EEG-DIGITAL-ASM Vs Arduino Due

[ellecieffe]

Hi to all,

Is it possible to modify EEG-ANALOG-ASM in order to be like a shield and,so, to use Arduino Due (or a similar olimex product) like digital board instead of EEG-DIGITAL-ASM ?

Realated questions:

- I know that a biomedical instrument has need of an isolation circuit for the user. Can a shield be isolated from the digital board?

- Is the openEEG firmware portable on the micro of Arduino Due?

Many thanks

[LubOlimex]

Hey ellecieffe,

- Is it possible to modify EEG-ANALOG-ASM in order to be like a shield and,so, to use Arduino Due (or a similar olimex product) like digital board instead of EEG-DIGITAL-ASM ?

Generally, everything is possible.

You can use OLIMEX's OLIMEXINO-328 (or similar Arduino board) but you have to:
1) Switch it to 5V (to provide 5V to pin 1 of the analog)
2) You will have to recreate part of the digital schematic that goes to pin 2 - analog reference voltage part. This part might be seen here: http://i.imgur.com/uTTCPik.png. I will upload the schematics of the boards on their respective web pages in both Eagle and pdf formats by the end of the day for better readability.
3) You will have to use custom wires and connect the rest of the signals accordingly
4) You will need to write own software that manages to follow the OpenEEG p2 firmware: http://openeeg.sourceforge.net/doc/modeeg/firmware/modeeg-p2.c

Overall it can be done. We haven't done it so I can't guarantee a hundred percent.

- I know that a biomedical instrument has need of an isolation circuit for the user. Can a shield be isolated from the digital board?

I don't quite get this question.

- Is the openEEG firmware portable on the micro of Arduino Due?

Yes, it is but it will probably require some tweaking and a programmer.

Best regards,
Lub/OLIMEX

[ellecieffe]

Thank you for the reply

About the question of isolation circuitry I would to know if there is the possibility to use a opto-coupler (or something like this) in the analog shield, instead of in the digital shield (that have in general only a ESD circuit ). So I could use OLIMEXINO-328 (or Arduino) without modification, maintaining good safety condition for the user.

Sorry for the noob question, maybe I'm little confused

[LubOlimex]

Hey ellecieffe,

It is a good idea to use something like USB-ISO between the OLIMEXINO-328 and the computer (https://www.olimex.com/Products/Modules/Interface/USB-ISO/), adding any galvanic insulation is recommended. However note that OpenEEG is not a commercial product - it hasn't passed any official test nor licenses and is not recommended for professional environment. Something more - using it on others without their knowledge is strictly prohibited. Read the full disclaimer here: http://openeeg.sourceforge.net/doc/WARNING.html

Since I see you are preferring to work with Arduino, I feel obliged to recommend you SHIELD-EKG-EMG that has a ready library for Arduino. It is not as precise as the OpenEEG projects and isn't recommended for EEG capture but for EKG experiments is a very nice solution. Link to its page: https://www.olimex.com/Products/Duino/Shields/SHIELD-EKG-EMG/

Best regards,
Lub/OLIMEX

[ellecieffe]

It is a good idea to use something like USB-ISO between the OLIMEXINO-328 and the computer (https://www.olimex.com/Products/Modules/Interface/USB-ISO/), adding any galvanic insulation is recommended.

I did not know it. I'll keep that in mind for future use.

However note that OpenEEG is not a commercial product - it hasn't passed any official test nor licenses and is not recommended for professional environment. Something more - using it on others without their knowledge is strictly prohibited. Read the full disclaimer here: http://openeeg.sourceforge.net/doc/WARNING.html

Yes, I know the laws that govern the use of electromedical device, I know the disclaimer and understand the risks of the interaction between the human body and electricity.
I'm trying to achieve this only for research purposes.

Since I see you are preferring to work with Arduino, I feel obliged to recommend you SHIELD-EKG-EMG that has a ready library for Arduino. It is not as precise as the OpenEEG projects and isn't recommended for EEG capture but for EKG experiments is a very nice solution. Link to its page: https://www.olimex.com/Products/Duino/Shields/SHIELD-EKG-EMG/

In general I prefer to work with the KISS method 
Considering that I already have an Arduino (and also an olinuxino A13 wifi ) I thought of something compatible with it, which is also compatible with olimex  products, however.

You think it's easier use the libraries for EKG / EMG, properly modifying it , or make porting the firmware openEEG and send raw data ti the laptop? (I would use openVibe software such as neurofeedback)


Many, Many thanks

[LubOlimex]

Honestly, modifying the аnalog part of OpenEEG to work with Arduino would be much harder. It would require both hardware and software knowledge. The thing is that OpenEEG device wasn't meant to interface any other device, it was supposed to work alone in its original form.

On the other hand the shield should work with most Arduino boards by just plugging it over and copying the library in the respective library folder in Arduino IDE (check their article on library installation http://arduino.cc/en/Guide/Libraries).

Please check the device's page in software section: https://www.olimex.com/Products/Duino/Shields/SHIELD-EKG-EMG/. There are couple of projects in YouTube even: http://www.youtube.com/watch?v=15D6zbXlQ4c; http://www.youtube.com/watch?v=47Nis8ITqoo.

Best regards,
Lub/OLIMEX

[ellecieffe]

Ok, I've understood. I'll work around the EKG/EMG shield.  Thanks

Best Regards