However, {HEAD ~ any biocompatible material} that can be readily compressed and that provides {TAIL ~ a moderate back force} when somewhat compressed, such as elastomers including silicones and polyurethanes and fabrics including those made with polyterefluoroethylene may be used to form fabric tube 50 
However , { HEAD ~ any biocompatible material } that can be readily compressed and that provides { TAIL ~ a moderate back force } when somewhat compressed , such as elastomers including silicones and polyurethanes and fabrics including those made with polyterefluoroethylene may be used to form fabric tube 50
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH