Matlab Software for Detrended Fluctuation Analysis of Heart Rate Variability

The analysis of heart rate variability (HRV) is an important tool for the assessment of the autonomic regulation of circulatory function. HRV analysis is usually performed using methods that are based on the assumption that the signal is stationary within the experiment duration, which is generally not true for long-duration signals (e.g., 24-hour Holter) or signals acquired during stress tests. This paper presents a Matlab tool for detrended fluctuation analysis (DFA) of HRV signals. DFA is applicable in the context of nonstationary signals, since it involves removing fluctuation trends from the signal. The software is validated using simulated signals with different power-law characteristics, and then demonstrated using real HRV signals, obtained from three groups of subjects: healthy volunteers, individuals with Chagas disease, and individuals with mild to moderate