Patent ID: 7558616

Claim:
Apparatus for locating a tissue within a body of a subject, comprising: a wireless acoustic tag configured to be fixed to the tissue and adapted, responsive to acoustic waves incident thereon, to return acoustic echoes; a plurality of acoustic transducers, which are adapted to be placed at respective positions so as to direct the acoustic waves into the body toward the tissue and to receive the acoustic echoes returned from the tag responsive to the acoustic waves, the transducers being further adapted to generate first signals responsive to the received echoes; a plurality of transducer position sensors, coupled respectively to the acoustic transducers so as to generate second signals indicative of the respective location and orientation coordinates of the acoustic transducers in an external frame of reference; and a processing unit, coupled to process the first signals and the second signals so as to determine the location and orientation coordinates of the acoustic tag in the external frame of reference.