Journal articles on the topic 'Helmets – Testing'
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Mattei, Tobias A., Brandon J. Bond, Carlos R. Goulart, Chris A. Sloffer, Martin J. Morris, and Julian J. Lin. "Performance analysis of the protective effects of bicycle helmets during impact and crush tests in pediatric skull models." Journal of Neurosurgery: Pediatrics 10, no. 6 (December 2012): 490–97. http://dx.doi.org/10.3171/2012.8.peds12116.
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Object Bicycle accidents are a very important cause of clinically important traumatic brain injury (TBI) in children. One factor that has been shown to mitigate the severity of lesions associated with TBI in such scenarios is the proper use of a helmet. The object of this study was to test and evaluate the protection afforded by a children's bicycle helmet to human cadaver skulls with a child's anthropometry in both “impact” and “crushing” situations. Methods The authors tested human skulls with and without bicycle helmets in drop tests in a monorail-guided free-fall impact apparatus from heights of 6 to 48 in onto a flat steel anvil. Unhelmeted skulls were dropped at 6 in, with progressive height increases until failure (fracture). The maximum resultant acceleration rates experienced by helmeted and unhelmeted skulls on impact were recorded by an accelerometer attached to the skulls. In addition, compressive forces were applied to both helmeted and unhelmeted skulls in progressive amounts. The tolerance in each circumstance was recorded and compared between the two groups. Results Helmets conferred up to an 87% reduction in so-called mean maximum resultant acceleration over unhelmeted skulls. In compression testing, helmeted skulls were unable to be crushed in the compression fixture up to 470 pound-force (approximately 230 kgf), whereas both skull and helmet alone failed in testing. Conclusions Children's bicycle helmets provide measurable protection in terms of attenuating the acceleration experienced by a skull on the introduction of an impact force. Moreover, such helmets have the durability to mitigate the effects of a more rare but catastrophic direct compressive force. Therefore, the use of bicycle helmets is an important preventive tool to reduce the incidence of severe associated TBI in children as well as to minimize the morbidity of its neurological consequences.
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Warnica, Meagan J., Jonathan Park, Gillian Cook, Robert Parkinson, Jack P. Callaghan, and Andrew C. Laing. "The influence of repeated chin bar impacts on the protective properties of full-face mountain biking helmets." Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 230, no. 4 (August 2, 2016): 213–24. http://dx.doi.org/10.1177/1754337115600985.
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Full-face helmets are designed to protect against head and face injuries during downhill and free-ride mountain biking. This study assessed whether multiple impacts and helmet type are related to the protective properties of full-face helmets. A drop tower fitted with a helmeted headform simulated impacts to the chin following a forwards fall. Four models of full-face mountain biking helmets were tested. Three repeated trials were completed for each helmet at four impact velocities. Outcome variables included head injury criterion score, peak force, and peak acceleration. Peak accelerations for all trials were below the 300 g pass/fail criterion used in some testing standards. Multiple impacts reduced helmet protective properties, most noticeably at the higher impact velocities (increases in impact severity measures ranging from 11% to 22% for low and 17% to 49% for higher impact velocities). However, the effects of multiple impacts were smaller than the differences observed across individual helmet types. Helmet protective properties were associated with local chin bar characteristics, most notably chin bar length at higher impact velocities. Towards the goal of reducing overall head/brain injury risk in cyclists, there may be value in complimentary messaging about the importance of repeated impacts and helmet type on the protective properties of downhill mountain biking helmets.
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Feler, Joshua, Adrian A. Maung, Rick O'Connor, Kimberly A. Davis, and Jason Gerrard. "Sex-based differences in helmet performance in bicycle trauma." Journal of Epidemiology and Community Health 75, no. 10 (April 7, 2021): 994–1000. http://dx.doi.org/10.1136/jech-2020-215544.
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ObjectivesTo determine the existence of sex-based differences in the protective effects of helmets against common injuries in bicycle trauma.MethodsIn a retrospective cohort study, we identified patients 18 years or older in the 2017 National Trauma Database presenting after bicycle crash. Sex-disaggregated and sex-combined multivariable logistic regression models were calculated for short-term outcomes that included age, involvement with motor vehicle collision, anticoagulant use, bleeding disorder and helmet use. The sex-combined model included an interaction term for sex and helmet use. The resulting exponentiated model parameter yields an adjusted OR ratio of the effects of helmet use for females compared with males.ResultsIn total, 18 604 patients of average age 48.1 were identified, and 18% were female. Helmet use was greater in females than males (48.0% vs 34.2%, p<0.001). Compared with helmeted males, helmeted females had greater rates of serious head injury (37.7% vs 29.9%, p<0.001) despite less injury overall. In sex-disaggregated models, helmet use reduced odds of intracranial haemorrhage and death in males (p<0.001) but not females. In sex-combined models, helmets conferred to females significantly less odds reduction for severe head injury (p=0.002), intracranial bleeding (p<0.001), skull fractures (p=0.001), cranial surgery (p=0.006) and death (p=0.017). There was no difference for cervical spine fracture.ConclusionsBicycle helmets may offer less protection to females compared with males. The cause of this sex or gender-based difference is uncertain, but there may be intrinsic incompatibility between available helmets and female anatomy and/or sex disparity in helmet testing standards.
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CERNICCHI, ALESSANDRO, UGO GALVANETTO, and ROBIN OLSSON. "VIRTUAL TESTING OF COMPOSITE MOTORCYCLE HELMETS." International Journal of Modern Physics B 22, no. 09n11 (April 30, 2008): 1705–11. http://dx.doi.org/10.1142/s0217979208047298.
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A study about the response of motorcycle helmets to impacts is described in this paper and possible ways to improve current designs are discussed. Firstly, a simple unidimensional model of helmet is analyzed and the main parameters that affect its response are pointed out. Subsequently, the generation and testing of the Finite Element model of a commercially available helmet are described and numerical results are compared to experimental results. Finally, the FE modeled is used to compare different design configurations.
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Rollastin, Boy. "Material Biokomposit Sebagai Material Alternatif Sungkup Helm." Manutech : Jurnal Teknologi Manufaktur 9, no. 01 (May 7, 2019): 6–11. http://dx.doi.org/10.33504/manutech.v9i01.24.
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A Helmet is an equipment that should be used by motorcycle riders. The correct function of helmets is to protect motorcycle riders from head injuries during accident and head collision. Most of helmets existing in markets are produced by helmet factories. Those helmets have to meet certain standards, including the use of materials to construct the helmet lid and the testing processes on the helmet itself. The price of used materials is quite high because those materials are still imported from overseas. It causes the increasing of helmet production cost and the helmet prices in the market become quite expensive. This research aims to find how a biocomposite material (consisting of 85% PP, 10% rice husk and 5% MAPP) can be used as an alternative replacement material for helmet lid preparation. The process is conducted by using finite element software. The result of the testing shows that the test penetration model with 4 mm thickness is not penetrated by indenters. Whereas the result of impact simulation testing of 146.84 g is still classified as a safe limit in accordance with the requirements of SNI 1811-2007 of 300 g.
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Scappaticci, Lorenzo, Giacomo Risitano, Dario Santonocito, Danilo D’Andrea, and Dario Milone. "An Approach to the Definition of the Aerodynamic Comfort of Motorcycle Helmets." Vehicles 3, no. 3 (August 23, 2021): 545–56. http://dx.doi.org/10.3390/vehicles3030033.
