Page History: OpenEEG Signal Element
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Page Revision: 2014/12/28 06:36
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OpenEEG Signal Element
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| Info |
| Category: |
Signal Acquisition |
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AddIn: |
Signal Processing |
| Creator: |
OkazoLab Team |
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Scope: |
Global |
| Owns Snippets: |
no |
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Usage: |
background |
Element actions aligned with different epochs of the parent event
| Epoch | Actions |
|---|
| Experiment Onset | The element starts data acquisition and buffering. |
| Control Loop step | The element buffers newly received samples |
| Experiment Offset | The element stops data acquisition and buffering. |
Properties
Generic Properties
| Name | Description | Constraints | Value Type | Upon Runtime Change |
|---|
| Port Settings |
| Port Name | Defines the name of serial port that is connected to EEG hardware | | String | |
| Baud Rate | Defines the serial baud rate (samples per second) of the serial port | | Int32 |
| Stop Bits | Defines the number of stopbits per each transferred byte | | Int32 |
| Parity | Defines the parity-checking protocol for the port | | string |
| Data Bits Number | Defines the number of data bits in each transferred byte | | Int32 |
+=== Properties inherited from the base signal provider element ===
Inherited properties of the Signal Provider Element
| Channel Configuration |
| Selected Channels | Defines what signal channels are selected for acquisition within EventIDE. Selected channels are registered in the EventIDE signal pool at runtime and become available for the signal analysis elements. | | IList |
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| Selected Channel Count | Indicates how many signal channels are currently selected for acquisition. | | Int32 |
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| Total Channel Count | Indicates how many signal channels are available for acquisition in the total. | | Int32 |
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| Buffer Size | Defines the size (in samples) of a circular buffer that stores incoming signal data. | | Int32 |
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| Signal Generator |
| Signal Source | Defines a source for the signal. The emulated rhythmes can be used for offline validation of the chosen analysis settings | | enum |
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| Emulated Sampling Rate | Defines the emulation sampling rate (samples per second), when data is generated or streamed from a file. | | Int32 |
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| Primary Frequency | Defines the frequency of the primary rhythm in the generated signal, in Hz. Assign the zero to exclude the primary frequency from the generated signal. | | Double |
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| Secondary Frequency | Defines the frequency of the secondary rhythm in the generated signal, in Hz. The secondary frequency magnitude is a half of the primary frequency magnitude. Assign the zero to exclude the secondary frequency from the generated signal. | | Double |
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| Noise Level | Defines the noise level (in % to the norm magnitude of the primary frequency). The noise is added to the generated signal. Assign the zero the exclude the noise from the generated signal. | | Double |
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| External Datafile | Opens the dialog for selecting a data file containing a stream of double numbers representing a signal. If a file name without a path is defined, the data file will be picked up in the location of the experiment file. | | String |
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+=== Properties inherited from clElement ===
Inherited properties of clElement
| Name | Description | Constraints | Value Type | Upon Change |
|---|
| Control |
| Is Enabled | If set to false the element is completely omitted when the experiment is run. | | Boolean |
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| Title | Title of the element. | | String |
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The element allows a real-time signal acquisition with any EEG hardware supporting the
OpenEEG protocol Description
The OpenEEG Signal element reads an EEG signal conveyed directly from EEG hardware via the OpenEEG protocol. As an experiment starts, the element begins receiving data and buffering samples into circular buffers, maintained by EventIDE (the buffers can collect data from multiple signal acquisition elements). The signal processing elements, e.g.
Signal Analyzer element can be then used to monitor and analyze the buffered signals at runtime. Fast buffering and processing time in EventIDE (down to 1ms) allows instant detection of signal characteristics and, subsequently, various forms of signal-based feedback control in experiment.
Practical Use
- Add a new OpenEEG Signal element to any event in your experiment (the element is global and works from the start to the end of experiment).
- Select the added element to browse its properties in the Property panel.
- Enter the system name of the serial port connected to your EEG hardware, e.g. 'COM1', 'COM2', etc.
- Adjust the parameters of the serial port transmission, if necessary.
- Select the channels for acquisition and buffering within EventIDE via the Selected channels property.
- Once the channels are selected, you can access them with by of the signal processing elements.
Notes
- In order to use OpenEEG element, you should have EEG hardware supporting the OpenEEG protocol. The hardware must be connected to a serial port of your computer and be operational both at run-time and design-time (when the acquisition channels are selected).