Xavier Trosseille, Philippe Petit, Jérôme Uriot, Pascal Potier, Pascal Baudrit
Several studies, available in the literature, were conducted to establish the most relevant criterion for predicting the thoracic injury risk on the THOR dummy. The criteria, such as the maximum deflection or a combination of parameters including the difference between the chest right and left deflections, were all developed based on given samples of Post Mortem Human Subject (PMHS). However, they were not validated against independent data and they are not always consistent with the observations from field data analysis. For this reason, 8 additional PMHS and matching THOR tests were carried out to assess the ability of the criteria to predict risks. Accident investigations showed that a reduction of the belt loads reduces the risk of rib fractures. Two configurations with different levels of force limitation were therefore chosen. A configuration representing an average European vehicle was chosen as a reference. It consists of a 3-point belt with a 3.5 kN and then 2 kN digressive limiter, combined with a 54-liter airbag. For better reproducibility and durability, the tests were performed with a pre-inflated bag and a semi-rigid seat. In this first configuration, the THOR dummy had a maximum resulting deflection of 43 mm. To differentiate the criteria, the second configuration was chosen such that it resulted in about the same deflection on the THOR dummy, but with a 5 kN belt force limitation combined with a lower pressure airbag. To reach this target of 43 mm, the pulse severity was lowered. Some criteria were higher in this second configuration, which allows them to be distinguished from the maximum deflection criterion. Four tests on four PMHS were performed in each configuration. The injury assessments showed that the total number of fractures was almost the same in both configurations, but that the number of separated fractures was greater in the 5 kN configuration. 25% of the subjects sustained AIS >3 injuries related to the number of displaced fractures in the 3.5/2 kN load limitation configuration. The result increased to 75% in the 5kN configuration. In total, 8 PMHS and the matching THOR tests were performed and used to assess the ability of the thoracic criteria to predict rib fractures in 2 types of chest loading configurations. The test results did not allow to conclude on the relevance of the criteria measured on the THOR dummy for the total number of rib fractures identified at autopsy (NFR). However, clearly different assessments for separated rib fractures (NSFR), make it possible to differentiate the criteria. The maximum resultant deflection failed to properly predict separated rib fractures while other criteria that include the left-to-right rib deflection difference did.
{"title":"Assessment of Several THOR Thoracic Injury Criteria based on a New Post Mortem Human Subject Test Series and Recommendations.","authors":"Xavier Trosseille, Philippe Petit, Jérôme Uriot, Pascal Potier, Pascal Baudrit","doi":"10.4271/2019-22-0012","DOIUrl":"https://doi.org/10.4271/2019-22-0012","url":null,"abstract":"<p><p>Several studies, available in the literature, were conducted to establish the most relevant criterion for predicting the thoracic injury risk on the THOR dummy. The criteria, such as the maximum deflection or a combination of parameters including the difference between the chest right and left deflections, were all developed based on given samples of Post Mortem Human Subject (PMHS). However, they were not validated against independent data and they are not always consistent with the observations from field data analysis. For this reason, 8 additional PMHS and matching THOR tests were carried out to assess the ability of the criteria to predict risks. Accident investigations showed that a reduction of the belt loads reduces the risk of rib fractures. Two configurations with different levels of force limitation were therefore chosen. A configuration representing an average European vehicle was chosen as a reference. It consists of a 3-point belt with a 3.5 kN and then 2 kN digressive limiter, combined with a 54-liter airbag. For better reproducibility and durability, the tests were performed with a pre-inflated bag and a semi-rigid seat. In this first configuration, the THOR dummy had a maximum resulting deflection of 43 mm. To differentiate the criteria, the second configuration was chosen such that it resulted in about the same deflection on the THOR dummy, but with a 5 kN belt force limitation combined with a lower pressure airbag. To reach this target of 43 mm, the pulse severity was lowered. Some criteria were higher in this second configuration, which allows them to be distinguished from the maximum deflection criterion. Four tests on four PMHS were performed in each configuration. The injury assessments showed that the total number of fractures was almost the same in both configurations, but that the number of separated fractures was greater in the 5 kN configuration. 25% of the subjects sustained AIS >3 injuries related to the number of displaced fractures in the 3.5/2 kN load limitation configuration. The result increased to 75% in the 5kN configuration. In total, 8 PMHS and the matching THOR tests were performed and used to assess the ability of the thoracic criteria to predict rib fractures in 2 types of chest loading configurations. The test results did not allow to conclude on the relevance of the criteria measured on the THOR dummy for the total number of rib fractures identified at autopsy (NFR). However, clearly different assessments for separated rib fractures (NSFR), make it possible to differentiate the criteria. The maximum resultant deflection failed to properly predict separated rib fractures while other criteria that include the left-to-right rib deflection difference did.</p>","PeriodicalId":35289,"journal":{"name":"Stapp car crash journal","volume":"63 ","pages":"219-305"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37853284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents the development of a sensor suite that is used to measure the toeboard threedimensional (3D) dynamic deformation during a crash test, along with the methodology to use the sensor suite for toeboard measurement. The sensor suite consists of three high-speed cameras, which are firmly connected through a rigid metal frame. Two cameras, facing directly towards the toeboard, measure the shape of the toeboard through stereovision. The third camera, facing the ground, is equipped with a three-axis gyroscope and a three-axis accelerometer and localizes the sensor suite globally for removing the vibration of the sensor suite. The sensor suite was mounted onto the car through car seat mounting bolt holes, and a hole was made on the floor to let the downward camera see the ground. A pipeline using the data collected by the sensor suite is also introduced in this paper. A 56 km/h frontal barrier crash test was conducted to validate the capability of the sensor suite and a sled test was conducted to test the measuring accuracy of the purposed system. The results show that the proposed sensor suite identified its position and orientation, which allowed the removal of vibration of the stereo camera. The measuring accuracy, which is neither temporal nor positional, was 1.3 mm. The proposed methodology, as a result, has measured the global 3D deformation of the toeboard during crash with a measuring accuracy of 1.3mm.
