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Sensor orientation and other factors which increase the blast overpressure reporting errors

This study compared the response of the wearable sensors tested against the industry-standard pressure transducers at blast overpressure (BOP) levels typically experienced in training. We systematically evaluated the effects of the sensor orientation with respect to the direction of the incident sho...

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Autores principales: Misistia, Anthony, Skotak, Maciej, Cardenas, Arturo, Alay, Eren, Chandra, Namas, Kamimori, Gary H.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7544144/
https://www.ncbi.nlm.nih.gov/pubmed/33031423
http://dx.doi.org/10.1371/journal.pone.0240262
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author Misistia, Anthony
Skotak, Maciej
Cardenas, Arturo
Alay, Eren
Chandra, Namas
Kamimori, Gary H.
author_facet Misistia, Anthony
Skotak, Maciej
Cardenas, Arturo
Alay, Eren
Chandra, Namas
Kamimori, Gary H.
author_sort Misistia, Anthony
collection PubMed
description This study compared the response of the wearable sensors tested against the industry-standard pressure transducers at blast overpressure (BOP) levels typically experienced in training. We systematically evaluated the effects of the sensor orientation with respect to the direction of the incident shock wave and demonstrated how the averaging methods affect the reported pressure values. The evaluated methods included averaging peak overpressure and impulse of all four sensors mounted on a helmet, taking the average of the three sensors, or isolating the incident pressure equivalent using two sensors. The experimental procedures were conducted in controlled laboratory conditions using the shock tube, and some of the findings were verified in field conditions with live fire charges during explosive breaching training. We used four different orientations (0°, 90°, 180°, and 270°) of the headform retrofitted with commonly fielded helmets (ACH, ECH, Ops-Core) with four B3 Blast Gauge sensors. We determined that averaging the peak overpressure values overestimates the actual dosage experienced by operators, which is caused by the reflected pressure contribution. This conclusion is valid despite the identified limitation of the B3 gauges that consistently underreport the peak reflected overpressure, compared to the industry-standard sensors. We also noted consistent overestimation of the impulse. These findings demonstrate that extreme caution should be exercised when interpreting occupational blast exposure results without knowing the orientation of the sensors. Pure numerical values without the geometrical, training-regime specific information such as the position of the sensors, the distance and orientation of the trainee to the source of the blast wave, and weapon system used will inevitably lead to erroneous estimation of the individual and cumulative blast overpressure (BOP) dosages. Considering that the 4 psi (~28 kPa) incident BOP is currently accepted as the threshold exposure safety value, a misinterpretation of exposure level may lead to an inaccurate estimation of BOP at the minimum standoff distance (MSD), or exclusion criteria.
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spelling pubmed-75441442020-10-19 Sensor orientation and other factors which increase the blast overpressure reporting errors Misistia, Anthony Skotak, Maciej Cardenas, Arturo Alay, Eren Chandra, Namas Kamimori, Gary H. PLoS One Research Article This study compared the response of the wearable sensors tested against the industry-standard pressure transducers at blast overpressure (BOP) levels typically experienced in training. We systematically evaluated the effects of the sensor orientation with respect to the direction of the incident shock wave and demonstrated how the averaging methods affect the reported pressure values. The evaluated methods included averaging peak overpressure and impulse of all four sensors mounted on a helmet, taking the average of the three sensors, or isolating the incident pressure equivalent using two sensors. The experimental procedures were conducted in controlled laboratory conditions using the shock tube, and some of the findings were verified in field conditions with live fire charges during explosive breaching training. We used four different orientations (0°, 90°, 180°, and 270°) of the headform retrofitted with commonly fielded helmets (ACH, ECH, Ops-Core) with four B3 Blast Gauge sensors. We determined that averaging the peak overpressure values overestimates the actual dosage experienced by operators, which is caused by the reflected pressure contribution. This conclusion is valid despite the identified limitation of the B3 gauges that consistently underreport the peak reflected overpressure, compared to the industry-standard sensors. We also noted consistent overestimation of the impulse. These findings demonstrate that extreme caution should be exercised when interpreting occupational blast exposure results without knowing the orientation of the sensors. Pure numerical values without the geometrical, training-regime specific information such as the position of the sensors, the distance and orientation of the trainee to the source of the blast wave, and weapon system used will inevitably lead to erroneous estimation of the individual and cumulative blast overpressure (BOP) dosages. Considering that the 4 psi (~28 kPa) incident BOP is currently accepted as the threshold exposure safety value, a misinterpretation of exposure level may lead to an inaccurate estimation of BOP at the minimum standoff distance (MSD), or exclusion criteria. Public Library of Science 2020-10-08 /pmc/articles/PMC7544144/ /pubmed/33031423 http://dx.doi.org/10.1371/journal.pone.0240262 Text en https://creativecommons.org/publicdomain/zero/1.0/ This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 (https://creativecommons.org/publicdomain/zero/1.0/) public domain dedication.
spellingShingle Research Article
Misistia, Anthony
Skotak, Maciej
Cardenas, Arturo
Alay, Eren
Chandra, Namas
Kamimori, Gary H.
Sensor orientation and other factors which increase the blast overpressure reporting errors
title Sensor orientation and other factors which increase the blast overpressure reporting errors
title_full Sensor orientation and other factors which increase the blast overpressure reporting errors
title_fullStr Sensor orientation and other factors which increase the blast overpressure reporting errors
title_full_unstemmed Sensor orientation and other factors which increase the blast overpressure reporting errors
title_short Sensor orientation and other factors which increase the blast overpressure reporting errors
title_sort sensor orientation and other factors which increase the blast overpressure reporting errors
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7544144/
https://www.ncbi.nlm.nih.gov/pubmed/33031423
http://dx.doi.org/10.1371/journal.pone.0240262
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