An improved ablation catheter system comprising an ablation element on a distal section of an elongate catheter tubing, the ablation element having dual capability of radiofrequency ablation and ultrasound ablation, the ablation element comprising an ultrasound transducer, a conductive outer surface...http://www.google.de/patents/US6235024?utm_source=gb-gplus-sharePatent US6235024 - Catheters system having dual ablation capability
