基于 MEMS 传感器的可穿戴式老年人跌倒监测系统的设计

摘要

To design a falling detection device, aiming to reduce the delay of helping the tumbling old men and to enhance their safety.This device combined MEMS (micro-electro-mechanical systems) sensor and digital signal processing with wireless trans-mission technology so as to be used on smart phones.To distinguish falling accidents from daily behaviors, it could be judged from body′s triaxial accelerometer and angular speed and proper threshold value selected from lots of experiments.The data could be sent to their phones, through Bluetooth and given out alarm through cellular voice, and besides, their location located by GPS and their condi-tions would be texted to the hospital and their guardians.Then after falling,the old people could be helped in the shortest time.Lots of experiments showed that the accuracy rate of the judgment from the combination of triaxial accelerometer and angular speed was 100%, compared to that of traditional judgment from triaxial accelerometer which was 84.29%.The result shows that the wearable falling de-tection device based on MEMS sensor has the characteristics of convenience, accuracy and low power dissipation and has the ability of detecting falling accurately and giving out alarm.It meets the requirements of falling monitoring.%为了缩短老年人跌倒后的救助时间和提高安全保障，我们设计了一种基于加速度和角速度传感器的跌倒监测装置。该装置结合机械微电子系统（ microelectro mechanical system，MEMS）传感器、数字信号处理及无线传输技术应用于智能手机上。为区分人体跌倒事件和日常行为，结合人体三轴加速度和角速度联合对跌倒事件进行判断，通过大量实验选取合适阈值。针对老年人的生活特点，数据通过蓝牙装置发送至手机上进行处理，通过手机语音报警、手机GPS定位系统和短信通知医院和用户监护人，使得老年人跌倒后能够在第一时间获得救治，减小伤害。经过大量的实验测试结果统计，相比较于传统的三轴加速度判断跌倒事件，结合三轴加速度和加速度联合判断使该系统的准确率从84．29％提高至100％。结果表明：基于MEMS传感器的可穿戴式跌倒监测系统具有便捷、准确、功耗低的特点，能够准确监测出跌倒事件并进行报警。