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The aim of this work is to obtain a reliable testing methodology for the characterization of the perceived aerodynamic comfort of motorcycle helmets. Attention was paid to the rider’s perception of annoying vibrations induced by wind. In this optic, an experimental comparative campaign was performed in the wind tunnel, testing 16 helmets in two different configurations of neck stiffness. The dataset was collected within a convolutional neural network (CNN or ConvNet) of images, creating a ranking by identifying the best and the worst helmets. The results revealed that each helmet has unique aerodynamic characteristics. Depending on the ranking scale previously created, the aerodynamic comfort of each helmets can be classified within the scale.
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Teng, Tso Liang, Cho Chung Liang, Chien Jong Shih, and Van Hai Nguyen. "Simulation of Bicycle Helmet Impact Test Based on the CPSC Standard." Advanced Materials Research 538-541 (June 2012): 744–47. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.744.
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Bike helmets must meet minimum standards of construction and materials design. This paper focuses on assessment of a helmet based on the shock absorbing test of CPSC’s standard. Computer simulation finite element model is an economical and time-efficient alternative to physical testing. By those compelling reasons, a finite element model of helmeted headform is constructed to serve for development of bicycle helmet technologies. This study performs finite element analyses of helmet impact tests using LS-DYNA software. The linear accelerations at center of gravity of the headform are measured in this simulation. This study implies that the numerical method is a practical approach to helmet design problems. Furthermore, the helmet test model proposed here has potential for guiding the future development of helmet technologies.
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Mattacola, Carl G., Carolina Quintana, Jed Crots, Kimberly I. Tumlin, and Stephanie Bonin. "Repeated Impacts Diminish the Impact Performance of Equestrian Helmets." Journal of Sport Rehabilitation 28, no. 4 (May 1, 2019): 368–72. http://dx.doi.org/10.1123/jsr.2018-0355.
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Context: During thoroughbred races, jockeys are placed in potentially injurious situations, often with inadequate safety equipment. Jockeys frequently sustain head injuries; therefore, it is important that they wear appropriately certified helmets. Objective: The goals of this study are (1) to perform impact attenuation testing according to ASTM F1163-15 on a sample of equestrian helmets commonly used by jockeys in the United States and (2) to quantify headform acceleration and residual crush after repeat impacts at the same location. Participants and Design: Seven helmet models underwent impact attenuation testing according to ASTM F1163-15. A second sample of each helmet model underwent repeat impacts at the crown location for a total of 4 impacts. Setting: Laboratory. Intervention: Each helmet was impacted against a flat and equestrian hazard anvil. Main Outcome Measures: Headform acceleration was recorded during all impact and computed tomography scans were performed preimpact and after impacts 1 and 4 on the crown to quantify liner thickness. Results: Four helmets had 1 impact that exceeded the limit of 300g. During the repeated crown impacts, acceleration remained below 300g for the first and second impacts for all helmets, while only one helmet remained below 300g for all impacts. Foam liner thickness was reduced between 5% and 39% after the first crown impact and between 33% and 70% after the fourth crown impact. Conclusions: All riders should wear a certified helmet and replace it after sustaining a head impact. Following an impact, expanded polystyrene liners compress, and their ability to attenuate head acceleration during subsequent impacts to the same location is reduced. Replacing an impacted helmet may reduce a rider’s head injury risk.
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Rollastin, Boy. "Uji Penetrasi Spesimen Pada Sungkup Helm Berbahan Biokomposit Sebagai Bahan Alternatif Pengganti Helm." Manutech : Jurnal Teknologi Manufaktur 10, no. 01 (May 15, 2019): 9–15. http://dx.doi.org/10.33504/manutech.v10i01.53.
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The correct function of helmets is to protect motorcycle riders from head injuries during accident and head collision. Most of helmets existing in markets are produced by helmet factories. The price of used materials is quite high because those materials are still imported from overseas. It causes the increasing of helmet production cost and the helmet prices in the market become quite expensive. This research aims to find how a biocomposite material (85 % PP, 10 % husk of rice and 5 % MAPP) can be used as an alternative replacement material for helmet lid preparation on the condition of passing the SNI standar test, namely the penetration test. The testing process is carried out by using the test tools referring to SNI 181-2007. The results of penetration test with thickness of 4 mm showed that the speciment can not be penetrated by indenter in accordance with the requirements of SNI 1811-2007. So that the testing can be used as a reference for alternative materials to make a standard helmet lid.
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Bartsch, Adam, Edward Benzel, Vincent Miele, and Vikas Prakash. "Impact test comparisons of 20th and 21st century American football helmets." Journal of Neurosurgery 116, no. 1 (January 2012): 222–33. http://dx.doi.org/10.3171/2011.9.jns111059.
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Object Concussion is the signature American football injury of the 21st century. Modern varsity helmets, as compared with vintage leather helmets, or “leatherheads,” are widely believed to universally improve protection by reducing head impact doses and head injury risk for the 3 million young football players in the US. The object of this study was to compare the head impact doses and injury risks with 11 widely used 21st century varsity helmets and 2 early 20th century leatherheads and to hypothesize what the results might mean for children wearing similar varsity helmets. Methods In an injury biomechanics laboratory, the authors conducted front, oblique front, lateral, oblique rear, and rear head impact tests at 5.0 m/second using helmeted headforms, inducing near- and subconcussive head impact doses on par with approximately the 95th percentile of on-field collision severity. They also calculated impact dose injury risk parameters common to laboratory and on-field traumatic neuromechanics: linear acceleration, angular acceleration, angular velocity, Gadd Severity Index, diffuse axonal injury, acute subdural hematoma, and brain contusion. Results In many instances the head impact doses and head injury risks while wearing vintage leatherheads were comparable to or better than those while wearing several widely used 21st century varsity helmets. Conclusions The authors do not advocate reverting to leather headgear, but they do strongly recommend, especially for young players, instituting helmet safety designs and testing standards, which encourage the minimization of linear and angular impact doses and injury risks in near- and subconcussive head impacts.
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Jamroziak, Krzysztof, Marcin Bajkowski, Miroslaw Bocian, Slawomir Polak, Mariusz Magier, Mariusz Kosobudzki, and Radoslaw Stepien. "Ballistic Head Protection in the Light of Injury Criteria in the Case of the Wz.93 Combat Helmet." Applied Sciences 9, no. 13 (July 2, 2019): 2702. http://dx.doi.org/10.3390/app9132702.
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This paper discusses the general conditions relating to ballistic head protection, analyzing the risks that may occur on contemporary battlefields. A thorough literature review has enabled us to present development trends for helmets used in the largest armies in the world. The authors have focused on impacts to the helmet shell, overloading the entire helmet-protected head–neck system. The main objective of this study is to investigate the protective capability of a helmet shell when subjected to projectile–helmet contact, with contact curvature taken as being an indicator of the impact energy concentration. Blunt head trauma was estimated using backface deformation (BFD). The Wz.93 combat helmet was used for testing. Analytically, dependencies were derived to determine the scope of BFD. A five-parameter model of the helmet piercing process was adopted, thus obtaining the optimal BFD range. Verification of theoretical considerations was carried out on a specially developed research stand. In the ballistic tests, dynamic deflection of the helmet’s body was registered using a speed camera. On the impact testing stand, a fragment of the helmet was pierced, producing results in the low impact velocity range. Data have been presented on the appropriate graph in order to compare them with values specified in the relevant standard and existing literature. Our results correlate well with the norm and literature values.
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Perry, Chris E., John R. Buhrman, and Francis S. Knox. "Biodynamic Testing of Helmet Mounted Systems." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 37, no. 1 (October 1993): 79–83. http://dx.doi.org/10.1177/154193129303700120.
