Reinforced catheter tip via roller extrusion
With smaller gauge catheters, forming distal tip structures, termed “tipping,” can be increasingly challenging. The thin wall-thicknesses of these small gauge catheters provide a reduced cross-sectional surface area with which to couple the distal tip structure to. This increases the risk of failure of the device either during manufacture or during use. To address the foregoing, embodiments include forming and placing a spiral plug within a lumen of a proximal section of the catheter. The spiral plug co-operates with the catheter to provide an increased wall thickness and an increased cross-sectional surface area with which to couple a distal tip structure thereto. Further the spiral plug can align the lumen of the catheter body with a lumen of the distal tip structure. The spiral plug can be sacrificial and provide increased material across the joint, mitigating joint failure.
1 . A method of forming a catheter, comprising:
extruding a proximal section of a catheter body having a first catheter lumen and a second catheter lumen; and
coupling a distal tip structure to the proximal section, comprising:
placing a spiral plug in a rolled configuration within the first catheter lumen;
placing a plug within the second catheter lumen, a distal tip of the plug aligned with a distal end of the second catheter lumen;
aligning a lumen of the distal tip structure with the first catheter lumen; and
coupling a proximal end of the distal tip structure with the distal end of the proximal section.
2 . The method according to claim 1 , further including forming the spiral plug, comprising:
providing a tube having an outer diameter equal to or greater than an inner diameter of the first catheter lumen;
cutting the tube longitudinally; and
rolling the tube into a spiral configuration, having an outer diameter equal to or less than the inner diameter of the first catheter lumen.
3 . The method according to claim 1 , wherein the spiral plug engages the first catheter lumen in an interference fit.
4 . The method according to claim 1 , wherein coupling the proximal end of the distal tip structure with the distal end of the proximal section includes adhering, bonding, or welding the distal tip structure with the proximal section.
5 . The method according to claim 1 , wherein coupling the proximal end of the distal tip structure with the distal end of the proximal section includes adhering, bonding, or welding the spiral plug to an inner surface of the first catheter lumen and to one or both of the distal tip structure and the proximal section.
6 . The method according to claim 1 , further including boring out a portion of the first catheter lumen adjacent the spiral plug.
7 . The method according to claim 1 , wherein the distal tip structure is formed of a first material, the proximal section is formed of a second material, and the spiral plug is formed of a third material, the second material being different from one or both of the first material and the third material.
8 . The method according to claim 7 , wherein the second material includes a more compliant, or softer durometer, mechanical properties relative to the first material.
9 . The method according to claim 1 , wherein the distal tip structure includes one or both of a first section and a transition section.
10 . The method according to claim 9 , wherein the first section defines a single lumen and defines an outer diameter that is less than an outer diameter of the proximal section.
11 . The method according to claim 10 , wherein the transition section defines a tapered outer profile extending from the outer diameter of the first section to the outer diameter of the proximal section.