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Analyzing HRV in AcqKnowledge

Single-epoch HRV–Spectral Analysis

When to use: "When analyzing a single user-defined area of data"

 

Highlight the area of data you want to analyze and follow the steps below

  • Select "Analysis" from the top menu bar

  • Under "HRV and RSA", select "Single-epoch HRV - Spectral"

  • ​Select whether you want to analyze the data based on "QRS detector" or "Events" 

    • "QRS detector" will automatically determine where all waveforms are located in the selected data and compare them​

    • "Events" should only be used if event markers were placed in the data

  • Under "Output", check the "Show interpolated tachogram" box along with any other data you would like to extract

    • I would recommend selecting "Paste to journal" just to be sure you don't loose the analysis

  • Select "OK"

  • Select "Copy to Clipboard", then navigate to an Excel sheet and paste the data

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For a visual walkthrough of this, skip to timestamp 38:17 of the video below

Multi-epoch HRV and RSA – Spectral
When to use: When analyzing "specified time slices along an ECG waveform, whether by markers, fixed-time intervals, or focus areas."

For this tutorial, I will be showing this analysis done with focus areas. 

  • Create your focus areas

    • Using. the I-beam cursor, highlight your first area of interest​

    • ​Select the "+" button in the top right hand corner of the menu bar and name the focus area

      • If this button is not visible on the menu bar, go to "Display" > "Show" > check "Focus Areas Bar"​

    • Repeat the process for all areas you want to analyze/compare

focus area_edited.jpg

  • Select "Analysis" from the menu bar

  • Under "HRV and RSA", select "Multi-epoch HRV and RSA - Spectral"

  • In the dropdown "Extract HRV and RSA for:" select "Focus areas"

  • Select your desired "Output type"​
    • If choosing "Text Only", your analysis will be pasted in the Journal​
  • Select "OK"

For a visual walkthrough of this, skip to timestamp 43:39 of the video below

Multi-epoch HRV and RSA – Statistical
When to use: When analyzing "statistical measures of heart rate variability in user-specified time intervals These measures (RMSSD, SDSD, and pNN50) can be extracted by fixed time intervals, time between event boundaries or focus areas."

For this tutorial, I will be showing this analysis done with time intervals. 

  • Select "Analysis" from the menu bar

  • Under "HRV and RSA", select "Multi-epoch HRV - Statistical"

  • Input how long you want each analyzed segment to be in the "Epoch width" box and select "OK"

Multi-epoch statistical.jpg

If you choose to output results to a spreadsheet, an Excel sheet will open with data like the image on the right

  • RMSSD: the root mean squared of successive NN-interval differences

  • SDSD: the standard deviation of successive differences in RR intervals

  • pNN50: Percentage of successive RR intervals that differ by more than 50 ms

excel.jpg

You may notice that after this analysis, each wave in your data will now be labeled with all of its points in the QRS complex.

qrs.jpg

For a visual walkthrough of this, skip to timestamp 47:01 of the video below

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