{"title":"A Sensor Suite for Toeboard Three-Dimensional Deformation Measurement During Crash.","authors":"Mengyu Song, Cong Chen, Tomonari Furukawa, Azusa Nakata, Shinsuke Shibata","doi":"10.4271/2019-22-0014","DOIUrl":"https://doi.org/10.4271/2019-22-0014","url":null,"abstract":"<p><p>This paper presents the development of a sensor suite that is used to measure the toeboard threedimensional (3D) dynamic deformation during a crash test, along with the methodology to use the sensor suite for toeboard measurement. The sensor suite consists of three high-speed cameras, which are firmly connected through a rigid metal frame. Two cameras, facing directly towards the toeboard, measure the shape of the toeboard through stereovision. The third camera, facing the ground, is equipped with a three-axis gyroscope and a three-axis accelerometer and localizes the sensor suite globally for removing the vibration of the sensor suite. The sensor suite was mounted onto the car through car seat mounting bolt holes, and a hole was made on the floor to let the downward camera see the ground. A pipeline using the data collected by the sensor suite is also introduced in this paper. A 56 km/h frontal barrier crash test was conducted to validate the capability of the sensor suite and a sled test was conducted to test the measuring accuracy of the purposed system. The results show that the proposed sensor suite identified its position and orientation, which allowed the removal of vibration of the stereo camera. The measuring accuracy, which is neither temporal nor positional, was 1.3 mm. The proposed methodology, as a result, has measured the global 3D deformation of the toeboard during crash with a measuring accuracy of 1.3mm.</p>","PeriodicalId":35289,"journal":{"name":"Stapp car crash journal","volume":"63 ","pages":"331-342"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37853286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ultrasonic parking sensors are an active technology designed to alert drivers to the presence of objects behind their vehicle but not the presence of a human. The purpose of this study was therefore to ascertain if these sensor systems can successfully detect a human subject. We accordingly conducted experiments using four vehicles equipped with both rear-facing center and corner ultrasonic parking sensor systems to determine the detection distance between the vehicle and a 1-m tall, 75-mm diameter pipe, a child, an adult woman, and an adult man. The detection of human subjects was evaluated under front-facing and side-facing conditions behind each vehicle. The results indicate that for a front-facing and side-facing child, the center sensor detection distances were 50-84% and 32-64%, respectively, shorter than that of the pipe. For front-facing and side-facing adults, the center sensor detection distances were just less than or roughly equivalent to that of the pipe at 89-102% and 78-97%, respectively. A similar trend was seen for the corner sensors. Notably, under the side-facing condition, the sensor detection distances were slightly shorter for all subjects than under the front-facing condition. These results reveal that ultrasonic parking sensor systems can not only detect objects but also humans, indicating that ultrasonic sensors are an available countermeasure to prevent backover accidents involving pedestrians. To address the shorter detection distance of children, a combination of ultrasonic parking sensors with other systems, such as backup cameras, may be more effective for avoiding backover collisions.
