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Unemap Manual
UnEMAP : Electrocardiac Mapping System
User Manual May 1994:
This document is split into three sections: the Tutorial Section, which consists of an example session using Emap, the Reference Section, which consists of a feature by feature description of the software, and finally a section on the Configuration File Format
You can also inspect the Table of Contents, and the Index as well.
TUTORIAL
1.1 Starting
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Start a session by typing unemap.
The main menu appears in Figure 1.
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The colour specification file, Emap, can be edited and colours redefined. |
Figure 1. The main menu
1.2 Rig Set Up
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Select Mapping from the main menu by clicking once with the mouse. The electrode positions for the default configuration are then shown in the lower pane of the Mapping window. To specify a different rig configuration select the Read configuration option from the File menu. A dialog box will appear from which the desired configuration can be chosen. The Mapping window for tutorial.cnfg (which may be the default configuration) is shown in Figure 2. The top pane contains the auxiliary inputs. The bottom pane shows the heart electrodes
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See section 2.4.1.2 for configuration creation and modification.
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Figure 2. The Mapping window
1.3 Data Acquisition
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Select Acquisition from the main menu. The Acquisition window is shown in Figure 3. Click Experiment. You will be prompted for a directory to put the data files in. Click Acquire in the Acquisition menu . The specified data will be acquired and you will be prompted for a file to save it to. Close the Acquisition window.
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The time segment over which the measurements are taken is represented by the horizontal line. The length of time segment is altered by dragging the right hand end with the mouse. The number above the line is the length of the time segment in seconds. The acquisition time is the time when Acquire was clicked. The acquisition time can be changed by dragging the marker which is below the line. The number shown below the line is the time before the acquisition time that the time segment started.
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Figure 3. The Acquisition window
1.4 Data Analysis
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Open the Analysis window by selecting Analysis from the Main Menu. To read in signal data choose the Read signal option from the File menu. The name of the signal file that was created in data acquisition will appear in the file menu. Select this file by clicking once on the file name and then once on OK or by double-clicking on the file name. The data will be similar to that shown in Figure 4. The signal from each electrode appears in the bottom pane of the Analysis window. The first signal in the pane is the current signal.
The current signal is highlighted and is shown in the top pane of the Analysis window and both panes of the Signal window (Figure 5).
The current signal can be accepted or rejected by clicking Accept or Reject from the top menu bar of the Analysis window.
Signals that have been rejected are coloured orange.
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The displayed order of signals in the lower pane of the Analysis window can be either arranged according to channel number or event time. The signals can be displayed separately or all the signals can be Overlapped. If Separate display is chosen each signals appears in the Analysis window on a separate graph Electrodes can be grouped as regions. Signals from different regions can be viewed separately. The possible regions for each rig are given in the last menu. A shorter interval can be selected for analysis using the yellow box in the top pane of the Analysis window. This interval is shown in the lower pane of the Analysis window and the top pane of the Signal window. This interval can be saved using Save interval from the File menu.
The colour settings file, Emap, can be edited and colours changed.
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Figure 4. The Analysis window
Figure 5. The Signal window
1.5 Potential Map
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A map of potential can be drawn by selecting Potential from Map in the Analysis menu bar. The time for which the map is drawn is specified by the vertical red line in the top pane of the Analysis window. This time can be altered by dragging it to the desired time with the mouse. A dialog box appears. Click Accept all. The electrode configuration in the Mapping window is replaced by a Potential Map (Figure 6). The top pane in this window now shows the colour scale. Click OK for the message that appears describing how good the fit is. If the time at which the Potential map is required is altered, the map should be redrawn by selecting Potential again.
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For a sock there are two ways of drawing the map - Hammer projection or Polar projection. For the Hammer projection the left and right hand boundaries correspond to a cut down the middle of the right ventricle. For the Polar projection the apex is at the center and the heart is viewed from the apex end. The current projection is shown on the Mapping menu and can be changed by clicking and selecting.
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Figure 6. A potential map
1.6 Activation Times
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To calculate the times of activation, click Calculate from the Signal menu. There are two ways of calculating the activation times - Interval and Threshold. For Interval, the search interval defined in the top pane of the Analysis window can be split into 'beats'. This is done by clicking the increase/decrease in the top menu bar of the Signal window. One Activation time is calculated for each beat. If Threshold is selected, a threshold gradient (calculated as a percentage of the maximum gradient) and an event separation time must also be specified. The activation times appear on the signals in the Analysis window as green vertical lines (see Figure 7). Activation times are not calculated for rejected signals. The activation times of the current signal can be altered by dragging the activation lines in the lower pane of the Signal window to the desired time. This change is reflected in all other signal panes. The event times can be saved by choosing the Save event times from the File menu in the Analysis window. Dialog boxes will request which events are to be saved and a file name to which they are saved.
