Study On The Balance System Based On The Multivariate Mutiscale Entropy

As the statistics show, falling is the main source of unintentional injury in the elderly. Previous studies have indicated that upgrade subthreshold mechanical cutaneous stimuli can enhance the detection and transmission of weak signals in neurophysiological systems. This phenomenon, which is called as stochastic resonance, can help to improve the performance of the human balance control system. There are three major vibration:eccentric rotating mass (ERM), linear resonant actuator (LRA) and piezoelectric vibration generator (PVG). However, most of these equipments are too large that patients need to stand still for treatment, and the vibration is not strictly random.Based on the previous researches of the fall prevention, fall-risk evaluation and balance enhanced, this paper is mainly focus on the evaluation and enhance of balance evaluation. A scientific and credible measurement system is built up for the purpose to evaluate the postural stability, then this measurement system will be applied to validate whether the treatment system can help to improve the sense of balance. This paper uses the center of pressure (COP) to measure postural stability. For the non-linear and non-stationary feature of COP data, this paper adopts Empirical Mode Decomposition (EMD), Multivariate Empirical Mode Decomposition (MEMD), Muti-scale Sample Entropy (MSE) and Multivariate Muti-scale Sample Entropy (MMSE) to analyze COP data. In treatment system, this paper develops vibration shoes controlled by touch-type switch for the purpose to improve balance stability of elderly. We are more concentrated on the random vibration controlled by touch-type switch and the lightness of the vibration shoes. The vibration shoes can generate mechanical vibration noise to stimulate feet when patients walking in this shoes.This paper design two experiments:assessment experiment and treatment experiment. Through the analysis of COP data in two groups, MMSE based on MEMD is able to discriminate very small change of postural stability after the use of vibration shoes by a statistically significant difference. The result also indicates that our vibration soles controlled by touch-type switch can improve elderly subjects balance stability to a certain extent.