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New helmet mounted visually coupled systems (night vision devices and helmet mounted displays) which are designed to improve pilot performance may only increase the existing potential for neck injury during emergency escape due to the increase in head supported weight and altered center-of-gravity (CG). Designers need criteria for helmet system mass properties which will not increase the risk of injury above acceptable limits. A research study reviewed and analyzed accident statistics, current literature, and in-house laboratory data. Mass properties of various helmet systems were related to biodynamic responses of instrumented humans and manikins from impact tests conducted on the Armstrong Laboratory Vertical Deceleration Tower. Accident data revealed severe neck injuries are relatively rare in an operational setting. Laboratory studies of head/neck biodynamic response relating compression force at the occipital condyles to head supported weight indicate average forces exceed safe guidelines. The studies also suggest that helmet systems weighing less than 2.27 kg and having a center-of-gravity located only slightly above the anatomical axis origin of the head, will not induce severe neck injury during the catapult phase of ejection compared to current operational helmets.
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Lloyd, John, and Frank Conidi. "Brain injury in sports." Journal of Neurosurgery 124, no. 3 (March 2016): 667–74. http://dx.doi.org/10.3171/2014.11.jns141742.
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OBJECT Helmets are used for sports, military, and transportation to protect against impact forces and associated injuries. The common belief among end users is that the helmet protects the whole head, including the brain. However, current consensus among biomechanists and sports neurologists indicates that helmets do not provide significant protection against concussion and brain injuries. In this paper the authors present existing scientific evidence on the mechanisms underlying traumatic head and brain injuries, along with a biomechanical evaluation of 21 current and retired football helmets. METHODS The National Operating Committee on Standards for Athletic Equipment (NOCSAE) standard test apparatus was modified and validated for impact testing of protective headwear to include the measurement of both linear and angular kinematics. From a drop height of 2.0 m onto a flat steel anvil, each football helmet was impacted 5 times in the occipital area. RESULTS Skull fracture risk was determined for each of the current varsity football helmets by calculating the percentage reduction in linear acceleration relative to a 140-g skull fracture threshold. Risk of subdural hematoma was determined by calculating the percentage reduction in angular acceleration relative to the bridging vein failure threshold, computed as a function of impact duration. Ranking the helmets according to their performance under these criteria, the authors determined that the Schutt Vengeance performed the best overall. CONCLUSIONS The study findings demonstrated that not all football helmets provide equal or adequate protection against either focal head injuries or traumatic brain injuries. In fact, some of the most popular helmets on the field ranked among the worst. While protection is improving, none of the current or retired varsity football helmets can provide absolute protection against brain injuries, including concussions and subdural hematomas. To maximize protection against head and brain injuries for football players of all ages, the authors propose thresholds for all sports helmets based on a peak linear acceleration no greater than 90 g and a peak angular acceleration not exceeding 1700 rad/sec2.
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Kis, M., F. Saunders, M. W. ten Hove, and J. R. Leslie. "Rotational Acceleration Measurements - Evaluating Helmet Protection." Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 31, no. 4 (November 2004): 499–503. http://dx.doi.org/10.1017/s031716710000370x.
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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.
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Robinette, Kathleen M. "Fit Testing as a Helmet Development Tool." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 37, no. 1 (October 1993): 69–73. http://dx.doi.org/10.1177/154193129303700118.
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Fit testing is needed during the development process to reduce cost and optimize the performance quality. This paper describes methods for fit testing, as part of the helmet development process, which utilize new surface scanning and innovative fit assessment technologies. Results from some recent fit tests which employed these methods will be presented. While the methods described will be those applicable to helmets, many aspects will be appropriate to other equipment and clothing items as well. The payoff for using such methods are more capable and less bulky items, a better fit for a wider range of personnel with fewer sizes, and reduced development and logistics costs.
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Reid, Jennifer, and Eric L. Wang. "A System for Quantifying the Cooling Effectiveness of Bicycle Helmets." Journal of Biomechanical Engineering 122, no. 4 (March 22, 2000): 457–60. http://dx.doi.org/10.1115/1.1287163.
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This article describes the design and development of a system that is capable of quantifying the thermal comfort of bicycle helmets. The motivation for the development of the system stems from the desire both to increase helmet use and to provide the designer with a quantitative method of evaluating the thermal comfort of a helmet. The system consists of a heated mannequin head form, a heated reference sphere, a small wind tunnel, and a data acquisition system. Both the head form and the reference sphere were instrumented with thermocouples. The system is capable of simulating riding speeds ranging from 4.5–15.5 m/s. A cooling effectiveness, C1, that is independent of both ambient conditions and wind velocity is defined as a measure of how well the helmet ventilates as compared to the reference sphere. The system was validated by testing six commercially available bicycle helmets manufactured between approximately 1992 and 1998. [S0148-0731(00)02304-9]
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Steenstrup, Sophie E., Kam-Ming Mok, Andrew S. McIntosh, Roald Bahr, and Tron Krosshaug. "Head impact velocities in FIS World Cup snowboarders and freestyle skiers: Do real-life impacts exceed helmet testing standards?" British Journal of Sports Medicine 52, no. 1 (July 8, 2017): 32–40. http://dx.doi.org/10.1136/bjsports-2016-097086.
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IntroductionPrior to the 2013–2014 season, the International Ski Federation (FIS) increased the helmet testing speed from a minimum requirement of 5.4 to 6.8 m/s for alpine downhill, super-G and giant slalom and for freestyle ski cross, but not for the other freestyle disciplines or snowboarding. Whether this increased testing speed reflects impact velocities in real head injury situations on snow is unclear. We therefore investigated the injury mechanisms and gross head impact biomechanics in four real head injury situations among World Cup (WC) snowboard and freestyle athletes and compared these with helmet homologation laboratory test requirements. The helmets in the four cases complied with at least European Standards (EN) 1077 (Class B) or American Society for Testing and Materials (ASTM) F2040.MethodsWe analysed four head injury videos from the FIS Injury Surveillance System throughout eight WC seasons (2006–2014) in detail. We used motion analysis software to digitize the helmet’s trajectory and estimated the head’s kinematics in two dimensions, including directly preimpact and postimpact.ResultsAll four impacts were to the occiput. In the four cases, the normal-to-slope preimpact velocity ranged from 7.0(±SD 0.2) m/s to 10.5±0.5 m/s and the normal-to-slope velocity change ranged from 8.4±0.6 m/s to 11.7±0.7 m/s. The sagittal plane helmet angular velocity estimates indicated a large change in angular velocity (25.0±2.9 rad/s to 49.1±0.3 rad/s).ConclusionThe estimated normal-to-slope preimpact velocity was higher than the current strictest helmet testing rule of 6.8 m/s in all four cases.
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Mills, N. J., and A. Gilchrist. "Oblique impact testing of bicycle helmets." International Journal of Impact Engineering 35, no. 9 (September 2008): 1075–86. http://dx.doi.org/10.1016/j.ijimpeng.2007.05.005.
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Al Kautsar, Rachmad Jibril, Fitri Utaminingrum, and Agung Setia Budi. "Helmet Monitoring System using Hough Circle and HOG based on KNN." Lontar Komputer : Jurnal Ilmiah Teknologi Informasi 12, no. 1 (March 29, 2021): 13. http://dx.doi.org/10.24843/lkjiti.2021.v12.i01.p02.
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Indonesian citizens who use motorized vehicles are increasing every year. Every motorcyclist in Indonesia must wear a helmet when riding a motorcycle. Even though there are rules that require motorbike riders to wear helmets, there are still many motorists who disobey the rules. To overcome this, police officers have carried out various operations (such as traffic operation, warning, etc.). This is not effective because of the number of police officers available, and the probability of police officers make a mistake when detecting violations that might be caused due to fatigue. This study asks the system to detect motorcyclists who do not wear helmets through a surveillance camera. Referring to this reason, the Circular Hough Transform (CHT), Histogram of Oriented Gradient (HOG), and K-Nearest Neighbor (KNN) are used. Testing was done by using images taken from surveillance cameras divided into 200 training data and 40 testing data obtained an accuracy rate of 82.5%.
