Citation

Cooper GJ, Pearce BP, Cater SR, Kenward CE, Townend D. Proc. IRCOBI 1989; 17: 123-138.

Copyright

(Copyright © 1989, International Research Council on Biomechanics of Injury)

DOI

unavailable

PMID

unavailable

Abstract

Materials have been applied to the thoracic wall of anesthetized experimental animals exposed to blast overpressure to investigate the coupling of direct stress waves into the thorax and the relative contribution of compressive stress waves and gross thoracic compression to lung injury. The ultimate purpose of the work is to develop effective personal protection to servicemen exposed to blast overpressure. Foam materials acted as acoustic couplers and resulted in a significant augmentation of the visceral injury; decoupling and elimination of injury may be achieved by application of a high acoustic impedance layer on top of the foam. In vitro experiments studying stress wave transmission through the various layers showed a significant increase in power transmitted by the foams, the amplification occurred principally at high frequencies. Material such as copper placed upon the foam achieved substantial decoupling at high frequencies - low frequency transmission was largely unaffected. The studies suggest that direct transmission of stress waves, and not gross thoracic compressions account for lung parenchymal injury with blast loading. Conventional impacts producing high body wall velocities will also lead to stress wave generation and transmission - if the body wall distortion is not severe, stress wave effects may dominate the visceral response to the impact with direct compression and shear contributing little to the aetiology of the injury.