Cyton wiring for Brain-Trainer with BioEra [resolved]
Hi Everyone,
I am just starting experimenting with neurofeedback using brain-trainer with bioera.
Is there anyone who successfully used Cyton for both assessment and then training ?
It seems Peter does not have too much experience with OpenBci boards and I cant find any info
how to wire the SRB and BIAS electrodes for monopolar and bipolar montages and/or for the 4 channel assessment.
Also, I would be very much interested in any feedback related any aspects of BT4BE with OpenBci board.
Any info would be greatly appreciated.
Regards
Peter
Comments
Peter, hi.
SRB2 (pin closest to board) is your default "Reference" electrode. Bias pin is the same as "Ground" in other amplifiers. The channel pins (IN1N through IN8N) are also the pins closest to the board, and use the common Reference.
Have you looked over the Cyton tutorial?
https://docs.openbci.com/GettingStarted/Boards/CytonGS/
https://docs.openbci.com/GettingStarted/Biosensing-Setups/EEGSetup/
I have used Brain-Trainer in the past with the previous Bioexplorer package (and other amplifiers). I also use BioEra with my own designs and Cyton. Have not used Pete's new BioEra Brain-Trainer setup, but info above should allow you to adapt his instructions.
Regards, William
Thank you William,
Thank you,
I assumed this was more complicated as Peter (when asked via email directly) mentioned there were some problems with the setup.
Regards
Peter
Can you be more specific? Did you go through the tutorial pages mentioned above? Cyton is just another EEG amplifier and all of these have connections for each channel, ground, and reference. Have you applied the FTDI "Windows fix" that helps the FTDI serial port driver operate more smoothly?
https://docs.openbci.com/Troubleshooting/FTDI_Fix_Windows/
Yep, knew the docs.
My question to Peter was rather related to the fact that their amp of choice is the q-wiz which seems to have
multiple ref electrodes.
From their manual:
I understand that the output of the EEG very much depends on the montage (reference model) used,
and their software needs certain type of montage
Many neurofeedback setups, use for reference, what are called "linked ears". In other words a small touchproof jumper device, such as,
https://www.google.com/search?q=touchproof+jumper+wire
Is used to electrically connect BOTH ear lobes, to the single reference pin on the amplifier. This is a very common setup for many QEEG / assessment sessions. Another commonly used practice is then to place the Ground connection, somewhere on the 'midline' of the client. (Any of the 10-20 'Xz' positions.)
The other common setup, is to place Reference on one earlobe, and Ground on the other. This is what is shown in the OpenBCI EEG tutorials.
Thanks William,
I will go through their q-wiz manual again to get my head around their setup.
Of course you realize that the 4-channel Q-Wiz is designed to mate with the DB-25 connector found on Electro-cap's (and others using the same connector). Thus Q-Wiz can (with the press of a button on the unit), cycle through different 4-channel scalp positions. Which eases the work doing 19 or 20 channel assessments with a cap.
Simpler amps such as Cyton don't have this switching ability, so changing scalp locations requires moving wires.
yep, I got that.
I was just puzzled with this "multi reference" note in the manual.
I have not used Q-Wiz, but have used other Pocket-Neurobics equipment. Since use of "linked-ears" is found frequently in neurofeedback, they just built this into the amp, rather than requiring separate jumpers. If you look at the front panel:
https://www.khemcorp.com/wp-content/uploads/2015/09/img_6040.jpg
You can see the pattern of touchproof connectors. The plus channels are wrapped around the outsides: 1+, 2+, 3+, 4+. Then in the middle center are the two minus pins of channels 1 and 2: 1- and 2-. In the center between them is a button and LED light. When pressed once this light will turn on and 'link' the two ear lobe references. Pressed again, the light will turn off and the references are separate.
I think the 1+ and 3+ channels share the 1- reference. The 2+ and 4+ channels share the 2- reference. When linked, all channels are operating with the same "linked-ears" reference system.
That's exactly what I meant.
But this also means that each of the 2 pairs of channels can have independent referencs.
Not sure if this is ever used in any of the Peter's designs though.
I sincerely doubt it. You can ask him. If needed, Cyton can be setup for this, but I know of no past Forum threads asking for this.
Yep, will do.
I will post Peter's response here after I get it.
Regarding such jumpers, used for linked ears. You can actually make your own Y-jumper, that attaches directly to the Cyton SRB2 pin. And thus allows the single SRB2 reference pin to connect to TWO touchproof ear electrodes. You purchase a pack of male female jumper cables:
https://www.adafruit.com/product/826
Separate out two of these wires from the ribbon. They just pull off the ribbon. Cut both at the halfway point. Use a wire stripper tool to 'strip' about 1/4" insulation from the ends of the wires. Now twist together the wire ends of one female with two males. Use some type of tape to insulate the wire connection. Or heat-shrink tubing if you have that available.
Now plug the female onto the SRB2 pin. And two of your touchproof adapters (for the ear clips) attach to the male Y-cable ends. You now have two "linked ears" reference electrodes.