BCI2000 Wiki - User contributions [en]

Contributions:CereStim

2021-07-23T20:46:43Z

Abelsten: /* StimulationConfigurations */

==Versioning==
[[File:Cerestim.jpg|400px|thumb|right|Blackrock CereStim 96.]]
===Author===
Alexander Belsten (belsten@neurotechcenter.org)

===Version History===
* 2021/07/21 - R6337 - Initial private release for internal testing.

===Source Code Revisions===
*Initial development: 6337
*Known to compile under: 6340
*Broken since: --

==Functional Description==
This output extension integrates the Blackrock CereStim 96 intracranial stimulator with BCI2000. This integration enables automated stimulation of up to 96 electrodes with 15 different stimulation waveforms.

==Integration into BCI2000==
Enable the extension in your CMake configuration, enable <code>EXTENSIONS_CERESTIM=On</code> in the Extensions folder of the CMake GUI and then generate the BCI2000 Visual Studio solution in CMake. Next, open the solution with Visual Studio and rebuild the ''BCI2000FrameworkAppModule'', and then rebuild any user application module you want to use the extension with. Once the extension is built into the user application, you can enable it by appending <code>--EnableCereStim=1</code> to the user application module start executable command in your batch file.

==Parameters==
The CereStim is configured in the "CereStim" tab. The configurable parameters are:

===AppliedVoltage===
The CereStim drives current, so the applied voltage fluctuates according to the impedance between the current source (electrode) and drain. This dropdown parameter sets the maximum applied voltage (there will be no notification that this maximum has been met).

===AppliedCurrent===
This parameter sets the maximum applied current in microamps. Unlike the applied voltage, which fluctuates and therefore may or may not hit the maximum, this parameter serves the purpose of being a safety check for your uploaded stimulation configurations. Thus, to be 100% sure you are not stimulating above a desired current value, you can set this parameter to that maximum. If set to auto, the default will be the maximum current the CereStim can stimulate with.

===AppliedPhaseCharge===
This parameter sets the maximum applied phase charge, where <code>charge=amplitude*width</code>. Amplitude is the current amplitude in microamps, and width is phase duration in microseconds. If set to auto, this parameter will default to the maximum value.

===AppliedFrequency===
This parameter sets the maximum frequency that stimulation pulses can have in Hz. If set to auto, this value defaults to the maximum.

===StimulationConfigurations===

<gallery mode="packed" widths=400px heights=400px>
File:cerestim_stimulation_definition.png|Figure 1: Stimulation pulse shape definition.
</gallery>
<gallery mode="packed" widths=350px heights=350px>
File:cerestim_stimulation_configurations.png|Figure 2: Stimulation pulse shape definition in BCI2000.
</gallery>
This parameter is where stimulation pulses are defined. You can define up to 15 different stimulations pulses. The pulse shapes are defined according to Fig. 1.For each configuration, if the ''Cathode first'' row is <code>1</code>, then the positive magnitude pulse comes first. If this row is <code>0</code>, then the negative pulse comes first. The current sink for each pulse is the patient ground, which is the green safety connector on the back of the CereStim. However, suppose you wish to stimulate between two different electrodes within the brain. In that case, you can make two configurations that have the same pulse shape parameters but have reversed ''Cathode first'' parameters. Current can still potentially flow to the patient ground, but if the impedance between the two electrodes is significantly less than the impedance between the electrodes and patient ground, then the majority of the current will flow between the two electrodes. Information on how to define these two electrodes can be found in [https://www.bci2000.org/mediawiki/index.php/Contributions:CereStim#StimulationTriggers StimulationTriggers] parameter. Note that valid frequencies depend on the phase and interphase duration of the pulse.

