Nonlinear Characteristic Analysis of Ballistocardiogram Signals Based on Chaotic Time Series

The nonlinear characteristics of Ballistocardiogram (BCG) are analyzed based on chaotic time series in this paper. First of all, a set of seated BCG acquisition device is designed using piezoelectric thin film sensors, and ECG signals are collected synchronously. Then, the digital signal processing is performed on the collected signals and the feature points are marked. The synchronization between the collected BCG signals and the ECG signals is verified through the comparison and analysis of the characteristic point spacing. Finally, the interval scatter plots (Lorenz plots) and phase space reconstruction map of the two kinds of signals are plotted. The Lorenz plots are compared and the reconstructed phase spatial statistics of the two signals are extracted. The results show that the BCG signal nonlinear characteristics of different individuals have certain commonalities and differences, which can be used as the basis for diagnosing cardiac status.