Abstract: Certain aspects of the present disclosure provide methods and apparatus for measuring an injection catheter needle insertion depth and/or injection solution efficacy. An example injection catheter may include a catheter tube and a retractable, electrically conductive needle disposed in the catheter tube and configured to extend from the catheter tube. The injection catheter may also include one or more electrodes disposed at a distal portion of the catheter tube, an electrical lead coupled to the needle, and electrical leads coupled to the electrode(s). An example method includes deploying such an injection catheter adjacent to the tissue, extending a needle into the tissue, receiving electrical signals from an electrical lead coupled to the needle and from other electrical leads coupled to the electrode(s), determining a bioelectrical parameter based on the received electrical signals, and determining a depth of the needle inserted into the tissue based on the bioelectrical parameter.

Abstract: The needle injection catheter includes a delivery tube and at least one hypotube that fits slidably within the delivery tube. The hypotube has at least three hollow needle portions extending outwardly at its distal end. The needle portions curve outwardly and have ends shaped to penetrate tissue. At least one reference electrode is located on the delivery tube, spaced from the second end. At least one proximal electrode is located adjacent and spaced from the end of the needle portion. The proximal electrode is electrically connected to a first notification device. A microcircuit is electrically connected to the proximal electrode, the reference electrode and to a power supply. A distal electrode is located adjacent the end of the needle portion and electrically connected to the microcircuit. A tip electrode is located adjacent the second end of the delivery tube and electrically connected to a second notification device and the microcircuit.