Device for introducing flexible catheters

Claim 1

A catheter placement unit comprising a plastic cannula adapted to be placed in a blood vessel having an attachment end portion including a generally conically shaped recess formed therein; a divisible catheter guide piece having a longitudinal bore formed therein and first and second end portions; said first end portion being conically shaped for frictional engagement in the conical recess of said cannula; said second end portion of said guide piece having a groove formed therein and a collet mounted in said groove in frictional engagement with said guide piece whereby said collet and the frictional engagement of said first end portion in said conical recess hold the guide piece together; a generally cylindrically shaped elastic element mounted in the bore of said guide piece; said element and guide piece bore having cooperating means for preventing longitudinal movement of said element in said bore, said cooperating means comprising a cooperating recess and flange; said elastic element having an internal bore formed therein and a tapered top portion tapering towards said cannula; and a catheter extending through the bore in said element and said cannula; said catheter having an outside diameter substantially equal to the inside diameter of said bore in the elastic element whereby the catheter can be moved through said element into the cannula with low frictional resistance but movement thereof out of the cannula will be resisted by inward collapse of the tapered top of the elastic element upon outward movement of the catheter and wherein said elastic element has a longitudinally extending slit formed therein to permit removal thereof from said catheter after placement of the catheter.