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Thorax
The thorax pane is used to display the geometry of the thorax and any of a
range of functions on its surface. You may rotate the thorax by right mouse
dragging, i.e. move the mouse while holding the right mouse button down.
You may go back to the standard frontal AP view (natural frontal view) by a
left double mouse click. If a node on the thorax is selected,
it is shown by a black dot on the surface.
The electrode positions of the selected lead system (see
leads) are shown as grey patches. In the figure below
shows the nine electrodes of the standard 12 lead system. For selecting any of
the available color-codings see options\preferences.
The contents of the thorax pane is copied onto the clipboard
by selecting Copy from the Edit menu, or by pressing <Ctrl>-C while
the mouse is within the thorax pane.
You may use the movie option to view the development in time of the
activation of the heart as ... a movie.
Surface function
Default the geometries of the heart, lung sand thorax are shown. Additionally the body
surface potentials (BSPM) a the selected time can be shown or the sensitivity map (see
transfer function).
Body surface potentials can be displayed for the:
- measured values
- simulated potentials with initial parameter settings
- simulated potentials with user adapted parameter settings
Note: The sensitivity map can only be shown when a probe
position is selected on the heart. In case no valid probe postion is determined
no surface function is displayed on the thorax. A notification is also given in the statusbar.
When viewing a BSPM you may press the left and right arrow keys to step forward/backward in
time. Alternatively, you may click in the membrane or in the
ECGs pane to select the time instant for which you wish the
potentials to be displayed.
Show/Hide lungs
The lungs can be hidden by pressing the
button and shown again by pressing the
button.
Scale
The amplitude scale may be changed by scrolling with the mouse wheel or by the by the
arrow up and arrow down keys. The cross plane may also be moved by the
arrow up and arrow down keys.
The arrow keys only work after the pane has
obtained the "focus" by a mouse click in the thorax pane.
Movie
Finally, you may use the movie option to view the development of the potentials in time
as a movie. The movie may be started and stopped by the play/stop button.
The direction and speed of the movie may be changed in the options/movie dialog
(see below). The speed of the movie is experessed in ms/s, i.e. the number of
"ECG" ms played in 1 second. The movie can also be paused by pressing the
pause button
The movie loops through the time starting at the beginning of the shown ECG signals up
to the end of the shown signals (see leads). When the
depolarization times are shown on the heart surface the movie shows the progression of
the activation wave over the heart surface, both in the thorax pane and the heart pane.
Mouse actions
select thorax node
A node at the thorax is selected by clicking with the left mouse button on the thorax
surface. The node nearest to the "click" is selected, as shown by a black patch on the
surface. Only one node may be selected at a time.
If you select another node, the previous one is deselected. In the
leads pane you may choose to display just the ECG at the selected
node (single lead). The selected node is only shown when a single lead
ECG is shown in the leads pane or when the
contribution map is selected in the heart pane
Display options
If you want to map a function on the thorax while also seeing through its
surface, use isofunction lines only.
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