===StimulationTriggers===
<gallery mode="packed" widths=350px heights=350px>
File:cerestim_stimulation_triggers.png|Figure 3: Stimulation triggers have an expression, configuration ID, and list of electrodes.
</gallery>
This parameter defines when electrodes are stimulated, with what configuration they are stimulated with, and what electrodes are stimulated. The ''Expression'' row defines when electrodes are stimulated by specifying a [https://www.bci2000.org/mediawiki/index.php/User_Reference:Expression_Syntax BCI2000 expression]. When this expression evaluates true, the electrodes will be stimulated with the pulse shape defined in the ''Configuration ID'' row. Note that two columns can have the same ''Expression'', which allows for concurrent stimulation between different electrode locations. The ''Configuration ID'' defines the applied pulse shape and corresponds to the column number in the ''StimulationConfiguration'' parameter. Lastly, the ''Electrode(s)'' row specifies which electrodes will be stimulation. Elements in this row can be single values that specify a single electrode, or an embedded list in which you can specify multiple electrodes (from 1-96).

'''Note:''' You can only stimulate up to '''15''' electrodes concurrently. Concurrent stimulation groups, as defined by their equivalent ''Expression'' expression, must also have disjoint electrode lists.

===DeviceInfo===
This parameter is auto-populated with information about the hardware and firmware versions of the CereStim stimulator that is connected. This information will be viewable during offline analysis by opening the resulting <code>.dat</code> file.

==States==
===CereStimStimulation===
This binary state is equal to <code>1</code> when stimulation is being applied.

==Latency==
[[File:cerestim_stimulation_latency.png|400px|thumb|right|upright=2.5|Figure 4: Latency of stimulation is about 17.3ms on average.]]
Figure 4 shows the latency of stimulation over 220 trials. Stimulation pulses were acquired using a gUSBamp at 38.4kHz and a block size of 50ms.

==See also==
*[[Contributions:Extensions]]
*[[Contributions:g.EstimSwitchingUnit]]
*[[Contributions:gEstimFilter]]
*[[CortecADC]]
[[Category:Contributions]][[Category:Extension]]

Contributions:CereStim

2021-07-23T20:37:34Z

Abelsten: /* Versioning */

==Versioning==
[[File:Cerestim.jpg|400px|thumb|right|Blackrock CereStim 96.]]
===Author===
Alexander Belsten (belsten@neurotechcenter.org)

===Version History===
* 2021/07/21 - R6337 - Initial private release for internal testing.

===Source Code Revisions===
*Initial development: 6337
*Known to compile under: 6340
*Broken since: --

==Functional Description==
This output extension integrates the Blackrock CereStim 96 intracranial stimulator with BCI2000. This integration enables automated stimulation of up to 96 electrodes with 15 different stimulation waveforms.

==Integration into BCI2000==
Enable the extension in your CMake configuration, enable <code>EXTENSIONS_CERESTIM=On</code> in the Extensions folder of the CMake GUI and then generate the BCI2000 Visual Studio solution in CMake. Next, open the solution with Visual Studio and rebuild the ''BCI2000FrameworkAppModule'', and then rebuild any user application module you want to use the extension with. Once the extension is built into the user application, you can enable it by appending <code>--EnableCereStim=1</code> to the user application module start executable command in your batch file.

==Parameters==
The CereStim is configured in the "CereStim" tab. The configurable parameters are:

===AppliedVoltage===
The CereStim drives current, so the applied voltage fluctuates according to the impedance between the current source (electrode) and drain. This dropdown parameter sets the maximum applied voltage (there will be no notification that this maximum has been met).

===AppliedCurrent===
This parameter sets the maximum applied current in microamps. Unlike the applied voltage, which fluctuates and therefore may or may not hit the maximum, this parameter serves the purpose of being a safety check for your uploaded stimulation configurations. Thus, to be 100% sure you are not stimulating above a desired current value, you can set this parameter to that maximum. If set to auto, the default will be the maximum current the CereStim can stimulate with.

===AppliedPhaseCharge===
This parameter sets the maximum applied phase charge, where <code>charge=amplitude*width</code>. Amplitude is the current amplitude in microamps, and width is phase duration in microseconds. If set to auto, this parameter will default to the maximum value.

===AppliedFrequency===
This parameter sets the maximum frequency that stimulation pulses can have in Hz. If set to auto, this value defaults to the maximum.