{"title":"Pedestrian Detection During Vehicle Backing Maneuvers Using Ultrasonic Parking Sensors.","authors":"Yasuhiro Matsui, Naruyuki Hosokawa, Shoko Oikawa","doi":"10.4271/2019-22-0015","DOIUrl":"https://doi.org/10.4271/2019-22-0015","url":null,"abstract":"<p><p>Ultrasonic parking sensors are an active technology designed to alert drivers to the presence of objects behind their vehicle but not the presence of a human. The purpose of this study was therefore to ascertain if these sensor systems can successfully detect a human subject. We accordingly conducted experiments using four vehicles equipped with both rear-facing center and corner ultrasonic parking sensor systems to determine the detection distance between the vehicle and a 1-m tall, 75-mm diameter pipe, a child, an adult woman, and an adult man. The detection of human subjects was evaluated under front-facing and side-facing conditions behind each vehicle. The results indicate that for a front-facing and side-facing child, the center sensor detection distances were 50-84% and 32-64%, respectively, shorter than that of the pipe. For front-facing and side-facing adults, the center sensor detection distances were just less than or roughly equivalent to that of the pipe at 89-102% and 78-97%, respectively. A similar trend was seen for the corner sensors. Notably, under the side-facing condition, the sensor detection distances were slightly shorter for all subjects than under the front-facing condition. These results reveal that ultrasonic parking sensor systems can not only detect objects but also humans, indicating that ultrasonic sensors are an available countermeasure to prevent backover accidents involving pedestrians. To address the shorter detection distance of children, a combination of ultrasonic parking sensors with other systems, such as backup cameras, may be more effective for avoiding backover collisions.</p>","PeriodicalId":35289,"journal":{"name":"Stapp car crash journal","volume":"63 ","pages":"343-358"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37853287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David B Stark, Arrianna K Willis, Zach Eshelman, Yun-Seok Kang, Rakshit Ramachandra, John H Bolte, Matthew McCrink
Unmanned aircraft systems (UAS), commonly known as drones, are part of a new and budding industry in the United States. Economic and public benefits associated with UAS use across multiple commercial sectors are driving new regulations which alter the stringent laws currently restricting UAS flights over people. As new regulations are enacted and more UAS populate the national airspace, there is a need to both understand and quantify the risk associated with UAS impacts with the uninvolved public. The purpose of this study was to investigate the biomechanical response and injury outcomes of Post Mortem Human Surrogates (PMHS) subjected to UAS head impacts. For this work, PMHS were tested with differing UAS vehicles at multiple impact angles, locations and speeds. Using a custom designed launching device, UAS vehicles were accelerated into the frontal, parietal, or vertex portions of subjects' craniums at speeds up to 22 m/s. Of the 35 UAS impacts carried out, one AIS 2+ injury was observed: a 13 cm linear skull fracture resulting from a Phantom 3 impact. Additionally, injury risk curves used in automotive testing were found to over predict the risk of injury in UAS impact scenarios. Finally, localized skull deformation was observed during severe impacts; the effect that this deformation had on measured kinematics should be further evaluated. Overall, the study found that AIS 2+ head injuries may occur as a result of UAS impacts and that automotive injury metrics may not be able to accurately predict head injury risk in UAS impact scenarios.
{"title":"Human Response and Injury Resulting from Head Impacts with Unmanned Aircraft Systems.","authors":"David B Stark, Arrianna K Willis, Zach Eshelman, Yun-Seok Kang, Rakshit Ramachandra, John H Bolte, Matthew McCrink","doi":"10.4271/2019-22-0002","DOIUrl":"https://doi.org/10.4271/2019-22-0002","url":null,"abstract":"<p><p>Unmanned aircraft systems (UAS), commonly known as drones, are part of a new and budding industry in the United States. Economic and public benefits associated with UAS use across multiple commercial sectors are driving new regulations which alter the stringent laws currently restricting UAS flights over people. As new regulations are enacted and more UAS populate the national airspace, there is a need to both understand and quantify the risk associated with UAS impacts with the uninvolved public. The purpose of this study was to investigate the biomechanical response and injury outcomes of Post Mortem Human Surrogates (PMHS) subjected to UAS head impacts. For this work, PMHS were tested with differing UAS vehicles at multiple impact angles, locations and speeds. Using a custom designed launching device, UAS vehicles were accelerated into the frontal, parietal, or vertex portions of subjects' craniums at speeds up to 22 m/s. Of the 35 UAS impacts carried out, one AIS 2+ injury was observed: a 13 cm linear skull fracture resulting from a Phantom 3 impact. Additionally, injury risk curves used in automotive testing were found to over predict the risk of injury in UAS impact scenarios. Finally, localized skull deformation was observed during severe impacts; the effect that this deformation had on measured kinematics should be further evaluated. Overall, the study found that AIS 2+ head injuries may occur as a result of UAS impacts and that automotive injury metrics may not be able to accurately predict head injury risk in UAS impact scenarios.