To record bipolar EEG, you will need an EEG amplifier for each pair of electrodes that you want to calculate the potential difference between. It is important to note that you can also derive bipolar measurements from unipolar measurements. This is done in software. For example, if you are recording from sites A, B, C in unipolar you can then get the following bipolar measurements:
AB by calculating A-B
BC by calculating B-C
AC by calculating A-C
If you want to look at all possible pairs, you can calculate the combinations without repetition: n!/(r!(n-r)!) where n is the number of electrodes and r is 2.
For example, for a bipolar recording on 5 sites you would need 5!/(2!3!) = 10 EEG amplifiers. This assumes that you want to look at the potential difference between all possible combinations of electrode sites. This is the maximum number of EEG amplifiers that would be required.
Here is a reference for the number of EEG amplifiers required if you need to look at all electrode pair potential differences:
New series of unshielded 45 cm electrode leads with thin cable; suitable for facial EMG and other areas where lighter, shorter lead cables are required. Use for female Touchproof connectors to pinch clip connectors—connect electrodes to either a C-series amplifier or an MEC. The pinch connectors are light weight and the lead cable tinsel wire […]
The new issue of Psychophysiology has a study “Quantifying rapid changes in cardiovascular state with a moving ensemble average” using MEAP for preprocessing/analysis and BIOPAC hardware and software for data collection, display, and storage. The proof of concept study demonstrates a viable method for the adoption of ICG measures across the field of psychophysiology. MEAP (moving ensemble […]
BIOPAC provides software and hardware that allow for research teams to record and analyze respiration activity in physiological experimentation. Here are a few notable studies covering MRI, ECG, and Laser Doppler Flow measurement. fMRI & Thermal Perception: The neural mechanisms underlying thermal perception (how hot or cold we perceive the temperature to be) have not been fully […]