Medical device

A medical device comprising:

• a sheath that has a longitudinal axis and that is provided with a flexible section provided at least at a distal end section of the sheath, the flexible section being configured to have flexibility so as to be deformed between a first shape extending along the longitudinal axis and a second shape bent in a direction intersecting the longitudinal axis;
• a deformation assisting member having a longitudinal axis extending parallel to the longitudinal axis of the sheath, the deformation assisting member being configured to be attached to the sheath so as to be movable along a surface of the sheath;
• a position adjustment part connected to a proximal end section of the sheath, the position adjustment part being configured to adjust a relative position of the deformation assisting member with respect to the sheath;
• and
• a curved section provided at one of the flexible section and one longitudinal section of the deformation assisting member and having a bent shape in a natural state,
• wherein the position adjustment part adjusts the relative position of the deformation assisting member with respect to the sheath, thereby causing the deformation assisting member to impart to the flexible section a driving force for causing deformation between the first shape and the second shape, according to an adjustment amount adjusted by the position adjustment part.