g.BSanalyze: ECG-toolbox part I

g.BSanalyze: ECG-toolbox part I

g.ECGtoolbox  is a software package for ECG data processing and analysis. — The investigation of patterns and signal features of ECGs allows to observe noninvasively brain and heart functions and disfunctions.

The graphical user interface for g.ECGtoolbox  enables you to investigate all important time and frequency domain features of your electrocardiogram (ECG) data such as RR intervals or HRV maps. You can load and save your preferred processing steps as a script program and automatically process your data in batch mode.

QRS complex detection

Starting from noisy raw ECG data, QRS complexes are automatically detected and indicated in the data editor with attribute QRS. An intelligent algorithm assigns the attribute QRSBAD to R-peaks that are not detected securely. These markers can now be corrected visually or (if necessary) excluded from further analyses. Time courses of tachogram and RR-intervals can also be displayed for visual inspection.

 

Time Domain ECG Features

  • Time domain measure s such as the evolution of the mean RR intervals NN50, the number of RR intervals differing by more than 50 ms, ...
  • Segmented Measures  such as SDANN, the standard deviation of the averages of RR intervals in all segments of the recording, ...
  • Geometric Measures  such as HRVindex yielding the total number of RR intervals divided by the number of RR intervals, ...

 

Frequency Domain ECG Features

ECG data analysis in the frequency domain allows you to investigate heart rate variability oscillations at different frequencies.These oscillations are originated by different physiological systems. The parasympathetic and sympathetic systems modulate the heart rate variability. High frequency oscillations (about 0.2-0.35 Hz) are vagally mediated and low frequency oscillations (around 0.1 Hz) are due to both parasympathetic and sympathetic systems. The respiratory sinus arrhythmia (RSA) is vagally mediated and has a frequency synchronous to the respiratory cycle (between 0.2 and 0.35 Hz). Very low frequency components are associated with slow regulation mechanisms such as humoral and thermoregulation factors.

  • Absolute Measures  such as the 4 main spectral components (ULF, VLF, LF, HF) are extracted from a calculated spectrum, ...
  • Relative Measures  such as the ratio of LF/HF or LF normalized by the total power TP, ...

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Time-Frequency ECG Analysis

Example: HRV maps

To simplify the data analysis and interpretation of the ECG data HRV maps allow to estimate the PSD (power spectral density) for a certain segment. Then the segment is shifted by a specific stepsize and the PSD is calculated again. This yields a comprehensive time-frequency analysis plot over the recording time. High power values are indicated in red, low power values are shown in blue.

In addition to the time frequency plot, the time course of the spectral components ULF, LF, HF, VHF are also displayed in the protocol

Product Highlights

  • Robust QRS complex detection
  • Overlayed QRS detection result with raw ECG
  • Edit and manipulate QRS detection result
  • Time domain measures and statistics
  • Geometric measures: HRVindex
  • Absolute measures of spectral power distribution (ULF, VLF, LF, HF)
  • Relative measures of spectral power distribution (LFnorm, HFnorm, LF/HF)
  • HRV time-frequency maps

See some related products

Software

product no.: 0101 read more g.BSanalyze: Specs & Features — advanced biosignal data processing toolbox; multi-modal Off-line Biosignal Analysis under MATLAB®
product no.: 0104b read more g.BSanalyze: ECG-toolbox part II — specialised ECG processing toolbox for single beat classification and analysis

Related Media and Documents

g.BSanalyze

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gECGtoolbox — 10/11/2011 — 1.16 MB