Search found 41 matches

by aloplop
16 Feb 2009, 05:36
Forum: BCI Systems - User Applications
Topic: Buffer Conditions for fixed Targets
Replies: 13
Views: 5058

Hi again, I updated the BCI2000 software to the latest version (revision 2280). I used the conditions I suggested in the last posts but changing the FeedbackDuration to 4 seconds, MaxFeedbackDuration = 8s and BufferLength = 12 seconds in the normalizer. I made some tests and the online operation was...
by aloplop
06 Feb 2009, 09:55
Forum: BCI Systems - User Applications
Topic: Buffer Conditions for fixed Targets
Replies: 13
Views: 5058

Hi,

maybe in the next week I´ll try the new version of the normalizer.

Thanks for all your interest.

Alvaro.
by aloplop
06 Feb 2009, 07:24
Forum: BCI Systems - User Applications
Topic: Buffer Conditions for fixed Targets
Replies: 13
Views: 5058

Gerv, the unique thing that changes from the Cursor Task application is that the targets are fixed in the X axis: Application:Targets:CursorFeedbackTask matrix Targets= 2 { pos%20x pos%20y pos%20z width%20x width%20y width%20z } 95 50 50 10 100 8 5 50 50 10 100 8 // target positions and widths in pe...
by aloplop
06 Feb 2009, 07:05
Forum: BCI Systems - User Applications
Topic: Buffer Conditions for fixed Targets
Replies: 13
Views: 5058

Gerwin, for the Update Trigger I had: Filtering:Normalizer string UpdateTrigger= (Feedback==0) // expression to trigger offset/gain update when changing from 0 (use empty string About the duration, they last 10 seconds at max: - FeedbackDuration: 5s - MaxFeedbackDuration: 10s - BufferLength in the N...
by aloplop
06 Feb 2009, 05:20
Forum: BCI Systems - User Applications
Topic: Buffer Conditions for fixed Targets
Replies: 13
Views: 5058

Results

Hi again, Finally, I performed some sessions with the fixed targets in the application I developed to control a Wifibot and a video Camera. Previously, I had made some tests in order to adjust the parameter FeedbackDuration in CursorTask, using for the MaxFeedbackDuration parameter the double of Fee...
by aloplop
22 Jan 2009, 04:34
Forum: BCI Systems - User Applications
Topic: Buffer Conditions for fixed Targets
Replies: 13
Views: 5058

Hi,

Gerwin, your response is very clarifying, so thank you very much once again.

Regards,

Alvaro.
by aloplop
21 Jan 2009, 04:18
Forum: BCI Systems - User Applications
Topic: Buffer Conditions for fixed Targets
Replies: 13
Views: 5058

Hi, Thanks for your response, but those conditions are the same than in the Cursor Task, where the target appears randomly. In the one I want to use, the cursor is centered in the screen and moves along the X direction to the target on the left or the right. The next week I´ll try the same condition...
by aloplop
16 Jan 2009, 04:07
Forum: BCI Systems - User Applications
Topic: Buffer Conditions for fixed Targets
Replies: 13
Views: 5058

Buffer Conditions for fixed Targets

Hi, In the application I want to use (the modification of the Cursor Task Feedback ), two targets should be positioned on the edges of the screen, but they should be fixed so there´s no random appearance. In my case, the cursor moves just in the X direction, so the Buffer conditions for the Normaliz...
by aloplop
02 Jan 2009, 15:44
Forum: BCI Systems - User Applications
Topic: CAR in Spatial Filtering
Replies: 3
Views: 2361

Hi, thanks Gerv for your quick response in these special days. I´ll do some tests using the Sparse Matrix when I return back from holidays. I forgot to say that using that configuration and selecting CAR filtering in the Offline Analysis Tool I had obtained an average r^2 of about 0.24 so I thought ...
by aloplop
31 Dec 2008, 09:13
Forum: BCI Systems - User Applications
Topic: CAR in Spatial Filtering
Replies: 3
Views: 2361

CAR in Spatial Filtering

Hi again, Firstly, I would like to wish you a great year 2009. I would like to ask you one more question about spatial filtering. I have performed some sessions using these electrodes: C4 F4 T8 P4 Cz, what seems a Large Laplacian configuration. However, when I configured BCI2000´s Spatial Filter Blo...
by aloplop
10 Dec 2008, 06:32
Forum: BCI Systems - Signal Processing
Topic: Matched Filter
Replies: 13
Views: 5266

Hello, Finally, I decided to use a Matched FIR Filter of 32 samples. However, when I have to correlate a piece of the signal with a sine at the mu rhythm fundamental frequency I don´t know what would be the right length (in samples) of this sine in order to obtain the pattern for the matched filters...
by aloplop
26 Nov 2008, 12:02
Forum: BCI Systems - Signal Processing
Topic: FIR Filter
Replies: 3
Views: 2500

Hi again, thanks Jürgen for your quick response. I still have doubts about how can we now what is the number of samples of the EEG signal which are used for the convolution (i.e. the inputLength parameter). for( int sample = 0; sample < inputLength; ++sample ) result[sample] = inner_product( &mFilte...
by aloplop
25 Nov 2008, 12:46
Forum: BCI Systems - Signal Processing
Topic: FIR Filter
Replies: 3
Views: 2500

FIR Filter

Hi, I have looked the code for the last FIRFilter.cpp version. 1º) There, it appears for the integrations: case mean: Output( channel, 0 ) = result.sum() / inputLength; break; case rms: result *= result; Output( channel, 0 ) = ::sqrt( result.sum() ) / inputLength; break; also inputLength = Input.Ele...
by aloplop
18 Nov 2008, 12:39
Forum: BCI Systems - Signal Processing
Topic: Matched Filter
Replies: 13
Views: 5266

Hello, thanks for your advice...but I am not sure about what I should do.. sorry :( -> About the filter: As you have commented, in order to avoid the jitter produced by the phase of the brain signal I should create another "Matched Filter". In the version I have, cos(wt) functions are used, so I sho...
by aloplop
18 Nov 2008, 11:37
Forum: BCI Systems - Signal Processing
Topic: Normalizer offsets and gains
Replies: 5
Views: 3456

Hello, as it was commented on the last post, for my sessions online I perform 2 or 3 runs of about 20 trials in order to calibrate the normalizer before stop calibrating and perform the real session (which is 10 runs of 20 trials each). However, I have noticed that if I stop calibration at the end o...