Apparatus and methods are provided for accessing body lumens and/or for delivering instruments into body lumens, e.g., vessels within a patient's vasculature. A flexible sheath is provided that is expandable from a contracted condition to an enlarged condition wherein the sheath at least partially defines...http://www.google.com/patents/US20030233115?utm_source=gb-gplus-sharePatent US20030233115 - Expandable guide sheath and apparatus and methods using such sheaths