===StimulationConfigurations===

<gallery mode="packed" widths=300px heights=300px>
File:cerestim_stimulation_definition.png|Figure 1: Stimulation pulse shape definition.
File:cerestim_stimulation_configurations.png|Figure 2: Stimulation pulse shape definition in BCI2000.
</gallery>
This parameter is where stimulation pulses are defined. You can define up to 15 different stimulations pulses. The pulse shapes are defined according to Fig. 1.For each configuration, if the ''Cathode first'' row is <code>1</code>, then the positive magnitude pulse comes first. If this row is <code>0</code>, then the negative pulse comes first. The current sink for each pulse is the patient ground, which is the green safety connector on the back of the CereStim. However, suppose you wish to stimulate between two different electrodes within the brain. In that case, you can make two configurations that have the same pulse shape parameters but have reversed ''Cathode first'' parameters. Current can still potentially flow to the patient ground, but if the impedance between the two electrodes is significantly less than the impedance between the electrodes and patient ground, then the majority of the current will flow between the two electrodes. Information on how to define these two electrodes can be found in [https://www.bci2000.org/mediawiki/index.php/Contributions:CereStim#StimulationTriggers StimulationTriggers] parameter. Note that valid frequencies depend on the phase and interphase duration of the pulse.

===StimulationTriggers===
<gallery mode="packed" widths=350px heights=350px>
File:cerestim_stimulation_triggers.png|Figure 3: Stimulation triggers have an expression, configuration ID, and list of electrodes.
</gallery>
This parameter defines when electrodes are stimulated, with what configuration they are stimulated with, and what electrodes are stimulated. The ''Expression'' row defines when electrodes are stimulated by specifying a [https://www.bci2000.org/mediawiki/index.php/User_Reference:Expression_Syntax BCI2000 expression]. When this expression evaluates true, the electrodes will be stimulated with the pulse shape defined in the ''Configuration ID'' row. Note that two columns can have the same ''Expression'', which allows for concurrent stimulation between different electrode locations. The ''Configuration ID'' defines the applied pulse shape and corresponds to the column number in the ''StimulationConfiguration'' parameter. Lastly, the ''Electrode(s)'' row specifies which electrodes will be stimulation. Elements in this row can be single values that specify a single electrode, or an embedded list in which you can specify multiple electrodes (from 1-96).

'''Note:''' You can only stimulate up to '''15''' electrodes concurrently. Concurrent stimulation groups, as defined by their equivalent ''Expression'' expression, must also have disjoint electrode lists.

===DeviceInfo===
This parameter is auto-populated with information about the hardware and firmware versions of the CereStim stimulator that is connected. This information will be viewable during offline analysis by opening the resulting <code>.dat</code> file.

==States==
===CereStimStimulation===
This binary state is equal to <code>1</code> when stimulation is being applied.

==Latency==
[[File:cerestim_stimulation_latency.png|400px|thumb|right|upright=2.5|Figure 4: Latency of stimulation is about 17.3ms on average.]]
Figure 4 shows the latency of stimulation over 220 trials. Stimulation pulses were acquired using a gUSBamp at 38.4kHz and a block size of 50ms.

==See also==
*[[Contributions:Extensions]]
*[[Contributions:g.EstimSwitchingUnit]]
*[[Contributions:gEstimFilter]]
*[[CortecADC]]
[[Category:Contributions]][[Category:Extension]]

Contributions:CereStim

2021-07-23T20:37:09Z

Abelsten:

==Versioning==
[[File:Cerestim.jpg|400px|thumb|right|Blackrock CereStim 96]]
===Author===
Alexander Belsten (belsten@neurotechcenter.org)

===Version History===
* 2021/07/21 - R6337 - Initial private release for internal testing.

===Source Code Revisions===
*Initial development: 6337
*Known to compile under: 6340
*Broken since: --

==Functional Description==
This output extension integrates the Blackrock CereStim 96 intracranial stimulator with BCI2000. This integration enables automated stimulation of up to 96 electrodes with 15 different stimulation waveforms.

==Integration into BCI2000==
Enable the extension in your CMake configuration, enable <code>EXTENSIONS_CERESTIM=On</code> in the Extensions folder of the CMake GUI and then generate the BCI2000 Visual Studio solution in CMake. Next, open the solution with Visual Studio and rebuild the ''BCI2000FrameworkAppModule'', and then rebuild any user application module you want to use the extension with. Once the extension is built into the user application, you can enable it by appending <code>--EnableCereStim=1</code> to the user application module start executable command in your batch file.