</p>","PeriodicalId":35289,"journal":{"name":"Stapp car crash journal","volume":"63 ","pages":"29-64"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37852841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Philippe Petit, Xavier Trosseille, Jérome Uriot, David Poulard, Pascal Potier, Pascal Baudrit, Sabine Compigne, Masato Kunisada, Kenji Tsurui
Far side has been identified in the literature as a potential cause of numerous injuries and fatalities. Euro NCAP developed a far side test protocol to be performed to assess adult protection. A monitoring phase was undertaken between January 2018 and December 2019, and the far side assessment will become part of the rating for all vehicles launched in 2020 onward. A test buck was developed and 6 paired WorldSID / Post Mortem Human Subjects (PMHS) were subjected to the test protocol proposed by Euro NCAP to contribute to the development of limits. The buck consisted of a rigid seat and a rigid central console covered with 50 mm of Ethafoam TM 180 with a density of 16 kg/m3. The buck was mounted on the sled with an angle of 75° between the X axis of the vehicle and the X axis of the sled. The peak head excursion was compared between PMHS and the WorldSID dummy. It was found reasonably similar. However, the dummy repeatability was found to be poor. Out of 6 tests conducted on 6 PMHS, 2 specimens sustained AIS3 and, 3 specimens AIS2 cervical spine injuries, 3 specimens sustained AIS3, 1 AIS2 and 1 AIS1 thoracic injuries, and 2 specimens sustained AIS2 abdominal injuries. The peak values recorded on the dummy according to the Euro NCAP protocol were compared with the injury assessments of the PMHS tests. In the configuration used, which includes a central console, the hard thorax injury prediction was found to be excellent. For the neck injury prediction, the data were merged with similar results available in the literature and an Injury Risk Curve was proposed as a derivative from the curve published by Mertz et al. (2003) for neck extension.
在文献中,远侧已被确定为许多伤害和死亡的潜在原因。欧洲NCAP制定了一项评估成人保护的远侧测试方案。2018年1月至2019年12月期间进行了监测阶段,远端评估将成为2020年以后推出的所有车辆评级的一部分。开发了一个测试buck,并对6对WorldSID / Post - Mortem Human Subjects (PMHS)进行了Euro NCAP提出的测试方案,以促进限值的制定。buck由一个刚性座椅和一个刚性中控台组成,上面覆盖了50mm密度为16 kg/m3的Ethafoam TM 180。buck以车辆X轴与雪橇X轴之间的75°夹角安装在雪橇上。比较PMHS与WorldSID假人的峰头偏移。人们发现它们相当相似。然而,假人的重复性很差。6例PMHS共进行6次试验,其中2例为AIS3型,3例为AIS2型颈椎损伤,3例为AIS3型,1例为AIS2型,1例为AIS1型胸椎损伤,2例为AIS2型腹部损伤。根据欧洲NCAP方案在假人上记录的峰值与PMHS试验的损伤评估进行比较。在使用的配置中,包括一个中控台,硬胸损伤预测被发现是很好的。对于颈部损伤预测,将数据与文献中类似的结果合并,并提出了损伤风险曲线,作为Mertz等人(2003)发表的颈部伸展曲线的导数。
{"title":"Far Side Impact Injury Threshold Recommendations Based on 6 Paired WorldSID / Post-Mortem Human Subjects Tests.","authors":"Philippe Petit, Xavier Trosseille, Jérome Uriot, David Poulard, Pascal Potier, Pascal Baudrit, Sabine Compigne, Masato Kunisada, Kenji Tsurui","doi":"10.4271/2019-22-0005","DOIUrl":"https://doi.org/10.4271/2019-22-0005","url":null,"abstract":"<p><p>Far side has been identified in the literature as a potential cause of numerous injuries and fatalities. Euro NCAP developed a far side test protocol to be performed to assess adult protection. A monitoring phase was undertaken between January 2018 and December 2019, and the far side assessment will become part of the rating for all vehicles launched in 2020 onward. A test buck was developed and 6 paired WorldSID / Post Mortem Human Subjects (PMHS) were subjected to the test protocol proposed by Euro NCAP to contribute to the development of limits. The buck consisted of a rigid seat and a rigid central console covered with 50 mm of Ethafoam TM 180 with a density of 16 kg/m3. The buck was mounted on the sled with an angle of 75° between the X axis of the vehicle and the X axis of the sled. The peak head excursion was compared between PMHS and the WorldSID dummy. It was found reasonably similar. However, the dummy repeatability was found to be poor. Out of 6 tests conducted on 6 PMHS, 2 specimens sustained AIS3 and, 3 specimens AIS2 cervical spine injuries, 3 specimens sustained AIS3, 1 AIS2 and 1 AIS1 thoracic injuries, and 2 specimens sustained AIS2 abdominal injuries. The peak values recorded on the dummy according to the Euro NCAP protocol were compared with the injury assessments of the PMHS tests. In the configuration used, which includes a central console, the hard thorax injury prediction was found to be excellent. For the neck injury prediction, the data were merged with similar results available in the literature and an Injury Risk Curve was proposed as a derivative from the curve published by Mertz et al. (2003) for neck extension.