'\" t .TH WVIEW 1 "1 August 2002" "WFDB 10.2.7" "WFDB Applications Guide" .SH NAME wview \- WFDB browser for MS Windows .SH SYNOPSIS \fBwview\fR .br \fBwview\fR \fIrecord\fR .br \fBwview\fR \fIrecord annotator\fR .br \fBwview\fR \fIrecord annotator start-time\fR .br \fBwview\fR [\fIdrive:\fR][\fIpath\fR]\fIrecord\fB.hea\fR .SH DESCRIPTION .PP Note: \fBwview\fR will soon be retired in favor of \fBgtkwave\fR(1). .PP This program reads one or more signal files and an annotation file (if one is available), and displays the signals with annotations on a PC running MS Windows 3.1 (or later). To run it, either select the \fBwview\fR icon from the appropriate Start menu or Program Manager group (usually `Applications'), select a WFDB `header' file (a file named with the suffix `.hea') from Windows Explorer or File Manager, or enter one of the \fBwview\fR command lines listed above (under `Synopsis') in the \fBRun...\fR window of the Start menu or the Program Manager's \fBFile\fR menu. The first two of these methods work only if \fBwview\fR has been installed as described below, under `Installation'; use the \fBRun...\fR method if you have not performed the full installation procedure. If MS Windows is not running, you may start it and launch \fBwview\fR from the MS-DOS prompt by typing \fBwin wview\fR (this command may also include \fIrecord\fR, \fIannotator\fR and \fIstart-time\fR options as shown above). Refer to Microsoft's \fIWindows User's Guide\fR for general information about starting and using MS Windows. .PP The current version of \fBwview\fR is an alpha release. A few of the controls are not implemented, and appear as inactive (greyed) menu items. In comparison with other available software for viewing annotated WFDB records, \fBwview\fR's capabilities lie somewhere between those of \fBview\fR(1) (for MS-DOS) and \fBwave\fR(1) (for the X Window System). \fBwview\fR can do anything that \fBview\fR can do, and much more, but \fBview\fR is likely to be substantially faster than \fBwview\fR on older PCs that do not have 32-bit CPUs with numeric coprocessors and MS Windows accelerated graphics cards. \fBwview\fR has most of the display capabilities of \fBwave\fR with the exception of `scope' windows, but it lacks \fBwave\fR's capabilities for annotation editing and control of external analysis programs, as well as a variety of less important features. .SS Choosing Files to View .PP The \fBChoose Inputs\fR dialog usually appears when you start \fBwview\fR. It allows you to select a database \fIrecord\fR to view. If you start \fBwview\fR using a command line, or by selecting a WFDB `header' file from the File Manager, \fBwview\fR opens the record immediately without showing the \fBChoose Inputs\fR dialog. If you supply a record name but omit the annotator name, \fBwview\fR attempts to find the reference (\fBatr\fR) annotations. At any time, you may pop up the \fBChoose Inputs\fR dialog by selecting \fBOpen...\fR from the \fBFile\fR menu, in order to change the record or annotator names, or the \fIWFDB environment\fR (the \fIWFDB path\fR and the \fIWFDB calibration file\fR). .PP To select sets of signals and annotations to view, fill in the \fBRecord name:\fR field (up to 8 characters), and the \fBAnnotator name:\fR field (up to 3 characters). Leave the \fIAnnotator name:\fR field empty if the record is unannotated, or if you do not wish to view annotations. Although the WFDB environment may be changed within the \fBChoose Inputs\fR dialog, note that the effects of any such changes are limited to the current session of the WFDB (other WFDB applications and future \fBwview\fR sessions are unaffected). .PP The \fIWFDB path\fR is a list of directories that are searched when you specify a record or annotator name. The WFDB path is usually initialized by setting the MS-DOS environment variable \fBWFDB\fR before starting MS Windows, using the MS-DOS batch file \fBsetwfdb.bat\fR (see \fIsetwfdb\fR(1)). If a WFDB `header' file was selected (either from the File Manager or from the command line), the optional \fIdrive:path\fR component of the file name, if