Patent ID: 8109877

Claim:
A method for determining a position and a change in the position of an anatomical structure using a surgical navigation system, the method comprising the steps of: providing a surgical navigation system; attaching a substrate in a removable manner to an outer surface of a body, the substrate having an associated sensor and having a positional device for determining a position of the anatomical structure relative to the sensor, wherein the positional device includes an ultrasonic imaging device attached to the substrate, and wherein the body includes an anatomical structure spaced interiorly from the outer surface; determining a position of the anatomical structure relative to the sensor using the ultrasonic imaging device; tracking the sensor with the surgical navigation system to determine a position of the sensor; determining the global position of the anatomical structure by concatenating the position of the sensor and the position of the anatomical structure relative to the sensor; and displaying the position of the anatomical structure on a display unit, wherein the positional device further includes a point source disposed adjacent the anatomical structure, and wherein the ultrasonic imaging device and the point source are utilized to determine a position of the anatomical structure relative to the sensor, wherein the ultrasonic imaging device comprises a plurality of receivers and the point source comprises a plurality of source transducers, and further comprising the step of determining a position of each source transducer by activating one source transducer at a time to emit an ultrasonic beam and receiving each ultrasonic beam by the receivers.