Purpose:With the increasing level of automation in automobiles,the advent of autonomous vehicles hasreduced the tendency of drivers and passengers to focus on the task of driving.The increasing automation in automobil...Purpose:With the increasing level of automation in automobiles,the advent of autonomous vehicles hasreduced the tendency of drivers and passengers to focus on the task of driving.The increasing automation in automobiles reduced the drivers'and passengers'focus on driving,which allowed occupants tochoose a more relaxed and comfortable sitting position.Meanwhile,the occupant's sitting position wentfrom a frontal,upright position to a more relaxed and reclined one,which resulted in the existing restraint systems cannot to keep occupants safe and secure.This study aimed to determine the effects ofdifferent reclining states on occupants'lumbar and neck injuries.Methods:This is an original research on the field of automotive safety engineering.Occupants indifferent initial sitting positions(25°,35°,45°,and 55°)were adapted to changes in seat back angle andrestraint systems and placed in the same frontal impact environment.Neck injury indexes,lumbar axialcompression force and acceleration,as well as occupant dynamic response during the impact,werecompared in different sitting positions.The injury response and kinematic characteristics of occupants indifferent reclining positions were analyzed by the control variable method.Results:As the sitting angle increased,the occupant's head acceleration decreased,and the forward-leanangle decreased.Occupants in the standard sitting position had the greatest neck injury,with an Nij of0.95,and were susceptible to abbreviated injury scale 2+cervical medullary injuries.As the seatbackangle increased,the geometric position of the lumbar spine tended to be horizontal,and the impact loadtransmitted greater forces to the lumbar spine.The occupant's lumbar injury was greatest in the lyingposition,with a peak axial compression force on the lumbar region of 5.5 KN,which was 2.3 KN greaterthan in the standard sitting position.Conclusion:The study of occupant lumbar and neck injuries based on different recline states can providea theoretical basis for optimizing lumbar evaluation indexes,which is conducive to the understanding ofthe lumbar injury mechanism and the comprehensive consideration of occupant safety protection.展开更多
Chairs are the most common furniture in household environments,and reclining chairs specifically cater to the functional needs of the elderly.With the gradually increasing aging population,our preliminary research has...Chairs are the most common furniture in household environments,and reclining chairs specifically cater to the functional needs of the elderly.With the gradually increasing aging population,our preliminary research has revealed that current reclining chair designs often fail to align with the physical dimensions and needs of older adults.Many designs appear to prioritize technology over usability,resulting in a homogenous product landscape.Using statistical analysis and the weighted average method,an elderly-friendly reclining chair that considers height,depth,and width is designed.The final design aims to meet the psychological and physiological needs of self-care,semi-dependent,and fully dependent elderly individuals.Adhering to the“people-oriented”design philosophy and targeting“convenience and efficiency,”our ultimate goal is to create a reclining chair that helps the elderly lie down,stand up,and sit down with dignity.This innovative approach offers a new perspective for the market of aging-friendly furniture.展开更多
Background: Although evidence on the health effects of sedentary behavior(SB) has grown systematically in recent years, few developing countries have reported population levels of SB, especially in South America. Our ...Background: Although evidence on the health effects of sedentary behavior(SB) has grown systematically in recent years, few developing countries have reported population levels of SB, especially in South America. Our objective was to describe time spent sitting in a representative sample from Chile categorized by age, gender, educational level, and body mass index(BMI).Methods: A national health survey was conducted in Chile in a nationally representative sample(n = 5411) in 2009-2010. Sitting time(ST) was measured with the Global Physical Activity Questionnaire Version 2.Results: Data were from 5031 participants(43.26±0.41 years, mean±SE; 40.3% male). Overall, there were no gender differences in mean ST(men: 158.10±5.80 min/day, women 143.45±4.77 min/day; p = 0.05). ST was lower in those who lived in rural areas compared with urban areas(99.4 min/day vs. 160.0 min/day; p = 0.001). ST increased significantly with increasing BMI, but only in men(p = 0.009), and was positively related to years of education in both men and women(p < 0.0001).Conclusion: The findings were different from those reported in other countries and contexts, reinforcing the need for international surveillance and monitoring over time to inform policy makers. Differences in ST across different groups emphasize the need to develop tailored messages and interventions for reducing ST in different population subgroups.展开更多
