sequential (bipolar) montage wiring setup

Comments

• wjcroft Mount Shasta, CA

  October 2016

  Pat, hi.
  
  1. if you just want everything referenced to Cz, put Cz on SRB2 and use the same default setup as the tutorial.
  
  2. You will need to make some Y-cables. And use the CHAN SET tab to disconnect the channels from SRB, as in the ECG, EMG part of the tutorial.
  
  Your Y cables can be made from short jumper cables such as,
  
  https://www.adafruit.com/products/1951
  https://www.adafruit.com/products/1956
  
  You will be cutting these in half, striping the ends about 1/2 inch, and making the Y's. Each Y consists of two females and one male. Twist all 3 wires together (possibly soldering for best connection), then use shrink wrap or tape to insulate the bare wire ends.
  
  An example wiring setup might look like:
  
  Fp1 - IN1N
  F3 - IN1P using Y to bridge IN1P and IN2N and male going to F3 electrode
  C3 - IN2P (similar idea with Y to IN3N)
  P3 - IN3P (with Y to IN4N)
  etc.
  
  William
  
• wjcroft Mount Shasta, CA

  October 2016

  I might have misunderstood your points 1 and 2. You can't have both together. You can either have a referential montage with all electrodes referenced to one other (on SRB2). Or the sequential montage, with NO common reference.
  
  EEG inputs are always differential with + and - pairs. With the default referential setup SRB2 is the common + bus. The IN*N pins are the electrodes.
  
  
• wjcroft Mount Shasta, CA

  October 2016

  One other possibility is to re-reference mathematically. This can be done in some circumstances such as going from referential montage to average. EEGLAB can do that one. But I don't think EEGLAB can handle sequential montage. And I'm not sure it can actually be done mathematically since sequential montage is doing unique site to site measurements. All that independently measured information would be lost if one tried to derive a sequential from referential, by math operations alone.
  
  Some medical fields demand the sequential montage, such as,
  
  https://www.google.com/search?q=sequential+montage+epilepsy
  
  
• wjcroft Mount Shasta, CA

  October 2016

  I ran across this re-referencing tool in ERPLAB. It looks like it could synthesize a (mathematics derived) sequential montage from a referential. Given that you enter all the relevant formulas.
  
  http://erpinfo.org/erplab/erplab-documentation/tutorial_4/Channel_Operations.html
  
  I would not know if this kind of derived montage would be acceptable in clinical settings that require greatest accuracy, for example.