| Popis: |
Head and spine injuries, such as traumatic brain injury, skull fracture,concussion and osteoligamentous cervical spine injury continue to beprevalent in motor vehicle crashes, athletics and the military. Automotivesafety systems, athletic safety equipment and military personal protectiveparaphernalia designs have generally focused on protection discretelydesigned on a component basis – head or spine – but not a systems basis,considering the head-spine linkage simultaneously. But since the cervicalspine acts as the attachment point for the head, the boundary conditionsapplied to the cervical spine influence the behavior of the head. Hence, inanalyzing injury risk for the head and the spine, each structure composesone portion of an intrinsically linked osteoligamentous system; thus injuryrisk for the head and the cervical spine might be more appropriatelyconsidered concurrently as opposed to individually.Historically, component-based injury protection designs have utilizedhead and cervical spine injury risk criteria developed from human, animaland anthropomorphic surrogate studies. While a plethora of these priorstudies separately analyzed head injury risk via linear acceleration, HeadInjury Criterion (HIC) or Gadd Severity Index (GSI), or cervical spine injury risk via axial/shear forces, bending moments or the Neck Injury Criterion(Nij), relatively few of these studies employed a systems-based approach tounderstand coupled head-cervical spine injury risk behavior.Thus, designing for optimal head and cervical spine injury protectionmay not be as trivial as separate consideration of head or spine componentinjury thresholds. Therefore, through a series of six biomechanicalengineering studies that comprised the chapters of this dissertation, the workpresented here broadly investigated head and cervical spine injury protectionon a systems-based approach considering head and cervical spine injury risksimultaneously. In Chapter 1, injury risk in inertial loading during real-worldlow energy minor rear car crashes was analyzed. In Chapter 2, these minorcrashes from Chapter 1 were further investigated via use of numericalsimulation in MADYMO. While Chapters 1 and 2 explored low energy carcrash loading, Chapter 3 explored multivariate head and cervical spine injuryimplications from direct head loading during frontal airbag inflation in highenergy experimental car crashes. Chapter 4 expanded the direct frontalhead impact loading analyzed in Chapter 3 to include oblique and lateralimpact loading during impact experiments with a Hybrid III anthropomorphictest device. The low- and high-energy injury analysis methods developed inChapters 1 through 4 helped drive the study of multivariate injury risk inresponse to experimental omnidirectional athletic head impacts in Chapter 5.Chapter 6 further built on the high-energy athletic impacts from Chapter 5via Matlab and Simulink simulation of helmeted impacts using a systemsdynamics approach. Finally, Chapter 7 analyzed development of an impact pendulum, pilot cadaveric injury response to direct head impact and analysisof similar impacts in a helmeted human surrogate. The results of all of theserelated studies indicated that head and cervical spine injury risk wereinterrelated during direct or inertial car crash and athletic impacts. |
