Patent ID: 7071682

Claim:
A method for determining movement of a movable target with respect to a fixed initial location, comprising the steps of: designating the fixed initial location; providing the moveable target movable with respect to the initial location, wherein the movable target has a plurality of individually identifiable magnetic irregularities, and wherein the moveable target has a target origin; providing a stationary magnetosensitive array proximally located with respect to the moveable target such that the array senses the magnetic irregularities of the moveable target, the array having an array origin located at a predetermined fixed distance, L 0 , from the fixed initial location; identifying a magnetic irregularity of the moveable target; determining a first distance, Y, equal to a distance of the identified magnetic irregularity to the target origin; determining a position of the identified magnetic irregularity with respect to the array, wherein a second distance, X, is determined which is equal to a distance of the identified magnetic irregularity to the array origin; and determining a target origin distance, L, of the target origin with respect to the fixed initial location, according to a relation: L=L 0 +X−Y.