A catheter system includes a positioning catheter for receiving an injection needle into its lumen. Structurally, the injection needle incorporates a plurality of loops that are mounted directly onto its shaft. As the injection needle is moved in a distal direction to exit from the lumen of the catheter, the loops are individually biased to transition from a folded configuration, and into a deployed configuration. In their deployed configurations, the loops create a barrier that is oriented perpendicular to the needle. Thus, the barrier acts to limit the depth of insertion of the needle into target tissue of a patient, to a predetermined depth, and to prevent perforation of the target tissue by the catheter tip.
