A catheter comprising an inner tubular member, an outer tubular member movable relative to the inner tubular member, and an expandable member coupled to a distal end of the inner tubular member. The expandable member has an inner chamber and is changeable between a contracted configuration and an expanded configuration. A pressure chamber is defined by the proximal seal, the distal seal, the outer surface of the inner tubular member, and the inner surface of the outer tubular member, in fluid communication with the fluid flow port, and fluid introduced into the pressure chamber through the fluid flow port is A force is applied to the position seal to bias the outer tubular member proximally. [Selection] Figure 4C内側管状部材と、内側管状部材に対して可動である外側管状部材と、内側管状部材の遠位端部に結合された拡張可能部材とを含むカテーテル。拡張可能部材は、内側チャンバーを有し、収縮構成と膨張構成との間で変化可能である。圧力チャンバーが、近位シール、遠位シール、内側管状部材の外面、及び外側管状部材の内面によって画定され、流体フローポートと流体連通し、流体フローポートを通して圧力チャンバーに導入された流体は、近位シールに力を加えて外側管状部材を近位方向に付勢する。【選択図】図４Ｃ
