Abstract: Methods of forming catheters are disclosed, together with methods of forming split tip catheters. In one aspect of the invention, the manufacturing methods can include the steps of: providing first and second catheter tubes each having a substantially D-shaped cross-section, and attaching at least a portion of longitudinal lengths of the first and second catheter tubes along flat surfaces of the first and second catheter tubes to form a dual lumen catheter assembly. The tubes can be fused along at least about 10%, preferably along at least about 50%, more preferably in some applications along at least about 70%, 80% or 90% of the longitudinal length.

Abstract: Methods of forming catheters are disclosed, together with methods of forming fixed tip catheters. In one aspect of the invention, the manufacturing methods can include the steps of: providing first and second catheter tubes, a distal end of the first catheter tube extending a longitudinal length beyond a distal end of the second catheter tube, and attaching a flow diverting structure to an outside surface of the first catheter tube between the distal ends of the first and second catheter tubes. The flow diverting structure can be oriented on the first catheter tube to divert fluid flowing through an inner lumen of the second catheter tube.

Abstract: Asymmetric lumen catheter devices are disclosed. In one aspect of the invention, a catheter assembly includes a first catheter tube having a first lumen extending longitudinally through the first catheter tube and a second catheter tube attached to the first catheter tube. The second catheter tube extends a longitudinal length beyond a distal end of the first catheter tube and has a second lumen extending longitudinally therethrough. The first lumen has a larger cross-sectional size than the second lumen.

Abstract: Multi-lumen catheter devices having at least one split-tipped end are disclosed, together with methods of forming such split tip catheters. In one aspect of the invention, the manufacturing methods can include the steps of: providing a catheter body having at least a first and a second internal lumen extending longitudinally through the catheter body; removing a distal portion of the catheter body to form a first distal tip segment such that the first lumen extends longitudinally within this tip segment beyond the second lumen; and joining a second lumen tip segment to the catheter body in communication with the second lumen. The second tip segment can be joined to the catheter body such that it is at least partially separated from the first tip segment and, in some embodiments, preferably diverges at an angle relative to the first tip segment.

Abstract: Methods and apparatus are disclosed for inserting flexible, multi-lumen catheters into blood vessels, and in particular, for inserting flexible, split-tip catheters into blood vessels. The invention accomplishes these objects by temporarily stiffening each catheter lumen and tip independently through use of intra-catheter stiffener elements disposed within the catheter lumens. This provides means for advancing the catheter/stiffeners assembly through a subcutaneous tunnel, and over a plurality of guidewires until a distal tip of the catheter is at a desired position within the vessel. The intra-catheter stiffener elements are sufficiently stiffening to allow advancing the catheter over guidewires, but sufficiently flexible to allow bending and looping of the catheter for proper placement within the vessel.

Abstract: Methods and apparatus are disclosed for inserting flexible, multi-lumen catheters into blood vessels, and in particular, for inserting flexible, split-tip catheters into blood vessels. The invention accomplishes these objects by temporarily stiffening each catheter lumen and tip independently through use of intra-catheter stiffener elements disposed within the catheter lumens. This provides means for advancing the catheter/stiffeners assembly through a subcutaneous tunnel, and over a plurality of guidewires until a distal tip of the catheter is at a desired position within the vessel. The intra-catheter stiffener elements are sufficiently stiffening to allow advancing the catheter over guidewires, but sufficiently flexible to allow bending and looping of the catheter for proper placement within the vessel.