Abstract: A medical device system includes a needle having a tip including a permanent magnet, and a magnet sensing device including a plurality of sensors configured to detect the magnetic field of the permanent magnet. The magnet sensing device is operable to localize a position of the permanent magnet relative to the magnet sensing device and to indicate a path of the needle on a display.

Abstract: Methods of locating a tip of a central venous catheter (“CVC”) relative to the superior vena cava, sino-atrial node, right atrium, and/or right ventricle using electrocardiogram data. The CVC includes at least one electrode. In particular embodiments, the CVC includes two or three pairs of electrodes. Further, depending upon the embodiment implemented, one or more electrodes may be attached to the patient's skin. The voltage across the electrodes is used to generate a P wave. A reference deflection value is determined for the P wave detected when the tip is within the proximal superior vena cava. Then, the tip is advanced and a new deflection value determined. A ratio of the new and reference deflection values is used to determine a tip location. The ratio may be used to instruct a user to advance or withdraw the tip.