My SSVEP BCI, 16 LED matrix
nekrodezynfekator
Poznan, Poland
Hi,
I'm working on my phd thesis. I designed and built BCI system using 8-channel OpenBCI.
I'm using my own photostimulator with RGB diode, Arduino UNO and board with 4xTLC5940. My BCI can recognize 8 different stimuli with accuracy >90% (it is work on that). In near future i want to extend the number of stimuli to 16 or more.
This is my control panel written in C#:
I will try to publish my papier in which I describe in details my BCI, but if u have any questions I will anwser here.
Comments
What kind of behaviors or outputs are you controlling with your SSVEP?
So you have 8 distinct flash patterns that can be recognized, with combinations of flash rate and matrix patterns? What would be some examples?
Curious about the ribbon cables, that's lots of wires, about 20 per cable and it looks like 4 ribbons.
The graph shown on the bottom photo, what do the bars represent, is this an FFT? What are the axes?
Looks like you are mainly using green or bluegreen for colors.
Thanks for that paper reference.
In your bar graph above, the top graph it seems obvious which choice is being made (16hz?) But in the bottom bar graph, it's not clear which frequency 'wins'. Why does it show two bar graphs at once. It may help us visualize how this works if you eventually post a Youtube of the array in action with some narration.
Best regards,
Marcin, can you clarify why you chose to use the sine wave intensity modulation?
Marcin, let us know the details...
Incidentally, a similar sine modulated intensity is used in some light therapy applications, to make the effect less harsh.
https://www.google.com/search?q="High-speed+spelling+with+a+noninvasive+brain–computer+interface"
http://english.cas.cn/newsroom/research_news/201511/t20151102_155042.shtml
For those who are not completely "locked in", in other words, have some muscles they can control -- it seems to me that the speller could be setup such that a voluntary muscle contraction could be used to trigger each letter. The user would look at the key, then contract. Then the SSVEP would commence to recognize that letter. Pretty simple and similar to the way we use fingers on keyboards. (Hunt and peck typers.)
Even in locked in cases, I think eye-blink could be used.
@qwer1304 wrote:
"What's your EEG montage (electrode locations, reference, ground, re-reference)?"
He was just asking if you had performed any re-referencing after the EEG was collected from your original reference. It's an optional step and not needed in your case since you already have found an optimal reference location for your SSVEP protocol. I assume after trying a number of reference locations.
Re-referencing is not associated with a 'pin' or amplifier channel. It's a software operation performed on the original data collected.
http://sccn.ucsd.edu/wiki/Chapter_04:_Preprocessing_Tools#Re-referencing_the_data
William
I faced to this article :"Fully Online Multicommand Brain-Computer Interface with
Visual Neurofeedback Using SSVEP Paradigm"
but i cant find any codes for it.
can somebody help me?
I want to know how can we make flickering speller to be presented on monitor screen?
Any help, suggestions or demo codes will be appreciated.
Thanks
http://openbci.com/forum/index.php?p=/search&Search=ssvep
http://eeghacker.blogspot.com/2014/06/controlling-hex-bug-with-my-brain-waves.html
http://about.bci-lab.info/demos
In addition to VEP demos, they include some BCIs based on auditory or tactile stimulation.
One of their latest cVEP projects is nominated in the 2016 BCI-Awards,
http://www.bci-award.com/