SAFETY CATHETER PLACEMENT ASSEMBLY AND METHOD

Safe placement of a flexible catheter is enabled by (a) novel positive connection of the separable parts and (b) by unique indicating means. A syringe has a functionally integral needle and provides a convenient handle to which the catheter sheathing the needle is releaseably attached by a smoothly operating twist lock against inadvertent separation during venipuncture and catheter placement manipulation. After venipuncture catheter placement free from danger of damaging a blood vessel lumen wall is effected by advancement of the catheter tip into sheathed relation to the leading end of the needle serving as a stiffener to facilitate advance of the catheter within the lumen. Cooperating means respective associated with the catheter and with the needle and remaining exposed after the catheter and sheathed needle have entered the lumen provide indication of the relative longitudinal position of the catheter end and needle tip, and may also helpfully indicate whether the catheter and needle are safely interconnected against unintentional longitudinal displacement as well as a condition of relative freedom for separation when it is desired to withdraw the needle from the catheter.