6.2. Selections

In the signal-view-plugins, libRASCH supports the concept of selections. Selections are a subset of events which have one common property. For example you can select all heart beats which belongs to the same template (i.e. all heart beats with similar morphology) or you can select all ventricular beats.

In these selctions, you can step back and forth with the following keys:

• 'space bar': go to the next item in the selection

• 'b': go to the previous item in the selection

When a selection is "active", then the number of selected events and the current position in the selection is shown in the signal view in the lower right corner. The figure "12/456" means that you are currently at the 12th event from 456 selected events. For example the numbers inside the red circle in Figure 6-5.

Selections are implemented in the signal-specific view plugins. Therefore the type of selections will differ from signal to signal but the concept will be always the same independent of the signal type. (Because at the moment there are not so much signal specific view plugins, the examples shown here are all for ECG's.)

Figure 6-2 shows the context menu which pops up when pressing the right mouse button inside an ecg view. The main context menu has three entries: (1) General Options, (2) Channel Options and (3) ecg. The first two entries are available in all view-plugins and will be described in Chapter 8. The third entry (ecg) is only available in ecg views. The ecg entry has two sub entries: (1) sort and (2) templates. Figure 6-2 shows the sub menu of the sort entry and Figure 6-3 shows the sub menu of the template entry.

When you are interested in specific beat types (e.g. all ventricular beats or all artifacts) then you have to choose the wanted beat type from the sort menu. If you are interested in a specific template, then you have to choose the template from the template menu. After the selection of the selection criteria, the first beat in the selection is shown in the signal window. The selection is sorted chronological.