A primary source of error for existing head impact measurement systems is their imperfect coupling to the skull. It is easy to observe that helmets slide on the head, skin patches move as the skin stretches and deforms, and mouth guards can move within and outside an athlete’s mouth. There is a general consensus within the concussion research community that an impact sensor that is more rigidly coupled to the bony skull would be able to obtain more accurate in vivo kinematic measurements that could be used both for primary research applications as well as a “gold standard” against which to compare existing impact sensing systems in the field. We propose to develop and validate a novel head impact sensor that will be rigidly coupled to the bony skull by its attachment to the upper teeth. This innovative concept will more tightly couple sensor and skull motion, which is anticipated to improve the accuracy of head kinematics measurements. The study team is uniquely positioned to perform this project. We possess the technical expertise in engineering and orthodontics, as well as the clinical and research experience in concussion biomechanics necessary to develop the proposed sensor, perform initial laboratory validation testing, and ultimately to study this technology in a field setting. In this pilot proposal, we will pursue the following aims:
- To develop a working prototype head impact sensor that can be rigidly affixed to the upper teeth. The sensor will be capable of detecting head accelerations exceeding a programmable threshold and measuring the head’s linear and angular kinematic profiles with six degrees of freedom.
- To perform initial validation of the prototype head impact sensor’s measurements against a reference sensor affixed intracranially at the center-of-mass of a human cadaver head during laboratory-based free drop tests. The prototype impact sensor measurements will be compared in 3 dimensions to those of the intracranial reference sensor at the center-of-mass of the cadaver head. Secondary analyses will be carried out comparing the prototype impact sensor measurements to those taken by a HITS-equipped football helmet and an X-Patch affixed to the cadaver head, also in three dimensions.