Robust Clustering via PCA and Consensus Ensemble for Microarray Data

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Solution Overview

Problem

Current methods for analyzing microarray data in cancer research are hindered by noise and heterogeneity, making it difficult to identify robust and homogeneous cancer phenotypes and their corresponding gene markers, which are essential for understanding disease progression and developing effective treatment protocols.

Innovation Solution

The method employs Principal Component Analysis (PCA) to identify patterns of variation in data, followed by consensus ensemble clustering to normalize and select attributes contributing most to the variation, and then applies clustering techniques to identify robust clusters and gene markers, ensuring stability and accuracy across different data perturbations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional clustering methods are used on microarray data, then the analysis process is simple, but the identification of robust clusters is compromised due to noise and heterogeneity

Engineering Contradiction:
Improverobustness of cluster identificationVSAvoidcomplexity of analysis method
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The method segments the complex task of robust cluster identification into multiple components: (1) generating multiple perturbed versions of the data set, (2) performing clustering on each version, (3) computing consensus scores to identify stable clusters. This segmentation allows the system to handle noise and heterogeneity systematically while maintaining manageable computational complexity at each step.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The method performs preliminary actions by generating multiple perturbed versions of the data set before final cluster identification. These perturbations (through subsampling, bootstrapping, or adding noise) are applied in advance to create a ensemble of data versions that will be clustered separately, allowing the consensus step to filter out noise-induced variations and identify truly robust clusters.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If consensus ensemble clustering is applied to identify robust clusters, then clustering accuracy is improved, but computational time increases

Engineering Contradiction:
Improveaccuracy of cluster identificationVSAvoidcomputational time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The method applies partial action by performing clustering on a limited number of perturbed data versions rather than exhaustively sampling all possible perturbations. By selecting a manageable number of perturbations (e.g., 10-50 versions) that sufficiently capture data variability, the method achieves robust cluster identification without incurring excessive computational costs associated with exhaustive enumeration.

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If principal component analysis is used to identify patterns of variation, then data dimensionality is reduced, but information about subtle disease signals may be lost

Engineering Contradiction:
Improvedata dimensionalityVSAvoidsubtle disease signals
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The method applies parameter changes by varying the number of principal components retained and the degree of data perturbation applied. By adjusting these parameters, the system can balance dimensionality reduction with preservation of subtle signals - retaining enough components to capture major variation patterns while performing consensus clustering robustly, or using milder perturbations to preserve subtle disease-related variation that might be lost with aggressive dimensionality reduction.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS8165973B2Method of identifying robust clustering
Publication Date: 2012.04.24 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US8165973B2 patent drawing
  • US8165973B2 patent drawing
  • US8165973B2 patent drawing

AI summary

A method of finding robust clusters comprises the use of principal component analysis and consensus ensemble clustering. In another aspect, the method may comprise normalizing a data set; identifying attributes of the data set that contribute to most of variation in the normalized data set; selecting data having the attributes that contribute to most of variation in the normalized data set; identifying a plurality of clusters from the selected data using consensus ensemble clustering; and identifying robust clusters from the plurality of clusters. The method can be used in healthcare and life science.