present, is inserted at the beginning of the WFDB path (but after the current directory, if the WFDB path begins with the current directory or has not been initialized). .PP The \fIWFDB calibration file\fR is a text file containing information about the relative scales of many different types of signals (see \fBwfdbcal\fR(5)). The WFDB calibration file is usually specified by setting the MS-DOS environment variable \fBWFDBCAL\fR; as for the WFDB path, this is usually performed using \fBsetwfdb.bat\fR before starting MS Windows. Do not include a drive specification or path information in the name of the WFDB calibration file unless the file cannot be found in any of the directories named in the WFDB path. .SS Browsing a Record .PP Use the scrollbar at the bottom of the window to move in either direction through the record. If you click on the scrollbar arrows, the display scrolls by 1 second at a time in the indicated direction. Clicking in the rectangles beside the ``thumb'' of the scrollbar scrolls the display by the width of the window. You may also drag the ``thumb'' to move to any desired location. .PP Keyboard commands can also perform these functions and others: .br .TS center; r l. back 1 second forward 1 second back 1 screenful forward 1 screenful back to beginning forward to end search forward (see below) search backward (see below) zoom in (increase time scale) zoom out (decrease time scale) + increase signal amplitude - decrease signal amplitude .TE .PP You may also enter a desired time in the \fBRecenter at\fR field of the \fBFind\fR window (accessible from the \fBEdit\fR menu). \fBwview\fR redraws the display centered on the specified time. .PP The times shown in the lower corners of the signal window usually indicate elapsed time from the beginning of the record in hours, minutes, and seconds (hours are omitted if the elapsed time is less than one hour). If the times are shown enclosed in square brackets, they indicate the actual time of day (and possibly the date) when the signals shown were recorded, determined by reference to the base time and date recorded in the header file for the record. .SS Options .PP Use the \fBOptions\fR menu to set display and printing options. The \fBView Options...\fR dialog allows you to choose display scales, turn the grid on and off, and select options for annotation and signal display. The \fBPrint Options...\fR dialog is very similar, but its options apply to printed output only. (The \fBPrint Options...\fR dialog may also be accessed via the \fBOptions...\fR button in the \fBPrint...\fR dialog, which may be opened from the \fBFile\fR menu.) .PP Select \fBUse default scales and options\fR from \fBView Options...\fR to reset all display options to their initial values. In \fBPrint Options...\fR, select \fBUse display scales and options\fR to set the printing options to match those you have chosen for display. .PP If displayed or printed, the \fBgrid\fR marks 200 ms intervals horizontally, and 0.5 mV intervals vertically. (For signals not dimensioned in units of mV, the WFDB calibration file specifies the scaling factor between the physical units of the signal and mV.) At the default scales, the grid intervals should measure 5 mm on your screen or printed output, corresponding to the standard ECG display scales of 25 mm/s and 10 mm/mV. (If this is not the case, click on \fBCalibrate...\fR and follow the instructions on-screen to make appropriate adjustments for your hardware.) .PP \fBMarker bars\fR, if displayed or printed, show the exact locations of each annotation. Note that policies for placement of ECG annotations may vary between records (for example, in the MIT-BIH Arrhythmia Database, QRS annotations are placed at the R-wave peak, but in the AHA Database, these annotations are placed at the PQ junction). .PP Normally, \fBwview\fR shows only the mnemonic corresponding to the primary annotation type (the \fBanntyp\fR field) of each annotation. Exceptions include \fBRHYTHM\fR annotations (for which the rhythm, encoded in the \fBaux\fR field of the annotation, is shown); \fBNOISE\fR annotations, for which signal quality data encoded in the \fBsubtyp\fR field are shown); and \fBSTCH\fR, \fBTCH\fR, and \fBNOTE\fR annotations (for which the contents of the \fBaux\fR field are shown). To make it easier to identify these exceptions, \fBRHYTHM\fR annotations appear below the level of ordinary annotations, and the others appear above the level of ordinary annotations. The representation matches that used in the \fIMIT-BIH Arrhythmia Database Directory\fR and other directories, which contain complete lists of the mnemonics used in each database. .PP By selecting the appropriate items from \fBView Options...