Research On Non - Contact Symmetry Signaling Signal Processing Method Based On Empirical Mode Decomposition

Non-contact vital signs monitoring system is an instrument that detect human body’s vital signs in the condition of contactless. The system can monitor the breathing and heartbeat signals through the clothes, quilts and other obstacles of humans in distance and non-contact. The system can be used for critically ill patients, infectious disease of the clinical care of patients, and real-time monitoring and newborn infant family. Avoid contact with the electrode systems of physical harm and human guardianship intermittent.This article mainly discusses the separation algorithm of signals of the non-contact vital signs monitoring system. Aim at the shortcomings of the traditional time-frequency analysis in dealing signal. Use the empirical mode decomposition (EMD) and add window empirical mode decomposition (WA-EMD) algorithm to process the signal. The algorithm can decompose a complex signal into a series of components of the IMF in different frequency. The article introduces the basic principles and process of EMD algorithms and uses this algorithm to separate the true signals from the non-contact system. After several tests we found that the EMD method can’t separate the breathing and heartbeat signals. The article also introduced why the EMD method can’t separate the breathing and heart-beating signals.Because of the limitation of the EMD algorithm in processing vital signs signal, the article proposed using window average empirical mode decomposition(WA-EMD).This method is obtained the mean envelope signal by adding the window, but not the Cubic Spline Interpolation. It overcomes the Mode Mixing. After several times of simulation experiments, it is involves that the method can separate the breathing and heart-beating signals, And the method has good noise immunity.The end of the article is this system’s hardware design and implementation, it also has written the software programs of the WA-EMD algorithms. Eventually, the debugging and realization of WA-EMD is based on DSP chip TMS320C6713. The result shows that the algorithm is validity and feasibility in dealing with the breathing and heartbeat signal.