It's not that critical which is used, as long as it is AC. You cannot use DC for skin impedance because that interface / electrolyte would polarize over time and not give accurate reading.

It's not that critical which is used, as long as it is AC. You cannot use DC for skin impedance because that interface / electrolyte would polarize over time and not give accurate reading. On Cyton a

Still can not make sense of the raw data. I use gold-plated electrodes for FP1 and FP2, and Ag-AgCl for FP7 and FP8. This combination gave me the lowest impedance:

Here is some background on how current injection can be used to measure impedance, on the ADS1299 (Cyton) chip.

I was looking at the schematics of the Ganglion board and am a little bit confused about the impedance measurement part. From what I understand, impedance measurement is used to check the impedance of

There are TWO types of impedance measurements of importance with EEG. The primary one is the SKIN IMPEDANCE, which reflects the quality of the connection between the electrode / paste / gel / and skin

I would like to ask, what is the impedance of OPENBCI when measuring EEG?

pressure on the skin and slightly reduce impedance. But take care not to become so tight as to be painful.

The amplifier INPUT impedance of the Ganglion differs from that of the Cyton. So that means Ganglion is more sensitive to skin impedance than Cyton. And the dry electrode skin contact accentuates this

with Ten20 and as it is seen by the video, the impedance is good. The exact same connection has been used prior and after with the OpenBCI Cyton, and it works perfectly. I remember that Ganglion used

One way to proceed would be to load the GUI into the Processing IDE, then add some printout statements (to the Console Log screen) that track the impedance calculation through the various steps. Then

I am a beginner working with EEG devices, and I have recently started exploring their functionalities. My current goal is to use Python to measure the impedance (N status) of individual channels from

However, if any of the electrodes that add to the bias generation (specified with the BIAS_SENSN register) lose contact with the patient, wild oscillations start up in the bias electrode and all other

.150 volts is 150 millivolts or 150,000 microvolts. That is a substantial DC offset. The phrase "...when these two metals come into contact..." is not quite the case with EEG. However you do

A second question: I am struggling to hold a good signal with the openbci Ag/AgCl snap electrodes. In the openbci GUI, they show a low impedance, always in the green, but then the time series will sho

with several people, maintained acceptable impedance levels, and configured 8 channels for SSVEP detection—yet still, no results. Using only the OpenBCI GUI and its frequency domain tool (FFT), we co

'Packet loss' is a separate issue than high impedance. Try relocating to other lab rooms that have less electrical equipment nearby. Such as extension cords, power supplies, LED lighting, wireless gea

EEG noise rejection is directly related to skin impedance. The higher the skin impedance, the worse the noise characteristics. Have you measured your impedances?

sorts of assumptions including electrode/patient impedance. If you enable all 32 BIAS * N/P of Cyton and Daisy, then given Vc in the input, the output will be -144*Vc... to drive pretty much the same

I recently started measuring EMG, EKG, and EEG signals with the Ganglion Board, but the problem is that I’m not getting a clean signal—it’s full of noise. Even though I measured the impedance, and it’