On-line ECG Analysis

[mtetlow]

My research involves a lot of ECG analysis, so I'm looking into buying the biomedical toolkit. Does it have the functionality to do on-line ECG analysis while data is still being acquired? Some of our experiments get very long and it would be great to be able to do some basic analysis at the same time.

Thanks,

Megan

[Xuesong_Liu · Accepted solution]

Yes. You can use Biomedical Toolkit to perform on-line ECG feature analysis.

ECG Feature Extractor in Biomedical Workbench could extract and show ECG features and save them with the original signal when acquiring data.

[josborne]

I was just about to ask this exact same question.  A lot of the examples I have seen involve analyzing one static chunk of data.  I want to analyze my incoming ECG on-the-fly and extract R waves as quickly as possible.

Anyone got a simple example VI for this?

[TEP]

As with josborne, I would also be interested in seeing an example VI that does on-line ECG analysis.

[Xuesong_Liu]

Hi

Actually we have an example of online ECG Feature Extraction. You can click Help->Find Examples... in LabVIEW and search for ECG Feature Extractor.

Here is a document of how to write such a ECG Feature Extractor:https://decibel.ni.com/content/docs/DOC-23689

This example reads ECG signal from file block by block, you can also replace it with a Biosignal DAQ Express VI if you want to perform analysis directly to the signal acquired from DAQ.

[Camelia]

Hello, i am new on this forum, and i need an EKG.vi. Can you help me please!!!!!!

[jschuller]

When I tried to replace the Read Biosignal to the Biosignal DAQ VI I could not figure out how to fix this error message: Duration input is not an integer multiple of dt. Value was coerced to nearest integer multiple of dt.

I would like to analyze the data coming in from a DAQ, but I am having difficulties with this error.

[Xuesong_Liu]

If you are modifying the ECG Feature Extractor example, i think this error happens inside the Waveform Delay.vi. This VI is to compensate the delay caused by filtering, by removing the first several points of the filtered signal (the number of removed points equals to the half of the filter length). When you drop a BIosignal DAQ Express VI, the default block size is 0.03s, which may be shorter than half the filter length. Thus the Waveform Delay.vi returns an error because there are not enough points to be removed. You can try to increase the block size to solve this problem.

[jschuller]

Thank you for the suggestion, that did fix the error!

I am still however unable to acquire any type of ecg feature stats with the live signal, everything comes back zero as if the information does not reach the calculation stage.

Is there any general concept I am missing?

Thanks

[Xuesong_Liu]

The example reads ECG signal from a file and analyzes the signal in a loop. The loop will continue until the file end reached. The statistics of detected features will be calculated after that. When you replace the Read Biosignal Express VI with a Biosignal DAQ Express VI, the loop will never stop unless you wire a stop button to the Loop Condition terminal. You should see the statistical results and visualized image after you click the stop button.

If you want to view the statistical results in real time, you can try to move the calculation part to the inside of the loop. Then it will be updated when you are acquiring signal from DAQ.