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The thorax pane is used to display the geometry of the thorax, and any of a wide range of functions on the thorax surface. If a node on the thorax is selected, it is shown by a black patch on the surface.

What exactly is displayed in the thorax pane and how, is controlled by the various menu options available from the Thorax entry on the menu bar:

Mouse actions in the thorax pane are reflected in this pane and may also have an effect on the other ones.

The contents of the thorax pane is copied onto the clipboard by selecting Copy from the Thorax menu, or by pressing Ctrl-C while the mouse is within the thorax pane.

Surface function

The item Surface function in the thorax menu brings up a dialog window, with which you may choose the function to be displayed on the thorax surface. Available are the simulated potentials (i.e. the potentials that result from the transmembrane potentials at the heart as set by the user), the reference (i.e. measured) potentials, and the transfer function.

The most frequently used surface functions may also be activated by clicking on the corresponding button on the tool bar at the top of the thorax pane.

If surface potentials are displayed in the thorax pane, the status bar indicates the time instant for which the potentials are displayed. You may press the up and down arrow keys to in- and decrease the time by steps of milliseconds. Use the page up and page down keys for in- and decrements with steps of ten milliseconds. Also, 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. Finally, you may use the movie option to view the development of the potentials in time as a movie.

Display options

The item Display options in the Thorax menu brings up a dialog window, from which you may select how the thorax and the surface function are displayed. There are two tabs: the Geometry tab that controls the geometry options, and the Surface function tab that controls the surface function options.

Display options: Geometry

In the Geometry tab you may determine whether you want the heart, lungs, thorax and precordial electrodes to be displayed, and whether you want them to be transparent or opaque.

If a function is mapped on the thorax using a color code, the surface will always remain opaque, as a colored transparent thorax is too confusing. If you want to map a function on the thorax while being able to see through the surface, use isofunction lines only.

The heart vector and vector loop (according to the Frank Leads) for the simulated data may be displayed by choosing opaque for the corresponding items. The scale of the vector is 20 cm/mV times the scale factor of the signals in the ECGs pane. Change the size of the displayed vector by changing the scale in the ECGs pane.

Also, you may choose whether the grid and/or the nodes that make up the discretized thorax are to be displayed.

Display options: Surface function

The surface function tab allows you to determine how the function is displayed; by a color map, isofunction lines, or both. Also, you may determine whether the light effect should be active when using a color map display. The light effect gives a three-dimensional impression of the geometry of the thorax, but it also renders the colors on the surface less bright.


The item Scale in the thorax menu brings up a dialog window, by which you set the scale for the various surface functions that can be plotted on the thorax surface. This dialog window may also be started by clicking on the Scale button on the thorax tool bar.

Mouse actions in the thorax pane


You may rotate the thorax by left-mouse dragging, i.e. move the mouse while holding the left mouse button down. By rotating the mouse wheel, the thorax rotates along an axis perpendicular to the screen. If you press the shift key simultaneously, the angle by which the thorax rotates with each click of the mouse wheel becomes smaller.

You may go back to the standard frontal view by clicking on the reset orientation button on the tool bar.


A node at the thorax is selected by clicking with the right 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. If you click on the right mouse button outside the thorax, the currently selected node is deselected.

If a function is mapped on the thorax surface, the value at the selected node is displayed on the status bar of the thorax pane. If the geometry is displayed, the index of the selected node is displayed (the node index corresponds to the row in which the surface potentials for that node are saved).

In the ECGs pane you may choose to display just the (single) ECG at the selected node.