Experimental Investigation of Friction Between Vehicle Air Bag Material and Head Skin for Humans and Crash Test Dummies

2020 ◽  
Author(s):  
Sheng Dong ◽  
Yun-Seok Kang ◽  
John Bolte ◽  
Jason Stammen ◽  
Kevin Moorhouse
Keyword(s):  
Friction Coefficient ◽  
Human Skin ◽  
Brain Injuries ◽  
Motor Vehicle ◽  
Experimental Testing ◽  
Crash Test ◽  
Skin Sample ◽  
Air Bags ◽  
Air Bag ◽  
Skin Samples

Abstract Motor vehicle crashes can produce serious head or brain injuries due to contact with interior vehicle structures. It has been found through both field data analysis and experimental testing that many of these brain injuries occur in oblique crashes, even with the deployment of air bags. Research has determined that rotational head velocity is strongly correlated to the risk of brain injury through metrics such as Brain Rotational Injury Criteria (BrIC). The severity of rotational head motion could be related to the friction force developed during contact between the head and air bags. Although crash test dummy head skins are designed with appropriate mass properties and anthropometry as well as material type and thickness to emulate the proper impact response of the human head, it is not known whether they accurately represent the frictional properties of human skin during air bag interaction. This study experimentally characterized the friction coefficient between human skin and air bag fabrics using a pin-on-disc tribometer. Skin samples were harvested from different locations (forehead, cheeks, chin) from specimens of post-mortem human subjects (PMHS). Fabric samples were cut from six different air bags spanning various vehicle manufacturers and interior mounting locations. For comparison, four types of dummy head skin samples were also tested against the air bag samples. Friction was measured between different skinair bag material combinations at various linear velocities and normal forces. It was determined that the difference between human and dummy skin friction with the air bag samples varied significantly among different air bags; however, the effect of linear speed, normal force, and human skin sample harvesting location on friction coefficient is negligible. Except for one air bag fabric, the friction coefficients of the dummy skin are higher than those quantified for human skin.

The continued burden of spine fractures after motor vehicle crashes

2009 ◽  
Vol 10 (2) ◽  
pp. 86-92 ◽  
Author(s):  
Marjorie C. Wang ◽  
Frank Pintar ◽  
Narayan Yoganandan ◽  
Dennis J. Maiman
Keyword(s):  
Motor Vehicle ◽  
Seat Belt ◽  
Motor Vehicle Crashes ◽  
Spine Fracture ◽  
Spine Fractures ◽  
Seat Belts ◽  
Front Seat ◽  
Air Bags ◽  
Police Reports ◽  
Air Bag

Object Spine fractures are a significant cause of morbidity and mortality after motor vehicle crashes (MVCs). Public health interventions, such as the National Highway Traffic Safety Administration's Federal Motor Vehicle Safety Standards, have led to an increase in automobiles with air bags and the increased use of seat belts to lessen injuries sustained from MVCs. The purpose of this study was to evaluate secular trends in the occurrence of spine fractures associated with MVCs and evaluate the association between air bag and seat belt use with spine fractures. Methods Using the Crash Outcome Data Evaluation System, a database of the police reports of all MVCs in Wisconsin linked to hospital records, the authors studied the occurrence of spine fractures and seat belt and air bag use from 1994 to 2002. Demographic information and crash characteristics were obtained from the police reports. Injury characteristics were determined using International Classification of Disease, 9th Revision, Clinical Modification (ICD-9-CM) hospital discharge codes. Results From 1994 to 2002, there were 29,860 hospital admissions associated with automobile or truck crashes. There were 20,276 drivers or front-seat passengers 16 years of age and older who were not missing ICD-9-CM discharge codes, seat belt or air bag data, and who had not been ejected from the vehicle. Of these, 2530 (12.5%) sustained a spine fracture. The occurrence of spine fractures increased over the study period, and the use of a seat belt plus air bag, and of air bags alone also increased during this period. However, the occurrence of severe spine fractures (Abbreviated Injury Scale Score ≥3) did not significantly increase over the study period. The use of both seat belt and air bag was associated with decreased odds of a spine fracture. Use of an air bag alone was associated with increased odds of a severe thoracic, but not cervical spine fracture. Conclusions Among drivers and front-seat passengers admitted to the hospital after MVCs, the occurrence of spine fractures increased from 1994 to 2002 despite concomitant increases in seat belt and air bag use. However, the occurrence of severe spine fractures did not increase over the study period. The use of both seat belt and air bag is protective against spine fractures. Although the overall increased occurrence of spine fractures may appear contrary to the increased use of seat belts and air bags in general, it is possible that improved imaging technology may be associated with an increase in the diagnosis of relatively minor fractures. However, given the significant protective effects of both seat belt and air bag use against spine fractures, resources should continue to be dedicated toward increasing their use to mitigate the effects of MVCs.