</p>","PeriodicalId":35289,"journal":{"name":"Stapp car crash journal","volume":"63 ","pages":"127-146"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37852844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The EuroSID-2re (ES-2re) is an Anthropometric Test Device (ATD) from the automotive domain designed for lateral impact. Since the 2000's, it has also been used by NATO armies to assess the risk of injury to armored vehicles occupants submitted to an Improvised Explosive Device (IED) attack. The resulting loading conditions from an explosion can vary a lot in term of impact velocity and duration. They range from high velocity impacts (~28 m/s), characterized by a short duration (~10 ms) corresponding to cases where the panel deforms under an explosion, to low velocity impacts (~4 m/s), ch aracterized by a long duration (~50 ms) similar to the automotive domain. The goal of the study is to develop a shoulder injury criterion for the EuroSID- 2re that is relevant over the whole loading conditions spectrum of the military domain. For that purpose, thirty-three laboratory ES-2re tests are conducted to replicate four PMHS shoulder impactor test series from the literature. Each test series corresponds to a different loading condition in term of impact velocity and duration: [28 m/s, 3 ms], [14 m/s, 9 ms], [7 m/s, 30 ms], [4 m/s, 50 ms]. The injury result (AIS 2015 scale) of each PMHS test is paired with the shoulder sensor force response signal of the corresponding ES-2re test, resulting in a sample of 75 paired-data. The proposed injury criterion resulting from the sample analysis is the straightened peak force Fs, which is an estimate of the peak of the external force applied to the shoulder. This criterion combines two metrics from the response signal of the shoulder force sensor Y-axis of the ES-2re ATD: the initial slope (S) and the peak (Fmax). The threshold value for a given injury risk depends on the duration of the impact: it is higher for the shorter duration. Thus, a third metric should be extracted from the ES-2re shoulder load cell: the duration of the force T. The present study proposes three force-duration threshold curves Fs=f(T) for low, medium, and high risks of shoulder AI2+ injury.
{"title":"A Shoulder Injury Criterion for the EuroSID-2re Applicable in a Large Loading Condition Spectrum of the Military Domain.","authors":"Matthieu Lebarbé, Pascal Baudrit, Denis Lafont","doi":"10.4271/2019-22-0006","DOIUrl":"https://doi.org/10.4271/2019-22-0006","url":null,"abstract":"<p><p>The EuroSID-2re (ES-2re) is an Anthropometric Test Device (ATD) from the automotive domain designed for lateral impact. Since the 2000's, it has also been used by NATO armies to assess the risk of injury to armored vehicles occupants submitted to an Improvised Explosive Device (IED) attack. The resulting loading conditions from an explosion can vary a lot in term of impact velocity and duration. They range from <i>high velocity impacts</i> (~28 m/s), characterized by a short duration (~10 ms) corresponding to cases where the panel deforms under an explosion, to <i>low velocity impacts</i> (~4 m/s), ch aracterized by a long duration (~50 ms) similar to the automotive domain. The goal of the study is to develop a shoulder injury criterion for the EuroSID- 2re that is relevant over the whole loading conditions spectrum of the military domain. For that purpose, thirty-three laboratory ES-2re tests are conducted to replicate four PMHS shoulder impactor test series from the literature. Each test series corresponds to a different loading condition in term of impact velocity and duration: [28 m/s, 3 ms], [14 m/s, 9 ms], [7 m/s, 30 ms], [4 m/s, 50 ms]. The injury result (AIS 2015 scale) of each PMHS test is paired with the shoulder sensor force response signal of the corresponding ES-2re test, resulting in a sample of 75 paired-data. The proposed injury criterion resulting from the sample analysis is the straightened peak force Fs, which is an estimate of the peak of the external force applied to the shoulder. This criterion combines two metrics from the response signal of the shoulder force sensor Y-axis of the ES-2re ATD: the initial slope (S) and the peak (F<sub>max</sub>). The threshold value for a given injury risk depends on the duration of the impact: it is higher for the shorter duration. Thus, a third metric should be extracted from the ES-2re shoulder load cell: the duration of the force T. The present study proposes three force-duration threshold curves Fs=f(T) for low, medium, and high risks of shoulder AI2+ injury.</p>","PeriodicalId":35289,"journal":{"name":"Stapp car crash journal","volume":"63 ","pages":"147-176"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37852845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marco Benedetti, Kathleen D Klinich, Miriam A Manary, Carol A C Flannagan
