Purpose： Seatbelt use during pregnancy is important to improve maternal and fetal survival after motor vehicle collisions. However, because the rear seatbelt of a motor vehicle tends to make contact with the neck, ev...Purpose： Seatbelt use during pregnancy is important to improve maternal and fetal survival after motor vehicle collisions. However, because the rear seatbelt of a motor vehicle tends to make contact with the neck, even if it is adequately used, some pregnant women sitting in the rear seat opt not to fasten the belt. The purpose of this study is to explore seatbelt-neck contact for pregnant women sitting in the rear seat of a motor vehicle. Methods： We carried out an anthropometric study. Japanese women who were _〉30 weeks pregnant （n = 12） sat in the left side of the rear seat of a typical mid-size passenger sedan and fastened the seatbelt. Seating posture was investigated by measuring the coordinates of the anthropometric data points of the pregnant women （head, shoulder, hip joint, and knee joint）. The belt path was analyzed by measuring the clearance between the belt and the sternum or navel. Results： Among the 12 pregnant women at 33.9 week _＋ 3.3 week gestation, the shoulder belt deviated to the right side and subsequently contacted to the neck in four pregnant women （Contact group）. The height of the Contact group was significantly shorter than that of Non-contact group （152.3 cm ~ 3.0 cm vs. 159.0 cm ＋ 3.3 cm, p = 0.008）. Regarding the relative position of the seatbelt to the subject＇s body, the distances from the top of the sternum to the center of the shoulder belt were significantly shorter in Contact group （3.9 cm ~ 3.5 cm） than that in the Non-contact group （8.0 cm ~ 1.6 cm, p = 0.03）. However, no significant difference was found for the distance from the umbilicus to the center of the lap belt. Conclusion： Our findings show that because of short height and late term of pregnancy with protrusion of the abdomen, the shoulder belt deviates to the right or left, avoiding the protruded uterus, and subsequently makes contact with the neck. Seatbelt systems for rear seats need to be developed to improve passenger safety, especially for pregnant women.展开更多
This paper used the Hyper Mesh and LS-DYNA software to establish a dummy-seat finite element simulation model. The head, chest and neck injury of the dummy were analyzed respectively in the frontal impact and rear imp...This paper used the Hyper Mesh and LS-DYNA software to establish a dummy-seat finite element simulation model. The head, chest and neck injury of the dummy were analyzed respectively in the frontal impact and rear impact. It was indicated that modification of seat was needed to meet the requirements. The simulation results showed that the original model cannot provide effective protection for the occupants and need for structural improvements. According to the simulation results of deformation and stress conditions of the seat parts, the original seat structure was improved and optimized for four improvement schemes, including the structure optimization of the seat side panel, the center hinge, framework under the cushion and the backrest lock. The results indicated that the optimized seat improved the occupant protection performance by reducing occupant damage parameters compared with original seat, which illustrated that the optimization basically met the target.展开更多
文摘Purpose： Seatbelt use during pregnancy is important to improve maternal and fetal survival after motor vehicle collisions. However, because the rear seatbelt of a motor vehicle tends to make contact with the neck, even if it is adequately used, some pregnant women sitting in the rear seat opt not to fasten the belt. The purpose of this study is to explore seatbelt-neck contact for pregnant women sitting in the rear seat of a motor vehicle. Methods： We carried out an anthropometric study. Japanese women who were _〉30 weeks pregnant （n = 12） sat in the left side of the rear seat of a typical mid-size passenger sedan and fastened the seatbelt. Seating posture was investigated by measuring the coordinates of the anthropometric data points of the pregnant women （head, shoulder, hip joint, and knee joint）. The belt path was analyzed by measuring the clearance between the belt and the sternum or navel. Results： Among the 12 pregnant women at 33.9 week _＋ 3.3 week gestation, the shoulder belt deviated to the right side and subsequently contacted to the neck in four pregnant women （Contact group）. The height of the Contact group was significantly shorter than that of Non-contact group （152.3 cm ~ 3.0 cm vs. 159.0 cm ＋ 3.3 cm, p = 0.008）. Regarding the relative position of the seatbelt to the subject＇s body, the distances from the top of the sternum to the center of the shoulder belt were significantly shorter in Contact group （3.9 cm ~ 3.5 cm） than that in the Non-contact group （8.0 cm ~ 1.6 cm, p = 0.03）. However, no significant difference was found for the distance from the umbilicus to the center of the lap belt. Conclusion： Our findings show that because of short height and late term of pregnancy with protrusion of the abdomen, the shoulder belt deviates to the right or left, avoiding the protruded uterus, and subsequently makes contact with the neck. Seatbelt systems for rear seats need to be developed to improve passenger safety, especially for pregnant women.
文摘This paper used the Hyper Mesh and LS-DYNA software to establish a dummy-seat finite element simulation model. The head, chest and neck injury of the dummy were analyzed respectively in the frontal impact and rear impact. It was indicated that modification of seat was needed to meet the requirements. The simulation results showed that the original model cannot provide effective protection for the occupants and need for structural improvements. According to the simulation results of deformation and stress conditions of the seat parts, the original seat structure was improved and optimized for four improvement schemes, including the structure optimization of the seat side panel, the center hinge, framework under the cushion and the backrest lock. The results indicated that the optimized seat improved the occupant protection performance by reducing occupant damage parameters compared with original seat, which illustrated that the optimization basically met the target.