Purpose:To judge the injury mode and injury severity of the real human body through the measured values of anthropomorphic test devices(ATD)injury indices,the mapping relationship of lumbar injury between ATD and huma...Purpose:To judge the injury mode and injury severity of the real human body through the measured values of anthropomorphic test devices(ATD)injury indices,the mapping relationship of lumbar injury between ATD and human body model(HBM)was explored.Methods:Through the ATD model and HBM simulation,the mapping relationship of lumbar injury between the 2 subjects was explored.The sled environment consisted of a semi-rigid seat with an adjustable seatback angle and a 3-point seat belt system with a seatback-mounted D-ring.Three seatback recline states of 25°,45°,and 65°were designed,and the seat pan angle was maintained at 15°.A 23 g,47 km/h pulse was used.The validity of the finite element model of the sled was verified by the comparison of ATD simulation and test results.ATD model was the test device for human occupant restraint for autonomous vehicles(THOR-AV)dummy model and HBM was the total human model for safety(THUMS)v6.1.The posture of the 2 models was adjusted to adapt to the 3 seat states.The lumbar response of THOR-AV and the mechanical and biomechanical data on L1-L5 vertebrae of THUMS were output,and the response relationship between THOR-AV and THUMS was descriptive statistically analyzed.Results:Both THOR-AV and THUMS were submarined in the 65°seatback angle case.With the change of seatback angle,the lumbar spine axial compression force(F_(z))of THOR-AV and THUMS changed in the similar trend.The maximum F_(z) ratio of THOR-AV to THUMS at 25°and 45°seatback angle cases were 1.6 and 1.7.The flexion moment(M_(y))and the time when the maximum M_(y) occurred in the 2 subjects were very different.In particular,the form of moment experienced by the L1-L5 vertebrae of THUMS also changed.The changing trend of M_(y) measured by THOR-AV over time can reflect the changing trend of maximum stress of L1 and L2 of THUMS.Conclusion:The F_(z) of ATD and HBM presents a certain proportional relationship,and there is a mapping relationship between the 2 subjects on F_(z).The mapping function can be further clarified by applying more pulses and adopting more seatback angles.It is difficult to map M_(y) directly because they are very different in ATD and HBM.The M_(y) of ATD and stress of HBM lumbar showed a similar change trend over time,and there may be a hidden mapping relationship.展开更多
基金This study was supported by the National Natural ScienceFoundation of China(52175084 and 52175085)the NaturalScience Foundation of Hebei Province(E2020202017).
文摘Purpose:With the increasing level of automation in automobiles,the advent of autonomous vehicles hasreduced the tendency of drivers and passengers to focus on the task of driving.The increasing automation in automobiles reduced the drivers'and passengers'focus on driving,which allowed occupants tochoose a more relaxed and comfortable sitting position.Meanwhile,the occupant's sitting position wentfrom a frontal,upright position to a more relaxed and reclined one,which resulted in the existing restraint systems cannot to keep occupants safe and secure.This study aimed to determine the effects ofdifferent reclining states on occupants'lumbar and neck injuries.Methods:This is an original research on the field of automotive safety engineering.Occupants indifferent initial sitting positions(25°,35°,45°,and 55°)were adapted to changes in seat back angle andrestraint systems and placed in the same frontal impact environment.Neck injury indexes,lumbar axialcompression force and acceleration,as well as occupant dynamic response during the impact,werecompared in different sitting positions.The injury response and kinematic characteristics of occupants indifferent reclining positions were analyzed by the control variable method.Results:As the sitting angle increased,the occupant's head acceleration decreased,and the forward-leanangle decreased.Occupants in the standard sitting position had the greatest neck injury,with an Nij of0.95,and were susceptible to abbreviated injury scale 2+cervical medullary injuries.As the seatbackangle increased,the geometric position of the lumbar spine tended to be horizontal,and the impact loadtransmitted greater forces to the lumbar spine.The occupant's lumbar injury was greatest in the lyingposition,with a peak axial compression force on the lumbar region of 5.5 KN,which was 2.3 KN greaterthan in the standard sitting position.Conclusion:The study of occupant lumbar and neck injuries based on different recline states can providea theoretical basis for optimizing lumbar evaluation indexes,which is conducive to the understanding ofthe lumbar injury mechanism and the comprehensive consideration of occupant safety protection.
