Search found 979 matches

by Coen
Mon Nov 18, 2019 2:06 pm
Forum: EEG data analysis
Topic: One or more output arguments not assigned during call to "read_24bit"
Replies: 1
Views: 139

Re: One or more output arguments not assigned during call to "read_24bit"

Test the BDF file in the following two readers: https://www.biosemi.com/download/ToolsForRuntimeEngine861/BDFreader-808.zip http://www.teuniz.net/edfbrowser/ If the file is properly displayed without error messages in both the above readers, then the BDF file is not corrupt. Best regards, Coen (BioS...
by Coen
Thu Nov 14, 2019 1:40 pm
Forum: BioSemi Software (ActiView executable)
Topic: Data stops recording
Replies: 1
Views: 146

Re: Data stops recording

Your CFG is probably set to control the Pause button with triggers.

Edit the CFG in Notepad to (10th and 11th line from the end):

PauseOff=-1 //-1 is disabled, 0-255 is enabled
PauseOn=-1 //-1 is disabled, 0-255 is enabled

Best regards, Coen (BioSemi)
by Coen
Tue Nov 12, 2019 1:28 pm
Forum: BioSemi Hardware
Topic: Photosensor data
Replies: 1
Views: 149

Re: Photosensor data

The "noise" may be 50 Hz by room lightning. Test with the room lightning on and off (view the waveform in ActiView, switch the ERGO low-pass display filter off). It may also be due to modulation of the backlight of the monitor (test sensor with an on/off flashlight). In this case, only another monit...
by Coen
Fri Nov 01, 2019 5:19 pm
Forum: BioSemi Software (ActiView executable)
Topic: Testing e-Prime 2 Trigger Signal Timing in BioSemi
Replies: 1
Views: 135

Re: Testing e-Prime 2 Trigger Signal Timing in BioSemi

Use the microphone (see https://www.biosemi.com/accessoires.htm) and compare the timing of the audio pulse in the ERGO channel with the trigger from E-prime.

Best regards, Coen (BioSemi)
by Coen
Mon Oct 28, 2019 2:15 pm
Forum: BioSemi Software (ActiView executable)
Topic: Replay BDF files in ActiView
Replies: 3
Views: 217

Re: Replay BDF files in ActiView

24-bit data. little endian, with LSB = 31.25 nV. Signals are DC, so uV EEG superimposed on tens of mV offset (apply high-pass filter to cancel offsets).

Best regards, Coen (BioSemi)
by Coen
Tue Oct 22, 2019 12:05 pm
Forum: BioSemi Software (ActiView executable)
Topic: Replay BDF files in ActiView
Replies: 3
Views: 217

Re: Replay BDF files in ActiView

No need to hook up a subject: 1) Use "one bucket" method (see manual), make waves in the data by shaking the bucket. 2) Use "two bucket" method and use a signal generator with passive Ag-AgCl electrodes in the buckets. 3) If you have an AIB: select speedmode 4, 5, 6 or 7 and connect a signal generat...
by Coen
Tue Oct 08, 2019 2:49 pm
Forum: BioSemi all other topics
Topic: Processing sensor channels
Replies: 2
Views: 329

Re: Processing sensor channels

1) Yes, GSR processing has not changed 2) Yes, RESP and PLETH are in uV, but not calibrated. 3) First step is a little different: Signal1 = double(Non_inverting_Temp+2^30) - (Inverting_Temp-2^30) If I remember correctly (it's 20 years ago) the signal (Non_Inverting_Temp - Inverting_Temp) could overf...
by Coen
Tue Oct 08, 2019 12:04 pm
Forum: BioSemi Hardware
Topic: Error 5000
Replies: 3
Views: 1670

Re: Error 5000

Any USB cable is OK, also try a different USB port.

Best regards, Coen (BioSemi)
by Coen
Tue Sep 24, 2019 1:15 pm
Forum: ECG/EMG data analysis
Topic: CMS/DRL and reference with ECG signals
Replies: 4
Views: 470

Re: CMS/DRL and reference with ECG signals

1) Higher Common Mode
2) WCT reference offers standardized ECG waveforms

Best regards, Coen (BioSemi)
by Coen
Mon Sep 23, 2019 1:42 pm
Forum: ECG/EMG data analysis
Topic: CMS/DRL and reference with ECG signals
Replies: 4
Views: 470

Re: CMS/DRL and reference with ECG signals

1) For ECG, locate CMS on the chest. DRL can be anywhere on the body. 2) For hearttrate determination, just use two electrodes on the chest and process the difference (E1 -E2) in your BDF file reader. 3) Bipolar displayed signals are just differences between two raw channels (not affected by referen...
by Coen
Fri Sep 20, 2019 1:50 pm
Forum: BioSemi all other topics
Topic: Irregular Acquired Speed
Replies: 3
Views: 7379

Re: Irregular Acquired Speed

Accurate timing is only possible by supplying timestamps to the trigger port on the USB receiver (triggers are sampled synchronously with the EEG data).

