The present disclosure relates to a sheath system for enabling access through an opening in the body of a patient is provided. The sheath system includes a dilation assembly having a radially expandable tubular sheath defining a lumen having a first cross-sectional area when in a non-expanded condition,...http://www.google.ca/patents/US7896897?utm_source=gb-gplus-sharePatent US7896897 - Sheath introduction apparatus and method
