| 摘要 |
Apparatus for determining the position of an object within a body of a subject includes at least one acoustic wave generator, adapted to direct acoustic waves toward the body. A transducer (70) is adapted to be fixed to the object and constructed to emit electromagnetic radiation responsive to the acoustic waves with a response that varies depending on an orientation angle of the transducer relative to the at least one acoustic wave generator. One or more detectors are adapted to detect the electromagnetic radiation and to generate signals responsive thereto. A signal processor is coupled to process the signals so as to determine an angular orientation coordinate of the object in the body. |
