Acquiring Data and Playing Back Trials

Before acquiring data, ODIN must be connected to the system hardware. Instructions for connecting to the hardware can be found here.

1 Live Mode and Recording Data

To select the “Live” mode, click on the button “Live”. If the button “Live” is blue then the “Live” mode is selected. If the Live button is not available, ODIN is not connected to any hardware.

Figure 1

After clicking on the “Live” button, the CODA Units start streaming and the marker positions and other device data are automatically displayed in the Text and 3D views. The streaming can be paused and re-started by clicking on the “Stop” and the “Play” buttons.

Note: graphs are not updated in real-time live mode except the live analogue data graph – see Section 3.5.

Note: the play button is automatically selected when you switch from the “Play” mode to the “Live” mode.

Before starting data acquisition, a Subject ID must be entered in the Trial list, in the ‘ambient trial’ on the bottom row. Note that the acquisition date and time, and a repetition label (“RepLabel”) are filled-in automatically, so the Subject ID doesn’t need to include a date code. Note also that you can customize the Trials List to include extra fields for comments, trial conditions, etc. – see section 3.3.6.1. You can also change the repetition label sequence number by typing a new number into the RepLabel field. This number is incremented automatically for subsequent acquisitions.

To start the acquisition, press the red “Record” button. The play button will become non-selectable automatically. To stop the acquisition before the programmed time limit (if any), press the “Stop” button.

If any 3D views are active during acquisition, they will display time elapsed and time remaining information in the top left corner:

Figure 2

At the end of an acquisition, the trial data will be saved automatically into the database and the Marker Visibility Summary may be displayed automatically (optional – see section 3.6). Then any defined calculations will be run. The Subject ID, Date & Time, RepLabel are the primary reference keys into the trials database. Just after having clicked on the “Stop”, the message “Saving Acquisition” will appear. Once the message disappears a new capture can be started. NOTE: If the “Subject ID” field is not filled then a warning message will appear just after clicking on the “Record” button and the acquisition will not start.

Figure 3

2 Playing Back Your Trial

Once all your experiments have been captured, press the “Playback” button to access the recorded data. The control panel will change slightly. The “play backward”, “previous frame” and “next frame” buttons replace the “record” button.

Figure 4

All the opened trials of the current session are visible in list “Trial List” at the bottom left of the principal screen (red rectangle). Simply click on the desire trial to open it. All the views will be automatically updated to show data from the selected file when a new trial is chosen. The control of the playback can be done either through the control panel or through a graph display.

You can make the animation on a 3D view of a data file move either forwards or backwards (in time). As the stick figure moves along, the cursor on any graphs will also move along, giving an accurate indication of the time in seconds at the current position of the stick figure.

To animate the stick figure continuously forwards in time:

Choose Play from the “Utilities” menu, or use simultaneously the “CTRL + SHIFT + P” keys, or click on the play button on the toolbar , or click anywhere on the empty grey area near the transport region and it will activate the playback keyboard shortcut. Press up arrow key to toggle, play and stop.

To animate the stick figure continuously in reverse time:

Choose Back from the “Utilities” menu, or use simultaneously the “CTRL + SHIFT + B” keys, or click the left arrow on the toolbar . Press down arrow key to toggle play backward and stop. The speed of the animation can be controlled by using the “+” or “-” buttons.

To stop a moving stick figure:

Choose Stop from the “Utilities” menu, or press simultaneously the “CTRL + SHIFT + S” keys, or click on the square stop button on the toolbar .

To make the stick figure move forward by step:

Choose Step Forwards from the “Utilities” menu, or press simultaneously the “CTRL + SHIFT + Close Bracket” keys, or choose the forward step button from the toolbar . Press the right arrow key to move forward by one step.

To make the stick figure move back by step:

Choose Step Backwards from the “Utilities” menu, or press the simultaneously the “CTRL + SHIFT + Open Bracket” keys, or choose the backward step button from the toolbar . Press the left arrow key to move backward by one step.

Playback can also be controlled by ‘clicking and dragging’ a graph cursor. The cursor in any displayed graph can be used for this purpose. If no graph is displayed in the current layout, then this control function is not available.

To control the animation through the playback cursor, simply select and drag it to the desired location. As the cursor is moved, any 3D views on the screen will update accordingly.

To zoom-in or zoom-out

Press the SHIFT key and select the time period where you want to zoom-in by clicking and dragging the vertical bar at the desired position. The time period will be then selected in turquoise-blue through two vertical bars. Double click inside the selected area to zoom in. To zoom-out, simply press the spacebar. The above procedure can be repeated in an already zoomed area to produce successively more zoomed-in views. Pressing the spacebar allows the user to go one step backward.

3 Using Live Analogue Data Graph Views

Live views of analogue data are a special type of graph view, introduced in ODIN 1.05, to allow users to track analogue data while in live-monitoring or acquisition mode.

This section shows you how to configure a real-time graph for analogue data:

a) Open the protocol you wish to work within, and connect to RTServer on the ActiveHub/CodaHub.

b) On the protocol tree, expand the “ViewDefinitions” node to view “Live Graphs” and right-click on the node. This will show you the following pop-up menu:

c) Select “Add New” to create a new live graph definition:

Figure 5

d) Populate the “Name” textbox and click on the “+” button under the “All plots” section to add a new plot. You will now see a new pop-up dialogue box which will allow you to add channels to your graph:

Figure 6

e) Select the “+” button to add a channel to your plot. From the empty row that appears, select “Analogue” for the Group column. Select one of the available channel names from the Channel column drop-down list. Select “Value” from the drop-down list on the Dim column. Select “value” from the drop-down list on the Field column. Choose a plot colour by double-clicking on the Colour column and selecting a colour from the palette. You can add multiple channels to your plot. Click on OK to close this window and get back to the Live graph definition dialogue:

Figure 7

f) The live graph definition dialogue has now been populated with the newly created plot. Each plot can contain multiple channels, while each live graph can contain multiple plots. Notice that the Ordinate Axis section is populated with axis information for each plot that you add. You can configure this similarly to playback-graphs. Selecting the “Auto” options under Type will automatically scale the ordinate axis on every screen-refresh. Alternatively, you can select “Manual” for the Type column and specify maximum and minimum ranges on the Y-axis. Click on the OK button to save the definition.

Figure 8

g) The newly added live graph definition will now appear on the protocol tree. Select a pane from the current layout and launch the live graph view into the pane using the right-click menu “Launch” option, or by double-clicking on the definition itself:

Figure 9

h) Switch to “Live Mode” and select “Play” from the transport bar to start monitoring live data from RTServer or “Record” to begin acquiring data. You should now see an animated graph showing real-time data from the CodaHub/ActiveHub:

Figure 10

i) Here is an example of a live graph with multiple channels with an offset on the y-axis:

Figure 11

j) It is important to keep in mind that live graph data may contain aliasing artefacts. This is because live graphs display data sampled at 25 Hz. The data displayed by these graphs is not filtered or averaged. Configuration of the analogue board to acquire at a specific sampling rate has no effect on live graphs.

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