\fR or \fBPrint Options...\fR, you can view or print the contents of the optional annotation fields (\fBsubtyp\fR, \fBchan\fR, \fBnum\fR, and \fBaux\fR, shown from top to bottom in that order if two or more are selected). See the \fIWFDB Programmer's Guide\fR for further information about optional annotation fields. .PP \fBSignal baselines\fR, if selected, are displayed or printed only for signals for which absolute levels are significant, such as blood pressure. Such signals are referred to as DC-coupled signals, since they must be digitized without being passed through high-pass filters in order to preserve absolute levels. In signals such as ECGs, only variations in level, rather than absolute levels are significant. These AC-coupled signals are high-pass filtered before digitization, in order to remove any DC component, so that the gain can be chosen optimally for the range of variation in the signal. By default, \fBsignal names\fR appear at the left margin slightly above each signal; deselect \fBSignal names\fR to suppress this output. The header file for each record specifies signal names, and which signals are DC-coupled; see the \fIWFDB Programmer's Guide\fR for further information. .SS Searching for Annotations .PP Select \fBFind...\fR from the \fBEdit\fR menu to bring up the \fBFind\fR dialog. Enter an annotation mnemonic (e.g., \fBV\fR) in the \fBSearch forward\fR or \fBSearch backward\fR field. Click on the radio button to the left of the chosen search direction, then click on \fBOK\fR. \fBwview\fR redraws the signals, centered on the next annotation of the specified type that was not visible in the previous screenful. If the search is unsuccessful, the \fBFind\fR window remains visible, so that you can modify the search criteria. .PP In addition to standard annotation mnemonics (listed in the \fIWFDB Programmer's Guide\fR), you may enter signal quality strings (as displayed by \fIwview\fR for \fBNOISE\fR annotations), or \fBaux\fR strings (as displayed for \fBRHYTHM\fR, ST and T change, and \fBNOTE\fR annotations). In short, you may search for any string that \fBwview\fR uses when drawing annotations. When specifying \fBaux\fR strings, a prefix is sufficient as a search target (for example, ``\fB(S\fR'' matches any annotation with an \fBaux\fR string beginning with these characters, such as ``\fB(SVTA\fR'' or ``\fB(ST0+\fR''). .PP To repeat a search forward, press the key; to repeat a search backward, press the key. If you use these keyboard shortcuts without having defined a search target, behaves in the same way as , and in the same way as (moving to the adjacent screenful in the appropriate direction). .SS Printing .PP You can print the current contents of the main \fBwview\fR window, or any selected segment of the current record, by selecting \fBPrint...\fR from the \fBFile\fR menu to bring up the \fBPrint\fR dialog. Choose the output device from the \fBPrinter\fR list. Select the range (time interval) to be printed by choosing either \fBEntire Record\fR, \fBCurrent Contents of Window\fR (the default), or \fBSegment\fR. If you choose \fBSegment\fR, enter the times of the beginning and end of the desired segment in the \fBFrom:\fR and \fBTo:\fR fields. Press \fBOK\fR to begin printing, or \fBCancel\fR to return to \fBwview\fR without printing. .SS Help .PP On-line help is available by selecting a topic from the \fBHelp\fR menu, or by selecting any control and pressing the \fBF1\fR key. The \fBHelp\fR menu topics include most of the