Current recommendations for restraining child occupants are based on biomechanical testing and data from national and international field studies primarily conducted prior to 2011. We hypothesized that analysis to identify factors associated with pediatric injury in motor-vehicle crashes using a national database of more recent police-reported crashes in the United States involving children under age 13 where type of child restraint system (CRS) is recorded would support previous recommendations. Weighted data were extracted from the National Automotive Sampling System General Estimates System (NASS-GES) for crash years 2010 to 2015. Injury outcomes were grouped as CO (possible and no injury) or KAB (killed, incapacitating injury, nonincapacitating injury). Restraint was characterized as optimal, suboptimal, or unrestrained based on current best practice recommendations. Analysis used survey methods to identify factors associated with injury. Factors with significant effect on pediatric injury risk include restraint type, child age, driver injury, driver alcohol use, seating position, and crash direction. Compared to children using optimal restraint, unrestrained children have 4.9 (13-year-old) to 5.6 (< 1-year-old) times higher odds of injury, while suboptimally restrained children have 1.1 (13-year-old) to 1.9 (< 1-year-old) times higher odds of injury. As indicated by the differences in odds ratios, effects of restraint type attenuate with age. Results support current best practice recommendations to use each stage of child restraint (rear-facing CRS, forward-facing harnessed CRS, belt-positioning booster seat, lap and shoulder belt) as long as possible before switching to the next step.
{"title":"Factors Affecting Child Injury Risk in Motor-Vehicle Crashes.","authors":"Marco Benedetti, Kathleen D Klinich, Miriam A Manary, Carol A C Flannagan","doi":"10.4271/2019-22-0008","DOIUrl":"https://doi.org/10.4271/2019-22-0008","url":null,"abstract":"<p><p>Current recommendations for restraining child occupants are based on biomechanical testing and data from national and international field studies primarily conducted prior to 2011. We hypothesized that analysis to identify factors associated with pediatric injury in motor-vehicle crashes using a national database of more recent police-reported crashes in the United States involving children under age 13 where type of child restraint system (CRS) is recorded would support previous recommendations. Weighted data were extracted from the National Automotive Sampling System General Estimates System (NASS-GES) for crash years 2010 to 2015. Injury outcomes were grouped as CO (possible and no injury) or KAB (killed, incapacitating injury, nonincapacitating injury). Restraint was characterized as optimal, suboptimal, or unrestrained based on current best practice recommendations. Analysis used survey methods to identify factors associated with injury. Factors with significant effect on pediatric injury risk include restraint type, child age, driver injury, driver alcohol use, seating position, and crash direction. Compared to children using optimal restraint, unrestrained children have 4.9 (13-year-old) to 5.6 (< 1-year-old) times higher odds of injury, while suboptimally restrained children have 1.1 (13-year-old) to 1.9 (< 1-year-old) times higher odds of injury. As indicated by the differences in odds ratios, effects of restraint type attenuate with age. Results support current best practice recommendations to use each stage of child restraint (rear-facing CRS, forward-facing harnessed CRS, belt-positioning booster seat, lap and shoulder belt) as long as possible before switching to the next step.</p>","PeriodicalId":35289,"journal":{"name":"Stapp car crash journal","volume":"63 ","pages":"195-211"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37852847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yun-Seok Kang, John H Bolte, Jason Stammen, Kevin Moorhouse, Amanda M Agnew
Thoracic injuries are frequently observed in motor vehicle crashes, and rib fractures are the most common of those injuries. Thoracic response targets have previously been developed from data obtained from post-mortem human subject (PMHS) tests in frontal loading conditions, most commonly of mid-size males. Traditional scaling methods are employed to identify differences in thoracic response for various demographic groups, but it is often unknown if these applications are appropriate, especially considering the limited number of tested PMHS from which those scaling factors originate. Therefore, the objective of this study was to establish a new scaling approach for generating age-, sex-, and body size- dependent thoracic responses utilizing structural properties of human ribs from direct testing of various demographics. One-hundred forty-seven human ribs (140 adult; 7 pediatric) from 132 individuals (76 male; 52 female; 4 pediatric) ranging in age from 6 to 99 years were included in this study. Ribs were tested at 2 m/s to failure in a frontal impact scenario. Force and displacement for individual ribs were used to develop new scaling factors, with a traditional mid-size biomechanical target as a baseline response. This novel use of a large, varied dataset of dynamic whole rib responses offers vast possibilities to utilize existing biomechanical data in creative ways to reduce thoracic injuries in diverse vehicle occupants.
