Classifier Using Union Labels for Cross-Modality Dental Image Analysis

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Solution Overview

Problem

Conventional technologies fail to effectively utilize information from images captured by one imaging modality when viewing images from a different modality, and similarly, they struggle to leverage information from measurements by one type of sensor when presented with data from another type of sensor.

Innovation Solution

The use of union labels, which are calculated by performing a union operation on labels from different imaging modalities or sensor measurements, allowing a classifier to exploit knowledge from one type of image or sensor measurement to classify images or measurements from another type, even if the modalities or sensors are different.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional classification methods are used separately for each imaging modality, then the classification process is simple and straightforward, but the classifier cannot exploit knowledge from one imaging modality to improve classification of another modality

Engineering Contradiction:
Improvecross-modality knowledge exploitationVSAvoidclassification system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple imaging modalities and their corresponding labels into a unified training framework. By combining labels from different modalities (e.g., fluorescent biomarker images and white light images) into joint training sets, the classifier learns to exploit knowledge across modalities, enabling improved classification performance without requiring complex separate processing systems for each modality.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If human experts label all images manually, then the labeling accuracy is high, but the time and cost required for labeling increases significantly

Engineering Contradiction:
Improvelabeling accuracyVSAvoidlabeling time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies partial human expert labeling combined with computer vision algorithms. Instead of requiring human experts to label all images, the system uses computer vision to generate initial labels and applies human expert labeling only to a subset of images (e.g., 10-50% of the training set). This partial action approach maintains high labeling accuracy while significantly reducing the time and cost associated with complete manual labeling.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If high-radiation or expensive imaging methods are used for all diagnostic cases, then the diagnostic accuracy is improved, but the cost and patient exposure to radiation increases

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidradiation exposure and cost
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent uses a trained classifier as an intermediary to bridge between lower-cost imaging modalities and higher-cost or higher-radiation modalities. The classifier, trained on joint data from multiple modalities including high-radiation CT scans, can infer diagnostic information from lower-radiation MRI or ultrasound images, thereby reducing patient radiation exposure and cost while maintaining diagnostic accuracy through the intermediary classification system.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS11308355B2Methods and apparatus for classification
Publication Date: 2022.04.19 MASSACHUSETTS INST OF TECH
  • US11308355B2 patent drawing
  • US11308355B2 patent drawing
  • US11308355B2 patent drawing

AI summary

A human expert may initially label a white light image of teeth, and computer vision may initially label a filtered fluorescent image of the same teeth. Each label may indicate presence or absence of dental plaque at a pixel. The images may be registered. For each pixel of the registered images, a union label may be calculated, which is the union of the expert label and computer vision label. The union labels may be applied to the white light image. This process may be repeated to create a training set of union-labeled white light images. A classifier may be trained on this training set. Once trained, the classifier may classify a previously unseen white light image, by predicting union labels for that image. Alternatively, the items that are initially labeled may comprise images captured by two different imaging modalities, or may comprise different types of sensor measurements.