Letters to the Editor

PEDIATRICS ◽  
1981 ◽  
Vol 68 (4) ◽  
pp. 613-613
Author(s):  
Allan F. Williams
Keyword(s):  
General Motors ◽  
American Population ◽  
Letters To The Editor ◽  
Air Bags ◽  
Crash Protection ◽  
Air Bag ◽  
Conducting Research

Dr Beuf's comment that air bags "can be more hazard than help" to children is incorrect. The concern had been expressed that some unrestrained children in crashes would be in positions in which they would be contacted by an air bag early in its deployment, and possibly injured as a result. Some years ago both Volvo and General Motors raised this issue after conducting research using pigs as child surrogates. Volvo cautioned, however, that "it would be extremely unfortunate if either government or industry allows the emotionality of the standing child/inflatable restraint issue to overshadow the potential that such systems have for preventing fatalities and injuries in a much larger segment of the American population" (letter submitted to Docket 74-14; Notice 1-FMVSS208, Occupant Crash Protection, Oct 18, 1974).

Capturing Age-Dependent Properties of Human Skin Using Magnetorheological Elastomers

2018 ◽  
Author(s):  
Kyle Weaver ◽  
Jeong-Hoi Koo ◽  
Tae-Heon Yang ◽  
Young-Min Kim
Keyword(s):  
Mechanical Properties ◽  
Human Skin ◽  
Skin Testing ◽  
Filler Particle ◽  
Variable Stiffness ◽  
Particle Volume ◽  
Magnetorheological Elastomers ◽  
Age Dependent ◽  
Skin Samples

Artificial and synthetic skins are widely used in the medical field; used in applications ranging from skin grafts to suture training pads. There is a growing need for artificial skins with tunable properties. However, current artificial skins do not take into account the variability of mechanical properties between individual humans as well as the age-dependent properties of human skin. Furthermore, there has been little development in artificial skins based on these properties. Thus, the primary purpose of this research is to develop variable stiffness artificial skin samples using magnetorheological elastomers (MREs) whose properties that can be controlled using external magnetic fields. In this study, multiple MRE skin samples were fabricated with varying filler particle volume contents. Using a precision dynamic mechanical analyzer, a series of indenting experiments were performed on the samples to characterize their mechanical properties. The samples were tested using a spherical indenter that indented a total depth of 1 mm with a speed of 0.01 mm/s and unloaded at the same rate. The results show that the modulus or stiffness increases significantly as the iron percent (w/w) in the sample increases. Additionally, the stiffness of the sample increases proportional to the intensity of the applied external magnetic field. To assess the MRE samples’ variability of properties, the testing results were compared with in vivo human skin testing data. The results show the MRE samples are feasible to represent the age-dependent stiffness demonstrated in in vivo human skin testing. The MRE materials studied will be further studied as a variable-stiffness skin model in medical devices, such as radial pulse simulators.

scholarly journals A Laboratory Method to Measure Skin Surface Staining by Cigarette Smoke, Tobacco Heating Products and E-Cigarettes

2021 ◽  
Vol 30 (4) ◽  
pp. 158-166
Author(s):  
Annette Dalrymple ◽  
Emma-Jayne Bean ◽  
Jesse Thissen ◽  
Holger Behrsing ◽  
Steven Coburn ◽  
...  
Keyword(s):  
Cigarette Smoke ◽  
Skin Surface ◽  
Laboratory Method ◽  
Porcine Skin ◽  
Skin Sample ◽  
Side Stream ◽  
Air Control ◽  
And Control ◽  
Skin Samples

Summary Exhaled or side-stream cigarette smoke (CS) may visually stain a consumer's skin over time. Tobacco heating products (THPs) and e-cigarettes (ECs) have reduced staining potential because they do not produce side-stream aerosols and their exhaled aerosols have significantly reduced levels of toxicants, particles and odour. Here we assess discolouration of porcine skin in vitro after exposure to particulate matter (PM) or aerosols from CS (3R4F), two THPs (glo and glo sens) and an EC (iSwitch Maxx). PM was prepared by capturing aerosols on Cambridge filter pads and eluting with dimethyl sulfoxide (DMSO). Abattoir-obtained porcine skin samples were incubated with PM or DMSO control at 37 °C between 0 and 6.0 h. For aerosol assessment, porcine skin samples were exposed to between 50 and 400 puffs of the products, or air control, using a smoking machine. Colour profiles and staining levels of each skin sample were measured at different timepoints and puff thresholds using a spectrophotometer. Staining increased with time and dose, the greatest changes being observed following exposure to aerosols and PM from CS. THP, EC and control values were significantly different from CS after 0.5 h exposure to PM or 50 puffs of aerosols. The minimal staining induced by THPs and EC was comparable to controls. These data suggest that THPs and ECs could offer hygiene benefits to consumers who switch from smoking cigarettes. Further studies are required to assess the longer-term effects of THPs and ECs on skin discoloration. [Contrib. Tob. Nicotine Res. 30 (2021) 158–166]

