Interventional instrument comprising an ultrasound transducer

An interventional instrument comprising an ultrasound unit and a rotation unit for rotating the ultrasound unit, wherein the rotation unit comprises an actuation element being:

• an electroactive polymer for actuating the rotation of the ultrasound unit, wherein the ultrasound unit is arranged within a housing of the interventional instrument, wherein the rotation unit comprises a support means on which the ultrasound unit is rotatably supported, wherein the support means and the housing form a first space and a second space, wherein the rotation unit comprises a pump with the electroactive polymer, wherein the pump is adapted to pump a filling material from the first space to the second space, wherein the housing, the support means and the ultrasound unit are arranged such that the ultrasound unit is rotated, if the filling material is pumped from the first space to the second space, or
• a one-way shape memory alloy for actuating the rotation of the ultrasound unit, wherein the one-way shape memory alloy is formed as a coil which is configured to provide a rotating force for rotating the ultrasound unit from an initial position to a rotated position, wherein the rotation unit comprises a force providing element for providing a force for forcing the ultrasound unit back from the rotated position to the initial position.