Search results for "Accelerometer."
showing 10 items of 183 documents
The Positive Relationship between Moderate-to-Vigorous Physical Activity and Bone Mineral Content Is Not Mediated by Free Leptin Index in Prepubertal…
2021
Purpose: Moderate-to-vigorous physical activity (MVPA) positively influences bone mineral content (BMC) in prepubertal children, but it is unknown whether this relationship is partially mediated by free leptin index. The aim of this study was to examine whether the relationship between MVPA and total body less head (TBLH) BMC is mediated or moderated by free leptin index in prepubertal children. Methods: We performed a cross-sectional analysis on 401 children (194 girls) from baseline examinations of the Physical Activity and Nutrition in Childhood Study. We applied the four-way decomposition mediation analysis method to assess whether free leptin index, measured from fasted blood samples, …
Instrumentation in sports biomechanics
2007
La biomecánica deportiv emplea una serie de herramientas y técnicas de instrumentación paara el análisis de las diferentes disciplinas físico-deportivas, así como también para el desarrollo de nuevos materiales y equipamiento deportivo. Sin embargo, estas herramientas empleadas actualmente, poseen su cuerpo de conocimientos teóricos en los conocidos como "precursores de la biomecánica". Aristóteles, Da Vinci, Galileo, Descartes, Borelli, Newton, etc... El documento, presenta diferentes técnicas instrumentales desarrolladas para evaluar y aportar información relevante en la ejecución físico-deportiva, así como contribuir en la disminución de la epidemiología deportiva. Entre las principales …
Adaptive neural-fuzzy inference system based method to modeling of vehicle crash
2013
Various areas of research need to be considered in order to establish a mathematical model of a vehicle crash. To enhance the modeling process, a novel ANFIS-based approach to reconstruct behavior of impacting vehicles is presented in this paper. Kinematics of center of gravity (COG) a vehicle involved in an oblique barrier collision is reproduced by application of a five-layered ANFIS structure. Then, the same ANFIS system is used to simulate a different collision type than the one which was used in the training stage. The points of interests are selected to be the locations of accelerometers mounting. The accuracy of the proposed method is evaluated by the comparative analysis with the re…
The Use of Accelerometers and Gyroscopes to Estimate Hip and Knee Angles on Gait Analysis
2014
In this paper the performance of a sensor system, which has been developed to estimate hip and knee angles and the beginning of the gait phase, have been investigated. The sensor system consists of accelerometers and gyroscopes. A new algorithm was developed in order to avoid the error accumulation due to the gyroscopes drift and vibrations due to the ground contact at the beginning of the stance phase. The proposed algorithm have been tested and compared to some existing algorithms on over-ground walking trials with a commercial device for assisted gait. The results have shown the good accuracy of the angles estimation, also in high angle rate movement.
A Multi-Position Calibration Method for Consumer-Grade Accelerometers, Gyroscopes, and Magnetometers to Field Conditions
2017
This paper presents a calibration method for consumer-grade accelerometers, gyroscopes, and magnetometers. Considering the calibration of consumer-grade sensors, it is essential that no specialized equipment is required to create reference signals. In addition, the less is required from the reference signals, the more suitable the method is on the field. In the proposed method, the novelty in the calibration of the gyroscopes lies in the exploitation of only the known net rotations between the positions in a multi-position calibration. For accelerometers and magnetometers, the innovation is that the direction of reference signals, the gravity and the magnetic field of the Earth, are estimat…
Real time assessment of hand-arm vibration system based on capacitive MEMS accelerometers
2012
Vibrations are a well known potential cause of health diseases and therefore constitute a main concern for the safety of workers in a large number of activities. In order to prevent health hazards, national and international institutions have issued laws and directives which establish recommended limits to the workers' exposure to vibrations during operations. Consequently, if the amount of adsorbed vibration exceeds the allowable daily limits the worker has to stop his job. Recent wireless sensing and communicating technologies can effectively be employed for such purpose, allowing to develop monitoring customized devices at affordable cost which could be easily employed during the workers…
The harp: a vehicle crash test apparatus for full-scale crash test experiments
2012
Published version of an article in the journal: The International Journal of Advanced Manufacturing Technology. Also available from the publisher at: http://dx.doi.org/10.1007/s00170-012-3960-3 The current paper describes an apparatus for full-scale vehicle crash test experimentation. This apparatus is referred to as the harp. In brief, the harp may either accelerate a trolley which is impacted into a test vehicle or the test vehicle itself may be accelerated and impacted into an object such as a barrier, a pole, or another vehicle. If a trolley is accelerated, it is equipped with load cells to record the axial crushing force. If a test vehicle is accelerated, it is equipped with a three-ax…
Deep Learning for Classifying Physical Activities from Accelerometer Data
2021
Physical inactivity increases the risk of many adverse health conditions, including the world’s major non-communicable diseases, such as coronary heart disease, type 2 diabetes, and breast and colon cancers, shortening life expectancy. There are minimal medical care and personal trainers’ methods to monitor a patient’s actual physical activity types. To improve activity monitoring, we propose an artificial-intelligence-based approach to classify the physical movement activity patterns. In more detail, we employ two deep learning (DL) methods, namely a deep feed-forward neural network (DNN) and a deep recurrent neural network (RNN) for this purpose. We evaluate the proposed models on two phy…
WiWeHAR: Multimodal Human Activity Recognition Using Wi-Fi and Wearable Sensing Modalities
2020
Robust and accurate human activity recognition (HAR) systems are essential to many human-centric services within active assisted living and healthcare facilities. Traditional HAR systems mostly leverage a single sensing modality (e.g., either wearable, vision, or radio frequency sensing) combined with machine learning techniques to recognize human activities. Such unimodal HAR systems do not cope well with real-time changes in the environment. To overcome this limitation, new HAR systems that incorporate multiple sensing modalities are needed. Multiple diverse sensors can provide more accurate and complete information resulting in better recognition of the performed activities. This article…
Definitions, measurement and prevalence of sedentary behaviour in adults with intellectual disabilities – a systematic review
2017
Supporting positive change in lifestyle behaviours is a priority in tackling the health inequalities experienced by adults with intellectual disabilities. In this systematic review, we examine the evidence on the definition, measurement and epidemiology of sedentary behaviour of adults with intellectual disabilities. A systematic literature search of PUBMED, EMBASE, MEDLINE and Google Scholar was performed to identify studies published from 1990 up to October 2015. Nineteen papers met the criteria for inclusion in the systematic review. Many researchers do not distinguish between insufficient physical activity and sedentary behaviour. None of the studies reported the reliability and validit…