Parametric ECG Wave Analysis Using Cosine Phase Model

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Solution Overview

Problem

Existing methods for analyzing cardiac activity signals, such as Fourier decomposition and wavelet or Gaussian modeling, require a large number of parameters and lack physical meaning, making it difficult to characterize ECG signals effectively.

Innovation Solution

A method that analyzes cardiac activity signals by decomposing them into a sum of elementary waves expressed as x(t) = x0 + x1 cos(Φ(t)), where Φ(t) is the phase function, allowing for characterization with a small number of parameters that carry physical meaning and represent the shape of the signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Fourier decomposition is used to analyze ECG signals, then the frequency components of the signal can be described, but a large number of coefficients are required and they lack physical meaning

Engineering Contradiction:
Improvesignal characterization accuracyVSAvoidnumber of parameters
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transforms the ECG signal representation from Fourier coefficients to a parametric model with physically meaningful parameters (amplitude, duration, morphology parameters). This changes the parameter space from abstract mathematical coefficients to clinically interpretable quantities that directly describe wave characteristics.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts and models only the essential characteristics of ECG waves (P, QRS, T waves) using a simplified parametric equation, separating the critical information from the redundant details that Fourier decomposition captures but cannot interpret meaningfully.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If wavelet or Gaussian modeling is used to decompose ECG signals, then the signal can be modeled, but a very large number of parameters are required for sufficient quality

Engineering Contradiction:
Improvemodeling qualityVSAvoidnumber of parameters
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent adopts a cosine-based parametric model with a small set of physically meaningful parameters instead of wavelet or Gaussian models. This parameter transformation achieves reliable ECG wave characterization while dramatically reducing the number of parameters needed for sufficient modeling quality.

Inventive Principle:
Principle #35Parameter changes

3Loss of information

If Fourier decomposition is used, then the distribution of frequency components can be described, but no information is provided on the instants of appearance and wave shapes

Engineering Contradiction:
Improvetemporal and morphological informationVSAvoidparameter interpretability
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent changes from frequency-domain Fourier coefficients to time-domain parametric models that explicitly represent wave instants, shapes, and morphologies. This parameter transformation preserves temporal and morphological information while maintaining mathematical simplicity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2558954B1Method and system for analysing the cardiac activity of a patient and uses thereof
Publication Date: 2019.10.02 CENT NAT DE LA RECH SCI (C N R S)
  • EP2558954B1 patent drawingFigure 1~3
  • EP2558954B1 patent drawing
  • EP2558954B1 patent drawing

AI summary

The invention relates to a method for analysing the cardiac activity of a patient, comprising the following steps: acquisition (20) of at least one electric cardiac signal including at least one elementary signal corresponding to a heart beat; extraction (29), from the elementary signal, of at least one elementary wave having a general form that can be expressed as x(t) = x 0 + x 1 cos(F(t)), in which F(t) is the phase of the elementary wave; and analysis (30) of the elementary wave, comprising steps consisting in determining an expression of a phase equation, formula (I), of the elementary wave and determining an expression of phase F(t) of the elementary wave as a function of parameters measuring the anharmonicity of the elementary wave and the morphology thereof from functions pcosn and psinn defined by formula (II).