Academic Department of Military Surgery and Trauma, Royal Centre for Defence Medicine, Birmingham, UK
Department of Bioengineering, Imperial College London, London, UK.
BMJ Mil Health. 2022 Oct;168(5):395-398. doi: 10.1136/bmjmilitary-2021-001833. Epub 2021 Jun 15.
Modern military combat helmets vary in their shapes and features, but all are designed to protect the head from traumatic brain injury. Recent recommendations for protection against energised projectiles that are characteristic of secondary blast injury is to ensure coverage of both the brain and brainstem.
Graphical representations of essential coverage of the head (cerebral hemispheres, cerebellum and brainstem) within an anthropometrically sized model were superimposed over two standard coverage helmets (VIRTUS helmet, Advanced Combat Helmet (ACH)) and two 'high-cut' helmets (a Dismounted Combat Helmet (DCH)) and Combat Vehicle Crewman (CVC) helmet), both of which are designed to be worn with communications devices. Objective shotline coverage from representative directions of projectile travel (-30 to +30 degrees) was determined using the Coverage of Armour Tool (COAT).
VIRTUS and ACH demonstrated similar overall coverage (68.7% and 69.5%, respectively), reflecting their similar shell shapes. ACH has improved coverage from below compared with VIRTUS (23.3% vs 21.7%) due to its decreased standoff from the scalp. The 'high-cut' helmets (DCH and CVC) had reduced overall coverage (57.9% and 52.1%), which was most pronounced from the side.
Both the VIRTUS and ACH helmets provide excellent overall coverage of the brain and brainstem against ballistic threats. Coverage of both would be improved at the rear by using a nape protector and the front using a visor. This is demonstrated with the analysis of the addition of the nape protector in the VIRTUS system. High-cut helmets provide significantly reduced coverage from the side of the head, as the communication devices they are worn with are not designed to provide protection from ballistic threats. Unless absolutely necessary, it is therefore recommended that high-cut helmets be worn only by those users with defined specific requirements, or where the risk of injury from secondary blast is low.
现代军用战斗头盔在形状和特点上有所不同，但都是为了保护头部免受创伤性脑损伤。最近对防止与二次爆炸损伤有关的带电射弹的保护建议是确保大脑和脑干都得到覆盖。
在人体模型中，对头（大脑半球、小脑和脑干）的基本覆盖范围进行图形表示，然后将其叠加在两个标准覆盖头盔（VIRTUS 头盔、先进战斗头盔（ACH））和两个“高切”头盔（步兵头盔（DCH）和战斗车辆乘员头盔（CVC））上，这两个头盔都是为了佩戴通讯设备而设计的。使用装甲覆盖工具（COAT）确定来自代表性射弹行进方向（-30 度至+30 度）的客观射击线覆盖范围。
VIRTUS 和 ACH 的总体覆盖范围相似（分别为 68.7%和 69.5%），这反映了它们相似的外壳形状。ACH 由于与头皮的距离减小，因此下方的覆盖范围比 VIRTUS 有所改善（23.3%比 21.7%）。“高切”头盔（DCH 和 CVC）的总覆盖范围较小（57.9%和 52.1%），从侧面看最为明显。
VIRTUS 和 ACH 头盔都能为大脑和脑干提供极好的弹道威胁整体保护。通过在后脑勺使用护颈器和在前额使用遮阳板，可以改善后部的覆盖范围。VIRTUS 系统中添加护颈器的分析就证明了这一点。高切头盔从头部侧面提供的覆盖范围显著减少，因为与它们一起佩戴的通讯设备并非设计用于提供弹道威胁保护。除非绝对必要，否则建议只有那些有明确特定要求的使用者或二次爆炸伤害风险较低的使用者佩戴高切头盔。