Best regards, Coen (BioSemi)
by Coen
Tue Sep 17, 2019 2:25 pm
Forum: BioSemi Software (ActiView executable)
Topic: different trigger codes in bdf
Replies: 5
Views: 428

Re: different trigger codes in bdf

> I do not expect to be told to go to Google to get technical details about how to send markers. I direct you again to Google on the basic issue of how to split a 16 bit word into two 8 bit bytes during processing of the BDF file. This has nothing to do with sending triggers to the USB-receiver, For...
by Coen
Tue Sep 17, 2019 11:35 am
Forum: BioSemi Software (ActiView executable)
Topic: different trigger codes in bdf
Replies: 5
Views: 428

Re: different trigger codes in bdf

> I am still unsure as to why we have correct trigger codes when I use the decimal settings in ActiView, but then different ones in the .bdf file? Because for the ActiView display in "decimal" mode, the 16 bit trigger codes (see https://www.biosemi.com/faq/trigger_signals.htm and ) are split into tw...
by Coen
Mon Sep 16, 2019 9:23 pm
Forum: BioSemi Software (ActiView executable)
Topic: different trigger codes in bdf
Replies: 5
Views: 428

Re: different trigger codes in bdf

Split the 16 bit trigger word in two 8 bit bytes. ActiView does not affect the codes saved in the BDF file.

Best regards, Coen (BioSemi)
by Coen
Thu Sep 12, 2019 3:06 pm
Forum: ECG/EMG data analysis
Topic: offline heart rate extraction from ECG signal
Replies: 13
Views: 15695

Re: offline heart rate extraction from ECG signal

I would not agree with the above values because not much ECG information would be left in the outcome. Google on "ECG bandwidth" and you will find bandwidth recommendations in the order of 0.05-100 Hz (so at least 512 Hz sample rate). The LSB value used in the ActivTwo is publicized on https://www.b...
by Coen
Tue Aug 27, 2019 5:50 pm
Forum: BioSemi Software (ActiView executable)
Topic: Mssing Triggers
Replies: 12
Views: 904

Re: Mssing Triggers

Please sent the USB-receiver and trigger interface to BioSemi to check the hardware.

Best regards, Coen (BioSemi)
by Coen
Thu Aug 22, 2019 3:46 pm
Forum: BioSemi Software (ActiView executable)
Topic: Mssing Triggers
Replies: 12
Views: 904

Re: Mssing Triggers

Your trigger generation software seems OK: we see the triggers all perfectly in ActiView. Please confirm: did you (also) test with just the USB trigger interface connected to the USB-receiver ? So, without any other connection to the USB trigger interface (such as a splitter cable with connection to...
by Coen
Wed Aug 21, 2019 2:03 pm
Forum: BioSemi Software (ActiView executable)
Topic: Mssing Triggers
Replies: 12
Views: 904

Re: Mssing Triggers

Your tests prove that the BioSemi hard- and software is working correctly. Email you trigger generation program to info@biosemi.com.

Best regards, Coen (BioSemi)
by Coen
Mon Aug 19, 2019 3:12 pm
Forum: BioSemi Software (ActiView executable)
Topic: Mssing Triggers
Replies: 12
Views: 904

Re: Mssing Triggers

There might be a bad ground connection (pin 37). Check as follows:

Disconnect the USB cable from the USB-trigger interface. Plug just the USB-trigger interface (without USB-cable) into the USB-receiver and confirm that all triggers 1-16 change from HIGH to LOW.

Best regards, Coen (BioSemi)
by Coen
Fri Aug 16, 2019 1:57 pm
Forum: BioSemi Software (ActiView executable)
Topic: Mssing Triggers
Replies: 12
Views: 904

Re: Mssing Triggers

The blackbox toolkit (BBTK) system has a 25-pole TTL input connector. Did you actually make a 37 to 25 parallel cable ? Test the trigger port on the USB-receiver as described in post 4 in http://www.biosemi.nl/forum/viewtopic.php?f=1&p=3615#p3615 (short pin 1-16 to pin 37). If the port responds OK, ...
by Coen
Tue Aug 13, 2019 5:28 pm
Forum: BioSemi Software (ActiView executable)
Topic: Mssing Triggers
Replies: 12
Views: 904

Re: Mssing Triggers

How did you establish that you are actually sending triggers when you do not see them in ActiView ?