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Shelly, Zachary, Ethan Stewart, Tate Fonville, Reuben F. Burch V, Harish Chander, Lesley Strawderman, David May, JohnEric Smith, Daniel Carruth, and Cory Bichey. "Helmet Prototype Response Time Assessment using NCAA Division 1 Collegiate Football Athletes." International Journal of Kinesiology and Sports Science 7, no. 4 (October 31, 2019): 53. http://dx.doi.org/10.7575/aiac.ijkss.v.7n.4p.53.
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Background: With advances in concussion research, an increasing amount of resources are being allocated to advancing football helmet technology. Objective: This study assesses the claim that a new modified helmet prototype provides greater field of view for the user as compared to a commonly worn helmet by players. Method: The helmets—Riddell SpeedFlex and the modified helmet—were compared based on user response time while performing a response test task using the FITLIGHT Trainer system, actual helmet field of view blockage, users’ subjective perception of field of view, and balance tests. Eighteen National Collegiate Athletic Association (NCAA) Division 1 American football student-athletes completed the response test task and questionnaire. Results: The results demonstrate evidence that the SpeedFlex helmet provided by the equipment staff significantly increases wearers’ response times, F(2,20) = 5.646, p < 0.05. Also, while the quantification of the field of view perception was similar across helmet types, the student-athlete participants perceived the modified helmet to have significantly more field of view while performing the response test task, 1.56 v. 2.56; p < 0.05 for frontal vision and 2.83 v. 5.39; p < 0.05 for peripheral vision. Conclusion: In addition to the findings, this study also lays out a response time test protocol using the FITLIGHT Trainer system that can be used for assessment of response time testing of football and other helmets in future studies.
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Novak, James, David Burton, and Timothy Crouch. "Aerodynamic test results of bicycle helmets in different configurations: Towards a responsive design." Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 233, no. 2 (January 12, 2019): 268–76. http://dx.doi.org/10.1177/1754337118822613.
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Within the sport of cycling, aerodynamic efficiency is a fundamental criterion for equipment such as bicycle frames, wheels, clothing and helmets. Emerging technologies continually challenge the rules governing the sport as designers, engineers, sports scientists and athletes attempt to gain the edge on their competition. This study compares three-dimensional (3D) printed bicycle helmet prototypes with three commercially available helmets via aerodynamic testing in a wind tunnel. One 3D printed helmet featured a mechanical mechanism allowing two states of ventilation closure to be examined for aerodynamic efficiency, while the other featured electronically adjustable ventilation openings tested at five different states of ventilation closure. Data were collected using an anthropometrically accurate mannequin sitting atop a bicycle in a road-cycling position. The results found that the mechanically controlled prototype offered a 4.1% increase in overall drag experienced by the mannequin with ventilation in the open position compared to the closed position. The electronic prototype showed an increase in drag as ventilation openings increased through the five states, with an overall difference in drag of 3.7% between closed and the maximum opening. These experimental findings indicate that the responsive helmet prototypes can significantly affect the drag force on a cyclist between their closed and open positions and, when understood as being adaptable using sensors and automated controls, may provide new opportunities to modify athlete performance throughout varying stages of training and competition.
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Zerpa, Carlos, Stephen Carlson, Eryk Przysucha, Meilan Liu, and Paolo Sanzo. "Evaluating the Performance of a Hockey Helmet in Mitigating Concussion Risk Using Measures of Acceleration and Energy During Simulated Free Fall." International Journal of Extreme Automation and Connectivity in Healthcare 3, no. 2 (July 2021): 33–50. http://dx.doi.org/10.4018/ijeach.2021070104.
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Hockey helmets represent the best form of head protection available to reduce the occurrence of skull fracture and concussion. Currently, helmet testing protocols focus on the reduction of peak linear acceleration measures. Gaps exist in analyzing how certain impact factors such as angle, neck stiffness, and location influence the energy loaded to the helmet and the risk of injury during head collisions. This study examined the effect of helmet impact angle, neck stiffness-torque levels, and helmet impact locations on energy reduction and risk of head injury grounded on acceleration measures using simulated free fall head collisions. The researchers conducted 540 impacts to collect the data. The results revealed statistical interaction effects between the angle of impact and location on measures of energy and risk of head injury. This study builds on existing literature by introducing an energy measurement technique to assess helmet performance. The outcome also provides an avenue for helmet manufacturers to evaluate the performance of the helmet in reducing concussion risk.
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Zlámal, Petr, Tomáš Fíla, and Vlastimil Králík. "Testing of Energy Absorption Capability of Sandwich Structures Based on Metal Foams for Design of Protective Helmets." Applied Mechanics and Materials 821 (January 2016): 420–27. http://dx.doi.org/10.4028/www.scientific.net/amm.821.420.
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Purpose of this study is investigation of energy absorption capability of the sandwich structures composed of combination of polystyrene and metal foam element and their suitability as new structure for design of protective helmets. Two types of the metal foams were experimentally tested and evaluated: Alporas (Shinko Wire Ltd., Japan) and Aluhab (Aluinvent Plc., Hungary). Samples of the sandwich structure are composed of two layers: bottom expanded polystyrene (EPS 200S) layer and upper metal foam layer which are glued together. Prepared samples are tested using a drop tower experiment to measure sample response (acceleration, reaction force) at different strain rates and energies. From acceleration/time history the Head Injury Criterion (HIC) is calculated as significant parameters in terms of protective helmets. Moreover, measured and derived characteristics are compared with pure EPS samples to obtain comparison of deformation behaviour between conventional structure for protective helmets and designed sandwich structures.
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Johnson, Gustav Ingmar. "Investigations on impact testing of head injury protection helmets." International Journal of Crashworthiness 5, no. 4 (January 2000): 491–502. http://dx.doi.org/10.1533/cras.2000.0156.
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Bloodworth-Race, S., R. Critchley, R. Hazael, A. Peare, and T. Temple. "Testing the blast response of foam inserts for helmets." Heliyon 7, no. 5 (May 2021): e06990. http://dx.doi.org/10.1016/j.heliyon.2021.e06990.
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de Grau, Santiago, Andrew Post, T. Blaine Hoshizaki, and Michael D. Gilchrist. "Effects of surface compliance on the dynamic response and strains sustained by a player’s helmeted head during ice hockey impacts." Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 234, no. 1 (September 11, 2019): 98–106. http://dx.doi.org/10.1177/1754337119871866.
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In hockey, players experience different compliances during impacts to the head, from stiff ice to compliant collisions against other players. The objective of this study was to examine the effect of striking compliance in ice hockey impacts and its influence on dynamic response and brain tissue strain. Three striking caps of low, medium, and high compliances were used to impact a helmeted 50th-percentile Hybrid III headform. The headform was impacted at five locations at three velocities, representative of collision scenarios in hockey. The dependent variables, peak resultant linear and rotational acceleration as well as maximum principal strain were analyzed using a multivariate analysis of variance to determine significant differences between the compliances. The results indicated a significant effect of compliance on the responses of the headform. As expected, low-impact compliance resulted in higher linear and rotational accelerations when compared to the medium and high compliance conditions. However, while the linear and rotational acceleration responses of the medium and high compliance conditions would indicate a low chance of brain injury, the maximum principal strain magnitudes indicated a high likelihood of concussion. Medium- and high-impact compliances are a factor that has not been considered when designing and testing helmet technology in sport, with current methods reflective of low compliance surfaces, that is, those with high stiffness and rigidity. The results of this study demonstrate that an impact compliance is an important factor in producing brain injury and should be considered when certifying helmets through standard testing to mitigate the risk of brain injury.
