Example of a measurement

Here is an example to show how the measurement is performed and what must be respected.

1. Program preparation

The game to be measured must be started and all settings made according to the measurement run (low resolution for screen capture measurement). Set the game so that the subject can start playing immediately. Bring the game into pause mode and return to the desktop with Alt-Tab.

The screen capture program must be started. For Camtasia Studio, set the program to start and stop recording using a shortcut key. In the options of Camtasia before the video and audio codecs adjust (DivX) for this compression is used.

Very important! At the beginning of the video, the system time must be displayed so that the data can be adjusted later by the Lightstone! So look in the options to see if this setting is active. At best, the recording should be tested in advance, if really everything is right (codec, time display).

2. Subject survey

There should be no problems here. Each subject receives a number that can be used for the file names.

3. Connection of the subject to the "Lightstone"

The Lightstone has three sensors, one of which is provided with a golden dot. This sensor measures the pulse rate and must be attached to the middle finger. The other two sensors measure skin resistance and are placed on the index and ring fingers. It is very important that the sensors have good grip on the finger and do not hang loosely on the finger.

To check whether the sensors provide meaningful data, the "Lightstone Monitor" can be used.

4. Prepare Lightstone Monitor

his program requires administrator rights under Windows XP, otherwise the device will not be recognized (the "Status Log" window should indicate that a device has been found).

Under "Options" you will find the menu item "Record to Datafile". Here, the XML format must be selected and a file name entered. Now the recording can be started with the "Start" button.

It is an advantage to consider the first minute as a test first. During this time you can see if the data is correct or if the sensors are not sitting properly. After a value is displayed in the HRV (SDNN) window, you can switch to the game.

5. Video recording of the subject

In the "test minute", the recording of the subject can be started. Since this recording takes place on a second PC, synchronization of the system times of both computers must already have taken place. The system time must also be in the player video, so that synchronization can take place later.

6. The measurement

After the game appears on the monitor, the key combination must begin recording the screen. Now the game can be started. During the game the subject must keep the hand being measured as calm as possible so that the values ??are not distorted by pressure changes on the sensors.

7. End of the measurement

When the game is over, the keyboard shortcut closes the screen capture process and the player's capture. Alt-Tab takes you back to Windows to stop recording the data.

If everything worked, there are now 2 videos (vp0000_game.avi; vp0000_player.avi) and data (vp0000.xml).

On this occasion, the subject can be interviewed immediately after an assessment of the duration of the game. The answer to this question can be noted on the questionnaire from the beginning.

8. Evaluation of the game

The evaluation of the game video is now done with the program "Video Analyzer". After completing the evaluation, the file just created (vp0000.quest) is added to the existing data.

9. Evaluation of the measurement

he evaluation of the measurement is done with the program "Flow Player". All measured values (vp0000.xml) and the evaluation file (vp0000.quest) are brought together and the flow state is determined. These data can then be stored as a binary file (vp0000.data) together with all information about start time and frame ratio. This has the advantage that the information does not have to be reentered each time. Another advantage is the reduction of the file size of the measured values.