A simplified finite element model of a human thorax had been developed for probing into the mechani- cal response in simple and complex blast environments. The human thorax model was first created by CT images with bl...A simplified finite element model of a human thorax had been developed for probing into the mechani- cal response in simple and complex blast environments. The human thorax model was first created by CT images with blast loading applied via a coupled arbitrary Lagrangian- Eulerian method, allowing for a variety of loads to be considered. The goal is to analyze the maximum stress distri- butions of lung tissue and peak inward thorax wall velocity and to know the possible regions and levels of lung injury. In parallel, a mathematical model has been modified from the Lobdell model to investigate the detailed percentage of lung injury at each level. The blast loadings around the human tho- rax were obtained from the finite element model, and were then applied in the mathematical model as the boundary con- ditions to predict the normalized work of the human thorax lung. The present results are found in agreement with the modified Bowen curves and the results predicted by Axels- son＇s model.展开更多
<strong>Objective:</strong> To explore the characteristics and mechanisms of serious injuries of chest caused by road traffic accidents. <strong>Methods:</strong> Totally 112 autopsy cases with...<strong>Objective:</strong> To explore the characteristics and mechanisms of serious injuries of chest caused by road traffic accidents. <strong>Methods:</strong> Totally 112 autopsy cases with chest injuries in the urban of Jingzhou road traffic accidents were collected. Systematic review and analysis of the general information, postmortem examinations and assessments of chest injury had carried out from Feb. 2016 to Mar. 2018. <strong>Results:</strong> Average age of the victims was 52.2 years and the ratio of male to female deaths was 2.39:1. The proportion of motor-cyclists and pedestrians increased significantly. The overwhelming majority of accident vehicles were motorcycles and bicycles. Fractures of ribs and pulmonary contusion were the most common injuries. Craniocerebral and abdominal injuries were the most common associated injuries. <strong>Conclusion:</strong> Fractures of ribs and pulmonary contusion were the most common features of fatal road traffic injuries, often associated with vitreoretinal damage and serious multiple damages. These features reflect the characteristics of great violence in traffic accidents, which provides the evidence of identification of violent injuries.展开更多
Appropriate management of penetrating trauma to the thorax requires knowledge of vulnating agents, as well as the principles of ballistic injury. The importance of the approach’s choice for surgical exploration of th...Appropriate management of penetrating trauma to the thorax requires knowledge of vulnating agents, as well as the principles of ballistic injury. The importance of the approach’s choice for surgical exploration of these injuries, and parietal damage, is an essential factor in decision making in the management and definition of the therapeutic strategy for these injuries. The authors report a clinical case of a penetrating traumatic ballistic wound of the thorax managed in a context of difficult diagnosis in the surgical Unit of the CHUPB.展开更多
Objective： To explore the relationship between the collision parameters of vehicle and the pedestrian thorax injury by establishing the chest simulation models in car-pedestrian collision at different velocities and ...Objective： To explore the relationship between the collision parameters of vehicle and the pedestrian thorax injury by establishing the chest simulation models in car-pedestrian collision at different velocities and angles. Methods： 87 cases of vehicle-to-pedestrian accidents, with detailed injury information and determined vehicle impact parameters, were included. The severity of injury was scaled in line with the Abbreviated Injury Scale （AIS）. The chest biomechanical response parameters and change characteristics were obtained by using Hyperworks and LS-DYNA computing. Simulation analysis was applied to compare the characteristics of injuries. Results： When impact velocities at 25, 40 and 55 km/h, respectively, 1） the maximum values of thorax velocity criterion （VC） were for 0.29, 0.83 and 2.58 m/s; and at the same collision velocity, the thorax VC from the impact on pedestrian＇s front was successively greater than on his back and on his side; 2） the maximum values of peak stress on ribs were 154,177 and 209 MPa; and at the same velocity, peak stress values on ribs from the impact on pedestrian＇s side were greater than on his front and his back. Conclusion： There is a positive correlation between the severity and risk of thorax injury and the collision velocity and angle of car-thorax crashes. At the same velocity, it is of greater damage risk when the soft tissue of thorax under a front impact; and there is also a greater risk of ribs fracture under a side impact of the thorax. This result is of vital significance for diagnosis and protection of thorax collision injuries.展开更多
