中文摘要：

跌倒是造成世界上意外伤害死亡的第二大原因，如何预防跌倒已成为保障老人生命的关键。目前常见“跌倒报警器”的传感模块一般采用单一的三轴加速度计，测量精度受限，仅能实现人体跌倒后的报警功能而不能实现跌倒前的预警。文章设计并实现了一种基于 MEMS 惯性传感单元的防跌倒预警器，率先设计了含“三轴加速度计＋三轴陀螺仪＋三轴磁力计”的高精度多模态传感模块，内嵌跌倒预警算法，并通过蜂鸣器和振动器警示。对九名健康年轻实验对象进行了总计81次的跌倒实验，系统结合基于阈值的跌倒预警算法，结果表明，其检测灵敏度可达98.61%且特异度为98.61%，平均预警时间为300 ms。未来研究将嵌入全球移动通信系统（Global System For Mobile, GSM）、全球定位系统（Global Positioning System, GPS）等电路模块功能及配备穿戴式安全气囊，有望在易跌人群中实现实时防护和及时救治。

英文摘要：

Falls are the second leading cause of unintentional injury deaths worldwide, so how to prevent falls has become a safety and security problem for elderly people. At present, because the sensing modules of most fall alarms generally only integrate the single 3-axis accelerometer, the measurement accuracy of sensing signals is limited. They can only achieve the alarm of post-fall detection but not the early pre-impact fall recognition in real fall applications. Therefore, an early pre-impact fall alarm system based on high-precision inertial sensing units was studied and developed in this paper. A multi-modality sensing module embedded with the fall detection algorithm was developed for the early pre-impact fall detection. The module included a 3-axis accelerometer, a 3-axis gyroscope and a 3-axis magnetometer, which could arouse early pre-impact fall warnings by a buzzer and a vibrator. Total 81 times of fall experiments from 9 healthy subjects were conducted in simulated fall conditions. The result shows that the detection sensitivity of the system combining the early warning threshold algorithm can reach 98.61%with a speciifcity of 98.61%, and the average pre-impact lead time is 300 ms. In the future, GPS, GSM electronic modules and wearable protected airbags will be embedded in the system, which will enhance real-time fall protections and timely treatments for the elderly people.