Contributions:LiveAmpADC

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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 AUXbox. Tehre si one Trigger channel and 8 Digital I/=. There are 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:

LiveAmpADC.png

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.

See also

User Reference:Filters, Contributions:ADCs