VARVI: A software tool for analyzing the variability of the heart rate in response to visual stimuli

This paper describes a free software tool (VARVI) developed in our research group to facilitate the analysis of heart rate variability (HRV) in response to different visual stimuli. uliThis tool was developed after the realization that this type of studies are becoming to be used in fields such as psychiatry, psychology and marketing and that there are no specific tools for this purpose. It has been developed in python language and tested on Linux but extensible to other operating systems. It requires the connection of a Bluetooth chest strap Polar WearLink to the subject. The researcher selects a set of videos of any duration and the application shows them to the subject in a predefined or random order, while the heart rate is recorded. The result is a pair of text files that can be read by other HRV tools developed in our group (RHRV or gHRV). VARVI has been used for analyzing the response to watching the videos of the last Galician election campaign in a group of 90 people. It will be used in a project whose goal is to analyze the impact of traffic accidents prevention campaign in Spain and also in a research with depressed patients, in collaboration with the Hospital of Ourense.