STFT for Heart Rate Variability

[karlisk]

Hi,

I am a new Biomedical Toolkit user and I have just started to explore the Time-Frequency analysis posibilities for HRV. I was trying to create a VI that replicates the functionality of the STFT Spectogram in the Heart Rate Variability Analyzer, but somehow the frequency resolution of my spectrogram is much worse. I guess, that is because my spectrogram shows frequencies from 0 to 256 Hz, while the Heart Rate Variability Analyzer's spectrogram has values only from 0 to 1 Hz. However, the settings appear to be the same.

Can you please tell me how can I get the same frequency resolution in the range 0 - 1 Hz as the Heart Rate Variability Analyzer's spectrogram?

Thanks!

In the attached picture you can see the settings and results of my VI and the Biomedical Toolkit. The input data are the same.

[Haier_Xu]

Hi，

The VI you created just read one row data from the input text file. You should use the all rows output terminal of Read FromSpreadsheet File VI. You could modify it according to the attached VI.

For more information about HRV analyzer, please refer to the HRV Analyzer example under National Instruments\LabVIEW 2012\examples\Biomedical\Biosignal folder.