Abstract: A method and apparatus for retaining a catheter tip in a fixed position within a blood flow and preventing it from contacting a blood vessel wall. The apparatus includes a tip retainer at the distal end of the catheter that stabilizes the tip of the catheter relative to the blood vessel. The catheter tip is retained within the blood vessel spaced from the wall to ensure that it does not contact the wall of the blood vessel. This reduces damage to the blood vessel caused by chronic movement and contact between the catheter tip and the wall of the blood vessel. In one embodiment, the tip retainer includes a prong that penetrates the wall of the blood vessel, thus preventing the catheter tip from moving longitudinally within the blood vessel. In alternative embodiments, the tip retainer contacts the wall but does not penetrate the wall.

Abstract: An elongated catheter formed with multiple lumens from coextruded or other materials such that the inner surface of the extension members or body portion of the catheter may include a higher durometer than the outer surface of the extension members or body portion of the catheter to reduce septum deflection during normal use, and the likelihood of tearing or sticking of the extension members is reduced and the catheter includes a pair of generally cylindrical lumens and the catheter preferably includes a third lumen which is substantially smaller than the first two lumens and the cross sectional area of the lumens of the catheter are maximized with the septums of the catheter being oriented to maximize the flow of fluids through the catheter.

Abstract: An elongated catheter formed of coextruded materials such that the inner surface of the extension members or body portion of the catheter have a higher durometer than the outer surface of the extension members or body portion of the catheter to reduce septum deflection during normal use, and the likelihood of tearing or sticking of the extension members is reduced.