Best regards, Coen (BioSemi)
by Coen
Tue Aug 13, 2019 1:41 pm
Forum: BioSemi Hardware
Topic: Random '20202020...' triggers
Replies: 6
Views: 2416

Re: Random '20202020...' triggers

If 9 and 10 are not continuously high with detached cable, then the RespSwitch setting in the used CFG is still on "1", change it to "0". You state that all other trigger lines are high, but the picture shows line 16 low. Probably a hardware problem, but unrelated to the 9 and 10 behavior. You can i...
by Coen
Fri Aug 09, 2019 2:12 pm
Forum: BioSemi Hardware
Topic: Random '20202020...' triggers
Replies: 6
Views: 2416

Re: Random '20202020...' triggers

Disconnect the trigger cable from the USB-receiver. All trigger lines should now be high (if 9 and/or 10 are low, then there is still a wrong setting in the CFG). Then short pin 10 to pin 37. This should pull line 10 low (also compare with other lines). If line 10 does not respond, then sent the USB...
by Coen
Thu Aug 01, 2019 3:43 pm
Forum: BioSemi Software (ActiView executable)
Topic: Trigger Codes Missing Sporadically
Replies: 2
Views: 637

Re: Trigger Codes Missing Sporadically

1) Set the trigger format (lower left corner) to "analog" to troubleshoot. You can then identify 16 separate lines (bits). Colored dots/bars indicate a that a line is HIGH. grey background indicate that a line is LOW. 2) Use positive logic: HIGH is trigger. LOW is idle (with negative logic, triggers...
by Coen
Tue Jul 30, 2019 2:42 pm
Forum: EEG data analysis
Topic: merging BDFs?
Replies: 10
Views: 19441

Re: merging BDFs?

Install RTE 8.6 (http://ftp.ni.com/support/softlib/labview/labview_runtime/8.6.1/Windows/LVRTE861STD.exe) and run the merger86.exe Press "START", select the first and second BDF files from the successive popping up file dialogs, type the target file name in the third popup file dialog, and the merge...
by Coen
Tue Jun 11, 2019 12:40 pm
Forum: BioSemi Software (ActiView executable)
Topic: Reviewing 30sec epochs of streaming data in ActiView
Replies: 2
Views: 934

Re: Reviewing 30sec epochs of streaming data in ActiView

1) Use the "Screen Lenght" selector in the lower left corner of ActiView (stop acquisition to change x-axis). 2) Use a BDF file reader (e.g. https://www.biosemi.com/download/ToolsForRuntimeEngine861/BDFreader-808.zip or http://www.teuniz.net/edfbrowser/) to view the history while the file is written...
by Coen
Mon Jun 03, 2019 12:44 pm
Forum: BioSemi Software (ActiView executable)
Topic: Recording specific EXG channels
Replies: 1
Views: 925

Re: Recording specific EXG channels

Use "free choice" channel selection to display the channels of interest in the monopolar display. In the file dialog, choose "save as monopolar displayed". Save the setting in a new CFG ("about" tabpage).

Unused channels do not affect used channels.

Best regards, Coen
by Coen
Mon Jun 03, 2019 12:41 pm
Forum: BioSemi all other topics
Topic: High voltage levels in EEG output
Replies: 3
Views: 1116

Re: High voltage levels in EEG output

For the 24-bit data, use scaling LSB = 31.25 nV. Offsets up to 100 mV are normal.

Best regards, Coen (BioSemi)
by Coen
Mon Jun 03, 2019 12:39 pm
Forum: BioSemi Hardware
Topic: Delivering electric shocks while recording EEG
Replies: 3
Views: 1053

Re: Delivering electric shocks while recording EEG

The software is deliberately designed to only save the unfiltered (bandwidth: DC to 1/5th of the sample rate) and unreferenced data.

Best regards, Coen (BioSemi)
by Coen
Wed May 29, 2019 5:49 pm
Forum: BioSemi all other topics
Topic: High voltage levels in EEG output
Replies: 3
Views: 1116

Re: High voltage levels in EEG output

The data is DC: small EEG signals superimposed on large electrode offsets. Reject the offsets with a high-pass filter or baseline correction. Reference the data to reject large Common Mode, see https://www.biosemi.com/faq/cms&drl.htm --> http://www.biosemi.com/pics/zero_ref1_big.gif Best regards (Bi...