US Patent 9744344 Devices and methods for catheter placement within a vein

An apparatus includes an introducer defining a lumen and a catheter movably disposed in the lumen. The introducer has a distal end portion configured to operably couple to an indwelling peripheral intravenous line at least partially disposed in a vein. The catheter is configured to be moved between a first position, in which the catheter is proximal to the peripheral intravenous line when the introducer is operably coupled thereto, and a second position, in which a distal surface of the catheter is distal to the introducer and disposed at a predetermined distance from a distal tip of the peripheral intravenous line. The predetermined distance defined between the distal surface of the catheter and the distal tip of the peripheral intravenous line is based at least in part on a venous anatomy associated with the vein.