{"title":"A Novel Approach to Scaling Age-, Sex-, and Body Size-Dependent Thoracic Responses using Structural Properties of Human Ribs.","authors":"Yun-Seok Kang, John H Bolte, Jason Stammen, Kevin Moorhouse, Amanda M Agnew","doi":"10.4271/2019-22-0013","DOIUrl":"https://doi.org/10.4271/2019-22-0013","url":null,"abstract":"<p><p>Thoracic injuries are frequently observed in motor vehicle crashes, and rib fractures are the most common of those injuries. Thoracic response targets have previously been developed from data obtained from post-mortem human subject (PMHS) tests in frontal loading conditions, most commonly of mid-size males. Traditional scaling methods are employed to identify differences in thoracic response for various demographic groups, but it is often unknown if these applications are appropriate, especially considering the limited number of tested PMHS from which those scaling factors originate. Therefore, the objective of this study was to establish a new scaling approach for generating age-, sex-, and body size- dependent thoracic responses utilizing structural properties of human ribs from direct testing of various demographics. One-hundred forty-seven human ribs (140 adult; 7 pediatric) from 132 individuals (76 male; 52 female; 4 pediatric) ranging in age from 6 to 99 years were included in this study. Ribs were tested at 2 m/s to failure in a frontal impact scenario. Force and displacement for individual ribs were used to develop new scaling factors, with a traditional mid-size biomechanical target as a baseline response. This novel use of a large, varied dataset of dynamic whole rib responses offers vast possibilities to utilize existing biomechanical data in creative ways to reduce thoracic injuries in diverse vehicle occupants.</p>","PeriodicalId":35289,"journal":{"name":"Stapp car crash journal","volume":"63 ","pages":"307-329"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37853285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhou Zhou, Xiaogai Li, Svein Kleiven, Warren N Hardy
Brain strain secondary to head impact or inertial loading is closely associated with pathologic observations in the brain. The only experimental brain strain dataset under loadings close to traumatic levels was calculated by imposing the experimentally measured motion of markers embedded in the brain to an auxiliary model formed by triad elements (Hardy et al., 2007). However, fidelity of the calculated strain as well as the suitability of using triad elements for three-dimensional (3D) strain estimation remains to be verified. Therefore, this study proposes to use tetrahedron elements as a new approach to estimate the brain strain. Fidelity of this newly-proposed approach along with the previous triad-based approach is evaluated with the aid of three independently-developed finite element (FE) head models by numerically replicating the experimental impacts and strain estimation procedures. Strain in the preselected brain elements obtained from the whole head simulation exhibits good correlation with its tetra estimation and exceeds its triad estimation, indicating that the tetra approach more accurately estimates the strain in the preselected region. The newly calculated brain strain curves using tetra elements provide better approximations for the 3D experimental brain deformation and can be used for strain validation of FE models of human head.
{"title":"Brain Strain from Motion of Sparse Markers.","authors":"Zhou Zhou, Xiaogai Li, Svein Kleiven, Warren N Hardy","doi":"10.4271/2019-22-0001","DOIUrl":"https://doi.org/10.4271/2019-22-0001","url":null,"abstract":"<p><p>Brain strain secondary to head impact or inertial loading is closely associated with pathologic observations in the brain. The only experimental brain strain dataset under loadings close to traumatic levels was calculated by imposing the experimentally measured motion of markers embedded in the brain to an auxiliary model formed by triad elements (Hardy et al., 2007). However, fidelity of the calculated strain as well as the suitability of using triad elements for three-dimensional (3D) strain estimation remains to be verified. Therefore, this study proposes to use tetrahedron elements as a new approach to estimate the brain strain. Fidelity of this newly-proposed approach along with the previous triad-based approach is evaluated with the aid of three independently-developed finite element (FE) head models by numerically replicating the experimental impacts and strain estimation procedures. Strain in the preselected brain elements obtained from the whole head simulation exhibits good correlation with its tetra estimation and exceeds its triad estimation, indicating that the tetra approach more accurately estimates the strain in the preselected region. The newly calculated brain strain curves using tetra elements provide better approximations for the 3D experimental brain deformation and can be used for strain validation of FE models of human head.</p>","PeriodicalId":35289,"journal":{"name":"Stapp car crash journal","volume":"63 ","pages":"1-27"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37851865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jennifer L Yaek, John M Cavanaugh, Stephen W Rouhana
