Friction-free conduit

A catheter (700) may include a tubular member (702) having a lumen and an outer surface; a sleeve (704) configured to be positioned in the lumen in a retracted configuration and to be everted onto at least a portion of the outer surface in an everted configuration; and a filament body (700) configured to retract the sleeve (702) to the retracted configuration. The catheter may include a distal proximal through-hole (774), wherein a filament (770) extends from the lumen through the through-hole (774). The pulling member (772) may be located on the distal end of the wire body (770). The filaments (770) may be looped, rolled, and/or bundled in the catheter (700) when the sleeve (704) is in the retracted configuration. A shuttle (718) is attachable to a distal end of the cannula (704), where the shuttle (718) includes a tubular member configured to keep the cannula (704) unobstructed, and a filament (770) engages the shuttle (718) to retract the cannula (704) into the lumen. 本发明涉及一种导管(700)，该导管可包括：管状构件(702)，其具有管腔和