Self-Supervised Puzzle Training for Medical Image Analysis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional machine learning models require large amounts of labeled training samples and expert annotations for supervised learning, making them impractical for image analysis tasks, especially when resources are scarce.

Innovation Solution

A self-supervised learning approach is employed where a machine learning model is first trained to solve a puzzle task, such as reassembling shuffled image portions across multiple imaging modalities, and then tuned for a downstream image analysis task using minimal labeled samples, leveraging the Sinkhorn operator to reduce computational burden and learn modality-agnostic representations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional supervised learning is used with large amounts of labeled training data, then model performance is improved, but resource requirements and training time increase significantly

Engineering Contradiction:
Improvemodel performanceVSAvoidlabeled training data
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The model performs self-supervised pre-training on puzzle solving tasks using unlabeled multimodal medical images before fine-tuning on downstream tasks. This preliminary action allows the model to learn useful representations without requiring extensive labeled data, resolving the contradiction between model performance and labeled data requirements

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses self-supervised learning where the model generates its own training signals by solving puzzle tasks (reassembling shuffled image patches) without human annotations. This self-service mechanism eliminates dependency on expensive expert-labeled datasets while still achieving strong performance on downstream medical image analysis tasks

Inventive Principle:
Principle #25Self-service

2Measurement precision

If expert annotations are used for training, then measurement precision is improved, but training cost and time increase

Engineering Contradiction:
Improveannotation accuracyVSAvoidtraining time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The model undergoes preliminary self-supervised training on puzzle solving with synthetic labels generated automatically from image patches. This pre-training phase captures general visual patterns and reduces the time needed for subsequent fine-tuning with expert annotations, effectively resolving the time-accuracy tradeoff

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If multimodal data is processed, then adaptability is improved, but device complexity increases

Engineering Contradiction:
Improvemulti-modality handlingVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system segments the complex multimodal processing task into distinct components: a shared backbone network for feature extraction, modality-specific projection layers, and task-specific heads. This segmentation allows efficient handling of multiple imaging modalities (CT, MRI, PET) without overwhelming system complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The model employs a universal backbone network that processes multiple imaging modalities through a single unified architecture. This multi-functional design achieves adaptability across different modalities while avoiding the complexity of separate specialized models for each modality

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Productivity

If puzzle solving pre-training is performed, then productivity on downstream tasks is improved, but initial training time increases

Engineering Contradiction:
Improvedownstream task performanceVSAvoidpre-training time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The model performs preliminary self-supervised pre-training on puzzle solving tasks using automatically generated labels from shuffled image patches. Although this initial phase requires time, it establishes strong foundational representations that significantly accelerate convergence and improve performance on downstream medical image analysis tasks, resolving the productivity-time contradiction

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11631181B2Multimodal self-supervised learning for image analysis
Publication Date: 2023.04.18 SAP SE
  • US11631181B2 patent drawing
  • US11631181B2 patent drawing
  • US11631181B2 patent drawing

AI summary

A machine learning model may be trained on a first task of puzzle solving before being tuned on a second task of image analysis. The training of the machine learning model may be self-supervised whereas the tuning of the machine learning model may be supervised. The training data may include a puzzle generated to include multiple imaging modalities. The puzzle may be generated by shuffling a position of the pieces forming an original image. The machine learning model may be trained to perform the first task by reassembling the pieces in the puzzle to generate a reconstruction of the original image. Upon being trained to perform the first task and tuned to perform the second task, the machine learning model may be deployed to perform the second task. The second task may be an image segmentation task such as tumor segmentation and a regression task such as survival prediction.