==Parameters==
The CereStim is configured in the "CereStim" tab. The configurable parameters are:

===AppliedVoltage===
The CereStim drives current, so the applied voltage fluctuates according to the impedance between the current source (electrode) and drain. This dropdown parameter sets the maximum applied voltage (there will be no notification that this maximum has been met).

===AppliedCurrent===
This parameter sets the maximum applied current in microamps. Unlike the applied voltage, which fluctuates and therefore may or may not hit the maximum, this parameter serves the purpose of being a safety check for your uploaded stimulation configurations. Thus, to be 100% sure you are not stimulating above a desired current value, you can set this parameter to that maximum. If set to auto, the default will be the maximum current the CereStim can stimulate with.

===AppliedPhaseCharge===
This parameter sets the maximum applied phase charge, where <code>charge=amplitude*width</code>. Amplitude is the current amplitude in microamps, and width is phase duration in microseconds. If set to auto, this parameter will default to the maximum value.

===AppliedFrequency===
This parameter sets the maximum frequency that stimulation pulses can have in Hz. If set to auto, this value defaults to the maximum.

===StimulationConfigurations===

<gallery mode="packed" widths=300px heights=300px>
File:cerestim_stimulation_definition.png|Figure 1: Stimulation pulse shape definition.
File:cerestim_stimulation_configurations.png|Figure 2: Stimulation pulse shape definition in BCI2000.
</gallery>
This parameter is where stimulation pulses are defined. You can define up to 15 different stimulations pulses. The pulse shapes are defined according to Fig. 1.For each configuration, if the ''Cathode first'' row is <code>1</code>, then the positive magnitude pulse comes first. If this row is <code>0</code>, then the negative pulse comes first. The current sink for each pulse is the patient ground, which is the green safety connector on the back of the CereStim. However, suppose you wish to stimulate between two different electrodes within the brain. In that case, you can make two configurations that have the same pulse shape parameters but have reversed ''Cathode first'' parameters. Current can still potentially flow to the patient ground, but if the impedance between the two electrodes is significantly less than the impedance between the electrodes and patient ground, then the majority of the current will flow between the two electrodes. Information on how to define these two electrodes can be found in [https://www.bci2000.org/mediawiki/index.php/Contributions:CereStim#StimulationTriggers StimulationTriggers] parameter. Note that valid frequencies depend on the phase and interphase duration of the pulse.

===StimulationTriggers===
<gallery mode="packed" widths=350px heights=350px>
File:cerestim_stimulation_triggers.png|Figure 3: Stimulation triggers have an expression, configuration ID, and list of electrodes.
</gallery>
This parameter defines when electrodes are stimulated, with what configuration they are stimulated with, and what electrodes are stimulated. The ''Expression'' row defines when electrodes are stimulated by specifying a [https://www.bci2000.org/mediawiki/index.php/User_Reference:Expression_Syntax BCI2000 expression]. When this expression evaluates true, the electrodes will be stimulated with the pulse shape defined in the ''Configuration ID'' row. Note that two columns can have the same ''Expression'', which allows for concurrent stimulation between different electrode locations. The ''Configuration ID'' defines the applied pulse shape and corresponds to the column number in the ''StimulationConfiguration'' parameter. Lastly, the ''Electrode(s)'' row specifies which electrodes will be stimulation. Elements in this row can be single values that specify a single electrode, or an embedded list in which you can specify multiple electrodes (from 1-96).

'''Note:''' You can only stimulate up to '''15''' electrodes concurrently. Concurrent stimulation groups, as defined by their equivalent ''Expression'' expression, must also have disjoint electrode lists.

===DeviceInfo===
This parameter is auto-populated with information about the hardware and firmware versions of the CereStim stimulator that is connected. This information will be viewable during offline analysis by opening the resulting <code>.dat</code> file.

==States==
===CereStimStimulation===
This binary state is equal to <code>1</code> when stimulation is being applied.

