Sequential CNN Nuclei Segmentation for Overlapping Cell Clusters

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current machine learning systems struggle to accurately segment cell nuclei in digital pathology images, particularly in cases of overlapping clusters, due to intensity variations and noise, which hinders trustworthiness and clinical adoption.

Innovation Solution

A method involving sequential application of two different convolutional neural networks (CNNs) for cell nucleus segmentation, where a first CNN identifies center locations and a second CNN determines nuclear boundaries, using UNet architecture and patch-based processing to handle overlapping nuclei.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional single-stage CNN segmentation is used, then the system is simpler and faster, but segmentation accuracy deteriorates in overlapping nuclei clusters

Engineering Contradiction:
Improvesegmentation accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the segmentation task into two sequential stages: (1) a first CNN identifies nucleus centers and generates initial masks, and (2) a second CNN refines boundaries by processing patches around detected centers. This two-stage segmentation approach resolves the contradiction by improving accuracy in overlapping regions while maintaining computational feasibility through staged processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first CNN performs preliminary detection of nucleus centers and generates initial segmentation masks before the second CNN refines boundaries. This preliminary action allows the system to identify potential nuclei locations and handle overlapping regions more effectively, improving overall segmentation accuracy without requiring the entire system to be overly complex.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If deep learning models are used to improve segmentation accuracy, then measurement precision improves, but interpretability and trustworthiness worsen due to black box nature

Engineering Contradiction:
Improvesegmentation accuracyVSAvoidinterpretability
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

By segmenting the segmentation task into two interpretable stages (center detection + boundary refinement), the patent makes the deep learning process more transparent. Each stage has a clear, distinct function that can be independently validated, reducing the black box effect while maintaining high accuracy through sequential processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first CNN acts as an intermediary that detects nucleus centers and generates initial masks, which then serve as input for the second CNN's boundary refinement. This intermediary stage breaks down the complex single-stage problem into manageable steps, improving interpretability while maintaining accuracy through coordinated multi-stage processing.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If automated segmentation is implemented to improve productivity, then processing speed increases, but reliability deteriorates due to difficulty in handling overlapping nuclei and intensity variations

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidsegmentation reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The two-stage segmented approach improves reliability by dedicating the first stage to robust center detection (handling intensity variations) and the second stage to precise boundary refinement (handling overlaps). This division of labor maintains automated processing efficiency while significantly improving reliability in challenging regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system processes multiple patches around detected nucleus centers, creating local copies of image regions for detailed boundary analysis. This copying approach allows the second CNN to focus computational resources on specific regions of interest, improving reliability for individual nuclei while maintaining overall processing efficiency through selective refinement.

Inventive Principle:
Principle #26Copying

Data Source

PatentUS12632964B2Sequential convolutional neural networks for nuclei segmentation
Publication Date: 2026.05.19 PROVINCIAL HEALTH SERVICES AUTHORITY
  • US12632964B2 patent drawing
  • US12632964B2 patent drawing
  • US12632964B2 patent drawing

AI summary

Methods and apparatus for segmenting cell nuclei in medical images apply first and second trained machine learning algorithms. The first trained machine learning algorithm processes a medical image to provide center locations of cell nuclei depicted in the image. The second machine learning algorithm processes each of a plurality of patches of the image. Each of the patches correspond to one of the plurality of center locations. Processing each patch yields a nuclear boundary corresponding to the corresponding one of the center locations. The methods and apparatus allow associating individual pixels of the image with one or more than one nuclei and have been shown to be effective for instance segmentation of nuclei in clusters of overlapping cell nuclei.