GUIDELINES FOR DEVELOPING A COMPLEX HUMAN INJURY PREDICTION MODEL

INTRODUCTION: Typically, life support equipment is developed using manikin response and injury criteria derived from non-aerospace environments. Human injury mechanisms resulting from relevant dynamic loading are uncertain. To address these deficiencies, a team was assembled with expertise in post mortem human specimen (PMHS) experimentation, probabilistic modeling, and military human systems. METHODS: Due to the complexity involved in creating the NAVAIR head, brain, and spine injury risk prediction model (HBSM), a new program management approach was required. The classic method of conducting a series of experiments and then fitting the data to a model would not suffice. Clear requirements were outlined to define occupational injuries of interest, pertinent military population, knowledge gaps, and a roadmap was developed to produce a validated design tool within project cost and schedule. Once a modeling approach was chosen (probabilistic finite element), modeling requirements determined the types of experimentation and data needed. A modeling shell was created based on limited existing knowledge and specific animal and PMHS studies were conducted to define material properties and injury mechanisms. Studies were timed so that new data were available when the modellers were ready to incorporate it. This involved close coordination and active collaboration from different institutions, which otherwise could be in competition for funding. Geographically diverse sites were chosen to ensure the availability of suitable PMHS. An ftp site facilitated data sharing and post monthly updates. Developing this relationship required mutual respect, open communications, productive interaction amongst team members, and a single source for program decisions. RESULTS: HBSM has been exercised and for quality assurance, program outputs were presented at scientific fora (N=57) and published in referred journals (N=22). DISCUSSION: The process outlined led to the development of a quantitatively validated probabilistic HBSM and a hazard assessment tool. NAVAIR will employ this in future development of life support and performance enhancement equipment.