==Latency==
[[File:cerestim_stimulation_latency.png|400px|thumb|right|upright=2.5|Figure 4: Latency of stimulation is about 17.3ms on average.]]
Figure 4 shows the latency of stimulation over 220 trials. Stimulation pulses were acquired using a gUSBamp at 38.4kHz and a block size of 50ms.

==See also==
*[[Contributions:Extensions]]
*[[Contributions:g.EstimSwitchingUnit]]
*[[Contributions:gEstimFilter]]
*[[CortecADC]]
[[Category:Contributions]][[Category:Extension]]

==Versioning==
[[File:CereStim.jpg|400px|thumb|right|Blackrock CereStim 96]]
===Author===
Alexander Belsten (belsten@neurotechcenter.org)

===Version History===
* 2021/07/21: Initial release

===Source Code Revisions===
*Initial development: 6337
*Known to compile under: 6337
*Broken since: --

==Functional Description==
This output extension integrates the Blackrock CereStim 96 intracranial stimulator with BCI2000. This integration enables automated stimulation of up to 96 electrodes with 15 different stimulation waveforms.

==Integration into BCI2000==
Enable the extension in your CMake configuration, enable EXTENSIONS_CERESTIM=On in the Extensions folder of the CMake GUI and then generate the BCI2000 Visual Studio solution in CMake. Next, open the solution with Visual Studio and rebuild the BCI2000FrameworkAppModule, and then rebuild any user application module you want to use the extension with. Once the extension is built into the user application, you can enable it by appending --EnableCereStim=1 to the user application module start executable command in your batch file.

==Parameters==
The CereStim is configured in the "CereStim" tab. The configurable parameters are:

===AppliedVoltage===

===AppliedCurrent===

===AppliedPhaseCharge===

===AppliedFrequency===

===StimulationConfigurations===

===StimulationTriggers===

===DeviceInfo===

==States==
===CereStimStimulation===

==Latency==

Contributions:CereStim

2021-07-21T14:09:28Z

Abelsten:

==Versioning==

===Author===
Alexander Belsten (belsten@neurotechcenter.org)

===Version History===
* 2021/07/21: Initial release

===Source Code Revisions===
*Initial development: 6337
*Known to compile under: 6337
*Broken since: --

==Functional Description==
This output extension integrates the Blackrock CereStim 96 intracranial stimulator with BCI2000. This integration enables automated stimulation of up to 96 electrodes with 15 different stimulation waveforms.

==Integration into BCI2000==
Enable the extension in your CMake configuration, enable EXTENSIONS_CERESTIM=On in the Extensions folder of the CMake GUI and then generate the BCI2000 Visual Studio solution in CMake. Next, open the solution with Visual Studio and rebuild the BCI2000FrameworkAppModule, and then rebuild any user application module you want to use the extension with. Once the extension is built into the user application, you can enable it by appending --EnableCereStim=1 to the user application module start executable command in your batch file.

==Parameters==
The CereStim is configured in the "CereStim" tab. The configurable parameters are:

===AppliedVoltage===

===AppliedCurrent===

===AppliedPhaseCharge===

===AppliedFrequency===

===StimulationConfigurations===

===StimulationTriggers===

===DeviceInfo===

==States==
===CereStimStimulation===

==Latency==

File:Cerestim.jpg

2021-07-21T14:08:51Z

Abelsten:

Contributions:CereStim

2021-07-21T13:30:04Z

Abelsten: Created page with "==Versioning==  ===Author=== Alexander Belsten (belsten@neurotechcenter.org) ===Vers..."

==Versioning==

===Author===
Alexander Belsten (belsten@neurotechcenter.org)

===Version History===
* 2021/07/21: Initial release

===Source Code Revisions===
*Initial development: 6337
*Known to compile under: 6337
*Broken since: --

==Functional Description==
This output extension integrates the Blackrock CereStim 96 intracranial stimulator with BCI2000. This integration enables automated stimulation of up to 96 electrodes with 15 different stimulation waveforms.

==Integration into BCI2000==
Enable the extension in your CMake configuration, enable EXTENSIONS_CERESTIM=On in the Extensions folder of the CMake GUI and then generate the BCI2000 Visual Studio solution in CMake. Next, open the solution with Visual Studio and rebuild the BCI2000FrameworkAppModule, and then rebuild any user application module you want to use the extension with. Once the extension is built into the user application, you can enable it by appending --EnableCereStim=1 to the user application module start executable command in your batch file.

==Parameters==
The CereStim is configured in the "CereStim" tab. The configurable parameters are:

===AppliedVoltage===

===AppliedCurrent===

===AppliedPhaseCharge===

===AppliedFrequency===

===StimulationConfigurations===

===StimulationTriggers===

===DeviceInfo===

==States==
===CereStimStimulation===

==Latency==

Contributions:Extensions

2021-07-21T13:10:13Z

Abelsten:

A framework ''Extension'' is an optional contributed plugin which can affect multiple modules. For example, various manufacturer-specific [[User Reference:Logging Input|input-device loggers]] are provided in the <code>src/contrib/Extensions</code> folder, and these can be optionally added to the BCI2000 framework for SignalSource modules, thereby giving all source modules the ability to log input from the corresponding devices. Selecting a custom Extension, and re-building your modules to include it, requires the use of CMake and a supported C++ compiler: see the [[Programming Howto:Quickstart Guide]] for a walkthrough that shows you how to recompile BCI2000 modules.

The following user extensions are available in the [[Contributions:Contents|Contributions]] section of BCI2000:

*[[Contributions:CyberGloveLogger]]: A logger extension which acquires data from CGI, CGII and CGIII Cybergloves.
*[[Contributions:DataGloveLogger]]: A logger extension which acquires data from the 5DT Data Glove Ultra.
*[[Contributions:EyetrackerLogger]]: A logger extension which acquires data from Tobii eyetrackers.
*[[Contributions:EyetrackerLoggerTobii3]]: A logger extension which acquires data from Tobii eyetrackers using SDK version 3
*[[Contributions:EyetrackerLoggerTobiiPro]]: A logger extension which acquires data from Tobii eyetrackers using Pro SDK
*[[Contributions:EyetrackerLoggerTobiiX]]: A logger extension which acquires data from Tobii Eye X eyetrackers.
*[[Contributions:GazeMonitorFilter]]: An application module filter extension which supports the EyetrackerLogger.
*[[Contributions:WiimoteLogger]]: A logger extension which acquires data from Nintendo Wii Remotes.
*[[Contributions:WebcamLogger]]: A logger extension which allows for synchronizing webcam video.
*[[Contributions:AudioExtension]]: An all purpose audio toolkit which allows for realtime multichannel audio I/O.
*[[Contributions:StimBoxFilter]]: A logger and controller for the gtec g.STIMbox.
*[[Contributions:ParallelPortFilter]]: A logger and controller for communication through parallel ports.
*[[Contributions:XsensMTwLogger]]: A logger for recording from Xsens wireless inertial measurement units.

==See also==
[[Programming Reference:EnvironmentExtension Class]]

[[Programming Tutorial:Implementing an Input Logger]][[Category:Contents]]

Contributions:XsensMTwLogger

2021-07-16T14:20:33Z

Abelsten: /* State Variables */

An BCI2000 extension that records synchronized rotational data into states, using XSens’s MTw motion tracking sensors.

[[File:XSensMTwImage.png|right|thumb| An actual image of a MTw]]

==Location==
https://{{SERVERNAME}}/svn/trunk/src/contrib/Extensions/XSensMTwLogger

==Versioning==
===Authors===
Alexander Belsten (belsten@neurotechcenter.org)

William Engelhardt (engelhardt@neurotechcenter.org)

===Version History===
*2021-07-06: Initial public release by Alexander Belsten (belsten@neurotechcenter.org)

===Source Code Revisions===
*Initial development: 6329
*Tested under: 6329
*Known to compile under: 6330
*Broken since: --

==Functional Description==
Records the X, Y, and Z positions of multiple Xsens MTw (Motion Tracking - wireless) IMUs (Inertial Measurement Units) to events.

