Development of a new analytical method for the electrocardiogram using short-time first Fourier transforms

Area of Science:

• Cardiology
• Biomedical Engineering
• Signal Processing

Background:

• Detecting minute electric potentials within the QRS complex is crucial for understanding cardiac electrical activity.
• Existing methods may require signal averaging, limiting real-time analysis.
• High-frequency sampling and advanced signal processing offer potential improvements.

Purpose of the Study:

• To develop and evaluate a new frequency domain method for detecting subtle electric potentials within the QRS complex.
• To assess the capability of the method in analyzing cardiac electrical activity without signal averaging.
• To explore its potential for evaluating the process of excitement in various heart diseases.

Main Methods:

• A novel frequency domain method utilizing short-time Fourier Transforms (SFFT) and high-frequency sampling (oversampling).
• Weighted, running average processing of 15,000 data points to reduce low-frequency components.
• Frequency analysis of 160 ms segments including the QRS complex using SFFT computation.

Main Results:

• The SFFT method improved frequency resolution through oversampling.
• It enabled the detection of internal QRS complex structures without signal averaging.
• Peak electric potentials were identified across X, Y, and Z axes in normal subjects.

Conclusions:

• The developed SFFT method is effective for detecting minute electric potentials within the QRS complex.
• It offers a valuable tool for analyzing cardiac electrical activity, particularly in conditions requiring detailed QRS complex evaluation.
• This technique shows promise for assessing the process of excitement in various heart diseases.