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)
Search found 1125 matches
- Mon Oct 28, 2019 2:15 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Replay BDF files in ActiView
- Replies: 3
- Views: 10498
- Tue Oct 22, 2019 12:05 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Replay BDF files in ActiView
- Replies: 3
- Views: 10498
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...
- Tue Oct 08, 2019 2:49 pm
- Forum: BioSemi all other topics
- Topic: Processing sensor channels
- Replies: 2
- Views: 10273
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...
- Tue Oct 08, 2019 12:04 pm
- Forum: BioSemi Hardware
- Topic: Error 5000
- Replies: 3
- Views: 11640
Re: Error 5000
Any USB cable is OK, also try a different USB port.
Best regards, Coen (BioSemi)
Best regards, Coen (BioSemi)
- Tue Sep 24, 2019 1:15 pm
- Forum: ECG/EMG data analysis
- Topic: CMS/DRL and reference with ECG signals
- Replies: 4
- Views: 14792
Re: CMS/DRL and reference with ECG signals
1) Higher Common Mode
2) WCT reference offers standardized ECG waveforms
Best regards, Coen (BioSemi)
2) WCT reference offers standardized ECG waveforms
Best regards, Coen (BioSemi)
- Mon Sep 23, 2019 1:42 pm
- Forum: ECG/EMG data analysis
- Topic: CMS/DRL and reference with ECG signals
- Replies: 4
- Views: 14792
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...
- Fri Sep 20, 2019 1:50 pm
- Forum: BioSemi all other topics
- Topic: Irregular Acquired Speed
- Replies: 3
- Views: 17927
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)
Best regards, Coen (BioSemi)
- Tue Sep 17, 2019 2:25 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: different trigger codes in bdf
- Replies: 5
- Views: 12756
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...
- Tue Sep 17, 2019 11:35 am
- Forum: BioSemi Software (ActiView executable)
- Topic: different trigger codes in bdf
- Replies: 5
- Views: 12756
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...
- Mon Sep 16, 2019 9:23 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: different trigger codes in bdf
- Replies: 5
- Views: 12756
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)
Best regards, Coen (BioSemi)
- Thu Sep 12, 2019 3:06 pm
- Forum: ECG/EMG data analysis
- Topic: offline heart rate extraction from ECG signal
- Replies: 13
- Views: 35603
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...
- Tue Aug 27, 2019 5:50 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Mssing Triggers
- Replies: 12
- Views: 27030
Re: Mssing Triggers
Please sent the USB-receiver and trigger interface to BioSemi to check the hardware.
Best regards, Coen (BioSemi)
Best regards, Coen (BioSemi)
- Thu Aug 22, 2019 3:46 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Mssing Triggers
- Replies: 12
- Views: 27030
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...
- Wed Aug 21, 2019 2:03 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Mssing Triggers
- Replies: 12
- Views: 27030
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)
Best regards, Coen (BioSemi)
- Mon Aug 19, 2019 3:12 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Mssing Triggers
- Replies: 12
- Views: 27030
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)
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)
- Fri Aug 16, 2019 1:57 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Mssing Triggers
- Replies: 12
- Views: 27030
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, ...
- Tue Aug 13, 2019 5:28 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Mssing Triggers
- Replies: 12
- Views: 27030
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)
Best regards, Coen (BioSemi)
- Tue Aug 13, 2019 1:41 pm
- Forum: BioSemi Hardware
- Topic: Random '20202020...' triggers
- Replies: 6
- Views: 15346
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...
- Fri Aug 09, 2019 2:12 pm
- Forum: BioSemi Hardware
- Topic: Random '20202020...' triggers
- Replies: 6
- Views: 15346
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...
- Thu Aug 01, 2019 3:43 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Trigger Codes Missing Sporadically
- Replies: 2
- Views: 10211
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...
- Tue Jul 30, 2019 2:42 pm
- Forum: EEG data analysis
- Topic: merging BDFs?
- Replies: 10
- Views: 36181
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...
- Tue Jun 11, 2019 12:40 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Reviewing 30sec epochs of streaming data in ActiView
- Replies: 2
- Views: 10206
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...
- Mon Jun 03, 2019 12:44 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Recording specific EXG channels
- Replies: 1
- Views: 9213
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
Unused channels do not affect used channels.
Best regards, Coen
- Mon Jun 03, 2019 12:41 pm
- Forum: BioSemi all other topics
- Topic: High voltage levels in EEG output
- Replies: 3
- Views: 11255
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)
Best regards, Coen (BioSemi)
- Mon Jun 03, 2019 12:39 pm
- Forum: BioSemi Hardware
- Topic: Delivering electric shocks while recording EEG
- Replies: 3
- Views: 10109
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)
Best regards, Coen (BioSemi)
- Wed May 29, 2019 5:49 pm
- Forum: BioSemi all other topics
- Topic: High voltage levels in EEG output
- Replies: 3
- Views: 11255
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...
- Mon May 27, 2019 12:43 pm
- Forum: BioSemi Hardware
- Topic: Delivering electric shocks while recording EEG
- Replies: 3
- Views: 10109
Re: Delivering electric shocks while recording EEG
Apparently, the simulator jeopardizes ActiveTwo's perfect galvanic isolation provided by battery power and fiber-optic data transfer. This causes high Common Mode (50/60 Hz interference on all channels). Reject Common Mode by referencing. The simulator is probably mains powered or connected to mains...
- Tue May 07, 2019 12:47 pm
- Forum: EEG data analysis
- Topic: slow drifting on EEG
- Replies: 5
- Views: 21335
Re: slow drifting on EEG
CMS, DRL and the reference electrode can all be on the mastoids. However, CMS in the cap (approx. in the center of the other electrodes) is theoretically a bit better (Common Mode more equally distributed among the electrodes). DRL can be anywhere on the body.
Best regards, Coen (BioSemi)
Best regards, Coen (BioSemi)
- Fri Apr 12, 2019 5:07 pm
- Forum: BioSemi Hardware
- Topic: Odd ~17Hz noise in all channels
- Replies: 9
- Views: 16773
Re: Odd ~17Hz noise in all channels
It is normal with the DRL on the head. It is caused by a small amount of 16 Hz excitation current flowing from the GSR electrodes to the DRL electrode. The 16 Hz leakage is minimal when the GSR electrodes have equal impedance and offset. However, this is difficult to check and control. The 16 Hz is ...
- Mon Apr 01, 2019 3:23 pm
- Forum: BioSemi Software (ActiView executable)
- Topic: Matlab TCP Connection
- Replies: 4
- Views: 13774
Re: Matlab TCP Connection
1) Both computers should be connected to the same network. The transmission speed does affect lag. 2) Select the "Sent local Port" in ActiView. Ounce the connection is established, ActiView displays the "Remote Display Port" with the same number. 3) Check the select box "Add 7 Sensors". RESP is the ...