text of this \fBman\fR page. .SH ENVIRONMENT .TP \fBWFDB\fR The database path: a list of directories that contain database files. An empty component is taken to refer to the current directory. All applications built with the \fIwfdb\fR(3) library search for their database input files in the order specified by \fBWFDB\fR. If \fBWFDB\fR is not set, searches are limited to the builtin WFDB path (see \fBsetwfdb\fR(1)). Under MS-DOS/MS-Windows, directory names are separated by semicolons (;), and the format of \fBWFDB\fR is that of the MS-DOS \fBPATH\fR variable (colons may be used following drive specifiers within \fBWFDB\fR in this case). .TP \fBWFDBCAL\fR The name of the WFDB calibration file (see \fBwfdbcal\fR(5)), which must be in a directory named by \fBWFDB\fR (see immediately above). This file is used by \fBwview\fR to determine standard scales for signals other than ECGs. If \fBWFDBCAL\fR is not set, the default WFDB calibration file is used (see \fBsetwfdb\fR(1)). If the calibration file is not readable, signals may be drawn at incorrect scales. .PP After determining appropriate values for these variables, you may wish to add commands for setting them to your \fIautoexec.bat\fR file. .SH INSTALLATION .PP The current version of \fBwview\fR requires manual installation of a few files: .br .TS center; l l. \fIwview.exe\fR \fBwview\fR itself, in Windows executable form \fIwview.hlp\fR the compressed MS Windows Help file for \fBwview\fR \fIwfdb.dll\fR the WFDB library, compiled as a large model MS Windows DLL .TE .br All of these files should be installed in the same directory, which should be somewhere in your \fBPATH\fR; the main MS Windows directory (usually \fBc:\\windows\fR) seems to be the most popular choice for commercial MS Windows applications, and is suitable for this purpose. Be certain that you do not overwrite other files of the same names, however (I don't know of any commercial applications that use these file names, but check your system to be safe). At this point, it is possible to start \fBwview\fR using the command-line interface. .PP To install a \fIwview\fR icon in the Program Manager workspace, select (click once on) a program group (such as `Applications'). Select \fBNew...\fR from the Program Manager's \fBFile\fR menu, choose \fBProgram item\fR from the \fBNew Program Object\fR dialog that appears, and click on \fBOK\fR. The \fBProgram Item Properties\fR dialog then appears. Enter ``\fBWFDB Browser\fR'' in the \fBDescription:\fR field, and the full pathname of \fIwview.exe\fR in the \fBCommand line:\fR field, then click on \fBOK\fR. It is now possible to start \fBwview\fR by clicking on its icon. .PP Finally, open the MS Windows File Manager and choose \fBAssociate...\fR from its \fBFile\fR menu. Enter ``\fBhea\fR'' in the \fBFiles with extension:\fR field, and click on \fBBrowse\fR. Find and select \fIwview.exe\fR using the \fBBrowse\fR dialog, and click on \fBOK\fR. This procedure makes it possible to start \fBwview\fR simply by double-clicking on any WFDB header (\fB.hea\fR) file. .SH BUGS .PP Probably many. Please send your comments, suggestions, and bug reports to the author: George B. Moody .br MIT Room E25-505A .br Cambridge, MA 02139 USA .br .br Internet: george@mit.edu .PP A significant known bug is that only one instance of \fBwview\fR may be run at any given time. This is a consequence of using a large memory model DLL (in this case, \fBwfdb.dll\fR) under MS Windows 3.1. Fixing this bug is a very low priority (i.e., not likely to happen soon unless it is fixed by a future version of MS Windows). If you are careful, it is possible to have two or more instances running simultaneously \fIprovided that the same record (and annotator, if any) are open in all instances\fR. Exit cleanly by iconifying (closing) all instances first, then quit each instance without reopening the window. .SH SEE ALSO \fBpschart\fR(1) (for PostScript), \fBview\fR(1) (for MS-DOS), \fBwave\fR(1) (for X11), \fBgtkwave\fR(1) (for MS-Windows) .SH AUTHOR George B. Moody (george@mit.edu) .SH SOURCES http://www.physionet.org/physiotools/wfdb/wview/