一份報告說,，美國軍方的先進戰(zhàn)斗頭盔（ACH）可能幾乎無法保護士兵免受沖擊引發(fā)的腦傷害,。Raul Radovitzky及其同事使用一種精密的三維計算機模型研究爆炸激波如何穿過人頭的顱骨、腦脊液以及柔軟的腦組織,。這組科學家發(fā)現(xiàn),，把空氣壓縮到正常的海平面壓力的10倍的一次前方爆炸把能量通過面部、顱骨和軟組織傳入未受保護的頭,。這些模擬證明了美國軍方的先進戰(zhàn)斗頭盔（ACH）在某種程度上延遲了這種沖擊波到達頭部,，但是只能稍微減輕對腦的壓力，因為大多數能量徑直穿過面部,。這些發(fā)現(xiàn)與此前的研究相矛盾,，此前的研究提出這些頭盔可能讓沖擊能量聚焦，并讓先進戰(zhàn)斗頭盔（ACH）的佩戴者的腦傷害加劇,。
沖擊引發(fā)的外傷性腦傷害是在伊拉克和阿富汗的士兵遭受的最常見的傷害,。這組作者建議說，配有優(yōu)化的面罩的保護性頭盔可能在未來更好地保護士兵免受沖擊引起的外傷性腦傷害,。（生物谷Bioon.com）
生物谷推薦英文摘要：
PNAS doi: 10.1073/pnas.1014786107
In silico investigation of intracranial blast mitigation with relevance to military traumatic brain injury
Michelle K. Nyeina, Amanda M. Jasona, Li Yua, Claudio M. Pitaa, John D. Joannopoulosb,1, David F. Moorec, and Raul A. Radovitzkya,1
aInstitute for Soldier Nanotechnologies, Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA 02139;
bInstitute for Soldier Nanotechnologies, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139; and
cDefense and Veterans Brain Injury Center, Walter Reed Army Medical Center, Washington, DC 20307
Blast-induced traumatic brain injury is the most prevalent military injury in Iraq and Afghanistan, yet little is known about the mechanical effects of blasts on the human head, and still less is known about how personal protective equipment affects the brain’s response to blasts. In this study we investigated the effect of the Advanced Combat Helmet (ACH) and a conceptual face shield on the propagation of stress waves within the brain tissue following blast events. We used a sophisticated computational framework for simulating coupled fluid–solid dynamic interactions and a three-dimensional biofidelic finite element model of the human head and intracranial contents combined with a detailed model of the ACH and a conceptual face shield. Simulations were conducted in which the unhelmeted head, head with helmet, and head with helmet and face shield were exposed to a frontal blast wave with incident overpressure of 10 atm. Direct transmission of stress waves into the intracranial cavity was observed in the unprotected head and head with helmet simulations. Compared to the unhelmeted head, the head with helmet experienced slight mitigation of intracranial stresses. This suggests that the existing ACH does not significantly contribute to mitigating blast effects, but does not worsen them either. By contrast, the helmet and face shield combination impeded direct transmission of stress waves to the face, resulting in a delay in the transmission of stresses to the intracranial cavity and lower intracranial stresses. This suggests a possible strategy for mitigating blast waves often associated with military concussion.
