Patent ID: 8204586

Claim:
A method of evaluating a tissue location in a subject, the method comprising: (a) generating a substantially linear field gradient in the subject across the tissue location by broadcasting from a plurality of broadcasting electrodes coupled to a signal generator a respective number of multi-frequency signals, wherein each one of the multi-frequency signals is a summation of signals with different frequencies and wherein the signals with the different frequencies in the each one of the multi-frequency signals are assigned with corresponding amplitudes to form the substantially linear field gradient; (b) obtaining a linear field gradient dependent reading from a sensing element, wherein the sensing element is configured to physically attach to the tissue location with an attachment element such that movement of the sensing element coincides with movement of the tissue location and wherein the linear field gradient dependent reading is associated with a location of the sensing element in the substantially linear field gradient; and (c) evaluating the tissue location based on the linear field gradient dependent reading.