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Cummiskey, Brian, David Schiffmiller, Thomas M. Talavage, Larry Leverenz, Janette J. Meyer, Douglas Adams, and Eric A. Nauman. "Reliability and accuracy of helmet-mounted and head-mounted devices used to measure head accelerations." Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 231, no. 2 (August 3, 2016): 144–53. http://dx.doi.org/10.1177/1754337116658395.
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The attention given to brain injury has grown in recent years as its effects have become better understood. A desire to investigate the causal agents of head trauma in athletes has led to the development and use of several devices that track head impacts. In order to determine which devices best measure these impacts, a Hybrid III headform was used to quantify the accuracy for translational and angular accelerations. Testing was performed by mounting each device into the helmet as instructed by its manufacturer, fitting the helmet on the headform, and impacting the helmet using an impulse hammer. The root mean square error for the peak translational acceleration varied with location. The worst root mean square error for a head-mounted device was 74.7% while the worst for a helmet-mounted device was 298%. Head-mounted devices consistently outperformed those mounted in helmets, suggesting that future sensor designs should avoid attachment to the helmet. Deployment to a high school football team affirmed differences between two of the device models, but strongly indicated that head-mounted systems require further development to account for variation between individuals, the relative motion of the skin, and helmet–sensor interactions. Future work needs to account for these issues, refine the algorithms used to estimate the translational and angular accelerations, and examine technologies that better locate the source of the impact.
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Broshek, Donna K., Tanya Kaushik, Jason R. Freeman, David Erlanger, Frank Webbe, and Jeffrey T. Barth. "Sex differences in outcome following sports-related concussion." Journal of Neurosurgery 102, no. 5 (May 2005): 856–63. http://dx.doi.org/10.3171/jns.2005.102.5.0856.
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Object. Females comprise an increasing percentage of the athlete population across all age groups, and analysis of recent literature reveals that they sustain more concussions in collegiate sports. Results of human and animal studies indicate that females may have poorer outcomes after traumatic brain injury; however, no return-to-play guideline takes sex or other individual differences into account. In the present study the authors evaluated the influence of patient sex on objective neurocognitive performance and subjective reporting of symptoms following sports-related concussion. Methods. According to preseason baseline neurocognitive computerized testing in 2340 male and female high school and collegiate athletes, individuals who sustained sports-related concussions (155 persons) were reevaluated using an alternate form of the cognitive test. Sex differences in the magnitude of cognitive change from baseline levels and the subjective experience of symptoms were analyzed. To account for the possible protective effects of helmets, comparisons were performed among females, males with helmets, and males without helmets; none of the female athletes wore helmets. Female athletes had significantly greater declines in simple and complex reaction times relative to preseason baseline levels, and they reported more postconcussion symptoms compared with males. As a group, females were cognitively impaired approximately 1.7 times more frequently than males following concussions. Furthermore, females experienced more objective and subjective adverse effects from concussion even after adjusting for the use of helmets by some groups of male athletes (for example, in football). Conclusions. Return-to-play decisions and concussion management must be objective and made on an individual basis, including consideration of factors such as patient sex rather than relying on a one-size-fits-all guideline.
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Jachowicz, Marcin. "Helmets for sport and recreation – construction and standards’ requirements." Occupational Safety – Science and Practice 563, no. 8 (August 14, 2018): 8–11. http://dx.doi.org/10.5604/01.3001.0012.2223.
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While practicing sports and participating in recreational activities, humans are exposed to a number of hazards, among which head injuries are one of the most dangerous. We are unable to completely eliminate them, e.g., when cycling, skateboarding, skiing or snowboarding. For this reason, all sorts of protective headgear selected according to the prevailing threats are applicable to protect the head. The design of such equipment is continuously changing and evolving. New materials and technical solutions that aim to increase the user’s safety and comfort are introduced. To achieve that goal, it becomes necessary to reduce the weight and increase the functionality of protective helmets. Such goals can be met only by creating more specialized structures designed not only for the intended physical activity but also for the specific conditions in which it is practiced. This paper contains material that presents the basic protective helmets and the materials used for their construction, as well as a review of the design of helmets for sports and recreational activities protecting the head against impact against stationary objects. General information concerning the regulatory requirements and the methods of testing of this type of equipment has also been presented.
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Scott, M. D., D. B. Buller, P. A. Andersen, B. J. Walkosz, J. H. Voeks, M. B. Dignan, and G. R. Cutter. "Testing the risk compensation hypothesis for safety helmets in alpine skiing and snowboarding." Injury Prevention 13, no. 3 (June 1, 2007): 173–77. http://dx.doi.org/10.1136/ip.2006.014142.
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Tripathy, NK, N. Divya, and V. Raghunandan. "Windblast testing of an aircrew helmet: An approach to neck load analysis." Indian Journal of Aerospace Medicine 63 (October 3, 2020): 77–82. http://dx.doi.org/10.25259/ijasm_8_2019.
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Introduction: Modern generation fighter aircraft has expanded the escape envelope for a fighter aircrew. With the ejection occurring at very high airspeeds, windblast is a cause of major injuries and fatalities. Flying helmet, before its induction into operational usage, must be tested in simulated windblast conditions to ensure that they provide adequate safety. Material and Methods: Windblast tests were conducted on a newly designed/procured helmet in a standard windblast test facility as per Mil Std MIL-V-29591/1. A large instrumented Hybrid III male dummy was used for the tests. The test conditions were: Wind speed 600 ± 60 KEAS, rise time of 125 ± 20 ms, time at peak wind velocity of 300 ± 50 ms, and total exposure time of ≥3 s. Structural integrity, retention with the headform, and recorded neck loads were assessed for interpretation of test results. Results: Helmets could withstand the windblast conditions without any significant structural failures and were retained with the headform during the entire duration of test conditions. However, analysis of the neck loads resulted in a significant dilemma in aeromedical decision-making, there being no laid down criteria in the Mil Specification. The neck tension forces were more than the acceptable limits and found to have the potential for significant neck injuries as per the Injury Assessment Reference Values specified in AGARD-AR-330 specifically in the tests where blast was head on and outer visor in up configuration; however, these values were within the acceptable limits as per the other proposed criteria. Similarly, analysis of the neck tension extension combined effects revealed conflicting outcomes for Nij performance limits specified in various standards. This paper discusses the critical analysis of neck loads vis-à-vis the neck injury criteria to understand the neck loads generated during windblast conditions and its implication on aircrew safety. Conclusion: Neck loads assessment is critical in predicting aircrew safety during windblast testing. In the absence of a clearly defined criteria in the Mil Specification, critical ananlysis of neck loads vis-à-vis recommended standards in scientific literature be done to make meaningful conclusion.
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WITTE, KIM, DANIEL STOKOLS, PHILIP ITUARTE, and MARGARET SCHNEIDER. "Testing the Health Belief Model in a Field Study to Promote Bicycle Safety Helmets." Communication Research 20, no. 4 (August 1993): 564–86. http://dx.doi.org/10.1177/009365093020004004.
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Fejdyś, Marzena, Karolina Olszewska, Sylwia Kaczmarczyk, and Grzegorz Owczarek. "Coatings manufactured using magnetron sputtering technology to protect against infrared radiation for use in firefighter helmets." Polish Journal of Chemical Technology 18, no. 3 (September 1, 2016): 50–58. http://dx.doi.org/10.1515/pjct-2016-0048.
