Multiscale Poincare Plots

Description

Poincaré delay maps are widely used in the analysis of cardiac interbeat interval (RR) dynamics. To facilitate visualization of the structure of these complex time series, we introduced a methodology called multiscale Poincaré (MSP) plots.

Briefly, the function MsPplots.m (version 1.0) starts with the original time series and employs a coarse-graining procedure to create a set of time series, each of which represents the system’s dynamics on a different time scale. Next, Poincaré (delay) plots are constructed (using the function dscatter.m by Robert Henson) for the original and the coarse-grained time series. Finally, as an optional adjunct, color can be added to each point to represent its normalized frequency.

The functions have been tested on Matlab R2010b, R2014b and R2015a on April 11 2016.

Usage

Inputs to the MsPplots.m function are:

• The time series vector with one column (mandatory)
• The number of time scales (integer; default: scales = 12)
• Poincaré plots from scale 1 to scales by scstep. (integer; default: scstep = 1)
• The number of rows in the plot montage (integer; default: nrwo = 3)
• The number of columns in the plot montage (integer; default: ncol = 4)
• A option that allows to save the final figure (boolean; default: 1)
• The name of the figure to be saved (default: Figure1.png)

Also provided, are two example scripts that employ deidentified RR time series from two sources: one from the database for Chaos Is the Normal Heart Rate Chaotic? and the other from the Normal Sinus Rhythm RR Interval Database, both available at PhysioNet.

The first example script requires the text file n2-filtered included in this directory, and the second one requires the WFDB Matlab toolbox to access data from Physiobank.

Licensing

The helper function dscatter.m is written by a separate author and is covered by the BSD License under Mathsworks. The rest of the software in this directory is licensed under the GNU Public License 3.

Contributors

The Multiscale Poincare Plot (MSP) package was developed by Teresa S. Henriques, Sara Mariani and Anton Burykin. A detailed description can be found in the citation.