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Re:RaspberryPi for measuring bio signals (open source) by smr88 on Wednesday August 10, 2022 @11:56AM (#32414139)
Ah the Brain-Computer-Interface. While in university I worked on such a thing. The EEG acquisition hardware was from g.tec medical engineering with an interface to Matlab. I trained a Neural Network (it was the year 2010) to classify steady state visually evoked potentials.
Re:RaspberryPi for measuring bio signals (open source) by vorpalhex on Wednesday August 10, 2022 @01:29PM (#32415619)
Did the NN do a pretty good job with signal cleanup and consistency?
Re:RaspberryPi for measuring bio signals (open source) by smr88 on Wednesday August 10, 2022 @03:29PM (#32417237)
Maybe I have to elaborate a bit here. Neural Network sounds fancier than it really is. The steady state visually evoked potentials work as I recall in the way that when a person stares at a light source which blinks in a particular frequency then one can measure an EEG signal over the visual cortex which has the same frequency and multiple of it, as the light source. For example if a person concentrates on a blinking LED with 4Hz then a signal with dominant 4Hz and 8Hz, 12Hz and so on can be measured over the visual cortex. I think in this explanation are some details missing ;-) We used LED sources with different frequencies which represented different actions like left, right, up, down etc. The Neural Network was trained with the frequency spectrum as input and not with the raw EEG signal. However I think the correct and easier solution was to use a filter bank (comb filter) to determine the frequency of the currently measured EEG signal. But back then I read the first time about Perceptrons, XOR problem and Neural Networks. It was cool and I wanted to try it out. The challenging part back then 2010 was that there was no TensorFlow or Pytorch. I was equipped with Matlab, the Signal Processing Toolbox and my dangerous superficial knowledge about Neural Networks. I implemented backpropagation and gradient descent myself for fun and the output was a matrix which represented the weights of the Neural Network. The "inference engine" was a matrix multiplication. The matrix with the weights multiplied with an input vector and as the activation function I used tanh(). Surprisingly the classification worked very well and it was fun to implement all that stuff. This all sounds like grampa talking about WW2 again :-)
Re:RaspberryPi for measuring bio signals (open source) by ron_87 on Thursday August 11, 2022 @04:00AM (#32422813)
sounds really, very cool
Re:RaspberryPi for measuring bio signals (open source) by smr88 on Thursday August 11, 2022 @11:59AM (#32427711)
Thanks :-)
Re:RaspberryPi for measuring bio signals (open source) by Marat_Tokyo on Wednesday August 10, 2022 @10:39AM (#32412746)
RaspberryPi for measure bio signals (open-source). Now, all data in GitHub page https://github.com/HackerBCI/EEGwithRaspberryPI Also all signal processing in EEG will be here https://github.com/HackerBCI/EEG-BCI-signal-processing Please, follow and contribute and any feedback are very welcome #pieeg #RaspberryPi #EEG
Re:RaspberryPi for measuring bio signals (open source) by destitude on Wednesday August 10, 2022 @12:19PM (#32414487)
Where can anyone even get a Raspberry Pi now-a-days? Nothing that I see has been in stock for at least 6 months now except for the 400 with keyboard.
Re:RaspberryPi for measuring bio signals (open source) by vorpalhex on Wednesday August 10, 2022 @01:30PM (#32415635)
Re:RaspberryPi for measuring bio signals (open source) by ron_87 on Thursday August 11, 2022 @04:00AM (#32422816)
raspberryPi3
Re:RaspberryPi for measuring bio signals (open source) by sxp on Wednesday August 10, 2022 @12:42PM (#32414882)
Are there any price estimates? Even an order-of-magnitude estimate would be nice. https://www.hackerbci.com/shop and https://www.crowdsupply.com/hackerbci/pieeg don't tell me if the target is $100 or $10,000
Re:RaspberryPi for measuring bio signals (open source) by flaviut on Wednesday August 10, 2022 @01:09PM (#32415336)
Looks like 4 $10 voltage regulators and 1 $70 ADC. The board seems simple and cheap enough.

Hope they stocked up, because the chip shortage is hitting their chosen parts hard.

Re:RaspberryPi for measuring bio signals (open source) by ron_87 on Thursday August 11, 2022 @04:02AM (#32422825)
it seems that the situation in the chip market is stabilizing