System and apparatus for detecting catheters relative to introducers

A system comprising:

• a catheter including a plurality of electrodes and a sensor member formed of a magnetically permeable material, wherein the sensor member defines a sensor member axis extending along a sensor member length, wherein the sensor member axis is oriented to form an angle θ relative to a longitudinal axis of the catheter, wherein the angle θ is greater than 0°;
• a sheath including a sensor and a lumen to receive the catheter therethrough, the sensor configured to sense movement of the sensor member relative to the sensor and generate a signal;
• and
• a position detection module including an electronic control unit to determine a co-axial insertion distance of the catheter relative to the sheath based on the signal,
• wherein the sensor has an annular shape defining an aperture to receive the catheter therethrough,
• wherein the plurality of electrodes includes a first ring electrode and a second ring electrode, wherein the sensor member extends under at least a portion of the first ring electrode and the second ring electrode.