A catheter enables measuring and approximating its distal end position within the body to facilitate catheter insertion and improve accuracy and control. By wrapping a long infusion catheter with an outer coating, the catheter can be guided into a vein or vessel by pulling on the outer coating and forcing its separation in a Y-shaped separation housing anchored close to the insertion point. Since there is no need for a guidewire or stylet and the outer coating acts as a sterile peel package, the catheter can be placed while infusing and maintain its own closed sterile environment during insertion.