How to Use the New ECG Feature Extractor VI

[ZJ.Gu]

Use the ECG Feature Extractor Express VI to analyze the features of an input ECG signal.

New features in 2013 include:

• ST segment analysis
• New algorithm which can provide more accurate feature extraction results

The ECG Feature Extractor Express VI is a polymorphic VI containing 4 instances: Waveform QRS Only, Array QRS Only, Waveform All Features and Array All Features. Different from 2012 version, you need to input both an ECG signal and a raw ECG signal for all of these instances. ECG is the preprocessed ECG signal, which is used for the detection of the QRS complex. raw ECG is the raw ECG signal or de-noised signal, which is used for the extraction of other features, such as amplitude-related features.

The ECG feature cluster output contains 3 new elements in 2013: ST level, P wave? and T wave?. ST level indicates the ST level of the current beat. P wave? and T wave? indicate whether the current beat contains a valid P wave or T wave, respectively.

The QRS detector parameters and feature extractor parameters have been redesigned for the new algorithm. In QRS detector parameters, you can set the freq bands, QRS onset and QRS offset according to the QRS wave type of your signal. In feature extractor parameters, you can set the PR interval and QT interval to configure how the application refines the P wave and T wave, respectively.

Following is an example of how to use the ECG Feature Extractor Express VI. The example is similar to that in the 2012 version of the Biomedical Toolkit.

[dinamedy]

Hi,

Can we download or upgrade to this 2013 beta version please ?

Regards.

[ZJ.Gu]

Sorry that the beta is for selected testers. We will release 2013 version in NI Week 2013 (August).

Thanks!

ZJ Gu

[dinamedy]

Hi,

Is it possible to have technical docs or links on how the ECG Feature Extractor VI works ? which techniques does it use  to detect QRS, P and T wave, ST level ? does it perform a baseline wander removal, filtering of the signal ? does it use wavelet decomposition technique ?  

Regards.

[ZJ.Gu]

If you install the toolkit, from help, you could see the reference list. And it should be noted that what you said like baseline wander removal, filtering, are all considered as preprocessing stages. It is a separate step before ECG feature extraction VI runs.

Thanks!