The higher-order spectra as a tool for assessing the progress in rehabilitation of patients after ischemic brain stroke

Abstract

This article explores the possibility of using the higher-order spectra as a tool to determine the progress in rehabilitation of patients after ischemic brain stroke (IBS). In order to evaluate the effectiveness of this tool patients’ heart rate variability (HRV) recordings obtained at 1, 10 and 60 day after stroke are listed and compared to those recorded for healthy individuals. Each set of HRV signals is processed with bispectral and bicoherent analysis. In each case three statistical parameters are observed. The values of investigated parameters differ for healthy people and these affected by the IBS and the rehabilitation progress is visible based on the parameters changing their values towards these characteristic for healthy individuals. The obtained results show usefulness of higher-order spectra as a tool for assessment of the rehabilitation progress. Authors believe that further work would greatly improve potential of the described tool, allowing to increase its precision and expand the application field.