Mesostructure Based Scatterers in Helmet Supension Pads

Abstract

A method of mitigating an incoming pressure wave comprising creating through-holes or channels in a soft foam layer, creating through-holes or channels in a hard foam layer, placing the hard foam layer inside a helmet shell, and placing the soft foam layer on the hard foam layer.

What we claim is: 
     
         1 . A method of mitigating an incoming pressure wave comprising:
 creating through-holes in a soft foam layer;   creating through-holes in a hard foam layer;   placing the hard foam layer inside a helmet shell; and   placing the soft foam layer on the hard foam layer;
 wherein the holes or channels in the soft foam layer and the hard foam layer form a row of holes or channels that is parallel or nearly parallel to the interface between the soft foam layer and the hard foam layer. 
   
     
     
         2 . The method of  claim 1  wherein the holes have a diameter of about 2.35 mm and a center to center distance in each row of about 12.7 mm. 
     
     
         3 . The method of  claim 1  further including creating a row of holes along the interface between the soft foam layer and the hard foam layer. 
     
     
         4 . The method of  claim 3  wherein the holes have a diameter of about 1.86 mm and further including the step of reducing an incoming pressure wave of about 47000 Pa to about 94% of the pressure. 
     
     
         5 . An apparatus for mitigating pressure into the brain from an incoming pressure wave comprising:
 a helmet shell;   a hard foam layer;   a soft foam layer;   wherein the hard foam layer is between the helmet shell and the soft foam layer and wherein the interface between the hard foam layer and the soft foam layer comprise a row of holes with a hole diameter of about 6.35 mm and a center to center distance of about 12.7 mm and wherein at an average peak pressure of about 84000 Pa for an incoming pressure wave reaching the helmet shell and propagating through the hard foam layer and the soft foam layer is reduced by about 44%.   
     
     
         6 . The apparatus of  claim 5  further including two more rows of holes wherein a first row of holes is in the hard foam layer along the length of the hard foam layer and a second row of holes is in the soft foam layer along the length of the soft foam layer and wherein the hole diameter is about 1.86 mm and the center to center distance in each row is about 12.7 mm. 
     
     
         7 . The apparatus of  claim 6  wherein an incoming pressure wave of about 47000 Pa propagating through the helmet shell through the hard foam layer and through the soft foam layer is reduced by about 94%.