Signal stationarity assessment for the heart rate variability spectral analysis

The results of experimental examination of different approaches to the signal stationarity assessment with regard to the heart rate variability spectral parameters estimation are presented. The following three approaches were considered: autoregressive parameters monitoring; analysis of detrended signal and assessment of generalized likelihood ratio. The above methods were examined with the use of both artificially modeled signals and a set of real signal recordings. A combination of parameters providing least values of nonstationarity detection error was determined for each method. It was shown that the three methods demonstrate similar performance, while the obtained errors can be reduced by their joint use and also by taking into account some additional statistical indexes (such as signal mean value and variance).