Patent ID: 8734466

Claim:
A system for controlled insertion and withdrawal of at least one electrode in an anatomy comprising: at least one insertion cannula that defines a first through passage and a distal end; a macroelectrode moveably disposed in the first through passage, the macroelectrode having a proximal end and a distal end, the distal end selectively extendable to a first extended position outside and beyond the distal end of the at least one insertion cannula to engage the anatomy, the distal end also selectively extendable to a second extended position outside and beyond the distal end of the at least one insertion cannula, the distal end of the macroelectrode being extended further away from the distal end of the at least one insertion cannula in the first extended position as compared to the second extended position, the macroelectrode defining a second through passage; an insulating member that covers a portion of the macroelectrode and that electrically insulates the macroelectrode from the at least one insertion cannula; a microelectrode moveably disposed in the second through passage, the microelectrode having a proximal end and a distal end, the distal end selectively extendable beyond the distal end of the macroelectrode to engage the anatomy; and an indicator having a visible marking on the insulating member, the visible marking being a color contrasted from other portions of the insulating member, the visible marking having a length that is substantially equal to a difference in distance between the first extended position and the second extended position, the visible marking being fully blocked by the at least one insertion cannula when the macroelectrode is in the first extended position and the visible marking being fully revealed from the at least one insertion cannula and fully visible when the macroelectrode is in the second extended position such that the indicator indicates only that the macroelectrode is in the first extended position or alternatively in the second extended position.