==Integration into BCI2000==
To enable the extension in your CMake configuration, enable <tt>EXTENSIONS_XSENSMTWLOGGER=On</tt> in the Extensions folder of the CMake GUI and then generate the BCI2000 Visual Studio solution in CMake. Next, open the solution with Visual Studio and rebuild the <tt>BCI2000FrameworkSigSrcModule</tt>, and then rebuild any signal source module you want to use the extension with.
Once the extension is built into the source module, you can enable it by appending <code>--LogXsensMTw=1</code> to the source module <tt>start executable</tt> command in your batch file. Also, <code>--NumberOfMTws=1</code> needs to be appended as well. Set this equal to the exact number of MTw's you want connected.

==Installation and Set-Up==
To install the drivers for the MTw Awinda, go to their [https://www.xsens.com/software-downloads Software Downloads Page] and download the latest stable software package for your operating system for "MTw Awinda". This installs the needed drivers; now BCI2000 can connect to the MTw's. Mtw's are wireless and communicate with your PC via a USB signal receiver. This signal receiver must be plugged into your computer to record from the MTws. This receiver should be blinking in sync with the MTw's when they are recording.

==Coordinate System==
In the figure below, the orange rectangle is the MTw. Three axes are defined, the X, Y, and Z. X and Z range from -180 to 180 degrees, while Y spans from -90 to 90. All three coordinates are rotational, which means MTw’s do not directly measure translational movement.

[[File:XSensMTwCoordinateSystem.png]]

==Parameters==
===User configurable Parameters===
The motion trackers are configured in the Source tab within the MTw section.

====LogXsensMTw====
Set to 0 (uncheck) to disable the MTw logger, or 1 (checked) to enable the logger. This should be set in your batch file by appending <code>--LogXsensMTw=1</code> to the source module <tt>start executable</tt> command.

====NumberOfMTws====
The exact number of MTw's that will be connected. 1 is the default, but this number can go up to as many MTw's as you have. This parameter should be set in your batch file by appending <code>--NumberOfMTws=1</code>, just as <code>LogXsensMTw</code> is. This parameter can only be set in the batch and will not appear in the Source tab.

====MasterUpdateRate====
A default value of 80 Hz. This is the frequency that data is updated from the MTw’s to BCI2000. Below is a table provided by their [https://www.xsens.com/hubfs/Downloads/Manuals/MTw_Awinda_User_Manual.pdf MTw Awinda User Manual] of the maximum update rates relative to the number of MTw’s connected.

{| class="wikitable"
|+ '''Maximum Update Rates'''
|-
! Amount of MTw’s
! Update Rate (Hz)
|-
| 1-5
| 120
|-
| 6-9
| 100
|-
| 10
| 80
|-
| 11-20
| 60
|-
| 21-32
| 40
|}

====DataPrescaler====
A default value of 10,000,000. The most efficient prescaler is 11,930,464, but for simplicity’s sake this value is rounded. Details about what this value does is located in “Converting Back to Degrees” below.

==State Variables==

===MTw1X, MTw1Y, MTw1Z===
These states record the three rotational data values per MTw. See the “Coordinate System” section to see how X, Y, and Z are defined. If more than one MTw is connected, their label will continue to increase by 1, i.e., MTw2X, MTw3X, etc. The MTw’s connect in order of lowest serial code to highest serial code, so if multiple MTws are being recorded, MTw1 will always have the lowest serial code number. The serial codes and their respective IDs are printed in the operator log for clarity’s sake. This allows you to distinguish what MTw is recording to what state.

==Converting back to Degrees==
The MTw’s record data in units of degrees, with two of the axes going up to 180, and the other going to 90. They also record a high precision of 6 decimal places. BCI2000 records integers to states, which means that anything after the decimal point will be cut off. If the data is kept as is, this would greatly reduce the quality of the data we are collecting.

BCI2000 can record states with up to 32 bits, which is the resolution we need to record the high quality data from the MTw’s. To do this, the original data will be multiplied by the parameter <code>DataPrescaler</code>, and shifted up by 2^31.

To convert the data back into degrees, use Matlab or a similar program to
# Subtract 2^31 from every value.
# Divide the data by the <code>DataPrescaler</code>.
This should now leave you with data between -180 and 180!

==See also==
[[User Reference:Logging Input]], [[Contributions:Extensions]]

[[Category:Contributions]][[Category:Extension]]