基金Chongqing University of Engineering Internal Fund Key Project in Natural Sciences:Research on Spatial Syntax Parameters and Combination Patterns of Elderly Care Centers in Urban and Rural Communities from a Multidimensional Logical Perspective(Project No:XJXM202412014)。
文摘Chairs are the most common furniture in household environments,and reclining chairs specifically cater to the functional needs of the elderly.With the gradually increasing aging population,our preliminary research has revealed that current reclining chair designs often fail to align with the physical dimensions and needs of older adults.Many designs appear to prioritize technology over usability,resulting in a homogenous product landscape.Using statistical analysis and the weighted average method,an elderly-friendly reclining chair that considers height,depth,and width is designed.The final design aims to meet the psychological and physiological needs of self-care,semi-dependent,and fully dependent elderly individuals.Adhering to the“people-oriented”design philosophy and targeting“convenience and efficiency,”our ultimate goal is to create a reclining chair that helps the elderly lie down,stand up,and sit down with dignity.This innovative approach offers a new perspective for the market of aging-friendly furniture.
基金funded by the Ministry of Health, ChileNAF was supported by the Direccion de Cooperacion Internacional (26/2016), Universidad de La FronteraPMF was supported by the Direccion de Investigacion, Universidad de La Frontera (DIUFRO16-0110)
文摘Background: Although evidence on the health effects of sedentary behavior(SB) has grown systematically in recent years, few developing countries have reported population levels of SB, especially in South America. Our objective was to describe time spent sitting in a representative sample from Chile categorized by age, gender, educational level, and body mass index(BMI).Methods: A national health survey was conducted in Chile in a nationally representative sample(n = 5411) in 2009-2010. Sitting time(ST) was measured with the Global Physical Activity Questionnaire Version 2.Results: Data were from 5031 participants(43.26±0.41 years, mean±SE; 40.3% male). Overall, there were no gender differences in mean ST(men: 158.10±5.80 min/day, women 143.45±4.77 min/day; p = 0.05). ST was lower in those who lived in rural areas compared with urban areas(99.4 min/day vs. 160.0 min/day; p = 0.001). ST increased significantly with increasing BMI, but only in men(p = 0.009), and was positively related to years of education in both men and women(p < 0.0001).Conclusion: The findings were different from those reported in other countries and contexts, reinforcing the need for international surveillance and monitoring over time to inform policy makers. Differences in ST across different groups emphasize the need to develop tailored messages and interventions for reducing ST in different population subgroups.
基金supported by the National Natural Science Foundation of China(51621004)the Chongqing Doctor"Through Train"Scientific Research Project(CSTB2023NSCQ-BSX0011,CSTB2024NSCQ-BSX0014)+1 种基金the Natural Science Foundation of Hunan Province(2020JJ4184)Natural Science Foundation of Chongqing(CSTB2024NSCQ-MSX0684).
文摘Purpose:To judge the injury mode and injury severity of the real human body through the measured values of anthropomorphic test devices(ATD)injury indices,the mapping relationship of lumbar injury between ATD and human body model(HBM)was explored.Methods:Through the ATD model and HBM simulation,the mapping relationship of lumbar injury between the 2 subjects was explored.The sled environment consisted of a semi-rigid seat with an adjustable seatback angle and a 3-point seat belt system with a seatback-mounted D-ring.Three seatback recline states of 25°,45°,and 65°were designed,and the seat pan angle was maintained at 15°.A 23 g,47 km/h pulse was used.The validity of the finite element model of the sled was verified by the comparison of ATD simulation and test results.ATD model was the test device for human occupant restraint for autonomous vehicles(THOR-AV)dummy model and HBM was the total human model for safety(THUMS)v6.1.The posture of the 2 models was adjusted to adapt to the 3 seat states.The lumbar response of THOR-AV and the mechanical and biomechanical data on L1-L5 vertebrae of THUMS were output,and the response relationship between THOR-AV and THUMS was descriptive statistically analyzed.Results:Both THOR-AV and THUMS were submarined in the 65°seatback angle case.With the change of seatback angle,the lumbar spine axial compression force(F_(z))of THOR-AV and THUMS changed in the similar trend.The maximum F_(z) ratio of THOR-AV to THUMS at 25°and 45°seatback angle cases were 1.6 and 1.7.The flexion moment(M_(y))and the time when the maximum M_(y) occurred in the 2 subjects were very different.In particular,the form of moment experienced by the L1-L5 vertebrae of THUMS also changed.The changing trend of M_(y) measured by THOR-AV over time can reflect the changing trend of maximum stress of L1 and L2 of THUMS.Conclusion:The F_(z) of ATD and HBM presents a certain proportional relationship,and there is a mapping relationship between the 2 subjects on F_(z).The mapping function can be further clarified by applying more pulses and adopting more seatback angles.It is difficult to map M_(y) directly because they are very different in ATD and HBM.The M_(y) of ATD and stress of HBM lumbar showed a similar change trend over time,and there may be a hidden mapping relationship.
