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Author Topic: EEG- SMT EEG Signal Acquisition  (Read 7195 times)

harithota20

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EEG- SMT EEG Signal Acquisition
« on: December 31, 2013, 10:44:21 AM »
Hi,
  I bought EEG SMT recently and started testing it.
I tested the device with single channel with active electrodes and one passive electrode for DRL.
I used brainbay software and i used example program for acquiring single channel data.
i had put it in ModularEEG P2 mode and acquired the signal at FP2 and F8 positions and holding passive electrode in hand. Surprisingly i got ECG wave forms instead of EEG as shown below.
The first one is without filtering and the second one is with band pass filtering between 0.5 to 45Hz.


After that i put that DRL electrode back side of ear A1 position i got below signals ( same configuration as above)
 
 

I used Electric Guru software also i got the signal as shown below.
 

Now, my doubt is that how to identify correct EEG signal?
What are all the things i need to check whether my signal is correct EEG signal or not?
To get a good single channel EEG signal which configuration i need to select in brainbay?
« Last Edit: December 31, 2013, 10:49:36 AM by harithota20 »

LubOlimex

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Re: EEG- SMT EEG Signal Acquisition
« Reply #1 on: January 10, 2014, 08:54:33 AM »
Hey there,

The easiest way to test is to use Electric Guru or Brain Bay. Please place the electrodes of one channel a bit over both temples and then hold the DRL firmly in hand. Then after you start the monitoring roll your eyes right and left and check the readings. They should look as below:

http://i.imgur.com/1hh6Zy8.png
http://i.imgur.com/9SJgaCp.png

Best regards,
Lub/OLIMEX
Technical support and documentation manager at Olimex

harithota20

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Re: EEG- SMT EEG Signal Acquisition
« Reply #2 on: January 21, 2014, 10:43:29 AM »
Hi Lube,
    Please let me know the exact placement of single channel +ve and -ve electrodes according to below picture.
i am still in dilemma at the right placement of electrodes on forehead.
     
   
     
      If you are having any picture related to it, please upload.

BMcFrizzle

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Re: EEG- SMT EEG Signal Acquisition
« Reply #3 on: March 20, 2014, 04:58:37 AM »
+ve: Fp1, -ve: A1

Then do as Lub has described -- roll your eyes or blink and you should see something. You might also want to connect the electrodes to channel 2 and just connect them together (short them) -- this is recommended in the user guide/manual.

Btw, how strange that you got ECG signals... but also kind of cool.

harithota20

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Re: EEG- SMT EEG Signal Acquisition
« Reply #4 on: March 22, 2014, 06:03:04 AM »
Hi Friz,
  Thank you for your suggestion.
If +ve Fp1 and -ve A1, How about DRL? I have to hold it in hand firmly?
I will try this..

BMcFrizzle

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Re: EEG- SMT EEG Signal Acquisition
« Reply #5 on: March 24, 2014, 07:58:32 AM »
Yes, hold the DRL in your hand. Let us know that you are getting the intended results.