There has been recent progress over the past 10 years in research comparing 6-year-old thoracic and abdominal response of pediatric volunteers, pediatric post mortem human subjects (PMHS), animal surrogates, and 6-year-old ATDs. Although progress has been made to guide scaling laws of adult to pediatric thorax and abdomen data for use in ATD design and development of finite element models, further effort is needed, particularly with respect to lateral impacts. The objective of the current study was to use the impact response data of age equivalent swine from Yaek et al. (2018) to assess the validity of scaling laws used to develop lateral impact response corridors from adult porcine surrogate equivalents (PSE) to the 3-year-old, 6-year-old, and 10-year-old for the thorax and abdominal body regions. Lateral impact response corridors were created from 50th adult male PSE pendulum lateral impact T1, T14, and L6 accelerations and pendulum impact force time histories for the thorax and abdomen testing performed. The ISO 9790 scaling technique using length, mass, and elastic modulus scale factor formulas were used in conjunction with measured swine parameters to calculate scale factors for the PSE. In addition to calculation of pertinent test scale factors, response ratios for the pendulum impact tests were calculated. The scaling factors and response ratios determined for the porcine surrogates were compared to the already established ISO human lateral pendulum impact response ratios to determine whether a consistent pattern over the age levels described for the two sets of data (human and swine) exists. The actual lateral impact pendulum data, for both thoracic and abdominal regions, increases in magnitude and time duration from the 3-year-old PSE up to the 50th male PSE. This increase in magnitude and time duration is comparable to the human response corridors developed based on an impulse-momentum analysis and the elastic bending modulus derived from human skull bone. This pattern in the human impact response corridors was observed in the response ratio values and the swine response data. Based on the current study's findings, when utilizing the elastic modulus of human skull bone presented previously in research, thoracic and abdominal lateral pendulum impact response of PSE follows the general scaling laws, based on the impulse-momentum spring-mass model. The thoracic and abdominal lateral pendulum force impact response of PSE also follows the human scaled impact response corridors for lateral pendulum impact testing presented in previous research. The overall findings of the current study confirm, through actual swine testing of appropriate weight porcine surrogates, that scaling laws are applicable from the midsized-male adult down to the 3-year-old age level using human skull elastic modulus values established in previous research.
{"title":"Response Ratio Development for Lateral Pendulum Impact with Porcine Thorax and Abdomen Surrogate Equivalents.","authors":"Jennifer L Yaek, John M Cavanaugh, Stephen W Rouhana","doi":"10.4271/2019-22-0007","DOIUrl":"https://doi.org/10.4271/2019-22-0007","url":null,"abstract":"<p><p>There has been recent progress over the past 10 years in research comparing 6-year-old thoracic and abdominal response of pediatric volunteers, pediatric post mortem human subjects (PMHS), animal surrogates, and 6-year-old ATDs. Although progress has been made to guide scaling laws of adult to pediatric thorax and abdomen data for use in ATD design and development of finite element models, further effort is needed, particularly with respect to lateral impacts. The objective of the current study was to use the impact response data of age equivalent swine from Yaek et al. (2018) to assess the validity of scaling laws used to develop lateral impact response corridors from adult porcine surrogate equivalents (PSE) to the 3-year-old, 6-year-old, and 10-year-old for the thorax and abdominal body regions. Lateral impact response corridors were created from 50<sup>th</sup> adult male PSE pendulum lateral impact T1, T14, and L6 accelerations and pendulum impact force time histories for the thorax and abdomen testing performed. The ISO 9790 scaling technique using length, mass, and elastic modulus scale factor formulas were used in conjunction with measured swine parameters to calculate scale factors for the PSE. In addition to calculation of pertinent test scale factors, response ratios for the pendulum impact tests were calculated. The scaling factors and response ratios determined for the porcine surrogates were compared to the already established ISO human lateral pendulum impact response ratios to determine whether a consistent pattern over the age levels described for the two sets of data (human and swine) exists. The actual lateral impact pendulum data, for both thoracic and abdominal regions, increases in magnitude and time duration from the 3-year-old PSE up to the 50<sup>th</sup> male PSE. This increase in magnitude and time duration is comparable to the human response corridors developed based on an impulse-momentum analysis and the elastic bending modulus derived from human skull bone. This pattern in the human impact response corridors was observed in the response ratio values and the swine response data. Based on the current study's findings, when utilizing the elastic modulus of human skull bone presented previously in research, thoracic and abdominal lateral pendulum impact response of PSE follows the general scaling laws, based on the impulse-momentum spring-mass model. The thoracic and abdominal lateral pendulum force impact response of PSE also follows the human scaled impact response corridors for lateral pendulum impact testing presented in previous research. The overall findings of the current study confirm, through actual swine testing of appropriate weight porcine surrogates, that scaling laws are applicable from the midsized-male adult down to the 3-year-old age level using human skull elastic modulus values established in previous research.</p>","PeriodicalId":35289,"journal":{"name":"Stapp car crash journal","volume":"63 ","pages":"177-193"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37852846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}