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Problems with SynAmp Neuroscan amplifier during calibration

Posted: 19 Aug 2010, 06:56
by paolobernardis
After installing BCI2000 and configuring the StimulusPresentation task, we are facing a problem of calibration when trying to set up the Neuroscan Scan 4.3.1 software. Specifically, we launch the acquire tool and when we calibrate the amplifier we record a 5 microvolt signal instead of 1 microvolt.
Is it possibile to be a result of BCI2000 installation? Can this problem be fixed?

Thanks in advance,
Paolo :shock: :roll:

Neuroscan

Posted: 19 Aug 2010, 10:31
by gschalk
Hi,

Are you using the neurogetparams tool to get calibration values from the amplifier, and then loading those into BCI2000?

How do you assess signal amplitudes? Online or offline with Matlab?

Gerv

Re: Neuroscan

Posted: 19 Aug 2010, 10:58
by paolobernardis
gschalk wrote:Hi,

Are you using the neurogetparams tool to get calibration values from the amplifier, and then loading those into BCI2000?

How do you assess signal amplitudes? Online or offline with Matlab?

Gerv
Hi Gerv,

thank you for the help.
The problem happen when I try to calibrate the amplifier using the Scan 4.3.1 software, before to run BCI2000. The Acquire module shows a 5microV value instead of the correct 1 microV, which is the default value sent into the circuit by the system to calibrate the electrodes.

My idea was to start with the Scan software, calibrate, prepare a subject with the ElectroCap, connect the Cap to the amplifier, and then put the amplifier in server mode, and last run the BCI2000. Is that sequence right?

thanks,

p.

Neuroscan

Posted: 20 Aug 2010, 07:14
by gschalk
Hi,

If you see incorrect values in Acquire, isn't this a Neuroscan problem? If there is a constant factor that can correct the amplitude values, you can simply manually change the SourceChGain parameter within BCI2000 (see the wiki on doc.bci2000.org for more information on that parameter) to correct it.

Gerv

Re: Neuroscan

Posted: 20 Aug 2010, 07:32
by paolobernardis
Hi,
gschalk wrote:If you see incorrect values in Acquire, isn't this a Neuroscan problem?
well, that's correct. but since the problem with the calibration appeared only after the installation of BCI2000, I was trying to figure out whether one (improbable) cause could be the BCI2000. Probably not, because I removed BCI2000 and reinstalled Neuroscan software, but the calibration problem persist.
gschalk wrote: If there is a constant factor that can correct the amplitude values, you can simply manually change the SourceChGain parameter within BCI2000 (see the wiki on doc.bci2000.org for more information on that parameter) to correct it.
thanks, i'll try this solution.

p.