Abstract: Apparatus and methods for providing controlled pressure-flow pulses which purge a catheter system with turbulent flow flushing. Accomplishment of such controlled pressure-flow pulses is provided by a variety of inventive devices including a special plunger rod for a conventional syringe, other interactive parts for conventional syringes, an in-line catheter attachable device which automatically generates the controlled pressure-flow pulses and also single pulse, digitally operated devices.

Abstract: A safety, over-the-needle midline catheter, designed generally for insertion distal to the antecubital crease to be threaded proximally to a site just distal to the axilla. An accompanying safety apparatus is employed which permits only proximal displacement of an associated needle cannula into a safety housing. The catheter has an internal lumen of constant diameter and a proximally disposed taper which in conjunction with the constant internal diameter, provides a wall thickness which effectively resists kinking and associated closure of said lumen which might result from bending of an elbow when a portion of the catheter is disposed at the cubital crease. A butterfly is disclosed which has a collet having a superiorly disposed slit and lips associated with the slit which are sufficiently thin and supple to permit the catheter to be separated from the collet (and butterfly) while wings of the butterfly are disposed upon skin of a patient.