用于步态分析的足底压力监测系统研究进展

Research progress of the plantar pressure monitoring system for gait analysis

随着我国人口老龄化的加剧,人们对于健康监测的需求逐步提高,步态分析作为分析个体生理信号和提供人体物理信息的重要评估工具,在疾病诊断、预防跌倒、康复、人机交互等领域的应用日益广泛.本文首先介绍了步态分析的重要性和足底压力监测的研究现状,以及各种足底压力监测系统的特点.其次,总结了足部生理特征,即足底压力中心点和步态相位的常用划分方法;分析了用于足底压力监测的各种柔性压力传感器——其材料及特点、集成和连接方式,概述了常用的步法识别算法.最后,对足底压力监测系统的设计方向以及进一步研究提出了建议.

With the aging of the population in China, people’s demand for health monitoring is gradually increasing. As an effectiveway of health monitoring, gait analysis is increasingly widely used in disease diagnosis, fall prevention, rehabilitation,human-computer interaction and other fields. Gait reflects the interconnectedness of multiple physiological systems,including balance, strength, and cardiovascular capacity, and a person’s gait can tell us a lot about their health. Gait analysisis a systematic study of human walking movements and an important evaluation tool for analyzing individual life signals,which can be accomplished by collecting, describing and characterizing kinetic and mechanical data of gait.Firstly, this paper introduces the importance of gait analysis and the research status of plantar pressure monitoring, aswell as the characteristics of various plantar pressure monitoring systems.Secondly, the physiological characteristics of the foot are summarized, including the common division methods of thecenter point of plantar pressures and gait phases.Then, the materials and characteristics of the key device for gait analysis data acquisition, flexible pressure sensors, aresystematically analyzed. In the meantime, integration and connection modes of sensors, and common step recognitionalgorithms are also summarized. Detailedly, according to the sensing principle, the flexible pressure sensor can be dividedinto piezoelectric, capacitive, piezoresistive, triboelectric, photoelectric, magnetic induction and pneumatic flexiblepressure sensors. Piezoelectric flexible sensors do not require external power supply, have high sensitivity and long servicelife, but cannot monitor static forces, and the preparation process is more complicated than that of other sensors. Thetriboelectric sensor has advantages of various types, wide range of available materials, simple structures, self-power supplyand good biocompatibility. The capacitive flexible sensor has the characteristics of high sensitivity and fast response, but itsportability is poor and easy to be interfered by environmental factors. The piezoresistive sensor has good flexibility andhigh sensitivity. The photoelectric sensor has the characteristics of anti-electromagnetic interference, high sensitivity, lightweight and so on. The magnetic induction sensor has high conversion efficiency and fast response ability, but there arecommon errors caused by hysteresis, and it is very sensitive to external magnetic field interference. Pneumatic sensors aresluggish and bulky.Finally, the design direction and further research of the plantar pressure monitoring system are discussed. At present,although there have been a lot of research on gait analysis at home and abroad, the following three aspects need to beimproved in order to realize large-scale and normalized gait monitoring. First, to meet the needs of customization, for somespecific diseases and special populations, the system needs to be able to be flexibly adjusted. Second, formulate completeindustry standards. For smart insoles, shoes and socks, to enable telemedicine services and long-term sole pressuremonitoring, it is necessary to standardize the various principles of sensors and ensure the safety of long-term use. Third,improve data processing technology. Through the fusion of various algorithms, the feature classification and extraction ofdata are carried out to improve the accuracy of gait judgment and reduce the misjudgment rate. The Internet of Thingstechnology is utilized to improve the efficiency of data processing and transmission, and obtain greater data storage space.