Search found 1004 matches

by Coen
Tue Feb 16, 2021 6:03 pm
Forum: BioSemi Software (ActiView executable)
Topic: ActiView: LabView Resource not found
Replies: 2
Views: 123

Re: ActiView: LabView Resource not found

lvanlys.dll, lvinput.dll and RingBuffer.dll are in the zip download from our website. Make sure that these three dll's are in the same folder (or a subfolder) as the ActiView.exe.

Best regards, Coen (BioSemi)
by Coen
Tue Feb 09, 2021 12:46 pm
Forum: EEG data analysis
Topic: Swapped head side and amp slots
Replies: 3
Views: 189

Re: Swapped head side and amp slots

Yes
by Coen
Mon Feb 08, 2021 7:07 pm
Forum: EEG data analysis
Topic: Swapped head side and amp slots
Replies: 3
Views: 189

Re: Swapped head side and amp slots

The B slot does not have the CMS/DRL connections. If you did not use a separate CMS/DRL, then the Common Mode was not in range (blue light blinking) and unfortunately your data is useless (no power to active electrodes).

Best regards, Coen (BioSemi)
by Coen
Fri Feb 05, 2021 12:14 pm
Forum: BioSemi Hardware
Topic: Unknown(and unexcpected) noise
Replies: 1
Views: 209

Re: Unknown(and unexcpected) noise

Blue light blinking ? Common Mode was not in range, confirm by checking the trigger/status channel in the BDF file. For solutions, see https://www.biosemi.com/faq/check_electrodes.htm . Data measured with blinking blue light is meaningless because power to the active electrodes is cut off. Best rega...
by Coen
Fri Jan 22, 2021 6:58 pm
Forum: BioSemi Hardware
Topic: Triggers with arduino board
Replies: 1
Views: 245

Re: Triggers with arduino board

Connect the digital outputs of the Arduino to the trigger port of the USB-receiver (pin 1-16 are trigger inputs, pin 37 is ground, see https://www.biosemi.com/faq/trigger_signals.htm ). Both 3.3V and 5V output will work OK.

Best regards, Coen (BioSemi)
by Coen
Tue Jan 19, 2021 2:44 pm
Forum: BioSemi Hardware
Topic: Post hoc measurement of EEG quality
Replies: 3
Views: 549

Re: Post hoc measurement of EEG quality

Offset is just the average of a few seconds data (or low-passed data with a cut-off frequency < 1 sec) Inject just enough gel to fill the holder, but not more (or you may introduce gel bridges). Use (rotate) the tip of the syringe to gentle work the gel between the hair onto the skin. The electrode ...
by Coen
Thu Jan 07, 2021 10:54 pm
Forum: BioSemi Hardware
Topic: Post hoc measurement of EEG quality
Replies: 3
Views: 549

Re: Post hoc measurement of EEG quality

Offsets are readily extracted from the data, see http://www.biosemi.nl/forum/viewtopic.php?t=56

Best regards, Coen (BioSemi)
by Coen
Tue Dec 08, 2020 5:55 pm
Forum: BioSemi Software (ActiView executable)
Topic: send ECG data measured by Biosemi to another device.
Replies: 4
Views: 954

Re: send ECG data measured by Biosemi to another device.

Use the TCP/IP link in ActiView and a client example from https://www.biosemi.com/download.htm (available in LabVIEW or MatLab).

Best regards, Coen (BioSemi)
by Coen
Fri Nov 27, 2020 1:44 pm
Forum: BioSemi all other topics
Topic: Send triggers from DATAPixx3 / TRACKPixx3 system to BioSemi system
Replies: 2
Views: 872

Re: Send triggers from DATAPixx3 / TRACKPixx3 system to BioSemi system

Make a parallel cable to connect the 25-pole trigger output connector of the DATAPixx3 to the 37-pole trigger input on the BioSemi USB-receiver. The BioSemi "Presentation" cable will probably work (compare the pinout of the DATAPixx3 with https://www.biosemi.com/faq/presentation.htm ) Best regards, ...
by Coen
Thu Oct 29, 2020 2:28 pm
Forum: BioSemi Software (ActiView executable)
Topic: additional triggers changing sampling rate from 2048 Hz to 256 Hz
Replies: 3
Views: 818

Re: additional triggers changing sampling rate from 2048 Hz to 256 Hz

When decimating from 2048 to 256 Hz, an OR function is applied to trigger bits within each group of 8 original samples. A repetition of very short (millisecond) triggers can therefore appear as a single trigger in the decimated file. So, no triggers are missed (provided positive trigger logic is use...
by Coen
Tue Oct 27, 2020 9:47 pm
Forum: BioSemi Software (ActiView executable)
Topic: additional triggers changing sampling rate from 2048 Hz to 256 Hz
Replies: 3
Views: 818

Re: additional triggers changing sampling rate from 2048 Hz to 256 Hz

ActiView does not allow you to change the sample rate while saving data to file (decimation selector is grayed out while saving). Any unexpected triggers seen in EEGLAB (that reads the BDF file) must have another explanation.

