#$%^&*AU2016259376A120170706.pdf#####ABSTRACT Catheterization is carried out by inserting a sheath into a human patient and 5 moving a catheter having an electrode through the sheath lumen. A variation between a first threshold value and a second threshold value in electrical current through the electrode is identified. Responsively to the variation, it is reported that a portion of the catheter has transitioned between an in-sheath condition and an out-of-sheath condition. The sheath is defined and identified by the historical tO data of the readings of the magnetic sensor during its movements.7/7 120 SET THRESHOLD VALUES 122 ADVANCE CATHETER DISTA NO ELECTRODE CURRENT >;UPPER THRESHOLD YES RETRACT CATHETER 126 YES PROXIMAL YES ELECTRODE CURRENT >; LOWER THRESHOLD? NO E D 130 FIG. 14