How to apply Root Mean Square Processing on an EMG Signal stored as a LVM file?

[ArvinB]

Greetings,

I've been working on my wireless EMG project, implemented using and Arduino(for A/D conversion) and Bluetooth technology. I have successfully received the data on the computer and save it to an LVM file for processing. I've attached a sample data from one of my tests. Now, how would I perform processing on it? I would first want to rectify the signal but I know I can do that by using the absolute value function.

More importantly, after the rectification, how would I perform the Root Mean Square processing on the rectified signal? I've also attached a PDF file which talks about EMG signals in general, the part about RMS is on page 27. I am not familiar with using arrays in LabView if that will be used here, and I am using Labview2010.

A sample file on how to implement the RMS processing would be most helpful. Thank you.

[johnsold]

Look in the Mathematics >> Probability & Statistics palette for Mean and RMS VIs.  You do not need to rectify before doing RMS.  The squaring part of the RMS caclulation has the same effect.

Your data has a large DC offset. You may want to subtract the mean before doing your other processing.

I sometimes think EMG community is lost in the 1950s.  Much of the description of the signal processing is based on doing it all in analog circuitry.

Lynn

[Ramon Campos]

Hi ArvinB..

I try to do some rms on your signal, but it's still saved without time information..... (first column if full of 0)

anyway, to implement some rms:

signal processing -> wfm measure -> avg DC-RMS vi......

or just on the biomedical startup kit source code -> process & analysis ->  EMG -> emg - Average RMS vi

Try that.

[ZJ.Gu]

Definitely agree with Ramon

[ArvinB]

Hello Ramon,

Sorry it took a while. I've attaced a signal with some time information here. Can you show me how to use the avg DC-RMS vi? I've also attached a VI that I use to open and do some processing on the file.

Thank you

[Ramon Campos]

hi Arvin....

i did some implementation on your code.....

you could change the "rms window"... it's usually below 500ms

good luck.