Lee Jung Keun, Robinovitch Stephen N, Park Edward J
IEEE Trans Neural Syst Rehabil Eng. 2015 Mar;23(2):258-66. doi: 10.1109/TNSRE.2014.2357806. Epub 2014 Sep 19.
Although near-falls (or recoverable imbalances) are common episodes for many older adults, they have received a little attention and were not considered in the previous laboratory-based fall assessments. Hence, this paper addresses near-fall scenarios in addition to the typical falls and activities of daily living (ADLs). First, a novel vertical velocity-based pre-impact fall detection method using a wearable inertial sensor is proposed. Second, to investigate the effect of near-fall conditions on the detection performance and feasibility of the vertical velocity as a fall detection parameter, the detection performance of the proposed method (Method 1) is evaluated by comparing it to that of an acceleration-based method (Method 2) for the following two different discrimination cases: falls versus ADLs (i.e., excluding near-falls) and falls versus non-falls (i.e., including near-falls). Our experiment results show that both methods produce similar accuracies for the fall versus ADL detection case; however, Method 1 exhibits a much higher accuracy than Method 2 for the fall versus non-fall detection case. This result demonstrates the superiority of the vertical velocity over the peak acceleration as a fall detection parameter when the near-fall conditions are included in the non-fall category, in addition to its capability of detecting pre-impact falls.
尽管险些跌倒（或可恢复的失衡）对许多老年人来说是常见的情况，但它们很少受到关注，并且在以前基于实验室的跌倒评估中未被考虑。因此，本文除了关注典型的跌倒和日常生活活动（ADL）外，还探讨了险些跌倒的情况。首先，提出了一种基于垂直速度的新型撞击前跌倒检测方法，该方法使用可穿戴惯性传感器。其次，为了研究险些跌倒情况对作为跌倒检测参数的垂直速度的检测性能和可行性的影响，通过将所提出的方法（方法1）与基于加速度的方法（方法2）在以下两种不同的判别情况下进行比较，来评估所提出方法的检测性能：跌倒与ADL（即排除险些跌倒）以及跌倒与非跌倒（即包括险些跌倒）。我们的实验结果表明，对于跌倒与ADL检测情况，两种方法产生的准确率相似；然而，对于跌倒与非跌倒检测情况，方法1的准确率比方法2高得多。这一结果表明，当险些跌倒情况被纳入非跌倒类别时，垂直速度作为跌倒检测参数优于峰值加速度，此外它还具有检测撞击前跌倒的能力。
