Entropy-statistical approach to phase-locking detection of pulse oscillations: application for the analysis of biosignal synchronization
This work addresses synchronization analysis in biosignals, but it is incremental as it builds on existing entropy-based methods with specific adaptations for pulse oscillations.
The authors tackled the problem of detecting synchronization in oscillator systems by proposing a new method based on fuzzy entropy calculated from pulse period ratios, which effectively visualizes synchronized modes using entropy maps and classifies states based on embedding vector dependencies. They demonstrated its application to biosignal synchronization, such as in rat hippocampus rhythms, making it promising for mobile digital platforms.
In this study a new method for analyzing synchronization in oscillator systems is proposed using the example of modeling the dynamics of a circuit of two resistively coupled pulse oscillators. The dynamic characteristic of synchronization is fuzzy entropy (FuzzyEn) calculated a time series composed of the ratios of the number of pulse periods (subharmonic ratio, SHR) during phase-locking intervals. Low entropy values indicate strong synchronization, whereas high entropy values suggest weak synchronization between the two oscillators. This method effectively visualizes synchronized modes of the circuit using entropy maps of synchronization states. Additionally, a classification of synchronization states is proposed based on the dependencies of FuzzyEn on the length of embedding vectors of SHR time series. An extension of this method for analyzing non-relaxation (non-spike) type signals is illustrated using the example of phase-phase coupling rhythms of local field potential of rat hippocampus. The entropy-statistical approach using rational fractions and pulse signal forms makes this method promising for analyzing biosignal synchronization and implementing the algorithm in mobile digital platforms.