Objective:Fragment injury is a type of blast injury that is becoming more and more common in military campaigns and terrorist attacks.Numerical simulation methods investigating the formation of natural fragments and i...Objective:Fragment injury is a type of blast injury that is becoming more and more common in military campaigns and terrorist attacks.Numerical simulation methods investigating the formation of natural fragments and injuries to biological targets are expected to be developed.Methods:A cylindrical warhead model was established and the formation process of natural fragments was simulated using the approach of tied nodes with failure through the explicit finite element(FE)software of LS-DYNA.The interaction between the detonation product and the warhead shell was simulated using the fluidestructure interaction algorithm.A method to simulate the injury of natural fragments to a biological target was presented by transforming Lagrange elements into smooth particle hydrodynamics(SPH)particles after the natural fragments were successfully formed.A computational model of the human thorax was established to simulate the injury induced by natural fragments by the node-to-surface contact algorithm with erosion.Results:The discontinuous velocities of the warhead shell at different locations resulted in the formation of natural fragments with different sizes.The velocities of natural fragments increased rapidly at the initial stage and slowly after the warhead shell fractured.The initial velocities of natural fragments at the central part of the warhead shell were the largest,whereas those at both ends of the warhead shell were the smallest.The natural fragments resulted in bullet holes that were of the same shape as that of the fragments but slightly larger in size than the fragments in the human thorax after they penetrated through.Stress waves propagated in the ribs and enhanced the injury to soft tissues;additionally,ballistic pressure waves ahead of the natural fragments were also an injury factor to the soft tissues.Conclusion:The proposed method is effective in simulating the formation of natural fragments and their injury to biological targets.Moreover,this method will be beneficial for simulating the combined injuries of natural fragments and shock waves to biological targets.展开更多
文摘A simplified finite element model of a human thorax had been developed for probing into the mechani- cal response in simple and complex blast environments. The human thorax model was first created by CT images with blast loading applied via a coupled arbitrary Lagrangian- Eulerian method, allowing for a variety of loads to be considered. The goal is to analyze the maximum stress distri- butions of lung tissue and peak inward thorax wall velocity and to know the possible regions and levels of lung injury. In parallel, a mathematical model has been modified from the Lobdell model to investigate the detailed percentage of lung injury at each level. The blast loadings around the human tho- rax were obtained from the finite element model, and were then applied in the mathematical model as the boundary con- ditions to predict the normalized work of the human thorax lung. The present results are found in agreement with the modified Bowen curves and the results predicted by Axels- son＇s model.
文摘<strong>Objective:</strong> To explore the characteristics and mechanisms of serious injuries of chest caused by road traffic accidents. <strong>Methods:</strong> Totally 112 autopsy cases with chest injuries in the urban of Jingzhou road traffic accidents were collected. Systematic review and analysis of the general information, postmortem examinations and assessments of chest injury had carried out from Feb. 2016 to Mar. 2018. <strong>Results:</strong> Average age of the victims was 52.2 years and the ratio of male to female deaths was 2.39:1. The proportion of motor-cyclists and pedestrians increased significantly. The overwhelming majority of accident vehicles were motorcycles and bicycles. Fractures of ribs and pulmonary contusion were the most common injuries. Craniocerebral and abdominal injuries were the most common associated injuries. <strong>Conclusion:</strong> Fractures of ribs and pulmonary contusion were the most common features of fatal road traffic injuries, often associated with vitreoretinal damage and serious multiple damages. These features reflect the characteristics of great violence in traffic accidents, which provides the evidence of identification of violent injuries.
