DAQ for processing EEG signal from 1-2 channels

[bsrb111]

Hello,

I am a phd student looking to create a setup for my lab to record local field potential (intracranial EEG signal) from mice to detect electrographic seizures. We only need to record from at most 1-2 electrodes as this will be done in tandem with 2-photon imaging and so we cannot use many electrodes. Also, we only need to record and analyze the LFP signal (NOT single unit activity or anything smaller than oscillatory activity) in order to demarcate seizure periods from the EEG. Therefore, we need to sample at around 1kHz or more from 1-2 channels. We already have a preamplifier and a headstage from CWE for this, but I am wondering which DAQ device will be the cheapest/effective solution for this? Would one of the USB DAQs (eg. USB-6001 from NI) be sufficient?

Thank you very much

[santo_13]

To select a DAQ for Analog Voltage capture, the following are needed,

• Number of channels - you mentioned 2
• Sampling rate - you mentioned 1kHz or better
• Resolution - ? number of bits
• Signal voltage level - ?

[bsrb111]

I think 14 bit resolution might be sufficient for this case since we are looking at relatively large amplitude deflections caused by epileptic activity in the mouse brain, and the voltage level of the signal in this case would be a few microvolts to few millivolts (but erring on the side of microvolts). For the USB DAQs, is the sampling rate listed the numbers of samples that each channel individually can sample at or is it the total sampling rate if all the channels were to be used at once?

[santo_13]

Typically, DAQ have a 10V range, and accuracy of measurements are already in the mV range. In this case your actual signal will be buried in the noise and errors.

You need an external precision amplifier to convert your signals into proper voltage range of the DAQ to properly maximize the accuracy range.

Are you interested in the frequency content of the signal or the absolute value of the voltage measurement?

I guess you might need DSA series of card with wide dynamic range and thereby measure signals in uV range as well.

[bsrb111]

We actually already have an amplifier that should have sufficient gain to amplify it to the V range for the DAQ. Sorry I misunderstood, I thought we were talking about the raw signal previously. I think in general though, the absolute value of the voltage is our main priority but the frequency content is a close second