Patent ID: 9002437
Filing Date: 2015-04-07
Classification: A61B,A61N

Abstract:
1. A method, comprising: in a medical navigation system: driving a transmitter at a first frequency and at least a second frequency to generate a first and at least a second electromagnetic field, wherein the first and second frequencies are sufficiently low such that the first and second electromagnetic fields are frequency independent; receiving a first and at least a second distorted field corresponding to the first and second electromagnetic fields, respectively, with each of at least two electromagnetic (EM) sensors attached to a surgical device; generating a first and at least a second signal in response to receiving the first and second distorted fields, respectively, using each of the at least two EM sensors; and determining a distortion in the first and at least the second signals based at least on a distance between the at least two EM sensors and a difference between the first and second signals generated by each of the at least two EM sensors.