Inside the blood vessel which is crooked, drive operation is possible even with when the catheter becomes deformed, at the same time in order to offer the catheter where the drive section is crooked easily, is superior in holding power of the drive section, it has the fluid drive type actuator which possesses with the restraint component which restrains the expansion to catheter minor axis direction of the balloon and the aforementioned balloon with catheter minor axis section of the aforementioned fluid drive type actuator, the tube which does not expand and contract in catheter extended shaft direction by comparison with the aforementioned balloon, eccentricity doing on one side of the aforementioned restraint component, it uses the catheter which is provided.屈曲した血管内で、カテーテルが変形した場合でも駆動操作が可能であり、且つ駆動部が容易に屈曲し、その駆動部の保持力に優れたカテーテルを提供するために、バルーンと前記バルーンのカテーテル短軸方向への膨張を拘束する拘束部材とを有する流体駆動型アクチュエータを備え、前記流体駆動型アクチュエータのカテーテル短軸断面では、前記バルーンと比較してカテーテル長軸方向に伸縮しないチューブが、前記拘束部材の一側に偏心して設けられているカテーテルを用いる。