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The Previous, Next, Accept and Reject options in the lower menu bar of the Signal window operate analogously to those in the Analysis menu bar but apply to the activation times of the current signal. If Device order is selected the Next/Previous command moves through all the signals showing the same 'beat' before moving to the Next/Previous beat. If Beat order is selected the Next/Previous commands move through all the beats for one signal before moving to the Next/Previous signal.
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Figure 7. Activation time markers
1.7 Activation Map
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An Activation time map can be drawn by selecting Activation under Map in the Analysis menu bar. The signals which are to be used in the map are selected with the dialog box that appears. The map is shown in the bottom pane of the Mapping window (see Figure 8). Click OK for the dialog box appears showing information on map fit.
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Features of the map may be changed by clicking Map in the Mapping window. See section 2.4.2.1.
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Figure 8. An activation map
1.8 Finishing
The session is ended by clicking Close in the main menu.
REFERENCE
2.1 ACQUISITION WINDOW
Experiment sets the zero time for time measurement and allows the user to select a directory to save data to. If Acquire is selected, the name of a file to record the signal data in is requested. Monitoring enables signals from electrodes to be viewed, with the use of Page, while the experiment is running (this feature has not yet been implemented). Calibration is possible if the experiment has not been started.
The length of the acquisition interval can be altered by dragging the start and finish times with the mouse.
2.2 ANALYSIS WINDOW
2.2.1 Top Pane
The top pane of the analysis window shows the currently selected signal. The name of the input device is shown on the left hand side of the pane. The vertical yellow lines of the analysis interval can be dragged along the pane with the mouse - the box determines the signal interval shown in the lower Analysis pane and the top Signal pane. The analysis interval in the Analysis window can be dragged to cover other times with the mouse.
The data for the analysis interval for all signals can be saved by choosing Save Interval in the File menu.
The red vertical line indicates the time for which the potential map would be drawn. Clicking on Baseline adjusts the offset for each signal so that the potential at this time is zero.
The potential range for the current signal can be altered by holding down the mouse on the vertical axis in the lower pane of the Signal window and dragging the yellow line that appears. If Range in the Analysis window is then selected, this new range will be used for all signals.
2.2.2 Acceping/Rejecting Signals
Electrode signals can be Accepted/Rejected using the top menu bar. All signals in the lower pane can be viewed using Next/Previous selection. Clicking Next or Previous when the current signal is undecided will cause the signal to be accepted.
2.2.3 Map Menu
Clicking Potential under Map causes a potential map to be drawn in the Mapping window.
An activation map can be drawn, if event times have been read or calculated, by selecting Activation under Map in the analysis window. The activation map will be drawn for the current 'beat'. Rejected activation markers will not be used when drawing the activation map.
The Gradient option has not yet been implemented.
2.2.4 File Menu
To read in signal data choose the Read signal option from the File menu. A file selection box will appear and the signal file required can be selected by clicking once on the file name then once on OK or by double-clicking on the file name. A part of the current signal interval can be saved by adjusting the yellow box in the top pane so that it encloses the desired sub-interval and selecting Save Interval.
Event times can be calculated or read from a file. To read event times from a data file choose the Read event time from the file menu. A dialogue box will request a file name. If the event times have been calculated they can be saved to a file using the Save event times option.
2.2.5 Bottom Pane
The displayed order of signals in the lower pane of the Analysis window can be either arranged according to Channel number or Event time.
The signals can be displayed separately or all the signals can be Overlapped. If Separate display is chosen each signal appears in the Analysis window on a separate graph.
Electrodes can be grouped in regions. Different regions can be selected to look at different groups of signals. The possible regions for each rig are named in the last menu.
2.3 SIGNAL WINDOW
The Signal window is used for determining the activation times for the electrode signals. There are two ways of calculating the activation times - Interval and Threshold. The calculated activation times can then be corrected by the user.
2.3.1 Search Interval
The yellow box in the top pane of the Signal shows the interval for which activation times will be calculated.
For the Interval option, the search interval can be split into a maximum of nine 'beats'. This is done by clicking the increase/decrease arrows. The active beat is indicated by a solid white box in the top pane and is shown enlarged in the bottom pane. The active beat can be changed by clicking the mouse in one of the other beats.
For the Threshold option, the solid white box will initially be the same size as the search interval. As for the Interval option, the interval in the solid white box is shown in the lower pane. Unlike the Interval option, the ends of the white box can be adjusted, separately from the search interval, using the mouse. If an activation marker in the upper pane which is not within the white box is selected, the white box will be centered on it.
2.3.2 Calculating Activation Times
The activation times, for the signals that are not rejected, are computed if Calculate is selected. The way in which these are computed depends on whether Interval or Threshold is being used.
If Interval is specified, then one activation time is calculated for each beat. The activation time is the time at which the signal gradient/slope is greatest.