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Abstract The aim of this study was to test the usefulness of magnetron sputtering technology to produce coatings on selected elements of a firefighter’s helmet to protect against infrared radiation (PN-EN 171 standard). The scope of research includes testing the deposition produced via magnetron sputtering of metallic and ceramic coatings on plastics, which are used to manufacture the components comprising the personal protection equipment used by firefighters. The UV-VIS, NIR used to research the permeation coefficients and reflections for light and infrared light and the emission spectrometry with ICP-AES used for the quantitative analysis of elements in metallic and ceramic coatings. Microstructural and micro-analytical testing of the coatings were performed using scanning electron microscopy (SEM). Measurements of the chemical compositions were conducted using energy-dispersive X-ray spectroscopy (EDS). The hardnesss of the coatings were tested using a indentation method, and the coating thicknesses were tested using a ellipsometry method.
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Pratellesi, A., S. Turrin, T. Haag, A. Scippa, and N. Baldanzini. "On the effect of testing uncertainties in the homologation tests of motorcycle helmets according to ECE 22.05." International Journal of Crashworthiness 16, no. 5 (October 2011): 523–36. http://dx.doi.org/10.1080/13588265.2011.611397.
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Swaroop, Swaroop, and Deepika Prabhakar. "Hardhat Detection Using IR and Depth Frames." Journal of University of Shanghai for Science and Technology 23, no. 06 (June 18, 2021): 1141–47. http://dx.doi.org/10.51201/jusst/21/05310.
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The construction industry is one of the largest sectors and 20% of the total deaths happen here. Safety hardhat helmets are one of the precautionary methods recommended and followed in a construction site. Detecting and classifying people wearing and not wearing helmets is an important task. Safety and Security is one of the most researched fields in recent years and acquiring 3D geometric information from any real environment is an important task for such applications. Well-known methods like stereo vision camera systems suffer from high time consumption or from the inability to match corresponding points inhomogeneous regions. Time of Flight (ToF)technology, being a recent development, fulfills features desired for real-time distance acquisition along with the compact size and higher frame rate. A safety application based on the ToF technology ad IR imaging is proposed in the paper. The ToF sensor provides depth information for each pixel as opposed to RGB values in case stereo camera-based systems. The depth sense cameras provide IR images along with the depth information. A YOLO framework is used to classify images. YOLO being faster than RCNN and the faster RCNN is much suitable for real-time classification. The model was trained on 50,000 images. Weights obtained during the 6000th epoch were chosen. A Mean Average Precision of 56% was obtained while testing.
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Diakogeorgiou, Eleni, and Theresa L. Miyashita. "Effect of Head Impact Exposures on Changes in Cognitive Testing." Orthopaedic Journal of Sports Medicine 6, no. 3 (March 1, 2018): 232596711876103. http://dx.doi.org/10.1177/2325967118761031.
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Background: Gaining a better understanding of head impact exposures may lead to better comprehension of the possible effects of repeated impact exposures not associated with clinical concussion. Purpose: To assess the correlation between head impacts and any differences associated with cognitive testing measurements pre- and postseason. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 34 National Collegiate Athletic Association Division I men’s lacrosse players wore lacrosse helmets instrumented with an accelerometer during the 2014 competitive season and were tested pre- and postseason with the Sport Concussion Assessment Tool (SCAT 3) and Concussion Vital Signs (CVS) computer-based neurocognitive tests. The number of head impacts >20 g and results from the 2 cognitive tests were analyzed for differences and correlation. Results: There was no significant difference between pre- and postseason SCAT 3 scores, although a significant correlation between pre- and postseason cognitive scores on the SCAT 3 and total number of impacts sustained was noted ( r = –0.362, P = .035). Statistically significant improvements on half of the CVS testing components included visual reaction time ( P = .037, d = 0.37), reaction time ( P = .001, d = 0.65), and simple reaction time ( P = .043, d = 0.37), but no correlation with head impacts was noted. Conclusion: This study did not find declines in SCAT 3 or CVS scores over the course of a season among athletes who sustained multiple head impacts but no clinical concussion. Thus, it could not be determined whether there was no cognitive decline among these athletes or whether there may have been subtle declines that could not be measured by the SCAT 3 or CVS.
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Marsalek, Pavel, Martin Sotola, David Rybansky, Vojtech Repa, Radim Halama, Martin Fusek, and Jiri Prokop. "Modeling and Testing of Flexible Structures with Selected Planar Patterns Used in Biomedical Applications." Materials 14, no. 1 (December 30, 2020): 140. http://dx.doi.org/10.3390/ma14010140.
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Flexible structures (FS) are thin shells with a pattern of holes. The stiffness of the structure in the normal direction is reduced by the shape of gaps rather than by the choice of the material based on mechanical properties such as Young’s modulus. This paper presents virtual prototyping of 3D printed flexible structures with selected planar patterns using laboratory testing and computer modeling. The objective of this work is to develop a non-linear computational model evaluating the structure’s stiffness and its experimental verification; in addition, we aimed to identify the best of the proposed patterns with respect to its stiffness: load-bearing capacity ratio. Following validation, the validated computational model is used for a parametric study of selected patterns. Nylon—Polyamide 12—was chosen for the purposes of this study as an appropriate flexible material suitable for 3D printing. At the end of the work, a computational model of the selected structure with modeling of load-bearing capacity is presented. The obtained results can be used in the design of external biomedical applications such as orthoses, prostheses, cranial remoulding helmets padding, or a new type of adaptive cushions. This paper is an extension of the conference paper: “Modeling and Testing of 3D Printed Flexible Structures with Three-pointed Star Pattern Used in Biomedical Applications” by authors Repa et al.
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Mahadi, Mahadi. "Respon Helmet Sepeda Type BMX Material Polymeric Foam Diperkuat Serbuk Tandan Kosong Kelapa Sawit Terhadap Beban Impak Metode Jatuh Bebas." Talenta Conference Series: Energy and Engineering (EE) 1, no. 1 (October 16, 2018): 109–16. http://dx.doi.org/10.32734/ee.v1i1.119.
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Pengujian impak standar pada helmet sepeda diperlukan untuk mengetahui respon tegangan pada helmet akibat efek rambatan gelombang regangan dengan laju rambatan gelombang yang tinggi. Tujuan dari penelitian ini adalah untuk mengetahui berapa besar energi yang dapat diserap oleh helmet sepeda bila diberi beban impak. Penelitian dilakukan terhadap helmet sepeda type BMX dengan formasi saluran udara (wind channel) tertentu yang terbuat dari material polymeric foam diperkuat serbuk tandan kosong kelapa sawit (TKKS) mesh40. Struktur geometri helmet uji terdiri dari lapisan luar (shell) terbuat dari material matrix resin unsaturated Polyester BQTN-157EX dan penguat serat glass chopped strand mat 300. Lapisan dalam (liner) adalah material polymeric foam menggunakan matrix resin unsaturated Polyester BQTN-157EX, penguat serbuk TKKS mesh40, Blowing AgentPolyurethane dan katalis Methyl Ethyl Keton Peroksida (MEKPO). Nilai dari sifat mekanik polymeric foam adalah tegangan tarik (σt) 1,17 MPa, tegangan tekan (σc) 0,51 MPa, tegangan bending (σb) 3,94 MPa, modulus elastisitas (E) 37,97 Mpa dan density (ρ) 193 (kg/m3). Metode impak yang dilakukan adalah jatuh bebas standar Consumer Product Safety Commision (CPSC). Helmet sepeda yang diuji adalah hasil dari desain standar Bicycle Helmet Safety Institute (BHSI) yang mempunyai dimensi panjang 264 mm, lebar 184 mm, dan tinggi 154 mm dengan lingkar kepala 580 mm. Massa test rig pada alat uji yang digunakan sebesar 5 kg dan massa helmet sepeda hasil cetakan bervariasi 328 s/d 451gr. Pengujian impak jatuh bebas dilakukan pada 18 sampel helmet ketebalan 10 mm dan 20 mm pada ketinggian 1,5 m dengan menggunakan flat anvil. Hasil uji impak pada parameter Gaya impak terbesar (Fi ), Energi Impak terbesar (Ei), Impuls (I), Tegangan Impak terbesar (σi) adalah 241,55 N, 283,77 J, 6,28 Ns, 2,02 MPa untuk tebal 10 mm dan 226,80 N, 360,23 J, 6,80 Ns, 1,90 MPa untuk tebal 20 mm.
