Abstract
This article deals with the issue of usability of an exploratory data analysis tool in the field of medicine. The text portion contains a description of the methods and the visualization procedure. It analyses the current state on usability, medical data visualization and presents the benefits of visualization tools. The goal of this research was to design and implement a suitable visualization tool for the provided dataset, which is the result of cooperation between Technical university of Košice and East Slovak Institute of Heart and Vascular Diseases (VÚSCH) and presents cardiovascular disease data. The resulting web application aimed to provide potential users with an overview of cardiovascular diseases and the influence of their lifestyle on the assumption of such a disease, and for experts to provide different forms of viewing the given data, as well as to facilitate their work. The application was then tested for usability in two iterations where corrections and improvements were made based on the given feedback. Thanks to this iterative procedure and careful reflection of the user feedback the application received endorsement as a valuable tool by the expert evaluator.