Search found 8 matches

by max
Thu Jun 04, 2009 8:23 am
Forum: BioSemi Hardware
Topic: high correletaion of data in salt water?
Replies: 2
Views: 6839

Dear Coen, thanks for your fast reply. Yes, I did use the unreferenced signal. I thought, that if I reference the data, I would increase the correlation, as I add (or better said substract) a common component to the data. Of course in the raw data there is the CMS/DRL as the common component. But I ...
by max
Wed May 27, 2009 2:23 pm
Forum: BioSemi Hardware
Topic: high correletaion of data in salt water?
Replies: 2
Views: 6839

high correletaion of data in salt water?

Hi to all, A few weeks ago I decided to test the functionality of my electrodes, by doing the recomended measuring in salty water. The data looked fine and everything seemed ok. Then I noticed, that there is a higher correleation between the data for higher sample frequencies. e.g.: mean of correlat...
by max
Fri Feb 27, 2009 3:39 pm
Forum: BioSemi Software (ActiView executable)
Topic: Additional Trigger Question
Replies: 6
Views: 13295

Thanks for these answers
by max
Fri Feb 20, 2009 4:10 pm
Forum: BioSemi Software (ActiView executable)
Topic: Additional Trigger Question
Replies: 6
Views: 13295

Dear Coen I did some test measurements do learn more about the triggers, and I noticed the following: First of all it is possible to send external triggers and function key triggers simultaneously without soldering. I always tried the function keys without the trigger cable connected - and then it w...
by max
Thu Feb 19, 2009 11:51 am
Forum: BioSemi Software (ActiView executable)
Topic: Additional Trigger Question
Replies: 6
Views: 13295

How to send external triggers+ F1-F8 triggers simultaneously

Dear Coen, I'm sorry, but after reading lots of forum entrys and the relevant webpages on your website I still do not understand how it is realisable to send external triggers and function key triggers simultaneously. [quote="Coen"]Make sure that the trigger inputs 9-16 are pulled low at the trigger...
by max
Fri Nov 21, 2008 1:10 pm
Forum: BioSemi Hardware
Topic: hardware bandwidth limit
Replies: 1
Views: 6775

hardware bandwidth limit

Hi Coen is it possible to explain how you computed the filter graph shown on the webpage http://www.biosemi.com/faq/adjust_filter.htm (of course not in detail) What unfilterd Powerspectrum-behavior of the EEG-data did you assume? 1/f-noise? I'm just asking beause I don't recieve the same filter beha...
by max
Tue Jul 22, 2008 3:04 pm
Forum: BioSemi Hardware
Topic: Differential Amplification
Replies: 6
Views: 24841

Hi Coen. Thanks a lot for the fast reply and your help. As I just changed the sample rate for my measurements (measured the participant for about 1 minute, then switched off the A/D box, changed the sample rate, restarted and measured again with the new sample rate at exactly the same conditions) it...
by max
Sun Jul 20, 2008 10:41 am
Forum: BioSemi Hardware
Topic: Differential Amplification
Replies: 6
Views: 24841

[quote="Coen"]...Consequently, the CM voltage is reduced by the open-loop gain of the DRL circuit. ... the open-loop gain of the DRL driver decreases with frequency[/quote] Dear Coen, can I understand this in the way, that for high sample rates the interferences aren't reduced as much as for low sam...