Door Latch Failure Risk Identification Using Virtual Testing Methods

2017 ◽  
Vol 4 (3) ◽  
Author(s):  
Keith Friedman ◽  
Khanh Bui ◽  
John Hutchinson
Keyword(s):  
Motor Vehicle ◽  
Performance Testing ◽  
Risk Identification ◽  
Side Impact ◽  
Crash Test ◽  
Loading Conditions ◽  
Passenger Vehicle ◽  
Virtual Testing ◽  
Side Door ◽  
Failure Loads

Vehicle door latch performance testing presently utilizes uniaxial quasi-static loading conditions. Current technology enables sophisticated virtual testing of a broad range of systems. Door latch failures have been observed in vehicles under a variety of conditions. Typically, these conditions involve multi-axis loading conditions. The loading conditions presented during rollovers on passenger vehicle side door latches have not been published. Rollover crash test results, rollover crashes, and physical Federal Motor Vehicle Safety Standard (FMVSS) 206 latch testing results are reviewed. The creation and validation of a passenger vehicle door latch model is described. The multi-axis loading conditions observed in virtual rollover testing at the latch location are characterized and applied to the virtual testing of a latch in the secondary latch position. The results are then compared with crash test and real world rollover results for the same latch. The results indicate that a door latch that meets the secondary latch position requirements may fail at loads substantially below the FMVSS 206 uniaxial failure loads. In the side impact mode, risks associated with door handle designs and the potential for inertial release can be considered prior to manufacturing with virtual testing. An example case showing the effects of material and spring selection illustrates the potential issues that can be detected in advance of manufacturing. The findings suggest the need for re-examining the relevance of existing door latch testing practices in light of the prevalence of rollover impacts and other impact conditions in today's vehicle fleet environment.

Does Alcohol Intoxication Protect Patients from Severe Injury and Reduce Hospital Mortality? The Association of Alcohol Consumption with the Severity of Injury and Survival in Trauma Patients

2013 ◽  
Vol 79 (12) ◽  
pp. 1289-1294 ◽  
Author(s):  
Chi-Hsun Hsieh ◽  
Li-Ting Su ◽  
Yu-Chun Wang ◽  
Chih-Yuan Fu ◽  
Hung-Chieh Lo ◽  
...  
Keyword(s):  
Alcohol Consumption ◽  
Hospital Stay ◽  
Brain Injuries ◽  
Injury Severity ◽  
Motor Vehicle ◽  
Length Of Hospital Stay ◽  
Trauma Patients ◽  
Prolonged Hospital Stay ◽  
Severe Injuries ◽  
Prolonged Hospital

Alcohol-related motor vehicle collisions are a major cause of mortality in trauma patients. This prospective observational study investigated the influence of antecedent alcohol use on outcomes in trauma patients who survived to reach the hospital. From 2005 to 2011, all patients who were older than 18 years and were admitted as a result of motor vehicle crashes were included. Blood alcohol concentration (BAC) was routinely measured for each patient on admission. Patients were divided into four groups based on their BAC level, which included nondrinking, BAC less than 100, BAC 100 to 200, and BAC 200 mg/dL or greater. Patient demographics, physical status and injury severity on admission, length of hospital stay, and outcome were compared between the groups. Odds ratios of having a severe injury, prolonged hospital stay, and mortality were estimated. Patients with a positive BAC had an increased risk of sustaining craniofacial and thoracoabdominal injuries. Odds ratios of having severe injuries (Injury Severity Score [ISS] 16 or greater) and a prolonged hospital stay were also increased. However, for those patients whose ISS was 16 or greater and who also had a brain injury, risk of fatality was significantly reduced if they were intoxicated (BAC 200 mg/dL or greater) before injury. Alcohol consumption does not protect patients from sustaining severe injuries nor does it shorten the length of hospital stay. However, there were potential survival benefits related to alcohol consumption for patients with brain injuries but not for those without brain injuries. Additional research is required to investigate the mechanism of this association further.

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