scholarly journals Rotational Acceleration Measurements - Evaluating Helmet Protection

2004 ◽  
Vol 31 (4) ◽  
pp. 499-503 ◽  
Author(s):  
M. Kis ◽  
F. Saunders ◽  
M.W. ten Hove ◽  
J.R. Leslie
Keyword(s):  
Horizontal Plane ◽  
Rotational Acceleration ◽  
Testing Device ◽  
Cerebral Concussion ◽  
Impact Simulation ◽  
Head Protection ◽  
Rotational Components ◽  
Protection Devices ◽  
Testing Standards ◽  
Testing Paradigm

Purpose:Current helmet testing standards do not address the rotational components of an impact to the head. We describe a new testing paradigm used to measure the rotational acceleration of a headform and a protective helmet following an impact to the head in the horizontal plane. This impact simulation allows for the testing of currently available head protection devices in conditions thought to be important for the generation of cerebral concussion. The degree to which a particular helmet dampens rotational acceleration, and thus protects against concussion, can be assessed.Methods:Our testing device consists of a pneumatic piston that provides a measured impact to a standard headform. Four different helmets were tested using the described paradigm.Results:Acceleration curves for each helmet and the corresponding headform are presented.Conclusion:Clear differences in rotational acceleration were demonstrated. Possible avenues of further investigation are discussed.

Predicting the effect of hearing-protection devices on horizontal-plane sound localization

2021 ◽  
Vol 150 (4) ◽  
pp. A340-A340
Author(s):  
Nathaniel J. Spencer ◽  
Zachariah N. Ennis ◽  
Natalie Jackson ◽  
Brian D. Simpson ◽  
Eric R. Thompson
Keyword(s):  
Sound Localization ◽  
Horizontal Plane ◽  
Hearing Protection ◽  
Plane Sound ◽  
Protection Devices

The development of a threshold curve for the understanding of concussion in sport

Trauma ◽  
2016 ◽  
Vol 19 (3) ◽  
pp. 196-206 ◽  
Author(s):  
T Blaine Hoshizaki ◽  
Andrew Post ◽  
Marshall Kendall ◽  
Janie Cournoyer ◽  
Philippe Rousseau ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Narrow Range ◽  
Rotational Acceleration ◽  
Threshold Curve ◽  
Head Protection ◽  
Hybrid Iii ◽  
Tolerance Curve ◽  
Minor Traumatic Brain Injury ◽  
Standard Development

Much of what is known concerning human brain injury thresholds is based upon impacts to cadavers and animal models that were used to generate the Wayne State Concussion Tolerance Curve (WSTC) and similar curves. These curves are the foundation for predictive metrics used in standard development as well as helmet design. These curves were based upon a very narrow range of impacts; impacts whose characteristics differ greatly from how the head is impacted in sport. This research examines the uses of time-based curves like the WSTC in the context of understanding mechanisms of brain injury and head protection. Published linear/rotational acceleration magnitude/duration data from Hybrid III laboratory reconstructions of brain injury events were plotted. This research further develops the understanding of injury thresholds in comparison to threshold curves such as the WSTC and Brain Injury Curve Leuven. The data demonstrate the relationships between magnitude and duration of dynamic response on minor traumatic brain injury (mTBI) in sport.

Effect of Hearing and Head Protection on the Localization of Tonal and Broadband Reverse Alarms

2021 ◽  
pp. 001872082199222
Author(s):  
Chantal Laroche ◽  
Christian Giguère ◽  
Véronique Vaillancourt ◽  
Claudia Marleau ◽  
Marie-France Cadieux ◽  
...  
Keyword(s):  
Sound Localization ◽  
Background Noise ◽  
Construction Safety ◽  
Tablet Computer ◽  
Hearing Protection ◽  
Minimal Effect ◽  
Heavy Vehicles ◽  
Single Cycle ◽  
Head Protection ◽  
Protection Devices

Objective This study explored the effects of hearing protection devices (HPDs) and head protection on the ability of normal-hearing individuals to localize reverse alarms in background noise. Background Among factors potentially contributing to accidents involving heavy vehicles, reverse alarms can be difficult to localize in space, leading to errors in identifying the source of danger. Previous studies have shown that traditional tonal alarms are more difficult to localize than broadband alarms. In addition, HPDs and safety helmets may further impair localization. Method Standing in the middle of an array of eight loudspeakers, participants with and without HPDs (passive and level-dependent) had to identify the loudspeaker emitting a single cycle of the alarm while performing a task on a tablet computer. Results The broadband alarm was easier to localize than the tonal alarm. Passive HPDs had a significant impact on sound localization (earmuffs generally more so than earplugs), particularly double hearing protection, and level-dependent HPDs did not fully restore sound localization abilities. The safety helmet had a much lesser impact on performance than HPDs. Conclusion Where good sound localization abilities are essential in noisy workplaces, the broadband alarm should be used, double hearing protection should be avoided, and earplug-style passive or level-dependent devices may be a better choice than earmuff-style devices. Construction safety helmets, however, seem to have only a minimal effect on sound localization. Application Results of this study will help stakeholders make decisions that are more informed in promoting safer workplaces.

Determination of the International Sensitivity Index of a New Near-Patient Testing Device to Monitor Oral Anticoagulant Therapy

1997 ◽  
Vol 78 (02) ◽  
pp. 855-858 ◽  
Author(s):  
Armando Tripodi ◽  
Veena Chantarangkul ◽  
Marigrazia Clerici ◽  
Barbara Negri ◽  
Pier Mannuccio Mannucci
Keyword(s):  
Linear Relationship ◽  
Whole Blood ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
Oral Anticoagulants ◽  
Calibration Model ◽  
Testing Device ◽  
Data Points ◽  
Near Patient Testing

SummaryA key issue for the reliable use of new devices for the laboratory control of oral anticoagulant therapy with the INR is their conformity to the calibration model. In the past, their adequacy has mostly been assessed empirically without reference to the calibration model and the use of International Reference Preparations (IRP) for thromboplastin. In this study we reviewed the requirements to be fulfilled and applied them to the calibration of a new near-patient testing device (TAS, Cardiovascular Diagnostics) which uses thromboplastin-containing test cards for determination of the INR. On each of 10 working days citrat- ed whole blood and plasma samples were obtained from 2 healthy subjects and 6 patients on oral anticoagulants. PT testing on whole blood and plasma was done with the TAS and parallel testing for plasma by the manual technique with the IRP CRM 149S. Conformity to the calibration model was judged satisfactory if the following requirements were met: (i) there was a linear relationship between paired log-PTs (TAS vs CRM 149S); (ii) the regression line drawn through patients data points, passed through those of normals; (iii) the precision of the calibration expressed as the CV of the slope was <3%. A good linear relationship was observed for calibration plots for plasma and whole blood (r = 0.98). Regression lines drawn through patients data points, passed through those of normals. The CVs of the slope were in both cases 2.2% and the ISIs were 0.965 and 1.000 for whole blood and plasma. In conclusion, our study shows that near-patient testing devices can be considered reliable tools to measure INR in patients on oral anticoagulants and provides guidelines for their evaluation.

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