Description  Claims  Drawing  Cited references 

US20130229238A   [0012] 
US8390362B   [0013] 
US7705685B   [0014] 
US5982201A   [0015] 
US4591807A   [0016] 
US2006091875A   [0018] 
US2009051342A   [0019] 
US4890052A   [0020] 
US2010181985A   [0021]