Building an EEG with a Digilent Analog Discovery 2

[Wdshaf0]

I am a chemistry professor at a small Liberal arts University. I have student who is wanting to go into med school to study the brain. For her senior research project, we thought to build an EEG with pieces we have on hand here at the University. We have a few Digilent analog Discovery 2 devices, some ADALP2000 Analog parts kits and older versions of Lab-view for Windows 7 and 98. I'm open to using the wave form software as well.

We've been doing some hunting, and we're afraid we are getting lost in the mix. I have some, but minimal knowledge of electronics and she has virtually none. I can use a meter reader, and know some basics between amps, voltage, and ohms. I've not found anything on this forum specifically and online, we have found some routes but not one where we have all the part on hand. What would be, or is there, a simple route for where we could build a simple EEG machine using these parts and pieces. A schematic or picture description anything so I have a direction would be wonderful.

Thank you

 

Will

[JColvin]

Hi @Wdshaf0,

I have moved your question to a more appropriate section of the Forum.

I don't think Digilent has anything specifically on making an EEG, but I know there is a linked community project on the Analog Discovery 2 Resource Center that looks like it makes an EEG of some kind (I don't know how extensive it is) under the Community Projects: https://digilent.com/reference/test-and-measurement/analog-discovery-2/start#highlighted_community_projects.

Thanks,
JColvin

[zygot]

You've probably got the parts for capturing data and doing analysis of a common range of signals, but I doubt that you have the parts required for the front-end analog conditioning required for capturing usable Biopotential signals. I'm not making any assumptions about the capabilities of your student, it's just that designing circuits for acquiring such low level signals requires some special knowledge. There are a few ICs for such a project like the ADS1299 or MAX30001 that might be available in a kit form and **might** be suitable. At least you can go to Analog Devices and Texas Instruments and do a search on what's available ( ADI now owns Maxim IC ).

I think that I've seen an EEG product on Crown Supply at one time.

Scrounging around the lab for stuff to do EEG signal acquisition or build a DYI electron microscope seems to be a bit much even for a brilliant mind that's a very quick study. Designing a safe usable EEG analog front-end from scratch would be quite a challenge even with an unlimited parts stock available for even a Biomedical Engineer I imagine.

A place to start is by finding a good engineering text on the subject if for nothing else than getting a sense of what you are getting into. For ECG applications there are some good non-invasive ways to acquire biometric signals but I doubt that the same is true for EEG. I'm no expert on this by the way though I do have some medical device design experience.

[Wdshaf0]

Thank you both for all your help.

I figured it would be a tough route to go, but I thought it would be worth asking someone more skilled than I in this field. Most of my work is in materials and catalysis, and so I have some knowledge here, I'm by no means an expert. However, I do like getting myself into messes as that is what makes the research run.

It seems to me, that to make one would require building a micro-ampere meter to monitor the electrode signals between a ground, and the active. Then sending that signal to some sort or readout (i.e. the computer). Is that too simple?

We did find this - but did not have the exact amp pieces mentioned here. The kit has a few amps, but still not 100% sure yet.

Thank you!

Will

 

 

[zygot]

Yeah, I remember a time a long time ago when bio-feedback was a new and hot idea for detecting alpha waves and such; and there were a number of DYI ideas floated about.

Here's what I'm thinking. If I were just playing around and experimenting I'd consider a lot of options. If I were trying to achieve a particular goal, in a specific time frame, and my future depended on it, I'd be a lot more choosy about options. Building something, and building something that's usable ( whatever that means ) are rarely the same thing. Of course, there are a lot of people who are a LOT smarter than I am so I might be overly conservative.

My impression is that capturing useful EEG waveforms is a lot more complicated than converting microvolt potentials into digital data. I'm thinking sub-cutaneous probes and current driven pickup. I could be wrong though. Edited April 29, 2022 by zygot