Accession Number : ADA612600


Title :   Mechanisms and Mitigation of Hearing Loss from Blast Injury


Descriptive Note : Annual rept. 1 Oct 2012-30 Sep 2013


Corporate Author : COCHLEAR BOULDER LLC CO


Personal Author(s) : Easter, James R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a612600.pdf


Report Date : Oct 2013


Pagination or Media Count : 21


Abstract : This phase of a multi-year project continues and expands studies aimed at an improved biomechanical understanding of blast injury and development of new technologies for the mitigation of auditory injury from blast. Off-the-shelf fiber optic pressure sensors were used to measure and correlate external auditory canal (EAC) and intracranial pressure profiles in a cadaver head during blast generated by a shock tube. These wave forms were recorded and reproduced through a programmable bench top blast simulator system. This system, developed in Year 1, was improved through use of a folded horn approximating an exponential reduction in cross-section. The improved system delivers simulated blast wave forms with peak pressures exceeding 180dBSPL to human temporal bone specimens. Intracochlear pressures were measured using during harmonic and impulse stimuli using off-the-shelf fiber optic pressure probes with polyimides heating to resist damage from extreme pressures. Ossicular and round window membrane displacements were recorded simultaneously using a scanning LDV. These results give system compliance and group delay for the propagating blast wave, and the rate of energy transfer to the cochlea. Those parameters will be used to improve auditory hazard models and develop active systems protective against blast injury.


Descriptors :   *HEARING , *PRESSURE , *WOUNDS AND INJURIES , BIOMECHANICS , BLAST , BLAST WAVES , DAMAGE , EAR PROTECTORS , FIBER OPTICS , POLYIMIDE RESINS , SHOCK TUBES , SIMULATION , TRAUMA , VELOCITY


Subject Categories : Anatomy and Physiology
      Medicine and Medical Research
      Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE