POLYAN: a package for a polyparametric approach to cardio-respiratory variability signals analysis.

POLYAN, a computer program based on a point-and-click graphical user interface for easy and efficient polyparametric analysis of cardio-respiratory variability signals is described. The main tasks performed by the package are: univariate and bivariate spectral analysis on selected portions of the signals with the computation of some clinically relevant indices and baroreflex sensitivity assessment by the analysis of the relationship between systolic pressure and heart period signals. Some tools which help the analyst in the solution of common practical problems have been implemented to make analysis easier and more rigorous. Using Matlab language, POLYAN has the flexibility and expandability necessary for a research tool, which often requires implementation of new algorithms and computation of new parameters.