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Result storage and export

Result storage:

Analysis results of all analyses (except ERPs/ERF which are stored in one file per ERP/ERF in the study folder) are stored in a database using Structured Query Language (SQL). This database can be a local file in the study folder or a local or network SQL server. The server connection is configured using the SQL page on the "Configure study" dialog:

Enter database driver (type), hostname, port, username, password, database name in the corrseponding fields. You can test the database access using the "Test connection"-button. Qt in general can handle multiple database types. But support for some SQL configurations (like for MySQL, PosgreSQL among others) depends on your QT installation and the available SQL driver plugins in this installation. Some of these plugins are not compatible with the LGPL license, and are therefore not included in every QT installation.

This single file based database should be available in all Qt installations. By default, the database file is stored in the studyfolder and named as the studyfolder with an ".sqlite" file extension. Be sure to make backups of this file to avoid losing editing results. Corrupted SQLite-databases can be repaired in some cases, but nothing but a backup will protect you against user errors!

To use a MySQL database, a mysql server must be reachable under the specified connection options. Additionally, the Qt MySQL plugin must be available.
On Linux, precompiled binaries should be available for your distribution and can be downloaded and installed using the standard software installation routines (e.g. YAST on SUSE).
On Windows, the MySQL plugin may not be available and needs to be recompiled. Aditionally the libmySQL.dll needs to be found by Qt, so the MySQL bin-directory (e.g. C:\Program Files\MySQL\MySQL Server 5.1\bin) needs to be added to the PATH variable.

For further help, refer to the QT documentation on how to setup SQL support for your specific configuration.

Although QT supports a large variety of SQL drivers, at the present stage EMEGS supports only two driver types: QSQLITE for local single-file databases, and  QMYSQL for the work with a MySQL-server! Support for other drivers may be added in future releases.

You can check on the data in the database with (often times free) database software corresponding the type of your database, such as sqlite-studio for SQLite databases or mysql-workbench for MySQL-servers. A sample view with sqlitestdudio (v2.1.5) of a study database (called ECS) is shown here:

Database structure:

Each study database has a subjects and a sessions table. For each analysis performed, there will be additional tables usually named as the analysis itself (e.g. ecg for and ECG analysis or startle for a STARTLE analysis) which contain the main analysis results and sometimes a helper table (e.g. ecg_analysis or startle_analysis) with internally needed information about the state of the analysis  (e.g. where sto continue a previously interrupted session)  which is not psychophysiologically meaningful and not interesting for normal users. You can reset a database (deleting all tables except subjects and sessions and emptying these two tables) using the "Reset database"-button on the SQL-page on the Configure-Study-Dialog. If you wish to remove contents from the database more selectively, you can use the "Remove data & segments"-dialog.

Result export:

Results can be exported using the value export which is described in detail in the statistics section.

Third-party database software (such as sqlite-studio for SQLite databases or mysql-workbench) offer the possibility to export tables to a text-file, which can be another way to retrieve your analysis results.

Parameter list:

The following list describes all the parameters that can be extracted/calculated by EMEGS (Qt version). The Parameter column contains the name of the parameter that EMEGS uses in the data export - not scientifically correct names.

Comman lab  range
Interbeat-Interval, synonymous to RR-Interval (distance between an R-wave and the subsequent R-wave)

Heart rate (beats per minute), equals 60000/IBI

ECG_TWA T-wave amplitude (amplitude at T-wave maximum minus base level)

ECG_PQ PQ-Interval

ECG_QT QT-Interval

ECG_QTC_BAZETT Corrected QT-Interval, using Bazett's formula ( QTC_BAZETT=QT/SQRT(IBI/1000)  )

ECG_RWA R-wave amplitude (amplitude at R-wave maximum minus base level) *

ECG_PONSETTIME P-wave onset time

ECG_QONSETTIME Q-wave onset time s

ECG_RMAXTIME R-wave maximum time s

ECG_SMINTIME S-wave minimum time s

ECG_TMAXTIME T-wave maximum time s

ECG_TOFFTIME time of T-wave offset

ECG_BASELEVEL zerolevel of ECG at this beat
raw skin conductance level

EDA_SCL_E edited skin conductance level microS 0-60

EDA_SCL_EF edited and filtered skin conductance level microS 0-60

tonic component after decomposition

EDA_PHAS phasic driver after decomposition








* = depending on amplifier setting        t = time point in seconds since start of recording, range depending on recording session