Design and Realization of an Early Pre-Impact Fall Alarm System Based on MEMS Inertial Sensing Units

• Published in: Applied Mechanics and Materials Vol. 461; no. Advances in Bionic Engineering; pp. 659 - 666
• Main Authors: Liang, Ding, Zhao, Guo Ru, Ning, Yun Kun, Zhang, Qi, Li, Hui Qi
• Format: Journal Article
• Language: English
• Published: Zurich Trans Tech Publications Ltd 01.11.2013
• Subjects: Alarm systems; Algorithms; Detection; Devices; Elderly people; Inertial; Modules; Warning; Early Fall Alarm; Inertial Sensor; Threshold Algorithm
• ISBN: 3037859326; 9783037859322
• ISSN: 1660-9336; 1662-7482; 1662-7482
• DOI: 10.4028/www.scientific.net/AMM.461.659

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 alarm devices generally only integrate the single 3-axis accelerometer, so the measured accuracy of sensing signals is limited. It results in that these devices can only achieve the alarm of post-fall detection but not the early pre-impact fall recognition in real fall applications. Therefore, this paper aimed to develop an early pre-impact fall alarm system based on high-precision inertial sensing units. A multi-modality sensing module embedded fall detection algorithm was developed for early pre-impact fall detection. The module included a 3-axis accelerometer, a 3-axis gyroscope and a 3-axis magnetometer, which could arouse the information of early pre-impact fall warning by a buzzer and a vibrator. Total 81 times fall experiments from 9 healthy subjects were conducted in simulated fall conditions. By combination of the early warning threshold algorithm, the result shows that the detection sensitivity can achieve 98.61% with a specificity of 98.61%, and the average pre-impact lead time is 300ms. In the future, GPS, GSM electronic modules and wearable protected airbag will be embedded in the system, which will enhance the real-time fall protection and timely immediate aid immensely for the elderly people.