文摘Appropriate management of penetrating trauma to the thorax requires knowledge of vulnating agents, as well as the principles of ballistic injury. The importance of the approach’s choice for surgical exploration of these injuries, and parietal damage, is an essential factor in decision making in the management and definition of the therapeutic strategy for these injuries. The authors report a clinical case of a penetrating traumatic ballistic wound of the thorax managed in a context of difficult diagnosis in the surgical Unit of the CHUPB.
基金The Natural Science Foundation of China （Project number 31271006）, the Chongqing Natural Science Fund （Project number CSTC2012JJYS0004）.
文摘Objective： To explore the relationship between the collision parameters of vehicle and the pedestrian thorax injury by establishing the chest simulation models in car-pedestrian collision at different velocities and angles. Methods： 87 cases of vehicle-to-pedestrian accidents, with detailed injury information and determined vehicle impact parameters, were included. The severity of injury was scaled in line with the Abbreviated Injury Scale （AIS）. The chest biomechanical response parameters and change characteristics were obtained by using Hyperworks and LS-DYNA computing. Simulation analysis was applied to compare the characteristics of injuries. Results： When impact velocities at 25, 40 and 55 km/h, respectively, 1） the maximum values of thorax velocity criterion （VC） were for 0.29, 0.83 and 2.58 m/s; and at the same collision velocity, the thorax VC from the impact on pedestrian＇s front was successively greater than on his back and on his side; 2） the maximum values of peak stress on ribs were 154,177 and 209 MPa; and at the same velocity, peak stress values on ribs from the impact on pedestrian＇s side were greater than on his front and his back. Conclusion： There is a positive correlation between the severity and risk of thorax injury and the collision velocity and angle of car-thorax crashes. At the same velocity, it is of greater damage risk when the soft tissue of thorax under a front impact; and there is also a greater risk of ribs fracture under a side impact of the thorax. This result is of vital significance for diagnosis and protection of thorax collision injuries.
基金The work was funded by the National Science Foundation for Young Scientists of China(11902356)China Postdoctoral Science Foundation(2018M633715)+1 种基金Innovation and Cultivation Fund of the Sixth Medical Center of PLA General Hospital(No.CXPY201825)the Army Scientific Research(LB20182D040012).
文摘Objective:Fragment injury is a type of blast injury that is becoming more and more common in military campaigns and terrorist attacks.Numerical simulation methods investigating the formation of natural fragments and injuries to biological targets are expected to be developed.Methods:A cylindrical warhead model was established and the formation process of natural fragments was simulated using the approach of tied nodes with failure through the explicit finite element(FE)software of LS-DYNA.The interaction between the detonation product and the warhead shell was simulated using the fluidestructure interaction algorithm.A method to simulate the injury of natural fragments to a biological target was presented by transforming Lagrange elements into smooth particle hydrodynamics(SPH)particles after the natural fragments were successfully formed.A computational model of the human thorax was established to simulate the injury induced by natural fragments by the node-to-surface contact algorithm with erosion.Results:The discontinuous velocities of the warhead shell at different locations resulted in the formation of natural fragments with different sizes.The velocities of natural fragments increased rapidly at the initial stage and slowly after the warhead shell fractured.The initial velocities of natural fragments at the central part of the warhead shell were the largest,whereas those at both ends of the warhead shell were the smallest.The natural fragments resulted in bullet holes that were of the same shape as that of the fragments but slightly larger in size than the fragments in the human thorax after they penetrated through.Stress waves propagated in the ribs and enhanced the injury to soft tissues;additionally,ballistic pressure waves ahead of the natural fragments were also an injury factor to the soft tissues.Conclusion:The proposed method is effective in simulating the formation of natural fragments and their injury to biological targets.Moreover,this method will be beneficial for simulating the combined injuries of natural fragments and shock waves to biological targets.