Best regards, Coen (BioSemi)
by Coen
Thu Oct 01, 2020 3:17 pm
Forum: BioSemi Hardware
Topic: EOG - Direct current (DC) versus Alternatice current (AC)
Replies: 1
Views: 823

Re: EOG - Direct current (DC) versus Alternatice current (AC)

The BioSemi ActiveTwo system has a DC amplifier, signals saved to file are always DC. Switch the high-pass filter (left sidebar) off to display the signals in DC mode during recording. Note: the filters (as well as all other controls) in the left sidebar do not affect the data saved to file. Bandwid...
by Coen
Wed Sep 30, 2020 6:56 pm
Forum: BioSemi all other topics
Topic: recording configuration problem
Replies: 1
Views: 746

Re: recording configuration problem

The BDF file recorded with default.cfg should be fully OK, but with A1...B32 labeling instead of the 1020 labels. The conversion between the two label styles for 64 channels is shown in https://www.biosemi.com/pics/cap_64_layout_medium.jpg . The prevent the mistake in the future, you could consider ...
by Coen
Tue Sep 01, 2020 12:44 pm
Forum: BioSemi Hardware
Topic: Biosemi in hand luggage
Replies: 1
Views: 887

Re: Biosemi in hand luggage

The battery-box is the only problem component. The non-spillable sealed lead-acid battery is certified for carrying on airplanes. The battery must be properly labeled, and the safety data sheet (MSDS) must be presented on request. Please email to info@biosemi.com for copies of the label and MSDS. Be...
by Coen
Wed Aug 26, 2020 9:11 pm
Forum: BioSemi Hardware
Topic: EEG with black people's hair in mind
Replies: 4
Views: 1787

Re: EEG with black people's hair in mind

The BioSemi system uses innovative active electrodes. The active electrodes tolerate high electrode impednaces (up to hundreds kiloOhm). So long as the electrode offsets are within the acceptable range (say between +100 mV and - 100 mV) and stable, clean EEG signals can be acquired. Skin preparation...
by Coen
Mon Aug 17, 2020 2:54 pm
Forum: BioSemi all other topics
Topic: Error opening .bdf file
Replies: 1
Views: 923

Re: Error opening .bdf file

Repair false "enter" characters in the header with: https://www.biosemi.com/download/RepairEnter.zip Repair "unknown" file length value in the header with: https://www.biosemi.com/download/Repair16.zip Test repaired BDF file with: https://www.biosemi.com/download/ToolsForRuntimeEngine2016/BDFreader2...
by Coen
Sat Jul 11, 2020 9:59 pm
Forum: BioSemi Hardware
Topic: Lowpass filter
Replies: 2
Views: 1299

Re: Lowpass filter

1/5th is an approximation, 104 Hz is the correct -3dB frequency, for the response of the CIC filter see https://www.biosemi.com/faq/adjust_filter.htm

Best regards, Coen (BioSemi)
by Coen
Mon Jul 06, 2020 3:41 pm
Forum: BioSemi all other topics
Topic: Covid 19
Replies: 1
Views: 923

Re: Covid 19

See https://www.biosemi.com/faq/covid19.htm

Best regards, Coen (BioSemi)
by Coen
Mon Mar 09, 2020 3:25 pm
Forum: BioSemi Hardware
Topic: Removing electrodes from pinset
Replies: 3
Views: 2690

Re: Removing electrodes from pinset

Add a Headbox, see https://www.biosemi.com/accessoires.htm

Best regards, Coen (BioSemi)
by Coen
Thu Mar 05, 2020 7:16 pm
Forum: BioSemi Hardware
Topic: Removing electrodes from pinset
Replies: 3
Views: 2690

Re: Removing electrodes from pinset

Use 6 so called TP-pin electrodes connected to the EX inputs.

Best regards, Coen (BioSemi)
by Coen
Wed Feb 12, 2020 1:57 pm
Forum: BioSemi Software (ActiView executable)
Topic: Event related average rectify
Replies: 1
Views: 2598

Re: Event related average rectify

ActiView is offered as open-source LabVIEW to allow users to add functionality as you propose. Use LabVIEW 8.6 or higher for ActiView 7.xx and LabVIEW 2016 or higher for ActiView 8.xx. Only very basic LabVIEW skills are needed for what you want to add.

Best regards, Coen (BioSemi)
by Coen
Fri Jan 31, 2020 4:08 pm
Forum: EEG data analysis
Topic: Difficulties to see the triggers
Replies: 1
Views: 2458

Re: Difficulties to see the triggers

The triggers are in the last channel of the BDF file, see https://www.biosemi.com/faq/file_format.htm and https://www.biosemi.com/faq/trigger_signals.htm

Best regards, Coen (BioSemi)
by Coen
Tue Jan 14, 2020 10:43 pm
Forum: EEG data analysis
Topic: Quick question about bit 16 (High when new Epoch is started) in trigger status channel
Replies: 1
Views: 2052

Re: Quick question about bit 16 (High when new Epoch is started) in trigger status channel

You are right, EEGLAB is wrong. The rising edge of the START EPOCH bit just indicates the start of an epoch after the recording was paused. The high-state duration of the START EPOCH bit has no meaning.

Best regards, Coen (BioSemi)
by Coen
Mon Dec 23, 2019 5:35 pm
Forum: EEG data analysis
Topic: Channel location_child's cap
Replies: 2
Views: 2417

Re: Channel location_child's cap

Enter the head circumference for the child in the coordinates Excel sheet (field G9): https://www.biosemi.com/download/Cap_coords_all.xls

Best regards, Coen (BioSemi)
by Coen
Thu Nov 21, 2019 7:03 pm
Forum: EEG data analysis
Topic: One or more output arguments not assigned during call to "read_24bit"
Replies: 3
Views: 2998

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

If the two above readers work OK, then the file is definitely OK and nothing unusual happened during recording.

The error must be in your specific reader.

Best regards, Coen (BioSemi)
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: 3
Views: 2998

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: 2294

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: 2471

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: 2
Views: 2805

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: 2954

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)