation before final image presentation. By pre-processing the image to enhance layer boundaries and reduce noise, the system achieves both high diagnostic accuracy and efficient processing, as the enhanced image requires less post-processing analysis.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary processing stage that transforms the original retinal image into an enhanced representation with clearly defined layers. This intermediary image serves as a bridge between the raw input and diagnostic interpretation, preserving diagnostic accuracy while enabling faster analysis through improved visual differentiation of layers.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If multiple processing steps are applied to enhance image quality, then diagnostic accuracy is improved, but processing complexity increases

Engineering Contradiction:
Improveimage qualityVSAvoidprocessing steps
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple processing functions (noise reduction, contrast enhancement, layer segmentation, and boundary detection) into a unified processing pipeline. By combining these steps into an integrated system that operates simultaneously rather than sequentially, the method achieves high image quality while reducing overall processing complexity and computational overhead.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4150504B1Retinal image processing
Publication Date: 2026.05.06 OPTOS PLC
  • EP4150504B1 patent drawingFigure 1
  • EP4150504B1 patent drawingFigure 2
  • EP4150504B1 patent drawingFigure 3

AI summary

An apparatus for generating an alert indicating an unreliability in a location of a landmark feature in a retinal image predicted by a machine learning algorithm, comprising: a receiver module which receives the predicted location; a probability indication determining module which uses the predicted location and a mixture model, which comprises a probability distribution of a landmark feature location and is based on determined locations of the landmark feature in retinal images having a plurality of retinal image classes, to determine, for each class, a respective probability indication indicating a probability that the retinal image belongs to the class; an outlier detector module which uses the probability indications to determine whether the retinal image is an outlier belonging to none of the classes; and an alert generator module which generates, when the retinal image belongs to none of the classes, an alert indicating unreliability of the predicted location.