ULTRASONIC INSTRUMENT

摘要

An ultrasonic invasive instrument such as a biopsy needle has an ultrasonic transducer (12) mounted at one end. The transducer is electrically coupled to two conductors, such as a stylet (10) and cannula (11), to transmit signals indicating its position in an ultrasonic field transmitted by an imaging scanner. The transducer (12) is coupled to at least one of the conductors (10, 11) by an ohmic or capacitive coupling. In particular, body fluids can provide an electrical coupling between the transducer (12) and the cannula (11).