Reducing the impact of traumatic brain injury with new helmet technology
Adults and children of all ages are susceptible to traumatic brain injury (TBI). Every time we climb a ladder, ride a bicycle, play a sport, or even ride in a car, we are at risk of sustaining a TBI. According to the CDC,1 the most common cause of TBI among all age groups is falls, followed by blows to the head and motor vehicle accidents. In our daily lives, most of us can take precautions when participating in activities that put us at risk for TBI, or even choose to avoid activities that carry high risk for brain injury. In fact, some reports suggest that youth participation in contact sports such as football has begun to decline2,3 in response to increasing evidence that TBI can have serious long-term consequences.
TBI is classified by severity (mild, moderate, or severe), and mild TBI (mTBI; commonly referred to as concussion) is the most prevalent. MTBIs are characterized by the presence of at least one of the following symptoms:
- Loss of consciousness for 30 minutes or less;
- Loss of memory from before or after the head injury, also known as post-traumatic amnesia;
- Any period of alteration of consciousness, such as feeling dazed and confused.
Much of the data available on the short- and long-term effects of mTBI is from populations for whom brain injuries are essentially inevitable, including professional athletes and military service members. While precautions can be taken to reduce the risk of injury, there is simply no way to totally eliminate incidents of head injury in professional football games or in the context of military theater. Accordingly, there is interest in developing technology that can help to reduce the impact of these head injury exposures, with the hope that head injury will be less likely to result in a concussion.
In recent years, there has been increased media attention on the long-term effects of repeated concussions over the course of a professional football career. As a result, advances in helmet technology have been at the forefront of technological advances aimed at reducing concussion. In a collaboration between engineers and neurosurgeons, the helmet company VICIS developed a helmet that is designed to reduce the severity of linear and rotational head impacts.4 The helmet has a multilayer structure that absorbs and responds dynamically to impact. The design includes a unique outer shell that is designed to deform, or change structure, in response to impact (similar to the design of a car bumper). The helmet also includes a dynamic inner layer that moves in all directions in response to impact to reduce force, as well as two inner liners that are designed to optimize fit.
Researchers at Virginia Tech have developed protocol for testing the effectiveness of technology such as that of the VICIS helmet.5 The Summation of Tests for the Analysis of Risk (STAR) has been used for several years to assess the safety of helmet technology, and it is now considered the gold standard for such evaluations. The STAR equation accounts for head injury exposure and injury risk and reports the effectiveness of a helmet in protecting against impacts at 24 theoretical locations. It was designed to mimic the testing criteria of the New Car Assessment Program (NCAP), a metric that assesses the safety of automobiles. Importantly, the STAR equation takes into account linear and angular head impacts, both of which are believed to contribute to development of concussion. When tested by the STAR equation, the VICIS helmet received a five-star rating and performed better than any other helmet.
Recently, the US Military announced that it is partnering with VICIS to launch efforts to incorporate technology used in the VICIS helmet into designing new combat helmets for use in military theater.6,7 As the current helmets are primarily designed to protect against risks associated with combat such as gunfire and shrapnel, one particular goal of the effort is to improve the protection against blunt-force impacts that do not occur on the battlefield, but rather occur during training. It is important to note that, because the mechanisms by which head impacts result in concussive symptoms are not well understood, further testing will be required to determine whether the VICIS helmet will actually reduce the rate of concussion in the field.
- Rowson, Steven, and Stefan M. Duma. "Development of the STAR evaluation system for football helmets: integrating player head impact exposure and risk of concussion." Annals of biomedical engineering 39.8 (2011): 2130-2140.