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Exploration and Implementation of a Pre-Impact Fall Recognition Method Based on an Inertial Body Sensor Network

The unintentional injuries due to falls in elderly people give rise to a multitude of health and economic problems due to the growing aging population. The use of early pre-impact fall alarm and self-protective control could greatly reduce fall injuries. This paper aimed to explore and implement a p...

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Autores principales: Zhao, Guoru, Mei, Zhanyong, Liang, Ding, Ivanov, Kamen, Guo, Yanwei, Wang, Yongfeng, Wang, Lei
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Molecular Diversity Preservation International (MDPI) 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3522966/
https://www.ncbi.nlm.nih.gov/pubmed/23202213
http://dx.doi.org/10.3390/s121115338
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author Zhao, Guoru
Mei, Zhanyong
Liang, Ding
Ivanov, Kamen
Guo, Yanwei
Wang, Yongfeng
Wang, Lei
author_facet Zhao, Guoru
Mei, Zhanyong
Liang, Ding
Ivanov, Kamen
Guo, Yanwei
Wang, Yongfeng
Wang, Lei
author_sort Zhao, Guoru
collection PubMed
description The unintentional injuries due to falls in elderly people give rise to a multitude of health and economic problems due to the growing aging population. The use of early pre-impact fall alarm and self-protective control could greatly reduce fall injuries. This paper aimed to explore and implement a pre-impact fall recognition/alarm method for free-direction fall activities based on understanding of the pre-impact lead time of falls and the angle of body postural stability using an inertial body sensor network. Eight healthy Asian adult subjects were arranged to perform three kinds of daily living activities and three kinds of fall activities. Nine MTx sensor modules were used to measure the body segmental kinematic characteristics of each subject for pre-impact fall recognition/alarm. Our analysis of the kinematic features of human body segments showed that the chest was the optimal sensor placement for an early pre-impact recognition/alarm (i.e., prediction/alarm of a fall event before it happens) and post-fall detection (i.e., detection of a fall event after it already happened). Furthermore, by comparative analysis of threshold levels for acceleration and angular rate, two acceleration thresholds were determined for early pre-impact alarm (7 m/s/s) and post-fall detection (20 m/s/s) under experimental conditions. The critical angles of postural stability of torso segment in three kinds of fall activities (forward, sideway and backward fall) were determined as 23.9 ± 3.3, 49.9 ± 4.1 and 9.9 ± 2.5 degrees, respectively, and the relative average pre-impact lead times were 329 ± 21, 265 ± 35 and 257 ± 36 ms. The results implied that among the three fall activities the sideway fall was associated with the largest postural stability angle and the forward fall was associated with the longest time to adjust body angle to avoid the fall; the backward fall was the most difficult to avoid among the three kinds of fall events due to the toughest combination of shortest lead time and smallest angle of postural stability which made it difficult for the self-protective control mechanism to adjust the body in time to avoid falling down.
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spelling pubmed-35229662013-01-09 Exploration and Implementation of a Pre-Impact Fall Recognition Method Based on an Inertial Body Sensor Network Zhao, Guoru Mei, Zhanyong Liang, Ding Ivanov, Kamen Guo, Yanwei Wang, Yongfeng Wang, Lei Sensors (Basel) Article The unintentional injuries due to falls in elderly people give rise to a multitude of health and economic problems due to the growing aging population. The use of early pre-impact fall alarm and self-protective control could greatly reduce fall injuries. This paper aimed to explore and implement a pre-impact fall recognition/alarm method for free-direction fall activities based on understanding of the pre-impact lead time of falls and the angle of body postural stability using an inertial body sensor network. Eight healthy Asian adult subjects were arranged to perform three kinds of daily living activities and three kinds of fall activities. Nine MTx sensor modules were used to measure the body segmental kinematic characteristics of each subject for pre-impact fall recognition/alarm. Our analysis of the kinematic features of human body segments showed that the chest was the optimal sensor placement for an early pre-impact recognition/alarm (i.e., prediction/alarm of a fall event before it happens) and post-fall detection (i.e., detection of a fall event after it already happened). Furthermore, by comparative analysis of threshold levels for acceleration and angular rate, two acceleration thresholds were determined for early pre-impact alarm (7 m/s/s) and post-fall detection (20 m/s/s) under experimental conditions. The critical angles of postural stability of torso segment in three kinds of fall activities (forward, sideway and backward fall) were determined as 23.9 ± 3.3, 49.9 ± 4.1 and 9.9 ± 2.5 degrees, respectively, and the relative average pre-impact lead times were 329 ± 21, 265 ± 35 and 257 ± 36 ms. The results implied that among the three fall activities the sideway fall was associated with the largest postural stability angle and the forward fall was associated with the longest time to adjust body angle to avoid the fall; the backward fall was the most difficult to avoid among the three kinds of fall events due to the toughest combination of shortest lead time and smallest angle of postural stability which made it difficult for the self-protective control mechanism to adjust the body in time to avoid falling down. Molecular Diversity Preservation International (MDPI) 2012-11-08 /pmc/articles/PMC3522966/ /pubmed/23202213 http://dx.doi.org/10.3390/s121115338 Text en © 2012 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Article
Zhao, Guoru
Mei, Zhanyong
Liang, Ding
Ivanov, Kamen
Guo, Yanwei
Wang, Yongfeng
Wang, Lei
Exploration and Implementation of a Pre-Impact Fall Recognition Method Based on an Inertial Body Sensor Network
title Exploration and Implementation of a Pre-Impact Fall Recognition Method Based on an Inertial Body Sensor Network
title_full Exploration and Implementation of a Pre-Impact Fall Recognition Method Based on an Inertial Body Sensor Network
title_fullStr Exploration and Implementation of a Pre-Impact Fall Recognition Method Based on an Inertial Body Sensor Network
title_full_unstemmed Exploration and Implementation of a Pre-Impact Fall Recognition Method Based on an Inertial Body Sensor Network
title_short Exploration and Implementation of a Pre-Impact Fall Recognition Method Based on an Inertial Body Sensor Network
title_sort exploration and implementation of a pre-impact fall recognition method based on an inertial body sensor network
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3522966/
https://www.ncbi.nlm.nih.gov/pubmed/23202213
http://dx.doi.org/10.3390/s121115338
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