Patent ID: 8348892

Claim:
A method of instrumenting a body lumen or cavity comprising the steps of: inserting a sheath with a pre-inserted dilator, and advancing the sheath to a treatment or diagnostic site within the body lumen or cavity, wherein the sheath comprises a distal region which is collapsed in diameter, the sheath further comprising distorted proximal and distal chevrons, dilating the distal region of the sheath so that the distal region of the sheath is expanded, wherein the proximal and distal chevrons become undistorted such that a full-size lumen exists within the sheath and extending from the proximal end to the distal end, collapsing the dilator by an action applied at the proximal end of said dilator, removing the dilator from the sheath, inserting instrumentation through the lumen of the sheath, performing therapy or diagnosis with the instrumentation, and removing the sheath from the patient.