Nano-Composite Foam Sensor System in Football Helmets

Abstract

American football has both the highest rate of concussion incidences as well as the highest number of concussions of all contact sports due to both the number of athletes and nature of the sport. Recent research has linked concussions with long term health complications such as chronic traumatic encephalopathy and early onset Alzheimer's. Understanding the mechanical characteristics of concussive impacts is critical to help protect athletes from these debilitating diseases and is now possible using helmet-based sensor systems. To date, real time on-field measurement of head impacts has been almost exclusively measured by devices that rely on accelerometers or gyroscopes attached to the player's helmet, or embedded in a mouth guard. These systems monitor motion of the head or helmet, but do not directly measure impact energy. This paper evaluates the accuracy of a novel, multifunctional foam-based sensor that replaces a portion of the helmet foam to measure impact. All modified helmets were tested using a National Operating Committee Standards for Athletic Equipment-style drop tower with a total of 24 drop tests (4 locations with 6 impact energies). The impacts were evaluated using a headform, instrumented with a tri-axial accelerometer, mounted to a Hybrid III neck assembly. The resultant accelerations were evaluated for both the peak acceleration and the severity indices. These data were then compared to the voltage response from multiple Nano Composite Foam sensors located throughout the helmet. The foam sensor system proved to be accurate in measuring both the HIC and Gadd severity index, as well as peak acceleration while also providing additional details that were previously difficult to obtain, such as impact energy.

Design and Analysis of Electronic Wearables for Taekwondo Sports

“…At this region, the foam loses its linearity and the response is no longer linear. This is further supported by the manufacturers of the NCF sensor as they also mention that the response is not linear in the densification region in their article [62].…”

“…The fast pace at which technology is advancing requires the sports industry to adopt the latest technology and improve spectatorship and customer retention. We know from the introduction of this work that this is a significant factor that is known to be the downfall of of nickel nanoparticles and nickel coated carbon fiber that is added to the liquid components of polyurethane foam [62]. The generated charge then needs to be transmitted to the microcontroller for acquisition after an impact, and this is done by a conductive electrode.…”

“…The response of this NCF sensor depends on several factors such as impact area, impact duration, strain rate, total strain, however, the most important one is that it is dependent upon impact force and initial velocity. Both these factors significantly affect strain rate and therefore the higher strain will result in a larger NCF charge generation [62]. The inventors of this foam determined a linear correlation of the foam as long as it is in the plateau region and does not reach the densification region.…”

Wearables and the Medical Revolution

“…Wearables can inform ongoing or new symptoms, such as medication side effects or interactions, and may be able to provide automated just-in-time interventions. Additional benefits of wearable sensors in the field setting include their applicability in environments where rapid medical care is needed and often not readily available, for example, at the scene of accidents, in military settings, athletics and in resource-constrained environments (Figure 2) [36,[138][139][140]. Wearable and environmental sensors promise to improve information collection and transfer rapidly, potentially to off-site experts and specially designed algorithms enable automated and real-time medical decision support in time-and resource-constrained environments (Figure 2B).…”

Special Issue on the NCAA-DoD CARE Consortium Research

“…One study presented a novel foam-based technology for measuring real-world head impacts. 11 Another used existing helmet-mounted sensors to evaluate the correlation between different head injury metrics and concussion risk. 13 Balance is often used as a component of clinical evaluation of concussion and recovery, but the most common assessments are visually scored by trained personnel, which introduces human error and variance.…”