A medical device including a catheter body, a first elongate body, and a service loop ring. The catheter body has a catheter shaft. The first elongate body extends through at least part of the catheter shaft and is configured to move longitudinally in the catheter shaft. The first elongate body is looped through the service loop ring to form a service loop configured to expand and contract as the first elongate body moves longitudinally in the catheter shaft.

Described herein are devices and methods for guide catheters having one or more regions of increased flexibility. A flexibility region comprises one tubular segment of the guide catheter with a non-linear seam between two non-concentric layers of material having different durometers. A non-linear seam, such as a zig-zag or sinusoidal configuration, permits controlled compression of lower durometer material between portions of higher durometer material.

A catheter with a variable circular loop responsive to a contraction wire for coiling is supported by a member having a tapered distal section that transitions from a circular cross-section to a generally rectangular cross-section while maintaining a uniform cross-sectional area along the entire tapered length for improved coiling characteristics. A radially constrictive sleeve prevents separation of the contraction wire from the support member to minimize misshaping of the loop during contraction.

Devices and techniques that enable multiple electrodes to be positioned proximate organic tissue, such as human tissue. In one embodiment, a catheter is provided that includes a shaft and a distal segment. The distal segment includes a plurality of electrodes configured in a plane that is substantially parallel with the longitudinal axis of the shaft.

A catheter may include a tubular member having a lumen and an outer surface, a sleeve configured to be positioned in the lumen in a retracted configuration and to evert over at least a portion of the outer surface in an everted configuration, and a filament configured to retract the sleeve into the retracted configuration. The catheter may include an aperture proximal of a distal end, where the filament extends through the aperture from the lumen. A pull member may be on a distal end of the filament. The filament may be looped, coiled, and/or bunched in the catheter when the sleeve is in the retracted configuration. A shuttle may be attached to a distal end of the sleeve, where the shuttle includes a tubular member configured to maintain patency of the sleeve, and the filament engages the shuttle to retract the sleeve into the lumen.

Methods and devices described for improved catheters including those having a deflectable section to allow for expansion while maintaining flow through a vessel.

A steerable catheter having a hub with a control feature includes a semi-rigid catheter with the hub attached at the proximal end. The distal end of the catheter includes a distal tip and a flexible portion adjacent the distal tip. The catheter includes a working channel, and further includes a channel through which a tension member or wire extends to the distal tip. Tension in the wire causes the distal tip to deflect and be steered. The hub includes a fixed member attached to the catheter, an inner member that moves axially relative to the fixed member, and an outer member that rotates relative to the inner member and the fixed member. Rotation of the outer member results in translation of the inner member, which is attached to the tension member and provides for controlled steering of the distal tip.

A guidewire introducable into a bodily lumen having an obstruction therein is provided. An introducer needle is advanced through tissue and into the bodily lumen. A guidewire is advanced through the introducer and into the lumen. The guidewire is advanced further through the lumen until an atraumatic distal tip of the guidewire encounters an obstruction the distal tip cannot pass in a straight forward manner. The distal tip is pressed against the obstruction such that a flexible segment proximal of the distal tip forms a loop distal of the distal tip. The guidewire is advanced further through the lumen such that the loop of the flexible segment is pushed past the obstruction and the distal tip is pulled distally past the obstruction. A greater diameter guidewire extension can be coupled to the back end of the guidewire, providing function as a larger diameter guidewire.

Methods and devices described for improved catheters including those having a deflectable section to allow for expansion while maintaining flow through a vessel.

A catheter includes a catheter body and a distal tip section that includes an elongated member that extends along a longitudinal axis. An anchor mechanism can be disposed along an outer surface of the elongated member and/or within the elongated member in a first configuration. In a second configuration, the anchor mechanism can be configured to extend radially outward with respect to the longitudinal axis to surround at least a portion of the distal tip section.