Wavelet Feature Extraction for MRS PTSD and mTBI Diagnosis

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Solution Overview

Problem

Current methods for diagnosing Post-Traumatic Stress Disorder (PTSD) and mild Traumatic Brain Injury (mTBI) using magnetic resonance spectroscopy (MRS) rely on assumptions about known metabolites and lack effective non-invasive techniques for identifying biochemical signatures.

Innovation Solution

The use of wavelet-based feature extraction from proton-based MRS signals to identify biomarkers for PTSD and mTBI, employing wavelet decomposition and Sequential Forward Selection to select discriminative features for classification, allowing for the development of diagnostic classifiers that can distinguish between different health states without assuming the presence of specific metabolites.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional MRS analysis methods are used that assume known metabolites and use pre-defined basis functions, then the analysis process is simpler and more straightforward, but the ability to identify new biochemical signatures and biomarkers is limited

Engineering Contradiction:
Improveability to identify biochemical signaturesVSAvoidcomplexity of analysis method
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts features directly from the MRS signal spectrum without assuming knowledge of specific metabolites. Wavelet-based feature extraction is applied to the raw spectral data to identify patterns and biomarkers that are not tied to pre-defined metabolite models, thereby discovering new biochemical signatures while maintaining analytical rigor

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the traditional mechanical approach of fitting pre-defined basis functions with an automated computational approach using wavelet transforms and machine learning algorithms. This substitution enables the system to automatically identify biomarkers without human expertise in metabolite identification, resolving the contradiction between simplicity and discovery capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If wavelet-based feature extraction is used to identify biomarkers without assuming specific metabolites, then the ability to discover new biochemical signatures is improved, but the complexity of data analysis and processing increases

Engineering Contradiction:
Improveability to identify different biomarkersVSAvoidcomplexity of feature extraction process
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a universal wavelet-based feature extraction framework that can identify biomarkers across different conditions (PTSD, mTBI, and their combination) without requiring condition-specific analysis methods. The same computational pipeline adapts to different datasets and clinical scenarios, providing versatile biomarker discovery while maintaining a consistent analytical approach

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

Solution Approach 2:

The system performs self-service through automated feature extraction and selection algorithms that do not require manual intervention or expert knowledge. The wavelet transform and sequential forward selection procedures automatically identify relevant biomarkers from the MRS data, reducing the need for complex manual analysis while maintaining high adaptability across different clinical conditions

Inventive Principle:
Principle #25Self-service

3Reliability

If comprehensive MRS data analysis is performed to distinguish between PTSD, mTBI, and their combination, then the diagnostic accuracy is improved, but the time and computational resources required increase

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidtime for data analysis
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary wavelet-based feature extraction to transform the raw MRS spectral data into a compact set of informative features before classification. This preprocessing step reduces the dimensionality of the data while preserving the essential diagnostic information, enabling faster and more efficient classification of PTSD, mTBI, and their combination with high accuracy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the complex diagnostic task into distinct stages: wavelet feature extraction from the MRS spectrum, sequential forward selection of discriminative features, and final classification. This segmentation allows each stage to be optimized independently, reducing overall computational time while maintaining diagnostic accuracy across multiple conditions

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Achieves accurate classification rates of nearly 80% in cross-validation, demonstrating the effectiveness of MRS as a non-invasive means for measuring biochemical signatures associated with PTSD and mTBI, and providing a diagnostic tool for differentiating between healthy and affected individuals.

Implementation Method 1

MRS (magnetic resonance spectroscopy), also known as NMR (nuclear magnetic resonance) spectroscopy, is widely used to identify relative abundance of isotopes of atoms, with unpaired nuclear spin, in molecules. The isotopes of interest in biochemistry, biology and organic chemistry include hydrogen-1, which is the most predominant, carbon-13, oxygen-17, sodium-23, and phosphorus-31, which are spin-aligned in their lowest stable quantum states in the presence of a magnetic field. If exposed to a sweep of radio frequency (RF) waves of the electromagnetic spectrum (e.g., around 500 megaHertz (MHz)), these nuclei can absorb energy from the electromagnetic field and hop (i.e., flip the spin orientation) to the next higher energy quantum state.

Methodology Applied
Scientific EffectNuclear magnetic resonance: Magnetic Field

Implementation Method 2

The frequency at which a nucleus flips to the higher state varies according to the magnetic field experienced by the nucleus which in turn depends on the atom and its functional group (neighboring atoms). The dependence of the RF absorption frequency on the functional group allows H-atoms (and others listed above) in a molecule to be separated according to functional group. For example in benzyl alcohol, the H-atoms in the benzyl group, alkyl group and hydroxyl group can all be identified separately using MRS.

Methodology Applied
Scientific EffectChemical shift: Magnetic Field

Data Source

PatentUS11529054B2Method and system for post-traumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) diagnosis using magnetic resonance spectroscopy
Publication Date: 2022.12.20 THE CHARLES STARK DRAPER LABORATORY INC
  • US11529054B2 patent drawing
  • US11529054B2 patent drawing
  • US11529054B2 patent drawing

AI summary

A MRS (magnetic resonance spectroscopy or nuclear magnetic resonance NMR)-based PTSD (post-traumatic stress disorder) and mTBI (mild traumatic brain injury) diagnostic system and method uses MRS signals, already pre-processed by the MRS scanner software. The signals are collected in vivo from specific regions of the brain. A wavelet decomposition is applied to the MRS signals, and the amplitude of the wavelet coefficients and their location in the MRS signals are used as features for training diagnostic classifiers of disease states. These classifiers are identified through analysis of features of individuals whose health status is known. Once the classifiers are trained, patients can be diagnosed by using the same wavelet features extracted from in vivo MRS scans of their brain regions.