Contributions:LiveAmpADC
LiveAmpADC
Function
The LiveAmpADC filter acquires data from a LiveAmp wireless (Bluetooth) amplifier. The LiveAmp is an amplifier/digitizer combination from Brain Products. Support for this device in BCI2000 consists of a BCI2000-compatible Source Module (LiveAmpSource.exe).
LiveAmp Hardware
Either up to 32 referential EEG/ExG channels (with either passive or active electrodes) or up to 24 EEG/ExG referential channels plus up to 8 bipolar ExG channels (with passive electrodes only).\\ 8 AUX channel can be attached to AUX input, using the Sensor Trigger Extension. There is one Trigger channel and 8 Digital I/O. There is a built-in 3-axis acceleration sensor with 3 separate channels (x, y, z).\\ More on hardware can be found at: LiveAmp Technical details.
Installation
The BlueTooth dongle UBT21 must be installed first. The driver comes with the LiveAmp.
Parameters:LiveAmpADC
Parameters common to all source modules are described under User Reference:DataIOFilter. In addition, the LiveAmpADC provides the following parameters:
SerialNumber
Each LiveAmp has the serial number. The serial number can be found on the back of the amplifier. This number must be set as a parameter (without letters "LA-"). It is necessary for the Bluetooth connection
SourceCh
The total number of channels: EEG + AUX + Acc + Triggers (see parameters below).
SampleBlockSize
Samples per channel per digitized block. Together with the sampling rate, this parameter determines how often per second data are collected, processed, and feedback is updated. For example, at 500 Hz sampling and a SampleBlockSize of 20, the system (e.g., source signal display, signal processing, and stimulus presentation) will be updated 25 times per second.
SamplingRate
The sample rate of the system. All data is either acquired at 250, 500 or 1000Hz In case you are experiencing problems by higher sampling rates (e.g., data loss, jerky display, etc.), increase the SampleBlockSize so that you are updating the system less frequently (usually, updating the system 20-30 times per second is sufficient for most applications), and increase Visualize->VisualizeSourceDecimation. This parameter will decrease the number of samples per second that are actually drawn in the Source display.
SourceChGain
Gain for each channel.
SourceChOffset
Offset for each channel.
ChannelNames
Names of each channel.
AcquisitionMode
Data acquisition mode, it can be:
- inactive - no recording
- analog signal acquisition - standard recording mode
- test signal - a test signal, same on all channels
Parameters:LiveAmp
EegChList
List of indexes of EEG channels used. For example, you can write index in any order, like: 21, 3, 5, 6, 7, 8 (the order of channels does not matter). That means that only 6 EEG physical channels will be recorder: 3,5,6,7,8 and 21. Channels may not be listed twice.
BipolarChannels
Checking this option the last 8 of 32 channels will be bipolar. When user wants to record bipolar channel, he/she must put appropriate indexes in the 'EegCHList' (indexes between 25 and 32).
AuxChList
List of indexes of AUX channels. For example, if there are 6 AUX available, you can put 1, 2, 5, 6. That mans that only 4 AUX channel will be recorder, with indexes 1,2, 5 and 6.
ACCList
List of indexes of Acc (acceleration sensor) channels. There are 3 Acc channels, with indexes 1(x), 2(y) and 3(z).
TriggerChList
List of indexes of trigger channels. There is one analog and 8 digital channels. The order of indexes can be used in the same manner as EEG and AUX channel indexes.