A conformal microwave antenna applicator for circumferential ablation

This paper presents a circumferential tissue ablation device used to form a circumferential conduction block in a pulmonary vein. The circumferential ablation element includes an expandable balloon that is adapted to conform to the pulmonary vein (PV) in the region of its ostium; a microwave transducer is provided and conformed to the balloon's skin, which can form the circumferential ablation by transmitting microwave energy. The microwave transducer includes a mechanism of impedance tuning by which the microwave ablation catheter system can match the impedance of its power supply with the transmission line to minimize reflected power and optimize energy delivery to targeted tissues.