Standard impact testing on bicycle helmets is needed to determine the response on the helmet voltage due to the effect of strain wave propagation with a high a rate of wave propagation. The purpose of this reseach is to find out how much energy can be absorbed by the bicycle helmet if it is given an impact load. The reseach was conducted on BMX type bicycle helmet with a certain wind channels formation made of polymeric foam material strengthened by the powder of oil palm empty bunches (TKKS) mesh40. The geometry structure of the tested helmet consists of a shell made by the material of unsaturated Polyester BQTN-157EX resin and the fiber strengthener of glass chopped strand mat 300. The inner layer (liner) is a polymeric foam material using unsaturated Polyester BQTN-157EX resin matrix, TKKS powder strengthener Mesh40, Blowing Agent Polyurethane and catalyst Methyl Ethyl Ketone Peroxide (MEKPO). The characterizatons of the polymeric foam mechanical are tensile stress (σt) 1.17 MPa, compression stress (σc) 0.51 MPa, bending stress (σb) 3.94 MPa, elastic modulus (E) 37.97 Mpa and density (ρ ) 193 (kg / m3). The impact method was using the standard free fall of the Consumer Product Safety Commission (CPSC). The bicycle helmet tested is the result of the standard Bicycle Helmet Safety Institute (BHSI) design that has dimensions of 264 mm in length, 184 mm in width, and 154 mm in height with a head circumference of 580 mm. The mass of the test rig on the test equipment used was 5 kg and the helmet mass of the printed bicycle varied from 328 to 451gr. The free fall impact test was carried out on 18 helmet samples thickness of 10 mm and 20 mm at an altitude of 1.5 m using anvil flat. The impact test results in the parameters of the largest impact force (Fi), the largest impact energy (Ei), Impuls (I), the largest impact voltage (σi) are 241.55 N, 283.77 J, 6.28 Ns, 2.02 MPa for 10 mm and 226.80 N thickness, 360.23 J, 6.80 Ns, 1.90 MPa for 20 mm thickness.
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Papadopoulou, Joanna, Vassilis Papakostopoulos, and Vassilis C. Moulianitis. "RE-DESIGN OF A MOTORCYCLE HELMET FOR USE IN URBAN TRAFFIC: CONCEPTUAL DESIGN AND TESTING." Proceedings of the Design Society 1 (July 27, 2021): 2531–40. http://dx.doi.org/10.1017/pds.2021.514.
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AbstractThis paper presents the re-design approach of an urban motorcycle helmet to prevent users bypassing the strap fastening system. Related studies show that although a full-face helmet provides the maximum protection to a rider, in practice, full-face helmeted riders in urban traffic tend to improperly fasten it. On that notion, the design goal was to conceive a helmet that combines the advantages of different helmet types while responding to urban driving needs. During design ideation possible solutions were examined focusing on different ways of accessing and fixating the helmet on a rider’s head, without using a strap fastening system. Preliminary concept development produced three design concepts, that were evaluated using two sets of prototypes: (a) the 3D printing method under a 1:2 scale was used to detect any design faults, while the 3D modeled concepts were evaluated in four different crash impacts regarding total deformation and von-Mises stress, and (b) 1:1 models of the three concepts were used by experienced riders to assess possible usability issues during helmet placement/removal. Results of the two-phase evaluation of the three concepts and design issues for further development of them are discussed.
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Chanda, Arnab, and Rebecca Graeter. "Human Skin-Like Composite Materials for Blast Induced Injury Mitigation." Journal of Composites Science 2, no. 3 (August 1, 2018): 44. http://dx.doi.org/10.3390/jcs2030044.
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Armors and military grade personal protection equipment (PPE) materials to date are bulky and are not designed to effectively mitigate blast impacts. In the current work, a human skin-like castable simulant material was developed and its blast mitigation characteristics (in terms of induced stress reduction at the bone and muscles) were characterized in the presence of composite reinforcements. The reinforcement employed was Kevlar 129 (commonly used in advanced combat helmets), which was embedded within the novel skin simulant material as the matrix and used to cover a representative extremity based human skin, muscle and bone section finite element (FE) model. The composite variations tested were continuous and short-fiber types, lay-ups (0/0, 90/0, and 45/45 orientations) and different fiber volume fractions. From the analyses, the 0/0 continuous fiber lay-up with a fiber volume fraction close to 0.1 (or 10%) was found to reduce the blast-induced dynamic stresses at the bone and muscle sections by 78% and 70% respectively. These findings indicate that this novel skin simulant material with Kevlar 129 reinforcement, with further experimental testing, may present future opportunities in blast resistant armor padding designing.
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Shoji, Takuro, and Gordon Lovegrove. "Integrating Communication with Conspicuity to Enhance Vulnerable Road User Safety: ArroWhere Case Study." Sustainability 11, no. 10 (May 14, 2019): 2761. http://dx.doi.org/10.3390/su11102761.
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This paper presents findings from a research study into the role that communication plays in the safety of vulnerable road users (VRUs), including a literature review, a hypothesis, and a case study testing our hypothesis. Many governments and road authorities lack capital or have not made it a priority to implement full VRU safety measures, with many gaps in VRU infrastructure and networks. These gaps leave VRUs to take safety into their own hands, including use of conspicuity aids such as high-visibility wear, helmets, bells, and lights with differing levels of effectiveness. The knowledge gap regarding the conventional wisdom, “be safe, be seen,” is the absence of communication and comprehension between road users (VRUs and vehicles). We hypothesize that communication aids are equally, if not more important than visibility aids for VRU safety. A case study was conducted to measure the effectiveness of several Hi-Viz safety vest designs including online surveys and separate in-field experiments using Instrumented Probe Bicycles. The results suggest that Hi-Viz safety vests using arrow designs (ArroWhere’s proprietary products and designs) similar to those found in the Manual on Uniform Traffic Control Devices (MUTCD) can increase VRU safety until road authorities can fully fund and complete proper and sustainable VRU networks.
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Laoprasert, Nunthaporn, Mark C. Swanson, Richard T. Jones, Darrell R. Schroeder, and John W. Yunginger. "Inhalation challenge testing of latex-sensitive health care workers and the effectiveness of laminar flow HEPA–filtered helmets in reducing rhinoconjunctival and asthmatic reactions☆☆☆★★★." Journal of Allergy and Clinical Immunology 102, no. 6 (December 1998): 998–1004. http://dx.doi.org/10.1016/s0091-6749(98)70338-0.
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Eckner, James T., R. Scott Conley, Hugh J. L. Garton, Nikki Weiss, Lauro Ojeda, Amanda O. Esquivel, Ryan Kassel, et al. "Comparing head impact kinematics simultaneously measured using 6 different sensors in a human cadaver model." Neurology 91, no. 23 Supplement 1 (December 4, 2018): S2.3—S3. http://dx.doi.org/10.1212/01.wnl.0000550624.74128.72.
