Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, 40136 Bologna, Italy.
Department of Clinical Gerontology, Robert-Bosch-Hospital, 70376 Stuttgart, Germany.
Sensors (Basel). 2015 May 20;15(5):11575-86. doi: 10.3390/s150511575.
Falls among older people are a widely documented public health problem. Automatic fall detection has recently gained huge importance because it could allow for the immediate communication of falls to medical assistance. The aim of this work is to present a novel wavelet-based approach to fall detection, focusing on the impact phase and using a dataset of real-world falls. Since recorded falls result in a non-stationary signal, a wavelet transform was chosen to examine fall patterns. The idea is to consider the average fall pattern as the "prototype fall".In order to detect falls, every acceleration signal can be compared to this prototype through wavelet analysis. The similarity of the recorded signal with the prototype fall is a feature that can be used in order to determine the difference between falls and daily activities. The discriminative ability of this feature is evaluated on real-world data. It outperforms other features that are commonly used in fall detection studies, with an Area Under the Curve of 0.918. This result suggests that the proposed wavelet-based feature is promising and future studies could use this feature (in combination with others considering different fall phases) in order to improve the performance of fall detection algorithms.
老年人跌倒已被广泛记录为公共卫生问题。自动跌倒检测最近变得非常重要,因为它可以允许医疗援助立即了解跌倒情况。本工作的目的是提出一种新的基于小波的跌倒检测方法,重点关注冲击阶段,并使用实际跌倒数据集。由于记录的跌倒会产生非平稳信号,因此选择小波变换来检查跌倒模式。其想法是将平均跌倒模式视为“原型跌倒”。为了检测跌倒,可以通过小波分析将每个加速度信号与该原型进行比较。记录信号与原型跌倒的相似性是可用于确定跌倒与日常活动之间差异的特征。在实际数据上评估了该特征的判别能力。它优于跌倒检测研究中常用的其他特征,曲线下面积为 0.918。这一结果表明,所提出的基于小波的特征很有前途,未来的研究可以使用该特征(结合考虑不同跌倒阶段的其他特征)来提高跌倒检测算法的性能。