Acoustic imaging balloon catheters formed by a disposable liquid-confining sheath supporting a high fidelity, flexible drive shaft which carries on its end an ultrasound transducer and includes an inflatable dilatation balloon. The shaft and transducer rotate with sufficient speed and fidelity to produce...http://www.google.es/patents/US5421338?utm_source=gb-gplus-sharePatente US5421338 - Acoustic imaging catheter and the like
