A distal member including ablation elements to perform ablation of biological member an elongated catheter body, in the target region of the catheter outside the main body and is disposed adjacent the distal end, an ablation catheter for performing audio-monitoring, acoustic beam (6 I transducers include one or more are each configured to receive the reflected echo from it and directed towards the target ablation zone of each and (5), a). Includes a transducer housing that is disposed within (5a, 5b) is an acoustic transducer, the distal member, the distal member, the transducer housing, at least one transducer which is the only part of which can pass through acoustic beam includes a window, at least, are made in (5c) material containing carbon 50%, the material of the transducer window (5c), the transducer window portion of the one, of the acoustic transducer at least in a volume at least the distal member I have an acoustic impedance between the acoustic impedance of the biological element and the acoustic impedance.音響モニタリングも行うアブレーションカテーテルが、細長いカテーテル本体と、遠位端部に隣接して配置されかつカテーテル本体外部の標的領域において生物部材のアブレーションを行うアブレーション要素を含む遠位部材と、音響ビーム(6)を、それぞれの標的アブレーション領域の方へ向けかつそこから反射エコーを受け取るように各々構成された1つ以上の音響変換器(5)とを含む。遠位部材は、音響変換器(5a、5b)が内部に配置される変換器ハウジングを含み、変換器ハウジングは、遠位部材において、音響ビームが通過できる唯一の部分である少なくとも1つの変換器窓を含み、少なくとも、遠位部材の少なくとも1つの変換器窓部分が、体積で少なくとも50%の炭素を含む材料(5c)で作製され、変換器窓の材料(5c)は、音響変換器の音響インピーダンスと生物部材の音響インピーダンスとの間の音響インピーダンスを有する。
