LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Reading EMG signal with LabVIEW

 

hello everyone;

I am an engineering student working with USB-6008 and LabVIEW for the first time. I am working on a project that displays the signals received from the muscles with the EMG sensor graphically on the computer screen using USB-6008 and LabVIEW. I want to capture 6 emg signals for a while. The signals will be conditioned. I want to control data capture with a Start/Stop control. I would like to calculate and display the Average Integrated values for each of the six signals during the six impression display and experience it over that period of time. Only the Average Integrated EMG (millivolt intensity) is given to be able to record the contraction of a unit. For each trial we will have 6 muscles connected to the electrodes (6 analog input channels). Participants/subjects will complete two exercises; The exercise will be done in two repetitions. Each exercise will be completed at a steady pace, repetitions... I want to use the Start/Stop control to stay in control throughout this exercise. After many attempts, I failed. I may have made a mistake in the installation of the system or in the LabVIEW part. So, can anyone help me with system setups and LabVIEW part? I'll be glad if you help. I've left the pictures and links of the tools I use below.

EEEstudent_0-1691940184632.jpeg
 
EEEstudent_1-1691940193672.jpg

 

 

0 Kudos
Message 1 of 3
(1,257 Views)

Well, I've recorded EMGs before (usually with "home-made" patch electrodes, though I once stuck a pair of acupuncture needles into my arm and tested the EMG integrating amplifier I built with a 741 op-amp and a few other parts to do full-wave rectification and low-pass filtering).  This was before I "met" LabVIEW ...

 

You need to know a little bit about signal analysis, a little bit about muscle physiology (to understand what you want to extract from electrical signal you'll be recording with your surface electrodes), something about where to place the electrodes, the difference between "single-ended" and "bi-polar" recording (and what that says about how many and where you place the electrodes).

 

And then there's LabVIEW and DAQmx.  Some advice -- don't try to write the entire program all at once (even if you are "reasonably familiar" with LabVIEW).  Take a crucial "inside" step, like getting data from a single channel (is it "obvious" to you that this requires two electrodes?) and displaying it.  Of course, since you are using external "patch" electrodes, you could put a pair on yourself (where?).  Do you have an oscilloscope handy?  Might be handy to know (from a "known and trusted measuring instrument") something about the EMG signal, like its amplitude and approximate frequency range.  You may need to do some "signal conditioning" to get a signal suitable for the USB-6008.

 

Your first attempt should probably acquire data continuously from a single A/D channel, and display the output on a Waveform Chart.  Do you know enough LabVIEW (and DAQmx) to do this yourself?  [Without your attaching LabVIEW code that you've written, we can't tell how much LabVIEW help/training you need.]

 

Something to note -- many of the more-experienced LabVIEW developers (including myself) do not install the "latest version" every year.  For example, I'm primarily using LabVIEW 2019, so you should consider using "Save for Previous Version" if you want to post your code.  Please do not post "Pictures of Code" -- this leads to unhealthy rise in blood pressure in long-time Forum participants.

 

Bob Schor

0 Kudos
Message 2 of 3
(1,231 Views)

@Bob_Schor wrote:

Well, I've recorded EMGs before (usually with "home-made" patch electrodes, though I once stuck a pair of acupuncture needles into my arm and tested the EMG integrating amplifier I built with a 741 op-amp and a few other parts to do full-wave rectification and low-pass filtering).  This was before I "met" LabVIEW ...

 

You need to know a little bit about signal analysis, a little bit about muscle physiology (to understand what you want to extract from electrical signal you'll be recording with your surface electrodes), something about where to place the electrodes, the difference between "single-ended" and "bi-polar" recording (and what that says about how many and where you place the electrodes).

 

And then there's LabVIEW and DAQmx.  Some advice -- don't try to write the entire program all at once (even if you are "reasonably familiar" with LabVIEW).  Take a crucial "inside" step, like getting data from a single channel (is it "obvious" to you that this requires two electrodes?) and displaying it.  Of course, since you are using external "patch" electrodes, you could put a pair on yourself (where?).  Do you have an oscilloscope handy?  Might be handy to know (from a "known and trusted measuring instrument") something about the EMG signal, like its amplitude and approximate frequency range.  You may need to do some "signal conditioning" to get a signal suitable for the USB-6008.

 

Your first attempt should probably acquire data continuously from a single A/D channel, and display the output on a Waveform Chart.  Do you know enough LabVIEW (and DAQmx) to do this yourself?  [Without your attaching LabVIEW code that you've written, we can't tell how much LabVIEW help/training you need.]

 

Something to note -- many of the more-experienced LabVIEW developers (including myself) do not install the "latest version" every year.  For example, I'm primarily using LabVIEW 2019, so you should consider using "Save for Previous Version" if you want to post your code.  Please do not post "Pictures of Code" -- this leads to unhealthy rise in blood pressure in long-time Forum participants.

 

Bob Schor


Oawwww Bob,  just point him to the LabVIEW example Project Templates that install with DAQmx.  Then his code will look like the way experienced LabVIEW Developers start commonly implemented projects 🙄

 

Make sure you point out the helpful links in the select Project Template dialog that will get him straight to the details from NI.com and even point to Developer Walk-through videos of the Project Templates given by the NI developer team members!

 

I'm Thinking that the Acquire Analyze Display loops in the Finite Measurement and Logging (DAQmx) Project Template would do.

 

Now to physical Wiring.   I see three single electrodes Black White Red at Tip, Ring1, Ring2.  They will form 3 differential pairs.  Black to AI0,AI10(-AI2) White to AI1,AI8(-AI0) and Red to AI2,AI9(-AI1) or, simply Black-White, White-Red, Red-Black differential pairs.  The DAQmx Driver knows which physical connection to use when reading from differential AI Channel 0:7

 

As for the gizmo circuit board....your link gets me to a 404 error in... Turkish...I'm not sure what that is.  Hopefully, it is some sort of signal conditioning module.


"Should be" isn't "Is" -Jay
0 Kudos
Message 3 of 3
(1,197 Views)