Contributions:actiCHampPlus
Synopsis
This module allows BCI2000 to collect data from Brain Vision's actiCHamp Plus amplifier. The actiCHamp Plus can be used with passive and active electrodes and is capable of reading from 32 up to 160 channels at 100kHz. To accommodate additional channels (ie. 64-160), additional modules are installed on the top of amp. The amplifier also has 8 auxiliary channels for gathering data from additional physiological sensors at up to 100kHz. The amplifier is powered by a lithium-ion battery pack to ensure long recording times. The amplifier is connected the computer running BCI2000 via USB. Note, the amplifier module must be plugged into the battery pack to function correctly.
Note: This source module is only available on Windows Machines.
Use
This module is included in the contributions section of BCI2000. It can be included by enabling the BUILD_CONTRIB in CMAKE before compiling BCI2000. After compiling, in the BCI2000/prog directory, there will be an executable called actiCHampPlus.exe. To then run BCI2000 with the executable, add Start executable actiCHampPlus to your batch file.
Known Issues
After the initial compile of the source module, there is sometimes an error that reads "No actiCHampPlus devices found. Try unplugging actiChampPlus and restarting BCI2000". To fix this error, go to BCI2000\src\contrib\SignalSource\actiCHampPlus\lib\dylib\<x64/x86>\, copy the file ActiChamp_<x64/x86>.dll and paste it in the BCI2000\prog directory. The file will already exist in that folder so when prompted, replace it.
Versioning
Author
Alex Belsten (belsten@neurotechcenter.org)
Source Code Revisions
- Initial development: 6037
- Tested under: 6039
- Known to compile under: 6064
- Broken since: N/A
Parameters
SourceCh
The number of channels that will be recorded from (EEG and auxiliary). Set this parameter to auto to automatically make the parameter equal to the TotalEEGChannels plus the number of elements in the AUXChList parameters.
ChannelNames
Names of each channel. If set to auto, the default is "Ch<#>" and "Aux<#>"
AUXChList
List of auxiliary channels to use. This parameter also defines the order in which BCI2000 stores and presents data.
TotalEEGChannels
Total number of EEG channels to record from.
SampleBlockSize
Number of samples that are transmitted at a time.
HardwareSamplingRate
Sampling at which the actiChamp is run. The actiChamp Plus can be run at three different frequencies: 10kHz, 50kHz and 100kHz.
SubSampleDivisor
Factor that decimates the hardware sampling rate. The hardware sampling rate is divided by this value to yield the actual sampling rate. This parameter has seven values: 1, 2, 5, 10, 20, 50, and 100.
SamplingRate
This parameter is defined by the hardware sampling rate and sub sample divisor. This parameter should always be set to 'auto'.
actiCHampAmplifierID
Index of the actiChamp Plus. For systems with one actiChamp Plus device, this parameter should be 0.
AcquisitionMode
1. Normal signal acquisition: Once connection to amplifier is established, data will be passed from the amplifier to BCI2000 normally.
2. Impedance measurement: Once connection to amplifier is established, BCI2000 will present the impedance for all channels. This data will be presented in a pop-up window for all of the EEG channels and the ground. Data will then be passed from the amplifier to BCI2000 normally. If active electrodes are being used, each electrode will illuminate an LED corresponding to the amount of impedance. If the impedance is low the electrode LED will be green. If the impedance is high the LED will be red, else it will be yellow.
ImpedancePauseTime
Amount of time to illuminate LEDs on active electrodes during impedance check. Helpful when trying to correct high impedance channels.