For the Threshold option, activation times are chosen so that the gradient is greater than the specified percentage of the maximum for the interval and so that the separation between activation times is greater than the specified minimum. Activation times can be calculated for all signals that are not rejected using Calculate all, or just for the current signal with Calculate current.
The activation markers appear as vertical green lines in the Signal window and bottom pane of the the Analysis window. The delay times for the markers of the current signal are shown in the upper pane. The delay time for the current activation marker is shown in the lower pane. The activation times can be altered by dragging the markers in the bottom pane of the Signal window with the mouse. For the Threshold option, markers can be added or deleted using the right mouse button.
2.3.3 Datum time
The datum time is the time from which activation delays are measured. The datum time is common to all signals and is shown as a white line in the bottom pane of the Signal and Analysis windows. The datum can be moved with the mouse and this will change the activation times for all signals. During the calculation of activation times, the datum can be Automatic or Fixed. If activation times are calculated with Automatic, the datum time will be shifted to be the earliest calculated activation time. If activation times are calculated with Fixed, the datum will not be changed.
2.3.4 Accepting/Rejecting Activation Times
The Previous, Next, Accept and Reject options in the lower menu bar apply to the activation times. Activation times can be Accepted/Rejected using the menu bar. If Device order is selected, Next/Previous moves through all the signals showing the same 'beat' before moving to the next/previous beat. If Beat order is selected, Next/Previous moves through all the beats for one signal before moving to the next/previous signal.
Clicking Next or Previous when the current activation time is undecided will cause the activation time to be accepted.
2.4 MAPPING WINDOW
The menu bar for the mapping window has different entries depending on whether it is associated with analysis or acquisition.
2.4.1 When Acquiring Data
The upper pane is used for displaying the auxiliary inputs.
2.4.1.1 Rig Set Up
Clicking on Set up brings up a dialog box for creating new electrode layouts. The Rig may be a sock (whole heart) or a patch (plaque). The number of Rows, Columns, Regions and Auxiliary inputs in the rig can be altered with the increase/decrease arrows. Set up on the dialog box will cause the new configuration to be created and displayed.
2.4.1.2 Modify
This feature has not yet been implemented.
2.4.1.3 Page
This feature has not yet been implemented.
2.4.1.4 File
The configuration of a rig can be saved to a file or read from a file using this menu. The default option in this menu makes the default configuration (automatically read in when emap starts) the same as the current configuration.
2.4.1.5 Map Projection
For socks the map projection can either be Hammer or Polar. The Hammer projection has the left and right hand boundaries corresponding to a cut down the middle of the right ventricle. The Polar projection has the apex of the heart at the center and the heart viewed from the apex end.
2.4.2 When Analysing Data
The upper pane is used for displaying the colour scale. It can be altered by dragging the vertical reference lines to the desired position. The Set up button is replaced by a Map button which is used for setting mapping display options (see below). The Modify and Page buttons are replaced by an Animate button. The Animate button shows the activation wave moving throught the rig.
2.4.2.1 Mapping Display Options
Selection of Map brings up a dialog box for specifying map display options.
If Colour map is deactivated the set up of the rig is shown in the mapping window. If a map has previously been drawn selection of Colour map will show the Activation or Potential map.
Contours can be drawn on the Activation or Potential maps. The number of contours is altered with the increase and decrease arrows.
Electrodes on the map can be shown as a Value, Name or Channel by selecting one of these options from the menu.
Value can be shown if activation time or potential are being mapped.
Name will show the electrodes names;.
Channel shows the channel number for the electrode.
Fibres can be displayed with Fine, Medium or Coarse spacing.
Landmarks such as arteries can also be displayed.
CONFIGURATION FILE FORMAT
This section specifies the format for the configuration (.cnfg) files. Values that need to be entered by the user are enclosed in angle brackets.
On the first line are the rig type (sock or patch) and the name of the rig separated by a colon -
(rig type) : (name)
On the following line are rig type dependent properties.
a) sock. Specify the focus to be used for the Hammer projection as -
focus for Hammer projection : (value)
b) patch. No rig type dependent properties
There may be a number of mapping regions eg. the plunger levels for a patch or the epicardium and the endocardium for the whole heart. A separate map is drawn for each region ie. the region geometries are independent/unrelated. For each region there is a region heading line -
region : (region name)
followed by a list of inputs for the region. For each input the first line is -
(input type) : (input name)
The input type is either electrode or auxiliary. The second line for an input is -
channel : (channel number)
For an electrode there is an additional line specifying the position. This depends on the rig type.
a) sock.
position : x = (value), y = (value), z = (value)
b) patch.
position : x = (value), y = (value)
The line following the last input in the last region is the heading for the pages section. It is simply -
pages
For each page there is a page name and a list of input names in the following form -
(page name) : (input_name) (, ...)