What is VARVI?

VARVI (heart rate Variability Analysis in Response to Visual stImuli) is a free software tool developed to perform heart rate variability (HRV) analysis in response to different visual stimuli. The tool was developed after realizing that this type of studies are becoming popular in fields such as psychiatry, psychology and marketing, and taking into account the lack of specific tools for this purpose.

VARVI allows the users to obtain Heart Rate (HR) records from subjects who are watching video files or sets of images. In case video files are used, each video file will be labelled with a tag, and the HR record will contain information of these tags with their corresponding time intervals. When using sets of images, users specify directories containing images, and each directory will be associated with a tag.

Feel completely free to use VARVI in your research. You can cite our work with this reference:

Rodriguez-Linares, L.; Cuesta, P.; Alonso, R.; Mendez, AJ.; Lado, M.J.; Vila, X.A, VARVI: A software tool for analyzing the variability of the heart rate in response to visual stimuli," Computing in Cardiology Conference (CinC), 2013 , vol., no., pp.401,404, 22-25 Sept. 2013

Who did VARVI?

VARVI was developed by researchers belonging to the MILE (bioMedical Informatics and signaL procEssing) Group of the University of Vigo (Spain). The following researchers contributed to its development:

• Leandro Rodríguez-Liñares
• Pedro Cuesta
• Raúl Alonso
• Arturo J. Méndez
• María J. Lado
• Xosé A. Vila

What does VARVI need to work?

• It runs on GNU Linux and Windows operating systems.
• It depends on external software to show the video files (see installation procedure below).
• Images must be in .jpg format (.jpg and .jpeg extensions)
• It depends on Python and the PyBluez and PyGame libraries.
• VARVI obtains the data from a Polar Wearlink®+ transmitter with bluetooth® band. This band must be linked with the computer where VARVI is running. For testing purposes, a simulation mode (without band) is available that creates random data.

Installation on GNU Linux systems

• Download the zip file containing the software and uncompress it.
• VARVI depends on VLC to play the video files. Besides, PyBluez and PyGame libraries must be installed on the system. On Debian/Ubuntu based systems, these dependencies can be installed using the following command in a terminal:
  sudo apt-get install vlc python-pygame python-bluez

Installation on Windows systems

1. Download the zip file containing the software and uncompress it.
2. Install Python 2.7.X (available here). To add the python executable file to the path of the system, you have to follow these steps:
   • Hold "Win" and press "Pause" to open the Control Panel
   • Click "Advanced System Settings"
   • Click "Environment Variables"
   • Append ";C:\python27" to the Path variable
   • Restart Command Prompt
3. Install the PyBluez libraries (available from here) in the system. Be sure to download and use the file named "PyBluez-X.Y.win32-py2.7.exe".
4. Install the PyGame libraries (available from here) in the system. Be sure to download and use the file named "pygame-X.Y.Z.win32-py2.7.msi".
5. Download and install VLC (use the EXE installer available here).