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ObjectiveTo compare head kinematics measurements obtained from 6 different head impact sensors utilizing different methods of sensor-to-head fixation.DesignFree-drop impacts (total n = 54) were performed at 3.5 and 5.5 m/s onto to the front, back, side, and top of 2 elderly human cadaveric head-neck specimens: a helmeted (Riddell Revolution Speed) male specimen was dropped onto a NOCSAE testing pad; an un-helmeted female specimen was dropped onto a framed sample of field turf. The specimens were instrumented with an intracranial reference sensor surgically mounted at the approximate head center-of-mass by a rigidly-fixed custom standoff pad, an intra-oral test sensor rigidly fixed to the upper teeth/hard palate by a custom orthodontic appliance, and 4 commercially available head impact sensing systems: X-Patch, Vector mouth guard, HITS (helmeted condition only), and G-Force Tracker (affixed to helmet interior or head band depending on helmet status). Peak linear and rotational head accelerations (PLA and PRA) were compared between each sensor and the intracranial reference sensor using intraclass correlation coefficients (ICC [2, 1]).ResultsAgreement with reference PLA and PRA values differed between sensors, with the greatest agreement observed for the rigidly affixed intraoral sensor (ICC = 0.921, PLA; ICC = 0.810, PRA). Agreement for PLA and PRA, respectively, was: for X-Patch, ICC = 0.638, ICC = 0.155; for Vector mouth guard, ICC = 0.775, ICC = 0.480; for HITS, ICC = 0.662 (PLA only); for G-Force Tracker, ICC = 0.364 (PLA only).DiscussionHead kinematics measurements during free-drop testing differed among sensors using different approaches of fixation to the head. There was greater agreement with intracranial reference PLA and PRA values for a rigidly affixed intraoral sensor utilizing an orthodontic appliance than for commercially available sensors incorporated into athletic equipment or otherwise non-rigidly affixed to the head. Measurement error attributable to non-rigid sensor-head coupling could potentially be reduced by incorporating an impact sensor into an orthodontic appliance in future research.
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Carlson, Stephen, Carlos Zerpa, Eryk Przysucha, and Paolo Sanzo. "Mitigation of Linear Accelerations and Shear Forces During Drop Head Simulated Falls." International Journal of Extreme Automation and Connectivity in Healthcare 1, no. 2 (July 2019): 38–55. http://dx.doi.org/10.4018/ijeach.2019070103.
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The danger and risk associated with ice hockey has led to the development of new helmet technologies and testing protocols to minimize the risk of traumatic brain injuries or concussions. Researchers believe that understanding helmet performance across different impact locations and angles during head collisions helps inform helmet manufacturers in the development of helmet testing protocols for brain injury prevention. Based on these beliefs and concerns, this study examined the dynamic interaction of neck compliance, helmet location, and angle of impact in mitigating linear acceleration and shear forces. The results support the hypothesis that an increasing angle of impact decreases peak linear acceleration and increases shear force. Decreasing neck compliance, however, decreases peak linear acceleration and shear force for some helmet impact locations but not all of them. These results add to the literature by implementing a new helmet testing protocol to provide information beyond traditional measures of peak linear acceleration used in current helmet testing standards.
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Simanjuntak, Rahmat Kartolo. "Analisa Kekuatan Impak Helmet Sepeda Motor Metode Impak Jatuh Bebas." Jurnal Inotera 2, no. 1 (August 8, 2017): 42. http://dx.doi.org/10.31572/inotera.vol2.iss1.2017.id19.
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The non-standard helmet testing is required for measure the helmet strength as effect of the load is given. In generally, traffic accident doesn�t involved by the velocity but also gravitational. Therefore, the research activity is done by researcher obtains the effect of free-fall impact loading on the non-standard helmet. The information which is obtained from this research will explain the effect of free-fall impact loading that is subjected on the non-standard helmet to user, industry, and also government. The objective of this research involves the testing apparatus construction of free-fall impact loading on the non-standard helmet, measuring the maximum impact loading, and the energy absorbing by helmet as effect of impact loading. The researcher collaborates with the Impact and Fracture Reaseach Center (IRFC) has bulit the testing apparatus which is equipped with good aquisition data system. The non-standar helmet is put on the adjustable testing rig. The impact time can be measured by eight inductive proximity sensors. The helmet will slide down and collides the anvil. The force will be measured with the load cell which is put down the anvil. There are four anvil forms which is adapted to the real condition, that is: flat plat, aligned plat, bullet, and a half-spherical anvil. The data will be transfered from the load cell into the DAQ system which has function to change the analog into digital signal. Finally, the data will be saved into PC as the force (N) and the impact time (ms). The free-fall impact testing equipment has shown the best performance on the force and impact time signal reading as long as the research activity. The maximum force on the flat anvil is 24.33 N; the aligned flat anvil is 37.88 N; the bullet anvil is 16.22 N; and a half-spherical anvil is 41.43 N at the elevation of 0.75 m. The minimum energy which causes the fracture on the helmet is 3.24 J at the elevation of 0.3 m.
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Aare, M., S. Kleiven, and P. Halldin. "Injury tolerances for oblique impact helmet testing." International Journal of Crashworthiness 9, no. 1 (January 2004): 15–23. http://dx.doi.org/10.1533/ijcr.2004.0268.
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Mihora, D., J. Hutchinson, K. Friedman, J. Valente, T. Flanagan, A. Sances, and S. Kumaresan. "Bicycle helmet retention system testing and evaluation." International Journal of Crashworthiness 12, no. 3 (September 25, 2007): 211–15. http://dx.doi.org/10.1080/13588260701440862.
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He, Jing Feng, and Ya Nan Wang. "Two Degree of Freedom Helmet Mounted Sight Testing System." Applied Mechanics and Materials 496-500 (January 2014): 1560–63. http://dx.doi.org/10.4028/www.scientific.net/amm.496-500.1560.
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In the light of the backwardness of test means, over-complication in operation and inaccessibly to the test of the system main performance parameters in the case of army equipping Helmet Mounted Sight (HMS), extensive researches are conducted on improvement and home manufacture of HMS in No.×× project, to solve the actual problem of maintenance in the army, give a full insight into the principle of HMS and effectively better the utilization and maintenance of military of military equipment and study on the HMS test system . KEY WORDS: Helmet Mounted Sight,test system,Step motor,Control system
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Sugianto, Sugianto. "DETEKSI ALAT PELINDUNG KEPALA (HELM) MENGGUNAKAN METODE HAAR CASCADE CLASSIFIER." Joutica 4, no. 1 (March 1, 2019): 189. http://dx.doi.org/10.30736/jti.v4i1.283.
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Use of protective gear helmet head is often considered unimportant and trivial by workers. Whereas the use of protective headgear helmet is very important and affect the safety and health of workers. Kedisiplina workers to use protective gear head is still low so that the risk of accidents that could endanger workers large enough. In this research aims to detect protective equipment head helmet on video. In this study, the method used is the Haar Cascade Classifier. The system consists of two main processes, namely the process of training data and the detection process. This method of training process has four main processes, haar-like feature, integral image, no-boost and cascade classifier. Haar-like feature is a collection of special features presented the head, face and helmet. Citra is how to quickly calculate integrals haar feature. While no-boost are statistically weighted feature values are obtained and filtered using a cascade classifier. The detection process in this study there are two processes, the first detection process whether human or not, if the result of human detected will continue the process of detection of whether to use a helmet or not. Detection system testing is done individually using helmet colors red, blue and yellow. It obtained accuracy rate of 92%, while the testing group obtained the degree of accuracy of 71%.
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Petersen, DR, RE Link, and G. Ingmar Johnson. "A Comparison of Results on Helmet Impact Testing." Journal of Testing and Evaluation 31, no. 1 (2003): 11141. http://dx.doi.org/10.1520/jte12357j.
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